EPA-660/2-74-049
JUNE 1974
Environmental Protection Technology Series
Selected Irrigation Return Flow
Quality Abstracts, 1972 - 1973
Office of Research and Development
U.S. Environmental Protection Agency
Washington, D.C. 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3* Ecological Research
U. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and .non-point sources of
pollution. This work provides the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
standards.
EPA REVIEW NOTICE
This report has been reviewed by the Office of Research and
Development, EPA, and approved for publication. Approval does
not signify that the contents necessarily reflect the vievs
and policies of the Environmental Protection Agency, nor does
mention of trade names or commercial products constitute
endorsement or recommendation for use.
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EPA-660/2-74-049
June 1974
SELECTED IRRIGATION RETURN FLOW
QUALITY ABSTRACTS 1972-1973
Third Annual Issue
by
Gaylord V. Skogerboe
Wynn R. Walker
Ray S. Bennett
Betsy J. Zakely
Grant No. R-800426
Program Element 1BB039
Dr. James P. Law, Jr., Project Officer
Robert S. Kerr Environmental Research Laboratory
Environmental Protection Agency
Ada, Oklahoma 74820
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
For sale by the Superintendent of Document!, U.S. Government Printing Office, Washington, D.C. 20402 - Price $3.85
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ABSTRACT
Research related to the quality of irrigation return flow is being conducted
at numerous institutions .throughout the western United States. Related work is
also underway at other institutions in the United States, as well as other
portions of the world. Approximately 100 sources of material have been
searched for articles pertinent to the National Irrigation Return Flow Research
and Development Program. These articles describe water quality problems resul-
ting from irrigated agriculture, potential technological solutions for control-
ling return flows, recent research pertinent to return flow investigations, and
literature associated with institutional constraints in irrigation return flow
quality control.
The first annual issue of SELECTED IRRIGATION RETURN FLOW QUALITY ABSTRACTS
covered publications printed in 1968 and 1969, while the second annual issue
lists publications printed in 1970 and 1971. This third annual issue lists
publications printed in 1972 and 1973. This report was submitted in fulfill-
ment of Grant Number R-800426 under the sponsorship of the Office of Research
and Development, Environmental Protection Agency.
Key Words: Fertilizers, Irrigated Land, Irrigated Systems, Irrigation Water,
Nitrates, Phosphates, Return Flow, Salinity, Water Pollution Effects, Water
Pollution Sources, Water Quality Control.
ii
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FOREWARD
The third annual issue of SELECTED IRRIGATION RETURN FLOW QUALITY ABSTRACTS
has been compiled from approximately 100 sources of material covering calendar
years 1972 and 1973. This compilation has attempted to include technological and
institutional articles that would be pertinent to action programs regarding the
control of water quality degradation resulting from irrigated agriculture.
The state-of-the-art report, "Characteristics and Pollution Problems of
Irrigation Return Flow" prepared by the Utah State University Foundation contains
a bibliography of articles pertinent to Irrigation Return Flow Quality
Control. The references in this bibliography include articles and reports prior
to 1968. The first annual issue of SELECTED IRRIGATION RETURN FLOW QUALITY
ABSTRACTS listed publications appearing in calendar years 1968 and 1969, while
the second annual issue listed publications appearing in calendar years 1970
and 1971.
The third annual issue contains approximately 600 abstracts of documents pub-
lished during calendar years 1972 and 1973. The abstracts have been placed
into sections according to the category and subgroup classifications used by
the Water Resources Scientific Information Center (WRSIC) as published in the
report, "Water Resources Thesaurus." The abstracts have been forwarded to
WRSIC for inclusion in their bi-monthly publication, "Selected Water Resources
Abstracts."
iii
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TABLE OF CONTENTS
Section page
I WATER CYCLE - GENERAL (Group 02A) 1
II WATER CYCLE - PRECIPITATION (Group 02B) 6
III WATER CYCLE - SONW, ICE AND FROST (Group 02C) 7
IV WATER CYCLE - EVAPORATION AND TRANSPIRATION (Group 02D) 8
V WATER CYCLE - STREAMFLOW AND RUNOFF (Group 02E) 25
VI WATER CYCLE - GROUNDWATER (Group 02F) 30
VII WATER CYCLE - WATER IN SOILS (Group 02G) 63
VIII WATER CYCLE - LAKES (Group 02H) 151
IX WATER CYCLE - WATER IN PLANTS (Group 021) 152
X WATER CYCLE - EROSION AND SEDIMENTATION (Group 02J) 160
XI WATER CYCLE - CHEMICAL PROCESS (Group 02K) 166
XII WATER SUPPLY AUGMENTATION AND CONSERVATION - SALINE WATER
CONVERSION (Group 03A) 170
XIII WATER SUPPLY AUGMENTATION AND CONSERVATION - WATER YIELD
IMPROVEMENT (Goup 03B) 171
XIV WATER SUPPLY AUGMENTATION AND CONSERVATION - USE OF WATER
IN IMPAIRED QUALITY (Group 03C) 172
XV WATER SUPPLY AUGMENTATION AND CONSERVATION - CONSERVATION
IN DOMESTIC AND MUNICIPAL USE (Group 03D) 176
XVI WATER SUPPLY AUGMENTATION AND CONSERVATION - CONSERVATION
IN INDUSTRY (Group 03E) 177
XVII WATER SUPPLY AUGMENTATION AND CONSERVATION - CONSERVATION
IN AGRICULTURE (Group 03F) 178
XVIII WATER QUANTITY MANAGEMENT AND CONTROL - CONTROL OF WATER ON
THE SURFACE (Group 04A) 208
XIX WATER QUANTITY MANAGEMENT AND CONTROL - GROUNDWATER
MANAGEMENT (Group 04B) 237
XX WATER QUANTITY MANAGEMENT AND CONTROL - EFFECTS OF MAN'S
NON-WATER ACTIVITIES (Group 04C) 248
XXI WATER QUANTITY MANAGEMENT AND CONTROL - WATERSHED PROTECTION
(Group 04D) 249
XXII WATER QUALITY MANAGEMENT AND PROTECTION - IDENTIFICATION
OF POLLUTANTS (Group 05A) 251
XXIII WATER QUALITY MANAGEMENT AND PROTECTION - SOURCES OF
POLLUTION (Group 05B) 254
XXIV WATER QUALITY MANAGEMENT AND PROTECTION - EFFECTS OF
POLLUTION (Group 05C) 292
iv
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TABLE OF CONTENTS (Cont'd)
Section Page
t/XXV WATER QUALITY MANAGEMENT AND PROTECTION - WASTE TREATMENT
PROCESSES (Group 05D) .297
XXVI WATER QUALITY MANAGEMENT AND PROTECTION - ULTIMATE DISPOSAL
OF WASTES (Group 05E) 304
o/XXVII WATER QUALITY MANAGEMENT AND PROTECTION - WATER TREATMENT
AND QUALITY ALTERATION (Group 05F) . 305
XXVIII WATER QUALITY MANAGEMENT AND PROTECTION - WATER QUALITY
CONTROL (Group 05G) 307
XXIX WATER RESOURCES PLANNING - TECHNIQUES OF PLANNING (Group 06A) 314
XXX WATER RESOURCES PLANNING - EVALUATION PROCESS (Group 06B) 317
XXXI WATER RESOURCES PLANNING - WATER DEMAND (Group 06D) 318
XXXII WATER RESOURCES PLANNING .-. WATER LAW AND INSTITUTIONS
(Group 06E) 320
XXXIII WATER RESOURCES PLANNING - ECOLOGIC IMPACT OF WATER
DEVELOPMENT (Group 06G) 323
XXXIV RESOURCES DATA - DATA ACQUISISTION (Group 07B) 324
XXXV RESOURCES DATA - EVALUATION, PROCESSING AND PUBLICATION
(Group 07C) 327
XXXVI ENGINEERING WORKS - STRUCTURES (Group 08A) 328
XXXVII ENGINEERING WORKS - HYDRAULICS (Group 08B) 329
XXXVIII ENGINEERING WORKS - HYDRAULIC MACHINERY (Group 08C) 333
XXXIX ENGINEERING WORKS - SOIL MECHANICS (Group 08D) 334
XXXX ENGINEERING WORKS - RAPID EXCAVATION (Group 08H) 335
XXXXI SCIENTIFIC AND TECHNICAL INFORMATION - ACQUISITION AND
PROCESSING (Group 10A) 336
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ACKNOWLEDGEMENTS
The excellent cooperation of the reading room staff at the Engineering Research
Center and the library staff at Colorado State University has been very
important in accomplishing the work reported herein.
The efforts of Ms. Barbara Mancuso, Ms. Reva Bennett, and Ms. Lee Kettering
in preparing the necessary forms which are forwarded to the Water Resources
Scientific Information Exchange are sincerely appreciated.
The typing of this final report has been the result of organization by Ms.
Betsy Zakely and painstaking efforts by Martha Badgley.
The scope of this literature abstracting effort has been delineated jointly
by the senior author and the Project Officer, Dr. James P. Law, Jr.,
Program Director, Agricultural Wastes Section, Treatment and Control
Research, Robert S. Kerr Environmental Research Laboratory, Environmental
Protection Agency, Ada, Oklahoma. The efforts .of the Project Officer
in meeting with project personnel numerous times to review the abstracting
process have been very helpful and much appreciated.
vi
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Section I
WATER CYCLE
GENERAL (GROUP 02A)
72-73:02A-001
ROLE OF SUBSURFACE FLOW IN GENERATING SURFACE RUNOFF: I. BASE FLOW CONTRIBUTIONS
TO CHANNEL FLOW,
Freeze, R. A.
Thomas J. Watson Research Center, Yorktown Heights, N.Y.
Water Resources Research, Vol. 8, No. 3, p 609-623, June 1972. 8 fig, 2 tab,
19 ref.
Descriptors: *Base flow, *Surface-groundwater relationships, *Mathematical
models, *Numerical analysis, Unsteady flow, Saturated flow, Unsaturated flow,
Water balance, Surface waters, Groundwater, Groundwater movement, Infiltration,
Rainfall-runoff relationships, Hydrograph analysis.
The mechanism of base flow generation and the nature of watershed response in
base flow dominant streams are examined with a deterministic mathematical model
that couples three-dimensional, transient, saturated-unsaturated subsurface flow
and one-dimensional, gradually varied, unsteady channel flow. The channel flow
model uses the single step Lax-Wendroff explicit technique to solve numerically
the full shallow water equations. The subsurface flow model uses the line
sucessive overrelaxation technique to solve numerically the Jacob-Richards
diffusion equation. The results of the, simulations on a hypothetical basin
suggest a wide variability in watershed response under the influence of varia-
tions in rainfall properties, antecedent moisture conditions, and saturated and
unsaturated subsurface hydrogeologic properties. This evidence of a wide
range of watershed response functions leads to skepticism toward black box rain-
fall-runoff correlations, the concept of basin linearity, and the rationality of
hydrograph separation.
72-73:02A-002
ROLE OF SUBSURFACE FLOW IN GENERATING SURFACE RUNOFF: 2. UPSTREAM SOURCE
AREAS,
Freeze, R. A.
Thomas J. Watson Research Center, Yorktown Heights, N.Y.
Water Resources Research, Vol. 8, No. 5, p 1272-1283, October 1972. 11 fig,
27 ref.
Descriptors: *Model studies, *Storm runoff, *Simulation analysis, *Rainfall-
runoff relationships, *Subsurface runoff, Subsurface flow, Soil water movement,
Surface-groundwater relationships, Mathematical models, Water level fluctuations.
Runoff simulation carried out with a deterministic mathematical model that
couples channel flow and saturated-unsaturated subsurface flow provides theoreti-
cal support for runoff-generating mechanisms observed in the field. There are
stringent limitations on the occurrence of subsurface storm flow as a quanti-
tatively significant runoff component. Only on convex hi11slopes that feed
deeply incised channels, and then only when saturated soil conductivities are
very large, is subsurface storm flow a feasible mechanism. On concave slopes
with lower permeabilities, and on all convex slopes, hydrographs are dominated
by direct runoff through very short overland flow paths from precipitation on
transient near-channel wetlands. On these wetlands surface saturation occurs
from below because of rising water tables that are fed by vertical infiltration
rather than by lateral subsurface flow. These conclusions, when coupled with
field observations that show classic Hortonian overland flow to be a rare
occurrence in vegetated humid environments, have implications in planning field
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instrumentation networks, and in designing hydrologic response models.
72-73:02A-003
STOCHASTIC MODELING OF TEMPERATURE AND FLOW IN RIVERS,
McMichael, F. C., and Hunter, J. 8.
Carnegie-Mellon University, Pittsburgh, Pennsylvania, Division of Sponsored
Research.
Water Resources Research, Vol. 8, No. 1, p 87-98, February 1972. 12 fig,
2 tab, 9 ref.
Descriptors: *Time series analysis, ^Stochastic processes, "Statistical models,
*Water temperature, Discharge (Water), *Streamflow forecasting, Simulation
analysis. Synthetic hydrology, Mathematical models.
Identifiers: ^Stochastic models.
Forecast models using historical time series data for temperature and flow may
be constructed by means of parametric time series models. The new methods and
two examples of data illustrative of the iterative procedures necessary to
construct a good forecast model are given. The daily water temperature and
Ohio River discharge at Wheeling, West Virginia, for January 1, 1963-December
31, 1968, provide the raw material for the models. The methods are easily
extended to other problems.
72-73s02A-004
APPLICATION OF THE CONVOLUTION EQUATION TO STREAM-AQUIFER RELATIONSHIPS,
Hall, F. R., and Moench, A. F.
New Hampshire University, Durham, Institute of Natural and Environmental
Resources.
Water Resources Research, Vol. 8, No. 2, p 487-493, April 1972. 9 fig, 13 ref.
Descriptors: *Hydrologic equation, *Surface-groundwater relationships,
^Mathematical studies, Equations, Base flow. Recession curves, Transmissivity,
Infiltration, Recharge, Hydrogeology, Water level fluctuations, Discharge
(Water), Diffusivity.
Flow and head variations in stationary linear stream-aquifer systems may be
obtained through application of the convolution equation. Four highly idealized
cases involving finite and semifinite aquifers, with and without semipervious
stream banks, are considered. Equations for the instantaneous unit impulse
response function, the unit step response function, and the derivative of the
unit step response function are given for each case. Head fluctuations in the
aquifer due to an arbitrarily varying flood pulse are obtained for the cases
involving a finite aquifer with and without a semipervious stream bank. Flow
in and out of the aquifer at the stream bank is determined for the same cases
and demonstrates the value of the convolution equation in evaluating the base
flow. Head variations, and to a lesser extent flow variations, are apparently
relatively insensitive to variations in aquifer diffusivity.
72-73:02A-005
WATERSHED PHYSICS: SOIL VARIABILITY CRITERIA,
Rogowski, A. S.
Agricultural Research Service, Beltsville, Maryland, Hydrograph Laboratory.
Water Resources Research, Vol. 8, No. 4, p 1015-1023, August 1972. 2 fig,
5 tab, 27 ref.
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Descriptors: *Unsaturated flow, *Hydraulic conductivity, *Mathematical models,
*Soil water movement, Variability, Statistical methods, Statistical models,
Saturated flow, Groundwater basins.
Identifiers: *Watershed physics.
Variability criteria were developed for input parameters to the moisture
characteristic and hydraulic conductivity models. The parameters include the
water contents at air entry and at 15 bars as well as the hydraulic conductivity
used in matching the predicted values with the experimental values at saturation.
The available data suggest that the water contents at 15 bars and at air entry
have a normal distribution whereas the hydraulic conductivity has a log normal
distribution. The distributions of water contents and conductivities for
different soil series with depth and over an area are illustrated. In watershed
studies a soil may be considered uniform with depth or over an area if the co-
efficient of variation with respect to water content does not exceed 15% at 15
bars and 10% at air entry and the logarithmic standard deviation for hydraulic
conductivity is less than log 2. If these conditions are met, the water con-
tents at 15 bars and at air entry as well as the saturated conductivities may be
averaged.
72-73:02A-006 '
A SIMULATED ENVIRONMENTAL MODEL OF TEMPERATURE, EVAPORATION, RAINFALL, AND SOIL
MOISTURE,
Jones, J. W., Colwick, R. F., and Threadgill, E. D.
United States Department of Agriculture, Agricultural Research Service,
State College, Mississippi.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 5,
p 366-372, March-April, 1972. 8 fig, 2 tab, 24 ref.
Descriptors: *Environment, *Computer models, *Plant growth, Plant-Soil-Water-
relationships. Model studies, Soil moisture. Climatic data. Precipitation
(atmospheric). Environmental effects.
This study was designed to develop an environment model for crop production or
other biological systems to provide inputs of daily rainfall, temperature,
evaporation, and soil moisture variations with depth. The weather model was
run on the computer and 10 years of simulated data were shown to compare very
closely with observed data for State College. The soil moisture model produced
results that fell within 10 percent of the observed data for at least 43 days.
The models developed in this paper can be used to provide basic environmental
variables for use in crop production simulations for studying complete systems
at various locations. The methods of simulation developed show promise for
studying and projecting environmental factors.
(See 72-73:066-002)
72-73:02A-007
DEVELOPING SIMULATION MODELS,
James, W.
McMaster University, Department of Civil Engineering and Engineering Mechanics,
Hamilton, Ontario, Canada.
Water Resources Research, Vol. 8, No. 6, p 1590-1592, December, 1972. 3 fig,
1 ref.
Descriptors: *Mathematical models, *Computer models, *Systems analysis. Model
studies, Simulation analysis, Operations research, Synthetic hydrology,
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Scheduling.
Simulation models are commonly resolved in time and space beyond the integrity
of available field observations. Input data are fudged accordingly, and,
ultimately, expensive simulation models coexist with inadequate data bases.
Such manipulation is necessary in sensitivity analysis, but a compromise between
data collection and model extrapolation must be found. The rationale for the
systematic development of a simulation model and the concomitant data collection
program is presented in this paper and should be useful for managing difficult
simulation studies.
72-73:02A-GOS
ROLE OF MODELS IN GROUNDWATER MANAGEMENT,
Weber, E. M., and Hassan, A. A.
California Department of Water Resources, Sacramento.
Water Resources Bulletin, Vol. 8, No. 1, p 198-206, February, 1972. 3 fig,
1 tab.
(See 72-73:02F-065)
Descriptors: *Water management (applied), *Surface-groundwater relationships,
*Water resources development, *Computer models. Mathematical models, Groundwater
resources, Water utilization, Groundwater potential, Aquifer management, Ground-
water, Surface waters.
To integrate operation of ground and surface water supplies into their manage-
ment plans, decision-makers must be able to predict the effects of various
alternative modes of operation and meteorological conditions on the groundwater
basin. Many types of models have been used for simulating the behavior of
groundwater basins under these changes. Analog simulators, analog computers,
and digital computers have been employed for model development. To achieve
plausible models, detailed hydraulic and hydrologic characteristics are
required, such as data on transmissivity, storage, and net deep percolation.
These data are used in the equations that form the model. Water quality, which
cannot be separated from quantity, deserves equal consideration. Recently,
considerable efforts have been made to develop water quality prediction tools
through the use of modeling techniques.
72-73:02A-009
VOLUME BALANCE METHOD FOR COMPUTING INFILTRATION RATES IN SURFACE IRRIGATION,
Lai, R., and Pandya, A. C.
Orissa University of Agriculture and Technology, Bhubaneswar, India.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 1, p 69-72, January-February, 1972. 4 fig, 2 tab, 7 ref.
(See 72-73:04A-021)
72-73:02A-010
GROUNDWATER MANAGEMENT
Peters, H. J.
California Department of Water Resources, Division of Resources Development,
Sacramento.
Water Resources Bulletin, Vol. 8, No. 1, p 188-197, February 1972. 1 fig.
(See 72-73:02F-067)
Descriptors: *Water management (applied), *Surface-groundwater relationships,
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*Groundwater resources, Groundwater potential. Water utilization, Aquifer
management, Base flow, Groundwater, Surface waters.
Groundwater management concepts have changed over the years, with today's
concept a comprehensive integrated use of the four groundwater resources with
surface water resources to provide the most efficient water service for an area
in terms of quantity, quality, and cost. Complete geologic and hydrologic
understanding provides a base for formulation of plans which can utilize the
techniques of artificial recharge, control of sea water intrusion, and variation
of pumping patterns while protecting the resources through proper well construc-
tion and abandonment, placement of sanitary landfills, and liquid waste disposal.
Plan formulation involves varying recharge and extraction amounts while main-
taining the total of pumped groundwater and developed surface water equal to
the projected demand. Physical limitations of the system must be recognized to
assure reality of the plans. Legal constraints should not be placed on the
plan formulation process. A present worth or other technique is used to
provide an economic comparison among plans. Implementation will entail
development of legal and organizational structure, with the most difficult
problems relating to the management organization in terms of boundaries and
powers.
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Section II
WATER CYCLE
PRECIPITATION (Group 02B)
72-73:028-001
HUMIDITY EFFECTS ON YIELD AND WATER RELATIONS OF NINE CROPS,
Hoffman, G. J.
United States Salinity Laboratory, Riverside, California.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 1,
p 164-167, January-February, 1973. 2 fig, 3 tab, 12 ref.
Descriptors: *Humidity, *Crop response, Mist, Moisture, Precipitation (atmos-
pheric). Water vapor. Yield equations. Water utilization.
The purpose of this paper is to summarize the effect humidity can have on the
growth, yield, and water relations of nine crops grown under essentially the
same controlled environmental conditions. Having essentially the same environ-
ment makes comparisons among crops possible. The data have been taken from
various experiments conducted at the U. S. Salinity Laboratory to establish
the interaction between atmospheric relative humidity and the salt tolerance
of the crop. All the data reported here are from the nonsaline treatments.
The results are therefore independent of salinity.
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Section III
WATER CYCLE
SHOW, ICE, AND FROST (Group 02C)
72-73:02C-001
SPRING DISCHARGE OF AN ARCTIC RIVER DETERMINED FROM SALINITY MEASUREMENTS
BENEATH SEA ICE,
Walker, H. J.
Louisiana State University, Baton Rouge, Coastal Studies Institute.
Water Resources Research, Vol. 9, No. 2, p 474-480, April 1973. 4 fig, 3 tab,
15 ref.
Descriptors: *Discharge measurement, *Streamflow, *Alaska, *Ice breakup, *Sea
ice, Mixing, Salinity, Stream gages, Discharge (Water), Permafrost, Arctic.
Identifiers: *Colville River (Alaska).
Salinity measurements under sea ice seaward of the Colville delta in Alaska
made possible the calculation of the river's discharge during breakup in
1971. Between May 27 and June 15 the discharge was 5.70 billion cu m, which
is about 58% of the total for 1971. The entire drainage basin of the Colville
River is confined to the zone of continuous permafrost. In winter both surface
water and groundwater freeze, and the river ceases to flow. This cessation of
flow allows seawater to occupy completely the delta front and to replace river
water in the lower reaches of the river. After flushing the saltwater from
the river channels, the floodwater intrudes between sea ice and seawater as
it flows into the ocean.
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Section IV
WATER CYCLE
EVAPORATION AND TRANSPIRATION (Group 02D)
72-73:020-001
MODEL FOR PREDICTING EVAPORATION FROM A ROW CROP WITH INCOMPLETE COVER,
Ritchie, J. T.
Agricultural Research Service, Temple, Texas, Blackland Conservation Research
Center.
Water Resources Research, Vol. Q, No. 5, p 1204-1213, October 1972. 5 fig,
2 tab, 23 ref.
Descriptors: *Evapotranspiration, *Evaporation, *Transpiration, *Sorghum,
Lysimeters, Water balance, *Texag, Consumptive use, Humidity, Winds, Model
studies. Mathematical models. Temperature.
A model is presented for calculating the daily evaporation rate from a crop
surface. It applies to a row crop canopy situation in which the soil water
supply to the plant roots is not limited and the crop has not come into an
advanced stage of maturation of senescence. The crop evaporation rate is
calculated by adding the soil surface and plant surface components (each of
these requiring daily numbers for the leaf area index), the potential evapora-
tion, the rainfall, and the net radiation above the canopy. The evaporation
from the soil surface (Es) is calculated in two stages: (1) the constant rate
stage in which Es is limited only by the supply of energy to the surface and
(2) the falling rate stage in which water movement to the evaporating sites
near the surface is controlled by the hydraulic properties of the soil.
The evaporation from the plant surfaces (Ep) is predicted by using an empirical
relation based on local data, which shows how Ep is related to the leaf area
index. The model was used to obtain the total evaporation rate E equals
Es plus Ep of a developing grain sorghum canopy in central Texas. The results
agreed well with values measured directly with a weighing lysimeter.
72-73:020-002
EVAPOTRANSPIRATION FROM A GREASEWOOD-CHEATGRASS COMMUNITY,
Harr, R. D., and Price, K. R.
Battelle-Pacific Northwest Laboratories, Richland, Washington, Ecosystems
Department.
Water Resources Research, Vol. 8, No. 5, p 1199-1203, October 1972. 3 fig,
2 tab, 12 ref.
Descriptors: *Evapotranspiration, *Phreatophytes, *Water loss, *Drawdown,
*Semiarid climates, Transpiration, Soil moisture, Groundwater, Arid lands,
Water level fluctuations. Water balance. Climates, Pacific Northwest U.S.
Identifiers: Greasewood, Cheatgrass.
Groundwater elevation, soil moisture, and precipitation were monitored to
evaluate the components of water loss from two greasewood-cheatgrass communities
in south central Washington. Annual evapotranspiration was 21-25 cm, 18-31%
of which was the transpiration of groundwater. The greatest loss from the
system was the evapotranspiration of stored soil moisture, but this moisture
was unavailable to greasewood. Water use is a function of depth of water up
to 2.3 meters, but a more complicated mechanism operates at depths of up to
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13 meters. Shrub height, canopy coverage, and total leaf surface area are
inversely related to depth of water, and the rate of water use is in turn
directly related to these features.
72-73:02D-003
EFFECT OF USING AVERAGED DATA ON THE COMPUTED EVAPORATION,
JOBSON, H. E.
Geological Survey, Fort Collins, Colorado.
Water Resources Research, Vol. 8, No. 2, p 513-518, April 1972. 1 fig, 10 ref.
Descriptors: *Evaporation, *Data processing, *Water loss, Equations, Mass
transfer. Humidity, Winds, Statistics, Meteorological data, Oklahoma.
Identifiers: *Lake Hefner (Oklahoma).
Because it is seldom necessary to determine the total evaporation from a
body of water for short periods of time, meteorologic data that have been
averaged over long intervals of time and the semiempirical mass transfer
equation are often used to determine the total evapoartion. The effect of
averaging wind speeds and temperatures on the computed evaporation is discuss-
ed. Data collected during a 15-month interval at Lake Hefner near Oklahoma
City, Oklahoma, were analyzed. Each set of data represents the average meteor-
ologic conditions during a 30-minute time interval. From these data the
effect of averaging for periods of 3 hours, 1 day, and 1 month was determined.
The value of the coefficient in the semiempirical mass transfer formula is
independent of the averaging time when this time is less than 1 day in length.
The frequency distribution of the averaging error was determined for each
averaging period. An averaging error larger than plus or minus 5% occurred
about 3% of the time for 3-hour averages and about 20% of the time for daily
averages. Averaging periods should be shorter than 1 month in situations
similar to those at Lake Hefner.
72-73:02D-004
ERRORS IN OUTPUT OF HYDROLOGIC MODELS DUE TO ERRORS IN INPUT POTENTIAL
EVAPOTRANS PIRATION,
Parmele, L. H.
Agricultural Research Service, University Park, Pennsylvania.
Water Resources Research, Vol. 8, No. 2, p 348-359, April 1972. 10 fig, 1 tab,
12 ref.
Descriptors: *Mathematical models, *Evapotranspiration, *Water balance,
*Simulation analysis, Synthetic hydrology, Systems analysis, Rainfall-runoff
relationships.
Identifiers: Error analysis (Model studies), Stanford Watershed Model.
To give some perspective to the importance of accurate evapotranspiration (ET)
input data to hydrologic models, computed output from three hydrologic models
was considered as the true watershed response. Variations in the form of
random fluctuations and fixed biases were introduced into the potential
evapotranspiration (Pet) input data of the test models. By leaving the other
inputs and parameters unchanged, the effect of evapotranspiration on stream-
flow under the regulation of the other components in the model is
shown. A constant bias of 20% in the Pet input data has a cumulative effect
and results in considerable error in the computed hydrograph peaks and
recession characteristics, whereas the influence of the random error on esti-
mated streamflow was generally not measurable for the watersheds and models
studied.
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72-73:020-005
SOIL-MOISTURE EFFECTS OF CONVERSION OF SAGEBRUSH COVER TO BUNCHGRASS COVER,
Shown, L. M., Lusby, G. C., and Branson, F. A.
Geological Survey, Lakewood, Colorado.
Water Resources Bulletin, Vol. 8, No. 6, p 1265-1272, December 1972. 3 fig,
1 tab, 8 ref.
Descriptors: *Evapotranspiration, *Grasses, *Sagebrush, *Soil water, Colo-
rado, *Evapotranspiration control. Soil moisture. Consumptive use, Sediment
yield, Runoff, Vegetation effects, Water yield improvement, Water balance.
Precipitation, soil moisture, runoff, and vegetation were measured on two,
5- to 10-acre, big sagebrush watersheds and two, equally small, beardless
bluebunch wheatgrass watersheds that were converted from big sagebrush in 1967.
The watersheds are located near Wolcott, Colorado, at an elevation of 7,200
feet, and are mantled with 2 to 3 feet of silty clay soils. Annual precipita-
tion was about 13.5 inches; about 9 inches occurred as rain or snow from
April through October and about 4.5 inches accumulated as a snowpack from
November through March. Evapotranspiration was about 2 inches greater in
1968 and 1 inch greater in 1969 from the sagebrush watersheds than from the
grass watersheds. With a mature stand of grass in 1970 and 1971 the differ-
ences in evapotranspiratioh were within the range of differences measured
during the 3-year calibration period when all four watersheds were sagebrush.
Water use was similar in the top 1 foot of soil but slightly more water was
used by the grass in the 1- to 2-foot zone and more water was being used by
the sagebrush below 2 feet. Soil-water potential data indicated tha t only
the big sagebrush used a small amount of water from the fractured shale at
depths below 40 inches. Sagebrush used more water in August and September
than the grass.
72-73:020-006
PEAK WATER REQUIREMENTS OF CROPS IN SOUTHERN IDAHO,
Wright, J. L., and Jensen, M. H.
Agricultural Research Service, Kimberly, Idaho, Snake River Research Center.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR2, p 193-201, June 1972. 4 fig, 8 ref.
Descriptors: *Evapotranspiration, *Climatic data, *Lysimeters, *Estimating
equations, *Alfalfa, Irrigation practices, Frequency analysis, Winds, Arid
lands, Micrometeorology, Crop response, Advection, *Idaho.
Identifiers: *Potential evapotranspiration, *Crop roughness.
Because of increasing water costs, the nature of many new sprinkler systems
and because many areas like southern Idaho produce high-value crops that are
extremely sensitive to moisture stress, capacities of new irrigation systems
must be designed to closer tolerances. Two years of lysimeter measurements of
evapotranspiration (ET) and the associated energy balance components were
used to develop and verify procedures for estimating ET from meteorological
data. Peak water use requirements for well-watered alfafa were determined for
southern Idaho from frequency distributions of mean ET rates for 1-day, 3-day,
7-day, 15-day, and 30-day averaging periods. The daily ET computed showed
large daily variations and demonstrated the need for frequency analysis and
precise engineering planning for such arid regions. For the period of May
through August, the peak single-day rate exceeded 0.4 in/day (10 mm). The
peak 30-day period was from July 11 through August 10. As such information
becomes available, it increases the need for yield estimates and economic
return relationships of crops when managed at the various probability levels
of peak ET rate.
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72-73:02D-007
CENTRAL CALIFORNIA EVAPOTRANSPIRATION FREQUENCIES,
Pruitt, W. O., von Oettingen, S., Morgan, D. L.
California University, Davis, Department of Water Science and Engineering.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR2, Paper 8941, p 177-184, June 1972. 2 fig, 9 ref.
Descriptors: *Evapotranspiration, ^Frequency analysis, *Irrigation design,
Variability, Statistics, Statistical methods, Probability, Climatology, Lysi-
tneters, Soil-water-plant relationships, "California.
Identifiers: *Davis (California).
Frequency distribution patterns of daily evapotranspiration are presented for
an irrigated grass cover grown in a highly sensitive weighing lysimeter at
Davis, California, over a 10-year period. In response to climate variation,
patterns ranged from highly skewed ones in winter to very close to normal
distributions in midsummer. The importance of basing irrigation-system design
on a careful analysis of probably variation of evapotranspiration rather than
on long-term mean monthly data was dramatically illustrated. Even for crop
and soil conditions requiring very infrequent irrigations, a system design
must be some 15% higher than the 10-year monthly mean of 0.26 in. per day for
June or July. In order to cover 99% of the cases under a crop-soil combination
with only 1 in. of readily available moisture, the peak design rate would need
to be 0.36 in. per day.
72-73:020-008
COASTAL CALIFORNIA EVAPOTRANSPIRATION FREQUENCIES,
Nixon, P. R., Lawless, 6. P., and Richardson, G. V.
Agricultural Research Service, Weslo, Texas, Soil and Water Conservation
Research Division; Agricultural Research Service, Beltsville, Maryland; and
Agricultural Research Service, Fort Collins, Colorado.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR2, p 185-191, June 1972. 3 fig, 3 ref.
Descriptors: *Evapotranspiration, *Lysimeters, ^Frequency analysis, *Coasts,
*Valleys, Topography, Crops, Advection, Climatic data, *California, Winds,
Growth stages, Grasses, Temperature.
Identifiers: *Crop roughness.
year-round mild temperatures moving through gradual gradations characterize
the climate of the coastal valleys of central California more than do clearly
defined seasons. Because of advection cooling, fog and clouds along the
Pacific Coast, the climate of these coastal valleys is influenced to some
degree by maritime conditions. Examples of these influences are presented with
data collected in a coastal valley 8 miles (13 km) from the ocean near Lompoc,
California. The data are from 1 cu m hydraulical-weighing lysimeters containing
irrigated perennial rye grass as an evapotranspiration (ET) reference crop.
Because of the inaccuracy of ET prediction equations all climatic data were
ignored. Monthly frequency distributions of daily ET and frequency distribu-
tions of 1-day through 30-day mean ET summer rates are presented. Although it
would be very desirable to have more than the 2-1/4 yr of data that were
available, it was felt that the frequency based on these data should consider
that distance from the ocean has an important effect on ET rates in coastal
valleys. Crop roughness and stage of growth are also influencing factors as
well as ocean breezes and topography. Peak ET rates from field crops in this
coastal valley can be 15-20% greater than rates of the aerodynamicslly smooth
rye grass.
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72-73:020-009
MAXIMUM POTENTIAL EVAPOTRANSPIRATION FREQUENCY-EAST CENTRAL U. S.,
McGuinness, J. L., and Parmele, L. H.
Agricultural Research Service, Coshocton, Ohio, North Appalachian Experimental
Watershed.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR2, Paper 8942, p 207-214, June 1972. 3 fig, 3 tab,
11 ref, append.
Descriptors: *Evapotranspiration, *Statistics, *Distribution patterns, Vari-
ability, Probability, Irrigation, Planning, Lysimeters, Frequency analysis.
In the east-central United States maximum 1-day, 7-day, 15-day, and monthly
values of evapotranspiration as measured by a lysimeter, and potential evapo-
transpiration as estimated by a computed lake evaporation are log-normally
distributed. Equations were developed to estimate the two parameters of this
distribution for any duration from 1 day to 1 month during the April to November
season. A generalization of the data is made to a broad area of the east-
central United States.
72-73:020-010
FREQUENCY OF POTENTIAL EVAPOTRANSPIRATION RATES IN CENTRAL GREAT PLAINS,
Rosenberg, N. J.
Nebraska University, Lincoln, Department of Horticulture and Forestry.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR2, p 203-206, June 1972. 2 fig, 2 ref.
Descriptors: *Evapotranspiration, *Lysimeters, *Soil moisture, *Advection,
*Great Plains, Crop response. Soybeans, Alfalfa, Nebraska, Agronomic crops.
Irrigation efficiency.
Identifiers: *Potential evapotranspiration, *Soil water potential
As part of a study designed to improve crop water use efficiency, daily water
use (ET.) rates have been measured with precision lysimeters in an irrigated
field in eastern Nebraska. Irrigation water was supplied whenever tensiometers
and neutron probe access tubes indicated soil water potentials approaching 1
bar in the top 90 cm of soil. Daily ratios of evapotranspiration to net
radiation were often greater than 1 for alfalfa and soybeans and therefore
indicate strong advection in the region. Maximum ET for both crops has been
approximately 12 mm per day. Seasonal frequency distributions of daily ET
by a well-watered soybean crop are presented as an aid to irrigation design in
the eastern Great Plains region. July is the greatest water use month because
full canopy cover has been achieved and advection is high.
72-73:020-011
WATER DEFICITS-IRRIGATION DESIGN AND PROGRAMMING,
Hagan, R. M., and Stewart, J. I.
California University, Davis.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR2, p 215-237, June, 1972. 2 fig, 2 tab, 124 ref.
(See 72-73:03F-010)
12
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72-73:020-012
SIMULATION OF SALT CEDAR EVAPOTRANSPIRATION,
Hughes, W. C.
Colorado University, Denver.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR4, Paper 9415, p 533-542, December, 1972. 6 fig,
6 ref, 3 append.
Descriptors: *Evapotranspiration, *Tamarisk, *Winds, Phreatophytes, Equations,
Albedo, Stomata, Water loss.
Identifiers: *Roughness (Aerodynamic), *Penman equation.
The use of the Penman equation, as modified by Van Bavel and Monteith, for
simulating evapotranspiration from dry plant surfaces requires knowledge of the
surface albedo, surface roughness height and stomatal resistance. These
variables were determined for salt cedar using measured values of salt cedar
evapotranspiration. The equation was insensitive to variations in albedo so
that values normally ascribed to vegetated surfaces could be used. The surface
roughness height for salt cedar, 305 cm to 396 cm in height, was found to be
37 cm. The relative insensitivity of the equation to small variations in sur-
face roughness height allowed for deviations of 10 cm to 15 cm without appreci-
able error. Stomatal resistance was varied seasonally from 0.3 sec per cm to
over 5 sec per cm and was indirectly related to temperature and directly
related to wind speed. Stomatal resistance was related to water depth only
during seasons when the plants were inactive.
72-73:020-013
NITROGEN FERTILIZATION AND CLIPPING EFFECTS ON GREEN NEEDLEGRASS (STIPA
VTRIDULA TRIN.): II EVAPOTRANSPIRATION, WATER USE EFFICIENCY, AND NITROGEN
RECOVERY.
White, L. M., and Brown, J. H.
Montana State University, Bozeman, Department of Agronomy.
Agronomy Journal, Vol. 64, No. 4, p 487-490, July-August 1972. 3 fig, 4 tab,
17 ref.
Descriptors: *Forage grasses, *Fertilizers, *Evapotranspiration, *Water
utilization, *Plant growth regulators. Efficiencies, Consumptive use. Soil-
water-plant relationships, Distribution patterns, Soil water. Nitrate, Nitrogen
compounds, Nitrogen, Soil chemical properties. Limiting factors, Great Plains,
Semiarid climates. Crop production, Grasslands, Dry farming, Moisture stress,
Wilting.
Identifiers: *Clipping, *Green Needlegrass, *Nitrogen recovery.
Soil water and nitrogen (N) are the major factors limiting forage production
in the semiarid Great Plains grasslands. Effects of N fertilization and
clipping of dryland green needlegrass upon evapotranspiration (ET), water-use
efficiency (WUE) and N fertilizer recovery are reported. N was broadcast at
0.70 and 140 kg of N/ha in November 1968; Green needlegrass (Stipa viridula
Trin.) was either left undipped or clipped to a 5-cm height five times during
1969 at 21-day intervals. Needlegrass showed visual signs of water stress
when water was deficient in the surface 30 cm of soil On undipped plots, 80
per cent of the ET was from this depth. WUE of undipped grass increased during
May and June and decreased during July, but that of clipped plants decreased
from May through July. N fertilization increased and clipping decreased WUE.
Average N recoveries with higher application rates were 22 percent for the
first year and 8 per cent for the second. N recovery was highest with 70 kg
of N/ha and frequent clipping. Low N recovery was not due to leaching. At the
13
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end of the first crop season, 7 per cent of the 70 kg N/ha applied and 17
per cent of the 140 kg of N/ha applied the previous year remained in the soil
as nitrate-N. Soil water in the 0 to 30-cm soil depth controlled grass wilt-
ing.
72-73:020-014
EVAPORATION OF WATER FROM SAND, 1: EXPERIMENTAL SET-UP AND CLIMATIC INFLUENCES,
Hellwig, D. H. R.
National Institute for Water Research, Windhoek (South-West Africa), Regional
Laboratory.
Journal of Hydrology, Vol. 18, No. 2, p 93-108, February 1973. 8 fig, 9 tab,
7 ref.
Descriptors: *Evaporation, *Alluvial channels, *Alluvial aquifers, *Evapori-
meters, *Climates, Water loss, Humidity, Soil water, Sands, Underflow, Surface-
groundwater relationships, Water temperature, Diurnal.
The influence of climate on rate of evaporation from sand was studied in South
African alluvial channels. Solar radiation is the principal factor affecting
evaporation. Air temperature affects evaporation only indirectly. Both rate
of evaporation and air temperature result from the energy supplied by solar
radiation. The effect of the relative humidity is far outweighed by other
climatic factors. At times wind had a marked effect on evaporation. Under
the conditions prevailing at the test site, climatic factors complemented each
other in changes of evaporation. The temperature of the water at the water
table did not appear to be an imporatnt factor; it influenced evaporation
indirectly by conveying radiation energy and was in itself affected by evapora-
tion.
72-73:020-015
EVAPORATION OF WATER FROM SAND, 2: DIURNAL VARIATIONS,
Hellwig, D. H. R.
National Institute for Water Research, Windhoek (South-West Africa), Regional
Laboratory,
Journal of Hydrology, Vol. 18, No. 2, p 109-118, February 1973. 5 fig, 2 tab,
17 ref.
Descriptors: *Evaporation, *Alluvial channels, *Alluvial aquifers, *Evapori-
meters, *Climates, Water loss. Humidity, Soil water, Sands, Underflow, Surface-
groundwater relationships, Water temperature, Diurnal.
In evaporation tests with moist sand, an evaporation peak was observed just
before sunrise. Neither the vapor pressure gradient between water table and
atmosphere, nor the fact that the vapor pressure difference between water
table and atmosphere exceeded the vapor pressure deficit of the air during
the night, could fully explain this phenomenon. The temperature difference
between that of the water table and that of the atmosphere correlated well
with evaporation during the night and seemed to be a determining factor during
that period.
72-73:020-016
AN AERODYNAMIC FORMULA TO COMPUTE EVAPORATION FROM OPEN WATER SURFACES,
Lakshman, G.
Saskatchewan Research Council, Saskatoon.
14
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Journal of Hydrology, Vol. 15, No. 3, p 209-225, March 1972. 17 fig, 1 tab,
15 ref, 2 append.
Descriptors: *Evaporation, *Winds, *Reservoir evaporation, Humidity, Climatol-
ogy, Meteorology, Mass transfer, Advection, Temperature, Vapor pressure,
Canada.
Identifiers: Aerodynamics.
A formula to compute evaporation from open water surfaces is derived using wind
profile characteristics. The mass transfer coefficient is given as a function
of the shape and size of the water body in addition to the turbulent boundary
layer parameters. The formula has been applied successfully to lakes and
reservoirs of areas ranging from a fraction of an acre to thousands of acres.
It is also given in a simplified form for application to cases where the wind
profile measurements are not made.
72-73:020-017
DRYLAND EVAPORATIVE FLUX IN A "SUBHUMID CLIMATE: IV. RELATION TO PLANT WATER
STATUS,
Ritchie, J. T., and Jordan, W. R.
Agricultural Research Service, Temple, Texas, Soil and Water Conservation
Research Division,
Agronomy Journal, Vol. 64, No. 2, p 173-176, 1972. Illus.
Descriptors: Climates, Evapotranspiration, Moisture, Soils, Transpiration,
Water balance, *Subhumid climates.
Identifiers: Dryland, *Evaporative flux, *Leaf, Plants, Sorghum-Bicolor-M,
*Plant-water status.
Seasonal trends in relative water content (RWC) of grain sorghum (Sorghum
bicolor (L.) Moench) were measured concurrently with evaporation rates during
a prolonged drying cycle in 1969. When the available soil water supply was
depleted beyond a critical threshold, called the lower limit for potential
evaporation (LLEO), daily evaporation rates began to decline substantially
below the level of energy available for evaporation. Before the LLEO threshold
was reached, midday leaf RWC values were approximately 0.90. Afterwards,
these values declined in proportion to measured decreases in daily evaporation.
Early morning RWC values did not decrease significantly until 8 days after
evaporation began to decline. Leaf stomatal response to soil water deficit
was evident when daylight leaf diffusion resistances changed from 2 sec/cm
before the LLEO threshold to about 25 sec/cm 10 days after the threshold was
reached. Plant water status can be used in conjunction with measured changes
in soil water content to define the amount of soil water extractable by
plant roots for a particular crop, soil, and climate between the maximum water-
holding capacity of the soil and the LLEO threshold. These critical soil
water parameters can be applied to predicting evaporation in 2 stages: a
freely evaporating stage when evaporation is limited by the amount of energy
available for evaporation? and a falling rate stage when evaporation declines
below the potential rate. An equation is proposed for predicting evaporation
in the falling stage as an exponentially decreasing function of time after the
LLEO threshold is reached.
72-73:020-018
DRYLAND EVAPORATIVE FLUX IN A SUBHUMID CLIMATE: III. SOIL WATER INFLUENCE,
Ritchie, J. T., Burnett, E., and Henderson, R. C.
Agricultural Research Service, Temple, Texas, Soil and Water Conservation
Research Division.
15
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Agronomy Journal, Vol. 64, No. 2, p 168-173, 1972. Illus.
Descriptors: Climates, Bvapotranspiration, Evaporation, Plow, *Soil water,
Transpiration, Wilting.
Identifiers: Dryland, *Evaporative flux, *Gossypium-D-Sp, Rooting, *Sorghum-
Bicolor-M, Unsaturated.
The relationship between evaporative rates of field-grown cotton (Gossypium
Sp.) and grain sorghum (Sorghum bicolor (L.) Moench) and the soil water status
for use in predicting evaporation on watersheds was studied. Soil water content
and soil water matric potential of Houston Black clay were measured throughout
complete growing seasons for cotton and grain sorghum concurrently with measure-
ments of the daily evaporation rate. Evaporation rates were independent of
the soil water status until soil water was depleted beyond a threshold value.
This threshold, termed the lower limit for potential evaporation (LLEO), was
reached when approximately 18.2 cm of water had been removed from a soil
profile initially wet. Another 6.5 cm of sd.1 water was extracted at a
decreasing rate before exaporation practically stopped. Evaporation rates
after the LLEO threshold was reached were practically independent of the
energy available for evaporation and depended on the rooting distribution
and the water movement to the roots. An analysis of the soil water transmission
characteristics after the threshold LLEO was reached showed that practically
all the water extracted by plant roots was moving from the volume of soil
immediately surrounding the roots. The need for growing crops with deep,
dense root systems in dryland for maximum utilization of stored soil water is
indicated.
72-73:02D-019
EVAPOTRANSPIRATION FROM SOYBEAN AND SORGHUM FIELDS,
Brun, Lynn J., Kanemasu, Edward T., and Powers, William L.
Kansas State University, Manhattan, Department of Agronomy.
Agronomy Journal 64(2): 145-148, 1972. Illus.
Descriptors: *Evapotranspiration, Heat, Indexing, Soils, Transpiration.
Identifiers: Flux, Leaf, *Sorghum-M, *Soybean-D, Stomatal resistance.
The evapotranspiration model, presented by Monteith (1965) and later tested by
Black et al. (1970) on a loosely structured snap bean (Phaseolus vulgaris)
canopy, was used to separate soil evaporation and transpiration on soybean
(Glycine max (L.) Calland) and sorghum (Sorghum bicolor (L.) 'Pioneer No 846')
canopies during the growing season. Soil evaporation was estimated as the net
radiation below the crop canopy minus the soil heat flux. Stomatal resistance
was determined with the diffusion porometer (Kanemasu et al. 1969). Potential
evapotranspiration, soil evaporation, and transpiration rates were determined
on an hourly basis. The sum of transpiration and soil evaporation was compared
to the lysimetric estimates of evapotranspiration. The model and the lysimeters
were in agreement, except under conditions of high atmospheric demand when the
model underestimated actual evapotranspiration. The model showed the propor-
tion of water lost as transpiration was closely correlated to leaf area index
(LAI) with transpiration at approximately 5096 of the total evapotranspiration
at a LAI of 2 and as much as 95% at a LAI of 4.
72-73:02D-020
AN IRRIGATION SCHEDULING MODEL WHICH INCORPORATES RAINFALL PREDICTIONS,
Rochester, E. W., and Busch, C. D.
16
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Auburn University, Agricultural Experiment Station, Agricultural Engineering
Department, Auburn, Alabama.
Water Resources Bulletin, Vol. 8, No. 3, p 608-613, June, 1972. 5 fig, 5 ref.
Descriptors: "Irrigation, *Scheduling, *Irrigation practices. Supplemental
irrigation. Soil moisture, Evapotranspiration, Consumptive use, Agricultural
engineering, Mathematical models, Computer models.
Identifiers: Irrigation scheduling.
In humid areas appreciable amounts of rainfall complicate irrigation scheduling.
This rainfall tends to give supplemental water application a low priority.
Irrigation may be delayed until there is not enough time to cover the crop
area before some drought damage occurs. To improve the management of irrigation
systems, a scheduling model has been developed. The model's water application
decisions incorporate climatological records, soil-plant data, current pan
evaporation and rainfall, the number of fields to be irrigated, and 5-day
weather forecasts. The model updates the soil moisture conditions, predicts
impending water depletion, and if supplemental water is needed both the field
priority and amounts to be applied is indicated for each of the next 5 days.
Errors introduced through the use of forecasts and long-term pan evaporation
records have been slight because of the tri-weekly updating. Also natural
rains which restore the root zone to maximum water holding capacity prevent
long-term bias.
72-73:02D-021
SOME EVIDENCE OP STOMATAL RESTRICTION OF EVAPORATION FROM WELL-WATERED PLANT
CANOPIES,
Shepherd, W.
Commonwealth Scientific and Industrial Research Organization, Division of
Atmospheric Physics, Aspendale, Victoria, Australia.
Water Resources Research, Vol. 8, No. 4, p 1092-1095, August, 1972. 2 tab,
4 fig, 10 ref.
Descriptors: *Evapotranspiration, *Stomata, *Water requirements, Soil-water-
plant relationships, Consumptive use, Hydrologic cycle, Soil moisture, Moisture,
Water conservation.
Various aspects of stomatal control of evaporation and their practical signifi-
cance have been considered in a recent exchange of opinions in this journal.
The present paper describes some considerable departures from potential evapora-
tion rates observed under conditions of generous soil water supply. These
departures occurred on days of high potential rates and represented reductions
of up to about 2096 from levels that might otherwise have been expected under
the prevailing atmospheric conditions. However, the reductions represented
only a few percent of the seasonal or annual evaporation. Accompanying symptoms
of plant moisture stress are discussed.
72-73:020-022
WATER REQUIREMENTS OF ROSTERED IRRIGATION SCHEMES,
Fitzgerald, P. D., and Arnold G. C.
Department of Agriculture, Ashburton, New Zealand.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR1, p 91-96, March, 1972. 1 fig, 3 tab, 4 ref.
(See 72-73:04A-025)
17
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72-73:02D-023
DIURNAL SOIL-WATER EVAPORATION: TIME-DEPTH-FLUX PATTERNS,
Jackson, R. D., Kimball, B. A., Reginato, R. J., and Nakayama, F. S.
Agricultural Research Service, Phoenix, Arizona, Water Conservation Laboratory.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 505-509, July-
August 1973. 8 fig, 6 ref.
Descriptors: *Evaporation, *Soil Water movement, Drying, Air-earth interfaces,
Lysimeters, Evaporimeters.
Time-depth patterns of soil water flux in the 0- to 9-cm zone of a bare field
soil are described for four 24-hour periods at 3, 7, 16, and 37 days after
irrigation. On day 3, the flux at 0 cm (Evaporation) dominated the flux
patterns for all depths. As the soil dried, this flux decreased and those
at the greater depths gradually became dominant. On all 16 days of measure-
ment, downward flux was observed below 1 to 3 cm during several hours between
sunrise and early afternoon. Only one period of downward flux was observed
for day 3, but 2 to 4 periods were noted for subsequent days. These patterns
demonstrate the dynamic nature of soil water flux in the surface zone of a
field soil subjected to diurnally varying environmental conditions.
72-73:020-024
PREDICTION OF EVAPORATION FROM HOMOGENEOUS SOIL BASED ON THE FLOW EQUATION,
Gardner, H. R.
Agricultural Research Service, Fort Collins, Colorado.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 513-516, July-
August 1973. 3 fig, 3 tab, 3 ref.
Descriptors: *Evaporation, *Soil water movement, *Water loss, Diffusivity,
Air-earth interfaces. Equations, Soil moisture. Soil water.
Identifiers: Soil water evaporation.
Evaporation of water from columns packed with McGrew loamy sand was measured
for three different sequences of six water additions and evaporation times
totaling 60 days. These treatments were: (1) equal amounts of water added
and equal times evaporated, (2) equal amounts applied and varied evaporation
times, and (3) various amounts applied and equal evaporation times. The
average times and amounts were the same in all treatments, and the total losses
were approximately the same. A solution for the diffusivity equation for soils
of finite depth was used to predict the cumulative water loss for all the
treatments event by event and by an averaging technique. The predicted amounts
were all within 6.5% of the total cumulative evaporation.
72-73:020-025
DIURNAL SOIL-WATER EVAPORATION: CHLORIDE MOVEMENT AND ACCUMULATION NEAR THE
SOIL SURFACE,
Nakayama, F. S., Jackson, R. D., Kimball, B. A., and Reginato, R. J.
Agricultural Research Service, Phoenix, Arizona, Water Conservation Laboratory.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 509-513, July-
August 1973. 9 fig, 10 ref.
Descriptors: *Evaporation, *Chemical precipitation, *Soil water, Soil water
movement. Water chemistry. Diurnal, Chlorides, Soil chemistry, Leaching, Mass
transfer, Ion transport.
18
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Movement and accumulation of chloride at shallow depths (0 to 9 cm) were studied
in a bare soil following an irrigation, chloride accumulation in the 0- to 0.5-
and 0- to 1-cm depth increments followed a diurnal pattern but out-of-phase
from the soil water content during the first few days after irrigation. The
diurnal amplitude of chloride decreased with time as the soil progressively
dried. At 1- to 2-cm and deeper depths, diurnal cycling of the chloride content
was not measurable, whereas cycling in the water content was evident. Most
of the total chloride accumulation at the shallowest depth occurred in the
early stages of drying. However, chloride movement was detected as low as
4% volumetric water content or approximately 1,000 bars soil water potential.
72-73S02D-026
WATER VAPOR MOVEMENT THROUGH MULCHES UNDER FIELD CONDITIONS,
Kimball, B. A.
United States Water Conservation Laboratory, Phoenix, Arizona.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 813-818, Novem-
ber-December, 1973. 3 fig, 2 tab, 24 ref.
Descriptors: *Mulching, *Evaporation control, Soil conservation, Water conser-
vation. Water loss. Water vapor.
The loss of water vapor through 0.5-, 1-, and 2-cm depths of water repellent
mulches was measured under field conditions with lysimeters. Concurrent
measurements were made of wind velocities, air vapor pressures, and tempera-
tures at the soil-mulch interfaces. Mulches used included 0.5-, 1-, and 2-mm
glass beads and 1-mm glass bead aggregates. By assuming that the relative
humidity of the soil air at the soil-mulch interface was essentially 100%,
effective diffusion coefficients for field conditions were calculated. The
average effective diffusion coefficient for afternoon periods was 1.26 times
greater than the molecular diffusion coefficient. An error analysis revealed
that the value could have been as low as 0.90 or as high as 1.63, but these
values would have been realized only if the effects of several possible syste-
matic errors were completely additive. Little correlation was found between
wind velocity and effective diffusion coefficient. However, the generally low
range in wind velocities observed and the smoothing required for the reduction
of the lysimeter data may have prevented detection of such a correlation.
72-73r02D-027
APPLICATION OF THE GRID SQUARE TECHNIQUE TO MAPPING OF EVAPOTRANSPIRATION,
Foyster, A. M.
Exeter University (England), Department of Geography.
Journal of Hydrology, Vol. 19, No. 3, p 205-226, July 1973. 14 fig, 30 ref.
Descriptors: *Mapping, *Evapotranspiration, Runoff, Precipitation (Atmospheric),
*Computer programs. Water balance, *Data processing, Hydrologic data, *Climatic
data, Networks, Meteorological data.
A method of producing potential evapotranspiration maps for a part of southwest
England uses grid-based extrapolation. Penman's equation was chosen to estimate
potential evapotranspiration because it uses readily available climatic data
and it produces estimates that closely resemble evaporation pan or lysimeter
readings. A computer-oriented technique in association with grid data provides
the best solution. A grid approach not only simplifies the production of maps
but also facilitates data storage, retrieval, and processing because each square
is defined by a pair of Cartesian coordinates. The easy referencing quality of
-------
a grid also allows the processing of data from subgroups of squares. Data
from topographic maps is used to assemble a physiographic data file for each
grid square. This file is then used as a set of independent variables in
multiple regression analysis in order to extrapolate the climatological data
over a grid. In this way, a file of climatological data is set up for every
grid square. Values of 2 theoretical meteorological parameters are derived
for each square by substituting values of physiographic parameters and daily
declination of the sun and the earth-sun radius vector, into Okanoue's equation.
This formula gives values of maximum possible incident radiation and maximum
possible sunshine hours. Penman's monthly potential evapotranspiration esti-
mates are then calculated by applying Penman's formula to the climatic and
meteorological information for each individual grid square.
72-73:020-028
EVAPORATION OP WATER FROM SAND, 3: THE LOSS OP WATER INTO THE ATMOSPHERE FROM
A SANDY RIVER BED UNDER ARID CLIMATIC CONDITIONS,
Hellwig, D. H. R.
National Institute for Water Research, Ausspannplatz, Windhoek, South West
Africa.
Journal of Hydrology, Vol. 18, No. 3/4, p 305-316, March 1973. 2 fig, 5 tab,
17 ref.
Descriptors: *Evaporation, *Evapotranspiration, Consumptive use, Water loss,
Phreatophytes, Arid Climates.
The Penman formula was applied to calculate evaporation and evapotranspiration
losses under arid climatic conditions from a sandy river bed. Good agreement
with measured results was obtained. The loss of water into the atmosphere from
a river bed covering 8300 ha was estimated to be 76 million cubic meters per
year. Evapotranspiration contributed 68% and permanently wet areas 19.5%
to the total water loss. The rest evaporated from temporary wet areas. Sub-
stantial volumes of water can possibly be gained by the removal of phreato-
phytes.
72-73:020-029
EVAPORATION OF WATER FROM SAND, 4: THE INFLUENCE OF THE DEPTH OF THE WATER-
TABLE AND THE PARTICLE SIZE DISTRIBUTION OF THE SAND,
Hellwig, D. H. R.
National Institute for Water Research, Ausspannplatz, Windhoek, South West
Africa.
Journal of Hydrology, Vol. 18, No. 3/4, p 317-327, March, 1973. 6 fig, 5 tab,
11 ref.
Descriptors: *Evaporation, Consumptive use. Water loss, Arid climates. Water
table. Depth, Groundwater.
Experiments were carried out to determine the influence of the depth of the
water-table and the particle size of sand on evaporation of water from sand.
Dropping the water-table in sand, with a mean diameter of 0.53 mm, below 60 cm
will practically prevent evaporation losses. The coarseness of the sand does
not effect evaporation if the water-table is kept at the sand surface. If the
water-table is kept below the sand surface, evaporation decreases with the
coarseness of the sand and with the depth of the water-table. Evaporation
from an open water surface was 8% higher than from water-saturated sand, most
probably due to higher energy storage in a body of water resulting in a greater
20
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temperature gradient between the evaporation surface of the water and the air
during the night, as compared to a water-saturated sand.
72-73:020-030
L'EVAPORATION D'UN BAG D'EAU LIBRE - SA SIGNIFICATION RESTREINTE,
Bultot, F.f and Dupriez, G. L.
Section d'Hydrologie de 1'Institut Royal Meteorologique, Uccle (Belgique).
Journal of Hydrology, Vol. 20, No. 1, p 83-95, September 1973. 2 fig, 2 tab,
9 ref.
Descriptors: *Solar radiation, *Evaporation, Evapotranspiration.
There is no simple relation nor even a strong correlation between daily evapora-
tions measured by means of a water pan and potential evapotranspirations of
neighboring natural surfaces. Generally, the evaporation of the pan is reduced
in a certain proportion due to the fact that the incident global solar radia-
tion penetrates partially into the water and because consequently a portion of
the radiant energy flux is not caught by the surface. Nevertheless, during
rainy periods and also under certain meteorological conditions, the evaporation
of the pan is increased paradoxally as a result of a fast transfer of heat
from underlying water layers towards the surface, by turbulent diffusion.
72-73:020-031
A WEIGHING SYSTEM FOR LYSIMETERS,
Voisey, P. W., and Hobbs, E. H.
Agriculture Canada, Research Branch, Engineering Research Service, Ottawa,
Ontario.
Canadian Agricultural Engineering, Vol. 14, No. 2, p 82-84, December 1972.
3 fig, 25 ref.
Descriptors: *Lysimeters, *Weight, Evapotranspiration, Soil moisture. Soil
water. Consumptive use, Soil-water-plant relationships.
A technique is described for weighing lysimeters using a strain gage load cell
and an electronic indicating system. The nominal weight of the lysimeter is
eliminated from the measurement by offsetting the indicator zero electrically
using a weight. This increases the possible resolution and accuracy of
measurement. In the example described, weight changes of £22.7 kilogrammes
in lysimeters weighing 180 kilogrammes with a resolution of 0.045 kilogrammes
and accurate within 0.090 kilogrammes were measured. Weighing of 36 such
lysimeters could be accomplished in 2 hours.
72-73:020-032
CONSERVING WETLAND WATER BY SUPRESSING EVAPORATION,
Rutherford, R. J., and Byers, G. L.
New Hampshire University, Water Resources Center, Durham, New Hampshire.
Canadian Agricultural Engineering, Vol. 15, No. 1, p 9-11, June, 1973. 1 fig,
2 tab, 8 ref.
Descriptors: *Evaporation, *Evaporation Control, Water loss, Consumptive use,
Evapotranspiration, Chemcontrol, monomolecular films, Thin films, Water conser-
vation.
21
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Evapotranspiration from the muck and peat bog of Jewell Pond in Stratham, New
Hampshire, was 1.7 times as great as the evaporation from the open water sur-
face during the summer of 1969. The wetland released 16.9 centimeters of water
from storage during the same period. During the summer of 1970, an evaporation
retardant was used to reduce open water evaporation. The objective of this
management practice was to increase water yields and augment water supplied
during dry months. The retardant successfully reduced evaporation by 47 per-
cent. Additional water supplies obtained by the use of evaporation retardants
could be used for domestic and commercial consumption.
72-73:02D-033
CROP COOLING WITH SPRINKLERS,
Hobbs, E. H.
Agriculture Canada, Research Branch, Research Station, Lethbridge, Alberta.
Canadian Agricultural Engineering, Vol. 15, No. 1, p 6-8, June, 1973. 3 fig,
1 tab, 15 ref.
Descriptors: "Temperature control, "Sprinkling, Coolants, Water, Temperature,
Irrigation practices, Surface irrigation, Sprinkler irrigation. Climates.
Irrigated plots of potatoes and bush beans were sprinkled intermittently with
water whenever the ambient air temperature exceeded 80 degrees Fahrenheit.
Conventional but low-volume irrigation equipment was used to apply the cooling
water at a net theoretical application rate of 0.026 inches per hour. Over a
3-year period and 88 applications this sprinkling rate effectively reduced
plant canopy air temperature. The average temperature reduction was 6 Fahren-
heit degrees but reductions as large as 16 Fahrenheit degrees occurred. The
amount of cooling achieved was dependent upon the weather prevailing during
cooling. Humidity exerted the greatest single influence, maximum air tempera-
ture was next in importance, and wind was less well related. The multiple
regression equations indicate the amount of temperature reduction likely to
be achieved with field-type sprinkler irrigation equipment.
72-73:02D-034
CALCULATION OF EVAPORATION FROM MEASUREMENTS OF SOIL WATER AND THE SOIL WATER
CHARACTERISTIC,
Stammers, W. N., Igwe, O. C., and Whiteley, H. R.
Guelph University, School of Engineering, Guelph, Ontario, Canada.
Canadian Agricultural Engineering, Vol. 15, No. 1, p 2-5, June, 1973. 6 tab,
5 ref.
Descriptors: "Evaporation, *Soil surfaces, Evapotranspiration, Soil moisture,
Soil water, Soil types, Mathematical models.
An approach based on the existence of a plane of zero soil-water flux is used
to develop a model for calculating evaporation from soil-water measurement.
The information required is a knowledge of soil water, capillary potential
relationships for the soil considered, and soil-water content at the beginning
and end of each time period of evaporation computation. This approach yields
results that do not differ significantly from those obtained by assuming a
fixed soil depth for calculations and ignoring soil-water seepage.
22
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72-73:020-035
A MINIATURE STRIP NET RADIOMETER,
Harper, L.A.
United States Department of Agriculture, Agricultural Research Service, Watkins-
ville, Georgia.
Agronomy Journal, Vol 64, No 3, P 403-405, May-June, 1972. 4 fig, 9 ref.
Descriptors: *Solar radiation, Energy, Evaporation, Hydrologic cycle.
An inexpensive miniature strip net radiometer was constructed for average net
radiation measurement along a horizontal line in dense foliage such as short
grasses or row crops. The sensing surface was 1.3 x 40 cm and was enclosed in
a polyethlene shield for protection against wind and weather. The unit was
calibrated relative to a temperature-compensated, net-exchange radiometer, and
gave a linear response.
72-73:020-036
INCREASE IN CONDUCTIVITY OF IRRIGATION WATER DURING SPRINKLING,
Robinson, F.E.
California University, Department of Water Science and Engineering, Davis.
Agronomy Journal, Vol. 65, No. 1, p 130, January-February, 1973. 3 ref.
Descriptors: *Salinity, Sprinkler irrigation, Evaporation, Irrigation practices,
Irrigation engineering.
The test was conducted on a high evaporative demand July day to evaluate the
possible harm that could result from concentration of salinity as water is
sprinkled in an arid desert area. Catchment breakers (250 ml) were set at 19-m
intervals across a 190- x 219-m alfalfa field that was sprinkled for 19.5
hours. Conductivity of the sprinkler water increased 21% on the field edge
and 4.4% inside the field.
72-73:020-037
QUANTATIVE SOIL MOISTURE USE IN CORN GROWN UNDER CONVENTIONAL AND NO-TILLAGE
METHODS,
Hill, J.D. and Blevins, R.L.
National Weather Service, Lexington, Kentucky.
Agronomy Journal, Vol. 65, No. 5, p 945-949, November-December, 1973. 7 fig,
1 tab, 8 ref.
Descriptors: *Soil moisture, *Moisture stress, *Corn, Crop production, Crop
response, Cultivation, Farm management, Mulching.
Experiments conducted at the University of Kentucky during 1969, 1970, and
1971 compared corn production under conventional and no-tillage systems.
The presence of a killed-sod mulch in the no-tillage plots almost eliminated
the loss of moisture by direct evaporation from the soil surface during the
early growing period, but after a full crop canopy had developed, losses from
both production methods were about equal. Water loss from the soil during the
full-canopy period was compared with open pan evaporation to determine the rate
of loss under varying levels of soil moisture deficiency. The average soil
moisture deficiency during the period from about three weeks before to six
weeks after silking was related to final grain yield, and a simple linear
relationship indicated that each additional cm of water available to the plant
increased yields by about 559 kg/ha.
23
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72-73:02D-038
INFLUENCE OF SOIL WATER STATUS AND METEOROLOGICAL CONDITIONS ON EVAPORATION
FROM A CORN CANOPY,
Ritchie, J. T.
United States Department of Agriculture, Agricultural Research Service, Temple,
Texas.
Agronomy Journal, Vol. 65, No. 6, p 893-897, November-December, 1973. 3 fig,
21 ref.
Descriptors: *Evapotranspiration, *Corn, *Lysimeters, Irrigation design.
Water utilization, Crop response, Yield equations.
This study was conducted to determine actual evaporation rates of corn as
influenced by soil water status and potential evaporation rate. Actual evapor-
ation rates were measured during the 1972 growing season with a weighing lysi-
meter. Evaporation rates were found to be practically independent of the soil
water status for all existing conditions of potential evaporation. During the
season more than 20 cm of soil water was removed from the 120-cm deep profile.
Leaf diffusion resistance and leaf water potential measurements indicated
that at least 80% of the extractable soil water was freely available to plant
roots.
24
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Section V
WATER CYCLE
STREAMFLL'W AND RUNOFF (Group 02E)
72-73:022-001
NOTE ON THE FINITE ELEMENT SOLUTION OF THE DIFFUSION-CONVECTION EQUATION,
Guymon, G. L.
Alaska University, College, Institute of Water Resources.
Water Resources Research, Vol. 8, No. 5, p 1357-1360, October 1972.
1 fig, 5 ref.
Descriptors: *Finite element analysis, *Nuraerical analysis, *Diffusion,
*Convectionf Mathematical studies, Turbulence, Currents (Water), Unsteady
flow, Non-uniform flow.
An improved formulation of the finite element procedure, based on a
variational principle, yields superior results to a previous formulation of
the finite element method. Numerical dispersion, introduced into the
previous formulation by a transformation procedure that is unneccessary, is
substantially reduced by the new procedure. The improved formulation of the
problem yields a stable solution for a hypothetical stream mass transport
problem.
72-73:02E-002
FLOW ROUTING MODELS FOR STREAM SYSTEM STUDIES,
Jennings, M. E., and Sauer, V. B.
Geological Survey, Washington, D. C., Water Resources Division.
Water Resources Bulletin, Vol. 8, No. 5, p 948-956, October 1972. 11 fig,
15 ref.
Descriptors: *Routing, *Frequency analysis, *Streamflow forecasting,
Simulation analysis, Frequency curves. Regression analysis, Reservoir
operation, Water management (Applied), Unsteady flow.
Studies to determine frequency characteristics of regulated streams at
points within a stream system require the use of flow routing models. This
study compares several different flow routing methods using data from six river
reaches. Results indicate that approximate flow routing methods yield good
flow estimates when compared with observed flows. The unit response method,
recently introduced, performed as well as other approximate methods for all
reaches studied and gave better results for reaches subject to power releases.
72-73:02E-003
BORDER IRRIGATION ADVANCE AND EPHEMERAL FLOOD WAVES,
Smith, R. E.
Agricultural Research Service, Tucson, Arizona, Southwest Watershed Research
Center.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR2, p 289-307, June 1972. 13 fig, 16 ref.
Descriptors: *Mathematical models, *Floods, *Hydrology, *Irrigation,
*Infiltration, Routing, Channels, Arroyos, Flood waves, Ephemeral streams.
identifiers: *Kinematics, transmission loss.
A kinematic wave is a wave whose properties can be described by an equation of
continuity and a stage-discharge relation, implying that momentum changes are
negligible. A method is described of predicting advance rate, surface profiles
and modifications with time to kinematic wave flow over an initially dry infil-
trating plane. Point infiltration rate is considered to be a function of time
since wetting. The model developed is shown to describe 2 common hydrological
problems: border irrigation advance and attenuation in dry alluvial channels
25
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such as commonly occurs in the southwestern U.S. Numerical methods for solving
the equations developed are described and illustrated. The partial differen-
tial equations for kinematic wave movement under time-varying space-varying
lateral losses were reduced to 2 characteristic orginary differential equations
and combined with a third equation for shock movement. Sensitivity for
advance rate to the infiltration functions is shown. The model may be
used to route floods through dry infiltrating channels.
72-73:02E-004
CHANGES IN WATER YIELD OF SMALL WATERSHEDS BY AGRICULTURAL PRACTICES,
Richardson, C. W.
United States Department of Agriculture, Agricultural Research Service, Riesel,
Texas,
Transactions of the American Society of Agricultural Engineers, Vol. 15, No.
3, p 591-593, May-June, 1972. 7 fig, 5 ref.
Descriptors: *Hydrology, *Flow, Precipitation (atmospheric), Reservoir yield,
Runoff, Surface waters, Watersheds (basins).
Agricultural practices can have a significant effect on on-site runoff from
small watersheds. A simple statement that improved agricultural practices
alter by a given percentage the runoff that would have occurred if the prac-
tices were not in effect is insufficient for water yield design purposes.
The effect of conservation practices on water yield is highly dependent
on the management level that is associated with the structural measures.
Poor management practices on terraced areas may actually result in increases
in water yield. The effect of conservation practices diminishes as watershed
size becomes larger. On areas larger than about 300 acres, little effect of
conservation practices have been noted.
72-73:02E-005
AN IRRIGATION SCHEDULING MODEL WHICH INCORPORATES RAINFALL PREDICTIONS,
Rochester, E. W., and Busch, C. D.
Auburn University, Auburn, Alabama.
Water Resources Bulletin, Vol. 8, No. 3, p 608-613, June, 1972. 5 fig, 5 ref.
(See 72-73:020-020)
72-73:02E-006
INTERNATIONAL MANAGEMENT OF THE RIO GRANDE BASIN - THE UNITED STATES AND
MEXICO,
Day, J. C.
Western Ontario University, Department of Geology, London, Canada.
Water Resources Bulletin, Vol. 8, No. 5, p 935-947, October, 1972. 3 fig,
18 ref.
Descriptors: *International waters, *Rio Grande River, *International Bound.
and Water Comm., Water management (applied), United States, Mexico, Interstate
rivers.
Identifiers: International water management.
Mexico and the United States forged a common program to manage water and
related land on the Rio Grande. Actions of Rio Grande Commissions related to
stream gaging, boundary definition, and multiple-purpose construction projects
are among the more successful international water-management efforts in the
world. Cost-sharing arrangements promoted rapid completing of international
works. Joint action accomplished only part of expectations. International
developments were competitive rather than complementary until basin water
appropriation was virtually complete. Commissions were not employed to con-
sider long-range competitive water needs, or regional water requirements,
throughout the basin. International groundwater use coordination does not
exist. International structures produce less than anticipated benefits.
Hydroelectric generators are financial liabilities, irrigated acreage exceeds
26
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dependable streamflow, and soil salinization is experienced. Unanticipated
environmental changes occurred in every major program. The Rio Grande experi-
ence points to the need for society to specify goals to which the use of water
should contribute and specify priorities for water use among different sectors
of river basins and various segments of society.
72-73:02E-007
TRANSPORT OF SOIL PARTICLES BY SHALLOW FLOW,
Foster, G. R., and Meyer, L. D.
United States Department of Agriculture, Agricultural Research Service,
Lafayette, Indiana.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 1, p 99-102, January-February, 1972. 3 fig, 2 tab, 15 ref.
Descriptors: *Erosion, *Soil erosion, *Rill erosion, *Sheet erosion,
Sedimentation, Erosion rates, Sediment yield. Sediment load, Sediment
transport, Soil conservation.
The Yalin equation was selected to describe the sediment transport capacity of
overland flow for use in mathematical soil erosion models. Hydraulic
variables in the equation are simply the hydraulic radius and slope Steepness.
Soil parameters needed are particle diameter, specific gravity, and the
critical tractive force from Shields' diagram, when modified to consider
mixtures of particle sizes, the equation predicted both the total transport
rate and also the particle size distribution of the transported material.
When rilling developed, transport rate predictions were within a factor of
2 relative to actual transport rates from a bed of glass spheres. Also,
the predicted particle size distributions often agreed well with observed
distributions. When applied to a field erosion plot where the sediment
load was at transport capacity, the equation predicted sediment load within
a factor of 2.
72-73:02E-008
RECESSION FLOW IN SURFACE IRRIGATION,
Wu, I.
Hawaii University, Honolulu, Agricultural Engineering Department.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR1, p 77-90, March, 1972. 6 fig, 1 tab, 9 ref.
Descriptors: *Surface irrigation, *Irrigation efficiency, *Surface runoff,
*Recession curves. Furrow irrigation, Border irrigation, Irrigation, Irrigation
systems, Irrigation engineering, Irrigation practices, Water, Water storage,
Water flow.
The recession flow of furrow or border irrigation can be expressed as a
simple power function which is derived by assuming a linear storage of
recession flow. The flow length is expressed as a function of recession time
and a constant. The knowledge of the length of recession flow profile and
recession time is important in the evaluation of irrigation efficiency,
especially in the border irrigation which has a relatively large volume of
surface storage at the time when the inflow is shut off. Laboratory experi-
ments were conducted and field data of sugarcane furrow experiments were
applied to check the validity of the derived mathematical models. A
simple recession flow equation is also derived by considering the recession
flow as depleting water from a single shallow linear reservoir. For a
relatively short length and small slope of furrow or border, the simple
recession flow equation seems to be applicable.
72-73:02E-009
A STUDY OF FACTORS INFLUENCING THE NITROGEN AND PHOSPHORUS CONTENTS OF
NEBRASKA WATERS,
Muir, J., Seim, E. C., and Olson, R. A.
27
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Nebraska University, Lincoln.
Journal of Environmental Quality, Vol. 2, No. 4, p 466-470, October-December,
1973. 1 fig, 5 tab, 14 ref.
(See 72-73:053-064)
72-73:02E-010
THEORETICAL IRRIGATION TAILWATER VOLUMES,
Wilke, O.C.
Texas A & M University, Lubbock.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR3, p 415-420, September, 1973. 1 fig.
(See 72-73:03F-047)
72-73:02E-011
NITROGEN AND PHOSPHORUS COMPOSITION OF SURFACE RUNOFF AS AFFECTED BY TILLAGE
METHOD,
Romkens, M. J. M., Nelson, D. W., and Mannering, J. V.
United States Department of Agriculture, Agricultural Research Service,
Lafayette, Indiana.
Journal of Environmental Quality, Vol. 2, No. 2, p 292-295, April-June, 1973.
2 fig, 4 tab, 12 ref.
Descriptors: *Nitrogen, *Phosphorus, *Leaching, Nutrient removal, Cultivation,
Soil management, Fertilizers, Pollutants, Erosion, Sediments.
The effect of tillage methods on the nitrogen and phosphorus composition in
runoff water and runoff sediment from corn plots was studied on Bedford
silt loam soil by applying simulated rainstorms. Five tillage-planting systems
were compared: coulter-plant, till-plant, chisel-plant, disk and coulter-plant,
and conventional-plant. The coulter and chisel systems controlled soil
loss, but runoff water contained high levels of soluble nitrogen and phos-
phorus from surface-applied fertilizer. The disk and till systems were less
effective in controlling soil erosion, but had lower concentrations of
soluble nitrogen and phosphorus in runoff water. Conventional tillage, in
which fertilizers were plowed under, had the highest losses of soil and water
but small losses of soluble nitrogen and phosphorus. However, high percentages
of the total nutrients removed by runoff were components of the sediment
from all treatments.
72-73:02E-012
A PROGRAMMED SAMPLER FOR RUNOFF AND BEDLOADS,
Swanson, N. P.
United States Department of Agriculture, Agricultural Research Service,
Lincoln, Nebraska.
Transactions of the American Society of Agricultural Engineers, Vol. 16,
No. 4, p 790-792, July-August, 1973. 7 fig, 5 ref.
Descriptors: *Runoff, *Sampling, *Automatic control, Surface runoff, Bedload,
Flow, Soil erosion, Water erosion, Water quality, Suspended load, Bedload
samplers.
A programmed, automatic sampler that collects a sequence of composite
samples of runoff and accompanying bedloads has been in use on a feedlot re-
search installation near Lincoln, Nebraska, for over 4 years. Composited
samples are collected over 5-minute sampling periods with volumes of about
3 1. The sampler can be programmed to obtain individual samples for any
14 5-minute periods during a total of 12 hours of actual runoff. The runoff
need not be continuous. The time of collection of each sample is recorded
to relate to the runoff hydrograph and recording rain-gage chart. Bedload
particles up to 5/8 inch in diameter can enter the rotating sampler dipper,
which passes under the discharge.
28
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72-73:02E-013
MODELING OF LAND RUNOFF EFFECTS ON DISSOLVED OXYGEN,
Wallace, D. A., and Dague, R. R.
Kansas State University, Civil Engineering Department, Manhattan.
Journal Water Pollution Control Federation, Vol. 45, No. 8, p 1795-1809,
August, 1973. 17 fig, 7 tab, 10 ref.
Descriptors: ^Computer models, *Runoff, *Water pollution sources, Mathematical
models, Agricultural runoff, Agricultural watersheds, Water quality, Erosion.
A computer mathematical model to estimate the effects of agricultural land
runoff on river dissolved oxygen (DO) concentrations has been developed. The
Iowa River basin above the Coralville Reservoir was chosen as the area on
which to base the model. This area includes 237 miles of main-stem channel
and 44 tributaries draining 2,953 square miles. About 90 percent of the area
is used for farming operations. The model accounts for both surface and
subsurface inflows. Principles of open channel flow are used to describe
the flow conditions in the river. The model approximates actual river
conditions and is useful in showing the relative effects of different
sources of pollution.
72-73:02E-014
THE INTER-RELATIONSHIP OF WATER QUANTITY AND QUALITY AS A DETERMINANT OF
WATER MANAGEMENT POLICY,
Gordon, Y.
The Mitre Corporation, Westgate Research Park, McLean, Virginia.
Water Research, Vol. 16, No. 12, p 1501-1508, December, 1972. 1 fig, 2 tab,
5 ref.
Descriptors: *Water quality, *Salinity, Water supply, Irrigation, Colorado
River Basin, Colorado River, Water pollution sources.
Comprehensive water resources management includes a variety of factors,
among which are water quantity and quality, institutional and legal aspects,
and economics. Even though water quality has begun to attin some prominence,
its relation to water quantity and to water system operation has been largely
overlooked. The Colorado River system inthe United States is a case in
point. The river basin encompasses an area which is one-twelfth the size
of the continental United States. The water is utilized mainly for irrigation
of semi-arid areas in the southwestern part of the United States and in
northwestern Mexico. Despite its importance, the river system operates under
laws and regulations that are not conducive to efficiency. Consequently water
is used wastefully and a progressive deterioration in the quality of the
river water is evident. Changes in water management are recommended. The
pricing of supplied water according to its quality as well as charges for
pollution are suggested.
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Section VI
WATER CYCLE
GROUNDWATER (Group 02F)
72-73:02F-001
LAND SUBSIDENCE IN THE WESTERN STATES DUE TO GROUNDWATER OVERDRAFT,
Poland, J. F.
Geological Survey, Sacramento, California
Water Resources Bulletin, Vol. 8, No. 1, p 118-131, February 1972. 11 fig,
11 ref.
Descriptors: *Subsidence, *Land subsidence, *Withdrawal, *Groundwater, Water
table. Confined water. Irrigation water, Water wells, History, Reviews, Artifi-
cial recharge.
Development of farm lands in most of the western states has required irrigation
by surface water or groundwater, supplemental to precipitation. Pumping draft
has exceeded replenishment in many areas. Water levels have been drawn down
from 100 to 500 feet, greatly increasing the grain-to-grain stress or effective
overburden load on the aquifer systems in which the head depletion has occurred.
This increase in stress tends to cause compaction of the deposits and subsidence
of the land surface. The aquifer systems in the western states that have ex-
perienced appreciable compaction are chiefly confined systems. Subsidence can
be stopped by raising water levels sufficiently to eliminate excess pore
pressures in the fine-grained compressible interbeds and confining beds. In
areas of groundwater overdraft, this can be accomplished by a reduction of with-
drawal, or an increase in recharge, or both, in an amount exceeding the over-
draft. In several areas, importation of a supplemental supply has been the
solution.
72-73:02F-002
APPLICATION OF GALERKIN'S PROCEDURE TO AQUIFER ANALYSIS
Pinder, G. F., and Frind, E. O.
Geological Survey, Washington, D.C.
Water Resources Research, Vol. 8, No. 1, p 103-120, February 1972. 10 fig,
2 tab, 21 ref.
Descriptors: *Groundwater movement, *Numerical analysis. Mathematical studies,
Equations, Aquifer characteristics, Hydraulic conductivity, Transmissivity,
Water yield. Drawdown, Mathematical models.
Identifiers: Finite difference method, *Galerkin procedure.
Groundwater flow equations may be solved using the Galerkin procedure to gener-
ate the approximating equations. The integrals in the resulting equations may
be efficiently evaluated by using isoparametric quadrilateral elements and
numerical integration. A comparison of solutions for an idealized problem ob-
tained by using Galerkin techniques and finite difference techniques indicates
they achieve approximately the same degree of accuracy. A field application of
the two methods shows that the Galerkin procedure provides satisfactory solu-
tions with far fewer nodes than were required for the finite difference approach.
In selecting a method for a particular hydrologic problem the flexibility of the
irregular subspaces used in the Galerkin approach must be weighed against the
very efficient equation-solving schemes applicable to the finite difference
equations.
30
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72-73:02F-003
DRAWDOWN DISTRIBUTION AROUND WELLS PARTIALLY PENETRATING THICK LEAKY ARTESIAN
AQUIFERS,
Halepaska, J. C.
New Mexico Institute of Mining and Technology, Socorro, Department of
Geoscience.
Water Resources Research, Vol. 8, No. 5, p 1332-1337, October 1972. 2 fig,
14 ref.
Descriptors: *Groundwater movement, *Artesian aquifers, *Numerical analysis,
Drawdown, Transmissivity, Hydraulic conductivity, Storage coefficient, Mathe-
matical studies.
Identifiers: *Leaky artesian aquifers.
The differential equation governing nonsteady flow to a well in a thick leaky
system was solved by using transform techniques. Routines to tabulate the most
general solution in type curve form were developed and are available. The
limiting curve of the tabulated function is the Hantush partial penetration
type-curve. With knowledge of the geologic framework the technique can be
applied to certain field problems.
72-73:02F-004
SOLUTIONS OF HYDRODYNAMIC DISPERSION IN POROUS MEDIA,
Eldor, M., and Dagan, G.
Technion-Israel Institute of Technology, Haifa.
Water Resources Research, Vol. 8, No. 5, p 1316-1331, October 1972. 9 fig,
13 ref.
Descriptors: *Dispersion, *Tracers, *Radioisotopes, *Adsorption, *Groundwater
movement, Radioactivity, Mixing, Numerical analysis. Aquifer testing. Mathe-
matical studies, Hydrogeology, Water chemistry.
Problems of hydrodynamic dispersion of tracers in porous media with radio-
active decay and adsorption of the tracer are solved by an approximate analyti-
cal method. The flow of the carrier fluid is assumed to be steady and two
dimensional. Initially a sharp front separates two regions of different con-
stant tracer concentrations. By means of the method of outer and inner expan-
sions, approximate analytical solutions of dispersion with adsorption and
radioactive decay of the tracer have been determined. The method has been used
for a few examples of steady two-dimensional flows encountered in hydrologic
applications. Existing numerical solutions are in good agreement with the
present results. The method can be extended to solve more complex problems,
including tracers that influence the velocity field by changing the density and
the viscosity of the carrier, nonlinear adsorption isotherms, and three-dimen-
sional flows.
72-73:02F-005
VISCOUS FLOW MODEL FOR GROUNDWATER MOVEMENT,
Yen, B. C., and Hsie, C. H.
Illinois University, Urbana, Department of Civil Engineering.
Water Resources Research, Vol. 8, No. 5, p 1299-1306, October 1972. 3 fig,
14 ref.
Descriptors: *Hydraulic models, *Groundwater movement, Laminar flow, Porous
media. Viscosity, Reynolds number, Stokes law, Hydraulic similitude.
31
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Identifiers: *Hele-Shaw models, Viscous flow models.
A viscous flow model with nonuniform spacing between plates can be used to
simulate two-dimensional laminar flow in heterogeneous porous media. Such a
model can also be used to study the effects of aquifer thickness on flow in
homogeneous porous media. Mathematical expressions were developed ^rom equa-
tions of motion and continuity for flow in porous media and for flow between
closely spaced nonparallel plates to verify the theoretical background of such
model simulations. The modeling is valid for groundwater flow that obeys
Darcy's law and viscous ^low between plates with the Reynolds number within
the Stokes range.
72-73:02F-006
FIELD DETERMINATION OF THE HYDRAULIC PROPFRTIFS OF LEAKY MULTIPLE AQUIFER
SYSTEMS,
Neuman, S. P., and Witherspoon, P. A.
Volcani Institute o^~ Agricultural Research, Bet-Dagn (Israel) .
Water Resources Research, Vol. 8, No. 5, p 1284-1298, October 1972. 9 fig,
4 tab, 21 ref.
Descriptors: *Aquifer testing, *Artesian aquifers, *Confined water, *Aquitards,
*Testwells, Water levels. Drawdown, Hydraulic conductivity, Storage coefficient,
Transmissivity, Observation wells, Aquifer characteristics, Hydrogeology,
*California.
Identifiers: *Leaky artesian aquifers.
A new field method is proposed for determining the hydraulic properties of
aquifers and aquitards in leaky systems. Conventional methods of analyzing
leaky aquifers usually rely on drawdown data from the pumped aquifer alone.
Such an approach is not sufficient to characterize a leaky system; the method
requires observation wells to be placed not only in the aquifer being pumped
but also in the confining layers (aquitards}. The ratio of the drawdown in
the aquitard to that measured in the aquifer at the same time and the same
radial distance from the pumping well can be used to evaluate the hydraulic
properties of the aquitard. The new method is supported by theory and has been
applied to the coastal groundwater basin of Oxnard, California. The field
results are in good agreement with laboratory measurements.
72-73:02F-007
RADIAL FLOW IN AN INFINITE AQUIFER UNDERGOING CONVERSION FROM ARTESIAN TO
WATER TABLE CONDITIONS,
Moench, A. F., and Prickett, T. A.
Illinois State Water Survey, Urbana.
Water Resources Research, Vol. 8, No. 2, p 494-499, April 1972. 4 fig, 1 tab,
5 ref.
Descriptors: *Groundwater movement, *Artesian aquifers, *Withdrawal, *Water
table, *Drawdown, Water yield, Artesian heads, Aquifer systems, Confined water.
Pressure, Diffusion, Transmissivity, Dupuit-Forchheimer theory, Mathematical
studies. Water storage.
Identifiers: Heat-flow equations.
A closed form mathematical solution is given for water level conversion from
artesian to water table conditions due to a well discharging at a constant rate.
The solution'is obtained from the analogous case of heat flow in cylindrical
32
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symmetry in which freezing or melting takes place. A single nonleaky artesian
aquifer that is homogeneous isotropic, and infinite in areal extent is consid-
ered. The well fully penetrates the aquifer and is infinitesimal in diameter.
Dimensionless curves are given, and suggestions are made to aid in the analysis
and interpretation of the aquifer test data.
72-73:02F-008
USE OF NATURALLY OCCURRING PHENOMENA TO STUDY HYDRAULIC DIFFUSIVTTIES OF
AQUITARDS,
Davis, R. W.
Southern Illinois University, Carbondale, Department of Geology.
Water Resources Research, Vol. 8, No. 2, p 500-507, April 1972. 4 fig, 2 tab,
15 ref.
Descriptors: *Barometric efficiency, *Artesian aquifers, *Aquitards, *Water
level fluctuations, *Aquifer testing. Aquifer systems, Hydrogeology, Drawdown,
Permeability, Porosity, Confined water, Florida.
Identifiers: *Pasco County (Fla).
Measurement of the response of an artesian aquifer system to naturally occurring
stress fields can be used to determine aquitard properties. The response of an
artesian aquifer to a short-term rise of water levels can be estimated by
approximating a step function in the unconfined aquifer above it. An analysis
of the corresponding change in artesian water levels gives a value for the
aquitard hydraulic diffusivity divided by the square of the aquitard thickness.
This method is demonstrated by using data from a well field in Pasco County,
Florida. A second method uses the response of an artesian system to barometric
or tidal stresses, which is frequency dependent. It is necessary to restrict
Jacob's definition of barometric and tidal efficiencies to instantaneous stress
changes. The methods described are easily applied and serve to check the
values of a boundary condition that is assumed to be homogeneous in other
analytical approaches.
72-73:02F-009
GROUNDWATER FLOW IN AN INHOMOGENEOUS AQUIFER,
Kuiper, L. K.
Iowa State Geological Survey, Iowa City.
Water Resources Research, Vol. 8, No. 3, p 722-724, June 1972. 1 fig, 4 ref.
Descriptors: *Groundwater movement, *Hydraulic conductivity, "Heterogeneity,
*Aquifer characteristics, Numerical analysis, Mathematical models.
Identifiers: *Inhomogeneous aquifers.
An analytic solution was obtained for the groundwater head in a confined
inhomogeneous and isotropic aquifer of constant thickness. The vertical
direction component of the groundwater flow is assumed to be zero* The specific
storage is assumed to be a constant. The hydraulic conductivity varies with
distance of flow. The solution is compared graphically with the solution for
the case where hydraulic conductivity is constant and an impermeable boundary
exists. Head approaches its final value more rapidly for constant variable
hydraulic conductivity.
33
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72-73:02F-010
SOLUTION OF TRANSIENT GROUNDWATER FLOW PROBLEMS BY THE FINITE ELEMENT METHOD,
Verruijt, A.
Technische Hogeschool, Delft (Netherlands).
Water Resources Research, Vol. 8, No. 3, p 725-727, June 1972. 8 ref.
Descriptors: *Unsteady flow, *Groundwater movement, *Numerical analysis.
Mathematical models, Hydraulic conductivity, Water storage, Infiltration,
Finite element analysis.
The derivation of the basic equations of a finite element method for transient
groundwater flow problems is simplified when the approximation of the time
derivative by a finite difference equation is made before the introduction of
the variational principle. Existing programs for steady state problems can
easily be extended to the transient case in this way, and a stable numerical
procedure can be obtained.
72-73:02F-011
DRAWDOWN IN A FINITE CIRCULAR AQUIFER WITH CONSTANT WELL DISCHARGE,
Kuiper, L. K.
Iowa State Geological Survey, Iowa City.
Water Resources Research, Vol. 8, No. 3, p 734-736, June 1972. 1 fig, 4 ref.
Descriptors: *Drawdown, *Transmissivity, *Numerical analysis, Groundwater
movement, Unsteady flow, Withdrawal, Storage coefficient, Discharge (Water).
An analytical solution is derived for the groundwater head in a confined homo-
geneous, isotropic aquifer with a constant thickness and a circular impermeable
boundary around a well penetrating the entire depth of the aquifer and discharg-
ing at a constant rate. The solution is compared with the Theis solution, which
is valid for an aquifer of unlimited extent. The two solutions agree very
closely at small radial distance.
72-73:02F-012
UNSTEADY RADIAL FLOW IN AN UNCONFINED AQUIFER,
Streltsova, T. D.
Birmingham University (England), Department of Civil Engineering
Water Resources Research, Vol. 8, No. 4, p 1059-1066, August 1972. 2 fig,
14 ref.
Descriptors: *Groundwater movement, *Drawdown, *Unsteady flow, *Water table,
Equations, Saturated flow, Unsaturated flow. Storage, Permeability, Storage
coefficient, Water level fluctuations. Numerical analysis.
Identifiers: *Unconfined aquifers.
Partial differential equations were written for unsteady radial flow to a well
that is tapping an unconfined aquifer of infinite extent and discharging at a
constant rate. Complete penetration of the aquifer by the well is assumed.
Consideration is given to the observed head in a well that is screened through-
out the unconfined aquifer, as well as to the head that corresponds to the free
surface value. A relationship between the observed head and the free surface
head is assumed to have the form of a vertical transfer linear equation.
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72-73:02P-013
SOURCE AREAS AND CLIMATIC EFFECTS IN CARBONATE GROUNDWATERS DETERMINED BY
SATURATION INDICES AND CARBON DIOXIDE PRESSURES,
Shuster, E. T., and White, W. B.
Pennsylvania State University, University Park, Department of Geosciences.
Water Resources Research, Vol. 8, No. 4, p 1067-1073, August 1972. 8 fig,
1 tab, 8 ref.
Descriptors: *Water chemistry, *Karst hydrology, *Limestones, *Carbonate rocks,
*Pennsylvania, Dolomite, Leaching, Carbon dioxide, Springs, Groundwater, Geo-
chemistry, Karst .
Identifiers: *Nittany valley (Pennsylvania).
In 14 carbonate springs in Nittany valley in central Pennsylvania, the feeder
system for the springs can be characterized as conduit flow or diffuse flow
on the basis of the variability in water chemistry. Saturation indices and CO2
partial pressures were sorted into monthly groups and averaged. Conduit spring-
waters are always aggressive with respect to both calcite and dolomite. The
high variability reflects mostly variation in recharge, short residence time,
and slow kinetics of equilibration between water and rock. Diffuse springwaters
are somewhat aggressive with respect to calcite during the growing season but
become somewhat supersaturated during the winter. Waters from diffuse-flow
springs in dolomite are nearly at saturation, whereas waters from diffuse-
flow springs in limestone are always undersaturated with respect to dolomite.
The equilibrium CO2 pressures of conduit springwaters show a regular seasonal
trend having a pronounced maximum during the growing season. The CO2 content
of diffuse-flow springs is highly variable, and although the summer maximum is
present, the CO2 content also reflects variations in the CO2 production in the
catchment areas of infiltrating waters.
72-73:02F-014
USE OF SUBJECTIVE INFORMATION IN ESTIMATION OF AQUIFER PARAMETERS,
Lovell, R. E., Duckstein, L., and Kisiel, C. C.
Arizona University, Tucson, Department of Hydrology and Water Resources; and
Arizona University, Tucson, Department of Systems Engineering.
Water Resources Research, Vol. 8, No. 3, p 680-690, June 1972. 3 fig, 4 tab,
13 ref.
Descriptors: *Mathematical models, Calibrations, *Hydrogeology, *Aquifer
characteristics. Parametric hydrology, Groundwater movement, Water yield,
Model studies, Water levels, Numerical analysis.
In the calibration of aquifer models, the desire for an automated adjustment
process is sometimes in conflict with the need for subjective intervention
during the calibration process. Working from the established concept of model-
ing for unconfined aquifers with rectangular nodes, a method is described of
obtaining subjective information in addition to that customarily used in model
calibration. Such information is assembled and quantified at the same time as
the usual data are gathered for initial estimation of parameters. This infor-
mation is then introduced into an automatic adjustment process in such a way
that the calibration process can proceed without interruption until the desired
level of relative accuracy is reached, or until it is shown that the desired
level cannot be reached within the constraints assigned. A decoupling technique
that permits simultaneous adjustment of all parameters is also described. A
digital computer model of the Tucson basin aquifer is used to illustrate the
concepts and demonstrate the adjustment method.
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72-73:02F-015
DIGITAL SIMULATION OP THE BOUSSINESQ EQUATION FOR A WATER TABLE AQUIFER,
Lin, C. L.
Nova Scotia Department of Mines, Halifax.
Water Resources Research, Vol. 8, No. 3, p 691-698, June 1972. 5 fig, 16 ref.
Descriptors: *Simulation analysis, *Groundwater movement, Numerical analysis,
Dupuit-Forchheimer theory, Water levels, Permeability, Unsteady flow, Water
yield. Mathematical models, Drawdown.
Identifiers: *Boussinesq equation.
A mathematical model was developed to simulate the Boussinesq equation for a
two-dimensional water table aquifer. Transient solutions to the finite differ-
ence approximations based on an irregular mesh matrix were obtained by the
alternating direction implicit method. The precision of the model was evaluated
by comparing the volume of water pumped with the amount of water released from
storage and the amount received from a nearby recharging river. The model is
suitable for the study of transient flow in a permeable sand and gravel aquifer.
72-73:02F-016
MODELING THE PORE STRUCTURE OF POROUS MEDIA,
Farrell, D. A., and Larson, W. E.
Agricultural Research Service, St. Paul, Minnesota, Soil and Water Conservation
Research Division.
Water Resources Research, Vol. 8, No. 3, p 699-706, June 1972. 2 fig, 19 ref.
Descriptors: *Porous media, *Mathematical models, *Hydraulic conductivity,
Saturated flow, Unsaturated flow, Pores, Groundwater movement, Soil water move-
ment, Porosity, Capillary action. Capillary conductivity. Diffusion.
Identifiers: *Pore structure.
A physicomathematical alternative to capillaric modeling of the pore structure
of porous media is proposed. With this model, the hydraulic conductivity of
porous materials is determined from a 'pore domain1 characterization of the pore
space by using an appropriate conductance theory for estimating the flux contri-
bution of the various components of heterogeneous media. The proposed model is
versatile yet mathematically tractable and is capable of analyzing fluid flow
through porous materials of widely differing structure including anisotropic
and structured media. A comparative study of the predictions of this model with
those of a model widely used in soil science is made for several media.
Indiscriminate use of the soil water model may be responsible for the gross
overpredictions of hydraulic conductivity for some porous materials and also
for the reported distortions in the relationships between conductivity and the
degree of saturation for some soils.
72-73:02F-017
ACCOUNTING FOR APPARATUS-INDUCED DISPERSION IN ANALYSES OF MISCIBLE DISPLACEMENT
EXPERIMENTS,
James, R. V. and Rubin, J.
Geological Survey, Menlo Park, California, Water Resources Division.
Water Resources Research, Vol. 8, No. 3, p 717-721, June 1972. 4 fig, 1 tab,
14 ref.
Descriptors: *Dispersion, *Path of pollutants, *Porous media, *Saturated
flow, *Unsaturated flow. Mixing, Stratified flow. Solutes, Calibrations,
Laboratory tests, Equipment, Saline water intrusion. Saline water-freshwater
36
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interfaces.
Identifiers: *Miscible displacement.
In studies of hydro-dynamic dispersion in porous media there is some difficulty
in theoretically predicting experimental breakthrough curves from laboratory
columns. The greatest discrepancies occur for short-column experiments or
studies of unsaturated media. Some of the disagreement can be eliminated by
a quantitative treatment of apparatus-induced dispersion. The experimental
system is treated as a two-layer construct in which the porous medium and the
apparatus are considered as separate layers. The dispersion characteristics of
the apparatus layer are determined independently in the absence of the porous
material. The dispersion coefficient for the porous medium is obtained from
a two-layer dispersion equation. The hydrodynamic dispersion coefficients
calculated in this manner are as much as 40% lower than those obtained by the
usual one-layer approach.
72-73:02F-018
NUMERICAL SIMULATION OF FLOW IN AN AQUIFER OVERLAIN BY A WATER TABLE AQUITARD,
Cooley, R. L.
Nevada University, Reno, Center for Water Resources Research.
Water Resources Research, Vol. 8, No. 4, p 1046-1050, August 1972. 1 fig,
9 ref.
Descriptors: *Groundwater movement, *Water table, *Compressibility, *Water
level fluctuations, *Drawdown, Permeability, Storage coefficient, Numerical
analysis, Unsaturated flow, Saturated flow, Mathematical models.
Identifiers: *Unconfined aquifers.
An extension of the convolution integral produced by 'delayed yield1 theory
describes vertical flow rate at the base of a unit such as an aquitard bounded
at the top by a water table across which recharge is permitted and at the bottom
by a variable drawdown boundary. The solution requires that the water table
release water from storage instantaneously with a decline in head and that the
compressibility of both the unit and the water in it be neglected. Application
of the integral as an upper boundary condition for an aquifer underlying a
water table aquitard allows approximation of the influence of the water table
aquitard on the unsteady state head distribution in the aquifer. A simple,
efficient procedure permits the use of a numerical approximation of the integral
with a numerical groundwater flow model of the aquifer. An example solution
demonstrates the high degree of accuracy of the method.
72-73:02F-019
DETERMINATION OF THE HYDRAULIC DIFFUSIVITY OF A HETEROGENEOUS CONFINING BED,
Wolff, R. G., and Papadopulos, S. 8.
Geological Survey, Washington, D.C.
Water Resources Research, Vol. 8, No. 4, p 1051-1058, August 1972. 6 fig,
5 tab, 11 ref.
Descriptors: *Groundwater movement, *Diffusivity, *Aquicludes, *Aquitards,
*Artesian aquifers, Permeability, Numerical analysis, Mathematical models,
Piezometers, Groundwater, Confined water.
Identifiers: *Leaky artesian aquifers.
The hydraulic diffusivity of a confining bed exhibiting vertical heterogeneity
was determined by field and laboratory tests. A thin sand aquifer was pumped,
37
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and head changes were observed in the aquifer and at three vertically separated
piezometers in the overlying confining bed. A four-layer digital model was used
to analyze the field data. Hydraulic diffusivities for each layer were adjusted
in the model until calculated head changes in all piezometers closely matched
those observed in the field. Laboratory-determined hydraulic diffusivities
were several orders of magnitude smaller than the field-determined values.
Interfingering of layers within the confining bed is believed to have caused
this difference. Additional studies are needed before a general conclusion
can be reached on the value of laboratory determinations of hydraulic parameters
for heterogeneous confining beds.
72-73:02F-020
THEORY OF FLOW IN UNCONFINED AQUIFERS CONSIDERING DELAYED RESPONSE OF THE
WATER TABLE,
Neuman, S. P.
Volcani Institute of Agricultural Research, Bet-Dagan (Israel), Department of
Soil and Water.
Water Resources Research, Vol. 8, No. 4, p 1031-1045, August 1972. 12 fig,
37 ref.
Descriptors: *Groundwater movement, *Water table, *Compressibility, *Water
level fluctuations, *Drawdown, Permeability, Storage coefficient, Numerical
analysis, Unsaturated flow, Saturated flow, Mathematical models.
Identifiers: *Unconfined aquifers.
A new analytical model is proposed for the delayed response process character-
izing flow to a well in an unconfined aquifer. The present approach is based
only on well-defined physical parameters of the aquifer system. Therefore it
provides a possible physical explanation for the mechanism of delayed water
table response. The process of delayed response in a homogeneous anisotropic
phreatic aquifer can be simulated by using constant values of specific storage
and specific yield without recourse to unsaturated flow theory. In the absence
of significant infiltration at the ground surface, compressibility may often
be a much more important factor than unsaturated flow above the water table.
72-73:02F-021
SUBSURFACE HYDROGRAPH ANALYSIS BY CONVOLUTION,
Snyder, W. M., and Asmussen, L. E.
Agricultural Research Service, Athens, Georgia, Southeast Watershed Research
Center.
American Society of Civil Engineers, Journal of the Irrigation and Drainage
Division, Vol. 98, No. IR3, p 405-418, September 1972. 7 fig, 3 tab, 9 ref.
Descriptors: *Hydrograph analysis, *Infiltration, *Subsurface runoff, *Mathe-
matical models, *Rainfall-runoff relationships, Routing, Numerical analysis,
Irrigation, Subsurface irrigation. Coastal plains, *Georgia.
Identifiers: Convolution integrals.
Subsurface flow from an 0.8-acre watershed in the Southern Coastal Plain at
Tifton, Georgia is intercepted and gaged independently of any surface flows.
The hydrographs of seven flow events following significant rainfall were
analyzed by the nonlinear technique of two-stage convolution. The convolutional
model is based on two conceptual components. A characteristic function repre-
sents the three-dimensional storage capability of the soil profile and thus
could be visualized as a map of the flow potential of the drainage area. A
38
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state function expresses the movement, or routing, of the characteristic func-
tion to the outlet. This routing is the first-stage convolution and produces
a unit response function. Second-stage convolution of the response functions
with effective rainfall produces the outflow hydrograph. The consistent
results should allow identification of the parameters, and thus the two quasi-
physical model components, with physical features of the drainage area.
72-73:02F-022
UNCONFINED FLOW THROUGH JOINTED ROCK,
Castillo, E., Karadi, G.M., and Krizek, R. J.
Water Resources Bulletin, Vol. 8, No. 2, p 266-281, April 1972. 13 fig, 1 tab,
9 ref.
Descriptors: *Groundwater movement, *Joints (Geologic), Fractures (Geologic),
*Mathematical models, *Numerical analysis. Laminar flow, Turbulent flow, Per-
meability, Viscosity, Density, Roughness (Hydraulic).
The two-dimensional, steady-state, unconfined flow of a homogeneous fluid
through jointed rock was studied for both laminar and turbulent conditions by
use of a method which is based on theoretical and experimental flow relation-
ships. Only the independent unknowns are computed in order to reduce the
complexity of the problem and render it more readily tractable. The intact
rock is assumed to be impermeable, and two intersecting systems of plane,
parallel joints are responsible for all permeability in the mathematical
model, taking into account the surface roughness of the joints. The mathe-
matical solution of the resulting nonlinear system of equations is obtained by
use of a rapidly converging iterative procedure, in which each iteration takes
special advantage of the banded nature of the associated matrix. For the
particular case in which a free surface exists, the general flow equations
are not satisfied, because some of the joints in the vicinity of the free sur-
face do not flow full; therefore, new equations must be established to handle
this condition. Once the development of the mathematical model is accomplished,
several cases involving different geometric characteristics (width, orientation,
and roughness of joints) are solved for a rectangular domain, and graphs
are given to illustrate the influence of the various parameters on the mani-
fested flow behavior.
72-73:02F-023
DEEP PERCOLATION IN A SAND HILL AREA,
Glover, R. E.
Colorado State University, Fort Collins, Department of Civil Engineering.
Water Resources Bulletin, Vol. 8, No. 2, p 399-400, April 1972. 6 ref.
Descriptors: *Percolation, *Recharge, *Infiltration, *Water balance, *Sur-
face-groundwater relationships, Nebraska, Great Plains, Water yield, Sands.
Identifiers: *Sand Hills (Nebraska), Ogallala Formation.
Infiltration into the Ogallala aquifer in Nebraska was calculated using records
for two rivers flowing in a Sand Hill area. The infiltration is 0.23 feet per
year, which is 13% of the precipitation. Weather Bureau records for Halsey
based on 58 years of observation yield an average precipitation rate of 20.73
inches per year or 1.727 feet per year. In this area the deep percolation
represents 0.134 of the precipitation.
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72-73:02F-024
ROLE OF SUBSURFACE FLOW IN GENERATING SURFACE RUNOFF. 2. UPSTREAM SOURCE
AREAS,
Freeze, R. A.
Thomas J. Watson Research Center, Yorktown Heights, New York.
Water Resources Research, Vol. 8, No. 5, p 1272-1283, October, 1972. 11 fig,
27 ref.
(See 72-73:02A-002)
72-73:02F-025
IDENTIFICATION OF PARAMETERS IN FINITE LEAKY AQUIFER SYSTEM,
Marine, M. A. and Yeh, W. W. G.
California University, Los Angelos, Department of Engineering Systems.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
99, No. HY2, paper 9567, p 319-336, February 1973. 5 fig, 5 tab, 15 ref,
append.
Descriptors: *Artesian aquifers, *Finite element analysis, *Numerical analysis,
Transmissivity, Storage coefficient, Parametric hydrology, Systems analysis,
Aquifer characteristics, Groundwater movement, Leakage.
Identifiers: *Leaky aquifers.
Many methods for analyzing leaky artesian systems are graphical procedures
which involve invlection-point estimation and extrapolation of field data,
or superposition and matching, or both, of field data to a family of theoretical
curves. A systematic procedure for the identification of aquifer parameters
in a finite leaky artesian system converts field observations directly to
system parameters. The parameters to be identified are the transmissivity and
storativity of the main aquifer, and the leakage factor of the system. The
algorithm involves finite difference approximation and quasilinearization in
conjunction with least-squares optimization. Examples that demonstrate the
applicability of the algorithm are presented.
72-73:02F-026
DISPERSION IN NONUNIFORM SEEPAGE,
Hunt, B. W.
Canterbury University, Christchurch (New Zealand), Department of Civil Engi-
neering.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
99, No. HY2f Paper 9553, p 295-299, February 1973. 7 ref, append.
Descriptors: *Dispersion, *Seepage, *Non-Uniform flow, *Groundwater movement,
*Path of pollutants, Mixing, Mathematical models, Equations, Numerical analysis.
General equations are derived which describe the dispersion of a pollutant in
three-dimensional, nonuniform seepage. These equations are obtained by assuming
that the principal directions of the dispersion tensor are tangential and normal
to the streamlines, and the final result is shown to agree with the results
of previous investigators only when the principal values of the dispersion
tensor are written in a form which, in general, may not agree with experimental
results. The advantages of using this model to compute numerically the con-
centrations of a pollutant from piezometric head field data are pointed out.
40
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72-73:02F-027
GRAVITATIONAL AND DISPERSIVE MIXING IN AQUIFERS,
Gelhar, L. W., Wilson, J. L., and Miller, J. S.
Massachusetts Institute of Technology, Cambridge, Department of Civil Engineer-
ing.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
98, No. HY12, Paper 9439, p 2135-2153, December 1972. 7 fig, 2 tab, 12 ref,
append.
Descriptors: *Mixing, *Artificial recharge, *Dispersion, *Recharge wells. Path
of pollutants, Injection wells, Stratified flow, Water quality, Density strati-
fication, Convection, Groundwater movement, Hydraulics, Water storage.
Analytical techniques were developed to describe the mixing between two fluids
of different density in a confined aquifer, in which one fluid is introduced
to the aquifer by well recharge. The immiscible displacement process in radial
flows was analyzed. The effects of longitudinal and lateral dispersion are
included using a boundary layer approximation. The theoretical results were
compared with observations of aquifer mixing in a laboratory model. Excellent
agreement between the theoretical predictions and experimental results was
found. Theoretical predictions of recovery efficiency during a recharge-
storage-withdrawal cycle show trends similar to those observed, but are some-
what lower. Direct theoretical predictions of recovery efficiency were develop-
ed for an immiscible system.
72-73:02F-028
STEADY SEEPAGE FLOW TO SINK PAIRS SYMMETRICALLY SITUATED ABOVE AND BELOW A
HORIZONTAL DIFFUSING INTERFACE: 1. PARALLEL LINE SINKS,
Wolanski, E. J., and Wooding, R. A.
Johns Hopkins University, Baltimore, Maryland, Department of Environmental
Engineering.
Water Resources Research, Vol. 9, No. 2, p 415-425, April 1973. 7 fig, 16 ref.
Descriptors: *Saline water-freshwater interfaces, *Diffusion, *Groundwater
movement, *Saline water intrusion, Dispersion, Encroachment, Withdrawal,
Steady flow. Saturated flow. Safe yield. Boundary layers.
The flow regime close to a pair of wells situated on opposite sides of a
diffusing interface between freshwater overlying saline water is illustrated
using an idealized symmetrical system. The interface is horizontal, and
gravitational effects are neglected. A uniform flow is parallel to the inter-
face, and the fresh and saline fluids are separated by a thin impermeable
layer at a finite distance upstream from the sinks. The edge of the impermeable
layer provides a definite starting point for diffusive mixing at the interface.
As part of a largescale gravity system, flow in the upper fluid should bear a
qualitative resemblance to real situations where freshwater is moving slowly
over nearly stationary saltwater. Boundary layer theory is used to treat the
growth of the diffusive mixing layer, modified by the presence of the sinks.
The flux of salt to the upper sink is calculated as a function of the spacing
and strength of the uniform flow. A periodic system of sink pairs without an
applied flow is also considered. Exact solutions of the boundary layer equa-
tions are readily obtained for the two-dimensional case.
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72-73:02F-029
UNSTEADY FLOW TO A PARTIALLY PENETRATING, FINITE RADIUS WELL IN AN UNCONFINED
AQUIFER,
Kipp, K. L. Jr.
Washington University, Seattle.
Water Resources Research, Vol. 9, No. 2, p 448-462, April 1973. 8 fig, 18 ref.
Descriptors: *Unsteady flow, *Groundwater movement, *Equations, *Water yield,
*Drawdown, Saturated flow, Mathematical studies, Numerical analysis. Water
wells, Hydraulic conductivity. Aquifer testing, Hydrogeology.
Identifiers: *Partially penetrating wells.
Unsteady flow to a single, partially penetrating well of finite radius in an
unconfined aquifer is solved theoretically. The aquifer is homogeneous,
isotropic, and infinite both in thickness and lateral extent. Perturbation
expansion techniques linearize the free surface boundary conditions, so
that the solution satisfies the boundary conditions through first order pro-
vided that the drawdowns remain small, and that a time limit is imposed.
The basic potential field is created by distributing dipole moments over the
surface of the well bore and solving the resulting integral equation numerically.
The solution can be used to model pumped well behavior for the initial period
after the start of pumping. This solution is not restricted to the constant
flow rate or constant head modes of simulation. The assumption of constant
discharge operation in earlier, more approximate solutions to this problem is
more realistic than the assumption of constant head operation.
72-73:02F-030
MASS TRANSPORT IN FLOWING GROUNDWATER,
Bredehoeft, J. D., and Pinder, G. F.
Geological Survey, Lakewood, Colorado
Water Resources Research, Vol. 9, No. 1, p 194-210, February 1973. 20 fig,
18 ref.
Descriptors: *Path of pollutants, *Artesian aquifers, *Georgia, *Groundwater
movement, *Saline water intrusion. Encroachment, Mathematical models, Mass
transfer, Saline water, Withdrawal, Hydrologic budget.
Identifiers: *Brunswick (Georgia).
The mass transport equation and the equation of motion were coupled and solved
numerically for a saturated isothermal groundwater system in which there are
no chemical reactions. A case history of groundwater contamination at Bruns-
wick, Georgia, illustrates the use of this physical-chemical model in predicting
and controlling the future movement of contaminants. The principal artesian
aquifer in the Brunswick area is composed of permeable zones in the Oca la and
underlying limestones of Clairborne age. At least three more or less isolated
zones are recognized. The permeable zones are separated from one another by
dense limestones. The units that act as aquifers are highly permeable; caverns
have been detected in each. Both the upper and lower water-bearing zones show
areas of saltwater contamination. The source of the water is the underlying
brackish water zone, the water migrating upward through two natural conduits.
These conduits may be associated with a fault. The most feasible measure to
protect the well field is to put interceptive pumping in the aquifer between
the source of contamination and the pumping center.
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72-73:02F-031
EFFECT OF NONLINEAR STABILIZING SALINITY PROFILES ON THERMAL CONVECTION IN A
POROUS MEDIUM LAYER,
Rubin, H.
Technion - Israel Institute of Technology, Haifa, Department of Civil Engineer-
ing.
Water Resources Research, Vol. 9, No. 1, p 211-221, February 1973. 5 fig, 2 tab,
9 ref.
Descriptors: *Convection, *Path of pollutants, *Saline water intrusion,
*Porous media, Mixing, *Dispersion, Groundwater movement, Density stratification.
Aquifers, Stratified flow, Mass transfer, *Salinity.
Nonlinear salinity profiles may exist in an aquifer when salt water and fresh
water are brought into contact. They may be maintained indefinitely by a
horizontal flow. The effect of such salinity profiles on marginal stability
and overstability, as well as on thermal convection, was investigated. Non-
linearity of the salinity profile affects the stability criteria of the field
and changes the shape of the convective cells appearing at instability.
Nonlinearity of the profiles may increase the stability more than in the linear
case for small values of the Rayleigh number.
72-73:02F-032
FUNCTIONAL COEFFICIENTS IN THE ANALYSIS OF GROUNDWATER FLOW,
Finder, G. F., Frind, E. O., and Papadopulos, S. S.
Princeton University, New Jersey, Department of Civil and Geological Engineer
ing.
Water Resources Research, Vol 9, No. 1, p 222-226, February 1973. 3 fig,
3 ref.
Descriptors: *Groundwater movement, *Finite element analysis, *Mathematical
studies, Variability, Numerical analysis, Porous media.
Identifiers: Galerkin theory.
Although finite element techniques in groundwater flow analyses generally
require constant aquifer parameters over each element, variable properties can
be handled easily by using isoparametric quadrilateral elements in conjunction
with approximating equations generated by using Galerkin's technique. A steady
state radial flow problem in which transmissivity varies as a linear function
of the radius from the well indicates that the, accuracy of the numerical
scheme may be improved considerably through the use of functional aquifer
coefficients. Whenever a system is characterized by sharp changes in permea-
bility or some other parameter, such as those changes that often appear in
geologic cross sections, the use of a constant parameter over an element may
be advantageous. In the finite element formulation, integration is carried
out over each element independently, and a computer code capable of mixing
constant and functional coefficients in the same problem is easily generated.
72-73:02F-033
NONLINEAR EQUATION OF UNSTEADY GROUNDWATER FLOW,
Bruch, J. C. Jr.
California University, Santa Barbara, Department of Mechanical Engineering.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
99, No. HY3, Paper 9589, p 395-403, March 1973, 5 fig, 7 ref, append.
43
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Descriptors: *Groundwater movement, *Finite element analysis, *Unsteady flow,
Water table, Surface-groundwater relationships, Numerical analysis. :
Unsteady groundwater movement may be described using a finite element weighted
residual process to solve nonlinear partial differential equations. The ground-
water in an unconfined aquifer may flow either into or out of a surface reser-
voir. Rectangular, as well as triangular, finite elements were used in a
space-time solution domain. The weighting function was equal to the
shape function defining the dependent variable approximation. The results
were compared in dimensionless graphs with experimental as well as other
numerical data. The finite element method compared favorably with these
results and was easily programmed, stable, computationally fast, rapidly
convergent, and does not require constant parameters over the entire solution
domain.
72-73:02F-034
EXPERIMENTAL AND MATHEMATICAL MODELING OP LIQUID-LIQUID MISCIBLE DISPLACEMENT
IN POROUS MEDIA,
Chhatwai, S. S., Cox, R. L., Green, D. W., and Ghandi, B.
Kansas University, Lawrence, Department of Chemical and Petroleum Engineering.
Water Resources Research, Vol. 9, No. 5, p 1369-1377, October 1973. 10 fig,
1 tab, 13 ref.
Descriptorsj *Dispersion, *Mixing, *Groundwater movement. Saline water intru-
sion, Path of pollutants, Diffusion, Numerical analysis. Convection, Mathe-
matical models. Hydraulic models.
When one liquid in a porous medium displaces a second miscible liquid of
different density, both gravity effects and dispersion are present at the
liquid-liquid interface. Equations describing this process were solved
numerically. The method of characteristics numerical solution and a new
technique (the centered in distance, centered in time method) were evaluated
by direct comparison and by checking against an analytical solution for the
case of one-dimensional flow. The solutions were used to simulate saltwater
displacement experiments in a two-dimensional laboratory model as a further
test.
72-73:02F-035
ANALYTICAL SOLUTIONS TO THE ONE-DIMENSIONAL NONLINEAR DIFFUSION EQUATION FOR
FLOW THROUGH POROUS MEDIA,
Moench, A. F.
Geological Survey, Denver, Colorado.
Water Resources Research, Vol. 9, No. 5, p 1378-1384, October 1973. 4 fig,
3 tab, 4 ref.
Descriptors: *Diffusion, *Groundwater movement, *Numerical analysis, *Porous
media, Transmissivity, Equations, Mathematical studies, Soil water movement.
Saturated flow, Unsaturated flow.
The one-dimensional nonlinear diffusion equation was solved approximately by
an extension of the Neumann method for a step input to a semi-infinite medium.
The method of solution requires that the region under consideration be divided
into an arbitrary number of zones, each zone having known constant diffusivit-
ies. The boundaries between zones move at rates that are initially unknown.
Two problems were considered: (1) horizontal flow in an aquifer in which the
44
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transmissivity and storage coefficients are functions of hydraulic head and
(2) horizontal absorption in an unsaturated soil for which the diffusivity is
a funtion of moisture content. Computational results compare well with finite
difference and other numerical solutions to the same problems. The technique
has application to other nonlinear problems of the same type.
72-73J02F-036
EQUATION FOR ONE-DIMENSIONAL VERTICAL FLOW OF GROUNDWATER: 2. VALIDITY RANGE
OF THE DIFFUSION EQUATION,
Gambolati, G.
Centre di Ricerca IBM di Venezia (Italy).
Water Resources Research, Vol. 9, No. 5, p 1385-1395, October 1973. 14 fig,
8 ref.
Descriptors: *Groundwater movement, Consolidation, *Compaction, Land subsi-
dence. Subsidence, Deformation, Diffusion, Equations, Aquifer testing, Porous
media, Dispersion, Mathematical studies.
The reliability of the parabolic diffusion equation was investigated by solving
the rigorous one-dimensional equation of groundwater flow in deforming soils.
The dependence of the hydraulic conductivity on the specific weight of water
is included. The grain velocity was expanded first. This expansion leads
to a nonlinear integro-differential term. An iterative finite element techni-
que of solution was then developed. .The true time-dependent pressure head was
compared to the standard one. The entire range of variations for the formation
parameters was carefully explored. The usual equation gives satisfactory re-
sults in the vast majority of applications. The conditions underlying the
approximated theory become critical only when the flow field is to be deter-
mined in highly compressible units for strong boundary pressure variations.
In this case the solid material movements can no longer be considered small.
The pressure head changes are faster than it would appear from the
standard solution, and the consolidation process is more rapid than that in the
classical Terzaghi's theory.
72-73:02F-037
GALERKEN SOLUTION OF THE INVERSE PROBLEM FOR AQUIFER TRANSMISSIVITY,
Frind, E. O.f and Pinder, G. F.
Waterloo University (Ontario), Department of Earth Sciences.
Water Resources Research, Vol. 9, No. 5, p 1397-1410, October 1973. 11 fig,
20 ref.
Descriptors: *Groundwater movement, *Aquifer testing, *Transmissivity, *Finite
element analysis, Numerical analysis, Equations, Mathematical models, Flow nets.
Identifiers: *Galerkin method.
The inverse problem in aquifer analysis may be solved by a Galerkin finite
element approach. The proposed solution was applied to an inhomogeneous
isotropic aquifer for which steady state piezometric head is known and trans-
missivity is unknown. The condition for existence and uniqueness of a solution
is that transmissivity must be known along a line crossed by all streamlines in
the flow system. In the Galerkin solution this condition may be stated alter-
natively in terms of flux, so that knowing the discharge at a well may satisfy
the uniqueness requirement. Isoparametric finite elements were used; polynomial
shape functions approximated aquifer geometry, hydraulic head, and transmissiv-
ity. The flexibility of the isoparametric elements permits using an irregular
45
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grid with nodes directly at observation points. The solution is highly
sensitive to the degree of approximation in the functional representation of
hydraulic head but relatively insensitive to the representation of transmissiv-
ity. The finite element solution converges to a unique solution as element
size decreases.
72-73:02F-038
TIME SERIES ANALYSIS OF THE HYDROLOGIC REGIMEN OF A GROUNDWATER DISCHARGE AREA,
Jackson, R. E., Gilliland, J. A., and Adamowski, K.
Ottawa University (Ontario), Department of Civil Engineering.
Water Resources Research, Vol. 9, No. 5, p 1411-1419, October 1973. 4 fig,
18 ref.
Descriptors: *Time series analysis, *Groundwater, *Discharge (Water), *Water
level fluctuations, Hydrogeology, Variability, Markov processes, Evapotranspora-
tion, Statistics, Precipitation (Atmospheric), Climates, Water balance, Hydro-
graph analysis, *Canada.
Time series analysis was employed to examine climatological and hydrogeological
variables associated with a groundwater discharge area in Manitoba, Canada.
Daily groundwater evapotranspiration and inflow rate were adequately modeled
by a first-order Markov process. Nonrandom fluctuations association with
the weather and circulation of the North American summer climate were identified
in the time series of mean daily temperature and groundwater evapotransporation?
daily precipitation was random. Statistical filtering of the hydrogeological
time series showed that two processes were associated with seasonal maximums in
the groundwater evapotranspiration series, one due to the propagation of
groundwater recharge through the flow system and the other due to climatic
effects on the discharge area, in particular, the Lisse effect.
72-73:02F-039
FRICTION FACTOR AND REYNOLDS NUMBER IN POROUS MEDIA FLOW,
Arbhabhirama, A., and Dinoy, A. A.
Asian Institute of Technology, Bangkok (Thailand), Division of Water Science
and Engineering.
Journal of the Hydraulics Division, American Society of Civil Engineers,
Vol. 99, No. HY6, Paper 9784, p 901-911, June 1973. 6 fig, 2 tab, 10 ref,
append.
Descriptors: *Porous media, *Fluid friction, *Reynolds number, *Groundwater
movement, *Hydraulic radius, Pores, Porosity, Fluid mechanics, Permeability,
Hydraulic conductivity.
The concept of hydraulic radius of pore spaces is used to show that the square
root of the permeability is the important length parameter in defining the
friction factor aid Reynolds number in flow through porous media. Hydraulic
radius is defined by the Kozeny-Carman theory of hydraulic radius of pore
space. Various porous media had different relationships between friction factor
and Reynolds number. Experimental results showed a similarity to the Moody
diagram used for pipe flow, with the ratio of particle mean diameter to the
mean hydraulic radius of pore spaces as the third parameter.
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72-73:02F-040
BEHAVIOR OF GROUNDWATER FLOW SUBJECT TO TIME-VARYING RECHARGE,
Tseng, M. T., and Ragan, R. M.
Water Resources Engineers, Inc., Springfield, Virginia.
Water Resources Research, Vol. 9, No. 3, p 734-742, June 1973. 12 fig, 9 ref.
Descriptors: *Groundwater movement, *Recharge, *Equations, *Numerical analysis,
Hydraulic models, Water table, Simulation analysis, Mathematical models.
Identifiers: Hele-Shaw models.
The dynamic response of two-dimensional unconfined aquifers subject to localized
recharge was studied theoretically. The variations of free surface profiles,
discharges, and the flow patters with respect to time in both fully penetrated
and partially penetrated aquifer systems are obtained by solving the governing
partial differential equations numerically. The method treats the nonlinear
free surface boundary as an initial condition, and the overall flow region is
solved as a boundary value problem. The numerical results agree with experi-
mental data obtained from Hele-Shaw models. The method may be applied to study
the quantitative andB qualitative changes in groundwater reservoirs resulting
from artificial or natural recharge.
72-73:02F-041
MASS BALANCE AND SPECTRAL ANALYSIS APPLIED TO KARST HYDROLOGIC NETWORKS,
Brown, M. C.
Alberta University, Edmonton, Department of Geography
Water Resources Research, Vol. 9, No. 3, p 749-752, June 1973. 4 fig, 8 ref.
Descriptors: *Water balance, *Karst hydrology, *Statistical methods, Varia-
bility, Tracers, Hydrologic budget, Caves, Subsurface flow, Fourier analysis,
Frequency analysis, Input-output analysis.
Identifiers: Spectral analysis.
Underground karst drainage systems can be studied by the input-output relations
of rivers that flow through them. Tracers enable the quantity of water at a
sink that flows to a specific spring, and the fraction of a given spring
derived from a sink, to be calculated. When tracer methods are not applicable,
cross-covariance and cross-spectral transfer functicna analysis can be used to
examine input-output stage records. These give information about the vadose
and/or phreatic nature of the system. An inaccessible karst drainage system
in western Alberta has a tracer flow-through time of 80 to 130 hours and a
positively skewed cross covariance of 70 to 124 hours? therefore the cave
is not completely water filled. Additional unknown inputs are substantiated
by a negatively peaking cross covariance.
72-73:02F-042
THE ENVIRONMENTAL TRITIUM CONCENTRATION OF UNDERGROUND WATER AND ITS HYDRO-
LOGICAL INTERPRETATION,
Allison, G. B., and Holmes, J. W.
Commonwealth Scientific and Industrial Research Organization, Glen Osmond
(Australia), Division of Soils
Journal of Hydrology, Vol. 19, No. 2, p 131-143, June 1973. 5 fig, 3 tab,
23 ref.
Descriptors: *Tritium, *Groundwater movement, *Water balance, Recharge,
Discharge (Water), Tracers, Mixing, Springs, Australia, Model studies.
47
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Models which attempt to correlate the tritium concentration of water taken
from aquifers to aquifer parameters are discussed. One model takes into
account flow along individual streamlines and relates aquifer parameters to the
observed tritium concentration at outflow. For the Gambier Plain unconfined
aquifer in southern Australia, the calculated tritium concentration at outflow
derived from known aquifer parameters is 0.7 T.U. The measured tritium concen-
tration of several springs at outflow is also 0.7 T.U. Using the complete
mixing model and the approximation that samples withdrawn from the aquifer on
Eyre Peninsula, South Australia, are fully mixed, the mean annual recharge
for the area is estimated at 3 cm/yr.
72-73:02F-043
COMPARISON OF RECHARGE TO GROUNDWATER UNDER PASTURE AND FOREST USING ENVIRON-
MENTAL TRITIUM,
Allison, G. B., and Hughes, M. W.
Commonwealth Scientific and Industrial Research Organization, Adelaide (Austra-
lia) , Division of Soils.
Journal of Hydrology, Vol. 17, No. 1-2, p 81-95, October 1972. 3 fig, 2 tab,
20 ref.
Descriptors: *Water balance, *Evapotranspiration, *Infiltration, *Recharge,
*Tracers, Tritium, Vegetation effects, *Australia, Pine trees, Soil water,
Soil moisture, Sampling.
Recharge to groundwater under pasture and forest at a site on the Gambier Plain,
southern Australia, was investigated by using environmental tritium as a tracer.
Water from the top 20 cm of the shallow unconfined aquifer was sampled at
locations both in pasture and forest during October 1970 and February 1971.
For several sites along a groundwater streamline, the mean tritium concentra-
tion of groundwater beneath the forest was 1.8 TU, while that under pasture
was 12 TU. The mean depths to water were approximately the same for both land
covers, being 6.0 m and 5.6 m, respectively. The conclusion is that there is
virtually no recharge to groundwater beneath the forest, which contradicts the
results of a study of water level fluctuations in the Karstic aquifer of the
area.
72-73:02F-044
AN ATTEMPT AT ESTIMATING THE TRANSMISSIBILITIES OF TRAPPEAN AQUIFERS FROM
SPECIFIC CAPACITY VALUES,
Adyalkar, P. G., and Mani, V. V. S.
Central Groundwater Board, Nagpur (India).
Journal of Hydrology, Vol. 17, No. 3, p 237-241, November 1972. 2 tab, 9 ref.
Descriptors: *Transmissivity, *Specific capacity, *Hydrogeology, *Groundwater
movement, *Thiems equation, Basalts, Aquifer characteristics. Water yield,
Drawdown, Aquifer testing.
Identifiers: *India.
Based on Thiem's equilibrium formula, an attempt is made to arrive at an
empirical factor for the determination of transmissibility. Multiplying the
factor by the specific capacity values of the wells tested gives an average
value for T for unconfined water-table aquifer conditions in basalt terrains.
The suitability of this method with particular reference to poorly permeable
water-table aquifers in Maharashtra in India is discussed.
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72-73:02F-045
PERTURBATION ANALYSIS OF THE EQUATION FOR THE TRANSPORT OF DISSOLVED SOLIDS
THROUGH POROUS MEDIA, PART III, INFLUENCE OF BOUNDARY CONDITIONS,
Wooding, R. A.
Wisconsin University, Madison, Department of Soil Science.
Journal of Hydrology, Vol. 16, No. 3, p 241-245, July 1972. 1 fig, 5 ref.
Descriptors: *Porous media, *Mass transfer, *Diffusion, *Chemical reactions,
*Ion transport, Dispersion, Water chemistry, Permeameters, Chromatography,
Solutes, Aqueous solutions.
The properties of solute transport involving firstorder irreversible reaction
in a finite column of porous material with unstirred fluid both upstream and
downstream are described in a linearized system. If the effective diffusivity
in the column is large compared with that in the unstirred fluid, the Danckwerts
boundary conditions are appropriate. This situation is typically found in
laboratory columns and chemical reactors. At the upstream boundary a pseudo-
discontinuity in concentration exists, and depends upon the reaction rate and
the rate of fluctuation of the input concentration. (The influence of down-
stream boundary conditions is exponentially small, and is neglected). At the
downstream boundary, a small 'back-diffusion1 zone exists, and serves to adjust
the outlet concentration gradient to zero.
72-73:02F-046
A NEW TECHNIQUE FOR TIME-VARIANT GROUND WATER FLOW ANALYSIS,
Herbert, R., and Zytynski, M.
Journal of Hydrology, Vol. 16, No. 2, p 77-92, June 1972. 13 fig, 6 ref.
Descriptors: *Groundwater movement, *Water level fluctuations, *Drawdown,
*Simulation analysis. Drainage effects, Drainage systems. Mathematical models,
Seepage, Withdrawal, Permeability, Numerical analysis, Computer programs.
A new numerical method is described which accurately simulates the time-
variant movement of the water table in unconfined saturated strata. The method
is suitable for use on a digital computer and requires far less storage space
and computing time than alternative more complex techniques in regular present
day use. The new technique is tested against well-proven alternative methods
and proves to be accurate and convenient to use. The new technique is parti-
cularly suited to the analysis of the performance of groundwater lowering
systems and a suite of programs has been developed based on the new method
which has been successfully used as a design aid to many groundwater lowering
schemes.
72-73:02F-047
PERTURBATION ANALYSIS OF THE EQUATION FOR THE TRANSPORT OF DISSOLVED SOLIDS
THROUGH POROUS MEDIA: II. BASIC NON-LINEAR PROBLEM,
Wooding, R. A.
Wisconsin University, Madison, Department of Soil Science
Journal of Hydrology, Vol. 16, No. 2, p 105-116, June 1972. 3 fig, 7 ref.
Descriptors: *Groundwater movement, *Mass transfer, *Ion transport, *Diffusion,
*Mathematical studies, Translocation, Ion exchange, Equilibrium, Leaching,
Chemical precipitation. Porous media, Adsorption.
Singular perturbation methods are used to treat analytically the problem of
49
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steady one-dimensional flow in a porous column, assuming nonlinear exchange
equilibrium and concentration-dependent diffusivity, when the Peclet numer is
large. The breakdown of the original problem into a nonlinear outer problem,
which is hyperbolic and of first order, and an inner problem which is equiva-
lent to a set of ordinary differential equations, greatly facilitates analysis.
The development and movement of concentration discontinuities within the flow
is examined via the outer expansion, the first term of which neglects diffusion
entirely. The next term gives a first estimate of diffusion effects. Material
diffusing towards a discontinuity increases its speed. In the neighborhood of
a discontinuity, a state of quasi-equilibrium exists between diffusion and
convective effects due to the relative velocity between the characteristics
and the discontinuity. The first term of the inner expansion is matched both
ahead of and behind the jump with the aid of only one arbitrary function of
integration; the second function remains undetermined. At the next order,
this function is evaluated as a shift of origin of the inner expansion to match
the displacement of the jump due to diffusion. However, at this next order of
matching, a new undetermined function appears. Extensions of the method to
more general cases of nonlinear, nonequilibrium exchange, and when source
terms are present, are discussed briefly.
72-73:02F-048
UNCONFINED AQUIFER AND SLOW DRAINAGE,
Streltsova, T. D.
Birmingham University (England), Department of Civil Engineering.
Journal of Hydrology, Vol. 16, No. 2, p 117-134, June 1972. 6 ref.
Descriptors: *Groundwater movement, *Drawdown, *Water level fluctuations,
*Theis equation. Storage coefficient. Water yield, Unsteady flow, Unsaturated
flow, Hydrogeology.
Identifiers: *Unconfined aquifers.
One of the features of unsteady free surface flow is the phenomenon of slow
draining of water-bearing materials. This phenomenon is usually identified and
referred to as delayed yield from storage. By this is understood the slowing
of the rate of lowering of the piezometric surface during the early period of
pumping for the unsteady radial flow to a pumped well compared to the well-
known nonequilibrium Theis theory. However, consideration of the nature of this
phenomenon may show an identification to be inexpedient. The slow drainage
observed in practice may also be considered as a delayed process of vertical
transfer; there is no delayed yield.
72-73:02F-049
THE APPLICATION OF THE AUGER HOLE METHOD IN HOLDERNESS GLACIAL DRIFT,
Bone11, M.
Hull University (England), Department of Geography.
Journal of Hydrology, Vol. 16, No. 2, p 125-146, June 1972. 4 fig, 3 tab,
27 ref.
Descriptors: *Hydraulic conductivity, *Glacial drift, *Groundwater movement,
*Aquifer testing, Water yield, Boreholes, Piezometers, Withdrawal, Hydrogeology.
Identifiers: England.
The auger hole method was applied in Holderness glacial drift, England, to
determine variations in hydraulic conductivity in the context of a shallow
groundwater investigation in a small experimental catchment. The computational
methods employed and some details of the practical problems encountered in
50
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field measurement are discussed. The results are used in the interpretation of
hydrogeological, well hydrograph and drainage phenomena associated with the
drift material. The calculated hydraulic conductivity values derived from the
Kirkham and Van Bavel and Ernst formulae are compared. The Ernst approximate
formula is sufficiently accurate for determination of conductivity within the
limited range of pumping test geometries dealt with.
72-73:02F-050
NONSTEADY FLOW IN A RECHARGE WELL-ONCONFINED AQUIFER SYSTEM,
Marino, M. A., and Yeh, W. W. G.
California University, Los Angelos.
Journal of Hydrology, Vol. 16, No. 2, p 159-176, June 1972. 9 fig, 1 tab,
21 ref.
Descriptors: *Unsteady flow, *Injection wells, *Groundwater movement, *Mathe-
matical studies, *Recharge wells, Dupuit-Forchheimer theory, Hydrogeology,
Hydraulic conductivity, Artificial recharge, Numerical analysis, Model studies,
Mathematical models, Dimensional analysis.
A recharge well-unconfined aquifer system is considered in which the well
completely penetrates a homogeneous, isotropic, extensive aquifer. The
system is characterized also by nonuniformity of the recharge rate, constancy
of the injection head, hydraulic conductivity, and specific yield of the
aquifer, and the validity of the Dupuit-Forchheimer assumptions. Dimensional
analysis and similarity approximation are used to transform the governing second-
order, nonlinear, partial differential equation into a second-order, nonlinear,
ordinary differential equation. The differential equation is solved by coupling
the fourth-order Runge-Kutta method with the Lagrange interpolation method.
The method is inherently stable for any times. Dimensionless graphical solu-
tions of water table profiles at different times are presented for various
conditions. A closed-form analytical solution based on the linearized equa-
tion is developed that closely approximates the flow system under consideration.
Dimensionless graphical solutions for volume and average rate of recharge are
presented for conditions commonly encountered in practice. The dimensionless
form of the solutions makes possible their application to any well-aquifer
system with similar characteristics regardless of the values of the hydraulic
properties of the aquifer.
72-73:02F-051
STATISTICAL PROCESSING OF LONG-TERM OBSERVATIONS OF GROUNDWATERS,
Kriz, H.
Ceskoslovenska Akademie Ved, Brno. Geograficky Ustav.
Journal of Hydrology, Vol. 16, No. 1, p 17-37, May 1972. 7 fig, 9 tab, 4 ref.
Descriptors: *Water level fluctuations, *Groundwater, *Data processing,
*Statistical methods, Statistics, Water well, Water balance. Data collections,
Hydrologic data.
Identifiers: "Czechoslovakia.
The processing of the seventy-year series (1901-1970) of weekly groundwater
levels from observation well No. 12 in the Bohemian Cretaceous Plateau in
Moravia illustrates the statistical methods used in Czechoslovakia. The so-
called characteristic levels were derived from the weekly groundwater levels
for the years 1901-1970. These are groundwater levels that, on the average,
are exceeded for a certain number of days in the year and often reported also
as a percentage of the total duration of observation. Further characteristics
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are the average monthly and annual groundwater levels, calculated as arithmetic
means from the weekly levels recorded in'the individual hydrological years,
from which, in turn, the average values for the entire period under study were
established. The highest and the lowest annual values were established in
addition, as well as the absolute extreme levels for the entire period of
1901-1970. Based on the average annual groundwater levels, the hydrological
years 1901-1970 were classified from the viewpoint of their yield rates.
Long-term changes in the groundwater storages were studied from the plot
of the course of weekly hydrographs. A detailed analysis of the groundwater
level variations showed that the change in the storages proceeded, in general,
in a regular rhythm.
72-73:02F-052
THE INFLUENCE OF DELAYED DRAINAGE ON DATA FROM PUMPING TESTS IN UNCONFINED
AQUIFERS,
Boulton, N. S.
Sheffield University (England), Department of Civil and Structural Engineering.
Journal of Hydrology, Vol. 19, No. 2, p 157-169, June 1973. 2 fig, 9 ref.
Descriptors: *Aquifer testing, *Drawdown, *Water yield, Aquitards, Permeability,
Hydrogeology, Anisotropy, Equations.
Identifiers: Delayed yield.
Equations are given for the flow to a pumped well in an aquifer having uniform
anisotropy and overlain by a low-permeability aquitard. The water table is
assumed to be located in the aquitard. Drainage from the capillary zone
above the water table is taken into account. The formation constants may be
evaluated by using type curves. A well-known pumping test is reanalyzed, using
the given equations. The time-drawdown curves can be explained only by the
existence of a low-permeability stratum in the vicinity of the water table.
In this example the slow draining of the unsaturated zone above the water table
seems to be a significant factor in determining the shape of the time-drawdown
curves.
72-73:02F-053
WATER-TABLE FLUCTUATION IN SEMIPERVIOUS STREAM-UNCONFINED AQUIFER SYSTEMS,
Marino, M. A.
California University, Davis.
Journal of Hydrology, Vol. 19, No. 1, p 43-52, May 1973. 4 fig, 7 ref.
Descriptors: *Surface-groundwater relationships, *Water level fluctuations.
Recharge, Infiltration, Alluvial channels, Permeability, Drawdown, Equations.
.Available expressions which describe the watertable fluctuation in a stream-
aquifer system are based primarily on the assumption that the bed of the
stream is as permeable as the aquifer it completely cuts through. New analyti-
cal expressions were developed, in terms of the head averaged over the depth
of saturation, to take into account the semiperviousness of the streambed.
The situations considered the finite and semi-infinite aquifer systems in which
the water level in the semipervious stream is suddenly lowered below its
initial elevation, and suddenly raised above its initial elevation, and main-
tained constant thereafter. As a by-product, solutions are also obtained for
finite and semi-finite aquifer systems in which the bed of the stream is as
permeable as the aquifer.
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72-73:02F-054
ANALYTIC SOLUTION OP SPATIALLY DISCRETIZED GROUNDWATER FLOW EQUATIONS,
Kuiper, L. K.
Geological Survey, Iowa City, Iowa.
Water Resources Research, Vol. 9, No. 4, p 1094-1097, August 1973. 1 fig,
4 ref.
Descriptors: *Mathematical studies, *Groundwater movement, Numerical analysis,
Finite element analysis.
The Galerkin procedure, when it is applied to the equation for horizontal two-
dimensional flow of groundwater in a nonhomogeneous isotropic aquifer, gener-
ates approximating equations involving square matrices and column matrices.
An analytic solution to the matrix equation is given. These methods are
compared with the approximate numerical Crank-Nicholson procedure by applying
both to a particular problem for which the unknown column matrix has 49 ele-
ments. The Crank-Nicholson procedure usually requires less computation time
for the confined aquifer case but gives errors for drawdown averaging approxi-
mately 10%. The Crank-Nicholson procedure takes considerably more computation
time for the unconfined case when elapsed time is long.
72-73:02F-055
ON THE UPTAKE OF TRITIUM BY SOIL WATER AND GROUNDWATER,
Ehhalt, D. H.
National Center for Atmospheric Research, Boulder, Colorado.
Water Resources Research, Vol. 9, No. 4, p 1073-1074, August 1973. 1 tab,
5 ref.
Descriptors: *Tritium, *Tracers, *Soil water, *Groundwater, Soil bacteria,
Evaporation, Precipitation (Atmospheric),, Oxidation.
Tritiated molecular hydrogen in the atmosphere is oxidized by soil microorgan-
isms and may contribute to the T input into soil with a rate of 5.4 T atom per
sq cm per sec. Thus groundwater studies using HTO as a tracer should take
this additional T input into account, and measurements of the
uptake of HT by local soil, along with the T deposition by rain, may be
required to give correct results.
72-73:02F-056
EFFECT OF ACCRETION ON DYNAMICS OF GROUNDWATER BETWEEN TWO CHANNELS,
El Nimr, A.
Slovenska Akademie Vied, Bratislava (Czechoslovakia), Ustav Hydrologie a
Hydrauliky.
Water Resources Research, Vol. 9, No. 4, p 1058-1064, August 1973. 6 fig,
5 ref.
Descriptors: *Groundwater movement, *Surface-groundwater relationships,
*Mathematical studies, Recharge, Evapotranspiration, Water balance, Infiltra-
tion, Evaporation, Seepage.
The effects of infiltration and evaporation on groundwater level and on the
amount of seepage to or from channels that bound an unconfined aquifer were
studied mathematically. The actual free-surface boundary conditions as well
as the exact differential equation were used to obtain the general solution.
Three particular cases were studied in detail. In the first, the accretion is
53
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considered to be constant, whereas, in the second, it is considered to vary
linearly with time. In the third, the accretion occurs only on a part of the
aquifer but does not occur on the other parts. For the three cases, the
rate of seepage^is given in mathematical forms as well as in dimensionless
curves. The free-surface profile was also drawn for several cases. A compari-
son with the solutions based on the Boussinesq equation is presented. These
approximate solutions give satisfactory results for shallow aquifers but
fail to give reasonably adequate results for relatively thick aquifers. The
results of these approximate methods deviate greatly from the exact solutions
for small values of time.
72-73:02F-057
MODIFIED MONTE CARLO APPLICATION TO GROUNDWATER MOVEMENT-THE SIMULTANEITY
PROCEDURES,
Shih, S. F.
Central and Southern Florida Flood Control District, West Palm Beach.
Water Resources Research, Vol. 9, No. 4, p 1029-1038, August 1973. 4 fig,
6 tab, 11 ref.
Descriptors: *Groundwater movement, *Monte Carlo method, *Mathematical studies.
Soil water movement, Statistical methods, Computers, Drawdown, Computer pro-
grams .
Identifiers: Simultaneity procedures.
By applying the Monte Carlo methods to problems of water movement in soils,
very difficult problems can often be treated easily, and solutions at only
a few points in a flow system can be obtained independently. A modified
Monte Carlo application, termed the simultaneity procedure, hastens the classi-
cal Monte Carlo application. So that the simultaneity procedure can be used
more widely, the techniques of a parallel simultaneity procedure and a succes-
sive simultaneity procedure were devised. Examples are presented not only
for the problems of groundwater movement and Thiessen coefficients but also
for the problems of general mathematics. Comparisons of results indicate
that the simultaneity procedure has the same accuracy as the classical Monte
Carlo method, but the computing time is reduced by approximately 30%-60%.
72-73:02F-058
EQUATION FOR ONE-DIMENSIONAL VERTICAL FLOW OF GROUNDWATER: 1. THE RIGOROUS
THEORY,
Gambolati, G.
Centre di Ricerca IBM di Venezia (Italy).
Water Resources Research, Vol. 9, No. 4, p 1022-1028, August 1973. 14 ref.
Descriptors: *Groundwater movement, *Mathematical studies, *Unsteady flow,
Porous media. Deformation, Equations, Elastic deformation, Elastic theory,
Hydraulic conductivity. Saturated flow, Stress, Strain.
A new mathematical derivation of the one-dimensional flow equation in an elas-
tic, saturated, porous medium is presented. The approach involves the consider-
ation of a fixed elemental volume in fixed coordinates. The derivation is
developed by starting from both Lagrangian and Eulerian definitions of the
position vector. The Lagrangian and Eulerian formulations prove to be equiva-
lent and provide the same outcome if they are correctly interpreted and con-
sistently applied. The rigorous equation contains an additional nonlinearity
resulting from the correct expansion of the partial spatial derivative of the
54
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grain velocity. It is also shown that an approach based on a deforming
element in fixed coordinates is simple and straightforward, since it does not
introduce the grain velocity into the development. However, it needs a parti-
cular definition for the compressibility different from the classical one. It
is proved that these two compressibilities are not equal; their , mathematical
link is derived.
72-73:02F-059
CALIBRATION OF DISTRIBUTED PARAMETER GROUNDWATER FLOW MODELS VIEWED AS A
MULTIPLE-OBJECTIVE DECISION PROCESS UNDER UNCERTAINTY,
Neuman, S. P.
Volcani Institute of Agricultural Research, Bet-Dagan (Israel), Department of
Soil and Water.
Water Resources Research, Vol. 9, No. 4, p 1006-1021, August 1973. 11 fig,
35 ref.
Descriptors: *Groundwater resources, *Flow, *Management, *Decision making,
*Linear programming, *Aquifers, Finite element analysis, Optimization,
Anisotropy, Systems analysis. Mathematical models, *Risks.
Identifiers: Multiple objectives, Sensitivity analysis.
Due to the deterministic nature of most groundwater flow models, there has been
a tendency to overlook the strong element of uncertainty that invariably enters
into the problem of parameter identification. Because of this uncertainty, an
approach based on the minimization of a single error functional generally
does not lead to satisfactory results. A multiple-objective decision process
is postulated, accounting for all the available information on the aquifer
flow system, as well as the range of environmental conditions under which the
system is expected to operate in the future. According to this new approach,
a continuous or discrete set of alternative solutions to the identification
problem is generated with the aid of mathematical programming techniques, and
the decision maker is asked to apply his own value judgment in selecting a
particular model structure. The method is illustrated by applying parametric
linear programming to a finite element model of steady state flow in a locally
anisotropic aquifer. The reliability of each parameter estimate is ascertained
using postoptimal sensitivity analysis.
72-73:02F-060
INTEGRODIFFERENTIAL EQUATIONS FOR SYSTEMS OF LEAKY AQUIFERS AND APPLICATIONS:
1. THE NATURE OF APPROXIMATE THEORIES,
Herrera, I., and Rodarte, L.
Universidad Nacional Autonoma de Mexico, Mexico City, Institute de Geofisica.
Water Resources Research, Vol. 9, No. 4, p 990-1005, August 1973. 4 fig,
27 ref.
Descriptors: *Groundwater movement, *Mathematical studies, *Equations, Aquifer
characteristics, Aquicludes, Hydrogeology.
Identifiers: *Leaky aquifers.
The dynamics of leaky aquifers are described by a system of integrodifferential
equations. Alternative expressions for the memory functions are obtained, and
it is shown that approximate theories of leaky aquifers correspond to several
ways of approximating the memory functions. By means of analysis of these
functions in the time domain it is possible to achieve a better understanding
of the nature of these approximations as well as to foresee the possibility of
55
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their application to new situations. These types of results constitute impor-
tant steps toward making the integrodifferential equations a powerful method
of analysis of the very complex situations arising in the study of actual
leaky aquifer systems. They can also be used to construct improved, simplified
methods for numerical computation.
72-73:02F-061
CAPILLARY PROPERTIES OF SOILS-INFLUENCE UPON SPECIFIC YIELD,
Duke, H. R.
United States Department of Agriculture, Agricultural Research Service, Fort
Collins, Colorado.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 4,
p 688-691, July-August, 1972. 6 fig, 2 tab, 9 ref.
Descriptors: *Specific yield, *Capillary action, Subsurface drainage, Ground-
water, Groundwater availability, Retention, Safe yield. Dug wells.
The discussion presented indicates that capillary properties of a porous medium
are important hydrologic parameters for situations of groundwater flow in which
capillary effects are generally considered negligible. Although the utility of
the specific yield concept has been proved many times under practical field
conditions, the hydrologist should be aware of the limitations of the data
he has collected. Of particular importance is an awareness of the errors
introduced by using specific yields determined under one set of experimental
conditions to predict ground water movement under completely different condi-
tions. The primary purpose has been to show that specific yield as classically
defined is not a unique property of the porous medium in which it is measured.
72-73:02F-062
COMPARISON OF STRENGTH TEST METHODS FOR CORRUGATED PLASTIC DRAINAGE TUBING,
Soribe, F. I., Fouss, J. L., and Schwab, G. O.
Ohio State University, Agricultural Engineering Department, Columbus.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 3,
p 445-447, May-June, 1972. 8 fig, 8 ref.
Descriptors: *Plastic deformation, *Plastic pipes, Closed conduits, Tile
drains. Tiles, Subsurface drains. Pipes.
The sand box and parallel plate methods for measuring the load deflection of
corrugated plastic drainage tile were evaluated. Twelve-inch lengths of un-
slotted plastic tubing at a temperature of 72 degrees F. and 5096 relative
humidity were tested using both methods. Deflection of the tubing was not
allowed to exceed 5%. The load is linearly related to the deformation for
deflections less than 596. in both test methods. Both methods give similarly
accurate results. The parallel plate method is preferred because it is much
faster to perform.
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72-73:02P-063
HYDRAULIC ROUGHNESS OF CORRUGATED PLASTIC TUBING,
Irwin, R.W., and Tsang, G.
Guelph University, Guelph, Ontario, Canada.
Transactions of the American Society of Agricultural Engineers, Vol 15,
No 2, p 290-291, 295, March-April, 1972. 3 fig, 1 tab, 10 ref.
(See 72-73:08B-007)
72-73:02F-064
WATER-MANAGEMENT PROBLEMS RELATED TO GROUNDWATER RIGHTS IN THE SOUTHWEST,
Thomas, H.E.
United States Geological Survey, Menlow Park, California.
Water Resources Bulletin, Vol 8, No 1, p 110-117, February 1972. 27 ref.
(See 72-73:04B-020)
72-73:02F-065
ROLE OF MODELS IN GROUNDWATER MANAGEMENT,
Weber, E.M., and Hassan, A.A.
California Department of Water Resources, Sacramento.
Water Resources Bulletin, Vol 8, No 1, p 198-206, February 1972.
(See 72-73:02A-008)
3 fig, 1 tab.
72-73:02F-066
MODELLING A GROUNDWATER AQUIFER IN THE GRAND PRAIRIE OF ARKANSAS,
Griffis, C.L.
Arkansas University, Agricultural Engineering Department, Fayetteville.
Transactions of the American Society of Agricultural Engineers, Vol 15, No 2,
p 261-263, March-April, 1972. 6 fig, 5 ref.
Descriptors: *Groundwater, *Computer models, *Mathematical models, Aquifer
management, Groundwater recharge, Recharge wells, Artificial recharge, Water
yield, Surface-groundwater relationships, Aquifers.
Most of the irrigation water for the Grand Prairie of Arkansas comes from the
Quaternary aquifer lying beneath the area. Constant pumping has lowered the
water table and shortened the water supply. A model was developed to investi-
gate the possibility of artificial recharging of the aquifer. The area was
divided into sections of one square mile. The flow equations were then
solved for each section. Various methods of recharge were then evaluated
using the model. Recharge wells were found to provide the best solution.
72-73:02F-067
GROUNDWATER MANAGEMENT,
Peters, H.J.
California Department of Water Resources, Sacramento.
Water Resources Bulletin, Vol 8, No 1, p 188-197, February 1972.
(See 72-73:02A-010)
1 fig.
72-73:02F-068
TENSIOMETER USE IN SHALLOW GROUND-WATER STUDIES,
Richards, S.J., Willardson, L.S., Davis, S., and Spencer, J.R.
Soil Physicist, Riverside California
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol 99, IR4, p 457-464, December 1973. 7 fig, 7 ref.
Descriptors: *Drainage, *Groundwater, Measurement, Piezometers, Pore water,
Pore pressure, Seepage, Tensiometers, Water table, Wells.
Tensiometers installed with a ground surface or other reference can be used
to determine groundwater equipotentials and the position of the water table
in the field. Tensiometer determined water tables were roughly comparable to
those measured with perforated wells in a sprinkler irrigated Coachella fine
sandy soil. Water differences depended on the flow conditions and proximity
57
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of the tensiometers to a drain. Shallow groundwater equipotentials can be
determined above and below the water table with a tensiometer system.
72-73:02F-069
APPROXIMATE SOLUTION FOR UNCONFINED SEEPAGE,
Desai, C.S.
United States Army Engineer Division, Waterways Experiment Station, Vicksburg,
Mississippi.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol 99, No IR1, p 71-87, March 1973. 12 fig, 24 ref.
Descriptors: *Drainage, *Finite element analysis, *Free surfaces, Interfaces,
Irrigation, Numerical analysis, Seepage, Transition flow.
An approximate solution procedure using the finite element method is developed
for one-dimensional unsteady free surface seepage. The numerical results are
compared with experiments on a viscous flow model and with analogue solutions.
Satisfactory correlation is obtained between the numerical and experimental
results. Results from the proposed procedure based on one-dimensional formu-
lation are compared with those from two- and three-dimensional formulations.
Numerical properties of the proposed procedure with respect to tiraewise
and spatial discretizations, magnitudes of permeability, and use of higher
order approximating functions are analyzed. The proposed solution can pro-
vide satisfactory and economical solutions for many practical problems that
can be idealized as one-dimensional.
72-73:02F-070
DETERMINATION OF EQUIVALENT RADII FOR RECTANGULAR DRAINS,
Warrick, A.W.
Arizona University, Tucson.
Soil Science Society of America Proceedings, Vol 37, No 5, p 809-811,
September-October 1973. 2 fig, 8 ref.
(See 72-73:02G-139)
72-73:02F-071
A FLOW PATH GROUND WATER SAMPLER,
Willardson, L.S., Meek, B.D., and Huber, M.J..
Imperial Valley Conservation Research Center, Brawley, California.
Soil Science Society of America Proceedings, Vol 36, No 6, p 965-966, November-
December 1972. 4 fig.
Descriptors: "Drainage, *Tile drainage, Salinity, Groundwater, Sampling,
A sampling system is described that enables collection of water samples from
different flow paths in the ground-water system around a tile drain. The
sampler can be installed as a regular part of a tile drainage system.
72-73:02F-072
VALIDITY OF DUPUIT-FORCHHEIMER EQUATION,
Murray, W.A., and Monkmeyer, P.L.
Lehigh University, Bethlehem, Pennsymvania. Department of Civil Engineering.
Society of Civil Engineers, Vol 99, No HY9, Paper 9997, p 1573-1583, September
1973. 4 fig, 16 ref, append.
Descriptors: *Dupuit-Forchheimer theory, *Groundwater movement, *Slopes,
Equations, Drawdown, Water yield, Mathematical studies, Aquifers.
The Dupuit-Forchheimer equation describing unconfined groundwater flow is limi-
ted by the underlying assumptions inherent in its derivation. A validity cri-
teriod developed from an analysis of the exact equations of motion shows that,
in general, the Dupuit-Forchheimer equation describes a rising water table
more accurately than a falling one. In the steady state the criterion reduces
to a simple restriction on the free surface slope. For unsteady flow, the
criterion involved both the free surface slope and the rate of. change of the
free surface position. The free surface slope must be no greater than 1:10
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if results are expected to be within 1% of exact. More accurate results should
be obtained by using data from either a recharging well or the recovery
period after pump shutdown rather than drawdown data.
72-73:02F-073
AGRICULTURAL DEMAND FOR WATER IN THE PECOS RIVER BASIN: AN ADDENDUM,
Gisser, M.
New Mexico University, Department of Economics, Albuquerque.
Water Resources Research Vol 9, No 5, p 1429-1432, October 1973. 4 tab, 2 ref.
Descriptors: *Water utilization, *Agriculture, Groundwater recharge, Ground-
water availability, Groundwater mining.
A study that deals with importing water to the Pecos River basin and using
this water without artificial recharging is compared with another study that
deals with the problem of recharging imported water into the aquifer. The
sensitivity of the demand for water function to changes in salinity con-
straints is explored and the possibility of reducing natural discharge of
water by lowering the evaporation rate of salt cedars is investigated.
72-73:02F-074
A GALERKIN-FINITE ELEMENT SIMULATION OF GROUNDWATER CONTAMINATION ON LONG
ISLAND, NEW YORK.
Pinder, G.F.
Princeton University, Department of Civil and Geological Engineering, Prince-
ton, New Jersey.
Water Resources Research, Vol 9, No 6, p 1657-1669, December 1973. 7 fig,
18 ref.
Descriptors: *Groundwater, *Pollutants, *Soil physics, Water pollution
sources, Water quality control, Chromium.
The Galerkin method of approximation in conjunction with the finite element
method of analysis may be used to simulate the movement of groundwater con-
taminants. In solving the groundwater flow and mass transport equations this
approach allows a functional representation of the dispersion tensor,
transmissivity tensor, and fluid velocity, as well as an accurate represen-
tation of boundaries of irregular geometry. A field application of the
method to chromium contamination on Long Island, New York, shows that accurate
simulations can be obtained by using the Galerkin-finite element approach.
72-73:02F-075
FLOW TOWARD PERIODIC TILE DRAINS,
Gyuk, I., Soriano, A., and Karadi, G.M.
Wisconsin University, School of Architecture, Milwaukee
Journal of Hydrology, Vol 19, No 2, p 113-129, June 1973. 9 fig, 3 ref.
Descriptors: *Drainage, *Groundwater, Tile drainage, Subsurface drainage,
Drainage practices, Drainage systems, Soil water movement, Drainage engineering.
The method of conformal mapping is applied to the analysis of transient flow
toward parallel periodic drains in a semi-infinite aquifer taking into con-
sideration the non-linear boundary conditions on the free surface. The
mapping function is expressed as a power series in time and the seepage domain
is mapped onto a domain of an auxiliary comples variable. Mapping is per-
formed in such a manner that the free surface will always remain the real
axis. Calculations are carried out for different ratios of drain depth to
drain spacing using various drain diameter to depth ratios.
72-73:02F-076
SOIL-SUCTION MEASUREMENTS FOR EVALUATION OF VERTICAL WATER FLOW AT GREATER
DEPTHS WITH A PRESSURE TRANSDUCER TENSIOMETER,
Strebel, O., Renger, M., and Giesel, W.
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Budensanstalt fur Bodenforschung und Niedersachsisches Landesamt fur Boden-
forschung, Hannover, Germany.
Journal of Hydrology, Vol 18, No 3/4, p 367-370, March 1973. 2 fig, 6 ref.
Descriptors: *Soil water, *Soil moisture, *Tensiometers, Moisture tension.
Soil water movement, Available water.
Periodic suction measurements at greater depths can be carried out in cased
boreholes using a temporarily installed pressure transducer tensiometer. The
time needed to reach constant suction values depends upon the tensiometer
prestressing and the soil suction, and amounts to about 15 min. to 2 1/2
hours according to general experience. With this technique, requiring
relatively low expense for instruments, the hydraulic gradient and - combined
with corresponding hydraulic conductivity values - the vertical water flow
can be determined at depths up to about 10 m.
72-73:02F-077
HAMMAT GADER (ISREAL): GEOCHEMISTRY OF A MIXED THERMAL SPRING COMPLEX,
Mazor, E., Kaufman, A., and Carmi, I.
The Weizmann Institute of Science, Rehovot, Israel.
Journal of Hydrology, Vol 18, No 3/4, p 289-303, March 1973. 8 fig, 7 tab,
14 ref.
Descriptors: *Groundwater, *Salinity, *Springs, Thermal springs, Cold springs,
Mineral water, Spring waters/ Water types.
A complex of four spring groups has been studied. The temperature and con-
centrations of dissolved ions reveal the springs to be mixtures of two types
of water whose characteristics were deduced by extrapolation. The hot end
member is enriched in He4, Ra226, and nitrogen, flushed from the hot aquifer
rocks. The Ne, Ar, Kr, and Xe have atmospheric isotopic compositions and
occur in relative elemental abundances similar to those dissolved in air-
saturated water. This indicates that both water end members originated
from rain water that equilibrated with air and infiltrated into the ground.
The Ar, Kr, and Xe concentrations revealed that both water types were formed
from rains that entered the ground at "paleotemperatures" of 19 + 3C. The
tritium and C14 values indicate the true hot end member to have an age
older than 117,000 years whereas the true cold end member has an age of
12,000 + 1,500 years. The cold spring D is mixed with about 3% post-
nuclear-tests rain water.
72-73:02F-078
EXPERIMENTS IN TRACING UNDERGROUND WATERS IN LIMESTONES,
Atkinson, T.C., Smith, D.I., Lavis, J.J., and Whitaker, R.J..
Bristol University (England) Department of Geography.
Journal of Hydrology, Vol 19, No 4, p 323-349, August 1973. 15 fig, 2 tab,
32 ref.
Descriptors: *Tracers, *Groundwater movement, *Karst hydrology, Limestones,
Dye releases, Karst, Hydrogeology, Surface-groundwater relationships.
Identifiers: *England.
Two experiments were conducted in the Carboniferous Limestone aquifer of the
Mendip Hills, Somerset, to compare the relative merits of differing ground-
water tracers. The tracers employed were lithium acetate, polyethylene powder,
Lycopodium spores, and the fluorescent dye Pyranine; all were introduced into
the aquifer at stream sinks. Lithium acetate and polyethylene powder were
totally unsuccessful. The rates of travel of the fluorescent dye and Lyco-
podium spores were very similar. Absolute concentration for dye can be
determined using a field continuous flow fluorometer. The quantitative
dye concentration data can be used with simultaneous measurements of discharge
at the spring to deduce the flow geometry of the system; the input, tributary,
distributary and maximum discharges in the system; and the volume of the under-
ground conduits. Exchange takes place between the flooded conduit and the
surrounding fissured bedrock in a manner analogous to bank storage in rivers
flowing on alluvium.
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72-73:02F-079
UNSTEADY FLOW TO BOTTOM DRAIN IN BOUNDED AQUIFER,
Krizek, R.J., Soriano, A., and Gyuk, I.
Northwestern University, Tkchnologioal Institute, Evanston, Illinois.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol 99, No IR2, p 169-182, June 1973. 6 fig, 11 ref.
Descriptors: *Groundwater, *Aquifers, *Aquifer characteristics, Drainage,
Tile drains, Irrigation, Seepage, Transition flow.
Identifiers: Conformal mapping. Complex variables.
The problem of transient seepage toward a drain at the bottom of a homogeneous,
isotropic aquifer is presented. The dependent variables are the position
of the free surface, the flow rate, and the pore pressure distribution around
the drain, and these are determined as functions of time for various depths
of drainage and drain sizes; the characteristics of the aquifer are specified
in terms of its coefficient of permeability and its effective porosity. The
mathematical statement of this problem yields to a time-dependent potential
field within a strip domain bounded by the impervious bottom, the moving free
surface, and a small semicircular contour representing the drain. To overcome
the difficulty of a moving boundary, a conformal mapping technique is used to
transform the problem into a new plane in which the free surface remains
straight and fixed. The solution of the problem is found to the third
order of time, and an upper bound is given to limit the range within which it
is valid.
72-73:02F-080
EVALUATION OF WATER FLUX ABOVE A DEEP WATER TABLE USING THERMOCOUPLE PSYCHO_
METERS,
Enfield, C.G., Hsieh, J.J.C., and Warrick, A.W.
Environmental Protection Agency, Robert S. Kerr Environmental Research
Laboratory, Ada, Oklahoma.
Soil Science Society of America Proceedings, Vol 37, No 6, p 968-970,
November-December, 1973. 3 fig, 12 ref.
Descriptors: *Groundwater, *Soil water, Potential flow, Recharge, Unsaturated
flow.
Deep water flow was evaluated in a Washington desert environment using hydraulic
conductivity and potential gradients. Thermocouple psychrometers and temper-
ature transducers were installed to depths of 94 m. in the soil profile and
used to measure the potential gradients. The hydraulic conductivity
was calculated using a modified Millington and Quirk equation and the soil
moisture characteristic curve. The thermal fluid diffusivity was calculated
and used to estimate flow induced by thermal gradients. Under the condi-
tions studied, a more refined analysis of the thermally induced flow is
required to give a definite answer as to the direction of flow. It was
concluded, that is flow existed at this location, it was less than 1 cm/year.
72-73:02F-081
ON THE LEAKAGE ASSUMPTION APPLIED TO EQUATIONS OF GROUNDWATER FLOW,
Streltsova, T.D.
Birmingham University, Civil Engineering Department, Birmingham, Great Britain.
Journal of Hydrology, Vol 20, No 3, p 237-253, November 1973. 3 fig, 24 ref.
Descriptors: *Groundwater, *Computer models, *Mathematical models, Confined
water, Aquifers, Groundwater potential, Soil water.
The behavior and the delayed response of flow to a well in an unconfined
aquifer is considered on the basis of recognition of the variable vertical
movement of flow inherent in unconfined flow. The effect of elastic storage
is taken into account. The typical S-shaped form of the characteristic time
drawdown curve of an unconfined aquifer is analyzed. A procedure for deter-
mining the unconfined parameters is described. It is shown that the
vertical components' of flow are a significant factor in the delayed response
61
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of an unconfined aquifer while the contribution of the unsaturated zone is
essentially subordinate. An equation including allowance for the drainage from
the unsaturated zone is derived.
72-73:02F-082
A DISCRETE SPACE CONTINUOUS TIME MODELING APPRAOCH TO NONSTEADY FLOW IN A
LEAKY AQUIFER SYSTEM OF FINITE CONFIGURATION,
Marino, M.A., and Yeh, W.W.G.
California University, Davis.
Journal of Hydrology, Vol 20, No 3, p 255-266, November 1973. 5 fig, 11 ref.
Descriptors: *Groundwater, *Computer models, *Mathematical models, Confined
water, Aquifers, Groundwater potential, Soil water.
Existing analytical procedures for nonsteady flow in a leaky confined aquifer
assume that the aquifer system is realy infinite. A technique is presented
that treats a leaky confined aquifer system of finite configuration. By
means of a discrete space continuous time (DSCT) modeling approach, the
partial differential equation governing the flow system is transformed into
a set of ordinary differential equations that can be easily integrated numeri-
cally on a high speed digital computer using available scientific subroutines.
The finite difference formulation is in effect an explicit scheme. A cri-
terion is developed for which the scheme is computationally stable. A
numerical example is presented.
72-73:02F-083
GROUNDWATER POLLUTION AND CONSERVATION,
Environmental Science and Technology, Vol 6, No 3, p 213-215, March 1972. 2
fig.
Descriptors: *Groundwater, *Aquifers, *Aquifer systems, Areal hydrogeology
Bodies of water, Dug wells, Groundwater availability, Groundwater resources,
Soil water.
A general overview of the groundwater reserves in the United States is
presented. Possible sources of contamination is outlined. Suggested programs
for regulation of groundwater use are discusses. A map showing the known
aquifers in the United States that are capable of yielding wells of 50 gpm
or more at salinity levels not higher than 2000 ppm was developed.
72-73:02F-084
INJECTION WELLS POSE A POTENTIAL THREAT,
Environmental Science and Technology, Vol 6, No 2, p 120-122, February
1972. 3 fig.
Descriptors: *Groundwater, *Waste disposal wells. Injection wells.
Underground waste disposal, Waste disposal, Waste storage, Waste water
disposal.
The field of injection wells for waste disposal is explored. There are
literally tens of thousands of wells now being used. There are no records
of areas where wastes have already been injected. There is a need for
further research to develop the needed technology. Since the effects of
pollutants in the groundwater system are both slow to appear and correct,
great care should be taken to minimize the risks.
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Section VII
WATER CYCLE
WATER IN SOILS (GROUP 02G)
72-73:02G-001
CATION ADSORPTION IN ONE-DIMENSIONAL FLOW THROUGH SOILS: A NUMERICAL SOLUTION,
Lai, S.H., and Jurinak, J.J.
Utah State University, Logan. Department of Soil Science and Biometeorology.
Water Resources Research, Vol 8, No 1, p 99-107, February 1972. 9 fig, 1
tab, 15 ref.
Descriptors: *Cation adsorption,*Numerical analysis, *Soil chemistry, Dis-
persion, Adsorption, Soil water movement, Clays, Ion exchange.
A numerical method was developed to solve the problem of the cation adsorption
operation involving a general nonlinear exchange function. The method may be
applied to solve the cation adsorption operation involving five different
types of exchange functions. The adsorption of a cation depends on the equil-
ibrium behavior of the counterions, which is defined by the exchange function.
The separation factor is used as an index of the adsorption operation.
72-73:02G-002
SPECIFIC CONDUCTANCE MODEL FOR NATURAL WATERS AND SOIL SOLUTIONS OF LIMITED
SALINITY LEVELS,
Tanji, K.K., and Biggar, J.W.
California University, Davis, Department of Water Science and Engineering,
Water Resources Research, Vol 8, No 1, p 145-153, February 1972. 4 tab,
13 ref.
Descriptors: *Conductivity, *Soil water, *Aqueous solutions, *Saline water,
*Electrical conductance, Solutes, Water chemistry, Water properties, Ions,
Water temperature.
Identifiers: *Specific conductance
The specific conductance of waters and soil solutions may be estimated with
a simplified multicomponent conductance model. This model considers solute
composition and concentration and a lumped coefficient for ionic interactions,
retardation effects, and ion association. The effect of temperature on specific
conductance is also considered. Comparison of measured and calculated
specific conductances indicate that this empirical model is most applicable
to waters and soil solutions with limited salinity levels. Conductance is
approximately related to the total soluble cations and the total dissolved
salts.
72-73:026-003
ON THE TENSOR CONCEPT OF UNSATURATED ANISOTROPIC HYDRAULIC CONDUCTIVITY,
Cisler, J.
Technical University of Prague (Czechoslavakia). Lab. of Soil Science.
Water Resources Research, Vol 8, No 2, p 525-528, April 1972. 1 fig, 7 ref.
Descriptors: *Hydrualic conductivity, *Soil water movement, *Anisotropy,
*Mathematical studies. Seepage, Groundwater movement, Physical properties,
Darcy's Law.
Identifiers: Hydraulic conductivity tensor.
Unsaturated hydraulic conductivity can be regarded as a second order tensor,
the coefficients of which depend on soil moisture suction or soil moisture
content. General equations for the three-dimensional anisotropic unsaturated
flow of water in porous media must involve nine coefficients of the hydraulic
conductivity tensor, all of which are, in general, nonzero. Equations for
horizontal anisotropic unsaturated flow can be reduced to an orthotropic form
63
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with principal hydraulic conductivities, provided the principal axes of the
conductivity tensor do not rotate when the moisture content or the soil moisture
suction changes. This condition is fulfilled only for a constant ratio of
hydraulic conductivities in different directions that is independent of the
soil moisture suction or soil moisture content. In this case the flow velocity
is given by the simple Darcy type equation without the cross coefficients of
hydraulic conductivity. A simple experimental method is proposed to determine
the diagonal and cross coefficients of the hydraulic conductivity as functions
of the soil moisture suction for horizontal unsaturated steady flow in ani-
sotropic porous media.
72-73:020-004
DRAINAGE IN SOILS WITH INITIAL GRADIENT,
Valsangkar, A.J., and Subramanya, K.
Indian Inst. of Tech., Kanpur. Department of Civil Engineering.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol 98, No IR2, p 309-315, June 1972. 5 fig, 11 ref.
Descriptors: *Trenches, *Non-Newtonian flow, *Groundwater movement, *Flow
characteristics, *Soil water movement, Drainage water, Dupuit-Forcheimer
theory, Confined water, Hydraulic gradient, Hydraulic models, Theoretical
analysis.
Identifiers: *Unconfined flow, *Initial gradient.
Seepage through clayey and loamy soils is a common problem in the field and
drainage engineering. Like many non-Newtonian fluids, seepage through such
soils is initiated only when the hydraulic gradient exceeds a certain value
called the initial gradient. Consequences of this type of non-Darcy behavior
are of potential interest in several disciplines. In drainage problems non-
recognition of the initial gradient will result in inefficient layout of the
drains. Assuming the Dupuit-Forcheimer assumptions to be valid, a general
solution for unconfined flow into a trench has been derived. The importance
of the initial gradient in affecting the spacing of the trench and discharge
reduction, is emphasized. In confined flow, the presence of the initial
gradient reduces the effective head.
72-73:02G-005
MOVING WATER TABLES IN TILE-DRAINED SOILS,
Awan, N.M., and O'Donnell, T.
West Pakistan University of Encingeering and Technology, Lahore. Department
of Civil Engineering.
American Society of Civil Engineers, Journal of the Irrigation and Drainage
Division, Vol 98, No IR3, p 459-477, September 1972. 9 fig, 17 ref.
Descriptors: *Water level fluctuations, *Hydraulic models, *Water table,
*Tile drainage, Model studies, Drawdown, Steady flow, Subsurface drainage,
Tile drains, Groundwater movement,
Identifiers: *Hele-Shaw mocels.
A Hele-Shaw analogy of the tile drainage problem was used to provide data on
moving water table characteristics. The experimental data for water table
recession following complete cessation of recharge are presented in comparison
with five analytical solutions and two numerical solutions. Experimental
data on rising water tables following sudden commencement of recharge are
also presented. The drainage variables whose effects on the moving water
table are reported are: (1) The initial or final steady-state mid-drain water
table height; (2) the depth of the impermeable bed below the drain axis; and
(3) the drain size. Drainage characteristics are virtually independent of
the depth of the impermeable bed below the drain axis once that depth is one-
eight or more of the spacing between drains, regardless of the initial
steadystate water table height. For given values of an appropriate dimension-
less time parameter, the proportional amount of rise increases with increasing
ym/d, but at a progressively diminishing rate.
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72-73:020-006
MODELING INFILTRATION DURING A STEADY RAIN,
Mein, R.G., and Larson, C.L.
Minnesota University, St. Paul. Department of Agricultural Engineering.
Water Resources Research, Vol 9, No 2, p 384-394, April 1973. 10 fig, 2 tab,
23 ref.
Descriptors: *Infiltration, *Rainfall-runoff relationships, *Mathematical
models, Wetting, Soil water movement, Rainfall intensity. Hydraulic conductivity.
A simple two-stage model describes infiltration under a constant intensity
rainfall into a homogeneous soil with uniform initial moisture content. The
first stage predicts the volume of infiltration to the moment at which sur-
face ponding begins. The second stage, which is the Green-Ampt model modi-
fied for the infiltration prior to surface saturation, describes the subse-
quent infiltration behavior. A method is given for estimating the mean
suction of the wetting front. Comparison of the model predictions with experi-
mental data and numerical solutions of the Richards equation for several
soil types shows excellent agreement.
72-73:020-007
PERTURBATION ANALYSIS OF TWO-PHASE INFILTRATION,
Noblanc, A., and Morel-Seytoux, H.J.
Colorado State University, Fort Collins, Cepartment of Civil Engineering.
Proceedings, American Society of Civil Engineers, Journal of the Hydraulics
Division, Vol 98, No HY9, Paper 9186, p 1527-1541, September 1972. 10 fig,
5 ref, append.
Descriptors: *Infiltration, *Soil water movement, *Unsaturated flow, "'Cap-
illary action, Analytical techniques, Percolation, Permeability, Hydraulic
conductivity, Capillary conductivity.
Identifiers: *Perturbation analysis, *Multiphase flow.
An analytical treatment for the problem of one-dimensional infiltration into
a homogeneous porous medium is presented. Movement of both the air phase and
the water phase and compressibility of the air are considered. The procedure
assumes that some capillary terms can be neglected in the saturation equation,
whereas all capillary terms are retained in an integral equation for the un-
known total flow. Infiltration rate curves are obtained for a number of
situations involving different boundary or initial conditions or both. Com-
parisons are made with results of an earlier and simpler procedure, confirming
the validity of the simpler procedure. It is recommended that the traditional
unsaturated flow equation be abandoned in favor of the two-phase flow approach.
72-73:026-008
A TECHNIQUE USING POROUS CUPS FOR WATER SAMPLING AT ANY DEPTH IN THE
UNSATURATED ZONE,
Wood, W.W.
Geological Survey, Lubbock, Texas.
Water Resources Research, Vol 9, No 2, p 486-488, April 1973. 2 fig, 2 ref.
Descriptors: *Sampling, *Soil water, *Soil moisture, *Lysimeters, *Zone
of aeration, Instrumentation, Unsaturated flow.
Identifiers: *Suction lysimeters, *Soil water sampling, Porous cup lysimeters.
Porous cups or suction lysimeters provide a simple and direct method for
collecting water samples in the unsaturated zone. A new procedure is described
in which a check valve is placed in the sample collection assembly. This
construction permits complete collection at any depth without the loss of sam-
ples. A detailed description of construction and operation illustrates the
advancement over previous designs.
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72-73:026-009
NUMERICAL TREATMENT OF THE UNSATURATED WATER FLOW EQUATION: COMPARISON OF
EXPERIMENTAL AND COMPUTED RESULTS,
Giesel, W., Renger, M., and Strebel, O.
Niedersaechsisches Landesaint fuer Bodenforschung, Hanover (West Germany).
Water Resources Research, Vol 9, No 1, p 174-177, February 1973. 4 fig, 5 ref.
Descriptors: *Infiltration, *Unsaturated flow, *Numerical analysis, *Equation,
Infiltrometers, Laboratory tests, Hysteresis, Soil water movement.
A numerical solution of the differential equation governing the unsaturated
vertical water flow in soils was applied to results of infiltration and redis-
tribution experiments carried out in a sand column. The boundary condition
at the bottom was determined through the fact that during the first 3-4 hours
all the water accumulated in the soil. The computed and measured water contents
and water suctions agree well. Hysteresis is taken into consideration in this
numerical treatment. The agreement between experimental and numerical results
is satisfying.
72-73:02G-010
MODIFIED APPROACH TO CAPILLARY HYSTERESIS BASED ON A SIMILARITY HYPOTHESIS,
Mualem, Y.
Technion-Israel Inst. of Technology, Haifa. Department of Civil Engineering.
Water Resources Research, Vol 9, No 5, p 1324-1331, October 1973. 8 fig,
23 ref.
Descriptors: *Unsaturated flow, *Capillary action, *Hysteresis, Soil water
movement, Wetting, Drying, Capillary conductivity, Pores.
Identifiers: Capillary hysteresis.
A simplified approach to the capillary hysteresis phenomenon is based on a
similarity hypothesis. A simple method predicts the relationships between
the capillary head and the water content within the hysteretic loop. Only the
boundary curves of the main loop are required in order to derive analytically
the scanning curbes. The realiability of the proposed model is demonstrated
by a comparison of the predicted scanning curves with measured ones. The
computed results are often in more satisfactory agreement with experiments
than those obtained with the use of the general Neel-Everett model.
72-73:020-011
MOISTURE VARIATION AT THE SOIL SURFACE AND THE ADVANCE OF THE WETTING FRONT
DURING INFILTRATION AT CONSTANT FLUX,
Braester, C.
Technion-Israel Inst. of Tech. Haifa. Department of Civil Engineering.
Water Resources Research, Vol 9, No 3, p 687-694, June 1973. 4 fig, 2 tab,
16 ref.
Descriptors: *Infiltration, *Soil water movement, *Numerical analysis, *Equa-
tions. Finite element analysis, Unsaturated flow, Hydraulic conductivity,
Saturated flow, Diffusivity, Wetting.
The problem of infiltration at constant flux at the soil surface was solved
approximately in an analytical closed form. The solutions are valuable when
dealing with sprinkler irrigation or infiltration of rain. Infiltration into
a semi-infinite soil column and infiltration into a soil column of finite
length with a constant water table were considered. Analytical and numerical
results were compared. The analytical solutions provide a satisfactory
prediction of the moisture content at the soil surface and of the advance
of the wetting front. The results are presented in a dimensionless form.
72-73:026-012
RELATIVE LEACHING POTENTIALS ESTIMATED FROM HYDROLOGIC SOIL GROUPS,
Engieihd, C.B.
"Agricultural Research Service, Beltsville, Maryland. Hydrograph Lab.
Water Resources Bulletin, Vol 9, No 3, p 590-597, June 1973. 2 fig, 2 tab, 7 ref
66
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Descriptors: *Leaching, *Soil water movement, *Soil groups, Recharge, Ground-
water movement, Infiltration, Soil properties, Path of pollutants, Percolation.
Leaching of soils with water can be both beneficial and hazardous at the
same time, by removing salts harmful to plants and contributing dissolved
substances to groundwater. The leaching potential of a given soil is
difficult to assess, even with complex instrumentation. The final infiltra-
tion rates associated with the Hydrologic Soil Groups used by the USDA
Soil Conservation Service in watershed planning may provide a useful guide in
estimating quantities of leaching water moving through soil profiles.
72-73:02G-013
HORIZONTAL SOIL-WATER INTAKE THROUGH A THIN ZONE OF REDUCED PERMEABILITY,
Ahuja, L.R., and Swartzendruber, D.
Purdue University, Lafayette, Indiana.
Journal of Hydrology, Vol 19, No 1, p 71-89, May 1973. 8 fig, 29 ref.
Descriptors: *Infiltration, *Percolation, *Soil water movement, *Unsaturated
flow, Saturated flow, Numerical analysis, Hydraulic conductivity, Wetting.
Identifiers: *Horizontal infiltration.
One-dimensional, horizontal soil-water absorption through a thin zone of con-
stant nonzero hydraulic resistance was examined theoretically as well as a
similarity reduction of the problem for early to intermediate times. The
flow equations were transformed by introducing a dimensionless parameter which
enables the solution for any value of thin-zone resistance to be obtained
from the solution for a given known thin-zone resistance. At the inlet
boundary between the thin zone and the soil column, the soil-water content
increases with time to approach the saturated value. The cumulative absorption
of water by the soil column increases more than proportionally with the square
root of time for early and intermediate times, and approached a square-root-
or-time proportionality at large times. For both the soil-water content at
the inlet boundary and the cumulative water absorption by the soil column,
simple expressions arise from the similarity-reduction analysis, which is
based on specific functional forms of the soil-water diffusivity and suction
head. For early to intermediate times of flow, the similarity-reduction analy-
sis describes adequately the calculated numerical-solution flow data for Yolo
soil, as well as the measurement obtained experimentally on Salkum silty clay
loam.
72-73:02G-014
THE INFILTRATION ENVELOPE: RESULTS FROM A THEORETICAL INFILTROMETER,
Smith, R.E.
Agricultural Research Service, Tucson, Arizona, Southwest Watershed Research
Center.
Journal of Hydrology, Vol 17, No 1-2, p 1-22, October 1972. 13 fig,
4 tab, 10 ref.
Descriptors: ^Infiltration , "Soil water movement, *Mathematical models,
Numerical analysis, Unsaturated flow, Unsteady flow, Wetting, Porous media,
Equations.
The theoretical partial differential equation for unsaturated soil moisture
flow may be solved by a versatile numerical scheme designed for accurate
simulation of infiltration from various patterns of rainfall. This model may
be used to study the independent effects of soil type, initial soil moisture,
rainfall rate and rainfall pattern. The solution is expressed as a simple
parametric model for vertical infiltration. Infiltration from a suddenly
ponded surface is shown to be an asymptotic limit to increasing rainfall
rates. A single dimensionless for mula describes the infiltration decay
curves for all soils, initial conditions, and rainfall rates tested,
and another dimensionless relation predicts time to ponding under arbitrary
rainfall patterns as a function of infiltrated rainfall depth. The effect
of initial soil moisture is well described by a simple linear effect on the
normalizing time in the dimensionless system. Uses and implications of these
results are discussed.
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72-73:026-015
A HYDRAULIC MODEL FOR THE SIMULATION OF NON-HYSTERETIC VERTICAL UNSATURATED
FLOW OF MOISTURE IN SOILS,
Wind, G.P.
Institute for Land and Water Management Research, Wageningen (Netherlands)
Journal of Hydrology, Vol 15, No 3, p 227-246, March 1972. 11 fig, 1 tab,
5 ref.
Descriptors: *Unsaturated flow, *Hydraulic models, *Infiltration, Drainage,
Seepage, Soil-water movement, Model studies, Unsteady flow. Hydraulic conduc-
tivity, Capillary conductivity. Saturated flow. Hysteresis.
A hydraulic model used to simulate infiltration and drainage processes in
soils of low permeability was built. It consists of a number of vessels,
each simulating a layer of soil with its moisture characteristic, connected
by a number of tubes, simulating capillary conductivity. The model reacts in
nearly the same manner as the soil would, according to knowledge of the flow
processes and parameters. The model can be used to study nonsteady state
infiltration and drainage processes.
72-73:026-016
HYDRATION OF CATIONS ADSORBED ON A CLAY SURFACE FROM THE EFFECT OF WATER
ACTIVITY ON ION EXCHANGE SELECTIVITY,
Laudelout, H., Van Bladel, R., and Robeyns, J.
Louvain University, (Belguim)
Soil Science Society of America Proceedings, Vol 36, No 1, p 30-34,
January-February 1972. 7 fig, 15 ref.
Descriptors: *Cation adsorption, *Clay minerals, *Ion exchange, Thermodynamics,
Water chemistry, Hydration, Salinity, Trace elements, Adsorption.
Ion exchange equilibria for four pairs of singly charged ions in a mont-
morillonite clay were calculated at various total normalities of the equilibrium
solution at 25 C. Only the trace region for the preferred ion was investi-
gated. The effect of solvent activity on the selectivity coefficient was
established; in each case the expected linear relationship between their loga-
rithms was observed. The values for the differences of the ion hydration
numbers calculated from this purely thermodynamic relationship were consistent
and were comparable with values that could be deduced from basal spacings
or anion exclusion volume data.
72-73:02G-017
AN IMPROVED FORM OF SOIL-WATER DIFFUSIVITY FUNCTION,
Ahuja, L.R., and Swartzendruber, D.
Purdue University, Lafayette, Indiana. Department of Agronomy.
Soil Science Society of America Proceedings, Vol 36, No 1, p 9-14, January-
February 1972. 5 fig, 1 tab, 25 ref.
Descriptors: *Infiltration, *Diffusivity, *Soil water movement, *Computer
programs, Numerical analysis, Saturated flow, Unsaturated flow, Hydraulic
conductivity, Soil water, Soil moisture.
Soil-water diffusivity is expressed by a functional form which becomes infinite
as the soil-water content approaches a constant value, such as the saturated
or near-saturated value. The function begins at zero value, and shows an
approximately exponential rise in the intermediate soil-water content range.
When combined with an unsaturated hydraulic function, qualitatively reasonable
forms for the relationship between water and suction head can be inferred.
A computer program was developed to determine the characterizing parameters
in the function by a least-squares fit to experimental data for horizontal
water absorption. The program uses an optimum-seeking technique with numerical
solutions of the flow equations as obtained by Philip's method. For different
types of soils and several bulk densities, the new functional form was
compared with the commonly used exponential expression and was found to be
more representative.
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72-73:02G-018
DIFFUSION OF ZINC IN SOIL: I. THE INFLUENCE OF SOIL MOISTURE,
Warncke, D.D., and Barber, S.A.
Purdue University, Lafayette, Indiana. Department of Agronomy.
Soil Science Society of America Proceedings, Vol 36, No 1, p 39-42,
January-February 1972. 1 fig, 5 tab, 9 ref.
Descriptors: *Diffusion, *Zinc radioisotopes, *Trace elements, *Soil moisture,
Soil water movement, Adsorption, Ion transport, Aqueous solutions, Tracers,
Soil chemistry.
Identifiers: *Zinc
Effective zinc diffusion coefficients were determined at several soil moistures
on six soils by allowing Zn-65 to diffuse from the soil into cation exchange
resin paper on the surface of the soil. At 13% volumetric moisture diffusivity
values ranged from 10 to the minus llth power to 10 to the minus 8th power
sq cm/sec, with the range narrowing as the soils approached moisture saturation.
In five of six soils, the effect of increasing moisture level on diffusivity
could be explained by its effects on tortuosity and on solution Zn concen-
tration. When solution Zn remained constant as moisture level increased,
the relation between diffusivity and volumetric moisture was hyperbolic.
When solution Zn level dropped as moisture increased, diffusivity changed
very little.
72-73:02G-019
LEACHING OF A SURFACE LAYER OF SODIUM CHLORIDE INTO TILE DRAINS IN A SAND-
TANK MODEL,
Mulqueen, J., and Kirkham, D.
Iowa State University, Ames
Soil Science Society of America Proceedings, Vol 36, No 1, p 3-9, January-
February 1972. 7 fig, 2 tab, 13 ref.
Descriptors: *Leaching, *Saline soils, *Soil chemistry, *Land reclamation,
Soil water movement, Model studies, Hydraulic models, Chlorides, Salts,
Saline water systems.
The leaching of NaCl through tile drains from a surface layer of salinized
sand was studied in a sand-tank model. Each experiment was conducted with a
steady-state, arch-shaped water table maintained by recharge from a battery
of capillary tubes that gave a uniform infiltration over the model. All the
salt was leached from the model. Intense fingering developed in all experi-
ments in which a salinized layer was used. Fingering caused a rapid and
erratic redistribution of salt within the model and an erratic variation in
the salinity of the drainage water until about 1 pore volume had drained.
The higher the initial sand salinity, the more intense was the fingering, the
longer were the fingers, and the higher were the finger velocities. The
behavior of the fingering transition zone was controlled by the interaction
between the density gradients and the hydraulic gradient; this latter depends
on the recharge rate and the drain spacing. The salinity of the outflow
drainage water rose quickly to a peak and then declined almost as quickly for
a short period, after which it reduced more gradually. After about 1 pore
volume had drained, the salinity of the drainage water declined exponentially
in all salinized experiments. Experimental curves fitted closely to an ex-
ponential relationship except initially and where fingering resulted in
erratic variations.
72-73:02G-020
DIFFUSION OF ZINC IN SOIL: II. THE INFLUENCE OF SOIL BULK DENSITY AND ITS
INTERACTION WITH SOIL MOISTURE,
Warncke, D.D., and Barber, S.A.
Purdue University, Lafayette, Indiana. Department of Agronomy.
Soil Science Society of America Proceedings, Vol 36, No 1, p 42-46, January-
February 1972. 4 fig, 3 tab, 13 ref.
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Descriptors: *Diffusion, *Zinc radiosotopes, *Trace elements, *Soil moisture,
Soil water movement, Adsorption, Ion transport, Aqueous solutions, Tracers,
Soil chemistry.
Identifiers: *Zinc.
Effective zinc diffusion coefficients were determined at four soil bulk
densities and three moisture levels in five salt loam soils. The tortuosity
of the diffusion path for each set of soil conditions was estimated from Cl-36
diffusion data. In each soil and for each soil moisture level the diffusion
path was least tortuous near 1.3 g/cc. The order for the influence of soil
bulk density on tortuosity was 1.6>15.>1.1>1.3 g/cc. Soil bulk density inter-
acted significantly with soil moisture in affecting the Zn diffusion coeffi-
cients. The maximum rate of Zn diffusion dit not always occur at a soil bulk
density of 1.3 g/cc where the diffusion path was least tortuous. At 20
to 30% moisture the Zn diffusion rate reached a maximum near 1.5 g/cc. As
the soil moisture was increased, a reduction in the effect of the interaction
of Zn with the soil was greater than the effect of tortuosity in determing the
effective rate of Zn diffusion in each soil. When the bulk density was
increased from 1.5 to 1.6g/cc, an increase in both the degree of interaction
and tortuosity combined to cause a sharp decrease in the Zn diffusion coeffi-
cient.
72-73:02G-021
FRACTIONATION OF CATION EXCHANGE CAPACITY FOR ASSESSING SOIL AND WATER SODICITY,
Bower, C.A., and Rhoades, J.D.
Agricultural Research Service, Riverside, California. Salinity Lab.
Soil Science Society of America Proceedings, Vol 36, No 1, p 174-175,
January-February 1972. 1 tab/ 7 ref.
Descriptors? *Hydraulic conductivity, *Ion exchange, *Clay minerals, Cation
exchange, Potassium, Regression analysis.
Identifiers: *Vermiculite.
Soils containing appreciable amounts of vermiculite react atypically to Na.
The regression coefficient of the relation between the exchangeable-sodium ratio
and the sodium-adsorption ratio is appreciably greater for soil vermiculites
than for montmorillonite and most soils. Further, at constant salt
concentration, the exchangeable-sodium percentage associated with a given
percentage decrease in hydraulic conductivity is greater for high-vermiculite
than for low-vermiculite soils. For eight soils having a wide range of vermi-
culite contents, the exchangeable-sodium percentage required to cause a 25%
reduction in hydraulic conductivity at a salt concentration of about 10 meg/
liter was highly correlated (r=0.95) with cation exchange capacity after K
fixation.
72-73:020-022
USE OF PHYSICAL METHODS TO EXPAND SOIL SURVEY INTERPRETATIONS OF SOIL DRAINAGE
CONDITIONS,
Bouma, J.
Wisconsin University, Madison. Department of Soil Science.
Soil Science Society of America Proceedings, Vol 37, No 3, p 413-421,
May-June 1973. 9 fig, 36 ref.
Descriptors: *Hydraulic conductivity, *Model studies, *Soil water movement.
Numerical analysis. Hydraulic models, Permeability, Soil physical properties,
Soil surveys. Soil physics.
Complex numerical procedures and simple approximate physical methods, both
requiring hydraulic conductivity and moisture retention data, can be used
to calculate hydrodynamic soil behavior for a variety of simplified boundary
conditions. Two approximate methods were applied to four Wisconsin soils in
which measurements of hydraulic conductivity had been made in
Two soils that had been placed previously in different drainage classes on the
basis of differences in soil mottling, actually had comparable hydrologic
properties. Soil survey methods do not provide the quantitative data
needed for predicting what soil behavior will be under environmental conditions
that have changed temporarily or permanently.
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72-73:02G-023
ANION EXCLUSION AND COUPLING EFFECTS IN NONSTEADY TRANSPORT THROUGH UNSATURATED
SOILS: I. THEORY,
Bresler, E.
Volcani Inst. of Agricultural Research, Bet-Dagan (Israel) Department of Soil
Physics.
Soil Science Society of America Proceedings, Vol 37, No 5, p 663-669, September-
October 1973. 4 fig, 1 tab, 22 ref.
Descriptors: *Dispersion, *Soil water movement, *Ion exchange, *0smosis,
*Ion transport, Mathematical models, Numerical analysis, Clays, Simulation
analysis, Unsaturated flow, Adsorption.
A simulation model for the simultaneous transport of anions and water takes
into account physicochemical interaction between the solutes and the soil
matrix. The effects of convection, ionic diffusion, methanical dispersion,
anion exclusion (negative adsorption), and coupling phenomena are considered
jointly. The dependence of the osmotic efficiency coefficient and anion
exclusion of soil water content and solution concentration are estimated from
diffuse double-layer theory and hydrodynamic considerations. These estimates
compare favorably with available data on clays and soils. The nonsteady flow
equations are solved by a numerical approach that eliminates numerical dis-
persion. An infiltration experiment was characterized by relatively high water
contents and rapid flow; this showed that osmotic gradients are of minor
importance. A slight anion exclusion brought about some improvement in the
comparison between the theoretical data.
72-73:02G-024
WATER RECHARGE IN A SOIL WITH SHRINKAGE CRACKS,
Blake, G., Schlichting, E., and Zimmerman, U.
Hohenheim University, Stuttgart-Hohenheim (West Germany)
Soil Science Society of America Proceedings, Vol 37, No 5, p 669-672,
September-October 1973. 4 fig, 2 tab, 8 ref.
Descriptors: *Infiltration, *Recharge, *Soil water movement, Interstices,
Tracers, Soil physical properties, Tritium, Expansive soils, Shrinkage,
Permeability, Hydraulic conductivity.
Identifiers: *Shrinkage cracks.
Flow of water was studied in a relatively dry Pelosol characterized by fine
shrinkage cracks between peds. The coefficient of linear expansion was 0.115
in peds of the Bva horizon between oven dryness and 0.3 bar moisture content.
After a prolonged period in which evapotranspiration exceeded rainfall, 200
micro Ci of tritium were added with 100 liters of water to a plot 1.4 by
1.4 m. Replicated soil samples were taken after 24 hours and again 14 days
later. Tritiated water was not confined to surface layers, about half being
found below the 20-cm depth. Small amounts were found to the 100/cm sampling
depth. Tritiated water did not wet the surface layers to the 0.3 bar per-
centage. Water additions of 765 mm applied to an adjoining plot over a period
of 1 month showed gradual accumulation in the surface horizons of the profile
rather than wetting to field capacity in layers that wet from the soil sur-
face downward. These results are interpreted to indicate that water flowed
down fine cracks in A and B horizons as free water, some of it soaking
into the ped walls, or running into C horizon. This was confirmed by measure-
ments of the tritium concentration on crack walls. It was significantly
higher on ped surface in the Bva horizon than in soil taken from within the
peds.
72-73:02G-025
VERTICAL INFILTRATION INTO A LAYERED SOIL,
Aylor, D. E., and Parlange, J. V.
Connecticut Agricultural Experiment Station, New Haven, Department of Ecology.
Soil Science Society of America Proceedings, Vol. 37, No. 5, p 673-676, Septem-
ber-October 1973. 3 fig, 8 ref.
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Descriptors: *Infiltration, *Unsaturated flow, *Soil horizons, *Equations,
Anisotropy, Soil structure. Soil Physical properties. Mathematical studies,
Wetting, Saturated flow, Hydraulic conductivity.
An analytical model describes the soil moisture profiles for vertical infil-
tration into a layered soil (a fine textured layer over a coarser layer). For
the case of constant imposed flux of water at the surface, the effect of an
initial soil moisture content that increases with depth causes a steepening of
the moisture profile? and the effect of the discontinuity in soil texture at
the interface causes an accumulation of water above the interface in the fine
textured soil. The technique is easy to apply and gives results which are in
good agreement with experiment and substantially better than those obtained by
computer simulation.
72-73:020-026
EFFECTIVE AVAILABLE WATER AND ITS RELATION TO EVAPOTRANSPIRATION RATE, DEPTH
OF WETTING, AND SOIL TEXTURE,
Miller, D. E., and Aarstad, J. S.
Agricultural Research Service, Prosser, Washington.
Soil Science Society of America Proceedings, Vol. 37, No. 5, p 763-766, Septem-
ber-October 1973. 6 fig, 3 tab, 6 ref.
Descriptors: *Soil moisture, *Available water, *Evapotranspiration, Field
capacity, Moisture content, Drainage, Irrigation.
The effect of evapotranspiration (Et) rate on effective available water (EAW)
was evaluated for three soils ranging in texture from sand to silt loam, at
evapotranspiration rates of about 0.4 to 1.3 cm per day, and at two depths of
wetting. In all cases, as evapotranspiration rate increased, drainage follow-
ing irrigation decreased and as a result EAW increased. The increase in EAW
due to Et rate was relatively greater in the sand than in the finer textured
soils. If only midsummer Et rates are considered, EAW may be estimated quite
well from a field capacity test, provided soil depth and soil texture are
considered in determining the sampling time for characterizing field capacity.
If usable water is referenced to some safe depletion level rather than to
the 15-bar percentage, the effect of Et is more important. EAW is influenced
differently by depth of wetting in different textured soils.
72-73:020-027
DEEP PLOWING AND CHEMICAL AMENDMENT EFFECT ON A SODIC CLAYPAN SOIL,
Sandoval, F. M., Bond, J. J., and Reichman, G. A.
United States Department of Agriculture, Agricultural Research Service, Mandan,
North Dakota.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 4,
p 681-684, 687, July-August, 1972. 4 fig, 5 tab, 13 ref.
Descriptors: *Soil management, *Deep tillage, *Soil amendments. Crop production,
Cultivation, Soil properties, Soil chemistry, Soil profiles, Fallowing, Soils.
Deep plowing and chemical amendments improved a Solonetzic soil, increased
barley yields, and substantially increased wheat yields under the dryland
conditions of western North Dakota. The Rhoades silty clay loam, which had a
shallow dense sodic claypan, was plowed ititially to 6, 12, and 24-inch depths
with and without soil amendments. Split plots were alternately fallowed and
cropped for 5 years. Barley was grown 4 years and wheat on the 5th year. Crop
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yield increases attributed to deep plowing appeared to be associated with
greater soil water availability for crop use and for soil leaching. Soil
improvement was evidenced by the reduction of bulk densities and lessened
saline sodic soil conditions. Hardness of the soil crust was reduced by deep
plowing, and amendments further increased soil friability. The 5th year after
deep tillage and amendment treatments, spring wheat yields were 1,170, 1,570,
and 1,885 pounds per acre for the 6, 12, and 24-inch plowing depths, respec-
tively.
72-73:020-028
HYDRODYNAMICS OF BORDER IRRIGATION ADVANCE,
Kincaid, D. C., Heermann, D. F., and Kruse, E. G.
United States Department of Agriculture, Mitchell, Nebraska.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 4,
p 674-680, July-August, 1972. 14 fig, 1 tab, 10 ref.
(See 72-73:04A-007)
72-73:026-029
SPRINKLER PRECIPITATION GAGE ERRORS,
Kohl, R. A.
Snake River Conservation Research Center, Kimberly, Idaho.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 2,
p 264-265, 271, March-April, 1972. 2 fig, 1 tab, 7 ref.
Descriptors: *Irrigation practices, *Sprinkler irrigation, *Precipitation
gages, Uniformity coefficient, Evaporation control, Evaporation.
A number of different types of precipitation gages have been tried with sprink-
ler irrigation. The main problem encountered has been that of evaporation loss-
es from the container. Covering the water with oil had little effect since
much of the evaporation took place from droplets clinging to the walls above
the oil. A 250 millileter separatory funnel filled with oil was tested and
found to be quite successful. As the water enters the oil is displaced into
another container. The problem of splash losses does still exist with this
method.
72-73:020-030
PERFORMANCE OF A TILE DRAINAGE SYSTEM: AN EVALUATION OF A TILE DESIGN AND
MANAGEMENT,
Perrier, E. R., MacKenzie, A. J., Grass, L. B., and Shull, H. H.
United States Department of Agriculture, Agricultural Research Service, Urbana,
Illinois,
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 3,
p 440-444, May-June, 1972. 6 fig, 6 tab, 15 ref.
Descriptors: *Drainage, *Drainage effects, *Drainage practices, Drainage
systems, Subsurface drainage, Tiles, Drainage area. Drainage engineering,
Irrigation practices.
This study compared the steady and unsteady-state drainage relations measured
in the field to determine the performance and required management of an exist-
ing drainage system. The data were obtained from an 80 acre cotton field in
California's Imperial Valley. The soil is a Holtville silty clay loam highly
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stratified, typical of the area. Various drainage design equations were com-
pared to the measured data. Use of the tile lines for irrigation was also
investigated. Results indicate that all of the equations only approximate the
actual operation of the system. The use of the tile lines for irrigation
showed promise. Numerous conclusions and observations by the authors are
presented.
72-73:020-031
A LARGE, UNDISTURBED, WEIGHING LYSIMETER FOR GRASSLAND STUDIES,
Armijo, J. D., Twitchell, G. A., Burman, R. D., and Nunn, J. R.
Wyoming University, Agricultural Engineering Division, Laramie.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 5, p 827-830, September-October, 1972. 6 fig, 7 ref.
Descriptors: *Lysimeters, *Moisture meters, *Evapotranspiration, Moisture
content, Runoff, Water loss, Tunneling machines.
A large weighing type lysimeter was installed in the high plains of northeast-
ern Colorado. The unit consists of a steel tank 10 feet in diameter and 4
feet deep. The container is made of 1-inch thick steel plate. The unit rests
on a weighing mechanism consisting of a counter balance and electronic load
cells. The soil in the lysimeter is undisturbed with native vegetation. This
was accomplished using the tank as a large coring tube to cut out the undis-
turbed core. All of the related apparatus is placed underground except for a
small access manhole located 18 feet from the edge of the unit. Data collec-
tion has just begun. Total coat for the unit and installation was $51,000.
72-73Ğ02G-032
WHEAT AND GRAIN SORGHUM IRRIGATION IN A WIDE BED-FURROW SYSTEM,
Allen, R. R., and Musick, J. T.
United States Department of Agriculture, Agricultural Research Service, Bush-
land, Texas.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 1,
p 61-63, January-February, 1972. 1 tab, 4 fig, 7 ref.
Descriptors: Irrigation practices, *Furrow irrigation, Irrigation design,
Irrigation efficiency, Irrigation, Infiltration rates, Wheat, Grain sorghum,
Agricultural engineering.
Identifiers: Row crops, Wide-bed furrows.
A wide bed-furrow system was tested for irrigation of winter wheat and grain
sorghum on a slowly permeable clay loan in the Southern High Plains. The
system consisted of 60-inch spaced furrows separating relatively broad flat
beds about 40 inches wide. Wheel traffic zones were maintained along the
center of the beds separate from water furrows. The wide bed-furrow system
was compared with conventional 40-inch bed-furrows where wheel traffic occurs
in irrigation furrows. Beds and furrows were maintained in place during a
second crop by no-till seeding grain sorghum after wheat and using chemical
weed control. The wide bed-furrow system was successfully managed for produc-
tion of both winter wheat and grata sorghum. Yields from 60-inch bed-furrows
were similar to those from the 40-inch spacing. Water intake during irrigation
of wide bed-furrows on the 1,000-foot length of run was similar to 40-inch
conventional bed-furrows during a winter irrigation of wheat but averaging 23
percent less during three spring irrigations, and 19 percent less during two
seasonal irrigations of grain sorghum.
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72-73:020-033
DEVELOPMENT OF ASPHALT MOISTURE BARRIER EQUIPMENT,
Fischer, R. C.
International Harvester Company, Hinsdale, Illinois.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 4,
p 630-631, July-August, 1972. 2 fig, 6 ref.
Descriptors: *Soil moisture, *Asphalt, Linings, Soil asphalt, Moisture avail-
ability, Deep percolation, Groundwater movement, Root zone.
Identifiers: Moisture barrier.
Prototype equipment for installation of asphalt water barrier under sandy
farmland has attained rates of Ih acres per hour. Installation requires a
tractor of 200 horsepower and 1000 gallons of asphalt per acre. Predictions
show that some vegetable crops will return the installation price of $250
per acre within three years. While some corn areas have taken five years.
Asphalt barrier will conserve water and plant nutrients from leaching and
reduce stream pollution. Asphalt barrier may become a significant factor in
increasing the world food supply.
72-73:02G-034
NOTE ON THE INFILTRATION ADVANCE FRONT FROM BORDER IRRIGATION,
Parlange, J. Y.
Connecticut Agricultural Experiment Station, New Haven.
Water Resources Research, Vol. 9, No. 4, p 1075-1078, August 1973. 1 fig,
7 ref.
Descriptors: "Infiltration, *Border irrigation, Wetting, Soilwater movement,
Numerical analysis. Water spreading.
The spreading of a water layer of constant thickness over a near horizontal
soil surface is analyzed. The solution was applied consistently for short
times. It estimates gravity effects properly by taking into account the pres-
sure head of the water layer. An infiltration law valid for all times is also
suggested to obtain numerical solutions in practical cases.
72-73:020-035
A NUMERICAL AND SIMILARITY ANALYSIS OF INFILTRATION INTO CRUSTED SOILS,
Ahuja, L. R.
Purdue University, Lafayette, Indiana.
Water Resources Research, Vol. 9, No. 4, p 987-994, August 1973. 5 fig, 14
ref.
Descriptors: *Infiltration, *Soil water movement, *Surface sealing, "Impact
(Rainfall), Numerical analysis, Soil surfaces, Earth-water interfaces, Soil
compaction, Wetting, Unsaturated flow.
Identifiers: "Crusted soils, "Crusts.
One-dimensional, vertical infiltration of water through a crust of constant
nonzero hydraulic resistance is theoretically examined by using a numerical
solution and a similarity reduction of the problem. The soil-water content
at the crust-soil interface increases with time to approach a predictable final
steady water content asymptotically. A greater proportion of the flow takes
place at intermediate to low water contents, and without an appreciable effect
of gravity, as the crust resistance increases. For the water content at the!
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crust-soil interface, the cumulative infiltration, and the wet front progress,
simple expressions arise from the similarity reduction analysis, which is
based on specific functional forms of the soil-water diffusivity and suction
head, and a relatively small initial soil-water content. For early to inter-
mediate times of flow, the similarity analysis describes adequately the calcu-
lated numerical solution flow data for Yolo soil. For intermediate to large
times, a Green and Ampt type solution is linked to the similarity expression
for cumulative infiltration with fair success.
72-73:020-036
SIMULTANEOUS TRANSPORT OF SOLUTES AND WATER UNDER TRANSIENT UNSATURATED FLOW
CONDITIONS,
Bresler, E.
Volcani Institute of Agricultural Research, Bet-Dagan (Israel), Department of
Soil Physics.
Water Resources Research, Vol. 9, No. 4, p 975-986, August 1973. 5 fig, 22 ref.
Descriptors: *Unsaturated flow, *Unsteady flow, *Mass transfer, *Leaching,
*Solutes, Groundwater movement, Convection, Dispersion, Mixing, Aqueous solutions,
Path of pollutants, Numerical analysis, Finite element analysis.
Theoretical and mathematical tools are presented for analyzing transient one-
dimensional vertical simultaneous transfer of noninteracting solute and water
in unsaturated soils. The transient diffusion convection equation is solved
numerically by an approach that eliminates the effect of numerical dispersion.
The numerical results are compared with some analytical solutions for steady
water flow. For transient infiltration the results are compared with field
data. These comparisons indicate that the theory as well as the numerical
method is reliable and can be used with confidence. Results are given for
typical cases of infiltration, redistribution, and evaporation of water from
the soil and their effect on dispersion coefficients and salt concentration
profiles.
72-73:026-037
UNSTEADY RADIAL FLOW IN PARTIALLY SATURATED SOILS,
Fitzsimmons, D. W.
Idaho University, Agricultural Engineering Department, Moscow.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 5,
p 912-918, September-October, 1972. 9 fig, 1 tab, 13 ref.
Descriptors: *Groundwater movement, *Hydrology, *Capillary conductivity, Soil
moisture, Soil water, Groundwater, Moisture tension. Permeability, Soil physics,
Darceys law. Base flow.
A numerical model for simulating horizontal imbibition in a radially symmetric
flow system was developed. Unsteady radial flow from a cylindrical source
into a partially saturated soil was studied in the laboratory and with the
model to determine the effects of boundary and initial conditions on this
type, of flow. The model is based on the solution of the nonlinear partial
differential equation for unsteady radial flow. A predictor-corrector modifi-
cation of the Crank-Nicholson implicit difference method was used to solve the
equation subject to the appropriate boundary and initial conditions. Imbibition
was studied in the laboratory by allowing liquid to flow into a radially
symmetric, soil-filled flow system at pressures which were below atmospheric.
Tensiometers along the length of the flow system were used, in conjunction with
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a pressure transducer-indicator system, to measure the space-time distribution
of capillary pressure head in the flow system. A balance was used to monitor
the inflow during each test.
72-73:020-038
SELECTING A METHOD FOR SCHEDULING IRRIGATION, USING A SIMULATION MODEL,
LembXe, W. D., and Jones, B. A., Jr.
Illinois University, Urbana-Champaign.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 2,
p 284-286, March-April, 1972. 5 fig, 1 tab, 6 ref.
(See 72-73:04A-012)
72-73:026-039
EVALUATION OF A FURROW MODIFYIN6 DEVICE,
Gill, W. R.
United States Department of Agriculture, Agricultural Research Service, Auburn,
Alabama.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 3,
p 401-403, May-June, 1972. 5 fig, 3 tab, 2 ref.
Descriptors: *Soil treatment, Cultivation, *Soil management, Soil physics,
Soil texture, Soil properties.
Identifiers: *Plowing.
A study of the modification of a furrow slice indicates that a two-phase isola-
tion and shearing of the soil slice may reduce the draft of a plow in certain
soil conditions. The observed effect may be achieved by a reduction of compac-
tion hardening or a partial loosening of the slice. While the undercutting
and plowing of the slice may be done in separate operations it would appear
that they can be simultaneously undertaken in a single operation if suitable
space is provided between the tools. The forces on a plow may be beneficially
altered by varying the parameters of an integrally mounted undercutting device.
The use of a cutter reduces large lateral forces on plows.
72-73:026-040
APPLICATION OF MONTE CARLO METHOD TO SOIL WATER MOVEMENT,
Shih, S. F., and Kriz, G. J.
North Carolina State University, Biological and Agricultural Engineering
Department, Raleigh.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 5,
p 897-901, September-October, 1972. 5 fig, 4 tab, 8 ref.
Descriptors: *Soil water movement, *Soil physics, *Drainage, Porosity, Perme-
ability, Percolation, Darcey's law, Soil water, Soil moisture.
An approach for determining approximate solutions to problems of water movement
in soils called the Monte Carlo method was presented and demonstrated. The
basic concepts of the method are probability distribution, random number gener-
ations, and sampling techniques. The method was applied to solve problems of
steady state and transient flow with and without recharge. Solutions were
obtained directly by Monte Carlo techniques without analytically solving the
flow equation. Using the method of solution described in this study, the
hydraulic head or potential at any isolated point in the region can be obtained
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without solving for the hydraulic head or potential at the other mesh points.
Comparisons of results obtained using the Monte Carlo method were made with
values previously obtained by others. These comparisons indicate that the
method is applicable to problems of water movement in soils.
72-73:026-041
ESTIMATION PROCEDURES FOR RESPONSE FUNCTIONS OF CROPS TO SOIL WATER CONTENT AND
SALINITY,
Yaron, D., Bielorai, H., Shalhevet, J., and Gavish, Y.
Hebrew University, Agricultural Economics Department, Jerusalem, Israel.
Water Resources Research, Vol. 8, No. 2, p 291-300, April, 1972. 6 tab, 4 fig,
21 ref.
Descriptors: *Salinity, *Irrigation practices, *Crop response, *Soil-water-
plant relationships, Soil moisture, Soil chemistry. Crop production. Soil
environment. Soil management, Agricultural engineering.
The specification and estimation procedures of the response functions of crops
to soil water content and salinity are presented. The conceptual framework is
discussed, and the application of the suggested procedures is illustrated by
an analysis of two irrigation experiments. The possibility of positive correla-
tions between soil salinity, soil water content, and crop yield is discussed,
and possible erroneous evaluations of the effect of salinity on crop yield in
such situations are pointed out.
72-73:020-042
MEASUREMENT OF UNSATURATED HYDRAULIC CONDUCTIVITY BY THE CONSTANT OUTFLOW METHOD,
Overman, A. R., and West, H. M.
Florida University, Agricultural Engineering Department, Gainesville.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 6, p 1110-1111, November-December, 1972. 6 fig, 4 ref.
Descriptors: *Drainage engineering, *Soil physical properties, *Soil water
movement. Soil physics, Permeability, Percolation, Soil moisture, Drainage,
Drainage effects, Farm management.
Unsaturated hydraulic conductivity was calculated for Lakeland fine sand using
constant outflow from the bottom end of a column. Beginning at saturation,
hydraulic head was measured at several positions during drawdown. Water con-
tent was found to drop from 34.6 percent at saturation to approximately 11
percent and a corresponding tension of 60 cm. Drainage appears to continue
toward constant water content rather than toward the true equilibrium condition
of constant hydraulic head.
72-73:02G-043
WATER TABLE AND SOIL MOISTURE PROBABILITIES WITH TILE DRAINAGE,
Young, T. C., and Ligon, J. T.
Clemson University, Agricultural Engineering Department, Clemson, South Carolina.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 3,
p 448-451, May-June, 1972. 8 fig, 13 ref.
Descriptors: *Subsurface drainage, *Tile drainage, *Model studies. Mathematical
models. Computer models, Drainage, Drainage engineering, Closed conduits, South
Carolina.
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A method of soil moisture balance proposed by Ligon et al. (1965) was modified
to include surface runoff and checked against field data. The agreement of the
measured and computed data indicated that the soil moisture balance was adequate
for estimating soil moisture conditions and excess moisture. The transient-
flow equation development by van Schilfgaarde (1965) was verified with five
months field data from a field drainage laboratory. The excess moisture esti-
mated from the soil moisture balance was considered as the net accretion to
the water table. The soil moisture balance and the transient-flow equation were
combined in a computer model of the environment, soil and drainage system. An
average decrease of 1.67 percent of soil moisture in the upper 30 inches of
soil was found for a one-foot drop of the water table.
72-73:020-044
SUBSURFACE DISTRIBUTION OP NONUNIFORMLY APPLIED SURFACE WATERS,
Hart, W. E.
Colorado State University, Fort Collins, Colorado.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 4,
p 656-661, 666, July-August, 1972. 14 fig, 1 tab, 13 ref.
(See 72-73:04A-020)
72-73:020-045
TENSIOMETER-PRESSURE TRANSDUCER SYSTEM FOR STUDYING UNSTEADY FLOW THROUGH SOILS,
Fitzsimmons, D. W., and Young, N. C.
Idaho University, Agricultural Engineering Department, Moscow.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 2,
p 272-275, March-April, 1972. 6 fig, 10 ref.
Descriptors: *Soil moisture meters, *Tensiometers, *Soil water movement,
Moisture tension, Pressure measuring instruments. Unsteady flow, Unsaturated
flow, Soil water, Tension, Soil moisture, Irrigation.
A new, fast-acting system has been developed to nondestructively measure
moisture content of soil. The system is based on the old tensiometer technique
with two important changes. A tensiometer barrier material made of polyvinyl
chloride is used. This allows the water to pass to or from the soil much more
quickly than previous materials. Diaphragm-type pressure transducers which
have extremely small full-scale volumetric displacements provide much faster
readings. These units were used to investigate moisture movement. Descriptions
of technique and apparatus along with results are presented.
72-73:020-046
SHAPE FACTORS IN IRRIGATION WATER ADVANCE EQUATION,
Singh, P., and Chauhan, H. S.
Agricultural University, Agricultural Engineering Department, Pantnagar, Naini-
tal, India.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IRS, p 443-458, September, 1972. 10 fig, 1 tab, 9 ref.
Descriptors: *Irrigation practices, *Irrigation design, *Hydraulics, *Surface
irrigation. Flow, Irrigation engineering. Infiltration, Infiltration rates,
Soil mechanics. Soil physics. Irrigation.
Utilizing empirical advance and infiltration functions, relationships for sur-
79
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face and subsurface storage shape factors have been obtained. The surface and
subsurface shape factors as expressed by these relationships are functions of
time and infiltration characteristics of soil. Incorporating these relation-
ships, a continuity equation has been written for advance of water in surface
irrigation. The equation for advance of water compares well with field data
and relationships of other workers.
72-73:020-047
WATER-YIELD RELATIONS FOR NONFORAGE CROPS,
Downey, L. A.
New South Wales Department of Agriculture, Research Station, Leeton, Australia.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IRl, p 107-115, March, 1972. 3 fig, 13 ref.
Descriptors: *Irrigation practices, *Water distribution (applied), *Water
demand, *Water requirements, *Irrigation efficiency, Irrigation engineering,
Soil moisture, Cost-benefit ratios, Evapotranspiration, Grains (crops), Irriga-
tion, Water balance. Consumptive use.
Identifiers: Water deprivation, Agricultural products.
The relationship between soil moisture stress, evapotranspiration, and market-
able yield of crops - where the yield is a reproductive organ or associated
product - is examined. Under conditions of constant stress, yield is reduced
as a linear function of stress. Where stress is applied at different stages
in the development of the crop, no simple relationship exists. To predict
yield from the water available or from evapotranspiration, the severity of
stress and the physiological stage of development must be defined. A dispro-
portionate reduction in yield is induced by water stress during the phases of
reproduction corresponding to the period of peak evapotranspiration. Therefore,
if irrigation engineers cannot plan tbeir systems for times of peak demand,
cost-benefit analyses should reflect probable yield reductions.
72-73:026-048
RECYCLING AND RECOVERY OF NITROGEN, PHOSPHORUS, AND POTASSIUM BY COASTAL BER-
MUDAGRASS: II. UNDER GRAZING CONDITIONS WITH TWO STOCKING RATES,
Rouquette, F. M., Jr., Matocha, J. E., and Duble, R. L.
Texas A & M University, Overton.
Journal of Environmental Quality, Vol. 2, No. 1, p 129-132, January-March,
1973. 3 fig, 1 tab, 27 ref.
(See 72-73:05B-041)
72-73:020-049
RECYCLING AND RECOVERY OF NITROGEN, PHOSPHORUS, AND POTASSIUM BY COASTAL
BERMUDAGRASS: I. EFFECT OF SOURCES AND RATES OF NITROGEN UNDER A CLIPPING
SYSTEM,
Matocha, J. E., Rouquette, F. M., Jr., and Duble, R. L.
Texas A & M University, Overton.
Journal of Environmental Quality, Vol. 2, No. 1, p 125-129, January-March,
1973. 5 fig, 2 tab, 17 ref.
(See 72-73.-05B-042)
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72-73:02G-050
CHEMICAL DISTRIBUTION OF RESIDUAL FERTILIZER NITROGEN IN SOIL AS REVEALED BY
NITROGEN-15 STUDIES,
Allen, A. L., Stevenson, F. J., and Kurtz, L. T.
Langston University, Langston, Oklahoma.
Journal of Environmental Quality, Vol. 2, No. 1, p 120-124, January-March,
1973. 5 fig, 18 ref.
(See 72-73:058-043)
72-73:020-051
MOVEMENT OF NITRATE NITROGEN IN SOME GRASSLAND SOILS IN SOUTHERN ALBERTA,
Sommerfeldt, T. G., and Smith, A. D.
Canada Department of Agricultural Research Stations, Lethbridge, Alberta.
Journal of Environmental Quality, Vol. 2, No. 1, p 112-115, January-March,
1973. 5 fig, 3 tab, 14 ref.
(See 72-73:05B-044)
72-73:020-052
INCREASED DENITRIFICATION IN SOILS BY ADDITIONS OF SULFUR AS AN ENERGY SOURCE,
Mann, L. D., Focht, D. D., Joseph, H. A., and Stolzy, L. H.
California University, Riverside.
Journal of Environmental Quality, Vol. 1, No. 3, p 329-332, July-September,
1972. 1 fig, 6 tab, 18 ref.
(See 72-73:05B-049)
72-73:02G-053
NITRATE IN UNSATURATED ZONE OF AN ALLUVIAL SOIL IN RELATION TO FERTILIZER
NITROGEN RATE AND IRRIGATION LEVEL,
Adriano, D. C., Pratt, P. F., and Takatori, F. H.
California University, Riverside.
Journal of Environmental Quality, Vol. 1, No. 4, p 418-422, October-December,
1972. 5 fig, 3 tab, 10 ref.
(See 72-73:056-050)
72-73:020-054
CONCENTRATIONS OF NITROGEN, PHOSPHORUS, POTASSIUM, AND TOTAL SOLUBLE SALTS IN
SOIL SOLUTION SAMPLES FROM FERTILIZED AND UNFERTILIZED HISTOSOLS,
Hortenstine, C. C., and Forbes, R. B.
Florida University, Gainesville.
Journal of Environmental Quality, Vol. 1, No. 4, p 446-449, October-December,
1972. 5 fig, 9 ref.
(See 72-73:058-052)
72-73:020-055
DISTRIBUTION AND CHEMISTRY OF PHOSPHORUS IN AN ALBAQUALF SOIL AFTER 82 YEARS
OF PHOSPHATE FERTILIZATION,
Kao, C. W., and Blanchar, R. W.
Missouri Agricultural Experiment Station.
Journal of Environmental Quality, Vol. 2, No. 2, p 237-240, April-June, 1973,
81
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2 fig, 3 tab, 25 ref.
Descriptors: *Phosphates, *Fertilizers, *Leaching, Solubility, Nutrient
removal. Phosphorus, Soil chemistry. Chemicals, Dispersion.
The distribution of phosphorus in a fertilized and unfertilized Mexico silt
loam soil was measured. After 82 years of phosphorus fertilization, the added
phosphorus was found in Ap (0-23 cm), smaller amounts in the A and B, and B2
(23-86 cm), and large amounts in the B3 and upper C (86-137 cm) horizons.
In the fertilized soil the distribution of phosphorus, particularly inorganic
and available, was similar to that of original phosphorus in the soil profile.
The phosphorus adsorption capacities of fertilized and unfertilized soils
were similar. These data indicated that the soil fertilized with phosphorus
for 82 years had nearly double the total phosphorus content, but the ability
of the soil to adsorb additional phosphorus was the same. Ion products indi-
cated that the phosphorus level in the soil solution was controlled by the
solubility of stxengite.
72-73:020-056
SOIL CHANGES CAUSED BY EROSION CONTROL TREATMENTS ON A SALT DESERT AREA,
Wein, R. W., and West, N. E.
New Brunswick University, Fredericton, Department of Biology.
Soil Science Society of America, Proceedings, Vol. 37, No. 1, p 98-103, January-
February 1973. 2 fig, 3 tab, 26 ref.
Descriptors: *Soil investigations, *Saline soils, *Salt tolerance, *Soil water
movement, *Sedimentation rates, Utah, Colorado River Basin, Furrow irrigation,
Drainage engineering. Watersheds (basins). Bulk density, Desert plants, Deserts,
Plant physiology, Soil types. Erosion control.
Identifiers: Upper Colorado River Basin, Salt Desert.
The upper Colorado River Basin is comprised in part of 18 million acres of
Utah's erosion-prone watershed. Although this area contributes only 5 percent
of the water to the Colorado River, it contributes 44 percent of the sediment.
This has resulted in inadequate drainage due to the filling of reservoirs,
reducing storage capacity, and salt accumulation in the catchment basins of
gully plugs and furrows. A comparison of Chipeta Series soil and an unnamed
soil revealed that infiltration rates decreased in the Chipeta Series soil as
clay accumulated on the gully plug floor so that during rainstorms the water
supply was essentially sealed off from the subsoil, therefore evaporating into
an arid environment. The salt buildup caused by slow infiltration appears to
be inevitable. In the Chipeta Series soil, or in very saline soils, a salt
buildup could occur before the gully plugs fill with sediment to a level where
breaching occurs. The gully plug is essentially self destructive in soils
of saline-sodic nature because the short term increase in vigor and density of
native species is cancelled out by the loss of plants during construction and
during the return to status quo.
72-73:020-057
A LIMITING FLUX CONDITION IN INFILTRATION INTO HETEROGENEOUS POROUS MEDIA,
Watson, K. K., Perrens, S. J., and Whisler, F. D.
New South Wales University, Kensington, (Australia), Department of Civil
Engineering.
Soil Science Society of America Proceedings, Vol. 37, No. 1, p 6 - 10, January-
February 1973. 3 fig, 2 ref.
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Descriptors: *Infiltration, *Unsaturated flow, *Zone of aeration, *Porous med-
ia, Hydraulic conductivity, Soil water movement, Wetting, Equations, Hetero-
geneity.
Infiltration into a porous medium in which the hydraulic conductivity increases
with depth quickly approaches a limiting flux condition. This condition is
defined by a profile of pressure head which is tangential to the profile
water entry value. Equations are given to enable the values of the limiting
flux and the elevation of the point of contact to be calculated in terms of the
material properties and the boundary conditions. Below the limiting flux an
unsaturated zone exists, and wetting in this zone continues under the condition
of limiting flux. A method is given to determine the pressure and water
content profiles for this zone.
72-73:020-058
CHLORIDE MOVEMENT IN UNDISTURBED SWELLING CLAY SOIL,
Kissel, D. E., Ritchie, J. T., and Burnett, E.
Texas A & M University, College Station.
Soil Science Society of America Proceedings, Vol. 37, No. 1, p 21-24, January-
February 1973. 3 fig, 3 tab, 13 ref.
Descriptors: *Leaching, *Chlorides, *Expansive soils, *Expansive clays, *Pores,
Tracers, Fluorescent dye, Adsorption, Ion exchange, Dispersion, Percolation,
Soil water movement, Salts, Soil structure, Porosity, Permeability, Hydraulic
conductivity.
Downward leaching of Cl followed large, continuous soil pores in saturated,
swelling clay soils. Using water-soluble fluorescein as a tracer, distinct
small areas of the soil contained fiuorescenin, whereas nearby areas contained
no visible fluorescein after water with Cl and fluorescein was ponded at the
surface for 1.5 days. Breakthrough curves of a large saturated core of undis-
turbed swelling clay soil indicated that Cl was moving quite rapidly through
large connected pores. In the undisturbed swelling clay soil, the volume of
soil water not containing Cl was about 60%; when the disturbed soil was
repacked to the same density this value decreased to 40%. More of the original
soil solution was eluted from long undisturbed cores than from short undisturbed
cores of the same diameter before Cl appeared in the effluent. The longer
core wall blocked more connected flow paths which were not vertical.
72-73:020-059
INFLUENCE OF WATER CONTENT ON ELECTRICAL CONDUCTIVITY OF THE SOIL,
Gupta, S. C., and Hanks, R. J.
Utah State University, Logan, Department of Soil Science and Biometeorology.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 855-857, Novem-
ber-December 1972. 3 fig, 2 tab, 6 ref.
Descriptors: *Electrical studies, *Soil water, *Salinity, *Soil moisture
meters, Mass transfer. Electrical conductance, Conductivity, Geophysics,
Moisture content.
The four-probe system of measuring electrical conductivity of soil eliminates
the time lag error, but introduces the problem of correcting the changes in
conductivity caused by water content. Regression equations developed to esti-
mate saturation of 1:5 extract electrical conductivity from four-probe conduc-
tivity and water content gave correlation coefficients of 0.75 and 0.90, respec-
tively. Correlations for individual soils were generally higher than the
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combined soils. The regression equation relating the ratio of four-probe
conductivity to four-probe conductivity at saturation with water content yields
a correlation coefficient of 0.88 for the combined soil data.
72-73:020-060
HORIZONTAL INFILTRATION INTO LAYERED SOILS,
Reichardt, K., Nielsen, D. R., and Biggar, J. W.
California University, Davis, Department of Water Science and Engineering.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 858-863, Novem-
ber-December 1972. 10 fig, 1 tab, 11 ref.
Descriptors: *Infiltration, *Soil water movement, Percolation, Diffusivity,
Wetting, Hydraulic conductivity, Stratification, Numerical analysis. Soil
physical properties.
Identifiers: *Infiltration (Horizontal).
A numerical solution of the soil water movement equation is presented for
horizontal infiltration into air-dry layered soils. The solution is based
upon a scaled soil water diffusivity function common to six homogeneous soils
and values of the microscopic characteristic length ascertained for each soil
from homogeneous columns. Soil water content distributions and cumulative
infiltration for differeat sequences of soil layers are analyzed. Agreement
between experimental and theoretical infiltration profiles suggests a convenient
means to study the influence of texture and hydraulic characteristics of differ-
ent layers on the infiltration process.
72-73:020-061
SOLUTIONS FOR MISCIBLE DISPLACEMENT OF SOIL WATER WITH TIME-DEPENDENT VELOCITY
AND DISPERSION COEFFICIENTS,
Warrick, A. W., Kichen, J. H., and Thames, J. L.
Arizona University, Tucson, Department of Soils, Water and Engineering.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 863-867,
November-December 1972. 3 fig, 2 tab, 12 ref.
Descriptors: *Infiltration, *Ion transport, *Mass transfer, *Soil water
movement, Dispersion, Mixing, Aqueous solutions, Path of pollutants, Unsaturated
flow, Percolation.
Miscible displacement processes with time-varying velocity and dispersion
coefficients are examined. Simplified solutions utilizing arbitrary initial
conditions are presented and used to simulate step and slug inputs of solutes
into soil during infiltration of water. The solutions are used in the analysis
of experimental data, both for field infiltration with a slug of solute and for
psychrometric measurements of salt fronts in a laboratory sand column. Experi-
mental data obtained for solute movement were more accurately described using
time-increasing dispersion relationships than for constant values.
72-73:020-062
THE NUMERICAL ANALYSIS OF INFILTRATION INTO HETEROGENEOUS POROUS MEDIA,
Whisler, F. D., Watson, K. K., and Perrens, S. J.
Agricultural Research Service, Phoenix, Arizona, Water Conservation Laboratory.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 868-874, Novem-
ber-December 1972. 10 fig, 7 ref.
84
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Descriptors: *Infiltration, *Soil water movement, *Water spreading, Recharge,
Numerical analysis, Hydraulic conductivity, Porous media, Unsaturated flow,
Saturated flow.
Identifiers: Ponded infiltration.
Ponded infiltration into a heterogeneous porous medium was studied using a
numerical solution of the flow equation. The medium was assumed to exhibit
scale heterogeneity, the heterogeneity being specifically defined in terms of
a linear variation of the resaturated hydraulic conductivity with depth. The
spatial variation of the hydrologic characteristics was initially defined in
terms of the water entry value of the medium at the point in question and an
empirical relationship between the water entry value and the resaturated hydrau-
lic conductivity. Pressure head and water content profiles were obtained for
two hydraulic conductivity distributions and compared with that for a homogen-
eous soil having an average conductivity. The profiles reveal distinct regions
that are different from the uniform case depending on whether the conductivity
is increasing or decreasing with depth.
72-73:020-063
WATER MOVEMENT IN UNDISTURBED SWELLING CLAY SOIL,
Ritchie, J. T., Kissel, D. E., and Burnett, E.
Agricultural Research Service, College Station, Texas.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 874-879, Novem-
ber-December 1972. 5 fig, 1 tab, 8 ref.
Descriptors: *Soil water movement, *Expansive soils, *Expansive clays, *Prac-
ture permeability, Cracks, Laboratory tests, Tracers, Dye releases, Hydraulic
conductivity.
Hydraulic conductivities of Houston Black clay were measured in two field
basins, in relatively large undisturbed cores, and in small disturbed cores.
Conductivities averaged about 2.5 cm/day for the field basins but were about
10 times less for the core samples. Using water tagged with fluorescein to
displace deionized water in an undisturbed core, pores in distinctive isolated
areas were found to be conducting most of the water. Water contained within
structural units appeared to be inactive in the flow process when compared to
water flow around the units.
72-73:020-064
SOIL AIR PRESSURE AND WATER INFILTRATION UNDER BORDER IRRIGATION,
Dixon, R. M., and Linden, D. R.
Agricultural Research Service, Reno, Nevada.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 948-953, Novem-
ber-December 1972. 7 fig, 11 ref.
Descriptors: *Infiltration, *Border irrigation, *Edge effect, *Soil water move-
ment, Wetting, Pressure, Mixing, Hydraulic conductivity, Pores, Interstices.
Identifiers: *Soil air displacement, *Soil air pressure.
Soil air pressure and water infiltration were measured during actual and simu-
lated border irrigation of a uniform loam soil having a water table about 2 m
beneath the surface. Displaced air pressure decreased downslope and across
slope from center to edge of the border strips. A maximum displaced air
pressure of 21 cm of water was observed in the upslope central part of the
border strip. Air entrapment commonly occurred at a 50-cm depth next to
85
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border dikes but rarely occurred midway between dikes, which implies that
water penetration was greatest in the region of lowest displaced air pressure.
Displaced air pressure, building to a maximum of about 19 cm, reduced total
infiltration by about one-third. Such pressure appears to impede infiltration
mainly by preventing or retarding direct flow of surface water into and within
open macropores. In the central region of the border strip where displaced
air pressure exceeds the surface water head, macropores vent displaced soil
air upward; whereas along the border dikes where surface head exceeds air
pressure, macropores conduct free surface water downward. Soil air pressure
and its infiltration effects are not negligible as is commonly assumed by
Darcy-based flow theory, and soil air can be a useful tool for controlling
infiltration in some important situations.
72-73:020-065
LONG-TERM EFFECTS OF MANURE, FERTILIZER, AND PLOW DEPTH ON CHEMICAL PROPERTIES
OF SOILS AND NUTRIENT MOVEMENT IN A MONOCULTURE CORN SYSTEM,
Vitosh, M. L., Davis, J. F., and Knezek, B. D.
Michigan Agricultural Experiment Station, East Lansing.
Journal of Environmental Quality, Vol. 2, No. 2, p 296-299, April-June, 1973.
5 tab, 20 ref.
(See 72-73:05B-057)
72-73:020-066
NITROGEN LOSSES IN SURFACE RUNOFF FROM AGRICULTURAL WATERSHEDS ON MISSOURI
VALLEY LOESS,
Schuman, G. E., Burwell, R. E., Piest, R. F., and Sportier, R. G.
United States Department of Agriculture, Lincoln, Nebraska.
Journal of Environmental Quality, Vol. 2, No. 2, p 299-302, April-June, 1973.
5 tab, 15 ref.
(See 72-73:056-058)
72-73:020-067
THEORY, DEVELOPMENT, AND UTILIZATION POTENTIAL OF THE BIOMILIEU CONCEPT,
Szekelyhidi, I. J.
Department of Army, Corps of Engineers, Chicago, Illinois.
Water Resources Bulletin, Vol. 8, No. 1, p 24-37, February, 1972. 11 fig, 6
ref.
Descriptors: *Bioindicators, *Biorhythms, *Ecology, Soil, Management, Environ-
ment, Biological communities, Computers, Computer models, Cost-benefit analysis.
Identifiers: *Biomilieu Theory, *Biomilieu index, Environmental quality
index, Biocatalytic.
A quantitive engineering approach to analysis of total environment allowing for
simultaneous consideration of a theoretically infinite number of quality
indicators and physiological requirements is presented. Theory and fundamen-
tals of a two-dimensional space and time function solution concerning a small
estuarine-type environment is discussed. A three-dimensional solution is
indicated. Input data may range from reconnaissance-type to the outputs of
mathematical transport models. Applications are discussed with respect to
environmental quality problems, availability of suitable data, and some areas
of research where results could find immediate application.
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72-73:020-068
THE PERSISTENCE AND MOVEMENT OF PICLORAM AND 2, 4, 5-T IN SOILS,
Lutz, J. P., Byers, G. E., and Sheets, T. J.
North Carolina State University, Raleigh.
Journal of Environmental Quality, Vol. 2, No. 4, p 485-488, October-December,
1973. 1 fig, 5 tab, 24 ref.
(See 72-73:05B-065)
72-73:020-069
FUNCTIONS TO PREDICT EFFECTS OF CROP WATER DEFICITS,
Stewart, J. I., and Hagan, R. M.
California University, Davis.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR4, p 421-439, December, 1973. 4 fig, 38 ref.
(See 72-73:03F-046)
72-73:020-070
APPROXIMATE SOLUTION FOR UNCONFINED SEEPAGE,
Desai, C. S.
United States Army Engineer Division, Vicksburg, Mississippi.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IRl, p 71-87, March,1973. 12 fig, 24 ref.
(See 72-73:02F-069)
72-73:020-071
SIMULATION OF POST-IRRIGATION MOISTURE MOVEMENT,
Molz, F. J.
Auburn University, Civil Engineering Department, Auburn, Alabama.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR4, p 523-532, December, 1972. 9 fig, 1 tab, 12 ref.
Descriptors: *Irrigation, *Soil-water-plant relationships, *Soil water movement,
*Drainage, Soil water. Root zone, Darcey's law, Mathematical models. Computer
models, Root systems, Transpiration, Water loss.
Transpiration-induced moisture removal by the plant roots is represented by a
negative source term in the Darcy equation. When soil is wetted to near satur-
ation, moisture flow is initially downward due to gravity. As transpiration
dries the upper soil layers, capillary suction reverses the Darcian flow.
Upward water flux through soil has a maximum which occurs high in the root
zone initially and gradually moves downward. Throughout much of time periods
studied there was downward flow in portions of the soil-root system. Very
little water, if any, was obtained by the plants from below the root zone, but
considerable moisture was often lost to this region. As the soil-root system
dries, a point is reached at which the Darcian moisture flux in soil can be
neglected and the moisture removal process described by local extraction alone.
When this occurs, the root geometry assumes major importance in determining
the water supply available to a plant.
72-73:020-072
PREFABRICATED FILTER-FIN FOR SUBSURFACE DRAINS,
Healy, K. A., and Long, R. P.
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Connecticut University, civil Engineering Department, Storrs.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR4, p 543-552, December, 1972. 5 fig, 1 tab, 5 ref.
Descriptors: *Drainage, *Drainage practices, Drainage systems, "Filters,
Drainage engineering, Tile drainage, Subsurface drainage, Drains, Filtration,
Seepage, Slope stabilization.
Identifiers: Fins, Underdrains.
The design and methods of installation of a prefabricated filter media for use
with subsurface drains is presented. The filter media is fabricated from
synthetic materials and can be used without special backfill. Methods of
installing the prefabricated system in trenches and slopes are described.
Results are presented from five field test installations comtaining a total
length of 2,500 feet (762 m) of prefabricated underdrain. Costs for the under-
drains are shown, and potential economics for slope stabilization and land
drainage are indicated.
72-73:026-073
PROBLEMS OF CHOOSING IRRIGATION TECHNIQUES IN A DEVELOPING COUNTRY,
Soltani-Mohammadi, G. R.
Pahlavi University, Shiraz, Iran.
Water Resources Research, Vol. 8, No. 1, p 1-6, February, 1972. 4 tab, 13 ref.
(See 72-73:04A-029)
72-73:02G-074
PERIODIC CHANGES IN THE IONIC CONCENTRATIONS OF SOME SUBMERGED SOILS OF BIHAR,
Biswas, D., Naphade, J. D., and Dhua, S. P.
Fertilizer Corporation of India, Sindri.
Agronomy Journal, Vol. 64, No. 3, p 336-338, 1972. Illus.
Identifiers: *Soil chemical properties. Ammonium, *Bihar (India), Carbonates,
Chlorides, Fertilizers, Ions, Minerals, Oryza sativa M, Rice, Soils, Submerged
soils.
The investigation was carried out under laboratory conditions to study the
chemistry of submerged soils of Bihar to help in assessing their potentialities
in meeting the nutritional requirements of the rice plant (Orza sativa L.).
The soils were kept at 1:1.5 soiliwater ratio and analyzed periodically for
pH, electrical conductivity, soluble NH4+, Fe-H-, Mn++, P, Na+, K+, Ca++, CO3+.,
HCO3-, and Cl- on the 15th, 30th, 45th, and 60th day. The results show differ-
ential release of these nutrients in different soils with time. While the pH
of acidic soils increased, that of alkaline soils decreased with the time of
submergence. The pH of all soils fell between 6.50 and 8.50 on the 60th day.
In general the peak values of Mn-HH- and CO3ħ were noted on the 15th day,
HCO3- and Cl- on the 30th day, and that of NH4+ between the 30th and 45th day
after submergence. Most of the soils appear to be inherently deficient in
N, P, K, Fe++, etc. and a good response of rice to fertilizer applications may
be expected.
72-73:026-075
EFFECT OF SOIL AIR MOVEMENT AND COMPRESSIBILITY ON INFILTRATION RATES,
LeVan Phuc, and Morel-Seytoux, H. J.
Colorado State University, Fort Collins, Department of Civil Engineering.
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Soil Science Society of America Proceedings, Vol. 36, No. 2, p 237-241, March-
April 1972. 7 fig, 15 ref.
Descriptors: *Infiltration, *Unsaturated flow, *Permeability, *Wetting, *Soil
water movement, Hydraulic conductivity, Zone of aeration.
Identifiers: *Multiphase flow, Soil air displacement
Air flow and compressibility may affect significantly the infiltration rates
and the saturation profiles of soils. When water infiltrates the soil, the
air in the soil pores is pushed aside to make room for the water. With a
lower no-flow boundary, air can only escape at the top, but its flow is impeded
by water entering the soil. In the unsaturated (one-phase) flow theory two
physical effects both of which tend to reduce infiltration are neglected,
namely, the viscous resistance to airflow and the air compression ahead of the
wetting front. Thus the two-phase flow theory, which includes these two
effects, will necessarily predict lower infiltration rates than the unsaturated
flow theory. So the infiltration curve for the semi-infinite medium calculated
by the two-phase flow theory must, of necessity, lie below the curve that
would be predicted by the unsaturated (one-phase) flow theory. In numerical
experiments, the wetting front never reached the lower boundary during the
infiltration stage. The saturation profiles near the surface indicate a clear
shift toward a drier state to allow air to escape, thereby reducing the capacity
of the soil to imbibe water.
72-73:020-076
ON THE CALCULATION OF HYDRAULIC CONDUCTIVITY,
Jackson, R. D.
Agriculture Research Service, Phoenix, Arizona, Water Conservation Laboratory.
Soil Science Society of America Proceedings, Vol. 36, No. 2, p 380-382, March-
April 1972. 2 fig, 1 tab, 12 ref.
Descriptors: *Hydraulic conductivity, *Unsaturated flow, *Soil water movement,
Moisture content, Statistical methods, Laboratory tests.
Methods for calculating hydraulic conductivities of porous materials proposed
by Marshall and by Millington and Quirk are similar except for the pore inter-
action term. This term is constant in the Marchall method. Equations for the
two methods differ only by the exponent of the pore interaction term, which is
0 for Marshall's method and 4/3 for Millington and Quirk's. Data for four
porous materials, for which the hydraulic conductivities, pressure heads, and
water contents were determined on the same sample, were used in a statistical
procedure to obtain a best fit value for the exponent. An exponent of 1
adequately predicted the measured conductivities. With this exponent, hydraulic
conductivities for a field soil were calculated from a laboratory-determined
pressure head-water content relation. Calculated and measured conductivities
agreed to within the limits of error of measurement.
72-73:02G-077
SOLUBILITY AND SOLUBILITY PRODUCT OF GYPSUM IN SOIL SOLUTIONS AND OTHER AQUEOUS
SOLUTIONS,
Bennett, A. C., and Adams, F.
Auburn University, Alabama, Department of Agronomy and Soils.
Soil Science Society of America Proceedings, Vol. 36, No. 2, p 288-291, March-
April 1972. 2 fig, 3 tab, 10 ref.
Descriptors: *Gypsum, *Solubility, *Water chemistry, Sulfates, *Soil water,
89
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Solutes, Chemical potential, Soil chemistry, Aqueous solutions. Electrolytes.
Identifiers: *Solubility product (Gypsum), *Soil solutions.
The solubility of gypsum was measured in several soils and dilute aqueous
electrolytic media. The ionic strength of electrolytic media ranged from
0.059 to 0.314; the solubility product of gypsum in these solutions ranged
from 0.0000213 to 0.0000279 and averaged 0.0000251. In soil solutions, the
solubility product of gypsum ranged from 0.0000241 to 0.0000292 and averaged
0.0000273. The solubility product of gypsum in pure water was 0.0000258.
The mean ionic activity coefficient of gypsum in solutions of different ionic
strengths was computed using analytical data from aqueous electrolytic media
and the known solubility product. The plot of this mean ionic activity coeffic-
ient versus the square root of gross solution ionic strength allowed accurate
determination of the solubility product of gypsum in soil solutions using only
analytical data.
72-73:020-078
STEADY INFILTRATION FROM BURIED, SURFACE, AND PERCHED POINT AND LINE SOURCES IN
HETEROGENEOUS SOILS: 1. ANALYSIS,
Philip, J. R.
Commonwealth Scientific and Industrial Research Organization, Canberra (Austra-
lia), Division of Environmental Mechanics.
Soil Science Society of America Proceedings, Vol. 36, No. 2, p 268-273, March-
April 1972. 11 ref.
Descriptors: ^Infiltration, *Steady flow, *Irrigation water, *Subsurface
irrigation, *Soil water movement, Porous media. Soil moisture, Unsaturated
flow, Numerical analysis, Hydraulic conductivity.
Identifiers: *Steady infiltration.
The quasilinearized steady infiltration equation is generalized to apply to
heterogeneous soils with conductivity depending exponentially on botb^moisture
potential and depth. Mathematical developments, including a theorem connecting
surface and buried source solutions, follow closely those established previously
for homogeneous soils. Solutions are found for buried, surface, and perched
point and line sources. Physically relevant solutions are limited to the follow-
ing ranges of the dimensionless coefficient of dependence of conductivity on
depth: for buried and surface sources, zero or larger; for perched point sources,
-1 or smaller; for perched line sources, greater than -1. The homogeneous
medium with the zero coefficient is an extreme case for existence of buried
and surface source solutions. Perched source solutions (relevant to subirri-
gation) exist only for soils with conductivity increasing rapidly with height
above the impermeable base.
72-73:020-079
INSTRUMENTATION EFFECTS ON ERRORS IN NUCLEAR METHODS FOR SOIL WATER AND DENSITY
DETERMINATION,
Stone, J. F.
Oklahoma Sate University, Stillwater, Department of Agronomy.
Soil Science Society of America Proceedings, Vol. 36, No. 2, p 261-264, March-
April 1972. 10 ref.
Descriptors: "Calibrations, *Nuclear moisture meters, *Instrumentation, *Soil
moisture meters. Moisture meters, Nuclear meters, Soil water, Radioactivity
techniques, Density.
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Equations for calculating the errors of determination of the ratio commonly
used in soil moisture determination by neutron scattering are discussed. Some
of the errors due to random event counting, dead time, and drift phenomena
not fully compensated for by the ratio method are held to 0 at the point where
the count in the soil medium is equal to the count in the standard. It is
recommended that this point appear above the center of the calibration curve.
72-73:020-080
NUMERICAL ANALYSIS OF DRAINAGE OF A HETEROGENEOUS POROUS MEDIUM
Watson, K. K., and Whisler, F. D.
Agricultural Research Service, Phoenix, Arizona, Water Conservation Laboratory.
Soil Science Society of America Proceedings, Vol. 36, No. 2, p 251-256, March-
April 1972. 11 fig, 1 tab, 14 ref.
Descriptors: *Soil water movement, *Drainage, *Numerical analysis, Percolation,
Mathematical models, Unsaturated flow. Hydraulic conductivity, Seepage, Pressure
head.
Identifiers: Gravity drainage.
Gravity drainage of a heterogeneous porous medium was analyzed using a numerical
solution of the flow equation. The medium was assumed to exhibit scale hetero-
geneity, specifically defined in terms of a linear variation of the saturated
hydraulic conductivity with depth. Within the restrictions imposed by scale
heterogeneity, the hydrologic characteristics were chosen so that their form
represented real data. The spatial variation of the hydrologic characteristics
was initially defined in terms of the air entry value of the medium and an
empirical relationship between the air entry value and the saturated hydraulic
conductivity. Pressure head and water content profiles were computed for three
hydraulic conductivity distributions in which the conductivity decreased with
depth. The pressure head profiles for these distributions show zones of
positive pressures and the slow decay of these pressures during drainage.
72-73:020-081
SOURCE-DETECTOR GEOMETRY EFFECT ON NEUTRON PROBE CALIBRATION,
McCauley, G. N., and Stone, J. F.
Oklahoma State University, Stillwater, Department of Agronomy.
Soil Science Society of America Proceedings, Vol. 36, No. 2, p 246-250, March-
April, 1972. 3 fig, 6 ref.
Descriptors: "Calibrations, *Nuclear moisture meters, "Instrumentation, *Soil
moisture meters, Moisture meters, Nuclear meters, Soil water.
Identifiers: "Neutron detectors.
The midpoint of the anode wire and the center of the sensitive volume of a boron
tirfluoride neutron detector tube coincide and should be expected to do so
for all such detector tubes of symmetrical construction. The effect of position
of the neutron source on the count rate in hydrogenous media was studied. Four
hydrogenous media were used: urea, aluminum sulphate, water, and the paraffin
shield for the probe. Second-degree curves fit the data of count rate vs.
distance between source and reference point. The center of the sensitive
volume coincided with the point of greatest count rate. The center was also
the position for greatest sensitivity to water content. Changes of source
position as small as 0.5 cm from the position at original calibration will
significantly change the calibration curve. Users can detect such changes
by monitoring ratios of readings in two different hydrogenous media in the
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laboratory. Any such change in source-detector geometry will produce a change
in ratio. Positional changes may be the result of either a source movement
or replacement of detector tube with one of different dimension.
72-73s02G-082
SCALING OF HORIZONTAL INFILTRATION INTO HOMOGENEOUS SOILS,
Reichardt, K., Nielsen, D. R., and Biggar, J.W.
California University, Davis, Department of Water Science and Engineering.
Soil Science Society of America Proceedings, Vol. 36, No. 2, p 241-245, March-
April 1972. 9 fig, 1 tab, 8 ref.
Descriptors: *Infiltration, *Soil water movement, *Diffusion. Wetting, Hydrau-
lic similitude, Diffusivity, Hydraulic conductivity. Percolation, Soil proper-
ties, Porous media. Numerical analysis, Regression analysis.
Identifiers: Similar media.
Horizontal infiltration of water into uniform air-dry soil columns was examined
experimentally and theoretically. The applicability of the similar-media
concept to the scaling of soils having a wide textural range is studied. The
microscopic characteristic length may be determined from plots of the distance
to the wetting front as a function of the square root of time. These plots
coalasce into one line when expressed in terms of scaled coordinates. If the
soil-water diffusivity of one soil is known, values of the microscopic charac-
teristic length can be used to estimate the soil-water diffusivity of the other
soils.
72-73:026-083
APPROXIMATION OF FIELD HYDRAULIC CONDUCTIVITY BY LABORATORY PROCEDURES ON
INTACT CORES,
Roulier, M. H., Stolzy, L. H., Letey, J., and Weeks, L. V.
California University, Riverside, Department of Soil Science and Agricultural
Engineering.
Soil Science Society of America Proceedings, Vol. 36, No. 3, p 387-393, May-
June 1972. 7 fig, 1 tab, 17 ref.
Descriptors: *Hydraulic conductivity, *Laboratory tests, *Soil water movement,
Computer programs, Sampling, Cores, Unsteady flow. Soil moisture, Unsaturated
flow.
Several laboratory procedures for approximating field values of unsaturated
hydraulic conductivity over the suction range 30 to 100 cm of water were
studied. Conductivity was measured in the laboratory on 10- by 30-cm intact
cores by the transient flow (TF) method and was calculated by both the Marshall
(M) equation and Millington and Quirk (M and Q) equation using moisture charac-
teristic curves from laboratory measurements on intact cores and from the field
data. The TF values were all higher than field values but, when used with a
matching factor, they satisfactorily approximated field conductivities. The
method of calculating the flow velocity influenced the results. The best
results were obtained from a computer program which used a numerical different-
iation subroutine. When used with matching factors, conductivities calculated
by the M equation and M and Q equation were good approximations of field
conductivity, though less satisfactory than results from the TF computer
calculations. The best M and Q values were calculated from a field moisture
characteristic while the M values were satisfactory when calculated either
from the field moisture characteristic or from one measured in the laboratory
on intact 6 by 10-cm cores.
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72-73 .-02G-084
SYSTEMATIC AND RANDOM ERRORS IN DUAL GAMMA ENERGY SOIL BULK DENSITY AND WATER
CONTENT MEASUREMENTS,
Gardner, W.H., Campbell, G.S., and Calissendorff, C.
Washington State University, Pullman, Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 36, No. 3, p 393-398, May-
June 1972. 5 fig,. 2 tab, 18 ref.
Descriptors: *Soil density probes, *Soil moisture meters, *Nuclear moisture
meters, *Bulk density, Gamma rays. Calibrations, Instrumentation, Nuclear
meters, Soil density, Radioactivity techniques.
Soil bulk density and water content may be obtained concurrently through
measurement of the attenuation of gamma photons from two different gamma ray
sources and simultaneous solution of the resulting attenuation equations.
Using gamma photons from Am-241 at 0.060 Mev and from Cs-137 at 0.662 Mev,
attenuated in 10-cm soil columns, the standard deviation in both water content
and bulk density measurements is primarily due to random emission and is about
0.007 g/cc for 1 million counts measured in air and about 0.005 g/cc for 2.5
million counts. However, as larger counts are used the precision of measure-
ment of column thickness and soil and water attenuation coefficients becomes
limiting. Maximum precision is about 0.0035 g/cc at midrange values of water
content and bulk density. For narrow collimating slits the spatial resolution
is only a little greater than slit thickness.
72-73.-02G-085
STEADY INFILTRATION FROM SOURCES AT ARBITRARY DEPTH,
Raats, P. A. C.
Agricultural Research Service, Madison, Wisconsin, Soil and Water Conservation
Research Division.
Soil Science Society of America Proceedings, Vol. 36, No. 3, p 399-401, May-
June 1972. 8 ref.
Steady infiltration is discussed, based on the assumption that the hydraulic
conductivity is an exponential function of the pressure head. The solution for
infiltration from a single point source at arbitrary depth is presented. On
the basis of this solution, a superposition theorem for surface sources is
generalized to an arbitrary distribution of sources at arbitrary depths. Gener-
al expressions for the pressure head, the total head, and the components of the
flux are also given.
72-73:020-086
RELATIVE FLOW RATES OF SALT AND WATER IN SOIL,
Krupp, H. K., Biggar, J. W., and Nielsen, D. R.
California University, Davis, Department of Water Science.
Soil Science Society of America Proceedings, Vol. 36, No. 3, p 412-417, May-
June 1972. 6 fig, 2 tab, 21 ref.
Descriptors: *Soil water movement, *Ion transport, *Tracers, Salts, Tritium,
Chlorides, Dispersion, Mixing, Diffusion, Saline water-freshwater interfaces,
Leaching, Translocation, Seepage, Adsorption-
Identifiers: Miscible displacement.
A hydrodynamic equation for the mixing of two miscible solutions in porous
media was combined with the Gouy theory for ion distribution in soil pores in
93
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order to examine the effect of flow velocity and ion distribution in the pores
on the breakthrough curves. The model considers zones of mobile and immobile
solution in the porous media, and the extent these zones are affected by the
total concentration of the solution and the pore water velocity. Miscible
displacement experiments of Cl-36 and tritium through Panoche clay loam at
0.1, 0.01, and 0.001N total salt concentration using CaC12 were performed on
the same column at a fast and slow flow velocity. The exclusion volume for
isotope and the separation volume for Cl-36 and tritium increased as flow
velocity decreased, and these changes are related to the total ion concentra-
tion, the thickness of the diffuse double layer, and the zones of mobile and
immobile solution.
72-73:026-087
SALT AND WATER MOVEMENT JN UNSATURATED FROZEN SOIL
Gary, J. W., and May land, H. F.
Agricultural Research Service, Kimberly, Idaho, Snake River Research Center.
Soil Science Society of America Proceedings, Vol. 36, No. 4, p 549-555, July-
August 1972. 6 fig, 1 tab, 16 ref.
Descriptors: *Diffusion, *Saline water, *Soil water movement, *Frost heaving,
*Frozen soils. Leaching, Ion transport. Mass transfer, Ice, Frost, Freezing,
Brines, Salinity, Unsaturated flow.
Identifiers: *Thermal diffusion, *Salt diffusion.
Salt and water movements were measured in unsaturated frozen soil columns
incubated under a thermal gradient for 3, 6 or 9 weeks. Both water and
salt moved from the warmer to cooler areas in the soil, creating a twofold
concentration difference over a 24-cm distance. Movements of CaCl2, Lil, and
K2S04 were affected by cation exchange reactions and salt solubilities at high
concentrations. Although mass flow of dissolved salts in a liquid film of
water was the principal transfer mechanism, both vapor and salt diffusion
were sometimes significant. Thermal diffusion and salt sieving did not appear
to be important. Because the vapor pressure of ice controls the water potential
in frozen soil, the amount of unfrozen water and the matric suction could be
calculated from a water release curve and from data of ice suspensions in salt
solutions. Mass flow in the liquid phase is described by Darcy's law. Thus,
salt flow as well as net water transfer can probably be predicted in unsaturated
frozen soil using information available from unfrozen systems.
72-73:020-088
HYDRAULIC CONDUCTIVITY EVALUATION OF THE SOIL PROFILE FROM SOIL WATER RETENTION
RELATIONS,
Bruce, R. R.
Agricultural Research Service, Watkinsville, Georgia, Soil and Water Conserva-
tion Research Division.
Soil Science Society of America Proceedings, Vol. 36, No. 4, p 555-561, July-
August 1972. 10 fig, 3 tab, 14 ref.
Descriptors: *Hydraulic conductivity, *Soil water movement, *Unsaturated flow,
*Moisture content, *Moisture tension, Particle size, Permeability, Percolation,
Soil physics. Soil types. Retention.
The water content-suction relation applicable to field soil horizons that differ
widely in texture was evaluated. Except for coarse-textured, organic; matter-
deficient horizons, soil water retention of sieved samples is significantly
94
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modified and does not represent the natural soil volume. Water content-
suction data from measurements on carefully procured core samples of each
horizon of a Typic Hapludult adequately represent their water retention charac-
teristics. Using appropriate water content-suction data, the hydraulic conduc-
tivity, water content relation calculated by published procedures was compared
with hydraulic conductivity measured on similar samples by a transient outflow
procedure. The calculated hydraulic conductivity-water content relations for
coarse grained systems or systems having a relatively narrow range of pore
size and well-defined bubbling pressure was sufficiently accurate for many
porposes. However, to obtain a useful evaluation of the unsaturated hydraulic
conductivity of fine-textured horizons with a very wide range of pore size and
poorly defined bubbling pressure, the Marshall or Millington and Quirk methods
had to be matched at a water content in the 0.1- to 0.3-bar range. Indiscrimi-
nate use of such methods of calculating hydraulic conductivity is inadvisable.
72-73:020-089
SALT DISPERSION COEFFICIENTS NEAR AN EVAPORATING SURFACE,
Todd, R. M., and Kemper, W. D.
Colorado State University, Fort Collins, Department of Agronomy.
Soil Science Society of America Proceedings, Vol. 36, No. 4, p 539-543, July-
August 1972. 7 fig, 3 tab, 7 ref.
Descriptors: *Dispersion, *Evaporation, *Soil water movement, Ion transport,
Diffusion, Mass transfer, Water chemistry. Convection, Salts, Diffusivity,
Aqueous solutions.
A series of laboratory experiments was conducted to gain detailed information on
water and salt movements near an evaporating surface. Columns instrumented
with tensiometers and salinity sensors were used with coarse- and fine-textured
soils. Water was supplied to a water table at the base of the columns and
approximately steady state evaporation from the soil surface was established.
Dispersion coefficients were calculated from salt gradients and evaporation
rates in regions of the soil where suctions ranged from 0.1 to several bars.
Dispersion increased solution flux and average solution velocity. Values
obtained for dispersion coefficients corresponded closely with those obtained
under more nearly saturated conditions at similar rates of solution flux.
72-73:020-090
A NOTE ON A THREE-PARAMETER SOIL-WATER DIFFUSIVITY FUNCTION-APPLICATION TO THE
HORIZONTAL INFILTRATION OF WATER,
Parlange, J. Y.
Yale University, New Haven, Connecticut, Department of Engineering and Applied
Science.
Soil Science Society of America Proceedings, Vol. 37, No. 2, p 318-319, March-
April 1973. 2 tab, 5 ref.
Descriptors: *Infiltration, *Diffusivity, *Diffusion, *Soil water movemerfc
Soil moisture. Mathematical studies. Equations.
Identifiers: ^Horizontal infiltration.
A realistic water-diffusivity function depending on three parameters described
recently by Ahuja and Swartzendruber is solved analitically for the horizontal
infiltration of water. The result is expressed in terms of elementary functions
and agrees very well with experimental observations.
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72-73:020-091
SOIL WATER PLOWMETERS WITH THERMOCOUPLE OUTPUTS,
Gary, J. W.
Agricultural Research Service, Kiniberly, Idaho, Snake River Conservation
Research Center.
Soil Science Society of America Proceedings, Vol. 37, No. 2, p 176-181, March-
April 1973. 7 fig, 1 tab, 8 ref.
Descriptors: *Flowmeters, *Soil water movement, *Water temperature, *Instru-
mentation, Thermometers, Temperature, Soil temperature. Heat flow, Seepage.
Identifiers: ^Thermocouples.
Two soil water flowmeters with thermocouple sensors are described. The meter
with a sensitivity of 0.1 mm of waterflow per day is recommended for flux
measurements in the surface meter of soil when the water matrix potential is
greater than 0.8 bar. Calibration factors for three soils with different
textures are presented as a family of curves. These curves may be interpolated
for using the flowmeter in other soils, possibly without a loss of accuracy
greater than the natural water flow variation from place to place in the field.
The meter with a sensivity of about 0.5 mm per day will require some additional
development and testing before it can be recommended for routine use. It
does offer the possibility of making measurements at soil water matric poten-
tials less than 1 bar and at relatively deep soil depths. The thermocouple
flow transducer developed for the meters may be used to measure saturated
soil waterflow or other liquid flows as small as 1 ml/day.
72-73:020-092
DYNAMIC MEASUREMENT OF SOIL AND LEAF WATER POTENTIAL WITH A DOUBLE LOOP
PELTIER TYPE THERMOCOUPLE PSYCHROMETER,
Chow, T.L., and De Vries, J.
British Columbia University, Vancouver, Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 37, No. 2, p 181-188, March-
April 1973. 11 fig, 14 ref.
Descriptors: *Soil moisture meters, *Water temperature, *Thermometers, Soil
temperature, Soil water movement, Calibrations, Temperature, Heat flow, Ground-
water potential, Soil-water-plant relationships, Potential flow.
Identifiers: *Psychrometers, *Thermocouples.
Details on the construction, calibration, and performatnce of a three-terminal
double loop thermocouple psychrometer are given. The thermal stability of this
psychrometer is about 40 times better than that of the two-terminal psychrometer
(Spanner type) for ambient temperature fluctuations with a time rate of change
greater than 0.2C/min. The response behaviors of a fritted glass bulb and a
ceramic bulb psychrometer were tested for vapor and for liquid phase water
movement. For vapor phase flow the fritted glass bulb exhibited a shorter
response time than the ceramic bulb psychrometer, whereas the reverse was true
when water movement was predominantly in the liquid phase. Water potential
measurements carried out on silty clay and silt loam soil samples were within
plus or minus 0.4 bar of those from the porous plate extractor. A system that
facilitates automatic and continuous in situ measurement of soil water potential
using the three-terminal psychrometer is described.
72-73:020-093
HORIZONTAL INFILTRATION OF WATER IN SOILS: A THEORETICAL INTERPRETATION OF
96
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RECENT EXPERIMENTS,
Parlange, J. Y.
Yale University, New Haven, Connecticut, Department of Engineering and Applied
Science.
Soil Science Society of America Proceedings, Vol. 37, No, 2, p 329-330, March-
April 1973. 1 fig, 5 ref.
Descriptors: *Infiltration, *Diffusivity, *Diffusion, *Soil water movement,
Soil moisture. Mathematical studies, Equations.
Identifiers: *Horizontal infiltration.
A general theory of water movement is used to describe the horizontal infil-
tration of water when the diffusivity increases exponentially with moisture
content. The results can be expressed in simple analytical form and are in
excellent agreement with experimental observations. The results confirm that
the theory is accurate because water diffusivity varies with water content.
72-73:026-094
WATER MOVEMENT AND CALICHE FORMATION IN LAYERED ARID AND SEMIARID SOILS,
Stuart, D. M., and Dixon, R. M.
Nevada University, Reno.
Soil Science Society of America Proceedings, Vol. 37, No. 2, p 323-324, March-
April 1973.
Descriptors: *Caliche, *Leaching, *Soil formation, Weathering, Calcareous soils,
Calcium carbonate, Hardpan, Infiltration, Soil water movement.
In soils, downward water movement is restricted when fine-textured materials
are underlain by sand or gravel layers. Water accumulates in arid and semiarid
soils at the interface of the fine- and coarse-textured materials and may
rarely enter the coarse-textured materials. Calcium carbonate, silica, and
other salts are deposited at or near the top of the sand or gravel layers as
water is removed by evapotranspiration. With time, silica, calcium carbonates,
and other salts become cemented or indurated, forming calcareous crusts at
these interfaces. The sands and gravels are not wet uniformly when water does
enter, because it enters relatively small areas. Calcareous concentrations
may form in these small, wetted areas and may be seen as calcareous cemented
columns surrounded by noncalcerous sands or gravels.
72-73:020-095
ANALYSIS OF MULTIDIMENSIONAL LEACHING,
Peck A. J.
Commonwealth Scientific and Industrial Research Organiztion, Wembley (Austra-
lia) , Division of Soils.
Soil Science Society of America Proceedings, Vol. 37, No. 2, p 320, March-
April 1973. 4 ref.
Descriptors: *Leaching, *Infiltration, *Steady flow. Soil water movement,
Drainage, Saline water, Equations, Saline soils.
A simplified analysis is given for leaching from the soil surface to tile
drains while infiltration is steady and uniform. Leachate concentration is
predicted to decay exponentially with characteristics determined by physical
parameters of the system. Predicted decay characteristics are in good agree-
ment with Mulqueen and Kirkham's experimental data.
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72-73:026-096
EFFECT OF TEMPERATURE ON PRESSURE HEAD-WATER CONTENT RELATIONSHIP
TIVITY OF TWO SOILS,
Haridasan, M.
Mississippi State University, State College, Department of Agronomy.
PhD Thesis, Mississippi State University Department of Agronomy, August 1971.
66 p, 19 fig, 3 tab, 48 ref.
Descriptors: *Soil water movement, *Soil moisture, *Pressure head, *Tempera-
ture, *Hydraulic conductivity. Laboratory tests. Analytical techniques. Soils,
Silts, Loam, Saturated soils, Unsaturated flow, Steady flow.
Identifiers: Steady state. Pressure plate outflow.
A series of experiments was conducted in the laboratory to study the effect of
temperature on the pressure head-water content relationship and the hydraulic
conductivity as a function of water content and pressure head in two soils.
Hydraulic conductivity of two silt loams were determined as a function of water
content and pressure head at constant temperatures of 15, 25, and 35 deg C by
steady state and pressure plate outflow methods. The pressure head at a given
water content increased as the temperature increased. The maximum changes
were observed in the region of inflection of the desorption curves. The water
content at a given pressure head decreased with a rise in temperature. Con-
ductivity of the soils at saturation increased as the temperature increased
and conductivity of unsaturated soils at a given water content increased with
a rise in temperature. The pressure plate outflow method seemed to be more
suitable for laboratory determination of hydraulic conductivity of unsaturated
soils than the steady-state method. Data obtained by the pressure plate out-
flow method were more consistent and required considerably less time to obtain
conductivity as a function of soil water content.
72-73:020-097
FIELD MEASUREMENT OF UNSATURATED HYDRAULIC CONDUCTIVITY BY INFILTRATION THROUGH
GYPSUM CRUSTS,
Bouma, J., and Denning, J. L.
Wisconsin Geological and Natural History Survey, Madison.
Soil Science Society of America Proceedings, Vol. 36, No. 5, p 846-847, Septem-
ber-October 1972. 2 fig, 3 ref.
Descriptors: ^Infiltration, *0n-site tests, *Unsaturated flow, *Hydraulic
conductivity, Soil water movement, Gypsum, Steady flow.
Identifiers: *Soil crusts.
Field trials were made to test the use of gypsum crusts in the crust test
method for measuring unsaturated hydraulic conductivity (K) in situ. Crust
consisting of mixtures of sand and gypsum were more stable and had more constant
hydraulic properties than previously used crusts consisting of various puddled
soil materials. Test results of four soil horizons are reported.
72-73:020-098
TRANSFORMATION OF MANGANESE IN A WATERLOGGED SOIL AS AFFECTED BY REDOX POTENTIAL
AND PH,
Gotoh, S., and Patrick, W. H., Jr.
Louisiana State University, Baton Rouge, Department of Agronomy.
Soil Science Society of America Proceedings, Vol. 36, No. 5, p 738-742, Septem-
ber-October 1972. 4 fig, 24 ref.
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Descriptors: *Manganese, *Soil chemistry, *Anaerobic conditions, *Oxidation-
reduction potential, *Solubility, *Hydrogen ion concentration, Oxidation,
Reduction (Chemical), Trace elements, Nutrients, Ion exchange.
Identifiers: *Soil manganese.
The distribution of different forms of manganese in waterlogged soil was stud-
ied over a wide range of closely controlled Eh-pH conditions. At pH 5 almost
all of soil manganese was converted from the reducible to the water-soluble
plus exchangeable fraction even at a redox potential as high as +500 mV. In
sharp contrast, at pH levels between 6 and 8 most of the conversion took place
at relatively lower redox potentials of +200 to +300 mV. When the water-
soluble plus exchangeable fraction was further divided into its two components,
low pH and low Eh increased water-soluble manganese at the expense of the
exchangeable form. Cation exchange reactions were important in regulating
the equilibria between water soluble and exchangeable manganese. Labeled
manganese added to the soil showed an almost identical distribution among the
various manganese fractions to that of native soil manganese. The observed
pMn/pH slope and Eo were much lower at pH 6 to 8 than those calculated for
pure equilibrium systems. The Eh and pH of flooded soils provide general
control of manganese transformation, which probably includes both chemical
and biological processes.
72-73:026-099
THE TRANSPORT OF CATIONS IN SOIL COLUMNS AT DIFFERENT PORE VELOCITIES,
Lai, S. H., and Jurinak, J. J.
Utah State University, Logan, Department of Soil Science and Biometeorology.
Soil Science Society of America Proceedings, Vol. 36, No. 5, p 730-733, Septem-
ber-October 1972. 5 fig, 2 tab, 14 ref.
Descriptors: *Ion transport, *Pore water, *Soil water movement, *Ion exchange,
Cation exchange, Adsorption, Leaching, Translocation, Clays.
Identifiers: *Cation transport (Soils).
The transport of Na and Mg in Ca-saturated Yolo loam soil column under saturated
steady state flow of different pore velocities was studied. The cation solution
was maintained at a concentration such that a linear adsorption isotherm describ-
ed the cation adsorption. Experimental retention curves were compared to the
theoretical solutions obtained from a linear equilibrium model. At low
relative concentrations, the equilibrium.adsorption of Na was significantly
less than that of Mg. At high pore velocities, the agreement of the experi-
mental retention curves with that of the theoretical calculation was good. At
low pore velocity, the agreement was poor. The retention volumes of Na and Mg
were smaller than those theoretically calculated and those obtained experi-
mentally at high pore velocity. Extensive tailing of Mg observed in the
experimental data was not described by the theoretical model.
72-73:02G-100
THE EFFECT OF BULK DENSITY AND INITIAL WATER CONTENT ON INFILTRATION IN CLAY
SOIL SAMPLES,
Gumbs, F. A., and Warkentin, B. P.
Macdonald College, Montreal (Quebec), Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 36, No. 5, p 720-724, Septem-
ber-October, 1972. 6 fig, 2 tab, 16 ref.
Descriptors: *Infiltration, *Expansive clays, *Expansive soil, *Bulk density,
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jiffusivity. Moisture content, Clays, Absorption, Adsorption, Soil water move-
ment.
Infiltration measurements were made on swelling clay soil samples packed into
columns. Small increases in bulk density over the range 1.10 to 1.25 g/cc
markedly decreased the rate of water movement. The magnitude of the effect
was greater for confined samples than unconfined samples at all initial water
contents. A 1-cm compact layer in the profile retarded water movement if the
soil was confined. In partially confined samples the soil in the compact
layer would swell on wetting, and water movement was retarded only when the
bulk density after swelling still exceeded the bulk density of the remainder
of the column. Bulk densities below 1.05 g/cc, and heat of wetting in partially
confined samples with 0% initial water content produced nonlinear relation-
ships of distance to wet front vs. square root of time. Under these experi-
mental conditions gravity contributed significantly to water movement at high
initial water content.
72-73:026-101
NITROGEN, SALINITY, AND ACIDITY DISTRIBUTION IN AN IRRIGATED ORCHARD SOIL AS
AFFECTED BY PLACEMENT OF NITROGEN FERTILIZERS,
Felizardo, B. C., Benson, N. R., and Cheng, H. H.
Philippines University, College, Laguna, Philippines.
Soil Science Society of America Proceedings, Vol. 36, No. 5, p 803-808, Septem-
ber-October, 1972." 6 fig, 2 tab, 13 ref.
Descriptors: *Nutrient removal, *Leaching, *Fertilizers, Nitrogen, Salinity,
Acidity, Fertilization, Application methods, Drainage effects, Environmental
effects.
A field experiment was conducted to determine the vertical and lateral changes
in the distribution of nitrogen, salinity, and acidity occurring in an irrigated
orchard soil following addition of (NH4) 2S04, NH4N03, or Ca(N03)2 by broadcast,
in broad band, or in narrow band. The NH4 and N03 contents in soil decreased
rapidly even under narrow band placements. Considerable nitrate movement was
observed. After 1 year, neither the total nor the inorganic N level in the
fertilized plots was significantly different from that of the control. High
salinity was detected under the narrow band placements, but the level diminished
rapidly with time. Little salinity was evident under the broad band or broad-
cast placements. However, the acidity produced by the ammonium fertilizers
persisted after 1 year. Changes in soil properties under narrow bands were
drastic, whereas changes under broad bands were insignificant.
72-73:026-102
MEASUREMENT OF THE DIFFUSION COEFFICIENT OF BORON IN SOIL USING A SINGLE CELL
TECHNIQUE,
Sulaiman, W. and Kay, B. D.
College of Agriculture, Malaya, Sungai Basi, Selangor, Malaysia.
Soil Science Society of America Proceedings, Vol. 36, No. 5, p 746-752, Septem-
ber-October, 1972. 5 fig, 3 tab, 20 ref.
Descriptors: *Nutrient removal, *Boron, *Trace elements, Nutrients, Diffusion,
Soil chemistry. Soil physics, Soil water.
The porous system diffusion coefficient. Dp, or boron in a loam soil was
measured by means of a single cell technique. Boron diffused from a semi-
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infinite medium of uniform initial concentration to a sink of constant concen-
tration which was separated from the soil by a dialysis membrane. A polyethy-
lene glycol 6,000 solution circulated through the sink and controlled the soil
matric suction osmotically. The diffusive flux at the soil and membrane inter-
face was treated as an evaporative process. The value of Dp was found to be
2.44 i 0.00000017 sq. cm/sec, when the bulk density of the soil and the
volumetric moisture content were 1.30 gm/cm3 and 0.31, respectively. The
significance of the equilibria between absorbed and solution B on the diffusion
rate of B was also studied. Addition to the soil of boric acid solutions of
concentrations lower than 1 ppm resulted in a capacity factor and solution B
concentration which were lower than the corresponding values when water con-
taining no B was added. As a consequence, the quantity of B diffusing into
the sink from the boron-treated soil was less than that from the untreated soil.
72-73:020-103
MANGANESE AND IRON SOLUBILITY CHANGES AS A FACTOR IN TILE DRAIN CLOGGING:
II. OBSERVATIONS DURING THE GROWTH OF COTTON,
Grass, L. B., MacKenzie, A. J., Meek, B. D., and Spencer, W. F.
Imperial Valley Conservation Research Center, Brawley, California.
Soil Science Society of America Proceedings, Vol. 37, No. 1, p 17-21, January-
February, 1973. 8 fig, 2 tab, 8 ref.
Descriptors: *Salinity, *Leaching, Manganese, Iron, Drainage, Subsurface
drainage, Tile drainage. Nitrates, Anaerobic conditions, Aerobic conditions.
Various levels of oxidation-reduction develop in the soil profile during the
irrigation and growing season of the cotton crop. Reducing intensity increased
with depth during the growing season and reached maximum intensity at the 6.10-
m depth. Reducing conditions favorable to increased solubility of Fe and Mn
were observed in the surface horizons of the profile during most of the season.
Changes in the solubility of manganese and iron occurred with changes in the
oxidation-reduction status in the soil profile. Manganese began to dissolve
at 400 mV and became significant at less than 300 mV. Increased concentration
of nitrate retarded reduction of oxidized Fe and Mn compounds. The salinity
of the soil solution affected the concentration of soluble manganese and iron.
The presence of N03-N in the soil solution in amounts less than 0.2 ppm
retarded the dissolution of Mn compounds. The solubility of manganese and
iron can probably be controlled by controlling or regulating the oxidation-
reduction status of the soil profile by reducing the waterlogging period
after irrigation to a minimum.
72-73:020-104
COINCIDENCE AND INTERFERENCE CORRECTIONS FOR DUAL-ENERGY GAMMA RAY MEASUREMENTS
OF SOIL DENSITY AND WATER CONTENT,
Mansell, R. S., Hammond, L. C., and McCurdy, R. M.
Florida University, Gainesville, Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 500-504, July-
August 1973. 3 fig, 2 tab, 11 ref.
Descriptors: *Nuclear moisture meters, *Soil moisture meters, *Gamma rays,
Bulk density, Soil water, Calibrations, Instrumentation.
Identifiers: Gamma-ray spectrometers.
Volumetric water content and bulk density changes in a soil column can be
simultaneously and rapidly determined from single-detector attenuation measure-
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ments of a high intensity, dual-energy beam of gamma photons. Coincidence loss
due to interference between the two monoenergetic gamma rays and Compton
scattering provides gamma photon intensities which are undesirably interdepend-
ent. Correction procedures are given for providing independent determinations
of both 60 and 662 keV gamma ray intensities.
72-73:020-105
MANGANESE AND IRON SOLUBILITY CHANGES AS A FACTOR IN TILE DRAIN CLOGGING: I.
OBSERVATIONS DURING FLOODING AND DRYING,
Grass, L. B., MacKenzie, A. J., Meek, B. D., and Spencer, W. F.
Imperial Valley Conservation Research Center, Brawley, California.
Soil Science Society of America Proceedings, Vol. 37, No. 1, p 14-17, January-
February, 1973. 5 fig, 1 tab, 27 ref.
Descriptors: *Salinity, *Leaching, Manganese, Iron, Drainage, Subsurface
drainage, Tile drainage, Nitrates, Anaerobic conditions. Aerobic conditions.
A field study of waterlogging and subsequent drying of the soil profile has
shown that under irrigation culture in Imperial Valley reducing conditions be-
came prevalent. Reducing conditions, as indicated by declining Eh values,
became most favorable for dissolution of Mn and Fe near the soil surface.
However, the concentrations of Mn2 and Fe2 were lowest near the surface, prob-
ably because of their leaching from this zone, and the shorter time of contact
between soil solution and soil particles. The concentration of Fe2 and Mn2
were higher in the deeper horizons of the soil profile. In the plow layer,
the reducing intensity increased, beginning 9 m away from the tile and reach-
ing a maximum 18- to 23-cm from the tile drain. The Eh levels in the soil
profile declined immediately after irrigation began and rose immediately
after irrigation stopped indicating the importance of atmospheric oxygen to the
oxidation-reduction status and, therefore, to the solubility of iron and
manganese compounds. Soluble organic carbon apparently was not related to the
concentration of Mn2 and in the soil solution even though the decomposition of
soil organic matter is important in oxidation-reduction reactions in the soil
profile.
72-73:020-106
NITRATE CONCENTRATIONS IN THE UNSATURATED ZONE BENEATH IRRIGATED FIELDS IN
SOUTHERN CALIFORNIA,
Pratt, P. F., and Adriano, D. C.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Soil Science Society of America Proceedings, Vol. 37, No. 2, p 321-322, March-
April, 1973. 1 fig, 1 tab, 5 ref.
Descriptors: *Drainage, *Nutrient removal, Nitrogen, Leaching, Denitrification,
Nitrates, Crop response. Crop production.
Nitrate concentrations in the drainage water of the unsaturated zone beneath
the soil-root zone were predicted from data for N inputs, N removal in har-
vested crops, and the drainage volume. Ratios of these predicted values to
measured values were related to the volatilization losses or unaccounted-for in-
puts expressed as a fraction of the excess N defined as the N input minus N
removal in harvested crops. Volatilization losses or unaccounted-for inputs
were calculated as known inputs minus removal in harvested crops minus that
removed from the soil-root system by leaching.
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72-73:020-107
EFFECTS OF STRAW, CALCIUM CHLORIDE, AND SUBMERGENCE ON A SODIC SOIL,
Puttaswamygowda, B. S., and Pratt, P. F.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Soil Science Society of America Proceedings, Vol. 37, No. 2, p 208-212, March-
April, 1973. 5 fig, 3 tab, 15 ref.
Descriptors: *Saline soils, *Alkali Soils, Salinity, Leaching, Reduction
(chemical), Soil chemistry, Soil physics, Organic matter, Anaerobic conditions,
Aerobic conditions.
The effects of straw and CaCl2 during 130 days of submergence, and the effects
of these amendments under submerged aerobic vs. anaerobic conditions for a
period of 30 days were studied. Comparisons of pH, EC, Na, Ca + Mg, K, Fe,
the optical density of the water extract, and ESP were used to evaluate the
effects of these amendments. The straw and straw + CaCl2 treatments had the
largest effect in lowering the pH and the ESP, increasing the Na and Ca +
Mg concentrations and the EC. Submerged anaerobic conditions had the largest
effect on promoting these reactions. The concentrations of Fe2 was highest
in the straw treatments whereas CaCl2 had a depressing effect on the soluble
Fe2. The optical density was lowest in the straw plus CaCl2 amendment treated
soil and the effect of this treatment was larger under anaerobic conditions.
Wheat straw under anaerobic conditions caused an increase in the sum of Na
plus Ca plus Mg that was about three times greater than the sum of these
cations in the straw itself. In combination with CaC12 wheat straw reduced
the loss of Ca from solution observed when CaC12 alone was added to soil.
72-73:020-108
AN OSCILLATOR CIRCUIT FOR AUTOMATED SALINITY SENSOR MEASUREMENTS,
Austin, R. S., and Oster, J. D.
United States Salinity Laboratory, Riverside, California.
Soil Science Society of America Proceedings, Vol. 37, No. 2, p 327-329, March-
April, 1973. 3 fig, 1 tab, 10 ref.
Descriptors: *Salinity, Electric conductance, Specific conductivity, Soil
chemistry, Water chemistry, Saline soils.
An oscillator circuit is described that enables automatic reading of
salinity sensors and other a.c. conductivity cells by measuring frequency of
oscillation. The oscillator frequency varies between 0.13 to 30 KHz and changes
linearly with conductance in the range of 0.03 to 10 mmho/cm. The temperature
sensitivity of the frequency of the oscillator is negligible between 8 and 31
C. The calibration curves between frequency and conductance obtained with
the oscillator circuit for both the electrical conductivity and thermistor
elements of the salinity sensor are linear and readings can be obtained with
lead lengths of several hundred meters.
72-73:020-109
FLOOD AND SEEPAGE WATER SAMPLING TECHNIQUES, IN RICE FIELDS UNDER DIFFERENT
WATER MANAGEMENT PRACTICES,
Tanji, K. K., Biggar, J. W., Mehran, M., and Henderson, D. W.
California University, Department of Water Science and Engineering, Davis.
Soil Science Society of America Proceedings, Vol. 37, No. 3, p 483-485, May-
June, 1973. 3 fig, 1 tab.
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Descriptors: *Water pollution sources, *Nutrient removal, Leaching, Water
sampling, Rice, Flooding, Seepage.
Sampling equipment reported herein enables collection of flood and seepage
waters to determine persistence and transport of chemicals applied in flooded
rice culture. This system gives a capability of cultivating the effects of
different chemical application methods (Water-applied, soil-incorporated) and
water management systems (static, flow-through, and recycled).
72-73:020-110
MODEL FOR ESTIMATING SOIL WATER, PLANT, AND ATMOSPHERIC INTERRELATIONS: I.
DESCRIPTION AND SENSITIVITY,
Nimah, M. N., and Hanks, R. J.
Utah State University, Utah Water Research Laboratory, Logan.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 522-527,
July-August, 1973. 11 fig, 3 tab, 16 ref.
Descriptors: ^Drainage, *Soil-water-plant relationships, *Soil water, Evapo-
transpiration, Computer models, Root systems. Soil water movement.
A model and its numerical solution were developed to predict water content
profiles, evapotranspiration, water flow from or to the water table, root
extraction, and root water potential under transient field conditions. Soil
properties needed are hydraulic conductivity and soil water potential as
functions of water content. Plant properties needed are rooting depth and
limiting root water potential. Climatic properties needed are potential evapo-
ration and potential transpiration. The model predicted significant changes in
root extraction, evapotranspiration, and drainage due to the variations in
pressure head-water content relations and root depth. Variations in the
limiting root water potential had a small influence on estimated evapotrans-
piration, drainage, and root extraction.
72-73:020-111
MODEL FOR ESTIMATING SOIL WATER, PLANT, AND ATMOSPHERIC INTERRELATIONS: II.
FIELD TEST OF MODEL,
Nimah, M. N., and Hanks, R. J.
Utah State University, Utah Water Research Laboratory, Logan.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 528-532, July-
August, 1973. 11 fig, 1 tab, 7 ref.
Descriptors: *Drainage, *Soil-water-plant relationships, *Soil water, Evapo-
transpiration, Computer models, Root systems. Soil water movement.
A mathematical model was developed to predict water content profiles, evapo-
transpiration, wal-er flow from or to the water table, root extraction, and
root water potential at the surface under transient conditions. The model
was field tested in 1970 and 1971. With alfalfa as the crop, predicted and
computed water content-depth profiles show best agreement 48 hours after any
water addition. The poorest agreement for all crops tested was right after
irrigation. The computed cumulative upward water flow from the water table
was 4.80 cm as compared to 0.0 cm measured for the whole 1971 season of 116
days.
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72-73:020-112
EFFECTS OF DRAINAGE AND ORGANIC AMENDMENTS ON THE RECLAMATION OF A SODIC SOIL
CROPPED WITH RICE,
Puttaswamygowda, B. S., Wallihan, E. F., and Pratt, P. F.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 621-625, July-
August, 1973. 6 fig, 3 tab, 22 ref.
Descriptors: *Salinity, *Sodium, *Alkaline soils, Soil chemistry, Organic
matter, Drainage, Soil physics.
In a greenhouse pot culture study, effects of drainage and organic amendments
on the reclamation of a saline sodic soil material under submerged conditions
were studied with and without the presence of a rice crop. In drained soils,
application of dairy manure, sugar, straw or straw + CaCl2 increased the rate
of drainage and decreased the electric conductivity and exchangeable sodium
percentage. Without drainage, treatments were less effective. Crop growth
hastened the reclamation process by increasing the volume of water drained
and the concentration of Ca + Mg in the drainage water. Drainage had a signi-
ficant effect on the vegetative growth of rice, percentage of earbearing
tillers, and straw and grain yield. In the undrained condition, organic soil
amendments, except dairy manure, adversely affected the straw and grain yield.
72-73:020-113
CONTROLLED INSTANTANEOUS APPLICATION OF FREE WATER TO A POROUS SURFACE,
Swartzendruber, D., and Asseed, M. S.
Purdue University, West Lafayette, Indiana.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 967-968,
November-December, 1973. 1 fig.
(See 72-73:04A-034)
72-73:026-114
VACUUM EXTRACTORS TO ASSESS DEEP PERCOLATION LOSSES AND CHEMICAL CONSTITUENTS
OF SOIL WATER,
Duke, H. R., and Haise, H. R.
United States Department of Agriculture, Agricultural Research Service, Fort
Collins, Colorado.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 963-064,
November-December, 1973. 3 fig.
Descriptors: *Soil water, *Drainage effects. Infiltration, Percolation, Soil
water movement, Leaching, Water quality.
A vacuum extractor, consisting of a porous ceramic tube within a sheet-metal
trough, has been developed to provide a quantitative measure of soil water lost
by deep percolation and to provide a water sample for chemical analysis.
Several of these extractors have been installed in the field and preliminary
field performance is reported. Detailed laboratory evaluation is in progress.
72-73:020-115
A NEW APPROACH TO SOIL TESTING: II. IONIC EQUILIBRIA INVOLVING H, K, Ca, Mg,
Mn, Fe, Cu, Zn, Na, P, and S,
Baker, D. E.
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Pennsylvania Agricultural Experiment Station, University Park.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 537-541, July-
August, 1973. 6 tab, 24 ref.
Descriptors: *Soil chemistry, *Ions, *Soil tests, Salinity, Soil analysis.
Soil investigations. Soil properties. Soil science.
Several experiments were conducted in an effort to modify a new approach to
soil testing in which the equilibrating or testing solution contains each
element for which the soil is being tested. This report includes results for
modification which caused 15 soils to differ more with respect to test levels
of Mn, Fe, Zn, Cu, S, and P without substantially changing their rankings for
K, Ca, and Mg. Modifications included the incorporation of a preservative,
a flocculating agent, a pH buffer, DTPA, and several additional elements to
maintain a relatively constant activity coefficient for each element in differ-
ent soils. Results concluded that the adsorption equilibria soil test can be
used successfully to test for several elements. The approach for calculating
soil requirements is given for P. Although the test shows promise by indicat-
ing soil differences, additional calibration data will be required prior to
routine use of the method.
72-73:020-116
PRINCIPLES OF MANAGING HIGH FREQUENCY IRRIGATION,
Rawlins, S. L.
United States Salinity Laboratory, Riverside, California.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 626-629, July-
August, 1973. 3 fig, 6 ref.
Descriptors: *Irrigation practices, *Irrigation, Irrigation systems, Irrigation
design, Sprinkler irrigation, Soil physics, Soil science.
The consequences of increasing irrigation frequency are explored, taking into
consideration the laws governing water flow in soil. As frequency increases,
the waterholding capacity of the soil becomes less important because water is
supplied as the plants require it. Soil water content, and therefore matric
potential, are continuously high and only slightly dependent upon deep percola-
tion rate. This makes the need for deep percolation to leach salts the only
valid criterion for applying more water than the plants transpire. The need
to apply extra water to those crops that require high soil water content is
eliminated. Controlling the deep percolation rate rather than water potential
as inputs for managing the quantity of water to be applied.
72-73:020-117
RESPONSE OF SALINITY SENSORS TO RAPIDLY CHANGING SALINITY,
Wesseling, J., and Oster, J. D.
Agricultural Research Service, Riverside, California, Salinity Laboratory.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 553-557, July-
August 1973. 5 fig, 3 tab, 12 ref.
Descriptors: *Salinity, *Electrical conductance, ^Instrumentation, Calibra-
tions, Water chemistry. Diffusion, Diffusivity.
Identifiers: *Soil salinity meters.
A theory developed to describe the response of the sensor to changes in soil
salinity is based on the assumption that diffusion of solutes into and out of
106
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the sensitive element of a salinity sensor determines its response time.
This theory was experimentally verified in solution and in soils. The response
of a sensor is adequately described by a single response factor. Proper use
of this factor permits the actual electrical conductivity of the soil solution
to be inferred from sensor readings where soil salinity changes rapidly.
72-73:020-118
A STUDY OF THE UNIQUENESS OF THE SOIL MOISTURE CHARACTERISTIC DURING DESORPTION
BY VERTICAL DRAINAGE,
Vachaud, G., Vauolin, M. and Wakil, M.
Universite Scientifique et Medicalede Grenoble, Laboratoiries de Mecanique
des Fluides, Grenoble, France.
Soil Science Society of America Proceedings, Vol. 36, No. 3, p 531-532, May-
June, 1972. 2 fig, 6 ref.
Descriptors: *Soil water, *Drainage, Transition flow, Tensiometers, Soil
moisture.
Previous experiments concerning the desorption of a horizontal column of
uniform soil suggested that the moisture characteristic was not unique through-
out the column. Further desorption experiments have been carried out on a
vertical column. The results are consistent with those obtained previously,
and give further information on the dual dependence of Psi on Theta and on
partial derivative of Psi over the partial derivative of t.
72-73:02G-119
NITROGEN MINERALIZATION POTENTIALS OF SOILS,
Stanford, G., and Smith, S. J.
United States Soils Laboratory, Beltsville, Maryland.
Soil Science Society of America Proceedings, Vol. 36, No. 3, p 465-472, May-
June, 1972. 2 fig, 5 tab, 16 ref.
Descriptors: *Nutrient removal, *Nitrogen, Leaching, Nigrogen fixation, Incuba-
tion.
Net mineralization of N in 39 widely differing soils was determined over a 30-
week period at 35C, using incubation intervals of 2, 2, 4, 4, 4, 6, and 8
weeks. Mineral N was leached from the soils before the first incubation and
following each of seven incubations by means of 0.01M CaC12 and a minus-N
nutrient solution. Soil water contents were adjusted by applying suction,
and losses of water during incubation under aerobic conditions were negligible.
With most soils, cumulative net N mineralized was linearly related to the square
root of time. The pH of soils changed very little in the course of 30 weeks'
incubation. Because of the generally consistent results, the data were employed
in calculating the N mineralization potential, No, of each soil, based on the
hypothesis that rate of N mineralization was proportional to the quantity of
N comprising the mineralizable substrate. Values of No ranged from about 20
to over 300 ppm of air-dry soil. The fraction of total N comprising No varied
widely among soils. Mineralization rate constants did not differ significantly
among most of the soils.
72-73:020-120
COLORIMETRIC, SEMIQUANTITATIVE TEST FOR SOIL SALINITY,
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Bower, C. A.
United States Salinity Laboratory, Riverside, California.
Soil Science Society of America Proceedings, Vol. 36, No. 3, p 527-528, May-
June, 1972. 2 tab.
Descriptors: *Salinity, Measurement.
Identifiers: Field test
A colorimetric, semiquantitative test for soil salinity is described based on
the equivalent release of yellow Cr04 ion upon reaction of Cl and S04 with
slightly soluble Ag2Cr04 and SrCr04, respectively, to form less soluble AgCl
and SrS04.
72-73:026-121
FURTHER EVIDENCE FOR THE INABILITY OF THE KJELDAHL TOTAL NITROGEN METHOD TO '
FULLY MEASURE INDIGENOUS FIXED AMMONIUM NITROGEN IN SUBSOILS,
Meints, V. W., and Peterson, G. A.
Nebraska Agricultural Experiment Station, Lincoln.
Soil Science Society of America Proceedings, Vol. 36, No. 3, p 434-436, May-
June, 1972. 2 tab, 6 ref.
Descriptors: *Fertility, *Nutrients, Nitrogen, Soil chemical properties,
Subsoil, Nitrates.
Three methods of Kjeldahl total N determinations in soils were compared.
Method 1 involved a pretreatment of the soil with a HF-acid mixture and
resulted in higher N values than methods 2 or 3 which involved a long period
of digestion and a modification of a Gunning method, respectively. Differences
in total N values obtained by the three methods were greatest for subsoils.
The inability of methods 2 and 3 to measure all of the indigenous fixed NH4+-N
resulted in low N values and erroneously high C:N ratios in the subsoil.
72-73:026-122
INTERACTION EFFECTS OF BORON AND LIME ON BARLEY,
Gupta, U. C.
Canada Department of Agriculture, Research Station, Charlottetown, Prince
Edward, Island.
Soil Science Society of America Proceedings, Vol. 36, No. 2, p 332-334, Match-
April, 1972. 3 tab, 15 ref.
Descriptors: *Nutrient requirements, *Trace elements, *Bbron, Toxicity, Crop
response. Barley, Salts, Salinity.
A greenhouse study involving'six levels of B and four levels of lime was con-
ducted on barley. Boron toxicity symptoms occurred at 0.5 to 4.0 ppm applied
B, with the most severe symptoms occurring at 4.0 ppm B level at soil pH 5.3.
At 0.5 ppm B, no visible symptoms occurred at pH values of 6.3 and 6.8, and at
1.0 ppm B no symptoms occurred at pH 6.8. There was a highly significant
soil pH x B interactipn, in which high rates of B were more detrimental to
kernel yields at lower pH than at high pH values. The highest kernel yields
were recorded with 0.25 ppm B at soil pH 5.8. An application of 4.0 ppm B
at soil pH 5.3 and 5.8 did not produce any kernels. A range in the B concentra-
tion of 1.4 to 9.9 ppm and in Ca/B ratio of 343 to 1,159 in the b.s.t. collect-
ed from Prince Edward Island fields indicated a deficiency of B in many soils
for growing barley. However, no visible B deficiency symptoms were found
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either under greenhouse or field conditions.
72-73:020-123
CALCIUM-MAGNESIUM-POTASSIUM EQUILIBRIA IN SOME CALIFORNIA SOILS,
Carlson, R. M., and Buchanan, J. R.
California University, Department of Pomology, Davis.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 851-855,
November-December, 1973. 5 fig, 3 tab, 19 ref.
Descriptors: *Salinity, *Ion exchange, Ions, Leaching, Fertilizers, Potassium,
Nutrient removal, Equilibrium.
Ion exchange equilibria in several soils were studied to seek equilibrium
equations that could be used in chromatographic models dealing with movement
and distribution of fertilizer potassium in soil profiles. Soil samples were
equilibrated with mixtures of CaCl2, MgCl2, and KCl solutions and then extract-
ed with NH40Ac to determine exchangeable cation compositions at equilibrium.
It was necessary to correct the exchangeable cation concentrations by subtract-
ing the cations extracted from nonexchangeable sources by NH40Ac. Vanselow's,
Davis1, Capon's or Kerr's equation would not describe the equilibria. Equations
were developed to describe the equilibria.
72-73:020-124
THE SIMULTANEOUS EFFECT OF pH AND CHLORIDE CONCENTRATIONS UPON MERCURY (II) AS
A POLLUTANT,
Hahne, H. C. H. and Kroontje, W.
Virginia Polytechnic Institute and State University, Blacksburg.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 838-843,
November-December, 1973. 8 fig, 2 tab, 25 ref.
Descriptors: *Mercury, Pollutants, Salinity, Water quality, Water pollution
sources.
The mercuric ion, compared to other heavy metal pollutants, hydrolyzes at low
pH values and forms soluble chloride complexes at low chloride concentrations.
To evaluate the possible implications of such behavior in natural aquatic
systems, Hg(II) hydroxy and chloride species distributions were calculated
using pH and chloride ion concentrations as variables simultaneously. Range
in pH values selected was from 2 to 9 to cover conditions encountered in acid
mine drainages, rivers, all types of soil solution extracts, and sea-water.
In addition, a study was performed in which montmorillonite, illite, and
kaolinite were equilibrated with different HgCl2 solutions. The range of
HgCl2 concentrations in equilibrium solutions was 1.25 x 10-4M to 0.005M.
Results of the calculations show that chloride complexes compete effectively
with the hydroxy complexes of Hg(II).
72-73:020-125
THE EFFECT OF EXCLUSION VOLUME ON POTENTIOMETRIC NITRATE MEASUREMENTS,
Gilmour, J. T., and Scott, H. D.
Arkansas University, Agronomy Department, Fayetteville.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 959-960,
November-December, 1973. 1 fig, 2 tab, 10 ref.
Descriptors: Nitrates,Nitrogen, Clays,Montmorillonite.
109
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Data are presented which show that large anion exclusion volumes can occur when
tnontmorillonitic soils, low in total salt, are extracted with water. Nitrate
measurements on such extracts with the nitrate specific ion electrode reflect
this exclusion volume induced error. A possible solution to the problem is
suggested.
72-73:026-126
TEST OF A NEW MODEL FOR THE KINETICS OF ADSORPTION-DESORPTION PROCESSES,
Griffin, R. A., and Jurinak, J. J.
Utah State University, Logan.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 869-872,
November-December, 1973. 5 fig, 1 tab, 8 ref.
Descriptors: *Nutrient removal. Phosphates, Adsorption, Thermodynamics, Mathe-
matical models, Computer models.
A new model for the kinetics of adsorption-desorption processes proposed by
Lindstrom, Hague, and Coshow (1970) was tested with adsorption and desorption
data for the interaction of phosphate with the calcite mineral surface. The
model was found to offer considerable advantages in speed and convenience to
those users whose experimental conditions correspond to the assumptions inherent
in the derivation of the model. There was reasonable agreement between the
predicted adsorption kinetic parameters and experimental data. However, con-
siderable disparity was observed between predicted and experimental desorption
parameters. It was concluded that the model was not valid for endothermic
processes.
72-73:02G-127
SOLUTION AND ADSORBED FLUOMETURON CONCENTRATION DISTRIBUTION IN A WATER-
SATURATED SOIL: EXPERIMENTAL AND PREDICTED EVALUATION,
Hornsby, A. G., and Davidson, J. M.
United States Environmental Protection Agency, Ada, Oklahoma.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 823-828,
November-December, 1973. 7 fig, 2 tab, 12 ref.
Descriptors: Adsorption, Solutes, Soil water, Soil moisture, Salinity.
Identifiers: Desorption, Miscible displacement. Dispersion coefficient,
Solute transport model.
A technique is described for measuring the solution and adsorbed phases of
fluometuron in water-saturated soil columns. The data reveal that at an
average pore-water velocity of 5.5 cm/hour, the solution and adsorbed phases of
fluometuron are not in equilibrium, whereas, at the 0.59 cm/hour velocity they
were in equilibrium. The kinetic rate equations for adsorption and desorption
were not significantly better than the equilibrium model when describing the
fast displacement of fluometuron through soils. The desorption distribution
coefficient was found to be a function of the maximum amount of herbicide
adsorbed prior to desorption. The experimental data were reasonably well
described by the mathematical model.
72-73:020-128
UNSTEADY TWO-DIMENSIONAL FLOW OF WATER IN UNSATURATED SOILS ABOVE AN IMPER-
VIOUS BARRIER,
Selim, H. M., and Kirkham, D.
110
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Iowa State University, Ames, Department of Agronomy.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 489-495, July-
August 1973. 6 fig, 20 ref.
Descriptors: *Soil water movement, *Wetting, *Unsaturated flow, *Aquicludes,
Unsteady flow, Ditches, Numerical analysis, Drainage systems.
The equation describing unsteady two-dimensional water flow in unsaturated
soils may be solved by use of a finite difference approximation and an alter-
nating-direction implicity method. The two-dimensional medium is a homogeneous
soil with an impervious barrier at some depth from the soil surface and
having equally spaced trenches. The bottoms of the trenches are wetted at
time zero and are kept at a constant 0.50 water content. The initial soil
water content is 0.20. Water movement from the walls of the trenches and the
soil surface is neglected. The water content at all locations in the flow
medium was obtained for an Ida silt loam soil with two geometries. Near
trenches with 120-cm spacing, 30-cm deep, and 30-cm wide, the wetting front
reaches a depth of 30 cm in 35 min, and reaches the soil surface in 140 min.
Near trenches with 60-cm spacing, 15-cm deep, and 15-cm wide, the wetting front
reaches a depth of 30 cm in 45 min, and reaches the soil surface in 30 min.
72-73s02G-129
CULTURAL PRACTICES FOR IRRIGATED WINTER WHEAT PRODUCTION,
Unger, P. W., Allen, R. R., and Parker, J. J.
United States Department of Agriculture, Southwestern Great Plains Research
Center, Bushland, Texas.
Soil Science Society of America Proceedings, Vol. 37, No. 3, p 437-442, May-
June, 1973. 5 tab, 21 ref.
Descriptors: Cultivation, *Irrigation, Infiltration, Water use. Efficiencies,
Organic matter, Nitrogen, Bulk density, Wheat.
Rototilling, moldboard plowing, disking, burn-listing, and listing were satis-
factory tillage methods for managing the residues produced by continuous irri-
gated winter wheat. Grain yields averaged highest for moldboard plowing and
lowest for lister plowing. Nitrogen fertilizer at 90 or 135 kg N/ha resulted
in significant grain and residue yield differences in a few years, but no
consistent trends were apparent. Irrigation water infiltration was highest
for moldboard plowing and lowest for lister plowing. The list and burn-list
treatments resulted in similar infiltration. Water-use efficiencies were
similar for all treatments. At the end of the 5-year study, soil organic
matter content was lowest (1.66%) for burn-lister tillage and highest (1.72%)
for lister and disk tillage. Water-stable aggregation was highest (84.5%)
for rototilling and lowest (79.3%) for burn-lister tillage. Bulk density
increased in all plots, but it increased the least in plots that were mold-
board plowed.
72-73:02G-130
SALT TOLERANCE OF MEXICAN WHEAT: I. EFFECT OF NO3 AND NaCl ON MINERAL NUTRI-
TION, GROWTH, AND GRAIN PRODUCTION OF FOUR WHEATS,
Torres, B. C., and Bingham, F. T.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Soil Science Society of America Proceedings, Vol. 37, No. 5, p 711-715, Septem-
ber-October, 1973. 5 fig, 8 tab, 15 ref.
Ill
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Descriptors: *Fertility, *Crop response, *Salinity, Nutrients, Nitrogen, Crop
production, Soil chemical properties, Crops.
Wheat plants were grown to full maturity under sand culture conditions with
variable levels of substrate N03 and NaCl. Leaf samples were collected at
early spike emergence for chemical analysis of Ca, Mg, Na, K. P. Cl, NO3, and
total N. Growth measurements included those of flag leaf length, tiller and
spike formation, and total straw and grain. The slower maturing variety,
Cajeme 71, grew much more vigorously than the more rapidly maturing varieties
Inia 66, Yecora, and Siete Cerros. The salt tolerance of Cajeme 71 was 2- to
4-fold greater than that of the other varieties tested. Leaf NO3 of samples
collected at early spike emergence correlated with grain yields irrespective of
substrate NaCl levels, suggesting that the growth retardation associated with
excessive substrate NaCl was due in part to a Cl-induced NO3 deficiency.
72-73:020-131
A MATHEMATICAL INVESTIGATION OF STEADY INFILTRATION FROM LINE SOURCES,
Zachmann, D. W., and Thomas, A. W.
Colorado State University, Fort Collins, Department of Mathematics.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 495-500, July-
August 1973. 4 fig, 8 ref.
Descriptors: *Infiltration, *Soil water movement, *Subsurface irrigation,
Evaporation, Equations, Hydraulic conductivity.
Equations which can be used in the design of subsurface irrigation systems are
based on the physics of steady infiltration from a distribution of line sources
which lie in a horizontal plane and are parallel and equally spaced. The
analytical solution describes the flow from the line sources in the presence
of uniform infiltration or evaporation at the soil surface. To increase the
utility of the solution, the equations for matric flux potential and stream
function are written in dimensionless form.
72-73:020-132
RECOVERY OF N15-LABELED FERTILIZERS IN FIELD EXPERIMENTS,
Westerman, R. L., Kurtz, L. T., and Hauck, R. D.
Illinois University, Urbana.
Soil Science Society of America Proceedings, Vol. 36, No. 1, p 82-86, January-
February, 1972. 2 fig, 3 tab, 14 ref.
(See 72-73:058-072)
72-73:020-133
APPLIED AND RESIDUAL NITRATE-NITROGEN EFFECTS ON IRRIGATED GRAIN SORGHUM YIELD,
Onken, A. B., and Sunderman, H. D.
Texas A & M University, Agricultural Research and Extension Center, Lubbock.
Soil Science Society of America Proceedings, Vol. 36, No. 1, p 94-97, January-
February, 1972. 4 tab, 14 ref.
Descriptors: *Nutrient removal, *Nitrogen, *Crop response. Crop production.
Crops, Leaching, Water pollution sources.
Multirate nitrogen studies were conducted for a 3-year period, on an irrigated
clay loam soil at two locations, to determine the influence of applied and
112
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residual soil N on the yield of grain sorghum. Soil samples were taken prior
to fertilizer application in depth increments of 0-15, 15-30, 30-61, and 61-91
cm and analyzed for nitrate. Applied and residual soil NO3-N were found to
influence grain yields. Regression analysis of the data showed highly signifi-
cant relationships between quantities of soil nitrates measured at upper
depths to those measured at lower depths, and grain yield and applied N +
residual NO3-N. Best correlations were obtained when residual NO3-N was includ-
ed in the regression equation. Results indicated that soil samples taken to 15
or 30 cm would be sufficient for evaluation of residual nitrogen effects.
72-73:02G-134
PREDICTING OPTIMUM DEPTH OF PROFILE MODIFICATION BY DEEP PLOWING FOR IMPROVING
SALINE-SODIC SOILS,
Rasmussen, W. W., and McNeal, B. L.
United States Department of Agriculture, Agricultural Research Service, Snake
River Conservation Research Center, Kimberly, Idaho.
Soil Science Society of America Proceedings, Vol. 37, No. 3, p 432-437, May-
June, 1973. 2 fig, 3 tab, 14 ref.
Descriptors: *Saline soils, *Deep tillage, *Hydraulic conductivity, Permeabil-
ity, Soil management, Infiltration.
Identifiers: Deep plowing.
A previously developed procedure for predicting the effect of mixed-salt solu-
tions on soil hydraulic conductivity (HC) was used to predict the relative
hydraulic conductivity (RHC) of separate soil horizons from saline-sodic soils,
using a standard low-salt solution following a standard high-salt solution at
a fixed exchangeable-sodium level. These values were then used to predict the
RHC of mixtures of the same horizons simulating profiles modified to various
depths by deep plowing. Weighting RHC values for individual horizons by the
depth fraction of each horizon in the soil mixture provided RHC values of proper
magnitude, except when large proportions of calcareous subsolum material were
incorporated into the mixture. Results were improved by multiplying calculated
RHC values for each soil mixture by the initial HC of the mixture. Results
were consistent with lysimeter and field plot observations on the same soils,
including deep plowing trials.
72-73:020-135
PRIMING EFFECT OF N-15 LABELED FERTILIZERS ON SOIL NITROGEN IN FIELD EXPERIMENTS,
Westerman, R. L., and Kurtz, L. T.
Arizona University, Department of Soils, Tucson.
Soil Science Society of America Proceedings, Vol. 37, No. 5, p 725-727, Septem-
ber-October, 1973. 1 tab, 15 ref.
Descriptors: *Nutrient removal, *Nitrogen, Leaching, Crop response, Water
pollution sources. Fertilizers, Stable isotopes, Isotope studies.
Evidence of the "priming effect" on the uptake of soil N by additions of
conservative amounts of fertilizer N was examined in data from two recently
reported field experiments. In these experiments, urea and oxamide each
labeled with N15 were compared on adjacent locations in successive years with
'Sudax SX111 Sorghum-sudan hybrid as the test crop. Additions of N fertilizer
increased the uptake of soil N by 17 to 45% in the first experiment and by 8
to 27% in the second experiment. In the residual cutting of the first experi-
ment, increases in uptake of soil N by the crops was speculated to be due to
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stimulation of microbial activity by N fertilizers which increased mineraliza-
tion of soil N, thus making more soil N available for use by plants.
72-73:020-136
CROP RESIDUE, SOIL WATER, AND SOIL FERTILITY RELATED TO SPRING WHEAT PRODUCTION
AND QUALITY AFTER FALLOW,
Black, A. L.
United States Department of Agriculture, Sidney, Montana.
Soil Science Society of America Proceedings, Vol. 37, No. 5, p 754-758,
September-October, 1973. 1 fig, 5 tab, 19 ref.
Descriptors: ^Cultivation, ^Fallowing, Organic matter, Mulching, Fertilizers,
Nitrogen, Phosphorous, Proteins, Wheat.
Over an 8-year period, wheat straw mulch rates of 0, 1,680, 3,360, and 6,730
kg/ha were established each spring on the fallow year in alternate crop-
fallow blocks in three replications on a Dooley sandy loam. Fertilizer subplot
treatments applied before seeding spring wheat were as follows: Check, N, P,
and N plus P. Both elements were applied at a rate of 34kg/ha; N was applied
each crop year, and P was applied initially and every other crop year there-
after. After 14 and 21 months of fallow, average available soil water stored
to a depth of 1.5 m increased significantly and was positively correlated with
increasing residue levels. Each metric ton of surface residue increased aver-
age available soil water supplies 0.5 cm. Mean grain yields were positively
correlated with stored soil water at seeding only when both N andP were
applied. N-P fertilization increased mean grain yields 410, 580, 690, and 760
kg/ha per year for corresponding residue levels of 0, 1,680, 3,360, and 6,730
kg/ha respectively.
72-73:020-137
* MULCH AND TILLAGE RELATIONSHIPS IN CORN CULTURE,
Van Doren, D. M., Jr., and Triplett, G. B., Jr.
Ohio Agricultural Research and Development Center, Wooster.
Soil Science Society of America Proceedings, Vol. 37, No. 5, p 766-769,
September-October, 1973. 4 tab, 10 ref.
Descriptors: Cultivation, *Mulching, *Organic matter, Corn, Water
Relative effects of soil mulch cover and various tillage practices on corn
yield were studied as functions of previous crop and rainfall on a typic
fragiudalf soil. Residues were removed from the soil prior to tillage,
manipulated according to action of the tillage implements, or replaced on the
soil surface after tillage. Eight tillage treatments consisted of all possible
combinations of moldboard plowing, disking, and post emergence cultivation.
Mulch cover produced three times as great a yield effect as any other single
variable. Tillage variables increased yield in order of cultivation > plow
> disk, and results are expressed in terms of mulch cover required to produce
an equal yield effect. Most tillage and mulch effects were additive. The
major reason for mulch and tillage effects on corn yield is assumed to be
their influence on soil water content. Possible extrapolation of these
results to other soils and climates is discussed.
72-73:020-138
MICRO-DETERMINATION OF CATION-EXCHANGE CAPACITY BY NEUTRON ACTIVATION ANALYSIS,
114
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)udas, M. J.
regon State University, Agricultural Experiment Station, Corvallis.
Boil Science Society of America Proceedings, Vol. 37, No. 5, p 804-805,
^eptember-October, 1973. 1 fig, 2 tab, 4 ref.
sscriptors: *Cation exchange, *Gamma rays, Clays,Kaolinite, Montmorillonite.
Neutron activation analysis was evaluated as a method to determine the cation-
ezchange capacity (CEC) of clay samples. Cation-exchange capacity values of
satisfactory reproducibility and accuracy were obtained on 5- to 50-mg sub-
saiples of a kaolinite and montmorillonite clays previously saturated with Na,
Rb or Cs. Use of Cs as the index ion provided the simplest and most flexible
conditions for the activation analysis method.
72i-73:02G-139
DETERMINATION OF EQUIVALENT RADII FOR RECTANGULAR DRAINS,
Warrick, A. W.
Arizona University, Department of Soils, Water and Engineering, Tucson.
Soil Science Society of America Proceedings, Vol. 37, No. 5, p 809-811,
September-October, 1973. 2 fig, 8 ref.
Descriptors: *Drainage, *Subsurface drainage, Tile drainage, Drainage systems,
Drains, Drainage practices, Drainage engineering.
A relationship is developed giving the circular drain size which is equivalent
to a rectangular drain. A rectangular drain may result when a highly permeable
envelope of rectangular cross-section is used around a buried drainage tube.
A plot of re/square root of (ab) is given as a function of a/b with re as the
circular drain radius and a and b the semi-width and semi-height of the rectan-
gular drain. The minimum value of re/square root of {ab) is 1.18 and corres-
ponds to a square. The equivalent radius is useful in adapting drainage formu-
las giving spacings, depth, etc., to rectangular drains.
72-73:026-140
A MODIFIED ION EXCHANGE TECHNIQUE FOR THE DETERMINATION OF STABILITY CONSTANTS
OP METAL-SOIL ORGANIC MATTER COMPLEXES,
Ardakani, M. S., and Stevenson, F. J.
California University, Department of Soils and Plant Nutrition, Berkeley.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 884-890,
November-December, 1972. 7 fig, 6 tab, 19 ref.
Descriptors: Ion exchange, Humic acids, Humus, Chelation.
Calculation methods based on Schubert's ion-exchange equilibrium method were
developed for determining stability constants of metal-soil organic matter
complexes. The methods, which were free of certain assumptions and errors
inherent in the ion-exchange technique as applied previously to soil organic
matter, were verified using Mn(II)-citrate and Mn(II)-oxalate systems. Apparent
stability constants (log K) of Zn (Il)-humic acid complexes ranged from 3.13
to 5.13 at pH 6.5.
72-73:02G-141
EFFECT OF PHOSPHATE SALTS AS SATURATING SOLUTIONS IN CATION-EXCHANGE CAPACITY
DETERMINATIONS,
115
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Schalscha, E. B., Pratt, P. F., Kinjo, T., and Amar A. J.
Chile University
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 912-914,
November-December, 1972. 3 tab, 19 ref.
Descriptors: *Cation exchange, *Soil chemistry. Salinity, Phosphates,Soil
physics, Saline soils.
Cation-exchange capacities with KCl or NaN03 in volcanic ash soils varied from
6 to 18 meq/100 g whereas CEC with KH2PO4 varied from 78 to 188. Cation-
exchange capacities with NaH2PO4 and NaNO3 were 28 and 6, respectively, for an
alfisol and 12 and 2, respectively, for an oxisol. The ratios of CEC with
H2PO4(-) as compared to Cl(-) or NO3(-) varied from about 4 to 30. The effect
of the H2PO4(-) is explained as a result of neutralization of positive charge
in the soil with a simultaneous release of negative charge.
72-73:020-142
RATES OF GROWTH AND NUTRIENT UPTAKE OF IRRIGATED CORN AS AFFECTED BY N AND P
FERTILIZATION,
Bar-Yosef. B., and Kafkafi, U.
The Volcani Center, Division of Soil Chemistry and Plant Nutrition, Bet Dagan,
Israel.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 931-936,
November-December, 1972. 1 fig, 7 tab, 23 ref.
Descriptors: *Nutrient removal, *Nutrient requirements, *Corn, Phosphorus,
Nitrogen, Fertilizers, Soil chemistry.
Growth rates of corn and weekly uptake of major nutrients were measured in a
permanent plot fertilization experiment. Bicarbonate-soluble P and NO3-N
concentration in the soil were measured four times during the growing period.
High levels of nitrates in the soil during the first month of growth suppressed
dry matter production. An increase in soil phosphate concentration resulted
in higher phosphate uptake and early appearance of male flowers. On the control
plots, which had not received any phosphatic fertilizer for 8 years, the plants
took up more phosphate than the amount estimated by the bicarbonate method.
The high levels of nitrates found in the soil 4 weeks after seeding dropped
within the fifth week to a level of 20-10 ppm N. Denitrification to gaseous
compounds in the presence of living plants due to 68 mm of sprinkler-applied
water is proposed as an explanation of this phenomenon.
72-73:020-143
DETERMINATION OF TOTAL PHOSPHOROUS IN SOILS: A RAPID PERCHLORIC ACID DIGESTION
PROCEDURE,
Sommers, L. E., and Nelson, D. W.
Purdue University, Agricultural Experiment Station, Lafayette, Indiana.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 902-904,
November-December, 1972. 4 tab, 17 ref.
Descriptors: *Fertility, *Phosphorous, Phosphates,Nutrients, Soil chemical
properties, Soil properties, Topsoil.
Extraction and colorimetric methods were evaluated for determining total P
in soils. A procedure involving simultaneous digestion of 60 soil samples with
perchloric acid and determination of extracted orthophosphate with an ascorbic
116
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icid method was evaluated. Analysis of diverse soils indicated that the pro-
posed and conventional HC104 digestion procedures yielded essentially the same
(otal P values; however, both HC104 methods underestimated total P by 1-6%
tien compared to Na2CO3 fusion. A comparison of colorimetric orthophosphate
ocedures indicated the method of Murphy and Riley (1962) was suitable for
determination of orthophosphate following either HC104 digestion of Na2C03
fusion. Determination of total P in soils by tube HC104 digestion and estima-
tion of extracted P by the method of Murphy and Riley (1962) enables rapid and
precise estimation of total P in a wide range of soils.
72-73:020-144
GROWTH, MINERAL COMPOSITION, AND SEED OIL OF SESAME AS AFFECTED BY BORON AND
EXCHANGEABLE SODIUM,
Yousif, Y. H., Bingham, F. T., and Yermanos, D. M.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 923-926, Novem-
ber-December, 1972. 2 fig, 3 tab, 17 ref.
Descriptors: *Salinity, *Alkali soils, Sodium, Boron, Chemical properties,
Soil chemistry. Saline soils, Salts.
A solution culture boron experiment was conducted with sesame to show the
effects of excessive B. The boron content of leaf blades, petioles, and stems
was highly correlated with substrate boron. The leaf blades contained the
highest amount of boron, and the stems the least. Concentrations of 5 mg B/lit-
er or higher inhibited growth, seed production, and resulted in a leaf necrosis
and premature leaf drop. Foliage of plants receiving excess B contained less
micrograms B/g on a dry weight basis. An exchangeable sodium experiment using
clay soil with and without a synthetic soil conditioner showed that yields
were sharply reduced at an ESP level of 15 or greater. Leaf blade sodium was
higher for the treatments without the soil conditioner but in both series,
50% growth depression was associated with leaf values of about 0.4% Na.
Potassium and Mg in the leaf blades did not vary significantly, and although
calcium was decreased 50% with increasing ESP, no visual deficiency symptoms
were detected.
72-73:02G-145
CALCIUM, MAGNESIUM, AND POTASSIUM SATURATION RATIOS IN TWO SOILS AND THEIR
EFFECTS UPON YIELDS AND NUTRIENT CONTENTS OF GERMAN MILLET AND ALFALFA,
McLean, E. O., and Carbonell, M. D.
Ohio State University.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 927-930,
November-December, 1972. 3 tab, 16 ref.
Descriptors: *Salinity, Saline soils, Nutrients, Calcium, Magnesium, Potassium,
Alfalfa, Crop response.
A greenhouse study involving sequential cropping of two soils of differing ca-
tion exchange capacities with five Ca-Mg saturation ratios at two K levels
was conducted. German millet followed by alfalfa was grown with Mg-Ca satura-
tions varied from Mg 5%-Ca 75% to Mg 25%-Ca 55% at two K levels. German
millet yields were not affected in the above range of Ca-Mg saturations.
However, an apparent Mg response occurred when alfalfa yields were more than
doubled by increasing initial Mg and Ca saturations from 3 and 18% to 5 and
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7596, respectively. Exchangeable Mg and Ca contents in the soils after cropping
plus amounts removed by cropping were less than the initial contents in one
soil and were more than the initial contents in the other. Evidently some type
of fixation mechanism tied up Mg and Ca in the former while solubilization of
residual lime released them in the latter.
72-73:026-146
VERTICAL MULCH EFFECTS ON SOIL WATER STOPAGE,
Fairbourn, M. L., and Gardner, H. R.
Agricultural Research Service, Fort Collins, Colorado, Soil and Water Conserva-
tion Research Division.
Soil Science Society American Proceedings, Vol. 36, No. 5, p 823-827, 1972.
Illus.
Identifiers: Diffusivity, Evaporation,*Mulch, *Soil-water storage, Watersheds,
Infiltration, *Soil treatments.
Soil water storage for vertical mulch and furrow treatments on level soil
surfaces and vertical mulch and nonmulch treatments with microwatersheds was
evaluated in a constant temperature laboratory. The vertical mulch treat-
ment on a level surface saved 30-40% more of the applied water than the furrow
treatment. The efficiency of storage with vertical mulch was reduced by 17%
when the surrounding soil surface was wet during water application. A micro-
watershed with vertical mulch stored 7-10% more of the applied water than a
microwatershed without mulch. Depth of water infiltration and dry soil surface
adjacent to the mulch appeared to be the factors that reduced evaporation
losses from vertical mulch treatments. A comparison of scaled evaporation
data with the diffusivity curve for the soil used demonstrated that the diffusiv-
ity equation was useful for predicting soil water loss by evaporation for micro-
watershed treatments of this experiment.
72-73:02G-147
INTERACTING DIFFUSE LAYERS IN MIXED MONO-DIVALENT IONIC SYSTEMS,
Bresler, E.
The Volcani Center, Agricultural Research Organization, Bet Dagan, Israel.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 891-896,
November, 1972. 7 fig, 1 tab, 19 ref.
Descriptors: *Cation exchange, *Cations, Analog computers, Computer models,
Ion exchange.
A numerical solution of the electric double-layer problem for the case of over-
lapping diffuse layers in mixed monovalent-divalent ion systems, is used to
obtain a series of graphs for various cation compositions in the external solu-
tion. In these graphs, the electric potential is expressed as a function of
the surface charge density, the concentration of the two cations in the
equilibrium solution, and the distance between platelets in various ionic
mixtures. The graphs cover most of the situations usually encountered in soil
systems, and are not sensitive to the valency of the anions present. They are
used to estimate pressures, and electrokinetic phenomena in mixed-ion clay
systems. Application of these estimates to theoretical models and experimental
data are illustrated. Some of the examples used for this illustration are
based on work previously published by others.
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72-73:020-148
SPECTROPHOTOMETRIC DETERMINATION OF SOIL WATER CONTENT,
Bowers, S. A., and Smith, S. J.
United States Agricultural Water Quality Management Laboratory, Durant, Okla-
homa.
Soil Science Society of America Proceedings, Vol. 36, No. 6, p 978-980,
November-December, 1972. 2 fig, 1 tab, 9 ref.
Descriptors: *Soil moisture, *Soil moisture meters, Spectrophotometry, Measure-
ment.
The absorbance at 1.94 microns by a soil-methanol extract was used for measuring
the soil water contents of three different textured soils. A linear relation
between absorbance and soil water content was adequate for moisture determina-
tions ranging from air dry to the moisture equivalent. For Quincy loamy sand
and Barnes loam soils, calibration based only on laboratory standards was
sufficient. For Houston Black clay, calibration against oven-dry samples was
necessary.
72-73:020-149
WATER TRANSMISSION PROPERTIES OF AN ASPHALT BARRIER,
Palta, J. P., Blake, G. R., and Farrell, D. A.
Minnesota University, St. Paul, Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 36, No. 5, p 709-714, 1972.
Illus.
Identifiers: *AsphaIt barrier. Capillary potential, Discontinuities, Flow,
Soils, *Water transmission, *Steady flow soil columns.
The water transmission properties of an asphalt barrier were studied using
samples taken from a barrier formed in Zimmerman fine sand. Steady flow
experiments using a 9.0-cm diameter soil column showed that water movement
through the barrier was affected by the capillary potentials on both sides of
the barrier if these potentials exceeded a critical value or 'break point1
which ranged from minus 32 to minus 20 cm depending on the flow rate. This
steady value increased from minus 4.3 to minus 1.5 cm when the flow rate was
increased from 0.009-0.058 cm/hr. The hysteretic flow properties of the
barrier are explained using a model based on the following assumptions: flow
occurs mainly through cracks of varying width, and the ratio of the draining
to wetting potentials of the cracks exceeds unity and is independent of crack
size.
72-73:026-150
SATURATED-UNSATURATED SEEPAGE BY FINITE ELEMENTS,
Neuman, S. P.
The Volcani Center, Agricultural Research Organization, Bet Dagan, Israel.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
99, No. HY12, p 2233-2250, December, 1973. 9 fig, 19 ref.
Descriptors: *Porous media, *Flow, *Hydraulics, Saturated soils, Unsaturated
flow. Seepage, Computer models. Mathematical models, Finite element analysis.
A Galerkin-type finite element method is employed to solve the quasilinear
partial differential equations of transient seepage in saturated-unsaturated
porous media. The resulting computer program is capable of handling nonuniform
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flow regions having complex boundaries and arbitrary degrees of local anisotropy.
Flow can take place in a vertical plane, in a horizontal plane, or in a three-
dimensional system with radial symmetry. An arbitrary number of seepage faces
can be considered simultaneously, and the positions of the exit points on these
boundaries are adjusted automatically during each time step. Two examples,
one of seepage through an earth dam with a sloping core and horizontal drainage
blanket, and the other of seepage through a layered medium cut by a complex
topography, are included. These examples indicate that the classical concept
of a free surface is not always applicable when dealing with transient seepage
through soils.
72-73:026-151
INFILTRATION AND ANTECEDENT PRECIPITATION,
Papadakis, C. N., and Preul, H. C.
Michigan University, Ann Arbor, Department of Civil Engineering.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
99, No. HY8, Paper 9940, p 1235-1245, August 1973. 4 fig, 1 tab, 11 ref, append.
Descriptors: *Infiltration, *Antecedent precipitation, *Hortons law, Infiltra-
tion rates, Soil water movement, Infiltrometers.
A simple, inexpensive, and expedient method is presented for determining the
initial infiltration capacity (fo), the decay rate of infiltration (k), and the
constant infiltration capacity (fc) to be used in Horton's equation. The method
consists of performing a series of infiltration tests using flooding-type test
tube infiltrometers for different antecedent precipitation conditions. Horton's
equation is fitted to the available data, thus obtaining values of fo, fc and
k for each test. Daily rainfall records are used, starting at least 2 months
prior to the infiltration tests, to determine the antecedent precipitation
index values corresponding to each test. Curves of antecedent precipitation
index plotted against Horton's constants provide the designer with the proper
values of fo and K for the soil on which infiltration tests were performed
for any specified antecedent condition.
72-73:026-152
RAINFALL EXCESS MODEL FROM SOIL WATER FLOW THEORY,
Smith, R. E., and Chery, D. L., Jr.
Agricultural Research Service, Tucson, Arizona, Southwest Watershed Research
Center.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
99, No. HY9, Paper 9990, p 1337-1351, September 1973. 13 fig, 9 ref, append.
Descriptors: *Rainfall-runoff relationships, *Infiltration, Mathematical models,
Computer programs. Hydraulics, Overland flow, *Soil water movement. Rainfall
intensity, Antecedent precipitation, Precipitation excess, Model studies.
The complex (computer-dependent) solution of the partial differential equation
for unsaturated soil moisture flow equation was used to develop a simple para-
metric description of the performance of a variety of soils under various
rainfall input rates and patterns, and initial moisture contents. This descrip-
tion is expressed in terms of an infiltration model that is dependent on
accumulated soil water. The model is incorporated in a kinematic model of
rainfall-runoff response, and its predictions are compared with those of an
empirical model of infiltration developed by the USDA Hydrograph Laboratory.
The results emphasize the practical utility of the model and its potential
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advantages over comparable empirical models as well as the inadequate sensitiv-
ity of equipment currently used to measure rainfall and runoff from small
plots.
72-73:026-153
RELATION BETWEEN EVAPOTRANSPIRATION RATE AND MAIZE YIELD,
Hillel, D., and Guron, Y.
Hebrew University of Jerusalem, Department of Agriculture, Rehovot, Israel.
Water Resources Research, Vol. 9, No. 3, p 743-748, June, 1973. 2 fig, 1 tab,
19 ref.
Descriptors: irrigation practices, *Crop response, *Evapotranspiration,
Consumptive use. Water requirements, Corn, Efficiencies.
Water use efficiency is evaluated in terms of the ratio of dry matter yield to
seasonal evapotranspiration. A 5-year maize irrigation experiment was conduct-
ed in which the root zone soil moisture balance and crop response were measured
in relation to potential and actual evapotranspiration. A threshold evapo-
transpiration of 250-300 mm was indicated below which production was negligible
and above which production rose linearly with the amount of water applied.
Water use efficiency increased with higher quantities of irrigation provided
that soil aeration was not impeded and potential evapotranspiration was not
exceeded. It is concluded that a 'wet1 irrigation regime, permitting the drop
to transpire at a rate approaching the climatically induced potential and
simultaneously preventing the occurrence of moisture deficits, can help to
realize the full productivity of the crop.
72-73:020-154
UNSATURATED FLOW PROPERTIES USED TO PREDICT OUTFLOW AND EVAPOTRANSPIRATION
FROM A SLOPING LYSIMETER,
Scholl, D. G., and Hibbert, A. R.
United States Department of Agriculture, Forest Hydrology Laboratory, Tempe,
Arizona.
Water Resources Research, Vol. 9, No. 6, p 1645-1655, December, 1973. 12 fig,
6 ref.
Descriptors: *Lysimeters, *Runoff, *Drainage, Evapotranspiration, Grasses,
Forest soils, Forest watersheds. Forestry.
Field measurements of soil moisture content and pressure potential were used to
determine the moisture flux, hydraulic gradients, and dynamic conductivity of a
200-foot sloping soil lysiraeter. These measurements were then used to predict
outflow and evapotranspiration. A vertical unsaturated Darcian analysis was
used to evaluate conductivity during the first study phase, in which evapo-
transpiration was eliminated by sealing the model surface with a plastic
sheet. The moisture flux term in the Darcy equation was determined by evalu-
ating moisture content change in depth and time. Moisture flux determined in
this was agreed with measurements of actual outflow. Conductivities were
solved from; flux and hydraulic gradients, and corresponding water contents were
assigned. Conductivity curves were highly significant and agreed with those
obtained when the model was uncovered. Evapotranspiration was solved during
the second study phase (cover removed and grass established) by using a water
balance based on moisture content and potential, rainfall, and conductivity
(from the first study phase). Results at the deepest levels in the profile
agreed well with those based on actual outflow.
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72-73:020-155
WATER TABLE MOVEMENT DURING SUBIRRIGATION,
Skaggs, R. W.
North Carolina State University, Biological and Agricultural Engineering
Department, Raleigh.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 5,
p 988-993, September- October, 1973. 10 fig, 18 ref.
Descriptors: ^Irrigation practices, *Subirrigation, *Water table, Mathematical
models, Computer models, Drainage, Irrigation systems, Irrigation design.
The movement of the water table for subirrigation conditions was characterized
by numerically solving a nonlinear differential equation describing unsteady
flow above a horizontal impermeable layer. Solutions were presented for both
initially draining and horizontal water table profiles. Approximate solutions
were derived and compared to the numerical results. The effect of water
loss by evapotranspiration and deep seepage on the water table rise during
subirrigation was also determined by numerical methods. It was concluded that
an approximate solution can be used to reliably predict the movement of the
water table midway between drains.
72-73:020-156
CONTROLLING AUTOMATED IRRIGATION WITH SOIL MATRIC POTENTIAL SENSOR,
Phene, C. J., Hoffman, G. J., and Austin, R. S.
United States Department of Agriculture, Coastal Plains Soil and Water Conser-
vation Research Center, Florence, South Carolina.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 4,
p 773-776, July-August, 1973. 7 fig, 7 ref.
Descriptors: ^Irrigation, *Automatic control. Soil moisture, Moisture meters,
Moisture tension, Moisture availability, Crop response, Moisture content.
Soil water.
The successful use of a soil matric potential sensor to control automatic
irrigation has been demonstrated in both the laboratory and the field. The
soil matric potential in a soil-plant system was controlled automatically at
-0.15 +0.01 bar in the laboratory when the system was subjected to variable
temperatures. Irrigations were also controlled automatically at -7.6 +0.5
bars in a soil-plant system. In the field, the soil matric potential at the
15-cm depth was automatically controlled at -0.21 +0.05 bar and -0.27 +0.03
bar in plots planted to sweet corn. The fluctuation of the soil matric potent-
ial measured could have been further reduced by increasing the duration of water
application at each irrigation. This in no way reflects on the capability of
the sensor to control the irrigation system. The sensor called for irrigation
when water was needed.
72-73:020-157
REMOTE SENSING OF FALLOW SOIL MOISTURE BY PHOTOGRAPHY AND INFRARED LINE SCANNER,
Allen, W. H., and Sewell, J. I.
Mississippi State University, Agricultural and Biological Engineering Depart-
ment, Starkville.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 4,
p 700-706, July-August, 1973. 5 fig, 3 tab, 14 ref.
Descriptors: *Remote sensing, *Soil moisture, Fallowing, Infrared radiation,
Environmental engineering. Soil water, Soil science, Soil physics.
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A laboratory investigation of the relationship between reflectance of bare soil
and soil moisture level at wavelengths throughout the visible and into the near
infrared was implemented. A definite relationship was found between soil
moisture and reflectance. This was adequately described by a quadratic func-
tion. Remote sensing appears to be potentially valuable in environmental
analysis associated with soil moisture conditions. A definite need remains
for further definition and evaluation of the basic relationship as well as the
inclusion of more related variables.
72-73:020-158
EXPERIMENTAL EVALUATION OF A METHOD FOR DETERMINING UNSATURATED HYDRAULIC
CONDUCTIVITY,
Skaggs, R. W., Monke, E. J., and Huggins, L. F.
North Carolina State University, Biological and Agricultural Engineering
Department, Raleigh.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 1,
p 85-88, January-February, 1973. 9 fig, 17 ref.
Descriptors: *Soil moisture, *Soil water, Soil water movement, Unsaturated
flow, Hydraulic conductivity, Hydraulics, Groundwater movement.
An experimental investigation was conducted to evaluate an approximate method
of determining the hydraulic conductivity function of unsaturated soil. The
method was based on the assumption that the conductivity-pressure head relation-
ship could be effectively represented by an empirical 3-parameter equation
presented by Gardner (1958). The conductivity functions of two artificially
packed soils were determined. Infiltration rate-time relationships were then
measured for infiltration into soil columns having different initial water
content distributions. These relationships were compared to influx curves
predicted through the use of the determined K(h) functions.
72-73:020-159
FIELD EVALUATION OF TRANSIENT DRAIN SPACING EQUATIONS,
Skaggs, R. W., Kriz, G. J,, and Bernal, R.
North Carolina State University, Biological and Agricultural Engineering
Department, Raleigh.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 3,
p 590-595, May-June, 1973. 6 fig, 3 tab, 16 ref.
Descriptors: *Drainage, *Groundwater movement, Drainage practices, Subsurface
drainage, Tile drainage. Soil water movement, Crop response, Irrigation effects.
Field experiments were conducted on a subirrigation-drainage system to determine
the applicability of four drain spacing equations for a shallow sandy loam
soil. The water table drawdowns following subirrigation and rainfall events
were measured for drain spacings of 7.5, 15 and 30 m. Drain spacings were
calculated using four theoretical equations and were compared to the actual
spacings. The results of the experiments show that for soils with shallow
water tables, the application of rainfall will result in a sharp rise in the
water table elevation. The total rise and response time of the water table
will depend on its initial depth, the rate and amount of rainfall, andthe soil
hydraulic properties.
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72-73:020-160
SHALLOW DRAIN PERFORMANCE IN HEAVY SOIL,
Hermsmeier,L. F.
United States Department of Agriculture, Imperial Valley Conservation Research
Center, Brawley, California.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 1,
p 92-94, 96, January-February, 1973. 3 fig, 5 tab.
Descriptors: *Drainage, *Subsurface drainage, Tile drainage, Drainage systems,
Drainage engineering, Drainage area, Drainage programs.
Shallow drains installed at a 4-foot depth and 200-foot spacing in a clay and
loamy clay soil removed only from 12 percent to 7.2 percent of the salt added
by the irrigation water during four cropping seasons over a 2-1/2 year period.
The small amount of salt removed by the drains, when combined with salt
removed from the soil by the natural drainage, was sufficient to maintain a
favorable salt balance. However, during the sugarbeet cropping season when
only 7.2 percent of the salt added by the irrigation water was removed by the
drains there was an unfavorable salt balance in the field. Shallow drains can
provide the means for removing sufficient salt from the soil to maintain a
favorable salt balance when combined with natural drainage and good irrigation
practice.
72-73:020-161
DEVELOPMENT OF AN AGRICULTURAL DRAINAGE GUIDE,
Dickey, G. L., and Johnston, W. R.
United States Department of Agriculture, Soil Conservation Service, Berkeley,
California.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 1,
p 97-99, January-February, 1973. 6 fig, 6 ref.
Descriptors: *Drainage, *Subsurface drainage, Tile drainage. Drainage systems,
Drainage engineering, Drainage area, Drainage programs.
Identifiers: Drainage guide.
A simplified procedure for field investigation and design of subsurface drain-
age systems was developed for western Fresno County, California. Data was
collected to a depth of 20 feet or more in deep soil in order to analyze the
drainage problem. Standard soil surveys to the depth of 5 feet are of little
value in determining drain depth requirements in deep soils; however, a corre-
lation was found between 0 to 5-foot soil characteristics and the drainage
coefficient. Existing drainage systems are needed for study and evaluation.
This allows a drainage guide to be developed on actual drain performance.
72-73:020-162
SOIL CRUSTING RELATED TO SPRINKLER INTENSITY,
Busch, C. D., Rochester, E. W., and Jernigan, C. L.
Auburn University, Agricultural Experiment Station, Auburn, Alabama.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 4,
p 808-809, July-August, 1973. 5 fig, 2 tab, 10 ref.
Descriptors: *Irrigation practices, *Sprinkler irrigation, Soil physics. Soil
cement. Soil management. Soil properties, Soil stability, Soil surfaces, Soil
texture.
Identifiers: Soil crusting.
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It was found that crust strengths developed under two different sprinkling
intensities persist over three wetting and drying cycles. Lower sprinkler
application rates consistently produced a weaker crust. Increasing the number
of water application cycles did not show a consistent effect on crust strength.
Previous sprinkling may reduce the strength of a crust formed by a subsequent
rainfall.
72-73:020-163
GRAIN SORGHUM RESPONSE TO TRICKLE AND SUBSURFACE IRRIGATION,
Hiler, E. A., and Howe11, T. A.
Texas A & M University, Agricultural Engineering Department, College Station.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 4,
p 799-803, July-August, 1973. 5 fig, 3 tab, 18 ref.
Descriptors: *Irrigation, *Surface irrigation, "Subsurface irrigation,
Distribution systems, Irrigation systems, Mist irrigation, Lysimeter, Water
utilization, Crop response.
Grain sorghum was grown during 1971 and 1972 in a field lysimeter installation
in which control of the soil water could be maintained. Undisturbed soil
cores approximately one meter in diameter and two meters deep made up the
lysimeters. Rainfall was kept off the lysimeters with an automated shelter
system. Irrigation treatments during 1971 included Subsurface, Trickle, Sub-
surface plus Mist, Trickle plus Mist, Mist, and Surface. All treatments in-
volving subsurface and trickle irrigation were irrigated every third day in an
amount calculated to bring the soil water content to "field capacity". The
Hist treatment was "overmisted" slightly so that the soil water potential would
be maintained between 0 and -0.7 bar. The Surface treatment was irrigated
when the soil water potential in the root zone reached -0.7 bar in the amount
of 1.1 times measured depletion.
72-73:020-164
AN ECONOMICAL HYDRAULIC WEIGHING EVAPOTRANSPIRATION TANK,
Dylla, A. S. , and Cox, L. M.
United States Department of Agriculture, Agricultural Research Service, Morris,
Minnesota.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 2,
p 294-295, 301, March-April, 1973. 5 fig, 2 ref.
Descriptors: *Lysimeters, *Weight, Evapotranspiration, Instrumentation,
Moisture meters, Moisture content, Soil water. Water loss.
Experimental tests were conducted in 1965-1966 in Nevada on large soil-filled
tanks, 152.5 cm in diameter by 198 cm. deep, supported on 30.5-m lengths of 5-cm
diameter butyl irrigation tubing filled with a water-methanol mixture. The
tubing was coiled to provide about 90 percent bottom area support. The sensi-
tivity of the weighing system of the low-cost butyl tubing-supported ET tanks
is adequate for many evapotranspiration periods. Fabricating the tanks of
plain 2.79-mm thick rolled steel with no special reinforcing or structural
supporting members minimizes costs. The water-filled butyl irrigation tubing
provides a flexible supporting pad that tends to resist imbalanced loads.
Routing all hydraulic pressure lines below ground level to a temperature-con-
trolled manometer pit minimizes thermal error and the need for temperature
corrections. The cylindrical tank also adapts readily to taking undisturbed
and vegetated soil monoliths.
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72-73:02G-165
WATER INTAKE RATES ON A SILT LOAM SOIL WITH VARIOUS MANURE APPLICATIONS,
Cross, O. E., and Fischbach, P. E.
Nebraska University, Agricultural Engineering Department, Lincoln.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 2,
p 282-284, March-April, 1973. 9 fig, 5 ref.
Descriptors: *Irrigation practices, *Permeability, Soil physics. Soil structure,
Soil amendments, Soil density. Soil management. Soil texture, Organic matter.
Feedlot manure was applied to and incorporated into a sharpsburg silt loam
soil. Four levels of manure were applied and the plots disk plowed to three
depths. During 1970 the crops were irrigated three times and during 1971,
four times. Water infiltration rates were determined from data of the inflow-
outflow method. The initial water intake rate increased as the quantity of
manure application increased. The basic water intake rate increased as more
time from date of manure application had elapsed. Manure application decreased
the basic intake rate as compared to the basic intake rate of non-manured silt
loam soil. Depth of plowing did not appreciably affect the basic intake rate.
72-73:020-166
SUBSURFACE DRAINAGE AND IRRIGATION FOR SUGARCANE,
Carter, C. E., and Floyd, J. M.
United States Department of Agriculture, Agricultural Research Service, Baton
Rouge, Louis iana.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 2,
p 279-281, 284, March-April, 1973. 6 fig, 7 ref.
Descriptors: *Irrigation practices, *Subsurface irrigation, *Drainage, Sub-
surface drainage. Tile drainage, Soil water movement, Crop response, Sugarcane.
Water management practices, particularly subsurface drainage, increased annual
sugarcane yields from 24 to 62 percent over those from check plots and increased
the number of crops grown after a single planting from the normal three to five.
No response to irrigation was recorded. Sucrose content of the cane's juice
decreased as cane yields increased. Extra cane produced by the treated plots
more than compensated for the lower percent sucrose; consequently, sugar yields
per acre were higher from the treated plots.
72-73:020-167
ON THE SOLUTION OF TRANSIENT FREE-SURFACE FLOW PROBLEMS IN POROUS MEDIA BY THE
FINITE ELEMENT METHOD,
Cheng, R. T., and Li, C. Y.
State University of New York, Department of Engineering and Applied Sciences,
Buffalo.
Journal of Hydrology, Vol. 20, No. 1, p 49-63, September, 1973. 9 fig, 15 ref.
Descriptors: *Porous media, *Soil physics, *Flow, Free surfaces. Computer
models, Mathematical models, Drainage.
A numerical procedure is presented to deal with solution of transient free-
surface flows in porous media. The governing boundary-value problem for the
piezometric potential is solved by the finite element method. The initial-
value problem which describes the transient motion of the free-surface is solved
by the method of quasi-linearization. The numerical scheme has been applied to
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isotropic and anisotropic earth dam problem and also to a ditch drainage problem,
Excellent agreements have been reached when compared with known solutions.
This computational procedure is shown to be stable and suitable for this class
of problems with the aid of a digital computer.
72-73:020-168
NUMERICAL STUDIES OF TWO-DIMENSIONAL SATURATED/UNSATURATED DRAINAGE MODELS,
Todsen, M.
Oslo University, Institute of Geophysics, Oslo, Norway.
Journal of Hydrology, Vol. 20, No. 4, p 311-326, December, 1973. 10 fig,
15 ref.
Descriptors: *Drainage, *Computer models, Saturated flow, Unsaturated flow,
Groundwater movement. Soil water. Drainage design.
The partial differential equation which governs the seepage of water in unsatur-
ated and saturated porous media is solved numerically by a generalized Newton
iteration technique for two models, one ditch drainage model and one earth
dam model. For each model, which is two-dimensional, a few hypothetical soils
with different moisture retention curves are considered. In both models only
drainage from an initially saturated soil occurs; thus, the problem of hyster-
esis is avoided. The results of the computations are compared with those of
corresponding saturated models; solutions obtained earlier by this author and
others. Computational instability phenomena appear when the slope of the
retention curves is made steep, i.e., for poorly-graded soils.
72-73:026-169
WATER WITHDRAWAL BY PLANT ROOTS,
Feddes, R. A., and Rijtema, P. E.
Institute for Land and Water Management Research, Wageningen, The Netherlands.
Journal of Hydrology, Vol. 17, No. 1/2, p 33-59, October, 1972. 10 fig,
5 tab, 24 ref.
Descriptors: *Soil moisture, *Root systems, *Soil-water-plant relationships,
Absorption, Water utilization, Plant growth, Moisture availability.
An analysis of the transport resistance for liquid flow in the plant as well
as an investigation on the geometry factor of the root system for red cabbage is
presented. The variation of these factors with depth is described, and root
extraction rates at different depths are calculated and compared with data
obtained from water balance studies. The plant resistance data are in reason-
able agreement with existing literature. Because of a non-homogeneous and poor
root development in the early stages of growth, the geometry data of the initial
growing stages differ a factor ten from data found in literature. With root
development increasing with depth, geometry data decrease to values also report-
ed for other crops.
72-73:020-170
SOIL MOISTURE PROFILE UNDER STEADY INFILTRATION,
Lin, S. S., Rochester, E. W., and Hermanson, R. E.
Auburn University, Department of Agricultural Engineering, Auburn, Alabama.
Journal of Agricultural Engineering Research, Vol. 18, No. 3, p 179-187,
September 1973. 8 fig, 2 tab, 4 ref.
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Descriptors: *Soil moisture, *Soil vrater, *Infiltration, Groundwater movement,
Infiltration rates, Permeability, Porosity, Runoff.
Finite difference procedures were applied in the solution of time and space
dependent differential equations describing moisture potential and content.
The problem under consideration was a homogeneous soil profile with a constant
water table at 120 cm. Initially the soil moisture was at static equilibrium.
Constant infiltration was initiated and continued until dynamic equilibrium
was approximated. The resulting moisture content and pressure profiles are
presented graphically for a number of time intervals and relative infiltration
values. Zones of constant moisture content and pressure are discussed.
72-73:020-171
DELAYS IN THE OPERATION OF SUBSURFACE DRAINAGE TRENCHING MACHINES,
Fisk, S. D., Broughton, R. S., and Norris, E. R.
Quebec Ministry of Agriculture and Colonization, Buckingham, Quebec, Canada.
Canadian Agricultural Engineering, Vol. 14, No. 2, p 69-71, December, 1972.
1 fig, 2 tab, 3 ref.
Descriptors: *Drainage, *Trenches, *Construction, Subsurface drainage, Tile
drainage, Installation, Drainage systems, Drainage engineering.
Observations of four, wheel-type, subsurface drainage trenching machines showed
that delays accounted for 53.3-65.9 percent of total working-day time. The de-
lays that appear to be most easily reduced include setting targets (5.7 percent
time loss), making junctions (3.8 percent time loss), and moving to new job
sites (3.7 percent time loss). Based on 174 available working days, the aver-
age effective digging time was an equivalent of only 72 days. By decreasing
these time losses, the operational efficiency of subdrainage trenching can be
improved and considerable savings can be made.
72-73:020-172
PLANT AND IRRIGATION WATER REQUIREMENTS,
Frost, K. R.
Irrigation Journal, Vol. 23, No. 6, p 10, November-December, 1973.
Descriptors: *Soil-water-plant relationships, Crop response, Evapotranspira-
tion. Soil moisture, Soil water, Soil chemistry.
A brief, descriptive outline of the factors affecting crop water use is pre-
sented. A description of the irrigation scheduling processes is given in
simple terms.
72-73:020-173
A LONG-TIME WATER-TABLE STUDY OF AN IRRIGATION PROJECT IN SOUTHERN ALBERTA,
Rapp, E., and van Schaik, J. C.
Canada Agriculture, Research Station, Lethbridge, Alberta.
Canadian Agricultural Engineering, Vol. 14, No. 1, p 29-32, June, 1972. 3 fig,
2 tab, 5 ref.
Descriptors: *Drainage, *Groundwater, *Water table, Drainage, Drainage engi-
neering, Irrigation, Groundwater movement, Soil water.
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Water-table levels were measured for a period of 15 years in the Vauxhall Dis-
trict. The seasonal mean water-table depth was 169 cm with a standard devia-
tion of +10 cm. On the average, 64% of the area had a water table higher than
the accepted standard of 183 cm. Although variability in some Units was high,
mean seasonal water-table data indicate that no serious drainage problem exists
in the Vauxhall District. There was no consistent relationship between irri-
gation water used or the total hydrologic input and the concurrent water-
table depth. This indicates that the water table in the Vauxhall District is
not a direct function of either irrigation or seasonal rainfall on a long-
term basis.
72-73:02G-174
MAXIMUM CORN YIELDS WITH MINIMUM WATER,
Irrigation Age, Vol. 7, No. 10. p 18-20, 22-23, May, 1973. 1 fig, 4 tab.
Descriptors: *Irrigation practices, *Surface irrigation, Soil moisture,
Soil water, Crop response, Corn.
The development of automated irrigation has introduced the possibility of a
new concept to irrigation water management. That is, not completely refilling
the root zone each irrigation; thereby leaving soil moisture storage capacity
within the root zone to take advantage of any rainfall that occurs during the
irrigation season. The old recommendation of refilling the root zone each
irrigation is wasteful in both fertilizer and water. It is wasteful in that
if rainfall occurred soon after the field was irrigated, water would percolate
below the root zone carrying soluble nutrients with it, such as nitrates.
72-73:02G-175
A SIMPLE METHOD OF DRIP IRRIGATION,
DeReraer, E. D.
Agronomics, Incorporated, Avondale, Arizona.
Irrigation Journal, Vol. 22, No. 3, p 10-15, May-June, 1972. 8 fig, 5 ref.
Descriptors: *Irrigation practices, Surface irrigation, Application equip-
ment, Soil moisture, Tensiometers, Evaporation, Crop responses.
Identifiers: Drip irrigation, Irrigation timing.
A simple method for determining when and how much to irrigate using a drip
system has been developed. The only climatological data required is pan
evaporation. The calculations are simple and can be carried out by non-techni-
cal persons. Tensiometers are used to determine when irrigation is needed.
72-73:020-176
CONTROLLING SOIL CRUSTING WITH PHOSPHORIC ACID TO ENHANCE SEEDLING EMERGENCE,
Robbins, C. W., Carter, D. L., and Leggett, G. E.
United States Department of Agriculture, Agricultural Research Service, Snake
River Conservation Research Center, Kimberly, Idaho.
Agronomy Journal, Vol. 64, No. 2, p 180-183, March-April, 1972. 3 tab, 15 ref.
Descriptors: *Soil physics, *Soil aggregates, Soil management. Sugar beets,
Fertility, Phosphorus, Soil structure. Soil treatment.
Identifiers: Soil crusting. Phosphoric acid.
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A study was conducted to determine if spraying dilute phosphoric acid in
narrow bands along the seeded rows would increase sugar beet seedling emergence
by preventing or minimizing soil crusting and provide the needed nutritional
P for crop production. Dilute phosphoric acid was sprayed along rows seeded to
sugar beets on a Portneuf silt loam. Several acid concentrations and P rates
were applied. Stand counts were made before and after thinning, and P concen-
trations were measured in sugar beet petioles sampled at three dates during the
growing season. Laboratory studies were conducted to determine the effects of
the phosphoric acid on soil properties. Applying 69 kg P/ha as dilute phosphor-
ic acid in liquid volumes of 650 to 1,300 liters/ha reduced crusting by in-
creasing aggregate stability in the soil surface, increased sugar beet seedling
emergence, and provided the P needed by the sugar beet crop.
72-73:02G-177
COMBINING EXPERIMENTS TO PREDICT FUTURE YIELD DATA,
Cady, F. B., and Allen, D. M.
Cornell University, Ithaca, New York.
Agronomy Journal, Vol. 64, No. 2, p 211-214, March-April, 1972. 3 fig, 2 tab,
6 ref.
Descriptors: ^Regression analysis, *Yield equations, Soil tests, Fertility,
Fertilization.
Data from a series of fertility experiments including uncontrolled environmental
variables are analyzed so that future yields may be predicted. A new criterion,
the prediction sum of squares, based on the performance of the estimated equa-
tion for predicting observations not included in the least squares estimation,
is developed for selecting the best predictor variables. The procedure gives
an estimated prediction equation with a minimal number of predictor variables,
including few interaction variables. Agronomically reasonable estimates of the
regression coefficients also are obtained. Using the new procedure, a 30%
reduction in the sum of squared deviations between the observed and the pre-
dicted observations compared with the stepwise regression method is found.
Response curves are constructed for use in making soil test recommendations.
72-73:026-178
COMPARATIVE YIELD AND FERTILIZER EFFICIENCY OF NO-TILLAGE AND CONVENTIONALLY
TILLED" CORN,
Moschler, W. W., Shear, G. M., Martens, D. C., Jones, G. D., and Wilmouth, R. R.
Virginia Polytechnic Institute and State University, Blacksburg.
Agronomy Journal, Vol. 64, No. 2, p 229-231, March-April, 1972. 3 tab, 13 ref.
Descriptors: Cultivation, Corn, Fertilization, Fertilizers, Leaching, Nitro-
gen, Phosphorus, Potassium, Efficiencies.
Surface application of fertilizer for no-tillage corn is the most convenient
method. The relative efficiency of fertilizer applied in this manner has been
undetermined, however. Field experiments on three soil types in Virginia
suggest that fertilizer efficiency for no-tillage corn with surface application
was higher than for conventionally tilled corn with an equal disked-in applica-
tion. No-tillage resulted in a 9-year average yield increase of 25.6% on Lodi
silt loam, a 6-year average increase of 13.7% on Davidson clay loam, and a
5-year average increase of 39.096 on Cecil clay loam. In addition to increased
yields, larger amounts of residual N, P, and K, as well as organic matter, were
found in no-tillage soil in several cases.
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72-73:020-179
INFLUENCE OF SALINITY ON FE, MN, AND ZN UPTAKE BY PLANTS,
Maas, E. V., Ogata, G., and Garber, M. J.
United States Salinity Laboratory, Riverside, California.
Agronomy Journal, Vol. 64, No. 6, p 793-795, November-December 1972. 3 fig,
10 ref.
Descriptorss *Salinity, *Crop response, Crop production, Tomato, Soybean,
Nutrients, Nutrient removal, Hydroponics.
This investigation was conducted to determine the influence of salinity on the
uptake of Fe, Mn, and Zn by plants during the period of rapid vegetative growth,
Relatively few data are available on the micronutrient status of salt-stunted
plants. Tomato, soybean, and squash were grown in the greenhouse in half-
strength Hoagland's solution salinized with 0, 25, 50, 75, and 100 meq Nad/
liter. Concentrations of Fe and Zn increased in the roots and tops of each
species with increasing ambient levels of NaCl. Manganese concentrations
increased in tomato and soybean tops but decreased in squash tops. Concen-
trations of Mn in the roots of tomato and squash were reduced at all salt
levels, but they increased in all but the 100 meg/liter treatment in soybean.
The changes in contents as a function of salinity were in the order of two-
fold or less and all were significant at the 5% level or better.
72-73:020-180
RESPONSE OF IRRIGATED CORN TO TIME, RATE, AND SOURCE OF APPLIED N ON SANDY
SOILS,
Jung, P. E., Jr., Peterson, L. A., and Schrader, L. E.
Wisconsin University, Agronomy Department, Madison.
Agronomy Journal, Vol. 64, No. 5, p 668-679, September-Oatober, 1972. 6 tab,
6 ref.
Descriptorst *Fertilization, *Nitrogen, *Crop response, Corn, Nutrient removal,
Nitrogen compounds, Fertility.
Three sources of N were applied to corn at four rates and six times of appli-
cation in all combinations. 'Wisconsin 273' and 'Wisconsin 433' corn were
grown. Response was measured as grain yield, tissue yield, percentage N in
tissue, percentage N in grain, and N uptake. The N applied during either the
5th, 6th, 7th, or 8th week after planting was the most effective as shown by
increased grain and tissue yields. Nitrogen applied after the 8th week was
associated with a distinct reduction in N uptake and grain and tissue yields.
Generally, percentage N in the grain and tissue increased with later N appli-
cation. Nitrate reductase (NR) activity in the leaves and percentage N in
grain and tissue increased with increasing rate of applied N. Yields of
grain and tissue for Wisconsin 273 and Wisconsin 433 leveled off at the 112
and 168 kg/ha rates of N, respectively.
72-73:026-181
NITRATE-N ACCUMULATION IN THE SOIL PROFILE UNDER ALFALFA,
Schertz, D. L., and Miller, D. A.
University of Illinois, Agronomy Department, Urbana.
Agronomy Journal, Vol. 64, No. 5, p 660-664, September-October, 1972. 7 fig,
4 tab, 10 ref.
Descriptors: *Nutrient removal, *Nitrates, *Alfalfa, Leaching, Water pollution
131
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sources. Rotations, Crop production, Crop response.
Eight split applications of N totaling 0, 224, 448, and 672 kg/ha (0, 200,
400, and 600 pounds/acre) were studied at the Agronomy South Farm, Urbana,
Illinois, at various depths on six sampling dates. Soil was sampled at depths
of 0 to 15, 15 to 30, 30 to 60, 60 to 90, and 90 to 105 cm or to the water
table, which was never lower than 105 cm. Soil samples were dried, finely
ground, and analyzed for nitrate nitrogen. Nitrate nitrogen concentrations
were greatest in March 1970 at the 30- to 60-cm depth. No more than 1 ppm
was found at the 90- to 105-cm depth (water table) for any N treatments on
November 11, 1970. Highest concentrations of nitrate nitrogen were found at
the 15- to 30-cm depth for all N treatments at the end of the growing season,
November 11. Although total amounts of nitrate nitrogen were lower in March
than in November, the highest accumulations were found at the 30- to 60-cm
depth in March, but at the 15- to 30-cm depth in November. The only treatment
on November 11 that did not show a significant difference when compared to the
check was the 224 kg N/ha.
72-73:02G-182
EFFECT OF HIGH RATES OF N, P, K FERTILIZER ON CORN GRAIN YIELDS,
Powell, R. D., and Webb, J. R.
Wisconsin University, Department of Soil Science, Madison.
Agronomy Journal, Vol. 64, No. 5, p 653-656, September-October, 1972. 3 fig,
4 tab, 13 ref.
Descriptors: *Fertility, *Crop response, *Corn, Nitrogen, Phosphorus, Potassium,
Nutrient removal, Crop production.
Annual applications of high rates of N, P, and K fertilizer to Clarion-Webster
Soil Association soils in central and north central Iowa planted to corn
produced variable yield results. Incremental rates of N, P, and K fertilizers
up to 1,344, 504, and 1,008 kg/ha, respectively, were applied annually for 3
consecutive years. The grain yields were analyzed statistically using analyses
of variance and regression techniques. Three regression functions, a second
order quadratic, a logarithmic to the base e, and a square root function were
used to estimate the response surfaces and compared for goodness of fit. The
yields were the dependent variable and the applied fertilizer nutrients were
the independent variables.
72-73:020-183
INFLUENCE OF SUBSURFACE BARRIER ON GROWTH, YIELD, NUTRIENT UPTAKE, AND WATER
REQUIREMENT OF RICE,
Rao, K. V. P., Varade, S. B., and Pande, H. K.
Indian Institute of Technology, Department of Agricultural Engineering,
Kharagpur, India.
Agronomy Journal, Vol. 64, No. 5, p 578-580, September-October, 1972. 5 tab,
7 ref.
Descriptors: *Barriers, *Rice, *Nutrient removal. Crop response, Leaching,
Fertility, Fertilization, Crop production.
Growth of rice under flooded conditions in Southeast Asia results in excessive
water and N losses. This investigation was conducted to determine the effect
of subsurface barriers of bitumen and concrete on yields of rice grown with 60,
90, and 120 kg/ha of N. Yields of rice grown over the subsurface barriers
132
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were significantly higher than those grown on the control. The increase in
growth and yield of rice was attributed to increased uptake of N, P, and Fe
rendered available due to conducive redox potential. Rice produced signifi-
cantly higher yields with 90 to 120 kg/ha of N than with 60 kg/ha. Subsurface
barriers reduced the water requirement drastically and increased water use
efficiency.
72-73:020-184
INFLUENCE OF CROPPING SYSTEM ON SALT DISTRIBUTION IN AN IRRIGATED VERTISOL,
Hipp, B. W., and Gerard, C. J.
Texas A & M University, Agricultural Research and Extension Center, Weslaco.
Agronomy Journal, Vol. 65, No. 1, p 97-99, January-February, 1973. 3 fig,
3 tab, 6 ref.
Descriptors: *Salinity, *Leaching, Cotton, Grain sorghum, Infiltration rates,
Saline water, Saline soils.
Field studies were conducted to determine the influence of cotton and grain
sorghum on salt distribution in a vertisol profile. Electrical conductivity
of soil saturated pastes taken from the root zone (0 to 90 cm) after 4 years of
sorghum ranged from 2.6 to 4.8 mmhos/cm but ranged from 4 to 7.6 mmhos/cm at
0 to 90 cm after 4 years of cotton. Chloride concentrations showed similar
trends in that Cl- concentrations were 9 to 12 meq/liter at 0 to 90 cm after
sorghum, but were from 18 to 30 meq/liter at the same depth after cotton. The
differences in salt concentrations in the soil profile after the two crops
were attributed mainly to higher water infiltration rate after sorghum than
after cotton. The data indicate that cropping practice can be an important
factor in salt accumulation in clay soils and that the crops should be alter-
nated to avoid excessive salt accumulation in the root zone.
72-73:020-185
INFLUENCE OF FERTILIZER PLACEMENT ON YIELD RESPONSE OF SOYBEANS,
Ham, G. E., Nelson, W. W., Evans, S. D., and Frazier, R. D.
Minnesota University, Soil Science Department, Saint Paul.
Agronomy Journal, Vol. 65, No. 1, p 81-84, January-February 1973. 2 fig, 3
tab, 11 ref.
Descriptors: *Fertility, *Fertilizers, *Crop response, Nitrogen, Phosphorus,
Potassium, Soybeans.
Fertilizer treatments consisting of banded started, starter in contact with the
seed, and a combination of banded and seed placement were superimposed on
broadcast fertilizer treatments at three locations. Responses varied depending
on environmental factors. With low rainfall and a low soil test P level, the
largest response was from broadcast fertilizer. Starter fertilizer had less
effect on seed yields either with or without broadcast fertilizer even though
both starter and broadcast effects were significant. With adequate rainfall and
a low P level, the largest response was to combinations of starter and broad-
cast fertilizer. Yields were increased by as much as 746, 598, and 941 kg/ha
with band, seed placement and broadcast treatments, respectively. When P and K
levels were very high, no yield increases were obtained from any fertilizer
placement. In fact, seed placement without broadcast or seed placement and/or
band in combination with broadcast decreased yields significantly in many cases.
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72-73:02G-186
SIMULATION OF DROUGHT AND ITS EFFECT ON GERMINATION OF FIVE PASTURE SPECIES,
Sharma, M. L.
Commonwealth Scientific and Industrial Research Organization, Rangeland Re-
search Unit, Riverina Laboratory, Deniliquin, New South Wales, Australia.
Agronomy Journal, Vol. 65, No. 6, p 982-987, November-December, 1973. 3 fig,
24 ref.
Descriptors: *Osmotic pressure. Drought tolerance, Dry farming, Pastures,
Salinity.
While studying the effect of drought on seed germination, water potentials are
usually simulated by addition of various osmotic substrates to water. Studies
showing the comparative effects of these simulated water potentials of true
drought are rather scarce. A study was undertaken whereby drought was simulated
by sodium chloride (Nad), mannitol, and polyethylene glycol (PEG, 20,000
mol wt.). These osmotic drought effects were compared with those of true
drought. The rate and total germination of all the species declined with
decreasing levels of water potential. The extent of such reduction varied
considerably among species and with the type of osmotic medium. On iso-
potential basis, the order of osmotic medium with respect to the severity of
their effect on germination reduction in all the species was PEG>NaCl>tnannitol.
It was suspected that both Nad and mannitol entered the seeds, and also that
the toxic effects of NaCl were either equally or dominantly offset by the
solute entry effects.
72-73:020-187
EFFECT OF TEMPERATURE AND PLANT WATER STRESS ON PHOTOSYNTHESIS DIFFUSION
RESISTANCE, AND LEAF WATER POTENTIAL IN SPRING WHEAT,
Frank, A. B., Power, J. F., and Willis, W. O.
Northern Great Plains Research Center, Mandan, North Dakota.
Agronomy Journal, Vol. 65, No. 5, p 777-780, September-October, 1973. 4 fig,
3 tab, 19 ref.
Descriptors: *Soil moisture, *Crop response, *Wheat, Stress, Soil-water-
plant relationships, Droughts, Salinity.
A study was conducted in growth chambers to determine the combined effects of
temperature and soil water supply on the development of plant water stress
and subsequent recovery in spring wheat. Measurements were made of leaf water
potential, photosynthesis, and stomatal diffusion resistance on the fifth
leaf at tillering and the flag leaf at heading, flowering, and grain-filling
growth stages for plants grown at 10, 18, and 27C. Stomatal closure of
stressed plants was affected by both leaf position and age. Closure occurred
at -13, -13, and -15 bars leaf water potential at tillering and at -18, -17,
and -26 bars at heading for 10, 18, and 27C, respectively. As the flag leaf
matured, stomata closed at progressively lower leaf water potential. In non-
stressed check plants, temperature greatly influenced leaf water potentials.
72-73:026-188
TOLERANCE OF RICE TO SALT DURING BOOT, FLOWERING, AND GRAIN-FILLING STAGES,
Kaddah, M. T., Lehman, W. F., and Robinson, F. E.
United States Department of Agriculture, Agricultural Research Service, Imperial
Valley Conservation Research Center, Brawley, California.
Agronomy Journal, Vol. 65, No. 5, p 845-847, September-October, 1973. 1 fig,
14 ref.
134
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Descriptors: *Salinity, *Crop response, *Rice, Soil moisture, Stress, Crop
production.
The effect of soil salinity on rice development at the boot, flowering, and
grain-filling stages was tested for three varieties transplanted in a green-
house. The irrigation waters used had electrical conductivities of 1.4, 3.0,
and 6.0 mmho/cm at 25C. The last two irrigation waters were introduced at the
three stages of development and used until harvest. Weights of grain and
straw and lengths of plants and panicles did not differ significantly between
the treatments, indicating that rice is not sensitive to salt after the boot
stage.
72-73:020-189
INFLUENCE OF TEMPERATURE AND MOISTURE STRESS FROM SODIUM CHLORIDE SALINIZATION
ON OKRA EMERGENCE,
Albregts, E. E., and Howard, C. M.
Florida University, Agricultural Research Center, Dover.
Agronomy Journal, Vol. 65, No. 5, p 836-837, September-October, 1973. 1 tab,
7 ref.
Descriptors: *Soil moisture, *Stress, Salinity, Crop response, Crop production.
Okra seed were planted in a Scranton fine sand soil at 20, 25, and 30 C with
six levels of moisture stress, 1.18, 1.75, 2.41, 4.33, 5.90, and 10.84 atm.
Moisture stress was obtained by varying the moisture level in the soil and by
Nad salinization. The emergence rate and fresh plant weight decreased as the
temperature decreased and soil moisture stiess increased. The optimum tempera-
ture and soil moisture stress for total and earliness of emergence was 25 to
30 C and 1.18 atm. No emergence occurred at 10.84 atm of moisture stress and
total emergence was reduced only at 5.90 atm and 20 C.
72-73:02G-190
RELATIONSHIP BETWEEN SOIL OXYGEN DIFFUSION RATE AND YIELD OF OATS IN A COASTAL
ALLUVIAL SOIL AT CRITICAL SALINITY LEVEL,
Saini, G. R.
Research Station, Agriculture Canada, Fredericton, N. B., Canada.
Agronomy Journal, Vol. 65, No. 5, p 841-842, September-October, 1973. 1 fig,
1 tab, 7 ref.
Descriptors: *Salinity, *Oxygenation, Root distribution, Root zone, Root
development.
This note reports the effect of improved soil physical conditions, as character-
ized by oxygen diffusion rate (ODR), on the growth of oats at the critical soil
salinity level (ECe = 5.0 mmhos cm-1). In a coastal alluvial soil at critical
salinity level, the yield of oats increased from 0.55 g/pot to 10.88 g/pot as
ODR increased from 7.3 x 10 to the minus 8th power grams per cm squared per
minute to 31.0 x 10 to the minus 8th power grams per cm squared per minute.
The root elongation of the plant also appeared to be related to ODR.
72-73:026-191
SUGARBEET RESPONSE TO IRRIGATION AS MEASURED WITH GROWTH SENSORS,
Johnson, W. C., and Davis, R. G.
United States Department of Agriculture, Southwestern Great Plains Research
135
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Center, Bushland, Texas.
Agronomy Journal, Vol. 65, No. 5, p 789-794, September-October, 1973. 7 fig,
5 ref.
Descriptors: *Soil moisture, *Crop response, *Sugar beets, Irrigation,
Irrigation practices, Growth rates.
The continuous growth records of two typical irrigated sugarbeet roots were
compared at Bushland, Texas, during a 48-day period, June 25 to August 11,
1970, in a record dry season when there was little interference from rainfall
on the effect of irrigation on root growth. The roots received 10 cm of
irrigation water on staggered dates so that the growth record of a root not
being irrigated at a particular time might be used to interpret the growth
response to irrigation of the second root. The soil was slowly permeable,
requiring an average of about 3 days for free water to disappear after an
irrigation. A slow-growth period of about 3 days in length occurred after
each irrigation during which time the irrigated root grew more slowly than
the unirrigated root. When moisture stress was not extreme at the time of
irrigation, a temporary decrease in growth rate actually occurred after irri-
gation.
72-73:020-192
EFFECT OF NARROW TRENCHING IN HARLINGEN CLAY SOIL ON PLANT GROWTH ROOTING
DEPTH, AND SALINITY,
Heilman, M. D., and Gonzalez, C. L.
United States Department of Agriculture, Agricultural Research Service, Soil,
Water, and Air Sciences, Southern Region, Weslaco, Texas.
Agronomy Journal, Vol. 65, No. 5, p 816-819, September-October, 1973. 5 fig,
4 tab, 12 ref.
Descriptors: *Soil texture, *Salinity, Crop response, Cultivation, Cotton,
Root zone, Root distribution.
Narrow, backfilled trenches (61 and 102 cm deep) were tested in a Harlingen
clay soil as a management technique to increase rooting depth and volume of
soil available to roots. Cotton was planted directly over the trenches each
year for 3 years. Cotton yields were significantly increased by trenching
during 1971 and 1972. Yields of 815, 995, 1163, and 1018 kg/ha were obtained
during 1972 for check, 61-cm trench soil-backfilled, 61-cm trench, soil-
vermiculite backfilled, and 102-cm trench soil-backfilled, respectively. Root
penetration and distribution was increased from 60 cm for conventional tillage
to 122 cm for 102-cm deep trenches. An average of 8396 of roots for conventional
tillage were in surface 30 cm as compared with 43% of 102-cm trench. Trenching
increased water infiltration rates, decreased soil bulk density in trenches,
and increased soil root volume available to plants.
72-73:026-193
RAINOUT SHELTER AND DRAINAGE LYSIMETERS TO QUANTITATIVELY MEASURE DROUGHT
STRESS,
Teare, I. D., Schimmelpfennig, H., and Waldren, R. P.
Kansas State University, Evapotranspiration Laboratory, Manhattan.
Agronomy Journal, Vol. 65, No. 4, p 544-547, July-August, 1973. 7 fig, 2 ref.
Descriptors: *Lysimeters, *Drainage, Stress, Droughts, Drought tolerance.
136
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A modern rainout shelter designed to open and close with an improved electronic
control system and to withstand high winds is described. It was installed in
conjunction with drainage lysimeters to quantitatively evaluate evapotranspira-
tion, physiological indicators of drought stress, and irrigation scheduling.
72-73:020-194
A RESISTANCE MODEL TO PREDICT EVAPOTRANSPIRATION AND ITS APPLICATION TO A SUGAR
BEET FIELD,
Brown, K. W., and Rosenberg, N. J.
Texas A & M University, Soil and Crop Sciences Department, College Station.
Descriptors: *Evapotranspiration, *Measurement, *Sugar beets, Mathematical
models. Computer models, Soil moisture.
A method is needed to extrapolate the detailed micrometeorological and lysi-
metric determinations of evapotranspiration and its dependence on the micro-
climate and crop factors to fields where such detailed measurements are not
made. The dependence of latent heat flux from a crop on crop resistance, air
resistance, air temperature, water vapor pressure, and net radiation minus
soil heat flux was evaluated by means of an electrical resistance analogue
of the transfer process and by means of an energy balance equation. The
difficulties inherent in the application of the model to both the single leaf
and the crop are discussed. The major difficulty in applying the resistance
model to a field crop may be that the sinks and sources of latent and sensible
heat flux may not be identical within the crop. Hourly LE predicted by the
model and determined by the energy balance generally agreed within 5%. Daily
totals of LE, evaluated by the two methods, agreed well on all occasions.
72-73:020-195
SALT TOLERANCE OF CHICKPEA VARIETIES DURING GERMINATION,
Kheradnam, M., and Ghorashy, S. R.
Pahlavi University, Department of Agronomy, Shiraz, Iran.
Agronomy Journal, Vol. 65, No. 2, p 329, March-April, 1973. 1 fig, 8 ref.
Descriptors: *Salinity, *Crop response, Germination, Osmotic pressure, Crop
production, Yield equations.
Effects of seven salinity levels (0 to 2% NaCl) on germination of Iranian
chickpea varieties, 'Isfahan 11,' 'Ardebill 169,' 'Ardebill 174,' and 'Ahar
174' were determined under controlled temperature (30 + 2 C). Increased salin-
ity reduced the germination of Isfahan 11 significantly more than Ardebill
174 and Ahar 174. Sodium chloride concentrations greater than 0.5% reduced
the germination of all varieties significantly. Ghe general trend in germina-
tion reduction with increased salinity was the same for each variety.
72-73:020-196
RESPONSE OF THREE CORN HYBRIDS TO LOW LEVELS OF SOIL MOISTURE TENSION IN THE
PLOW LAYER,
Rhoads, F. M., and Stanley, R. L., Jr.
Agricultural Research and Education Center, Quincy, Florida.
Agronomy Journal, Vol. 65, No. 2, 315-318, March-April, 1973. 3 fig, 3 tab,
9 ref.
Descriptors: *Irrigation, *Irrigation practices, *Crop response, Tensiometers,
Soil moisture, Tension, Fertility.
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The objective was to evaluate the response of three corn hybrids to irrigation
treatments that were designed to maintain soil moisture tension at low levels
in the plow layer rather than the entire root zone. Flowering date, plant
height, and grain yield were used as indexes of response. Irrigation was
applied at four levels (0.3, 0.6, 2.0, and 5.0 bars) of soil moisture tension
in 1970 and at three levels in 1971. Nitrogen was applied at 336 and 560
kg/ha, in 1971, to treatments irrigated at 0.2 bar of soil moisture tension.
Each irrigation treatment was replicated four times and consisted of applying
water at a selected value of soil moisture tension. A tensiometer was placed
in each plot to be irrigated at soil moisture tensions below 1 bar in order to
monitor soil moisture tension at a depth of 15 cm. Electrical resistance
units were used in 1970 to monitor soil moisture tension in plots irrigated
at tensions above 1 bar.
72-73:020-197
WATER RELATIONS AND GROWTH OP COTTON IN DRYING SOIL,
Klepper, B., Taylor, H. M., Huck, M. G., and Fiscus, E. L.
Auburn University, Department of Botany and Microbiology, Alabama.
Agronomy Journal, Vol. 65, No. 2, p 307-310, March-April, 1973. 5 fig, 1 tab,
17 ref.
Descriptors: *lrrigation, *Soil moisture, *Crop response, Cotton, Transpira-
tion, Root development, Root systems, Diurnal.
Two 70-day-old cotton plants were subjected to a 26-day drying cycle at the
Auburn rhizotron in order to quantitatively study water relations and growth
of both root and shoot as the soil dried. Measurements were made of rooting
density changes; stem diameter and height increase; and soil water content,
soil water potential, and plant water potential. Marked diurnal fluctuations
in plant hydration and soil water potential were observed, especially during
the middle of the drying cycle. Plant height increase and stem diameter growth
slowed drastically after 17 days even though 35% of the root system was in
soil wetter than -1 bar and the plant was rehydrating to a water potential of
-3 to -5 bars. Plant water potential in the early morning did not equilibrate
with the water potential of the wettest horizon of soil.
72-73:020-198
EFFECT OF POROUS ROOTZONE MATERIALS UNDERLINED WITH PLASTIC ON THE GROWTH OF
CREEPING BENTGRASS,
Ralston,D. S., and Daniel, W. H.
Miller, Wihry and Brooks, Louisville, Kentucky.
Agronomy Journal, Vol. 65, No. 2, p 229-232, March-April, 1973. 5 fig, 2 tab,
7 ref.
Descriptors: *Soil moisture, *Crop response, *Graases, Perched water, Plastics,
Tension, Pore water,Porosity.
Creeping bentgrass was studied under putting green conditions when grown on
replicated plastic-lined plots containing dune sand, mortar sand, calcined
clay, diatomaceous earth, and peat. Soil was not included in any of the
rootzone mixtures because of its inherent structural instability. In 1968
and 1969, some infiltration rates exceeded 150 cm/hr and all were greater
than 7 cm/hr, therefore, water movement was considered ample. The relative
ability of the material in plots to retain moisture was measured by allowing
the plots to dry-down for 15 days between rains during August 1968 and for 17
138
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days during July 1969. No irrigation was added to any plot until turf showed
severe wilt. Bentgrass on plots containing the finer fractions of the dune
sand, diatomaceous earth, various mixtures of sand, calcined aggregates, and
peat did not require water for either period.
72-73:020-199
EFFECTS OF SUBSURFACE ASPHALT LAYERS ON CORN AND TOMATO ROOT SYSTEMS,
Saxena, G. K., Hammond, L. C., and Robertson, W. K.
Florida University, Soil Science Department, Gainesville.
Agronomy Journal, Vol. 65, No. 2, p 191-194, March-April, 1973. 3 fig, 2 tab,
13 ref.
Descriptors: *Root systems, *Root zone, *Asphalt, Barriers, Root distribution,
Corn, Tomatoes, Crop response.
This study was initiated to determine the nature and reason of any influence
of a subsurface asphalt layer on root growth and distribution in the soil
profile. Observations of root distributions of sweet corn and tomato were
made in freshly dug pits. Root sections in and out of the asphalt layer were
photographed and examined microscopically for morphological effects. The "line-
intercept" method was used to obtain quantitative measurements of root concentra-
tion of field corn. Tomato roots in the asphalt layer were larger in diameter
and showed damage to cells in the cortex. Rooting of all crops was less exten-
sive in soil below the asphalt layer than in soil at the same depth without
the asphalt. Concentration of corn roots in the top 60 cm of soil averaged
1.6, 1.7, 2.0, and 2.2 cm/cc for the following respective treatments: control,
control with irrigation, asphalt layer, and asphalt layer with irrigation.
72-73:02G-200
EFFECTIVENESS OF TWO NITRIFICATION INHIBITORS FOR ANHYDROUS AMMONIA UNDER
IRRIGATED AND DRYLAND CONDITIONS,
Cochran, V. L., Papendick, R. I., and Woody, W. M.
United States Department of Agriculture, Agricultural Research Service,
Western Region, Pullman, Washington.
Agronomy Journal, Vol. 65, No. 4, p 649-653, July-August, 1973. 5 fig, 15 ref.
Descriptors: *Nitrogen, *Nitrification, *Leaching, Ammonia, Nitrogen cycle,
Nitrogen fixation, Wheat.
Potassium azide and 2-chloro-6-(trichloromethyl) pyridine were evaluated as
nitrification inhibitors for anhydrous NH3 field applied on irrigated and
nonirrigated Ritzville silt loam and on nonirrigated Naff silt loam in eastern
Washington. Formulations of KN3, N-Serve in liquid NH3, or NH3 alone were
applied to fallow soil in midsummer at a rate of 90 kg N/ha. Irrigations were
15 cm of water sprinkler applied 1 day or 2 weeks after fertilizer application,
and 10 to 15 cm of water each time at 4, 8, and 13 weeks after NH3 application.
The NH3 retention zone was sampled for NH+4 and NO-3 periodically through
December for the Naff soil and through February for the Ritzville soil. Both
KH3 and N-Serve effectively inhibited nitrification of the applied NH3 on
nonirrigated Ritzville soil when temperature and soil moisture were favorable
for rapid nitrification. However, KN3 was completely ineffective following
irrigation or, for the Naff soil, after rainwater penetrated below the reten-
tion zone 2 weeks after N application.
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72-73:02G-201
EFFECT OF SOIL MOISTURE DURING EARLY STAGES OF DEVELOPMENT ON GROWTH AND YIELD
OF COTTON PLANTS,
Marani, A., and Levi, D.
Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, Israel.
Agronomy Journal, Vol. 65, No. 4, p 637-641, July-August, 1973. 7 fig, 2 tab,
11 fig.
Descriptors: *Irrigation, *Irrigation practices, *Cotton, Crop response.
Soil moisture, Crop production. Tension.
The effect of three irrigation treatments on the vegetative development of two
cultivars of upland cotton was studied in two experiments conducted under
different climatic conditions. The treatments differed until the middle of
flowering and were designated as L (no irrigation), M (regular), and H(early
and excessive irrigation). From mid-flowering onwards all plots were irrigated
regularly. In both experiments, treatment L resulted in a slower growth rate,
smaller plants, fewer nodes and fruiting branches, and smaller leaf area
index (LAI), and dry matter (DM) weight throughout the season. Small differ-
ences were found between the effects of treatments M and H. No excessive
vegetation development was observed in this study. The highest rates of DM
production were associated with LAI values between 2.0 and 3.0 A close relation-
ship was found between lint yield. Dm production and leaf area duration.
72-73:020-202
WATER STRESS RELATIONS OF THE POTATO PLANT UNDER FIELD CONDITIONS,
Epstein, E., and Grant, W. J.
United States Department of Agriculture, Agricultural Research Service, Orono,
Maine.
Agronomy Journal, Vol. 65, No. 3, p 400-404, May-June, 1973. 9 fig, 15 ref.
Descriptors: *Soil moisture, *Crop response, *Potatoes, Water requirements,
Water utilization. Stress.
Potatoes grown in northern Maine are often subjected to extensive periods of
drought. The objective of this study was to examine the physiological response
of potatoes to soil water stress. Relative water content, leaf diffusive
resistance, and tuber water potential of two potato varieties were measured
under irrigated and nonirrigated conditions. There were pronounced differences
in relative water content, leaf diffusive resistance, and tuber water potential
as a result of irrigation. Relative water content (RWC) of plant leaves corre-
lated well with soil water potential but poorly with leaf diffusive resistance.
The two potato varieties differed in RWC when soil water potential was high.
Tuber water potential correlated well with RWC and soil water potential. Simil-
arity between tuber water potential and the RWC data suggested that the potato
plant exhibits water stress when the soil water potential drops below -0.25 bar.
72-73:02G-203
WATER LOSS FROM AN IRRIGATED SORGHUM FIELD: II. EVAPOTRANSPIRATION AND ROOT
EXTRACTION,
Stone, L. R., Horton, M. L., and Olson, T. C.
South Dakota State University, Plant Science Department, Brookings.
Agronomy Journal, Vol. 65, No. 3, p 495-497, May-June, 1973. 5 fig, 9 ref.
Descriptors: *Drainage, *Evapotranspiration, *Deep percolation. Soil water,
140
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Soil moisture, Tensiometers, Soil water movement.
A method using tensiometers for obtaining evapotranspiration rates and root
extraction patterns within an actively growing sorghum crop is discussed.
Profile water depletion was calculated from water content profiles determined
using tensiometer readings and laboratory-measured soil water characteristics.
Profile water depletion minus flux below the root zone yielded the daily
evapotranspiration rate. During the 31-day study, approximately 65% of the
total water loss was due to flux loss from the root zone. These data clearly
show the importance of considering flux below the root zone when attempting
to determine evapotranspiration rates using depletion methods. The method of
determining evapotranspiration rates illustrated in this paper provides an
alternative to the microclimatolojical and lysimeter methods.
72-73:020-204
COTTON LEAF TEMPERATURES AS RELATED TO SOIL WATER DEPLETION AND METEOROLOGICAL
FACTORS,
Ehrler, W. L.
United States Water Conservation Laboratory, Phoenix, Arizona.
Agronomy Journal, Vol. 65, No. 3, p 404-409, May-June, 1973. 4 fig, 3 tab,
9 ref.
Descriptors: Irrigation, *Irrigation practices, *Crop response, Cotton, Soil
moisture, Tension.
In two field experiments with cotton, the relation between moderate soil water
depletion and leaf-air temperature difference (Delta T) was investigated for
feasibility of measurement and possible use as a guide to irrigation scheduling.
Hourly temperatures of the upper leaves and of the air 1 m above the canopy
were obtained for three cultivars of short-staple cotton and one of long-staple.
In addition, hourly measurements were made of the vapor pressure 1 m above the
crop. These data were taken during six irrigation cycles extending over two
summers and encompassing a wide range of saturation deficit (SD). The tempera-
ture differences were measurable and predictable. When the SD remained steady
from day to day, the mean daytime Delta T decreased 1 C on the day of irriga-
tion and an additional degree the next day owing to leaf rehydration and conse-
quent stomatal opening.
72-73:026-205
IONIC BALANCE FOR BARLEY AS INFLUENCED BY P FERTILITY, WATER, AND SOIL TEMPERA-
TURE,
Follett, R. F., and Reichman, G. A.
United States Department of Agriculture, Northern Great Plains Research Center,
Mandan, North Dakota.
Agronomy Journal, Vol. 65, No. 3, p 477-482, May-June, 1973. 4 fig, 1 tab,
23 ref.
Descriptors: **Nutrient removal, *Leaching, *Phosphorus, Barley, Ion transport,
Fertility, Fertilizers.
The relationship between organic anion concentration and yield of spring
barley was investigated in a growth room at three levels of P. This relation-
ship was tested at three levels of available soil water (W) and three soil
temperatures (T). The concentration of organic anions was determined as the
difference between the sum of the meq/kg of inorganic cations and the sum of
141
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the meq/kg of inorganic anions. A normal organic anion (C-A) concentration
was considered to be that giving optimal growth. In this study, P was more
important for obtaining a normal (C-A)than either W or T. Phosphorus increased
yields, decreased (C-A) to near normal, and decreased the adverse effects of
low W and low T. The large differences in (C-A) between treatments suggests
that, under adverse conditions, organic anions may serve as reservoirs of
useful metabolites.
72-73:026-206
WATER LOSS FROM AN IRRIGATED SORGHUM FIELD: I. WATER FLUX WITHIN AND BELOW
THE ROOT ZONE,
Stone, L. R., Horton, M. L., and Olson, T. C.
South Dakota State University, Plant Science Department, Brookings.
Agronomy Journal, Vol. 65, No. 3, p 492-495, May-June, 1973. 5 fig, 1 tab,
6 ref.
Descriptors: *Soil water, *Soil moisture, *Leaching, Tensiometers, Hydraulic
gradient, Hydraulic conductivity.
This work was done to evaluate water movement within and below the root zone
of a sorghum crop during a 31-day field study following water application.
Hydraulic potential data from tensiometers placed at eight depths in the soil
profile were used to determine the hydraulic gradients. Soil water flux in
various depth layers was calculated using the hydraulic potential gradients and
the determined hydraulic conductivity vs soil water content relationships.
Upward water movement commenced in the 15 to 30 cm layer 3 days following water
application and 130 to 150 cm layer after 19 days. The upward water flux into
the root zone reached a maximum of approximately 0.2 cm/day near the end of
the study period. During the 31-day study period, 6.0 cm of water were lost
from the 150 cm soil profile by flux below the root zone. This illustrates the
importance of considering water loss due to flux below the root zone in crop
situations.
72-73:020-207
YIELD RESPONSE OF SOYBEAN VARIETIES GROWN AT TWO SOIL MOISTURE STRESS LEVELS,
Mederski, H. J., and Jeffers, D. L.
Ohio Agricultural Research and Development Center, Wooster.
Agronomy Journal, Vol. 65, No. 3, p 410-412, May-June, 1973. 2 tab, 12 ref.
Descriptors: *Irrigation, *Irrigation practices, Soil moisture, Crop response,
Soybeans, Stress, Droughts.
Eight soybean varieties in each of four maturity groups were grown to maturity
at optimum and deficient soil moisture conditions to determine differences in
varietal response to soil stress. A significant variety by stress level inter-
action on seed yield was detected among varieties in each of four maturity
groups, indicating that the effect of soil moisture stress on yield varied
among varieties. Under high moisture stress conditions, the yield of the most
stress resistant varieties was reduced about 20%, while the yield of the least
stress-resistant varieties was reduced about 40%. Under conditions of optimum
soil moisture, the difference in yield among varieties was large relative to the
difference in yield produced under dificient moisture conditions. A low or
nonstress soil moisture level permits greater genotypic expression, thereby
increasing genotypic variance among varieties. A low soil moisture stress
environment appears to be the optimum environment for selecting soybean yield
attributes.
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72-73:02G-208
EFFECT OF SUPPLEMENTAL WATER ON BARLEY AND CORN PRODUCTION IN A SUBHUMID REGION,
Power, J. F., Bond, J. J., Sellner, W. A., and Olson, H. M.
United States Department of Agriculture, Northern Great Plains Research Center,
Mandan, North Dakota.
Agronomy Journal, Vol. 65, No. 3, p 464-467, May-June, 1973. 1 fig, 4 tab, 6
ref.
Descriptors: *Irrigation, *Irrigation practices, *Supplemental irrigation,
Irrigation programs, Irrigation effects, Corn, Barley.
A 3-year field experiment was conducted on a loam soil in eastern North Dakota
to determine the effect of supplemental water, added in various quantities and
at different times, on malting barley and corn silage production. Irrigation
consisted of (a) none; (b) after previous harvest only (to fill 120-cm profile);
(c) 6 cm applied per irrigation as needed during growing season; (d) after
previous harvest plus 6 cm at anthesis; (e) after previous harvest plus 6
cm applied as needed during the growing season; and (f) after previous harvest
plus 9 to 12 cm applied as needed during the growing season. Water added
after harvest was not reflected in soil water content by seeding time the
following spring or in increased crop yields, indicating that fall irrigation
was of little value. A linear regression existed between total water use and
both barley grain and corn silage production, with no distinct differences
between the six water treatments evident.
72-73:026-209
NITROGEN METABOLISM OF STARGRASS AS AFFECTED BY NITROGEN AND SOIL SALINITY,
Langdale, G. W., Thomas, J. R., and Littleton, T. G.
United States Department of Agriculture, Watkinsville, Georgia.
Agronomy Journal, Vol. 65, No. 3, p 468-470, May-June, 1973. 3 fig, 2 tab,
19 ref.
Descriptors: *Fertility, *Nitrogen, Fertilizers, Salinity, Nutrient removal.
Leaching, Crop response.
Interactive effects of soil salinity and N fertilizer on stargrass growth and N
metabolism were investigated. Nitrogen contents were partitioned to study the
effects of substrate salinities on hydrolysis of protein-N and the accumulation
nonprotein-N assimilates. Mixed chloride-sulfate solutions of the same ionic
ratios and electrical conductivities (EC) of 4.8, 9.6, and 14.4 mmhos/cm were
equilibrated with Brennan fine sandy loam soil, after which N was applied in a
factorial arrangement at rates of 0, 67, 133, and 200 mg/kg of soil. Nitrogen
fertilizer interacted significantly with soil salinity to stimulate dry matter
and protein-N yields at the 4.8-mmhos/cm level. No evidence of a toxic non-
protein-N accumulation in plant tissue was observed even with high N fertiliza-
tion at this salinity level. The 9.6-mmhos/cm salinity treatment was consider-
ably more deleterious to dry matter than to protein-N production processes.
72-73:020-210
INFILTRATION AND ROOT EXTRACTION FROM SUBSURFACE IRRIGATION LATERALS,
Gilley, J. R., and Allred, E. R.
Minnesota University, Agricultural Engineering Department, Saint Paul.
Presented at Winter Meetings of the American Society of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois. 27 p, 11 fig, 4 tab, 29 ref.
143
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Descriptors: *Irrigation, *Subsurface irrigation. Irrigation practices, Soil
moisture, Soil water movement. Soil physics.
An analytical solution to the soil moisture flow equation was used to simulate
flow in partially saturated soils during steady infiltration from buried line
sources. A series of plane sinks was used to model water consumption by
plants. The resulting model was used to determine optimum lateral placement to
obtain desired crop extraction patterns.
72-73:02G-211
A COMPUTER MODEL FOR PREDICTING NITRATE AND OTHER SOLUTES OP AGRICULTURAL
DRAIN WATER,
Dutt, G. R., and Saffer, M. J.
Arizona University, Department of Soils, Tucson.
Final report on Contract No. 14-06-D-7328, United States Bureau of Reclamation,
Denver, Colorado, June, 1972. 29 p, 4 fig, 2 append.
Descriptors: *Drainage, *Soils, Reclamation, Water quality. Pollutants,
Systems analysis. Computer models.
A computer simulation model was developed for predicting the changes in solute
composition due to chemical reactions in the saturated region below the water
table for tile drain systems underlaid by an impermeable layer. The ionic
species considered to be present in the water include Ca++, Mg++, Na+, NH4+,
SO4=, CI-, HCO3-, CO3=, and NO3-. chemical reactions considered are base
exchange, dissociation or precipitation of gypsum and lime (CaCO3), and reac-
tions between Ca and Mg of sulfate ion pairs in solution. Verification of the
model is considered. A procedure for utilizing the above with other models
previously developed by the authors and others is outlined. It is concluded
that the procedure developed is suitable for practical application to base
saturated soils fitting the boundary conditions. The procedure can be expanded
to consider other soils and interactions which may be found to be of importance
at a later date.
72-73:02G-212
DRAINAGE OBSERVATIONS IN LATIN AMERICA,
Christiansen, J. E.
Utah State University, Agricultural and Irrigation Engineering Department,
Logan.
Presented at Winter Meetings of the American Society, of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois. 4 p.
Descriptors: ^Drainage, ^Surface drainage, ^Subsurface drainage, Tile drainage,
Salinity, Water table. Soil water movement. Saline soils.
Although there are many excellent irrigation systems in most of the Latin
American countries, the problem of drainage and salinity generally has been
neglected. There are many areas where, because of lack of adequate natural
drainage, high water tables and acute salinity conditions have developed.
72-73:020-213
SIMULATION MODEL FOR EVALUATING IRRIGATION MANAGEMENT PRACTICES,
Morey, R. V., and Gilley, J. R.
Minnesota University, Agricultural Engineering Department, Saint Paul.
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Presented at Winter Meetings of the American Society of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois, 14 p, 8 fig, 1 tab, 16 ref.
Descriptors: *Irrigation practices, *Computer models, Mathematical models,
Irrigation, Irrigation systems, Irrigation effects, Soil moisture, Crop
response.
Identifiers: Irrigation Management.
A soil moisture budget which can be used to evaluate irrigation management
practices is presented. Results of a calibration-verification procedure are
included. The model is used to test several irrigation management policies for
two soil types and 24-years of weather data for St. Cloud, Minnesota.
72-73:026-214
DRAINAGE INVESTIGATIONS AND FINDINGS ON THE GOTVAND PROJECT - IRAN,
Jacobsen, P.
Harza Engineering Company, Chicago, Illinois.
Presented at Winter Meetings of the American Society of Agricultural Engineers,
December 11-15, 1972. Chicago, Illinois. 7 p, 3 fig, 2 tab, 3 ref.
Descriptors: *Drainage, *Surface drainage, *Subsurface drainage. Tile drainage,
Soil water, Salinity, Water table.
In the spring of 1972 a special drainage investigation, which included soil
analyses and permeability studies, was made on the Gotvand Project in Iran. As
a result, drainage recommendations were made for specific areas and a monitor-
ing system was proposed that wcuH indicate the need for additional drainage
before land damage can occur.
72-73:020-215
DRAINAGE AND WATER MANAGEMENT IN HUNGARY,
Donnan, W. W., and Jaranyi, G.
United States Department of Agriculture, Agricultural Research Service,
Riverside, California.
Presented at Winter Meetings of the American Society of Agricultural Engineers,
December 11-15, 1972. Chicao, Illinois. 9 p, 5 ref.
Descriptors: *Drainage, *Water management (applied), Surface drainage, Sub-
surface drainage, Tile drainage, Irrigation practices, Irrigation systems.
Hungary has enbarked on an ambitious program to develop its soil and water
resources. This paper details some of the progresses to date with emphasis
on the work in the drainage field.
72-73:020-216
COMPARISON OF DRAINAGE METHODS IN A HEAVY-TEXTURED SOIL,
Schwab, G. O., Fausey, N. R., and Michener, D. W.
Ohio Agricultural Research and Development Center.
Presented at Winter Meeting of the American Society of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois. 5 p, 1 tab, 6 ref.
Descriptors: *Drainage, Surface drainage. Subsurface drainage, Tile drainage,
Crop response, Soil water. Drainage engineering. Soil water movement.
145
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Corn, Oat, and soybean yields from surface drained, tile drained, and a combina-
tion of tiled and surface drained plots in northern Ohio were obtained over a
10-year period. Both conventional tillage and no tillage practices were
included. Rainfall plus irrigation and drainage flow effects on yields were
studied.
72-73:026-217
LAND DRAINAGE OF REDDISH CLAY LOAMS,
Massie, L. R., and Tenpas, G. H.
Wisconsin University, Madison.
Presented at Winter Meeting of the American Society of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois. 8 p, 1 fig, 5 tab.
Descriptors: *Drainage, Surface drainage, Subsurface drainage, Tile drainage,
Crop response, Soil water. Drainage engineering. Soil water movement.
An excellent forage can be established and maintained by providing a drainage
system (surface and/or tile), fertility, and selecting varieties carefully.
72-73:026-218
DEVELOPMENT OF BI-LEVEL DRAINAGE THEORY,
DeBoer, D. W., and Chu, S. T.
South Dakota State University, Brcokings.
Presented at Winter Meeting of the American Society of Agricultural Engineers,
December 11-15, Chicago, Illinois. 12 p, 4 fig, 6 ref.
Descriptors: ^Drainage, Surface drainage, Subsurface drainage, Tile drainage.
Crop response. Soil water, Drainage engineering. Soil water movement.
Two analytical solutions were derived for the bi-level drainage problem. The
two solutions, based on the Dupuit-Forchheimer assumptions, are for the
steady state and falling water table conditions. These solutions should be
applicable to the design of subsurface drainage systems with drain lines at
two elevations on an alternating basis.
72-73:026-219
EFFECT OF SURFACE DRAINA6E ON WATER TABLE RESPONSE TO RAINFALL,
Skaggs, R. W.
North Carolina State University, Department of Biological and Agricultural
Engineering, Raleigh.
Presented at Winter Meeting of the American Society of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois. 23p, 10 fig, 4 tab, 15 ref.
Descriptors: ^Drainage, ^Surface drainage. Crop response. Soil water, Water
table, Rainfall, Soil water movement, Drainage engineering.
A method for determining the effect of surface drainage on the water table
response to rainfall is presented and used to predict water table rise on a
Lumbee sandy loam. Predicted results were in good agreement with actual
measurements. Approximate methods for implementing the method are presented
and discussed.
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72-73:020-220
QUALITY OF DRAINAGE WATER FROM A HEAVY-TEXTURED SOIL,
Schwab, G. O., McLean, E. O., Waldron, A. C., White, R. K., and Michener, D. W.
Ohio State University, Department of Agricultural Engineering, Columbus.
Presented at Winter Meetings of the American Society of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois. 13 p, 2 fig, 4 tab, 11 ref.
Descriptors: ^Drainage, ^Subsurface drainage, Tile drainage. Water quality,
Salinity, Water chemistry, Ion transport.
Sediment, dissolved solids, nine chemical elements or ions, five pesticides,
electrical conductivity, pH, and BOD in tile effluent and in surface runoff
were measured from field plots in Toledo silty clay soil near Sandusky, Ohio,
for the period 1969-71. Measurements were taken from both conventional tilled
and no tilled plots in continuous corn. Laboratory studies were also made on
phosphorus movement.
72-73:020-221
SUBSURFACE IRRIGATION IN HAWAIIAN SUGARCANE,
Vaziri, C. M.
Hawaiian Sugar Planters' Association Experiment Station, Honolulu, Hawaii.
Presented at Winter Meeting of the American Society of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois. 11 p, 6 fig, 5 tab.
Descriptors: *Irrigation, *Subsurface irrigation, Irrigation practices,
Sugarcane, Hawaii, Irrigation engineering.
The first successful subsurface irrigation system for sugarcane was installed
on March 29, 1970, at HSPA Kunia Substation in an 8,000 square foot area.
The field was harvested on November 3, 1971. After harvest, the system was
inspected and found to be functioning adequately. Field results indicate
water savings and yield increase.
72-73:020-222
DYNAMIC SIMULATION OF AUTOMATED SUBSURFACE IRRIGATION SYSTEMS,
van Bavel, C. H. M., Ahmed, J., Bhuiyan, S. I., Hiler, E. A., and Smajstria, A.
G.
Texas A & M University, Soil and Crop Sciences Department, College Station.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 6,
p 1095-1099, November-December, 1973. 6 fig, 1 tab, 6 ref.
Descriptors: Irrigation practices, *Subsurface irrigation, Automation,
Computer models, Mathematical models, Soil moisture, Soil water, Soil water
movement.
Hater delivery and distribution from a subsurface irrigation system were
simulated for a simplified one-dimensional case. Water loss by surface evapo-
ration and root uptake was taken into account in a manner reflecting its
dependence upon depth and time of day. The system was defined as an automatic
one, in which the water content at a given depth would turn infiltration from
the buried delivery system off and on. The simulation was performed in S/360
CSMP, a dynamic simulation language that appears well adapted for this type
of problem. The program is efficient and allows ready substitution of the
hydraulic characteristics of the soil, the consumptive use pattern, and the
root uptake distribution with depth, as well as geometrical variables. The
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results suggest that in a Yolo clay loam and with a typical consumptive use and
root distribution pattern, an automated system will cycle from a delivery
period of about 2 hours through a redistribution period of about 40 hours,
while maintaining an essentially constant water content in the root zone,
provided the depth of delivery and control are properly chosen.
72-73:020-223
INFILTRATION AND WATER TABLE EFFECTS OF SOIL AIR PRESSURE UNDER BORDER IRRIGA-
TION,
Linden, D. R., and Dixon, R. M.
United States Department of Agriculture, Agricultural Research Service, Reno,
Nevada.
Soil Science Society of America Proceedings, Vol. 37, No. 1, p 94-98, January-
February, 1973. 7 fig, 11 ref.
Descriptors: *Irrigation, *Infiltration, Infiltration rates. Surface irriga-
tion, Border irrigation. Soil moisture.
Field studies investigated infiltration and water table responses to soil
air pressure under border irrigation. The water table was depressed in the
center and elevated near the edge of a border strip in response to differences
in soil air pressure during an irrigation. Also, water table elevations
indicated that infiltration and subsequent groundwater recharge rates were
greater in the vicinity of a border dike than at the center of the border. An
infiltration response was measured by: (i) venting soil air during an actual
irrigation and (ii) pumping air into the soil during simulated irrigations.
An actual border irrigation experiment indicated that displaced soil air
pressure ha rising to values of 13 to 24 cm of H2) reduced infiltration over
a 70-minute period from 14.3 to 10.3 cm. Simulated border irrigation experi-
ments indicated that displaced soil air pressure ha must exceed surface head
hs to have significant influence on infiltration and that the first few minutes
of infiltration may determine the ha-to-hs relationship and subsequent infil-
tration effects.
72-73:020-224
EFFECT OF IRRIGATION FREQUENCY ON THE AVERAGE EVAPOTRANSPIRATION FOR VARIOUS
CROP-CLIMATE-SOIL SYSTEMS,
Norero, A. L., Keller, J., and Ashcroft, G. L.
Universidad Catolica, Santiago, Chile.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 4,
p 662-666, July-August, 1972. 6 fig, 1 tab, 23 ref.
Descriptors: *Irrigation, *Irrigation practices, *Irrigation engineering,
Evapotranspiration, Water utilization.
The general relationship between ETRa and the time since the root zone soil
moisture has been completely replenished was developed and discussed. Examples
were given and the final development of ETRa versus t curves were produced
from field crop data found in the literature. The data selected were for
corn grown in shallow field lysimeters and deep rooted field alfalfa to demon-
strate rather extreme cases in terms of the irrigation frequency required to
maintain a high ETRa or relative productivity.
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72-73:02G-225
EFFECT OF ION-PAIR FORMATION ON THE SOLUBILITY PRODUCT.
Babcock, K. L., and Marion, 6. M.
California University, Department of Soils and Plant Nutrition, Berkeley.
Soil Science Society of America Proceedings, Vol. 36, No. 4, p 689-691,
July-August, 1972. 4 ref.
Descriptors: *Ions, Ion exchange, Solubility, Gypsum, Soil chemistry.
Two treatments of electrolyte solutions in which ion-pair formation occurs
are possible: one as a strong electrolyte, the other as a weak electrolyte.
It is demonstrated, however, that the value of a solubility product is inde-
pendent of the method of treatment.
72-73:02G-226
RESIDUAL EFFECTS OF N15-LABELED FERTILIZERS IN A FIELD STUDY,
Westerman, R. L., and Kurtz, L. T.
Illinois University, Department of Agronomy, Urbana.
Soil Science Society of America Proceedings, Vol. 36, No. 1, p 91-94, January-
February, 1972. 1 fig, 3 tab, 6 ref.
Descriptors: *Nutrient removal, *Nitrogen, *Leaching, Crop production, Crop
response, Crops, Denitrification, Radioisotopes.
Residual effects of two Nl5-labeled N fertilizers, urea and oxamide, were
compared during the second cropping season after they had been applied at rates
of 0, 56, 112, and 168 kg N/ha. 'Sudax SX111 sorghum-sudan grass hybrid was
grown and harvested three times during this second cropping season while the
residual effects were being measured. Fertilizer N removed in plant tops
during this second year of cropping contained 13-18% of the residual fertilizer
N in the soil at the end of the first season and was equal to 4-6% of that
applied originally in the fertilizers. At the end of the second cropping
season, 22 and 26% of the initial applications of N in urea and oxamide,
respectively, remained in the soil. The effect of carriers on these amounts
of residual fertilizer N was not significant. The removals in crops during
the second season were essentially equal to the residual fertilizer N which
had been in the soil at the end of the first season.
72-73:020-227
SOIL MULCH EFFECTS ON SEEDBED TEMPERATURE AND WATER DURING FALLOW IN EASTERN
WASHINGTON,
Papendick, R. I., Lindstrom, M. J., and Cochran, V. L.
United States Department of Agriculture, Agricultural Research Service, Pullman,
Washington.
Soil Science Society of America Proceedings, Vol. 37, No. 2/ p 307-314, March-
April, 1973. 8 fig, 1 tab, 23 ref.
Descriptors: *Mulching, *Dry farming. Wheat, Temperature, Thermal insulation,
Cultivation, Unsaturated flow. Evaporation.
Depth of dry soil mulch affected summer soil temperatures and seed-bed water at
the end of fallow in the dryland wheat region of eastern Washington. Increasing
the depth of the tillage mulch from 6 to 11 cm reduced summertime seed zone
drying sufficiently to benefit wheat emergence. Reduction of drying was
greatest when the seed zone had good capillary continuity with the deeper soil
149
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layers. Drying depth and intensity was greater with a cloddy soil mulch than
with a fine mulch. The seed zone water-conserving effect of a fine soil
mulch was related to the lowered temperatures and temperature gradients across
the seed zone associated with the increased mulch depth. The deeper soil
mulch conserved seedbed water through increased resistance to water flow from
moist layers to the atmosphere, and through increased thermal insulation of
the moist soil below the dry mulch. Surface-applied straw decreased seed-
zone temperatures under the shallow mulch only.
72-73:020-228
RESPONSE OF CORN TO TIME AND RATE OF PHOSPHORUS AND ZINC APPLICATION,
Keefer, R. F., Singh, R. N., Horvath, D. J., and Henderlong, P. R.
West Virginia University, Plant Sciences Division, Morgantown.
Soil Science Society of America Proceedings, Vol. 36, No. 4, p 628-632, July-
August, 1972. 5 fig, 8 tab, 23 ref.
Descriptors: *Nutrients, *Corn, *Crop response, Phosphorus, Zinc, Soil chem-
istry. Fertility, Fertilization.
Corn was grown in the greenhouse on two soils - Monogahela, a Typic Fragiudult
(I) and Wharton, an Aquic Hapludult (II), which differed in available Zn,
available P, exchangeable Mg, total Zn, and organic matter (OM). Dry matter
yield and Zn concentration and content of plant parts were increased where Zn
either as ZnSO4 or ZnEDTA was applied with P regardless of time to soil I.
Zinc-EDTA seemed to be a better source of Zn since it increased Zn concentra-
tion in leaves and stems more than ZnSO4 on soil I. However, with soil II,
response to ZnSO4 application was obtained only when P was applied at high
rates 8 weeks before planting. Application of ZnEDTA produced no significant
response by corn on soil II, probably due to instability of ZnEDTA under acid
conditions resulting in appreciable amounts being fixed on clays in this
soil. The relative response to Zn with increasing levels of P was greater on
soil I than on soil II. Addition of Zn in the former decreased the percent P
and P content in both leaves and stems at high levels of P application;
however, application of Zn to all the latter did not show any noticeable
affect on percent P at all levels of P application.
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Section VIII
WATER CYCLE
LAKES (Group 02H)
72-73:02H-001
NITROGEN TRANSFORMATIONS IN SEDIMENTS AS AFFECTED BY CHEMICAL AMENDMENTS,
Chen, R.L., and Keeney, D.R. '
Wisconsin University, Department of Soil Science, Madison.
Water Resources Bulletin, Vol 9, No 6, p 1136-1144, December 1973. 8 tab,
27 ref.
Descriptors: *Sediments, *Nitrogen cycle, Marl, Line, Nitrification,
Denitrification, Nitrogen fixation, Methane, Methane bacteria.
Identifiers: Acid sediments, Aluminum sulfate.
A study was conducted to elucidate some of the chemical factors affecting
the rate and pathways of N transformations in lake sediments. Emphasis
placed on modifying a noncalcareous sediment with CaCO, to approximate
the composition of a calcareous sediment. The effects of Ca**, CO 2-,
Mg2+ and OH- were evaluated by using appropriate chemicals. The effect of
aluminum sulfate was evaluated with both sediment types. Sediment pH at
7 days was not affected by CaCO.., but was decreased by aluminum sulfate. The
CaCO- treatment increased the rate of ammonification, nitrification,
reduction of acetylene to ethylene and methane formation, while with few
exceptions the other treatments decreased the rate of the transformations
studied. Aluminum sulfate, which has been proposed as a lake restoration
treatment, increased ammonification but decreased most of the other trans-
formations .
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Section IX
WATER CYCLE
WATER IN PLANTS (Group 021)
72-73:021-001
WATER-YIELD RELATIONS FOR NONFORAGE CROPS,
Downey, L. A.
New South Wales Department of Agriculture, Leeton, Australia.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IRl, p 107-115, March, 1972. 3 fig, 13 ref.
(See 72-73:020-047)
72-73:021-002
A SYSTEMATIC APPROACH TO SIMULATING CORN PRODUCTION SYSTEMS,
Holtman, J. B., Pickett, L. K., Armstrong, D. L., and Connor, L. J.
Michigan State University, Agricultural Engineering Department, East Lansing.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 1,
p 19-23, January-February, 1973. 10 fig, 3 tab, 18 ref.
Descriptors: *Computer models, *Crop production, Simulation analysis, Crop
response, Yield equations, Corn.
A study of the role of the producer as decision-maker revealed that certain
informational tools were required for fruitful decisions. Three types of
information identified as important for the producer's needs were: (a) long
run system performance data for determining average expected return, (b) short
run system performance data for immediate tactical decisions and (c) risk
associated with various alternatives available for the decision. Simulation
was found to be a suitable approach for obtaining the information required for
the necessary decisions. A flexible approach to simulation model construction
was selected as the best way to meet the differing needs of producers and the
needs of researchers and extension specialists involved in improving decision-
making techniques. Flexibility of application was obtained by systematic
construction of component models which can be used in combinations appropriate
to the decision problem. Simulation of the harvesting phase of a 200 acre
corn farm was provided as one example of combining component models to provide
information contributing to a particular decision.
72-73:021-003
WATER RELATIONS OF WHEAT AS AFFECTED BY IRRIGATION AND NITROGEN FERTILIZATION,
Dougherty, C. T.
Lincoln College, Department of Plant Science, Canterbury, New Zealand.
New Zealand Journal of Agricultural Research, Vol. 16, No. 1, p 12-18, February,
1973. 6 tab, 24 ref.
Descriptors: *Soil moisture, *Crop response, *Wheat, Nitrogen, Fertilization,
Fertility, Crop production. Soil-water-plant relationships.
Water potentials of flag leaves and ears on the same tiller of Kopara wheat
were measured soon after ear emergence by a pressure-bomb technique. Water
potentials of ears were nearly 0.5 bar higher than those of flag leaves. At
soil water levels of 20%, water potentials of -8 to -9 bars were recorded at
0900 hour on a day of high solar radiation with relatively little advective
heat transfer. In non-irrigated wheat, soil water levels were well below the
152
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permanent wilting point, and the water potentials of the ears were lower than
-20 bars. Nitrogen fertilizer had no direct effect on ear water potential,
but in non-irrigated wheat it depleted soil water, probably by increasing leaf
area index and transpiration. As a result soil water levels in non-fertilized,
non-irrigated plots were well above the wilting point, and the water potentials
of the ear of wheat growing in them were similar to those which were irrigated.
72-73:021-004
COMPUTER SIMULATION OF CROP PRODUCTION - POTENTIAL AND HAZARDS,
Bowen, H. D., Colwick, R. F., and Batchelder, D. G.
North Carolina State University, Agricultural Engineering Department, Raleigh.
Agricultural Engineering, Vol. 54, No. 10, p 42-45, October, 1973. 2 fig,
20 ref.
Descriptors: *Computer models, *Plant growth. Cotton, Yield equations. Crop
production. Plant populations.
A summary of the work completed by various investigators in the field of
computer simulation are reviewed. The purpose and progress of Project S-69
is presented. This work consists of a committee from cotton producing states
in the Southwest, studying the computer simulation of the growth of cotton
plants. Hazards inherent to this type of work are discussed.
72-73:021-005
SENSITIVITY OF SOUTHERN PEAS TO PLANT WATER DEFICIT AT THREE GROWTH STAGES,
Hiler, E. A., van Bavel, C. H. M., Hossain, M. M., and Jordan, W. R.
Texas A & M University, Department of Agricultural Engineering, College Station.
Agronomy Journal, Vol. 64, No. 1, p 60-64, January-February, 1972. 8 fig,
2 tab, 12 ref.
Descriptors: *Moisture stress, *Peas, *Soil moisture. Water utilization.
Efficiencies, Leaves.
Response of southern peas to different levels of water deficit at three differ-
ent stages of growth was measured in a greenhouse. In each stage, plants were
stressed to three levels of leaf water potential: -14 bars, -21 bars, and -28
bars. Crop susceptibility factors were determined for each stage of growth
and level of plant water deficit. The flowering period was found to be the
most sensitive stage, regardless of deficit level. The pod development stage
was found to be least sensitive to level of deficit. A water deficit of -28
bars, however, caused a yield reduction of greater than 50% for all growth
stages. Stress-day index values were calculated and related to crop yield.
The use of the stress-day index concept in irrigation scheduling is discussed.
72-73:021-006
DETERMINATION OF TOTAL NITROGEN IN PLANT MATERIAL,
Nelson, D. W., and Sommers, L. E.
Purdue University, Agronomy Department, Lafayette, Indiana.
Agronomy Journal, Vol. 65, No. 1, p 109-112, January-February, 1973. 6 tab,
21 ref.
Descriptors: *Nitrogen, Nitrates, Digestion, Fertility, Crop response.
153
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A simple and precise procedure for estimating total N in plant tissue is
described; a modification is also described for analysis of samples containing
high nitrate concentrations. Plant tissue samples are placed in pyrex Folin-
Wu tubes and digested with a salt-catalyst-sulfuric acid mixture by heating
the tubes in an aluminum block. Samples are digested at the boiling point
of the mixture for 60 min. after initial clearing of the digests. Analyses
of diverse plant materials, containing from 0.006 to 0.3% Nitrate-N, indicated
that the proposed and standard AOAC procedures yielded essentially the same
total N values. The coefficient of variation for the proposed methods varied
from 0.87 to 1.10%. The tube digestion procedures described allows digestion
of 60 plant samples simultaneously and thus greatly improve the efficiency
of total N determinations.
72-73:021-007
A MODEL FOR ESTIMATING DESIRED LEVELS OP NITRATE-N CONCENTRATION IN COTTON
PETIOLES,
Grimes, D. W., Dickens, W. L., Yamada, H., and Miller, R. J.
California University, Department of Water Science and Engineering, Davis.
Agronomy Journal, Vol. 65, No. 1, p 37-41, January-February, 1973. 5 fig,
3 tab, 14 ref.
Descriptors: *Nitrogen, *Fertilizers, *Cotton, Crop response, Water management
(applied), Water pollution sources.
Field studies were conducted on two widely different soils over a three-year
period in a semiarid irrigated region to establish functional relations between
responses of cotton plants and the major production input factors: water,
nitrogen, and plant density. The nitrate-nitrogen concentrations of petioles
from the most recently matured leaves were influenced by N-fertilization level,
time of sampling in the season, and water management. Plant population did not
alter the nitrate-N levels of petioles. High concentrations were associated
with large amounts of N applied in side-dress soil applications. On a fine-
textured soil with a high water-retention capacity N side-dressed after emer-
gence was not taken up by the plant until the first irrigation was added. Con-
centrations of nitrate-N in petioles at critical times in the season were
characterized by a 2nd-degree polynomial model having water and nitrogen
quantities as independent variables.
72-73:021-008
INTERNAL LEAF WATER STATUS AND TRANSPORT OF WATER IN RICE PLANTS,
Tomar, V. S., and Ghildyal, B. P.
G. B. Pant University of Agriculture and Technology, Department of Soil
Science, Pantnagar, Nainital, India.
Agronomy Journal, Vol. 65, No. 6, p 861-865, November-December, 1973. 8 fig,
26 ref.
Descriptors: *Rice, *Water utilization, *Transpiration, Water transfer. Leaves,
Crop response, Crop production.
The objective of this study was to relate transpiration rate and leaf water
potential to relative water content. This information may be useful in pre-
dicting the effect of soil moisture stress on growth and yield. Rice variety
'IR-8' was grown in the greenhouse for 50 to 60 days under submergence and
-1/3 bar soil matric potential, and then allowed to wilt. The pressure poten-
tial of leaves approached zero at a total water potential of about -19.5 bars,
154
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corresponding to 0.33 relative water content. Leaves experienced a change in
cell elasticity at about 3 bars pressure potential and -10 bars total water
potential. Transpiration rate decreased with leaf water potential, but it
was independent of depletion of soil moisture content above 0.21 and 0.18 for
plants grown in submerged and unsaturated soil conditions, respectively.
These moisture contents correspond to -0.8 bar and -2.0 bars matric potential.
72-73:021-009
ROOTING DENSITY AND WATER EXTRACTION PATTERNS FOR CORN,
Taylor, H. M., and Klepper, B.
United States Department of Agriculture, Agricultural Research Service, Ames,
Iowa.
Agronomy Journal, Vol. 65, No. 6, p 965-968, November-December, 1973. 3 fig,
4 tab, 12 ref.
Descriptors: *Hydraulic conductivity, Water utilization, Plant growth, Consump-
tive use. Root distribution, Root systems, Corn.
An experiment was conducted to compare water-absorbing efficiency, per centi-
meter of root, of corn roots deep in the profile with that of roots near the
soil surface. Plants were grown in a rhizotron compartment with rainfall
excluded by a metal cover over the soil. Soil water content was determined
with a neutron probe; rooting density, from measurements of roots on the glass
viewing surface of the compartment. Leaf area was calculated by a length-
width method and plant height was measured daily. For the first weeks, trans-
piration exceeded pan evaporation, but toward the end of the experiment it was
about half as much as pan evaporation. Water uptake per centimeter of root
was affected most by soil hydraulic conductivity, and at a given conductivity,
it was greater at lower root densities. For the conditions of these experi-
ments, roots deep in the profile were probably more effective per centimeter
of root for water uptake than shallow roots because they were younger and
were in wetter soil.
72-73:021-010
EFFECT OF ESTABLISHMENT METHOD, VARIETY, AND SEEDING RATE ON THE PRODUCTION
AND QUALITY OF ALFALFA UNDER DRYLAND AND IRRIGATION,
Eansen, L. H., and Krueger, C. R.
South Dakota State University, Plant Science Department, Brookings, South
Dakota.
Agronomy Journal, Vol. 65, No. 5, p 755-759, September-October, 1973. 1 fig,
3 tab, 10 ref.
Descriptors: *Alfalfa, Planting management, Crop response, Management.
This study was designed to compare alternative establishment methods and deter-
mine the influence of alfalfa varieties and seeding rates on dry matter and
crude protein production and herbage quality. The relationship between alfalfa
plant density and root+crown weight and their effect on forage yield were
evaluated. Pure stands of alfalfa were established by four methods: (1) no
herbicide or companion crop (check); (2) a pre-plant herbicide, S-ethyl dipropyl-
thiocarbamate (EPTC); (3) a companion crop of oats harvested for grain.
Three alfalfa varieties were evaluated: T3X-8 hybrid, 'Saranac,1 and 'Vernal.'
Four alfalfa seeding rates were compared: 4.5, 9.0, 13.5, and 17.9 kg/ha of
pure-live-seed. Studies were conducted at three locations in South Dakota.
Experiments at Gayville and Norbeck were under dryland conditions and at
155
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Brookings under irrigation.
72-73:021-011
EFFECT OF ANTITRANSPIRANTS ON YIELD OF GRAIN SORGHUM UNDER LIMITED IRRIGATION,
Fuehring, H. D.
New Mexico State University, Agricultural Experiment Station, Clovis.
Agronomy Journal, Vol. 65, No. 3, p 348-351, May-June, 1973. 5 fig, 15 ref.
Descriptors: *Evapotranspiration, *Control, *Grain sorghum. Crop response,
Yield.
Reduction of the degree and length of periods of moisture stress through the
use of antitranspirants to control stomatal opening may increase the amount
of time when photosynthesis takes place thus increasing crop yield with the
water available. The purpose of this study was to determine the proper mater-
ial, method, and timing of application for field use. Under limited irrigation
conditions in the field, grain sorghum was sprayed at various times and rates
with phenylmercuric acetate (PMA), atrazine, and Folicote. Mean grain yield
increases of 5 to 17% were obtained, indicating considerable economic possibil-
ity. Rates of application required were approximately 60 g/ha for PMA, 130
g/ha for atrazine, and 2 liters/ha for Folicote. However, more work is needed
on rates and volume of spray. Application just prior to the boot stage was
more effective than a later application.
72-73:021-012
ESTIMATING TRANSPIRATION RESISTANCE,
Brun, L. J., Kanemasu, E. T., and Powers, W. L.
Kansas State University, Department of Agronomy, Manhattan.
Agronomy Journal, Vol. 65, No. 2, p 326-328, March-April, 1973. 2 fig, 3 tab,
5 ref.
Descriptors: *Transpiration, *Evapotranspiration, *Water utilization, Stomata,
Plant growth, Plant physiology, Plant tissues. Computer models, Lysimeters.
Transpiration resistance was determined in a sorghum canopy by two methods
based on the stomatal resistance of all the leaves on a plant and a third
method based on the stomatal resistance of only the upper three leaves.
Stomatal resistance was measured with the diffusion porometer. The three
methods of determining transpiration resistance included: (i) harmonically
averaging the stomatal resistance of all the leaves on a plant; (ii) dividing
the crop canopy into layers and weighing each layer resistance by its leaf
area index; and (iii) harmonically averaging the stomatal resistances of the
upper three leaves of the plant. Methods 1 and 2 gave almost identical esti-
mates of transpiration resistance. When methods 1 and 3 were evaluated by the
Monteith evapotranspxration model, the evapotranspiration estimate using method
1 gave closer agreement with lysimeter evapotranspiration than when method 3
was used in the model.
72-73:021-013
WATER-USE EFFICIENCY AND ITS RELATION TO CROP CANOPY AREA, STOMATAL REGULATION,
AND ROOT DISTRIBUTION,
Teare, I. D., Kanemasu, E. T., Powers, W. L., and Jacobs, H. S.
Kansas State University, Evapotranspiration Laboratory, Manhattan.
156
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Agronomy Journal, Vol. 65, No. 2, p 207-211, March-April, 1973. 8 fig, 1 tab,
17 ref.
Descriptors: *Evapotranspiration, *Water utilization, Sorghum, Soybeans, Root
development, Lysimeters, Leaves.
The differences in water-use efficiency between sorghum and soybean were com-
pared in terms of leaf area index (LAI), size of root system, canopy stomatal
resistance (RC), net assimilation rate (NAR), and evapotranspiration (ET). The
field water budget was measured by recording the rainfall and irrigation water
applied in relation to the ET as measured with two weighing lysimeters. The
evapotranspiration rates of the two crops began to diverge about August 15.
This was the period when the soybean canopy began to close and the soybean LAI
increased to about 1.5 times that of sorghum. NAR for sorghum during stalk
elongation and heading (Aug. 15) was nearly four times that of soybeans during
that time. Water-use efficiency of sorghum was approximately three times that
of soybeans on dry matter or grain yield bases.
72-73:021-014
ON THE PRESSURE CHAMBER TECHNIQUE FOR ESTIMATING LEAF WATER POTENTIAL IN SORGHUM,
Blum, A., Sullivan, C. Y., and Eastin, J. D.
The Volcani Center, Department of Agronomy, Bet Dagan, Israel.
Agronomy Journal, Vol. 65, No. 2, p 337-338, March-April, 1973. 2 fig, 7 ref.
Descriptors: *Xylem, *Pressure, Pressure measuring instruments, Sorghum.
A leaf sample holder, constructed from Silicon rubber and accomodated into a
brass flange, reduced leaf crushing under pressure. It was found that pressure
chamber readings cannot be directly used as an estimate of leaf water potential,
but should be corrected according to a calibration against a thermocouple
psychrometer determinations of leaf water potential. Different rates of pres-
sure increase in the chamber affected the regression between xylem pressure
and leaf water potential. The regression improved with a greater pressure
rate increase as indicated by smaller error variance estimate. No differences
.were detected between genotypes in this regression. This technique is, there-
fore, useful if worked out according to a calibration curve at a standard rate
of pressure increase.
72-73:021-015
MEASUREMENT OF LEAF WATER POTENTIAL IN WHEAT WITH A PRESSURE CHAMBER,
Frank, A. B., and Harris, D. G.
United States Department of Agriculture, Northern Great Plains Research Center,
Mandan, North Dakota.
Agronomy Journal, Vol. 65, No. 2, p 334-335, March-April, 1973. 1 fig, 7 ref.
Descriptors: *Pressure, *Plant tissues, *Moisture, Xylem, Pressure measuring
instruments, Wheat.
Estimates of leaf water potential obtained with a pressure chamber and with
thermocouple psychrometers were compared for wheat leaves at late tillering
and early heading stages of growth. The methods were linearly related for
both stages of growth, but the equations were different. The pressure chamber
required a separate calibration for estimating water potential of leaves from
two locations on wheat plants.
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72-73:021-016
PORTABLE REFLECTANCE METER FOR ESTIMATING CHLOROPHYLL CONCENTRATIONS IN LEAVES,
Wallihan, E. F.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Agronomy Journal, Vol. 65, No. 4, p 659-662, July-August, 1973. 4 fig, 2
tab, 7 ref.
Descriptors: *Chlorophyll, Measurement, Leaves, Citrus fruits.
The need to measure changes of chlorophyll concentration in citrus leaves
required a nondestructive method of analysis applicable to field use. Light
reflectance in the wavelength region of 600 nm had been shown to be useful for
this purpose but existing reflectance meters were too bulky for field use and
generally required line power. The instrument described here is battery
operated, compact, and measures light reflectance in a band of wavelengths
from 610 nm to 700 nm from four miniature incandescent lamps. Arrangement of
the light unit on a spring clamp permits readings in the field on several
leaves per minute. Calibration against measured chlorophyll concentrations
yields a log curve revealing maximum sensitivity at low chlorophyll concentra-
tions. Tests on leaves from iron-deficient orange trees showed the coefficient
of variability to be in the vicinity of +15%. By reading 20 replicate leaves,
sampling errors were compensated sufficiently to give precision of about +3%.
72-73:021-017
REFLECTANCE, TRANSMITTANCE, AND ABSORPTANCE OF LIGHT BY SUBCELLULAR PARTICLES
OF SPINACH LEAVES,
Gausman, H. W.
United States Department of Agriculture, Agricultural Research Service,
Weslaco, Texas.
Agronomy Journal, Vol. 65, No. 4, p 551-553, July-August, 1973. 2 fig, 16 ref.
Descriptors: *Photosynthesis, Reflectance, Chlorophyll, Energy conversion,
Plant physiology.
/
Subcellular particles of spinach leaves were differentially sedimented and re-
suspended in a buffered sucrose solution. A spectroreflectometer was used to
measure R and trans raittance (T) over the 500- to 2,500-nm wavelength interval
JjtfLTi) on replicated aliquots of five preparations: buffered sucrose solution;
chloroplast preparation; SI, sediment of chloroplast preparation supernatant;
S2, sediment of SI supernatant; and S3, sediment of S2 supernatant. All sus-
pensions of particulates caused less R than the buffered sucrose solution
over the 500- to 650-nm WLI. The chloroplast preparation, compared with the
buffered sucrose solution, increased R over the 750- to 950-nm WLI. The chloro-
plast preparation, compared with the buffered sucrose solution, S2, and S3,
decreased T over the 500- to 1,250-nm WLI; SI decreased T over the 500- to
900-nm WLI. A conclusion was reached that subcellular particles in leaves
contribute to the R and A of IR light.
72-73:021-018
A COMPUTER SIMULATION OF CORN GRAIN PRODUCTION,
Baker, C. H., and Horrocks, R. D.
Missouri University, Agronomy Department, Columbia.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 6,
p 1027-1029, 1031, November-December, 1973. 3 tab, 22 ref.
158
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Descriptors: *Computer models, *Mathematical models, *Plant growth, Corn,
Crop response.
Wheri the ideal simulation model is pictured, it is evident that the trend of
crop research needs to be changed. Instead of researching a plant on a monthly
or seasonal basis, it should be considered on a daily basis. The corn plant,
like most biological systems, is a highly variable and highly buffered system.
A system of this complexity does not respond to average or monthly weather -
instead it is affected each day by that day's weather. The effect of similar
weather on two successive days also differs to a degree since the plant has
changed. In a month's time, the plant can change many times. Development of
a simulation model is not limited by computer capacity, but rather is limited
by lack of mathematical definitions for the basic plant processes.
72-73:021-019
PLANT WATER STATUS IN RELATION TO CLOUDS,
Stansell, J. R., Klepper, B., Browning, V. D., and Taylor, H. M.
Georgia University, Coastal Plain Experiment Station, Tifton.
Agronomy Journal, Vol. 65, No. 4, p 677-678, July-August, 1973. 2 fig, 2 ref.
Descriptors: *Evapotranspiration, *Soil moisture, Plant tissues, Cloud
cover. Clouds.
Clouds can cause significant changes in plant water status in a short time.
Therefore, care should be taken to sample different treatments under comparable
radiation.
72-73:021-020
CONSIDERING IRRIGATED GRASS? TAKE A TIP FROM NEW MEXICO,
Irrigation Age, Vol. 6, No. 10, p 18-19, 32, 34, 35, May, 1972. 2 fig.
Descriptors: ^Grasses, *Range grasses, Wheatgrasses, Switchgrass, Plant group-
ings. Hay, Pastures, Ranges, Irrigation.
They are row cropping irrigated grass in Curry County, New Mexico, and making
the crop pay handsome dividends when the net return is compared to irrigated
wheat and milo. Farmers in the area are literally farming the grass. Several
farmers in and around Clovis have the records to show $70, $80 and more net
profit per acre from irrigated grass. An extensive economic study revealed
a net of $7.81 per acre for irrigated wheat and $16.21 per acre for irrigated
milo. Most popular grasses to date in the area are Jose Tall Wheatgrass for
the cool season pasture and Blackwell Switch Grass for the warm season species.
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Section X
WATER CYCLE
EROSION AND SEDIMENTATION (Group 02J)
72-73:02J-001
SEASONAL SEDIMENT YIELD PATTERNS OF U.S. RIVERS,
Wilson, L.
Environment Consultants, Inc. New York.
Water Resources Research, Vol 8, No 6, p 1470-1479, December 1972. 5 fig,
1 tab, 19 ref.
Descriptors: *Sediment yield. United States, *Seasonal, *Climatology, Erosion,
Rainfall, Runoff, Water yield, Land use, Sediment discharge. Data collections,
*Rivers.
Odentifiers: *Sedihydrograms.
The sedihydrogram is a double log plot of mean monthly sediment yield against
mean monthly water yield. Sediment regimes seen on the sedihydrograra are
explained by a model that relates basin hydrology to the dominance of common
air masses. Mediterranean and continental climate and erosion regimes are
well expressed in U.S. rivers. Mediterranean regimes in the western United
States have a dry summer and a wet winter with strong seasonal contrasts
between early wet season floods and less turbid flow events later in the
wet season. Large sediment yield values may be expected from basins in which
seasonal desiccation alternates with heavy rains. Continental regimes in the
central and eastern United States have a water yield event in late winter
or early spring with a low sediment concentration. Summer storms produce
high concentrations and a low water yield. The summer component of the sedi-
hydrogram is dominant in dry regions but minor in humid areas, where vege-
tation offers effective protection from storms. Basins in eastern humid
states have a sedihydrogram typical of arid regions if strip mining or urban-
ization has had an important effect on the basin hydrology. Most climate
regimes show a seasonal shift in the parameters of the sediment transport
curve, so that an analysis of seasonally grouped data results in improved
equations for relating sediment movement to environmental controls. The
prediction of sediment yield requires that separate consideration be given to
those factors affecting runoff and those affecting sediment concentration.
72-73:02J-002
RUNOFF, EROSION, AND SOLUTES IN THE LOWER TRUCKEE RIVER, NEVADA, DURING 1969,
Glarcy, P.A., Van Denburgh, A.S., and Born, S.M.
Geological Survey, Carson City, Nevada
Water Resources Bulletin, Vol 8, No 6, p 1157-1172, December 1972. 8 fig,
5 tab, 15 ref.
Descriptors: *Water yield, *Sediment yield, *Dissolved solids, *Nevada, Ero-
sion, Runoff, Water chemistry, Hydrogeology, Data collections, Water balance,
Sediment transport.
Identifiers: *Truckee River (Nevada).
The Truckee River heads in the Sierra Nevada at Lake Tahoe, and terminates
in Pyramid Lake. During the 1969 water year, flow about 9 miles upstream
from the mouth (974,000 acre-ft) was almost four times the long-term average,
due mainly to heavy winter rains and spring snowmelt. A short period of low-
altitude rainfall produced the highest concentrations of suspended sediment,
whereas a much longer subsequent period of snowmelt yielded a much greater
total quantity of material. The upper 90% of the basin yielded about 630,000
tons of sediment at the Nixon gage, whereas an estimated 6.8 million tons was
contributed by erosion of about 200 acres of river bank below the gage.
Solute content at the gage ranged from 80 to 450 rag/liter, dominated by calcium,
sodium, and bicarbonate, plus silica in the most dilute snowmelt and chloride
in the most concentrated low flows. Solute load totaled about 130,000 tons,
of which the principal constituents in Pyramid Lake-sodium plus equivalent
160
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bicarbonate and chloride-amounted to almost 40,000 tons. The total solute
load during a year of average flow may be 45,000-55,000 tons, including
18,000-22,000 tons pf principal lake constituents.
72-73:02J-003
PHYSICO-CHEMICAL FACTORS IN EROSION OF COHESIVE SOILS,
Sargunam, A., Riley, P., Arulanandan, K. and Krone, R.B.
California University, Davis, Department of Civil Engineering.
Journal of the Hydraulics Division, American Society of Civil Engineers,
Vol 99, No HY3, p 555-558, March 1973. 2 fig, 1 tab, 6 ref.
Descriptors: *Soil erosion, *Saline soils, *Cohesive soils, *Ion exchange,
*Leaching, Pore water, Soil chemistry, Calcium, Sodium, Magnesium,Chlorides.
Critical hydraulic shear stress, defined as that stress which must be
exceeded to cause erosion of a soil, is related to mechanical properties of
the soil. Susceptibility of a cohesive soil to erosion also depends on
the pore fluid composition. Cylindrical specimens were prepared by consoli-
dation from slurries in which the pore fluid had been altered by the addition
of Na, or Mg, or Ca chlorides. Using sodium salt, the critical shear
stress increased markedly with increasing concentration even through the SAR
was also increasing. The change in erosion rate for the calcium soil,
however, is about one-twentieth that of the sodium soils. This probably
results from the stronger interparticle bonds and the lesser hydration asso-
ciated with absorbed calcium ions. The higher the interior pore concentration
or the lower its SAR the greater will be the cohesion when the pore space
around surface particles swells to a new near-equilibrium volume. Increasing
the concentration or reducing the SAR of eroding fluid will also increase
the equilibrium cohesion of surface particles and limit surface particle swell.
72-73:02J-004
FIELD CALIBRATION AND EVALUATION OF A NUCLEAR SEDIMENT GAGE,
Welch, N.H., and Allen, P.B.
Agricultural Research Service, Chickasha, Oklahoma. Southern Great Plains
Watershed Research Center.
Water Resources Research, Vol 9, No 1, p 154-158, February 1973. 3 fig, 2 tab,
8 ref.
Descriptors: *Suspended load, *Sediment load, *Gaging, *Gages,*Nuclear meters,
Sampling, Calibrations, Instrumentation.
Identifiers: *Nuclear sediment gages.
Nuclear sediment gage readings were compared to stream cross-sectional sedi-
ment concentrations for several storm events over a 3-year period. Cali-
bration curves, developed by least-squares analysis, are presented for indi-
vidual and combined storm events. Correlation coefficients for individual
or combined storm events ranged from minus 0.86 to minus 0,99, and all were
significant at the 1% level. Standard errors of estimate ranged from plus
minus 172 to plus minus 1884 ppm. Sediment concentrations predicted with
the calibration curves developed in this study were accurate enough for
most applications. Although the particular nuclear gage used is probably
unsatisfactory for general use, the principle of monitoring sediment con-
centrations by nuclear techniques appears sound and feasible.
72-73:02J-005
SEDIMENT YIELD COMPUTED WITH UNIVERSAL EQUATION,
Williams, J.R., and Berndt, H.D.
Agricultural Research Service, Riesel Texas. Soil and Water Research Division.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
98, No HY12, Paper 9426, p 2087-2098, December 1972. 3 fig, 3 tab, 8 ref,
append.
Descriptors: *Sediment yield, *Soil erosion, *Mathematical models, Equations,
Sedimentation, Grassed waterways, Erosion control, Reservoir silting, Sediment
discharge, Vegetation effects, Watershed management.
161
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Sediment yield from watersheds may be predicted by modifying the Universal
Soil Loss Equation and using a delivery ratio. All factors of the equation
except the rainfall factor were modified to increase computational efficiency.
In addition, the erosion-control practice factor was expanded to include the
separate effect of grassed waterways. Delivery ratios were computed for five
small blackland watersheds and related to watershed characteristics. Ste-wise
multiple regression was used to develop equations for predicting delivery
ratios. The regression analysis showed that slope of the main stem channel
explains about 99% of the variation. The modified Universal Soil Loss Equa-
tion and the equation for predicting delivery ratios form a sediment yield
model that should be useful in reservoir design and water quality studies.
72-73:02J-006
PREDICTING SEDIMENT YIELD IN WESTERN UNITED STATES,
Flaxman, E.M.
Soil Conservation Service, Portland, Oregon. Engineering and Watershed Planning
Unit.
Journal of the Hydraulics Division, American Society of Civil Engineers,
Vol 98, No HY12, Paper 9432, p 2073-2085, December 1972. 1 fig, 2 tab, 5 ref.
Descriptors: *Sediment yield, *Erosion, *Equations, *Sheet erosion, Statistics,
Statistical methods, Regression analysis. Sedimentation, Land use. Climates,
Soil erosion, Vegetation effects, Soil physical properties.
Identifiers: Western U.S.
An equation for predicting the average annual sediment yield from sheet
erosion was developed through multiple-regression analysis. Most of the
variation in yield is explained with data obtained by measurement of four
watershed characteristics. A climatic factor as indirect expression of vege-
tative cover), the average watershed slope, and two soil factors are the
variables used. A good correlation of computed with measured sediment yields
is obtained except at the lower rates of sedimentation. Improvements in
predictive values can be achieved with experience in judging the necessary
adjustments in the vegetative cover factor, through soil sampling, and by
use of longtime sediment yields. The data selected for this analysis exclude
the influence of extensive gully or stream bank erosion
72-73:02J-007
CHAPTER V: SEDIMENT CONTROL METHODS: C. CONTROL OF SEDIMENT IN CANALS,
American Society of Civil Engineers, New York. Task Committee for Prepara-
tion of the Sedimentation Manual.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol
98, No HY9, p 1647-1689, September 1972. 20 fig, 1 tab, 37 ref, append.
Descriptors: "Canals, *Desilting, *Sediment control, Bed load. Channels,
Diversion structures, Hydraulic models, Hydraulics, Scour, Sedimentation,
Settling basins, Sluices, Streamflow, "Suspended sediments, Streams, Velocity,
Dredging, Sediments, Sediment transport. Canal design.
Identifiers: Sediment excluders, Diversion works, Ejectors, Headworks.
Sediment transported by natural streamflow has often presented major problems
to the canal designer. To prevent clogging and costly maintenance operations,
sediment must be removed from the water at the canal intake or transported
through the canal system with a minimum of accumulation within the canal prism
and structures. Complete elimination of the sediment at the diversion point
generally is impractical and too costly in most cases. However, a combina-
tion of sediment control at the headworks and design of canal hydraulics to
minimize deposition through the canal length can be used to provide practical
solutions to the problem. Some factors to be considered in canal design
are: (1) amount and type of sediment to be removed or carried into the canal
system, (2) type of earth materials through which the canal is to be construc-
ted, and (3) type of lining, when used. Structures that reduce the amount of
bedload entering canals are diverters or ejectors; to remove suspended small
particles, some type of settling basin placed in the canal just downstream
from the headworks is used. Several structures are shown and discussed.
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72-73:02J-008
SOIL AND WATER LOSSES AS AFFECTED BY TILLAGE PRACTICES,
Onstad, C.A.
United States Department of Agriculture, Agricultural Research Service, Soil
and Water Conservation, Brookings, South Dakota.
Transaction of the American Society of Agricultural Engineers, Vol 15, No 2,
p 287-289, March-April, 1972. 1 fig, 6 tab, 8 ref.
Descriptors: *Soil conservation, *Water conservation, *Erosion control, Soil
erosion, Agricultural runoff, Cultivation, Mulching, Sediment control.
Four corn tillage treatments were compared with respect to their effect on soil
and water losses in a 6-year study. The treatments tested were: conventional
tillage, mulch tillage, till-planted up and down slope, and till-planted
on the contour. Higher runoff on the conventionally tilled plots and lower
runoff on the contoured till-plant tteatment were significant at the 1-per-
cent level. Runoff differences were not significant for the mulch-tilled
and the till-planted up and down slope. The differences in soil loss were
also significant in the same manner as runoff. These measurements were made
on slope lengths of 72.6 ft. Longer slopes would have more soil loss per
unit area. Extrapolated to a 300-foot slope length, the soil loss from the
conventional treatment would have exceeded 5 tons per acre even though
growing season rainfall was only 80 percent of normal.
72-73:02J-009
PREDICTION OF RUNOFF AND EROSION FROM NATURAL RAINFALL USING A RAINFALL SIMU-
LATOR,
Young, R.A., and Burwell, R.E.
Agricultural Research Service, Morris, Minnesota. North Central Soil Conser-
vation Research Center.
Soil Science Society of America Proceedings, Vol 36, No 5, p 827-830,
September-October 1972. 3 fig, 4 tab, 6 ref.
Descriptors: *Erosion, *Rainfall-runoff relationships, *Simulated rainfall,
*Rainfall simulators, Artificial precipitation, Model studies, On-site tests,
Soil erosion, Runoff.
To interpret and apply the results of studies of runoff and erosion using simu-
lated rainfall, it is necessary to know the relative effects of natural vs.
simulated rainfall. A comparison was made of the soil and water losses from
three natural storms and three simulated storms on cultivated fallow plots
under similar rainfall and soil conditions. Soil losses from the three
simulated storms averaged 77% of those from the natural rainstorms, with an
average erosion index value for the simulated storms of 78% of that for natural
rainstorms. The runoff from the simulated storms compared quite closely to
runoff from the natural storms.
72-73:02J-010
WATER-SEDIMENT SPLITTER FOR RUNOFF SAMPLES CONTAINING COARSE-GRAINED SEDIMENT,
Fleming, W.G., and Leonard, R.A.
United States Department of Agriculture, Watkinsville, Georgia.
Soil Science Society of America Proceedings, Vol 37, No 6, p 961-962,
November-December 1973. 2 fig, 1 tab.
Descriptors: *Suspension, *Suspended solids, *Sampling, Sediment sorting,
Sediment yield, Runoff, Erosion.
A water-sediment sample splitter was designed and constructed for dividing
samples up to 20 liters into three equal and representative smaller samples
for chemical and physical analyses. This funnel-shaped device with a
mechanical agitator divides samples containing particles up to 2 mm without
first separating the sediment from the water. Evaluation showed that the
splitter divided samples containing coarse sediments into three parts with
a distribution of 33% + 2% in each. The device has application in assuring
representative samples of runoff from water shed or similar runoff studies.
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72-73:02J-011
DISPERSION OF CONTAMINATED SEDIMENT BED LOAD,
Shen, H.W. and Cheong, H.F.
Colorado State University, Department of Civil Engineering, Fort Collins.
Journal of the Hydraulics Division, American Society of Civil Engineers,
Vol 99, No HY11, p 1947-1965, November 1973. 15 fig, 2 tab, 6 ref.
Descriptors: *Bed load, ^Dispersion, *Erosion, Sedimentation, Hydraulics,
Water pollution sources, Radioactivity, Sediment transport.
Dispersion of instantaneously released contaminated bed sediments in analyzed
within the framework of a Lagrangian probabilistic model. The time and space
concenctarion distributions, with the parameters computed on the basis of
the same rate of mass movement and a constant rate of spread, approach Gaussian
form asymptotically. A procedure is suggested for deriving approximations to
the envelopes of the distribution curves parameterized by either the time
or distance. The method is also applicable when the shape factor of the
particle step length distribution takes on nonintegral values greater than
one. Where the formality approximation is satisfactory, the critical duration
for a given degree of pollution varies in direct proportion to the square
root of the distance from the source. Graphical results for the critical
time limits for the absorption of radiation from contaminated particles for
different positions of the subject are also presented.
72-73:02J-012
EFFICIENT UTILIZATION OF WATER THROUGH LAND MANAGEMENT,
Cormack, J.M.
Rhodesia Department of Conservation and Extension.
Rhodesia Agricultural Journal, Vol 69, No 1, p 11-16, January-February, 1972.
6 fig.
Descriptors: *Erosion, *Water quality, Soil conservation, Water conservation,
Sedimentation, Land management.
The problem of erosion in Rhodesia is explained. Possible solutions and
government programs are outlined.
72-73:02J-013
EFFECT OF CORN STOVER ON PHOSPHORUS IN RUN-OFF FROM NONTILLED SOIL,
Ketcheson, J.W. and Onderdonk, J.J.
Guelph University, Department of Land Resource Science, Guelph, Canada.
Agronomy Journal, Vol 65, No 1, p 69-71, January-February 1973. 4 tab, 6 ref.
Descriptors: *Nutrient removal, *Phosphorus, *Runoff, Erosion, Mulching,
Corn, Soil conservation, Water pollution sources.
The effect of stover on soil and phosphorus (P) removal was determined for a
well-drained till soil with 7% slope. Corn was planted without tillage after
32P-tagged P fertilizers was applied broadcast and covered with a corn stover
mulch in one treatment or left bare in a second treatment. Run-off was
collected and analyzed from one simulated and from two natural rainfall
events. Stover reduced soil P in run-off by 65% and fertilizer P by 97%.
These reductions were achieved by a decrease in total run-off and by a decrease
in the concentration of suspended soil in it. Of the 29 kg of fertilizer P
applied per ha, 3,85 kg and 0.13 kg were removed over all run-off events from
the no stover and stover treatments, respectively. This corresponded to 8.5
and 1.3%, respectively, of the total P removal, which varied from 45 kg/ha
without stoved to 10 kg/ha with stover. The liquid fraction of the run-off
carried the least amounts of either soil or fertilizer P.
72-73:02J-014
CONCEPTS OF CONSERVATION TILLAGE SYSTEMS USING SURFACE MULCHES,
Wittmuss, H.D., Triplett, G.B., Jr., and Greb, B.W.
Nebraska University, Agricultural Engineering Department, Lincoln.
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Presented at National Conservation Tillage Conference, March 28-30, 1973.
Des Moines, Iowa. Technical Paper No 1, 14 p, 1 tab, 43 ref.
Descriptors: *Soil conservation, *Erosion, Soil erosion, Water conservation,
Cultivation, Erosion control, Erosion rates.
A brief summary of the need and effects of conservation tillage is presented.
Effects on soil erosion of some tillage practices are listed.
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Section XI
WATER CYCLE
CHEMICAL PROCESSES (Group 02K)
72-73:02K-001
CHEMISTRY AND OCCURRENCE OF CADMIUM AND ZINC IN SURFACE WATER AND GROUNDWATER,
Hem, J.D.
Geological Survey, Menlo Park, California. Water Resources Division.
Water Resources Research, Vol 8, No 3, p 661-679, June 1972. 11 fig, 3 tab,
41 ref.
Descriptors: *Water chemistry, *Zinc, *Cadmium, Surface waters, Groundwater,
Trace elements, Spectrophotometry, Water analysis. Path of pollutants.
Water pollution sources, Carbonates, Solubility, Fallout.
The median concentration of zinc in 726 filtered samples of water taken from
rivers and lakes of the United States in November 1971 was close to 20
migrograms per liter, and the mediam concentration of cadmium was a little
below 1 microgram per liter. The concentrations of both elements tended to
be consistently higher in water from northeastern and southeastern
states. Chemical thermodynamic calculations summarized by solubility graphs
suggest that the carbonate and hydroxide solubilities of these elements
are higher than the concentrations commonly found, but for 24 to 80
analyses for which chemical equilibrium computations could be made, saturation
with respect to one or both of the metals was closely approached. Zinc
solubility may also be controlled by silicate in some waters. Biological
factors and sorption by stream sediments may also be significant controls.
Concentrations of cadmium above 10 micrograms per liter may be stable in
water having low total solute concentrations and pH and can be difficult to
remove by conventional water treatment processes.
72-73:02K-002
CHLORIDE BALANCE OF SOME FARMED AND FORESTED CATCHMENTS IN SOUTHWESTERN
AUSTRALIA,
Peck, A.J., Hurle, D.H.
Commonwealth Scientific and Industrial Research Organization, Wembley
(Australia)
Water Resources Research, Vol 9, No 3, p 648-657, June 1973. 1 fig, 5 tab,
25 ref.
Descriptors: *Saline water, *Leaching, *Salt balance, *Australia, Water
quality, Water chemistry, Water balance. Chlorides, Vegetation effects, Land
use, Water pollution sources, Saline soils.
Loss of chloride in streamflow from forested catchments in southwestern
Australia is only slightly greater than the total annual input from rain and
dust. However, salt flow from catchments in which a significant area of the
forest vegetation has been cleared for farming is much larger and exceeds
salt input by up to 690 kg/ha per yr, or a factor of 21. The net loss
of Cl results from decreased storage in catchment soil water. Removal of
the forest begetation increases groundwater discharge of catchments by amounts
ranging from about 1 to 13 cm per year. Characteristic times for equilib-
ration of Cl input and loss on farmed catchments are estimated to range from
30 to 400 years. In equilibrium the salty streams draining farmed catchments
would yield water with Cl concentration acceptable for drinking.
72-73:02K-003
SIMULATION OF HYDROCHEMICAL PATTERNS IN REGIONAL GROUNDWATER FLOW,
Schwartz, F.W., and Domenico, P.A.
Alberta University, Edmonton. Department of Geology.
Water Resources Research, Vol 9, No 3, p 707-720, June 1973. 7 fig, 8 tab, 20 ref.
166
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Descriptors: *Water chemistry, *Hydrogeology, *Simulation analysis, *Ground-
water basins, Mass transfer, Equilibrium, Kinetics, *Canada, Mathematical
models, Leaching, Weathering, Geochemistry.
The chemical state of a regional groundwater system in which several processes
are acting is described by a simulation model that incorporates partial equil-
ibrium, mass transfer, and reaction kinetics. Mineral dissolution, saturation
constraints in dissolution, the degree of saturation, partial pressures of
C02, reaction kinetics, and the residence time of the groundwater flow play
different roles in determining the spatial distribution of ionic constituents.
Simultaneous evaluation of several geochemical processes permits the study
of interdependent phenomena such as shifts in equilibrium concentrations
resulting from the addition of common ions by cation exchange or sulfate
reduction processes. The utility of the model was demonstrated by applying
it to the groundwater reservoir in the Upper Kettle Creek, Ontario, Canada,
where a favorable comparison was achieved between the real and the theoretical
hydrochemical patterns.
72-73:02K-004
SIMULTANEOUS TRANSPORT OF CHLORIDE AND WATER DURING INFILTRATION,
Kirna, C., Nielsen, D.R., Biggar, J.W.
California University, Davis. Department of Water Science and Engineering.
Soil Science Society of America Proceedings, Vol 37, No 3, p 339-345,
May-June 1973. 7 fig, 1 tab, 27 ref.
Descriptors: *Leaching, *Diffusion, *Chlorides, *Infiltration, Mass transfer,
Convection, Dispersion, Path of pollutants, Mixing, Soil water movement,
Water chemistry, Tracers, Tracking techniques, Radioisotopes.
Identifiers: Chloride transport.
Displacement of chloride during infiltration was studied using soil columns
for two cases: chloride initially spread on.the soil surface; and chloride
initially mixed with the soil. Chloride was applied as CaC12 labeled with
Cl-36. In conjunction with chloride activity measurement, gamma-ray attenua-
tion measurement was used for monitoring the water content distribution during
the simultaneous flow of chloride and water. Treatments included different
levels of initial soil water content and different levels of water saturation
at the soil surface during infiltration. The equations describing vertical
water flow and miscible displacement of chloride were solved numerically.
Experimental and calculated chloride distributions were in agreement. Chloride
apparent diffusion coefficients estimated for pore water velocities less than
0.01 cm per min were nearly equal to those for molecular diffusion only.
Initial soil water content did not influence the depth of chloride displace-
ment for a given quantity of water infiltrated. Keeping the water content at
the soil surface below saturation resulted in a deeper and more complete dis-
placement of chloride.
72-73:02K-005
RELATIONSHIP BETWEEN THE CARBON ISOTOPE COMPOSITION OF SOIL C02 AND DISSOLVED
CARBONATE SPECIES IN GROUNDWATER,
Rightmire, C.T., and Hanshaw, B.B.
Geological Survey, Washington, D.C.
Water Resources Research, Vol 9, No 4, p 958-967, August 1973. 4 fig, 3 tab,
29 ref.
Descriptors: *Stable isotopes, *Carbon, *Isotope fractionation, *Water chem-
istry, *Hydrogeology, Groundwater, Groundwater movement, Provenance, Clima-
tology, Tracers, Florida, Soil water, Soil gases.
Identifiers: *Carbon isotopes.
To understand the carbonate geochemistry of an aquifer system, it is helpful
to determine the sources of carbon in the dissolved carbonate species.
Samples of ground litter, soil organic matter, soil CO2 and groundwater were
collected in the area of recharge to the principal artesian aquifer of
central Florida and were analyzed for C-13 content. Analytical results yield
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consistent C-13/C-12 values for soil organic matter; delta C-13 (PDB) + 23
plus or minus 1 part per thousand. The C-13/C-12 ratio of the litter samples
ranges from delta C-13 (PDB) of -18.2 to -29.5 parts per thousand and indicates
the presence of both Calvin and Hatch-Slack cycle plants. The C-13/C-12 of
the soil CO2 ranges from -14.7 to -21.3 parts per thousand, which is consistent
with the trend observed in the litter. The relationship between C-13/C-12 of
the dissolved carbonate and the percent calcite saturation indicates that the
C of the source CO2 is within the range expected for a humid, subtropical en-
vironment.
72-73:02K-006
HYDROCHEMICAL ENVIRONMENTS OF CARBONATE TERRAINS,
Drake, J.J., and Harmon, R.S.
McMaster University, Hamilton (Ontario). Department of Geography,
Water Resources Research, Vol 9, No 4, p 949-957, August 1973. 4 fig, 4 tab,
22 ref.
Descriptors: *Karst hydrology, *Water chemistry, Water analysis, Geochemistry,
Statistics, Carbonate rocks, Hydrogeology, 'Pennsylvania.
Waters within a carbonate aquifer may be classified on a hydrologic basis.
To test the classification method, 166 reliable chemical analyses of carbonate
waters from Pennsylvania were grouped on a hydrologic basis, and the groupings
were tested by a stepwise linear discriminant function analysis. Two para-
meters (degree of calcite saturation and eqilibrium-carbon dioxide partial
pressure) are sufficient to distinguish the groups at the 0.005 confidence
level and provide a reliable way. to examine the geochemical evolution of the
waters in the carbonate drainage basin.
72-73:02k-007
POTENTIOMETRIC TITRATION OF SULFATE IN WATER AND SOIL EXTRACTS USING A LEAD
ELECTRODE,
Goertzen, J.O., and Oster, J.D.
Agricultural Research Service, Riverside, California. Salinity Lab.
Soil Science Society of America Proceedings. Vol 36, No 4, p 691-693, 1972.
Identifiers: Electrodes, Lead, *Potentionmetric titration, Soils, *Sulfates,
Titration, Water pollution sources.
Sulfate concentrations in natural waters and soil water extracts were deter-
mined seimautomatically using a pb-ion electrode to indicate the solution
potential change at the endpoint, a constant flow device to deliver the ti-
trant, a pH-raV meter to measure the potential, and a strip chart recorder
to plot the solution potential thus indicating the endpoint. Sulfate con-
centrations as low as 0.5 meg/liter in the sample solution were determined
by the potentiometric titration system. This semiautomated direct titration
of sulfate has the advantages of increased sensitivity and speed as compared
with the precipitation method.
72-73:02K-008
DETERMINATION OF NITRATES IN SOIL EXTRACTS,
Kowalenko, C.G. and Lowe, L.E.
British Columbia University, Department of Soil Science, Vancouver, British
Columbia, Canada.
Soil Science Society of America Proceedings, Vol 37, No 4, p 660, July-
August, 1973. 7 ref.
Descriptors: *Water chemistry, Nitrates, Soil chemistry, Ions.
A variation of a method for nitrate analysis of water samples developed by West
and Ramachandran (1966) is presented. The method can be used on soil samples
in place of the phenoldisulfonic acid method with very comparable results.
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72-73:02K-009
ON SOLUBILITY AND SOLUBILITY PRODUCE CONSTANTS,
Nakayama, F.S.
United States Water Conservation Laboratory, Phoenix/ Arizona.
Soil Science Society of America Proceedings, Vol 37, No 4, p 661-662,
July-August, 1973.
Descriptors: *Solubility, Aqueous solutions, Chemical properties, Leaching,
Saturation, Solvents.
A comment on a previously published article is voiced. A new method for
determining solubility product constant is mentioned and debated but not
fully presented here.
72-73:02K-010
PRESERVATION OF SOIL SAMPLES FOR INORGANIC NITROGEN ANALYSES,
Nelson, D.W., and Bremner, J.M.
Purdue University, Department of Agronomy, Lafayette, Indiana.
Agronomy Journal, Vol 64, No 2, p 196-199, March-April, 1972. 3 tab, 23 ref.
Descriptors: *Nitrates, *Inorganic compounds, *Nitrogen, Nitrogen cycle,
Nitrogen fixation, Nitrogen compounds, Soil analysis.
Studies of the effects of several pretreatments and storage conditions on the
inorganic N contents of 10 Iowa soils indicated that storage at -5 C in an
airtight container is a satisfactory method of preserving field-;moist soil
samples for inorganic N analyses. Storage at this temperature did not cause
a significant change in the exchangeable ammonium N, nitrate N, or fixed
ammonium N contents of the soils studied. Air-drying at 22 C increased the
inorganic N contents of most of the soils studied, with the average increase
4.2 ppm for exchangeable ammonium N, 1.7 ppm for nitrate N, and 4.4 ppm for
fixed ammonium N. Oven-drying at 55 C resulted in a slightly larger increase
in exchangeable ammonium N than did air-drying at 22 C, and drying at 22 C
in ammonia-free air caused a smaller increase in exchangeable ammonium N
than drying at the same temperature in laboratory air. Storage of air-dried
soils in paper bags for 9 months led to marked increases in their inorganic
N -contents.
72-73:02K-011
IONIC ACTIVITY COEFFICIENTS IN WATER SOLUTIONS CALCULATED BY MEANS OF
NOMOGRAPHS,
Zanker, A.
Kiriat-Jam "G", P.O. Box 11, Israel.
Water Research, Vol 6, No 2, p 191-195, February, 1972. 2 fig, 2 ref.
Descriptors: *Ions, Ion exchange, Solubility, Soil chemistry, Water chemistry.
A knowledge of ionic activity coefficients is a matter of importance in
water research. The ionic activity coefficients in water solutions are
functions of the ionic strength, the valency of the ion, and the effective
ionic radius (for low ionic strengths only).
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Section XII
WATER SUPPLY AUGMENTATION AND CONSERVATION
SALINE WATER CONVERSION (Group 03A)
72-73:03A-001
EFFECT OF H2SO4 IN HIGH SODIUM IRRIGATION WATER ON THE GROWTH OF PEAS AND
BEANS IN CALCAREOUS SOILS,
Ryan, J., Miyamoto, S., and Bonn, H.L.
Arizona University, Department of Soils, Water, and Engineering. Tucson.
Agronomy Journal, Vol 65, No 6, p 999-1000, November-December, 1973. 2 fig,
1 tab, 6 ref.
Descriptors: *Salinity, *Alkalinity, Sodium, Water quality, Alkaline soils,
Alkaline water, Neutralization.
Preliminary experiments were conducted to evaluate the addition of H2SO4 to
high Na water for the purpose of preventing or reducing plant uptake of Na
by increasing the solubility of Ca. The addition of up to 4 meq/liter of
H2S04 to irrigation water containing 1 to 40 meq/liter of NaCl had no
significant effect on the growth of peas and beans cropped twice in cal-
careous soils in greenhouse experiments. However, H2S04 had an adverse
effect at NaCl concentrations of 60 and 80 meq/liter. Sodium concentrations
greater than 10 meq/liter appeared to decrease the yield of both plants.
A leaching fraction of 0.3 +0.05 was maintained. The Na content of the
irrigation water increased, but no reduction in Na content was observed
with the H2S04 treatment. The Ca content was not affectes. The results
suggest that this practice was ineffective at the H2S04 concentration
range studied.
170
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Section XIII
WATER SUPPLY AUGMENTATION AND CONSERVATION
WATER YIELD IMPROVEMENT (Group 03B)
72-73:036-001
DSE OF PRODUCTION FUNCTIONS TO EVALUATE MULTIPLE USE TREATMENTS ON
FORESTED WATERSHEDS,
O'Connell, P.F., Brown, H.E.
Forest Service (USDA) Tucson, Arizona, Rocky Mountain Forest and Range
Experiment Station.
Water Resources Research, Vol 8, No 5, p 1188-1198, October 1972. 8 fig,
2 tab, 15 ref,
Descriptors: *Water yield improvement, *Forest management, *Watershed
management, *Arizona, Clear-cutting, Optimization, Economics, Water
conservation, Input-output analysis, Land management, Water management
(applied) .
Identifiers: *Beaver Creek Watershed (Ariz.)
Alternative land treatments on Beaver Creek watersheds in northern Arizona
were designed to increase water yield within a multiple use framework
that includes timber, wildlife habitat, herbage, recreation, sediment,
and environmental quality. Total, average, and marginal economic concepts
are used to demonstrate the most efficient way to manage an area for one
output. Even without price information, a range of 'best' input combinations
can be identified. To determine how an area can be managed for multiple
products in the most efficient way, product-product functions were developed
for water, timber herbage for five strip cutting alternatives. These
functions indicate the supplementary, complementary, and competetive
outputs obtained from a given expenditure. To account for the dynamic
nature of production in the National Forests, outputs and costs were evaluated
over a 90-year period.
72-73-03B-002
CHANGES IN WATER YIELD OF SMALL WATERSHEDS BY AGRICULTURAL PRACTICES,
Richardson, C.W.
United States Department of Agriculture, Riesel, Texas.
Transactions of the American Society of Agricultural Engineers, Vol 15,
No 3, p 591-593, May-June, 1972. 7 fig, 5 ref.
(See 72-73:02E-004)
171
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Section XIV
WATER SUPPLY AUGMENTATION AND CONSERVATION
USE OF WATER OF IMPAIRED QUALITY (Group 03C)
72-73:03C-001
SOIL WATER REGIME IN ECONOMIC EVALUATION OF SALINITY IN IRRIGATION,
Bresler, E. and Yaron, D.
Volcani Institution of Agricultural Research, Bet-Dagan (Israel).
Water Resources Research, Vol 8, No 4, p 791-800, August 1972. 2 fig, 1 tab,
10 ref.
Descriptors: *Soil water, *Irrigation, *Salinity, *Irrigation efficiency,
Irrigation water, Water quality, Water quantity, Irrigation practices,
Economics, Evaluation, Estimating, Computer models. Statistical models,
Optimization, Systems analysis.
Identifiers: Soil water suction.
In regions with a Mediterranean climate and a semiannual alternation of rainy
and irrigation seasons, it seems more efficient to control salinity by regu-
lating the soil water regime, as an alternative to control by leaching. The
soil can be leached during the rainy season by rain and/or irrigation and
the total water suction can be controlled during the 'crop-growing irrigation
season by altering the water regime. Presented is an approach for the short-
run determination of the economically optimal quantity-quality combination
of the irrigation water during the irrigation season, when the soil water
regime and the soil salt status are changed simultaneously. A field irrigation
water requirement experiment and computer and statistical models are used
to estimate the functional relationships between the total water suction
and the man-controlled variables: quantity and quality of irrigation water
and frequency of irrigation. Data from the irrigation experiment show
that situations exist in which increasing the depth of wetting lead to
increasing salt concentration in the soil solution while at the same time
decreasing the total and average soil water suctions.
72-73:03C-002
PRESENT AND FUTURE SALINITY OF THE COLORADO RIVER,
Holburt, M.B. and Valentine, V.E.
Colorado River Board of California, Los Angeles.
Paper, American Society of Civil Engineers, Hydraulics Division, Specifica-
tions Conference, University of Iowa, Iowa City, August 1971. 32 p, 3 fig,
7 tab, 8 ref, append.
Descriptors: *Salinity, *Irrigation effects, *Salt balance, *Water utiliza-
tion, *Water pollution. Dissolved solids, Irrigation water. Reservoir evapo-
ration, Saline water, Depletion, Forecasting, Inflow, Damages, Salts.
Identifiers: *Colorado River Basin, Colorado River Compact, Upper Colorado
River Basin, Lower Colorado River Basin.
Colorado River salinity causes severe problems for irrigators in California
and Arizona, some in the Upper Colorado River Basin, and affects the urban
areas in southern California coastal plain. Continuing growth and develop-
ment in the Colorado River Basin States will increase the river salinity
substantially unless preventive measures are taken. Salinity of the river
and its tributaries is caused by salts from natural and man-made sources,
and by the consumptive use of water as it flows downstream. Irrigation
is the predominant man-made activity that increases the river salinity.
Evaporation from reservoirs and river salinity. Evaporation from reservoirs
and river surfaces, and phreatophyte losses also have a significant impact
on the salinity of the river. The 1970 salinity report of the Colorado
River Board concluded that a combination of salinity control projects would,
reduce the river salinity. Approximately 2.8 million tons of salt per
year could be removed from the river system if these control projects were
constructed.
172
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72-73:030-003
INTERACTION OF TEMPERATURE AND SALINITY ON SUGAR BEET GERMINATION,
Fracois, L.E. and Goodin, J.R.
Agricultural Research Service/ Riverside. Soil and Water Conservation Research
Division.
Agronomy Journal, Vol 64, No 3, p 272-273, 1972. 1 tab, 1 fig, 11 ref.
Descriptors: *Environmental effects, *Salt tolerance, *Germination, *Limiting
factors, *Thermal stress, Agriculture, Saline soils, Southwest U.S., Soil-
water-plant relationships, Temperature, Salinity, Heat resistance, Physiolog-
ical ecology, Plant physiology, *Sugar beets, Sugar crops.
Because high temperatures and soil salinity adversely affect sugarbeet
germination in the southwestern United States, the interaction of temperature
and salinity on germination was studied by a modification of the standard
blotter technique. The interaction was highly significant. Salinity had
little effect on germination at 10 degrees C and 15 degrees C but was increas-
ingly inhibitory as temperature increased from 25 degrees C to 40 degrees C.
Germination was maximum at 25 degrees C, with low salinity, and almost com-
pletely inhibited at 45 degrees C with all salinity levels. Of the four
varieties studied, 'US-H2', 'US-H6', 'US-H81, and 'HH-5', germination of
the US-H2 variety was most sensitive to salinity over the 30 degrees C to
40 degrees C range.
72-73:03C-004
SALT TOLERANCE OF SAFFLOWER VARIETIES DURING GERMINATION,
Ghorashy, S.R., Sionit, N., and Kheradnam, M.
Pahlavi University, Shiraz (Iran) College of Agriculture.
Agronomy Journal, Vol 64, No 2, p 256-257, March-April 1972. 1 fig, 8 ref.
Descriptors: *Salt tolerance, *Oilseed crops, *Germination, *Plant physiology,
*Varieties, Crop response, Salinity, Saline soils. Growth chambers, Agronomic
crops. Viability, Soil environment, Soil-water-plant relationships, Irri-
gation effects.
Identifiers: Plant section.
Safflower is an oil-seed crop well adapted to the semi-arid regions of the
world. In these areas accumulation of salts in irrigated soils may reduce
germination, growth, and eventually the yield of this crop. Varietal
differences with respect to salt tolerance have been observed in various
crop species. Knowledge of such differences in safflower is of potential
importance. Effects of seven salinity levels (0 to 2 percent NaCl) on
germination of three safflower varieties were determined under controlled
temperature. The varieties were 'Ute1, Iranian local 3151 showed the
least reduction in percent germination, as compared with the other two at
NaCl concentrations greater than 1 percent.
72-73:03C-005
SALINITY-OZONE INTERACTIONS ON PINTO BEAN: INTEGRATED RESPONSE TO OZONE
CONCENTRATION AND DURATION,
Maas, E.V., Hoffman, G.J., Rawlins, S.L., and Ogata, G.
United States Department of Agriculture, Agricultural Research Service,
Salinity Laboratory, Riverside, California.
Journal of Environmental Quality, Vol 2, No 3, p 400-404, July-September, 1973.
2 fig, 2 tab, 13 ref.
Descriptors: *Salinity, *Air pollution effects, *Air pollution. Plant growth,
Beans, Leaves, Ozone, Oxidation, Osmotic pressure, Water pollution effects.
This investigation was conducted to determine the integrated effects of
concentration and duration of ozone exposure on the injury, growth,and mineral
composition of pinto bean during rapid vegetative growth and to evaluate
the interactive effects of salinity. Plants were grown in controlled
environment chambers in non-saline and two saline nutrient solution cultures
having osmotic potentials of -0.4, -2.4, and -4.4 bars, respectively. Ozone-
free plants were compared with plants treated daily for 2 weeks with ozone
173
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doses of from 0.15 to 0.90 ppm-hour. Plant injury and reduction in growth
were sigmoidal functions of ozone dose. Plant tolerance thresholds were
found for both concentration and duration of ozone exposure. Daily expo-
sures above threshold levels produced cumulative injury that progressed
from the primary leaves to subsequent trifoliate leaves. Although salinity
suppressed plant growth, it extended the tolerance threshold for duration
of ozone exposure and significantly reduced the injury by ozone. Ozone
decreased Ca, Mg, K, and N contents of the leaves, increased stem contents
of these elements, and had relatively little effect on root contents.
72-73:030-006
INTERACTIVE EFFECTS OF SALINITY AND OZONE ON GROWTH AND YIELD OF GARDER BEET,
Ogata, G. and Maas, E.V.
United States Department of Agriculture, Agricultural Research Service,
Salinity Laboratory, Riverside, California.
Journal of Environmental Quality, Vol 2, No 4, p 518-520, October-December,
1973. 2 tab, 12 ref.
Descriptors: *Air pollution, *Ozone, Salinity, Saline soils, Osmotic pressure,
Soil chemical properties, Salt tolerance.
The interactive effects of root media salinity and ambient ozone on injury
growth, and yield of garden beets were determined under controlled environ-
mental conditions. Plants were grown in nonsaline and saline nutrient
solution cultures having osmotic potentials of -0.4, -4.4, and -8.4 bars,
respectively, and were exposed 5 weeks to 0.20 ppm ozone for 0 to 3 hours/day.
Growth of the nonsaline beet plants were not significantly affected by 0.20
ppm ozone until exposure times exceeded 1 hour/day, although foliar injury
in the form of a reddish-purple stipple had developed on mature leaves.
Longer ozone exposures produced severe leaf necrosis and reduced the growth
of tops and storage and fibrous roots as much as 50, 40, and 67%, respectively.
In contrast, foliar ozone injury on plants grown in saline media developed
more slowly and the growth of both tops and roots were relatively unaffected
by ozone exposures of up to 3 hours/day. The beneficial effect of salinity
in reducing ozone damage was offset by the suppressive effect of salinity
on the yield of the storage root.
72-73:030-007
GROWTH, MINERAL COMPOSITION, AND SEED OIL OF SESAME AS AFFECTED BY NaCl,
Yousif, Y.H., Bingham, F.T., and Yermanos, D.M.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Soil Science Society of America Proceedings, Vol 36, No 3, p 450-453, May-June,
1972. 2 fig, 4 tab, 20 ref.
Descriptors: *Salinity, *Crop response, Sodium, Chlorides, Seeds, Sodium
chloride, Oilseed crops.
The tolerance of sesame to NaCl salinity was studied first during germination,
and later during plant growth up to maturity. Germination was conducted
in the laboratory at 25C. Sesame plants were tested for response to salinity
using nutrient solution cultures with sodium chloride added when test
plants were approximately 10 cm tall. Experiments were continues until
mature seed pod formation. The data showed a high tolerance during germination
but sensitivity at later growth stages.
72-73:03C-008
SALINITY, PLANT GROWTH, AND METABOLISM
Greenway, H.
Western Australia University, Nedlands. Department of Agronomy
Journal of the Australian Institute of Agricultural Science, Vol 39, No 1
p 24-34, March 1973. 6 fig, 2 diag., 3 tab, 61 ref.
Descriptors: *Salinity, *Plant growth, *Metabolism, Water utilization.
Agriculture, Arid climates, Semiarid climates, Saline water, Plant physiology,
174
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Plant breeding, Electrolytes, Water shortage, Irrigation, Salt tolerance.
Water use for agricultural purposes, in arid and semiarid climates, usually
implies the use of saline water. The challenge, then, is to increase the
physiological tolerance of plants to saline water. Steps to improve agri-
culture in saline areas include: assessing large numbers of plant species
for their response to salt; plant breeding for salt tolerance before further
selection for other characteristics; and the understanding of causes for
varietal differences in salt tolerance which for varietal differences in
salt tolerance which would provide the basis for methods of selection at
very early growth stages. Species should be evaluated in terms of causes
for growth stimulations and growth reductions with the organism as a whole
considered. Understanding how electrolytes and water deficits affect
metabolism, along with information on growth and development should be
the basis for further study in situations where either specific ion effects
or water deficits are indications of salt injury. Physiological research
should aim at the elucidation of the mechanisms of salt tolerance of
various species especially if irrigation agriculture continues on a world
wide scale. This research would further aid in understanding other bio-
logical issues, such as the physiology of marine organisms.
72-73:03C-009
SALINITY-OZONE INTERACTIVE EFFECTS ON YIELD AND WATER RELATIONS OF PINTO BEAN,
Hoffman, G.J., Maas, E.V., and Rawlins, S.L.
United States Department of Agriculture, Agricultural Research Service,
Salinity Laboratory, Riverside, California.
Journal of Environmental Quality, Vol 2, No 1, p 148-158, January-March, 1973
4 fig, 2 tab, 16 ref.
Descriptors: *Salinity, *Air pollution effects, *Air pollution, Plant
growth, Beans, Leaves, Ozone, Oxidation, Osmotic pressure, Water p llution
effects.
The interaction of salinity and ozone on the growth of pinto bean was evaluated
in a controlled temperature light room. Salinity treatments having osmotic
potentials of -0.4, -2.0, and -4.0 bars were studied in combination with
2-hour daily exposures to 0, 0.15, 0.25, and 0.35 ppm of ozone. Ozone
at 0.15 ppm decreased the yield of nonsaline plants nearly 50%; and at 0.25
ppm and higher, no significant yield was obtained. The results were essen-
tially the same for plants salinized to -2.0 bars. At -4.0 bars, the yield
was obtained. The results were essentially the same for plants salinized
to -2.0 bars. At -4.0 bars, the yield at 0.25 ppm was only reduced to
half that of the ozone-free treatment. The results indicate no intercation
between salinity and ozone below 0.15 ppm. Above 0.15 ppm, however, there
is a large interaction. At salinities of -0.4 and -2.0 bars, water-use
efficiency decreased as ozone increased. Ozone did not appear to influence
leaf water potential or its components.
175
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Section XV
WATER SUPPLY AUGMENTATION AND CONSERVATION
CONSERVATION IN DOMESTIC AND MUNICIPAL USE (Group 03D)
72-73:030-001
RETURN IRRIGATION WATER IN HAWAII,
Young, R.H.F., and Lao, C.
Water Resources Bulletin, Vol 9, No 3, p 538- , June 1973,
(See 72-73:058-088)
176
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Section XVI
WATER SUPPLY AUGMENTATION AND CONSERVATION
CONSERVATION IN INDUSTRY (Group 03E)
72-73:03E-001
CHEMICAL METHOD OF PREVENTING LOSS OF INDUSTRIAL AND FRESH WATERS FROM PONDS,
LAKES AND CANALS,
Rosene, R. V., and Parks, C. F.
Dow Chemical Company, Dowell Division.
Water Resources Bulletin, Vol. 9, No. 4, p 717-722, August, 1973. 2 fig,
5 ref.
Descriptors: *Seepage, ^Seepage control, *Sealants, Polymers, Water loss,
Groundwater, Impervious membranes, Leakage, Linings, Reservoir leakage, Soil
sealants.
Preventing or markedly reducing the loss of aqueous fluids from a variety of
reservoirs is becoming increasingly important. Fear of pollution from indust-
rial waters and sewage impoundments as well as the economic factors involved
in loss of fresh water add impact to this problem. This paper reviews the
seriousness of the problem and methods that have been used to reduce loss of
fluid are discussed. New materials for control of water loss are constantly
being advocated, and chemical research has provided new systems that work
extremely well. These systems, which combine unique chemicals and novel
methods of application, are described. Specific case histories are included.
177
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Section XVII
WATER SUPPLY AUGMENTATION AND CONSERVATION
CONSERVATION IN AGRICULTURE (Group 03F)
72-73:03F-001
SPRINKLING AND PONDING TECHNIQUES FOR RECLAMINING SALINE SOILS,
Oster, J.D., Willardson, L.S., and Hoffman, G.J.
Agricultural Research Service, Riverside, California.
Paper 72-210, 1972 Annual Meeting, American Society of Agricultural Engineers,
Hot Springs, Arkansas, June 1972. 7 p, 2 fig, 5 ref.
Descriptors: *Leaching, *Ponding, *Sprinkling, Soil conservation, Saline
soils, Soil properties, Salinity, Percolation, Infiltration, Soil water
movement. Rates of application, Efficiencies, On-site tests, California,
Evaporation, Electrical conductance, Soil profiles.
Identifiers: *Soil reclamation, *Land reclamation, Imperial Valley (CA),
Unsaturated flow, Field permeability tests. Sensors.
Reclaiming saline soil is usually accomplished by ponding for several months,
despite evidence that intermittent ponding and sprinkling are more efficient
in terms of water used. Salt displacement is most efficient under unsaturated
flow. Using sprinklers, the application rate must be less than the maximum
percolation rate to maintain unsaturated conditions. All experiment in the
Imperial Valley, California, compared continuous ponding, intermittent ponding,
and sprinkling techniques in 3 plots of 1150 sq m. Twelve salinity sensors
monitored leaching in each plot. Electrical conductivity was standardized at
25 deg C. Soil salinity for the sprinkler plot did not change for 25 days be-
cause of low application rate and lag in moisture movement. Salinity reductions
for all treatments was most rapid immediately after the first application for
continuous and intermittent ponding and during initial stages of downward
movement of water from sprinkling. Time required to reduce salinity by
half was the same for the 3 leaching techniques. In terms of water used,
intermittent ponding is most efficient, followed by sprinkling.
72-73:03F-002
SPRINKLER WATER DISTRIBUTION TESTING IN A DESERT ENVIRONMENT,
Hermsmeier, L.F.
Agricultural Research Service, Brawley, California. Imperial Valley Conserva-
tion Research Center.
Transactions of the ASAE, American Society of Agricultural Engineers, Vol 15,
No 3, p 436-439, May-June 1972. 7 fig, 2 tab, 9 ref.
Descriptors: *Sprinkler irrigation, *Distribution patterns, *Agricultural
engineering, *Analytical techniques, *Measurement,*Optimization, Arid lands.
Agriculture, Irrigation systems, Irrigation design. Irrigation practices,
Crop production. Water management (Applied), Farm management. Evaporation,
Salinity, Testing procedures, Data collections, Irrigation efficiency.
In recent years sprinkler irrigation has become more widely practiced in many
arid regions. In addition to providing water for crop growth, sprinklers are
being used to apply water for a variety of specialized purposes including ger-
mination, salt control, frost protection and fertilizer and insecticide
applications. Achieving uniform distribution, however, is particularly diffi-
cult with low application rate sprinklers because of their sensitivity to pres-
sure, nozzle size, and spacing variables. A test facility for determining
distribution patterns, evaporation losses and salt content changes of water
for sprinkler irrigation has been constructed at the Imperial Valley Conser-
vation Research Center, Brawley, California. Water from test sprinklers is
caught in a series of catcher assemblies placed at 5-ft intervals in a square
grid pattern. The test area size is 100 by 100 feet. Water for the system
is supplied by a domestic water system, and uniform pressure is maintained with
a booster pump and pressure regulator. Water is measured with a standard water
meter. Windspeed and direction, air temperature, water temperature, and
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relative humidity are also measured. Sprinkler distribution patterns can
be determined by one man in one-half hour plus sprinkler operation time with
this system. Data collection is in the form of photographs which provide a
visual representation of the distribution pattern and from which the amount
of water on 0.01-in depth increments received at 50 feet square grid intervals
in a 100-feet test area can be determined. The increase in time of operation
for any given percentage of the field to receive a designed amount of irri-
gation water can be readily determined for any test condition.
72-73:03F-003
CENTER-PIVOT SPRINKLER DESIGN BASED ON INTAKE CHARACTERISTICS,
Dillon, R.C., Jr., Hiler, E.A., and Vittetoe, G.
Texas ASM University, College Station; and Soil Conservation Service, Temple,
Texas.
Paper 71-759, American Society of Agricultural Engineers, 1971 Winter Meeting,
Chicago, Illinois, December 1971. 27 p, 9 fig, 6 tab, 8 ref.
Descriptors: *Sprinkler irrigation, *Surface runoff, *Irrigation design,
*Absorption, Design, Design criteria, Soil-water relationship, Water distri-
bution (Applied), Water utilization, Irrigation efficiency, Root zone, Irrigated
land, Characteristics, Crops, Rotation, Surface storage, Soil types, Slopes,
Velocity, Irrigation.
Identifiers: *Water application rate, Soil storage capacities, Water retention,
Soil-water relationship.
A procedure is developed enabling an engineer to design a center-pivot
sprinkler irrigation system that will meet crop requirements without surface
runoff. Equations are derived and design curves presented for determining
peak water use, speed of travel, time per revolution, depth of application,
discharge from water source, and length of the system. The procedure
matches a system to a particular soil by determining the minimum speed of
travel from the soil intake characteristics and the allowable surface storage.
Potential runoff from the soil occurs when the allowable surface storage of
the soil is satisfied. Values for the allowable surface storage for various
slopes are given. Numerical values are given in the tables for: (1) peak water-
use rates for various crops, (2) irrigation efficiencies for various crops
and climates, (3) feeder root depth of different crops, (4) soil storage
capacity for different soils, and (5) sprinkler intake equations for different
soils. This procedure is exemplified for a 180-acre square field.
72-73:03F-004
IRRIGATION PLANNING, 3. THE BEST SIZE OF IRRIGATION AREA FOR A RESERVOIR,
Dudley, J., Musgrave, W.F., Howell, T.
Montana State University, Bozeman. Department of Economics and Agricultural
Economics.
Water Resources Research, Vol 8, No 1, p 7-17, February 1972. 5 fig, 3 tab,
3 ref.
Descriptors: *Simulation analysis, *Irrigation programs, *Irrigation systems,
^Decision making, *Reservoirs, *Stochastic processes, *Water supply, *Water
demand, *Fixed costs, *Model studies, Costs, Systems analysis, Long-term
planning.
Identifiers: Corn
A simulation model was used to determine the best-sized area to develop for
irrigation in conjunction with a given dam. The model was applied to a hypo-
thetical situation involving the irrigation of a single crop, corn. It was
assumed that releases from the given reservoir, the acreage to be planted, and
irrigation timing were all controlled by one decision maker. Short-run models
were used to estimate the best area to plant and the best way to allocate a
quantity of water given a stochastic demand and supply. The results of the
short-run models were incorporated into the long-run simulation model. The
solutions of the simulation model were highly sensitive to changes in total
fixed costs. The costs of applying the model are likely to be much less than
the penalty of choosing suboptimal acreages. The models are capable of
being elaborated to assist decision making in more complex systems that con-
sidered in this paper.
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72-73:03F-005
ONE APPROACH TO IRRIGATION MODELING UNDER RISK,
Smith, D.V.
Harvard University, Cambridge, Massachusettes, Center for Population Studies.
Water Resources Bulletin, Vol 8, No 6, p 1225-1234, December 1972. 46 equ,
21 ref.
Descriptors: *Irrigation, *Planning, *Water supply, *Stochastic processes,
*Linear programming, Optimization, Water demand, Water balance, Wells,
Canals, Rainfall, Streamflow, Mathematical models, Systems analysis.
Identifiers: *Uncertainty, *Water deficits, *Risk levels, Cropping patterns,
Chance-constrained programming.
To demonstrate the strengths and weaknesses of stochastic programming with
recourse, a problem in irrigation planning is considered. It is based upon
a deterministic planning model and a series of stochastic planning models
that build upon a project area water balance, to evaluate the irrigated area
to be developed, the cropping pattern to be selected, and the required capa-
cities of the well and canal systems; it is assumed that there is no surface
reservoir storage of water. Stochastic programming with recourse is shown to
have considerable potential for modeling a complex irrigation problem under
conditions of random rainfall and streamflow. Its utility will grow as
computational techniques are improved for solving multistage stochastic
programming with recourse problems, and as agronomists provide the
necessary loss functions for water deficits.
72-73:03F-006
IRRIGATION PLANNING 4, OPTIMAL INTERSEASONAL WATER ALLOCATION,
Dudley, N.J.
Montana State University, Bozeman Department of Economics; and Montana State
University, Bozeman. Department of Agricultural Economics.
Water Resources Research, Vol 8, No 3, p 586-594, June 1972. 4 tab, 4 ref.
Descriptors: *Irrigation engineering, *Irrigation operation and maintenance,
*Acreage, *Irrigation water, *Water transfer, *Water supply, Water demand,
Water consumption, Reservoirs, Seasonal, Dynamic programming, Simulation
analysis, Optimization, Estimating, Benefits, Net profit, Decision making.
Systems analysis, Soil moisture, *Model studies.
Identifiers: *Reservoir water, *Interseasonal transfer, *Interseasonal water
allocation, Computer output.
A series of models has been developed in previous papers to estimate the best
sized area to develop for irrigation from a given reservoir under conditions
of variable supply and demand for irrigation water. The most economically
feasible operating policies for such a system were also derived. The previous
approach is extended by recognizing the value of water carried over from one
season to the next. A modified version of the previous approach is used to
generate reservoir level transition probabilities and expected benefits.
A dynamic programming model is then used to estimate the expected benefits from
allocating water optimally between seasons. These expected benefits are a
function of acreage developed for irrigation and beginning-season reservoir
levels. Such a function allows a decision maker at any decision point within
an irrigation season to equate the expected net benefits from allocating water
to the rest of the current season with the expected net benefits from saving
such water for the following season. This decision-making process is simu-
lated for a number of seasons. The results of an application of the
models indicate that such interseasonal transfer can considerably increase
the present value of expected benefits from the project.
72-73:03F-007
OPTIMAL IRRIGATION QUANTITY AND FREQUENCY,
Wu, Ipai and Liang, T.
Hawaii University, Honolulu Department of Agricultural Engineering.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol 98, No IR1, Paper 8776, p 117-133, March 1972. 10 fig, 4 tab,
2 ref.
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Descriptors: *Optimization, *Irrigation practices, *0perations research,
Mathematical models, Cost analysis, Soil moisture, Vegetable crops, Evapo-
transpiration, Tensiometers, Rots, Field capacity, Lettuce, Hawaii, *Irrigation
efficiency, *Crop production.
Identifiers: Celery
Mathematical models are derived to aid in selecting optimal soil moisture
levels for maximum crop yield in irrigation farming. Minimum irrigation cost
over the entire growth period is selected as the principal criterion for
determining optimal irrigation practices. Optimal irrigation frequency and
quantity needs vary between different crops. Evaluation of the models indi-
cates that these specific needs'can be determined when irrigation costs and
average consumptive use are known. Major irrigation cost consists of the
expense in purchasing and delivering water and the economic losses caused
by crops grown under unfavorable soil moisture conditions. The models are
based upon two different irrigation practices: (1) Soil moisture kept equal
or below the optimal soil moisture and (2) Soil moisture allowed to fluctuate
above or below the optimal soil moisture. A technique for assessing optimal
soil moisture, crop yield and cost functions is further developed from irri-
gation experiments in Hawaii with lettuce and celery. Results show that
lettuce produces its maximum yield at soil moisture less than field capacity
This demonstrates that general irrigation practices, irrigating to field
capacity, is not always the optimal irrigation schedule.
72-73:03F-008
PREDICTION OF IRRIGATION ADVANCE FUNCTION BY DIMENSIONAL ANALYSIS,
Sastry, G., and Agarwal, S.C.
Indian Institution of Tech., Kharagpur, Department of Agricultural Engineering.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Proceedings, Vol 98, No IR2, p 247-253, June 1972. 2 fig, 12 ref.
Descriptors: *Irrigation, *Dimensional analysis, *Computers, *Field capacity,
Mathematical studies, Hydraulic conductivity, Forecasting, Inflow, Soil types,
Infiltration, Soil water movement.
One of the important factors in the design of a surface irrigation system is
the prediction of the advance distance-time relationship when estimating in
advance for a given entrance stream size and land surface slope under given
soil bed infiltration characteristics variation. An attempt has been made
to derive an advance equation by dimensional analysis of the fundamental
variables involved in water advance phenomena. Dominant variables considered
include distance of advance, elapsed time, inflow stream per unit top width of
flow, slope of soil bed, acceleration due to gravity, exponent in the
in the Kostiakov type accumulated infiltration function, hydraulic conductivity
of soil bed and absolute roughness of the bed. With available field data,
the derived equation was tested and found satisfactory. Using the proposed
technique, a general equation can be derived with suitable experimentation.
72-73:03F-009
ATTAINABLE IRRIGATION EFFICIENCES,
Willardson, L.S.
Agricultural Research Service, Brawley, California. Imperial Valley Conser-
vation Research Center.
Journal of Irrigation and Drainage Division, American Society of Civil Engineers,
Vol 98, No IR2, p 239-246, June 1972. 1 fig, 2 tab, 15 ref.
Descriptors: *irrigation efficiency, *Root zone, *Uniformity coefficient,
Irrigation systems, Economic feasibility, Political aspects, Infiltration
rates. Soil water movement. Sprinkler irrigation.
Identifiers: *Trickle irrigation
The general objective of irrigation is to provide a suitable moisture environ-
ment in the soil for plant growth. Since water supplies for irrigation in the
arid and semiarid western U.S. have never been as plentiful as irrigators would
like, the concept of irrigation efficiency has received much attention. Irri-
gation efficiency is considered equivalent to water application efficiency or
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72-73:03F-010
WATER DEFICITS-IRRIGATION DESIGN AND PROGRAMMING,
Hagan, R.M., and Stewart, J.I.
California University, Davis, Department of Water Science and Engineering.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol 98, No IR2, p 215-237, June 1972. 2 fig, 2 tab, 124 ref.
Descriptors: *Irrigation practices, *Evapotranspiration, *Planning, *Peak
loads, *Irrigation programs. Soil moisture. Soil-water plant relationships,
Moisture tension. Moisture deficit, Productivity, Economic feasibility,
Crop response.
Identifiers: *Water use efficiency, *Production functions, *Plant water
potential.
Irrigation systems are created with the intention of providing water to crops
to prevent the occurrence of crop water deficits that will lead to uneconomic
yields. Design engineers must deal with the problem of matching the capacities
of water distribution and water application to the peak use rates indicated
by the peak evaporation rates. Water use efficiency is a prime goal because
building increased capacity into distribution and application systems is
very expensive. Economic information is needed on the expected effects of
water deficits on crop yields, which is unfortunately scarce. Two approaches
to irrigation programming and design of irrigation system peak capacities to
meet delivery and application requirements are presented. The first is a
comprehensive tabulation of available data on allowable soil water suction.
This updates and adds to earlier information. Much of the data shows consid-
erable scatter and it is obvious that plant water deficits would be better
described by plant water potential rather than soil moisture. The conditions
of evaporative demand complicate any interpretation of soil moisture in
terms of plant moisture stress. The second approach is a continuing research
program on preseason irrigation programming techniques and development of
water production functions for principal crops, relating yield reductions to
water deficits. These functions will vary with type of crop, soil depth and
water holding capacity. Evaporative demand of the area in question, and
with the particular program adopted for times and depths of water applications.
72-73:03F-011
DISTRIBUTION CHANNELS WITH MULTIPLE OUTLETS,
Hart, W.E., and Borrelli, J.
Colorado State University, Fort Collins, Department of Agricultural
Engineering; and Pennsylvania State University, University Park, Department
of Civil Engineering.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol 98, No IR2, p 267-274, June 1972. 2 fig, 1 tab, 8 ref.
Descriptors: *Semiarid climates, *Distribution systems, *Channels, *Irrigation
systems. Spillways, Furrow irrigation. Ditches, Economic feasibility, Cali-
fornia, Outlets, Hydraulic structures. Slopes.
Land use improvements in California require agricultural intensification in
some portion of the state's approximate 8 million acres of rolling dry foot-
hills. An obvious first step would be irrigated pasturelands, but the eco-
nomics of such land development dictate an irrigation system with low labor,
capital and water requirements. The practical solution to these requirements
is a graded supply ditch in which the water is checked at intervals to form
bays. When a given bay is checked, the total supply flow is diverted through
multiple, equally spaced outlets into field corrucations. The corrugation
system is designed to allow simultaneous discharge from several identical out-
lets equally spaced along a graded open supply ditch. Design procedures for
the bays and outlets under a wide set of field conditions are outlined.
In order to insure approximately equal outflow from each of the several
operating outlets, it is necessary that the head on all outlets be nearly
equal. The required minimum head can be estimated using the gradually and
rapidly varied flow equations. The design of zero-slope channels is also
discussed.
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72-73:03F-012
IRRIGATION THROUGH SUBSURFACE DRAINS,
Skaggs, R.W., Kriz, G.J., and Bernal, R.
North Carolina State University, Raleigh
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers; Vol 98, No IR3, p 363-373, September 1972. 8 fig, 11 ref, append.
Descriptors: *Subsurface irrigation, *Theoretical analysis, On-site inves-
tigations, Hydraulic conductivity, Subsurface drains, Groundwater movement,
Permeability, Irrigation systems, Evapotranspiration, Soil water movement,
Drainage effects, Steady flow. North Carolina, Impervious soils, Water table,
Irrigation, Loam.
Identifiers: *Drain spacing, Sandy loams, Tile spacing.
Subirrigation aims at raising and maintaining the water table to a level
sufficient to supply the water needs of a crop. Management of the water
table is dependent upon: (1) an impermeable layer or a permanent water table
at shallow depth to minimize seepage losses; (2) topography nearly flat so
that the supply is uniformly available in a field; and (3) soil having
a high hydraulic conductivity. Feasibility of subirrigation was investigated
on 12 tile lines 12.5 cm in diameter, in sets of 4, with 7.5 m, 15 m, and
30 m spacings. The soil was 20-30 cm of sandy loam underlain by a tight clay
layer. Results showed that water could be supplied successfully for all
but the 30 m spacing. Theory showed that a water table 30 cm above the tile
could be maintained midway between lines with a spacing of 19.2 m. An equa-
tion was derived for upward movement of the water table during the early
stages of subirrigation. Comparisons with field tests showed the equation
to be accurate for predicting the rise midway between tile lines.
72-73:03F-013
IRRIGATION MANAGEMENTA TOOL FOR AGRIBUSINESS,
Schild, N.W., and Nelson, Jr., H.R.
Bureau of Reclamation, Denver, Colorado. Water Operations Branch.
Journal of the Irrigation and Drainage Division, American Society of
Civil Engineers, Vol 98, No IRS, Paper 9211, p 347-361, September 1972.
7 fig, 3 tab, 10 ref.
Descriptors: Irrigation operation and maintenance, *Irrigation efficiency,
*Management, *Computers, Agricultural engineering, Soil moisture, Water
distribution (Applied), Reclamation, Water resources, Crops, Optimum develop-
ment plans.
Identifiers: *Agribusiness, *Jensen-Haise method, *Climatic parameters, Crop
consumptive use.
Irrigation Management is a tool whereby timely application of water can
improve irrigation efficiencies. Irrigation Management has been made possible
by adaptation of a computer program to the Jensen-Haise method of computing
crop consumptive use. A daily soil moisture level balance is available by
inserting climatic parameters for a computer printout at a specific time.
These printouts are presented to irrigators who can be shown when the next
irrigation application will be required for a specific field. This will improve
irrigation efficiencies because the water will be applied when the soil
moisture level is deficient. Data previously collected indicated that irri-
gators were unaware of soil moisture levels when applying water. Irrigation
Management Services being conducted by Bureau of Reclamation personnel in
Kansas and Wyoming are presented. Data for the Irrigation Management have
been analyzed showing results during 1971. The future of Irrigation Manage-
ment is exploited and incorporated with operation of irrigation systems.
72-73:03F-014
PLANNING AND UPDATING FARM IRRIGATION SCHEDULES,
Buras, N., and Pistun, A.M.
Technion - Israel Institution of Technology, Haifa. Lowdermilk Faculty of
Agricultural Engineering . ,
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol 99, No IR1, Proceedings paper 9586, p 43-51, March, 1973. 5
fig, 8 ref, 2 append.
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Descriptors: *Irrigation, Irrigation engineering, *Irrigation programs,
*Scheduling, *Management, Simulation analysis. Digital computers, Optimum
development plans, Water resources, Soil moisture, Agriculture, Crops, Farms,
Water supply, Distribution, Networks, Planning, Climatic data, Hydraulics
Systems analysis. Mathematical models.
The optimal scheduling of irrigation activities is a considerably complex
problem, requiring a large computational effort. Digital computers are useful
in the planning process. 'A computer program is developed for the planning
of irrigation schedules within the broader context of agricultural production,
and for the updating of these schedules whenever necessary. The computer
program, which is oriented toward solving problems arising during the busy
irrigation season, is a simulation algorithm which schedules the application
of water on the basis of soil moisture balances at given intervals of time.
The irrigation requirements are then checked against the hydraulic character-
istics of the farm water distribution system. Delays in replenishing the
moisture deficiency within the root zone generate losses which are functions
of the magnitude of the delay and of the vegetative status of the crop. The
alternative schedule which minimized these losses is selected. The program
has the advantage that it allows the planning of farm irrigation schedules
to progress in stages; as current information regarding climatic and soil
conditions, water supply, agrotechnical practices, and marker conditions
becomes available, the initial schedule can be quickly updated so as to reflect
the changing environmental conditions.
72-73-.03F-015
SOIL NITROGEN BALANCE IN SELECTED ROW-CROP SITES IN SOUTHERN CALIFORNIA,
Adriano, D.C., Takatori, F.H., Pratt, P.P., and Lorenz, O.A.
California University, Riverside, Department of Soil Science.
J Environmental Quality, Vol 1, No 3, p 279-283, 1972. Illus.
Identifiers: California, Crops;SLtes, Denitrification, Drainage, *Fertili-
zation, Irrigation, Nitrate, *Nitrogen, Soils, Row crops.
Nine row-crop sites, where data for N fertilizer use, crop yields, and amounts
of irrigation water used were available for a number of years, were studied
to estimate the N balance as related to No-3 in water in the unsaturated zone
from below the zone of root influence to the water table or to the 15-m
depth. The system of predicting NO3-concentrations in drainage waters based
on the difference between N inputs and N removal in harvested crops and the
drainage volume in which the excess N, converted to N03-, is dissolved,
was valid in open-porous soils containing no layers that restrict water move-
ment within the soil profile (0 to 2-m depth). A combination of losses
plus net immobilization of up to 56% had to be assumed in some soils to account
for all the N loss. In 2 soils that had been used for disposal of feedlot
manure, net mineralization of N from the organic N pool had to be assumed to
explain the data obtained. The current fertilization and irrigation practices
used for some row crops in southern California leave varying amounts of
N03- in the drainage water. The amounts depend on the total N added, crop
removal, drainage volume, net mineralization and losses.
72-73:03F-016
CONSTRAINTS IN WATER MANAGEMENT ON AGRICULTURAL LANDS,
Radosevich, G.E., Vlachos, E.G., and Skogerboe, G.V.
Colorado State University, Fort Collins. Department of Economics.
Water Resources Bulletin, Vol 9, No 2, p 352-359, April 1973.
Descriptors: *Water management (Applied), *Irrigation, *Administration,
*Social aspects, *Water law, *Water policy, Irrigation practices. Irrigation
districts, Social values, Return flow, Water rights, Water quality
control, Constraints.
Whether the goal is minimizing water quality degradation in receiving streams
of maximizing agricultural production on existing croplands, the solutions are
identicalimproved water management practices. Technology has succeeded
in developing feasible solutions to improvement of irrigation water manage-
ment, but the law has been slow to direct or encourage implementation. The
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culprit of the western United States water problem is the property right con-
cept of the appropriation doctrine. The most substantial impact in solving
the legal and other institutional constraints inherent in the appropriation
doctrine would be more stringent application of the beneficial use concept.
Moreover, water quality should be made a part of each water right, the appur-
tenancy concept, which ties water to land, should be eliminated, and water
laws should be modified to encourage the renting, leasing, transferring or
selling of water rights to other uses and places so long as the vested rights
of others are protected. Improving water management also implies organiza-
tional improvements such as increasing project irrigation efficiency and
effectiveness through consolidation of fragmented irrigation and drainage
districts into valley-wide single management units. All attempts for modifying
water use must be guided by a pervasive spirit of social consciousness.
72-73:03F-017
SYSTEMS ANALYSIS AND IRRIGATION PLANNING,
Smith, O.V.
Harvard University, Cambridge, Massachusettes, Center for Population Studies.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol 99, No IR1, Proceedings paper 9625, p 89-107, March, 1973.
2 fig, 2 tab, 64 ref.
Descriptors: *Irrigation, *Irrigation programs, *Project planning, *Systems
analysis, Optimization, Linear programming, Stochastic processes, Economic
analysis, Agriculture, Groundwater, Water resources, Mathematical models,
Hydrology, Dynamic programming.
Identifiers: Deterministic models.
Certain concepts and techniques of systems analysis can aid irrigation planning
in poor countries that have social and physical environments radically different
from those found in industrialized nations with extensive irrigation practice.
An ample literature survey is followed by description of the basic determinis-
tic planning model, a model emphasizing the interactive consequences of
cropping pattern selection, conjunctive use of ground and surface water, and
employment of wells as water table control devices. Stochastic parameters
are introduced into the model to improve its representation of reality
and to interpret meaningfully the consequences for stochastic variability.
Various factors favor the use of the chance-constrained approach to stochastic
programming. Unlike previous applications, general distribution functions,
variable capacities, piecewise linear decision rules, and stochastic demands
and supplies are dealt with.
72-73:03F-018
SYSTEMS ANALYSIS IN IRRIGATION AND DRAINAGE,
Hall, W.A.
Cwlifornia University, Riverside, Dry-Lands Research Institution.
Journal of the Hydraulics Division American Society of Civil Engineers,
Vol 99, No HY4, Proceedings paper 9659, p 567-571, April 1973. 5 p.
Descriptors: Irrigation, *Drainage, *Systems analysis, *Soil moisture,
Water resources, Decision making. Foods, Crops, Hydraulics, Agriculture,
Plants, Nutrients, Optimization, Streamflow, Risks, Alternative planning,
Mathematical models, Water rights, Water demand, Water costs, Water shortage,
Salinity, Droughts, Irrigation water.
It is imperative that water engineers and planners utilize systems in order
that costly irreversible water decisions may be based upon sound judgments.
Growing population, problems of inadequate nutrition, and rising standards
of living all demand increases in food production. The rate of increasing
agricultural productivity cannot be maintained by continued use of fertilizer,
pest control, and genetics; only irrigation and its correlative drainage can
be counted on for certain to increase food and fibre supplies. But water
shortages and resulting high costs pose great difficulties. Because of such
food production and water cost squeezes, and a serious political squeeze
wherein potential water for agriculture is given to cities, irrigation and
drainage must be brought to a point of maximum efficiency. Needed is a new
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technology for agricultural water use based on systems analysis, for: (1)
precision control of soil moisture related factors of production; (2) opti-
mization of the use of unregulated stochastic streamflows; (3) optimization
of risk and return from water use under uncertainty; and (4) optimal salinity
and drought strategies. This step must be taken, regardless of important
analytical limitations and considerable additional fundamental research
requirements.
72-73:03F-019
SPRINKLING AND PONDING TECHNIQUES FOR RECLAIMING SALINE SOILS,
Oster, J.D., Willardson, L.S., and Hoffman, G.J.
Agricultural Research Service, Riverside, California.
Paper 72-210, 1972 Annual Meeting, American Society of Agricultural Engineers,
Hot Springs, Arkansas, June 1972. 7 p, 2 fig, 1 tab, 5 ref.
Descriptors: *Leaching, *Ponding, *Sprinkling, Soil conservation, Saline
soils, Soil properties. Salinity, Percolation, Infiltration, Soil water move-
ment. Rates of application, Efficiencies, On-site tests, California, Evapora-
tion, Electrical conductance, Soil profiles.
Identifiers: *Soil reclamation, *Land reclamation, Imperial Valley (CA),
Unsaturated flow, Field permeability tests. Sensors.
Reclaiming saline soil is usually accomplished by ponding for several months,
despite evidence that intermittent ponding and sprinkling are more efficient
in terms of water used. Salt displacement is most efficient under unsaturated
flow. Using sprinklers, the application rate must be less than the maximum
percolation rate to maintain unsaturated conditions. An experiment in the
Imperial Valley, California, compared continuous ponding, intermittent ponding,
and sprinkling techniques in 3 plots of 1150 sq m. Twelve salinity sensors
monitored leaching in each plot at depths of 53 cm and 86 cm at 3 positions
on the centerline of each plot. Electrical conductivity was standardized
at 25 deg C. Soil salinity for the sprinkler plot dit not change for 25
days because of low application rate and lag in moisture movement. Salinity
reduction for all treatments was most-rapid immediately after the first appli-
cation for continuous and intermittent ponding and during initial stages of
downward movement of water from sprinkling. Time required to reduce salinity
by half was the same for the 3 leaching techniques. In terms of water used,
intermittent ponding is most efficient, followed by sprinkling.
72-73:03F-020
WHEAT RESPONSE TO SOIL MOISTURE AND THE OPTIMAL IRRIGATION POLICY UNDER
CONDITIONS OF UNSTABLE RAINFALL,
Yaron, D., Strateener, G., Shimshi, D., and Weisbrod, M.
Hebrew University, Jerusalem (Israel)
Water Resources Research, Vol 9, No 5, p 1145-1154, October 1973. 2 fig, 6
tab, 17 ref.
Descriptors: Irrigation efficiency, *Soil moisture, *Rainfall, *Stochastic
processes, *Simulation analysis, *Decision making, *0ptimum development plans,
Computer models, Estimating, Irrigation practices, Crops, Water management
(Applied), Systems analysis, Risks.
Identifiers: *Wheat yield, Irrigation policy.
Presented is a method for estimating a response function of wheat yield to
soil moisture and for determining the optimal irrigation policy under con-
ditions of stochastic rainfall. To determine such policy, information on
the variation of the soil moisture over time as a function of depth is needed.
A low-cost, computer simulation, soil moisture estimation model designed
to reconstruct the soil moisture fluctuations (during the growing season of
wheat) on the basis of incomplete data is described. Then, empirical esti-
mates of the response function of wheat yield derived on the basis of a four-
year irrigation experiment are presented; use is made of the Mitscherlich
function. For the problem of deriving the optimal irrigation policy under
conditions similar to those in the experiment (unstable rainfall), the soil
moisture estimation model and the estimate of the Mitscherlich response func-
tions have been applied in an analysis in which the rainfall record
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representing the random rainfall distribution at the experiment site for a
period of 16 years is taken into account. Two approaches are compared by
simulating their consequences in relation to the 16-year rainfall record.
72-73:03F-021
STOCHASTIC RESERVOIR MANAGEMENT AND SYSTEM DESIGN FOR IRRIGATION,
Dudley, N.J. and Burt, O.R.
New South Wales University, Kensington (Australia). School of Economics.
Water Resources Research, Vol 9, No 3, p 507-522, June. 1973. 3 fig, 22 ref.
Identifiers: Design variables, Interseasonal, Intraseasonal, Inte
Water application rates, Reservoir capacity, Distribution systems.
An integrated intraseasonal and interseasonal stochastic dynamic programming
model is developed to determine an optimal decision rule with respect to
the following classes of crop irrigation decisions: (1) intertemporal water
application rates (2) whether or not some acreage should be relinquished from
further irrigations for the remainder of the season; and (3) the optimal
acreage to plant for potential irrigation at the beginning of the season.
Solutions of the problem are shown to be a basis for optimizing the levels
of three design variables: Developed irrigation acreage, reservoir
capacity, and distribution system capacity. A method is presented for
incorporating variance, as well as expected value, of the net benefits into
the decision criterion for optimal developed acreage. An application is made
to a simplified real situation in which optimal acreage to develop is the
only design variable. State variable transition probabilities are calculated
by a simulation model. A significant trade-off is found between expected
net benefits and their variability in determination of the optimal developed
acreage for irrigation.
72-73:03F-022
EFFECT OF IRRIGATION, HARVEST INTERVAL, AND NITROGEN ON THE YIELD AND NUTRIENT
COMPOSITION OF NAPIERGRASS,
Capiel, M, and Ashcroft, G.L.
Puerto Rico University, Mayaguez. Agricultural Experiment Station.
Agronomy J. Vol 64, No 3, p 396-398, 1971
Studies were conducted in a subhumid area of Puerto Rico to investigate the
main effect and the interrelations of harvest interval, irrigation, and N
fertilization on the yield and nutrient composition of napiergrass. Harvest
interval exerted the main effect on the dry matter yield of the forage. N
fertilization and irrigation also had highly significant effects. Irrigation
interacted significantly with harvest interval to influence forage yield.
The increase in yield as a result of a longer harvest interval was nearly 92%
greater on irrigated than on nonirrigated plots. N fertilization produced a
highly significant increase in the protein yield of this forage. No other
management treatment appreciably influenced protein yields. Significant
negative correlations were obtained between yield and both N and K composi-
tion for the forage on the frequently harvested, irrigated plots. Both
nutrients were at lower concentration in the forage produced in harvest periods
that had high yields.
72-73:03F-023
PATTERNS OF WATER UPTAKE AND ROOT DISTRIBUTION OF SOYBEANS IN THE PRESENCE
OF A WATER TABLE,
Reicosky, D.C., Millington, R.J., Klute, A., and Peters, D.B.
Agricultural Research Service, Urbana, Illinois. Soil and Water Conservation
Research Division.
Agronomy Journal, Vol 64, No 3, p 292-297, May-June 1972. 7 fig, 2 tab, 13 ref.
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Descriptors: *Moisture uptake, Root systems, *Root distribution, *Absorption,
Soil-water-plant relationships, *Capillary fringe, *Soil water movement,
*Hydraulic conductivity, Water table, Crop production, Movement, Soil water,
Soils. Limiting factors, Plant growth, Plant physiology, Plant morphology.
Soil science, Soil tests, Fringe water, *Soybeans.
The increasing importance of water use in crop production has demonstrated
the need for integrated studies of water transport phenomena in the soil-
plant-atmosphere system. A better understanding of the basic principles
involved can lead to better management techniques for efficient water use.
The purpose was to measure water uptake patterns of soybeans and relate these
to root distribution and water uptake per unit root length. Water uptake in
soil columns was analyzed using the flow equations for water movement in the
soil, treating the root system as a macroscopic sink. Results indicate that
in the presence of a water table, water uptake was not necessarily related to
root distribution and that a small amount of roots near the capillary fringe
absorbed most of the water. Results also showed the combined importance
and interaction of the hydraulic conductivity and the root distribution in
determining the magnitude and the distribution of the sink term. Both of
these factors limited the rate of uptake. As the plants grew, both increased
water uptake per unit root length and increase in the length of roots contri-
buted to meeting the rising daily rate of water use.
72-73:03F-024
REFLECTED RADIATION FROM A SOYBEAN CROP,
Blad, B.L. and Baker, D.G.
Nebraska University, Lincoln. Department of Horticulture and Forestry.
Agronomy J. Vol 64, No 3, p 277-280, 1972 Illustration.
Identifiers: *Solar radiation, Albedo, Crops, Eppley, Glycine max D, Lodging,
Moisture, Pyranometer, Radiation, Soils, *Soybeans.
The albedo, defined as the percentage of incoming solar radiation that is
reflected, was measured continuously over a soybean crop (Glycine max. (L.)
Merr.) during the 1968, 1969, and 1970 growing seasons at St. Paul, Minnesota.
The study was undertaken to establish average albedo values for soybeans and
to evaluate the effects of increasing crop cover on the albedo. The average
daily albedo ranged from 24%-27% with complete soybean cover. The albedo of
the moist soil was approximately 10.5% with no cover and increase in crop cover.
Because this relationship held true over the entire growing season, it should
be possible to accurately estimate soybean cover from albedo measurements once
the growth characteristics of a variety have been established. It was also
possible during the study to examine the effects of soil moisture and lodging
on the soybean albedo. With full cover the albedo decreased at low soil moi-
sture because the soybean leaves wilted and became more vertically oriented,
thereby permitting increased penetration of incoming solar radiation. Before
canopy closure, particularly early in the season, low soil surface moisture
caused a marked increase in albedo. Severe lodging during mid-Aug. 1970 caused
a marked deereasein albedo. Failure to properly shield the inverted Eppley
pyranometer was shown to cause an increase in the daily average albedo of as
much as 7.5% because of internal reflection from the pyranometer dome. An
average albedo of 25.9% was obtained for 2 clear days. It was noted on
these days that morning albedoes were higher than evening albedoes at the
same solar altitudes. This was attributed to temporarily wilted, drooping
leaves, and to increased leaf flutter from stronger afternoon winds. The
average daily albedo for 2 cloudy days was 24%.
72-73:03F-025
INFLUENCE OF THREE CUTTING SYSTEMS ON THE YIELD, WATER USE EFFICIENCY, AND
FORAGE QUALITY OF SALINFOIN,
Koch, D.W., Dotzenko, A.D., and Hinze, G.O.
Colorado State University, Fort Collins, Department of Agronomy.
Agronomy Journal, Vol 64, No 4, p 463-467, July-August 1972. 2 fig, 6 tab.
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Descriptors: *Crop production, *Water utilization, Consumptive use, *Forage
grasses, *Legumes, Efficiencies, Evapotranspiration, Drought resistance, Diges-
tion, Colorado, Semiarid climates, Great Plains, Mature growth stage. Alfalfa,
Proteins, Cattle, Plant growth regulators, Rainfall, Temperature, Wind velocity,
Evaporation, Dry farming, Moisture stress, Calcium, Magnessium, Leaves, Cellu-
lose, Linings, Potassium.
Identifiers: *Sainfoin, *Cutting systems, Dry matter, Perennial grasses,
Maturation, Stems, Hemicellulose, Cell wall constituents.
Though few perennial legumes are well adapted to the semiarid environmental
conditions in the Central Great Plains, Sainfoin is one that compares well with
alfalfa productivity, and contains similar available energy to meet protein
requirements of beef animals. Sainfoin is a nonbloating, fairly drought-
tolerant forage. Yield, water-use efficiency and forage quality are reported
of sainfoin grown under climatic conditions that are typically semiarid and
characterized by erratic rainfall, extremes in temperature, high average wind
velocity, and high evaporation rates. Field experiments were performed at the
Central Great Plains Field Station at Akron, Colorado, to determine the poten-
tial of Sainfoin as a dryland forage crop. Despite below-average rainfall,
yields were 3,494 and 2,383 Kg/ha dry matter for 1969 and 1970, mostly produced
by the first cutting. Water-use efficiency was high for the first, but low for
the second cutting due to slow regrowth. Roots extracted soil moisture from
180 cm under lateseason moisture stress due to prolonged drought. Survival
rate over the 2-year period was lower for plants harvested consistently at the
early bloom stage. Leaf, protein, and mineral percentages, cell wall components,
and in vetro dry matter digestibility decreased little during maturing because
of high retention of leaves and rapid maturation. Leaves had high percentages
of protein, in vitro digestibility, Ca and Mg, and had lower percentages of
cellulose, hemicellulose, lignin, cell wall constituents and K than stems.
Sainfoin is an efficient water user and can survive moisture stress adequately.
72-73:03F-026
INFLUENCE OF LEVELS OF SPRING IRRIGATION AND FERTILITY ON YIELD OF WINTER WHEAT
(TRITICUM AESTIVUM L) UNDER SEMI-ARID CONDITIONS.
Poostchi, I., Rovhani, I., and Razmi, K.
Pahlavi University, Shiraz (Iran), Department of Crop Science.
Agronomy Journal, Vol. 64, No. 4, p 438-440, July-August 1972. 3 tab, 12 ref.
Descriptors: *Crop production, *Spring, Irrigation, *Fertility, *Wheat,
Variability, Semiarid climates. Fluctuations, Seasonal, Plant growth regulators,
Nitrogen, Phosphorus, Soil moisture, Proteins, Grains (Crops), Soil-water-plant
relationships.
Identifiers: Iran, Straw.
Application of nitrogen with or without phosphorus, moisture levels and season
have a great effect on yield, growth characteristics and protein content of
winter wheat. Variations in moisture under semiarid conditions of southern
Iran can drastically change yield patterns of winter wheat (Triticum aestivum L)
within the same or over several seasons. An experiment considering effects of
spring irrigation and fertility levels on components of yield, plant character-
istics and yield of grain and straw of 'Roushan' variety of winter wheat was
conducted. The 3-year study showed that grain and straw yields were positively
and significantly correlated with levels of irrigation in each crop season, and
in combined 3 years, correlations for grain yield to levels of fertilizer were
negative and significant. Correlation coefficients showed components of yield
to be more affected by season and irrigation level than other factors, thus
a fluctuation in moisture level shows a fluctuating yield pattern.
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72-73:03P-027
WATER USE BY SUGAR BEETS IN A SEMIARID ENVIRONMENT AS INFLUENCED BY POPULATION
AND NITROGEN FERTILIZER,
Moraghan, J. T.
North Dakota State University, Fargo, Department of Soils.
Agronomy Journal, Vol. 64, No. 6, p 759-762, November-December, 1972. 4 fig,
4 tab, 10 ref.
Descriptors: *Water utilization, *Sugar beets, *Semi-arid climates, *Dry farm-
ing, *Fertilizers, Nitrogen compounds, Plant populations, Crop production,
Consumptive use, Root development. Plant growth regulators, Seasonal, Precipita-
tion (Atmospheric), Water demand, Leaves, Nitrates, Soil-water-plant relation-
ships.
Identifiers: Leaf area index (LAI), Sucrose.
Sugar beets (Beta vulgaris) are deep-rooting crops which seek moisture and are
influenced by nitrogen (N) fertilizer. The decrease in the quality of Ameri-
can beets is of concern. The influence of population and N fertilizer on leaf
area index (LAI) and on water use by beets under dry land conditions in a semi-
arid environment is reported, as little is known of beets in these conditions.
Growing season was characterized by long periods with little precipitation,
where extensive use of stored soil moisture occurred to a depth of at least
183 cm. Populations of 26,400 and 70,700 plants/ha, and N fertilizer rates of
0, 56, 112 and 224 Kg/ha were observed. Higher population and fertilizer
treatments increased water use by 9.5 and 3.5 percent, and yield of sucrose by
20 and 15 percent respectively. LAI increased much more markedly by both
treatments. Greatest effect of increasing population on water use was most evi-
dent in the deepest depths from which soil moisture was utilized. Beets
utilized soil nitrate to at least 152 cm. High yields under dry land conditions
with limited precipitation was the result of the deep rooting nature of sugar
beets and relatively large amount of preplanting available stored soil moisture.
72-73 .-03F-028
EFFECT OF THE SOIL AND PLANT WATER POTENTIALS ON THE DRY MATTER PRODUCTION OF
SNAP BEANS,
Millar, A. A., and Gardner, W. R.
Department of Soils, University Concepcion, Chilian, Chili Concepcion University
(Chile).
Agronomy Journal, Vol. 64, No. 5, p 559-562, 1972.
Identifiers: *Soil-water-plant relationships, *Beans, Dry, Growth, Phaseolus
vulgaris. Plants, Potentials, Production, Rates, Resistance, Soils, Stomatal,
Transpiration.
The dry matter production rate of snap beans (Phaseolus vulgaris L., cv. 'Bush
Blue Lake') growing under field conditions on a sandy soil is analyzed during
a drying period. Measurements of plant- and soil-water potentials, dry matter
accumulation, and stomatal resistance were made as soil-water was depleted,
while the transpiration rate were obtained by a model for a loosely structured
canopy. The transpiration and dry matter production rates decreased curvi-
linearly with soil-water potential. When the soil-water potential decreased
from -0.28 to -0.40 bar, there was 47% reduction in the dry matter production
rate. This is related to the turgor pressure-operated stomatal mechanism. The
adaxial stomatal resistances increased at leaf-water potentials lower than -8
bars, which coincided with a rapid decrease in the dry matter production rate.
Stomatal closure due to water stress resulted in a greater reduction of growth
rate than in transpiration.
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72-73:03F-029
EFFECT OF AERIAL ENVIRONMENT AND SOIL WATER POTENTIAL ON THE TRANSPIRATION AND
ENERGY STATUS OF WATER IN WHEAT PLANTS,
Yang, S. J., and DeJong, E.
Washington State University, Pullman, Department of Agronomy and Soils.
Agronomy Journal, Vol. 64, No. 5, p 574-578, 1972. Illus.
Identifiers: Aerial environment, Capillary conductivity, *Energy status,
Evaporation, Humidity, Soils, Temperature, Texture, *Transpiration, Triticum-
aestivum, *Wheat, Wilting, *Soil-water potential.
Thatcher wheat (Triticum aestivum L.) was grown under 4 combinations of air
temperature and relative humidity in a loam and a clay soil. The relationship
between transpiration rate and soil water potential depended on evaporative
demand and soil texture. The decline in the transpiration rate from its maxi-
mum commenced at higher soil water potentials under conditions of higher
evaporative demand and was more gradual on the clay than on the loam soil,
presumably due to the higher capillary conductivity of the former. Permanent
wilting occurred at soil water potentials of -20 to -25 bars on the loam soil
and at -45 to 50 bars on the clay soil. At these potentials the capillary
conductivities of both soils were about equal. Resistance to water flow in
the plant decreased with increased temperature, while changes in relative
humidity had no consistent effect. The total resistance to water movement in
the plant and the soil increased with decreasing soil water potential and
decreasing air temperature. The relationship between leaf water potential
and relative water content was affected by aerial environment and soil texture.
72-73:03F-030
EFFECT OF MOISTURE STRESS AT DIFFERENT STAGES OF GROWTH: II. CYTOPLASMIC
MALE-STERILE CORN,
Vincent, G. B., and Wooley, D. G.
Iowa State University, Davenport, Cooperative Extension Service.
Agronomy Journal, Vol. 64, No. 5, p 599-602, September-October, 1972. 4 fig,
2 tab, 12 ref.
Descriptors: *Moisture stress, *Plant growth, *Corn (Field), *Crop response,
*Soil moisture, Seeds, Labor, Drought tolerance, Soil-water-plant relationships.
Growth stages, Crop production. Leaves, Water management (Applied), Adaptation,
Water demand, Consumptive use, Water conservation.
Identifiers: *Cytoplasmic male-sterile corn, "Hybrids, *Leaf turgor.
Cytoplasmic male-sterile (cms) corn (Zea mays) hybrids are used extensively in
recent years by commercial seed producers to reduce labor. This study deter-
mines if the greater moisture stress-tolerance of corn plants with male-sterile
cytoplasm was due to their ability to extract more moisture from so.il and retain
it against atmospheric demand. Experiment was conducted on Colo silt loam
soil in 1967 at Ames, Iowa to compare effects of moisture stress at different
stages of growth on Texas male-sterile cytoplasm corn hybrids and their normal
cytoplasm counterparts. Grain yield reduced significantly by imposed moisture
stress. Hybrids with cms did not yield differently from normal counterparts,
but cms hybrids maintained a higher leaf turgor level when stressed. Equally
severe stress intensities were established by withholding irrigation water
until a minimum level of 75 percent leaf turgidity was reached. Normal hybrids
withstood 1 day of serious stress during a 3-day period, while cms hybrids
withstood 3 days of serious stress during a 10-day period before reaching
minimum leaf turgidity. The stress-tolerant cms hybrids have significant
impact on water management and adaptation of corn plants.
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72-73:03F-031
EFFECT OF PLANTING DATE ON WATER-USE AND ITS EFFICIENCY IN DRY LAND GRAIN
SORGHUM,
Blum, A.
Volcani Institute of Agricultural Research, Bet-Dagan (Israel), Division of
Field Crops.
Agronomy Journal, Vol. 64, No. 6, p 775-778, November-December, 1972. 4 fig,
3 tab, 20 ref.
Descriptors: *Dates, *Water utilization, *Water demand, *Crop production,
*Grain sorghum. Planting management, Consumptive use. Efficiencies, Dry farming,
Precipitation (Atmospheric), Seasonal, Soil moisture, Water rates, Plant
growth. Plant growth regulators. Spring, Water supply, Limiting factors, Vege-
tation, Leaves, Weight, Emerging vegetation state, Moisture stress, Adaptation,
Root development, Evapotranspiration.
Identifiers: *Hybrids, Israel, Soil extraction profiles, Tillering, Leaf
diffusion resistance, Heading, Leaf desiccation.
No precipitation occurs in the growing season, and water is provided under dry
land conditions by stored soil moisture in many of the grain sorghum (Sorghum
bicolor (L.) Moench) growing areas. This research was conducted to appraise
the postulation that water regime is the major operative factor responsible
for different yield response of dry land grain sorghum. Four grain sorghum
hybrids were planted on two spring dates for four consecutive years in Israel
under conditions of limited water supply, or preplanting stored soil moisture.
Vegetative development, grain yield and soil water extraction profiles were
determined to show early planting increased grain yield through increased
tillering and greater weight per grain. Early planted sorghum used about half
as much water as the late plant, from emergence to 31 days. Early plants were
less water stressed as evidenced by lower leaf diffusion resistance prior to
heading and smaller reduction in leaf desiccation after heading. Lower water
use by early plants was ascribed to lower potential evapotranspiration, smaller
leaf desiccation and slower root development. Total amount of water consumed
by both time plantings were the same. No differences were noted in terms of
hybrid adaption to early planting or water use. Stored soil moisture is
necessary for dry land sorghum production.
72-73:03F-032
EFFECTS OF WATER AND HEAT ON SEEDLING EMERGENCE,
Feddes, R. A.
Institute for Land and Water Management Research, Wageningen (Netherlands).
Journal of Hydrology (Amst). Vol. 16, No. 4, p 341-359, 1972. Illus.
Identifiers: Bean, Beet Gardens, Heat, Irrigation, *Moisture, Radish, Rainfall,
*Seedling emergence. Soils, Spinach, *Temperature, Water, *Germination.
The combined effect of soil temperature and moisture content on seedling emer-
gence was studied with 4 different kinds of vegetable seeds, radish, spinach,
broad bean and garden beet, in field experiments in a clay and a sandy loam
profile, both with a shallow and a deep groundwater table. Various sowing dates
were applied. The mean daily temperatures of the plots with the higher ground-
water tables were 1-2C lower than the temperature of the plots with the deeper
groundwater tables. With the same groundwater depth, clay was warmer than
sandy loams. The difference in groundwater level play a more important role
than the difference in type of profile. The maxima and minima in the top
soil were higher and the amplitudes decreased with depth faster in soils which
had a deep groundwater table. The decrease .was more marked in the clay than in
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the sandy loam soil. Seeds emerged earlier in sandy loam than in clay. The
sandy loam plots with the shallow groundwater table showed the highest emer-
gence rate as well as the highest total emergence percentage. The mean heat
sums required for 50% emergence were lower on sandy loam than on clay, and the
heat sums of the shallow groundwater plots were lower than those of the deep
groundwater plots. The heat sum required for 50% emergence increased sharply
below a matric pressure of -0.49 bar (above pF (water holding index 2.7) of the
soil. For a fast and adequate seedling emergence both a high temperature and a
sufficient moisture content are necessary. By sprinkler irrigation the sowing
bed can be kept at the desired moisture content.
72-73:03F-033
ESTIMATING DEEP DRAINAGE BETWEEN IRRIGATIONS,
Miller, D. E., and Aarstad, J. S.
Agricultural Research Service, Prosser, Washington, Soil Science Division.
Soil Science Society of America; proceedings. Vol. 36, No. 1, p 124-127, 1972.
Illus.
Identifiers: *Drainage, *Irrigation, Evapotranspiration.
The situation, common in irrigation, in which the water table is deep enough to
be ignored and applied water moves downward by drainage and is taken up by
plants was studied. When plants are transpiring, soil water content is reduced
by both deep drainage and plant extraction. Drainage rates from a wetted
depth of soil are related to the total water contained in that depth when there
is no plant use. This same relation can be used to estimate drainage following
an irrigation when the soil is cropped. However,, in a series of irrigations,
there is a delay between the end of irrigation and the beginning of drainage,
and drainage is overestimated. If reduced irrigation efficiencies can be
tolerated, overirrigation can lengthen time between irrigations, especially
if evapotranspiration rates are low.
72-73:03F-034
COMPUTER SIMULATION ANALYSIS ON RECLAMATION OF SALT-AFFECTED SOILS IN SAN
JOAQUIN VALLEY, CALIFORNIA,
Tanji, K. K.
California University, Davis.
Soil Science Society of America Proceedings, Vol. 36, No. 1, p 127-133,
January-February 1972. 9 fig, 3 tab, 34 ref.
Descriptors: *Saline soils, *Leaching, *Computer models, *Simulation, Sodium,
Gypsum, Boron, Land reclamation, Percolation, Field data, California, Biblio-
graphies, Analysis, Drainage effects, Drainage.
Identifiers: *Salt removal, San Joaquin Valley (California), Soluble salts.
A computer land reclamation model was applied to a field leaching study of
moderately salt-affected profiles. Leaching was accomplished by ponding 15
cm of water intermittently in 3-m by 3-m basins every 1 to 2 weeks. Computer
predictions on the degree of reclamation were compared with measured changes
in soluble salts, soluble boron, and the sodium adsorption ratio to soil
depths of 274 cm. The differences between computed and measured field data
were no more than the horizontal variations found in salt-affected lands in
this area and elsewhere. Predicted drainage water quality and a method for
computing gypsum requirements of sodium-affected profiles are reported. Compu-
ter programming techniques provide a better understanding of the complex salt
problem in irrigated lands.
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72-73:03F-035
SPRINKLER PRECIPITATION GAGE ERRORS,
Kohl, R. A.
Snake River Conservation Research Center, Kimberly, Idaho.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 2,
p 264-265, 271, March-April, 1972. 2 fig, 1 tab, 7 ref.
(See 72-73:020-029)
72-73:03F-036
MATHEMATICAL MODEL OP WATER ADVANCE IN BORDER IRRIGATION,
Bassett, D. L.
Washington State University, Agricultural Engineering Department, Pullman.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 5,
p 992-995, September-October, 1972. 3 fig, 12 ref.
(See 72-73:04A-008)
72-73:03F-037
SEMI-PORTABLE SHEET METAL FLUME FOR AUTOMATED IRRIGATION,
Uhl, V. w., Jr., and Carton, J. E.
Oklahoma State University, Agricultural Engineering Department, Stillwater.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 2,
p 256-260, March-April, 1972. 7 fig, 7 ref.
(See 72-73:04A-009)
72-73:03F-038
DEVELOPMENT OF ASPHALT MOISTURE BARRIER EQUIPMENT,
Fischer, R. C.
International Harvester Company, Hinsdale, Illinois.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 4,
p 630-631, July-August, 1972. 2 fig, 6 ref.
(See 72-73:02G-033)
72-73:03F-039
IRRIGATION CANAL SYSTEM CAPACITY DESIGN CRITERIA,
Earles, J. D.
Harza Engineering Company, Chicago, Illinois.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR3, Proceedings paper No. 9973, p 227-235, September
1973. 1 fig, 2 tab, 4 ref.
Descriptors: *Canals, *Design, Irrigation practices, *Land tenure, *Land use.
Estimating, *Evapotranspiration, Irrigation systems. Irrigation water, Water
requirements, Water delivery, Irrigation efficiency. Farms.
Identifiers: Capacity criteria, *Cropping patterns, *Iran (Khuzestan), Crop
yield.
Estimates of peak period evapotranspiration requirements for projected cropping
are used to determine the minimum capacities necessary for main and secondary
canals. In irrigation project design, the peak period of consumptive use is
the period during which the weighted average daily rate of evapotranspiration
of the various crops grown in the projedt areas is at a maximum. Different
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crops may have their peak rates at different tines. To provide water when and
where needed, at minimum cost, a detailed evaluation is necessary to prevent
over- and under-design of canals. Land tenure after project construction is an
important factor in determining the required capacity of project irrigation
canals. An example of this factor is demonstrated in the Khuzestan area of
Iran which has undergone a recent change in Government land tenure policy.
The policy of subdividing project lands into small parcels for lease or sale
to farmers was changed to permit an agribusiness lease-type of operation during
initial project development. This change caused an increase in the projected
summer cropping intensities, resulting in higher peak irrigation water require-
ments. To deliver the additional water, canal capacity increases of up to
50 percent was required over the original design.
72-73:03F-040
SOME EVIDENCE OF STOMATAL RESTRICTION OF EVAPORATION FROM WELL-WATERED PLANT
CANOPIES,
Shepherd, W.
Commonwealth Scientific and Industrial Research Organization, Aspendale,
Victoria, Australia.
Water Resources Research, Vol. 8, No. 4, p 1092-1095, August, 1972. 2 tab,
4 fig, 10 ref.
(See 72-73:020-021)
72-73:03F-041
OPERATION AND MAINTENANCE OF IRRIGATION AND DRAINAGE SYSTEMS: SECTION III. -
OPERATION,
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IRS, p 237-338, September, 1973. 36 fig, 28 ref.
(See 72-73:04A-027)
72-73:03F-042
UNIFORM IRRIGATION WITH LOW-PRESSURE TRICKLE SYSTEMS,
Myers, L. E., and Bucks, D. A.
United States Water Conservation Laboratory, Phoenix, Arizona.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IRS, p 341-346, September, 1972. 2 fig, 7 ref.
Descriptors: *Irrigation systems, "Application systems, "Orifices, "Irrigation
practices, Pipe flow, Water distribution (applied), Distribution systems,
Irrigation design, Irrigation engineering, Irrigation, Irrigation efficiency.
Application uniformity from low-pressure trickle irrigation systems can be
greatly improved by varying emitter sizes to compensate for friction-induced
pressure changes in the lateral pipe. Low-pressure systems using simple emitter
sizes suffer from nonuniform emitter discharge because friction-induced pressure
changes are a large percentage of total pressure. High-pressure trickle systems
alleviate this problem by using high head loss emitters. Low-pressure systems,
using simple emitters, can have several advantages over high-pressure systems
in reduced manufacturing and operating costs, larger emitter orifices to
reduce clogging, and simpler flow control devices. Comparable application
uniformity can be obtained by varying emitter sizes in the low-pressure systems.
Procedures for designing low-pressure multiple-emitter size trickle systems by
computer or by a simplified computation and graphic method were developed.
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72-73:03F-043
PLANT NUTRIENT CONCENTRATIONS IN RUNOFF FROM FERTILIZED CULTIVATED EROSION
PLOTS AND PRAIRIE IN EASTERN SOUTH DAKOTA,
White, E. M., and Williamson, E. J.
South Dakota State University, Brcokings.
Journal of Environmental Quality, Vol. 2, No. 4, p 453-455, October-December,
1973. 3 tab, 6 ref.
(See 72-73:055-056)
72-73:03F-044
AGRICULTURAL CHEMICALS IN SURFACE RUNOFF, GROUND WATER, AND SOIL: I. ENDRIN,
Willis, G. H., and Hamilton, R. A.
United States Department of Agriculture, Baton Rouge, Louisiana.
Journal of Environmental Quality, Vol. 2, No. 4, p 463-466, October-December,
1973. 4 tab, 11 ref.
(See 72-73:056-062)
72-73:03F-045
MINIMIZING NITRATE SEEPAGE FROM THE HULA VALLEY INTO LAKE KENNERET (SEA OF
GALILEE): I. ENHANCEMENT OF NITRATE REDUCTION BY SPRINKLING AND FLOODING,
Raveh, A., and Avnimelech, Y.
Israel Institute of Technology, Haifa.
Journal of Environmental Quality, Vol. 2, No. 4, p 455-458, October-December,
1973. 3 fig, 4 tab, 11 ref.
(See 72-73:05B-063)
72-73:03F-046
FUNCTIONS TO PREDICT EFFECTS OF CROP WATER DEFICITS,
Stewart, J. I., and Hagan, R. M.
California University, Water Science and Engineering Department, Davis.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR4, p 421-439, December, 1973. 4 fig, 38 ref.
Descriptors: *Agriculture, *Climates, Crop production, Droughts, Economics,
Efficiencies, Evapotranspiration, Irrigation, Management, Planning, Profit,
Research and development, Soil water. Water, Water resources.
A well-advanced research program is aimed at quantitative prediction of rela-
tions between principal crops and water. Goals are to: (1) Estimate functional
relations between crop yield (Y) and water at all water supply levels; water
being defined as seasonal depths of both evapotranspiration (ET) and irrigation
(IRR); and (2) optimize water management by maximizing profit or water use
efficiency or other objective. Davis, California, field and lysimeter studies
with corn show: (1) The Y versus ET function is linear, provided unavoidable
ET deficits from limited irrigation water coincide with those crop growth
stages that influence yield the least; and (2) the Y versus IRR function is
convex, reflecting decreasing irrigation efficiency (percentage of IRR utilized
in ET) as actual crop ET approaches fulfillment of maximum requirements. When
IRR equals zero the two functions become one, and ET derives entirely from
stored soil water and rainfall.
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72-73:03F-047
THEORETICAL IRRIGATION TAILWATER VOLUMES,
Wilke, O. C.
Texas A & M University, Agricultural Experiment Station, Lubbock.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IRS, p 415-420, September, 1973. 1 fig.
Descriptors: *Irrigation, *Agricultural runoff, *Irrigation practices. Irriga-
tion design, Tailwater, Furrow irrigation, Irrigation systems, Surface runoff.
A volume balance theory and graphical relationships for predicting irrigation
tailwater volumes are presented. An equation is derived for determining tail-
water pumping rates for the case where tailwater is continuously recirculated.
Dimensionless graphs illustrate the effects of the time period of runoff on
both runoff volumes and irrigation uniformity. Use of this information could
improve the management of furrow irrigation systems and also aid in the design
of tailwater pits, pumps, and return pipelines.
72-73:03F-048
PHYSICAL MODEL STUDY OF BORDER-STRIP IRRIGATION,
Job ling, G. A., and Turner, A. K.
Engineering, Irrigation, and Water Supply Commission, Queensland, Australia.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR4, p 493-510, December, 1973. 14 fig, 1 tab, 20 ref.
(See 72-73:04A-028)
72-73 .-03F-049
WHEAT RESPONSE TO DIFFERENT SOIL WATER-AERATION CONDITIONS,
Anaya, M. G., and Stolzy, L. H.
California University, Riverside, Department of Soil Science and Agricultural
Engineering.
Soil Science Society of America Proceedings, Vol. 36, No. 3, p 485-489, 1972.
Illus.
Identifiers: *Aeration, Grain oxygen, Protein, Soils, Triticum-Aestivum-M,
*Wheat-M, *Soil water.
A graphical yield surface was constructed for wheat (Triticum aestivum L.)
grown on Yolo silt loam with 13 different soil water-aeration combinations.
The experiment was conducted in a growth chamber under controlled environmental
conditions. 02 over the soil surface was maintained at different percent O2
concentrations 0.9-21%. Various soil water regimes were obtained by irrigation
at different soil suctions 8-99 centibars (cbars). The highest grain yields
were obtained in 2 treatments, one of 9.6% O2 watered at a soil suction of 15
cbars, and another treatment of 4.3% watered at cbars. The lowest production
was in the treatment of 0.9% O2 watered at 99 cbars, and the difference between
the highest and lowest yields was 347%. From the data, the regression equation
for grain yield was Y ħ 15.94 - 0.1324 XI + 3.1813 X2 + 0.1297X22, where Y +
grain yield in g/pot, XI + soil suction in cbars, and X2 +_ percent O2. The
maximum predicted yield calculated from the equation is at a level of 12.0%
of O2 irrigated at a soil suction of 8 cbars. However, the maximum production
recorded was obtained at 9.6% O2. There was a high correlation coefficient
(0.94) between water consumption and grain production. An inverse relationship
existed between grain yield and protein content. The highest level of grain
protein content (22.6%) was obtained in the lowest producing treatment, while
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the lowest level of grain protein content (16.5%) occurred in the highest
producing treatment. The difference in grain protein content between treat-
ments was 37%.
72-73:03F-050
CULTURAL PRACTICES FOR IRRIGATED WINTER WHEAT PRODUCTION,
Unger, P. W., Allen, R. R., and Parker, J. J.
United States Department of Agriculture, Bushland, Texas.
Soil Science Society of America Proceedings, Vol. 37, No. 3, p 437-442, May-
June, 1973. 5 tab, 21 ref.
(See 72-73:020-129)
72-73:03F-051
SIDE ROLL SPRINKLERS,
Miller, M.
Miller (Marion) and Associates, Incorporated, Colorado Springs, Colorado.
Irrigation Age, Vol. 7, No. 6, p 24-25, 62, 65, January 1973. 3 photo, 1 tab.
Descriptors: *Irrigation, *Sprinkler irrigation, *Irrigation systems, Irriga-
tion operation and maintenance, Irrigation efficiency, Irrigation practices.
Surface irrigation. Water distribution (Applied), Aluminum, Farm management.
Pipes, Agricultural engineering.
The side roll sprinkler is the first successful attempt to mechanize the conven-
tional hand move system. This system can be used on any size rectangular-
shaped farm where low to medium height crops are grown. Development of the
system and the present approach to the wheel and coupler attachments are
described. In 90% of the systems, the wheels are connected to the middle of
a pipe length and a coupler, incorporating a riser and drain, connects the pipe
lengths. Components used in the present side roll system are: different
sizes of aluminum pipes, couplers, wheels, power movers, self-alining risers,
and drains. From the standpoint of water distribution, the most popular
system is 1/4 mi long, with a sprinkler every length of pipe. Factors to be
considered when purchasing a side roll system and recommended operating proce-
dures are presented.
72-73:03F-052
FARMING CIRCLES,
Miles, D. L.
Colorado State University, Fort Collins.
Irrigation Age, Vol. 7, No. 6, p 20-21, 48, 53, 56, January 1973. 1 photo.
Descriptors: *Irrigation, *Sprinkler irrigation, Irrigation operation and
maintenance, *Irrigation efficiency, Irrigation practices, Irrigation systems,
Surface irrigation, Water distribution (Applied), Agricultural engineering,
Farm management, Water requirements, Crop response, Planting management.
Identifiers: Irrigation requirement, Cropping patterns.
Circular farming with elimination of end guns, running wheels on ridges, and
smoothing the surfaces are procedures that increase the potential profit of
center-pivot irrigation farming. For a typical 132-acre system, the elimination
of end guns will reduce the irrigated acreage to 122 acres. However, the
uniformity of irrigation will usually result in more total yield than from the
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132 acres without having to till, plant, fertilize, irrigate, and harvest the
additional 10 acres. Running the wheels on a slight ridge reduces rutting and
traction problems as the water will run from the tracks. Recommendations that
ridges be built around the field and circular planting be used for a more
efficient field operation are presented. Smoothing small land undulations and
planting parallel to the wheel tracks to eliminate water trapping will result
in a more uniform infiltration. Preirrigation, a very important farming prac-
tice, when used to the full depth of the root zone, helps to break up surface
crusts at the time of planting, and to condition the soil to accept irrigation
water. Operating pressure of 85 to 90 psi is recommended at the pivot for
common sprinkler spacings of about 30 ft. High operating pressures produce a
more constant application of water which can be absorbed easily by the soil.
72-73:03F-053
SHOULD I IRRIGATE ONLY EVERY OTHER ROW,
Milligan, T.
Irrigation Age, Vol. 7, No. 7, p 16-18, March, 1973. 1 fig, 2 tab.
Descriptors: *Irrigation practices, *Furrow irrigation, Surface irrigation,
Water conservation, Crop response. Crop production.
Tests on irrigating every other furrow have been conducted at the University
of Nebraska. The field getting water applied down every furrow was irrigated
six times, used 14.9 inches of irrigation water to go with the 11.8 inches of
rain during the growing season. That plot made 170 bushels per acre. Where
the same every other furrow was irrigated, the same number of times, 10.7
inches of water was applied and 161 bushels were" harvested per acre. The
every other furrow (alternated) used 10.5 inches of irrigation water and
yielded 163 bushels an acre. Tables showing results of further tests are
presented.
72-73:03F-054
TAILWATER,
Milligan, T.
Irrigation Age, Vol. 7, No. 5, p 6-7, December, 1972. 4 fig.
Descriptors: *Runoff, *Tailwater, Return flow, Irrigation practices. Furrow
irrigation, Water conservation, Soil conservation, Farm ponds.
.Identifiers: Reuse systems.
Economics of tailwater reuse on the Texas plains are discussed. Surveys show
that much of the water required for adequate furrow irrigation is wasted off
the end of the fields. When 3 to 4 wells contributed to one reuse system it
was found that the system will return as much water as one well will produce.
Thus producing a water savings of 25-30%. Tips on the construction and opera-
tion of the reuse system are presented.
72-73:03F-055
REDUCED TILLAGE FARMING: SAVES WATER AND DOLLARS,
Irrigation Age, Vol. 7, No. 3, p 12-14, October, 1972. 2 fig.
Descriptors: Cultivation, Farm management, Soil management, Conservation,
Crop production, Land management. Crop response, Planting management, Soil
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conservation.
Identifiers: Minimum tillage.
Minimum tillage farming, once thought only useful in dryland areas, is now
becoming popular under a wide variety of irrigation systems. The main advant-
ages are : moisture conservation,lower production cost, higher profits, reduced
erosion, better seedling survival, improved soil structure, increased land
opportunity, wildlife habitat, and lower labor requirements.
72-73:03F-056
SOLID SET SPRINKLER IRRIGATION,
Robinson, F. E.
California University, El Centro, Imperial Valley Field Station.
Agricultural Engineering, Vol. 53, No. 4, p 15-16, April 1972. 4 fig, 5 tab.
Descriptors: *Sprinkler irrigation, *Irrigation practices. Crop production,
Arid climates, California, Spatial distribution, *Vegetable crops. Salt
balance.
Identifiers: *Imperial Velley.
In the arid Southwest where irrigation is a necessity, large increases in Long
Imperator carrots, Climax lettuce, Calicel lettuce, Scarlet Globe radishes,
and Yellow Granex onions have been made possible by sprinkler irrigating plants
grown in flat beds using grid spacings with two inch variance ranging from
10 x 10 to 24 x 24. Sprinkler irrigation is important in the arid Southwest
to prevent salt accumulation on the seed row surface until the seeds emerge.
After emergence, the seedlings are then furrow irrigated, allowing the portable
solid set sprinklers to be used in another field. Research indicates that if
all irrigation were done by sprinklers, the furrows could be eliminated. Plants
are being grown in various grid patterns to identify those that produce the
highest marketable yields at the highest degree of uniformity.
72-73:03F-057
AUTOMATED IRRIGATION IS HERE,
Hagood, M. A.
Washington State University, Prosser, Cooperative Extension Service.
Agricultural Engineering, Vol. 53, No. 10, p 16-18, October 1972. 2 tab, 7 ref.
Descriptors: *Sprinkler irrigation, *Trickle irrigation, *Irrigation operation
and maintenance, Irrigation systems, Furrow irrigation, Irrigation efficiency,
Irrigation engineering, Water management (Applied), Automation, Distribution
systems, Costs, Surface irrigation.
Displacement of rural Americans is an inevitable consequence of irrigation
technology that will continue to displace inefficient equipment and labor;
however, this new technology will add to the total growth, efficiency, and
competitiveness of irrigated agriculture. Low-skilled labor is now being
replaced with better trained, better paid, and more dependable managerial
personnel. New irrigation systems make possible development of previously
considered non-irrigable land. Trickle irrigation allows use of low quality
water, as sprinkler irrigation allows waterflow management which can signifi-
cantly affect sediment concentration, nutrient content, and overall water
quality of return flows. Automation of surface systems in open channels main-
tains uniform water levels, in addition to a 30 percent savings in water use.
The costs of owning and operating selected sprinkler systems are presented and
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as the beneficial aspects of type and automation level of various systems are
discussed.
72-73:03F-058
YIELD OF FLUE-CURED TOBACCO AND LEVELS OF SOIL OXYGEN IN LYSIMETERS WITH DIFFER-
ENT WATER TABLE DEPTHS,
Campbell, R. B. , and Seaborn, G. T.
Agricultural Research Service, Florence, South Carolina, Soil and Water Conser-
vation Research Division.
Agronomy Journal, Vol. 64, No. 6, p 730-733, 1972. Illus.
Identifiers: Alkaloids, *Carbon dioxide. Growth, Lysimeters, Nicotiana-Tabacum,
*0xygen, Root, Shoot, *Soil aeration, Sugars, *Tobacco yield, Water tables.
Flue-cured tobacco (Nicotiana tabacum L.) was grown in lysimeters with static
water-table levels at 30, 45, 60 and 90 cm below the soil surface to more
clearly define the level at which a favorable balance between soil aeration and
water supply is attained. The O2 and CO2 content of the soil air was determined
periodically at various depths. Water-table treatment effects were evaluated
in terms of root and shoot growth, yield and quality of tobacco. Dry leaf
yeilds for the 90-, 60- and 45-cm water-table treatments were all significantly
(P greater than or equal to 0.05} greater than that for the 30-cm treatment.
Yields for the 60- and 90-cm water-table levels were larger, but not signifi-
cantly (P greater than or equal to 0.05) larger than the 45-cm treatment.
The yield difference between the 60- and 90-cm treatments was not significant
(P greater than or equal to 0.05). Roots of tobacco recovered from soil above
the 60- and 90-cm water tables weighed only 10% more than roots recovered from
soil above the 30-cm water table. Average CO2 and O2 gradients in the soil
above the water table were nearly equal but of opposite sign. Soil environ-
mental conditions imposed by the 60-cm water-table treatment provided the most
favorable balance between aeration and water supply for tobacco.
72-73:03F-059
INFLUENCE OF IRRIGATION ON THE YIELD AND PERSISTENCE OF FORAGE LEGUMES,
Wahab, H. A., and Chamblee, D. S.
Ministry of Agriculture and Lands, Kuala Lumpur (Malaysia), Division of Agri-
culture.
Agronomy Journal, Vol. 64, No. 6, p 713-716, 1972.
Identifiers: Coronilla-Varia, Disease, *Forage legumes, *Irrigation, Legumes,
Medicago-Sativa, Trifolium-Repens, *Crop yield. Alfalfa, Clover, Crownvetch,
Soil moisture.
The effect of irrigation on the yield of 3 alfalfa (Medicago sativa L.) culti-
vars, crownvetch (Coronilla varia L.) and ladino clover (Trifolium repens L.)
was studied in the field over a 2-year period. The nonirrigated plants received
natural precipitation, whereas the irrigated legumes were supplied with supple-
mental water in addition to the rainfall whenever soil moisture was depleted
to approximately 50% of the available water-holding capacity. At the first
harvest after irrigation in the first year, superior growth of all legumes was
obtained by the use of supplemental water. The benefits of irrigation to some
species and cultivars ended at this point. Yields of alfalfa were sharply
reduced in mid- and late-summer of the second year as a result of irrigation.
Irrigation of the 3 alfalfa varieties resulted in an overall decrease in yield
of 76% at the last harvest. The alfalfa varieties responded differentially to
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irrigation. Most of the stand of crownvetch was lost following the first cut
on the irrigated plots. In contrast to other legumes, irrigation increased
the yields of ladino clover by approximately 19%. Severe infestation by several
diseases was probably a primary factor in the severe stand loss and low yields
of alfalfa and crownvetch under irrigation. Excessive soil moisture due to
precipitation soon after irrigation also possibly contributed to the loss of
alfalfa stands.
72-73:03F-060
INFLUENCE OF WATER MANAGEMENT THROUGH IRRIGATION AND A SUBSURFACE ASPHALT LAYER
ON SEASONAL GROWTH AND NUTRIENT UPTAKE QF CORN,
Robertson, W. K., Hammond, L. C., Saxena, G. K., and Lundy, H. W.
Florida University, Soil Science Department, Gainesville.
Agronomy Journal, Vol. 65, No. 6, p 866-868, November-December, 1973. 3 fig,
3 tab, 8 ref.
Descriptors: *Irrigation, *Drainage, *Deep percolation, Sand, Fertility,
Leaching, Water loss, Asphalt, Water management (applied).
During the past five years improved water management of droughty sandy soils
has been attained by constructing, at a depth of 60 cm, a continuous layer of
asphalt about 0.3 cm thick. Plots on a Typic Quartzipsamment were treated in
1967 and used in 1970 and 1971 to measure seasonal growth and nutrient uptake
of corn in response to the following water management treatments: check,
irrigation, asphalt layer, and irrigation with asphalt layer. Responses to
fertilizer rate and plant population were also obtained. The asphalt layer
increased corn fodder yields above the check and irrigation treatments during
the first 11 weeks when moisture stress was moderate. At this time an 11-day
drought caused a severe water stress on the check and asphalt layer treatments.
The seasonal response of corn to water management showed that the asphalt layer
system was effective in increasing water use efficiency in well-drained sandy
soils.
72-73:03F-061
EFFECT OF GRAVEL MULCH ON CROP YIELDS,
Fairbourn, M. L.
United States Department of Agriculture, Agricultural Research Service, Fort
Collins, Colorado.
Agronomy Journal, Vol. 65, No. 6, p 925-928, November-December, 1973. 3 fig,
3 tab, 12 ref.
Descriptors: *Mulching, *Corn, *Gravels, Soil water, Evaporation control,
Soil temperature, Water conservation.
A study was established to determine if this mulch material might be used to
promote increased crop yields from the precipitation of semi-arid regions.
Treatments of gravel mulch, cornstalk mulch, and a control of bare soil were
used in both laboratory and field experiments to observe their effect on soil
water, soil temperature, and plant response. Evaporation of soil water was
less and soil temperatures were higher under gravel mulch as compared with a
bare soil surface. Increased crop yield on the gravel-mulch treatment appeared
to be due to an interaction of more soil water and higher soil temperature.
Bare soil strips for crop rows and annual regeneration of the gravel mulch were
necessary management practices to permit both crop production and maintenance
of an effective mulch. The study has indicated that gravel mulch not only
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promotes increased crop yields but also has a potential for mechanized appli-
cation and maintenance.
72-73:03F-062
PIMA COTTON LINT YIELD AS INFLUENCED BY IRRIGATION SCHEDULE, CULTIVAR AND ALTI-
TUDE,
Kittock, D. L.
United States Department of Agriculture, Agricultural Research Service, Phoenix,
Arizona.
Agronomy Journal, Vol. 65, No. 3, p 498-501, May-June, 1973. 4 fig, 2 tab,
9. ref.
Descriptors: *Irrigation, *Irrigation practices, *Crop response. Cotton,
Water conservation, Yield equations.
Development of heat tolerant cultivars of American Pima cotton made it desirable
to re-evaluate irrigation practices for hot climates. To accomplish this,
two cultivars and one experimental strain were tested over a period of 6 years
at two altitudes and under several irrigation regimes. There were three basic
irrigation regimes and several modifications of them. The regimes were: wet,
irrigate every 7 to 12 days; medium, 14 to 17 days; and dry, 21 to 28 days.
Individual irrigations were added in amounts necessary to refill the soil
profile. At high altitude, the heat tolerant cultivar, 'Pima S-41, did not
differ in water requirement from the non-heat tolerant cultivar, 'Pima S-3'.
Both cultivars obtained maximum lint production with a total of 80 cm of water
or five post-emergence irrigations. At low altitude, Pima S-4 yielded higher
and required more water than Pima S-3.
72-73:03F-063
CROP RESPONSE TO TRICKLE AND SUBSURFACE IRRIGATION,
Hiler, E. A., and Howell, T. A.
Texas A & M University, College Station.
Paper 72-744, 1972 Annual Meeting American Society of Agricultural Engineers,
Chicago, Illinois, December 1972. 22 p, 6 fig, 3 tab, 18 ref.
Descriptors: *Crop response, ^Irrigation efficiency, *Subsurface irrigation,
*Trickle irrigation, Consumptive use, Evapotranspiration, Growth rates, Lysi-
meters, Irrigation practices, Irrigation systems. Irrigation water, Mist irri-
gation. Wind velocity. Moisture content, Sorghum, Surface irrigation, Bibliograph-
ies, Crop production.
An investigation was conducted to compare wateruse efficiencies using different
irrigation methods, and to evaluate effects of reduced irrigation amounts on
yields using trickle irrigation. Grain sorghum was grown during 1971-72 in a
field lysimeter installation where complete control of the soil water could
be maintained. Irrigation treatments included subsurface, trickle, subsurface
plus mist, trickle plus mist, and surface. Water measurements were made to
determine irrigation amount, storage depletion, and drainage amount, so that
total crop water use could be determined. Trickle and mist treatment resulted
in the highest water efficiencies. The increase in water-use efficiency based
on total water use was 42% for trickle treatment compared to surface treatment.
Grain sorghum growth as indicated by crop height and leaf'area index was greater
for all 1971 intensive treatments than for the surface treatment. Comparison
of 3 levels of trickle irrigation amounts in 1972 indicates that water-use
efficiency increased by 5096 with sparing trickle applications.
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72-73:03F-064
SOIL MOISTURE EXTRACTION AND IRRIGATION DESIGN REQUIREMENTS FOR CORN,
Fischbach, P. E., and Somerhalder, B. R.
Nebraska University, Lincoln.
Paper 72-770, 1972 Annual Meeting American Society of Agricultural Engineers,
Chicago, Illinois, December 1972. 15 p, 2 fig, 5 tab, 7 ref.
Descriptors: *Water requirements, *Corn (Field), *Irrigation design, *Sprinkler
irrigation. Soil moisture. Root zone. Moisture content, Soil-water-plant
relationships, Irrigation systems, Automatic control. Design criteria. Rainfall,
On-site investigations. Consumptive use, Crop production.
Identifiers: Moisture sensors, Silty loams.
With today's automated equipment, irrigation can be a matter of pressing a
button to place a system into operation. However, water must be efficiently
applied and rainfall effectively utilized to minimize water waste and to produce
high crop yields. To determine the amount of water required to produce the
highest corn yield, in 1971-72, field studies were conducted at the University
of Nebraska Field Laboratory. Irrigation frequencies of 1.5, 3.0, 3.5, and
7 days applying water in the amounts of 0.30, 0.24, 0.15, and 0.10 in./day
design criteria equivalent were studied on Sharpsburg silty clay loam soil.
Soil moisture was at field capacity to a depth of 5 ft when corn was planted
on all treatments. Soil moisture extraction patterns were monitored on corn
for each of the different frequencies and amounts of water applied on each
treatment. Design criteria for irrigation system capacity were calculated to
apply the different amounts of water. Irrigation frequencies studied did not
affect corn yields or change soil moisture extraction patterns. Yields averaged
8 bushels/acre greater on treatments where 0.15 in./day design criteria equiva-
lent was applied, regardless of irrigation frequency.
72-73:03F-065
WATER REQUIREMENTS FOR OPTIMUM CROP YIELD,
Shih, S. F., Sneed, R. E., and Sowell, R. S.
Corps of Engineers, West Palm Beach, Florida.
Paper 72-773, 1972 Annual Meeting American Society of Agricultural Engineers,
Chicago, Illinois, December 1972. 16 p, 6 tab, 5 ref.
Descriptors* *Agronomy, *Water requirements, *Crops, Mathematical models. Water
utilization. Root systems. Time, Irrigation efficiency, Computer programs.
Consumptive use; Crop response, Soil-water-plant relationships, Fourier analy-
sis, Growth stages. Growth rates, Root development. Soils, Plant growth, Crop
production.
Identifiersi Coefficients.
Two mathematical models developed to provide input for determining agricultural
water requirements are presented. One determines the water requirement of a
plant as a function of time after planting; the other determines the rooting
depth as a function of time from date of planting and soil type. Both models
are formulated to make daily calculations from planting date through maturity.
Computer programs were developed to determine coefficients of the equations
presented. With these coefficients, the model was then used to predict water
use and rooting depth of plants as a function of time during the growing season.
Predicted water use agreed closely with observed data for selected crops grown
in North Carolina. Applications of the water use model and the root depth
model are tabulated. With the tabulated data and rainfall data, the water-
holding capacity of the soil will be used to determine irrigation water require-
ments for each soil/crop combination in any of the 60 time intervals during the
year.
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72-73:03F-066
FIELD LEACHING BY SPRINKLER AND SURFACE IRRIGATION DURING A CROP SEASON,
Herrasmeier, L. F., and Kaddah, M. T.
Agricultural Research Service, Brawley, California.
Paper 72-723, 1972 Winter Meet American Society of Agricultural Engineers,
Chicago, Illinois, December 1972. 20 p, 4 fig, 3 tab.
Descriptors: *Leaching, *Irrigation, *Sprinkler irrigation, *Surface irriga-
tion, *Salt balance, Drainage, Irrigation effects, Application methods, Sub-
surface drainage, Soil management, Irrigation efficiency. Crop production,
Barley, Salinity, Saline soils, *California, On-site tests, Land reclamation,
Rates of Application.
Identifiers: *Imperial Valley (California), Salt removal.
Several major disadvantages of leaching a field by ponding water led to consid-
ering sprinklers as an alternative. Laboratory tests indicated that leaching
by sprinkler irrigation may not only provide more efficient water use, but
also save time, since when soil is not saturated, simultaneous leaching and
crop production can occur. In Imperial Valley, California, a field experiment
was conducted to determine: (1) the relative leaching effectiveness of sprink-
ling and surface irrigation on barley, and (2) effects of ponding on crop
growth and yield. Results of leaching during 2 barley growing seasons indicated
that applying excess irrigation water to a winter barley crop can effectively
leach salt from the soil, while obtaining high crop yield. Salt removal
improved slightly between drains in the top foot of soil when sprinklers were
used, but no improvement was noted at a depth of 5 ft. Surface irrigation
resulted in increased leaching and gave higher barley yields than sprinkler
irrigation. Application of up to 30% excess water with surface irrigation
and 67% excess water with sprinklers did not adversely affect yields.
72-73:03F-067
DETERMINING IRRIGATION POTENTIAL - A COMPUTER MODEL,
Nimmer, G. L., and Bubenzer, G. D.
Paper 72-726, 1972 Winter Meeting American Society of Agricultural Engineers,
Chicago, Illinois, December 1972. 15 p, 2 fig, 1 tab, 19 ref.
Descriptors: *Water requirements, *Water distribution (Applied), Computer
models, Irrigation, Irrigation efficiency, Irrigation effects. Irrigation
programs, Irrigation systems. Soils, Water supply. Crops, Management, Evapo-
transpiration, Bibliographies, Climate, Wisconsin, Soil properties, Agronomy,
Planning, Data storage and retrieval.
Identifiers: *Irrigation requirements.
A computer model was developed to provide irrigators with the irrigation require-
ments for a crop-soil-management system. In the state of Wisconsin, a complete
data bank of irrigation parameters and a method of data retrieval were developed
for crops, soils, climate, and water supply. Data bank components discussed
are: (1) evapotranspiration rates, (2) crop coefficients, (3) soil character-
istics, (4) precipitation, and (5) ground-water supply. Output from the comput-
er program may be divided into 3 sections: (1) input data in both original and
coded form, and information from the data storage bank related to input data;
(2) results obtained from the water balance, such as weekly values of crop
coefficients, evapotranspiration, and total and effective precipitation; and
(3) summary of irrigation design parameters used throughout the program.
Analysis of preliminary tests indicate general agreement with observed irriga-
tion requirements on sandy soils. Little data are available for comparisons
on.organic and medium textured soils in Wisconsin; however, results obtained
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appear to agree with current irrigation practices on these soils.
72-73:03F-068
REUSE OF SURFACE RUNOFF FROM FURROW IRRIGATION,
Pope, D. L., and Barefoot, A. D.
Oklahoma State University, Stillwater, Department of Agricultural Engineering.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 6,
p 1088-1091, November-December, 1973. 4 fig, 3 tab, 6 ref.
Descriptors: *Furrow irrigation, *Surface runoff, *Water reuse. Agricultural
runoff, *Water conservation. Costs, Pumps, *Oklahoma.
Identifiers: Reuse systems, Storage pit.
Six irrigated fields in the Oklahoma Panhandle were instrumented to determine
the amount and time distribution of surface runoff from furrow irrigation.
Type H flumes with water level recorders were used to obtain a continuous
permanent record of the runoff. The volume of runoff was calculated as a
percentage of the volume of water applied for the individual sets and each
series of irrigation sets. The variation in runoff percent of the individual
sets was analyzed. The characteristics of the time distribution of the runoff
from the irrigation sets were defined and used in the design of reuse systems.
The runoff percentages from the individual irrigation sets were found to be
distributed as a log-normal relationship with a different mean and standard
deviation for each field. Reuse systems can be designed with either cycling
or continuously operated pumps. Cyclic pumping could be used to accomplish
cut-back irrigation. A system with a continuously operated pump requires a
smaller pump and pipe size and would have a lower fixed cost. The total
annual cost of installing and operating reuse systems is justified for five
of the six fields instrumented.
72-73:03F-069
HYDRAULICS AND UNIFORMITY FOR DRIP IRRIGATION,
Wu, I. P., and Gitlin, H. M.
Hawaii University, Honolulu.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR2, p 157-168, June, 1973. 7 fig, 7 ref.
(See 72-73:04A-073)
72-73:03F-070
CHEMICAL METHOD OF PREVENTING LOSS OF INDUSTRIAL AND FRESH WATERS FROM PONDS,
LAKES AND CANALS,
Rosene, R. V., and Parks, C. F.
Dow Chemical Company, Dowell Division.
Water Resources Bulletin, Vol. 9, No. 4, p 717-722, August, 1973. 2 fig, 5 ref.
(See 72-73:03E-001)
72-73:03F-071
HOW MUCH WATER FOR THIS IRRIGATION,
Davis, C. H.
Irrigation Age, Vol. 6, No. 8, p 20, 22, 26, March, 1972. 2 fig, 1 tab.
206
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Descriptors: *Irrigation practices, *Irrigation programs. Soil moisture,
Crop response, Irrigation systems, Irrigation water, Stress.
A non-technical method for estimating the amount of water required for a given
irrigation is presented. The method is based on estimates of the water holding
capacity of a soil according to the basic soil texture. Soil moisture content
is determined by the feel of the soil or by electronic moisture meters.
72-73:03F-072
TIME IT RIGHT,
Hiler, E. A.
Texas A & M University, Agricultural Engineering Department.
Irrigation Age, Vol. 6, No. 10, p 10-14, 16, May, 1972. 1 fig, 4 tab.
Descriptors: *Irrigation practices, *Irrigation programs, Soil moisture,
Crop response. Irrigation systems. Stress.
Proper irrigation scheduling becomes increasingly important when available water
supplies are short and/or costly. With proper irrigation scheduling, improved
crop yields can be obtained and, often more importantly, water-use efficiencies
can be increased. Both timing and amount of irrigation affect water-use effic-
iency; however, research has shown timing has the greatest effect because at
critical growth stages, excessive crop water deficit can irreversibly reduce
the potential yield and quality of the crop. A concept which is useful in
optimizing irrigation timing is stress day index (SDI). The purposes of this
article are to discuss various methods for irrigation timing, to present the
SDI concept, to show how this concept is utilized for timing irrigations, and
to present experimental results comparing the SDI concept with other irrigation
timing methods.
72-73:03F-073
GROW WHEAT AND GRAIN SORGHUM WITH LESS WATER,
Irrigation Age, Vol. 6, No. 11, p 7-10, June, 1972.
Descriptors: Irrigation practices, irrigation programs, Soil moisture.
Crop response, Irrigation systems. Wheat, Grain sorghum.
Methods for obtaining maximum yield from limited irrigation water are discussed
for wheat and milo. The article is a brief summary of work performed at the
Southwestern Great Plains Research Center in Bushland, Texas. Surprisingly
good yields from very limited water supplies have been demonstrated.
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Section XVIII
WATER QUANTITY MANAGEMENT AND CONTROL
CONTROL OF WATER ON THE SURFACE (Group 04A)
72-73:04A-001
PARALLEL DRAINS FROM THE LAPLACE STANDPOINT,
Glover, R. E.
Colorado State University, Fort Collins, Department of Civil Engineering.
Water Resources Bulletin, Vol. 8, No. 1, p 50-54, February 1972. 1 fig, 2 tab,
4 ref.
Descriptors: *Drawdown, *Drainage systems, *Tiles, *Dupuit-Forchheimer theory,
*Laplaces equation, Groundwater movement, Transmissivity, Permeability, Drains,
Saturated flow, Unsaturated flow. Water table.
To keep the water table below the root zone of crops, drains are often installed
in parallel lines at depths and spacings adapted to the needs of the area.
Formulas used for determining drain spacings are generally based upon Dupuit-
Forchheimer concepts. These developments postulate a saturated, permeable
aquifer underlying the irrigated area and an impermeable barrier underlying
the aquifer. If variations of transmissivity due to variations of water-
table level are taken into account the second order differential equation
obtained is nonlinear. An alternative approach is based upon a requirement
that there can be no accumulation of water in any elementary cubical volume
located in the zone of complete saturation below the water table. A Laplace-
type differential equation is obtained on this basis, if the aquifer is homo-
genous and isotropic. A solution for the case of flow to parallel drains
using the Laplace formulation converges toward the solution obtained from
Dupuit-Forchheimer procedures as the ratio of water-table slope to drain spacing
approaches zero.
72-73:04A-002
ESTIMATING SALINITY OF STREAMS IN THE SOUTHWESTERN UNITED STATES,
Pionke, H. B.f Nicks, A. D., and Schoof, R. R.
Agricultural Research Service, Chickasha, Oklahoma, Southern Great Plains
Watershed Research Center.
Water Resources Research, Vol. 8, No. 6, p 1597-1604, December 1972. 3 fig,
4 tab, 9 ref.
Descriptors: *Salinity, *Streamflow, *Statistical models, *Southwest U.S.,
Regression analysis, Mathematical models, Base flow, Surface waters. Water
chemistry, Water quality.
A model is presented for the improved estimation of stream salinity as a
function of streamflow components. The proposed model was constructed by
using base flow and the ratio of surface to base flow. Among individual
parameters tested, the ratio of surface flow to base flow was the best salinity
predictor for ephemeral streams. Conversely, total flow was the best individual
predictor for the stream draining the largest watershed. The proposed model
explained 77.196-95.296 of the variability in stream salinity and never exceeded
a 30% error for any stream as determined from the standard error of estimate.
It was found to estimate more precisely and accurately the salinity of streams
characterized by ephemeral flows than other models.
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72-73:04A-003
OPPORTUNITY COSTS OF A TRANSBASIN DIVERSION OF WATER 1. METHODOLOGY,
Moncur, J. E. T.
Hawaii University, Honolulu, Department of Economics; and Hawaii University,
Honolulu, Water Resources Research Center.
Water Resources Research, Vol. 8, No. 6, p 1415-1422, December, 1972. 22 equ,
6 ref.
Descriptors: *Diversion, *River basins, *Multipurpose reservoirs, *Feasibility,
*Planning, *Linear programming, *Dynamic programming, *Water supply, Water
demand. Reservoir releases. Optimization, Estimating, Biochemical oxygen demand.
Dissolved oxygen, Southwest U.S., *Columbia River, Mathematical models. Systems
analysis.
Identifiers: *Opportunity costs, *Transbasin water diversion.
Water planning agencies in arid and semi-arid regions of the southwestern
states have long been under pressure to obtain water supplies sufficient
to satisfy demands in their fastly growing regions. One source of supply
is the possibility of importing water from rather distant river basins. A
largescale transbasin water diversion project must be feasible not only in
terms of the direct costs of transporting water but also in terms of the value
of services foregone by the exporting region due to the diminution of its water
supply. A general model is developed for estimating the opportunity costs of
diverting water outside a river basin. The procedure adapts the decomposition
algorithm for linear programs to optimize operations of the water system with
respect to time, multiple complementary and competitive uses, and location,
with allowances made for serial as well as parallel configurations of reser-
voirs. The algorithm solves iteratively for the optimal value of the river's
services. Two solutions are sought: one assuming'natural1 inflow conditions
and one assuming depleted inflows to simulate the situation after a diversion.
The difference between these optimal values is a measure of the opportunity
costs incurred by the water-exporting region.
72-73:04A-004
STEPPED WEIR ON AN ANISOTROPIC DRAINED STRATUM OF FINITE DEPTH,
Reddy, A. S., Mishra, G. C., and Seetharamiah, K.
Indian Institute of Science, Bangalore, Department of Civil and Hydraulic
Engineering.
Water Resources Bulletin, Vol. 8, No. 1, p 55-62, February 1972. 6 fig, 2 ref.
Descriptors: *Weirs, *Seepage, *Underseepage, *Anisotropy, Permeability,
Alluvial channels. Flow nets, Groundwater movement, Mathematical studies.
Weirs are sometimes constructed on a two-layered soil. The lower layer may
have much higher permeability when compared to that of the upper layer. In
such a case the lower layer will act as a drainage layer. Further the soil
may be anisotropic with respect to permeability. Using Schwarz-Christoffel
transformation, the pressure distribution and exit gradients may be found for
a weir on an anisotropic drained stratum. The total head at the boundary of
the two strata is assumed to be constant.
72-73:04A-005
RESTORING SUBSURFACE DRAIN PERFORMANCE,
Grass, L. B., and MacKenzie, A. J.
Agricultural Research Service, Brawley, California, Imperial Valley Conserva-
tion Center.
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Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IRI, p 97-106, March 1972. 9 fig, 1 tab, 5 ref,
append.
Descriptors: *Subsurface drainage, *Irrigation operation and maintenance,
*Clogging, *Cleaning, Irrigation, Drainage systems, Silting, Root systems,
Tile drains, Failure, Gypsum, Travertine, Field investigations, Precipitation
(Chemistry), Repairing, Maintenance, Incrustation, Tile drainage, Salinity,
Drainage.
Identifiers: Imperial Valley (Calif), Coachella Valley (California), Sulfur
oxides, Colorado River, Dissolved salts, Irrigated agriculture, Jetting, Drain
tiles.
Restoration of subsurface drain performance is vitally important in preventing
soil salinity buildup. Malfunctioning tile drains must be quickly recognized
by effluent flow measurements, water table elevation changes, and soil profile
or drain effluent salinity increases. Deposits of iron and manganese precipi-
tates in tile drains clog the openings through which water enters, creating
a serious hazard to crops resulting from rising water tables and increasing
soil salinity. Chemical treatment with a 2% mixture, by weight, of sulfur
dioxide gas and water has been successful in restoring drain efficiency.
Other types of mineral deposits encountered are gypsum and travertine. Gypsum
deposits in the form of small crystals can be easily removed by high-pressure
water jetting equipment; however, large, very dense crystals cannot be broken
by jetting equipment or dissolved by chemicals and affected pipes must be
replaced. Travertine deposits react quickly with most acids. The accumula-
tions of very fine soil sediments which occasionally cause tile malfunctions
are most effectively removed by high-pressure jetting equipment. Accumulations
of fine roots can also be removed by this method, but long flexible rotating
rods with cutting blades are best for removing larger roots.
72-73:04A-006
SEEPAGE FROM SHALLOW OPEN CHANNEL,
Hunt, B. W.
Washington University, Seattle, Department of Civil Engineering.
Journal of the Hydraulics Division, American Society of Civil Engineers,
Vol. 98, No. HY5, Paper 8875, p 779-785, May 1972. 3 fig, 4 ref, append.
Descriptors: *Canal seepage, *Open channels, *Surface-groundwater relation-
ships, Furrow irrigation, Darcys law, Recharge, Infiltration, Hydrogeology,
Numerical analysis, Irrigation, Irrigation water.
An approximate Darcy solution was obtained for the two-dimensional seepage
from an open channel upon a homogeneous, isotropic aquifer of relatively
large depth. The linearized solution was obtained for an arbitrary channel
cross section by assuming that the maximum channel depth is small compared
to the channel width. Comparison with a known exact solution for a parti-
cular channel shape suggests that this solution is probably accurate enough for
design purposes when the channel depth is less than 4096 of the channel width.
72-73J04A-007
HYDRODYNAMICS OF BORDER IRRIGATION ADVANCE,
Kincaid, D. C., Heermann, D. F., and Kruse, E. G.
United States Department of Agriculture, Mitchell, Nebraska.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 4,
p 674-680, July-August, 1972. 14 fig, 1 tab, 10 ref.
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Descriptors: *Irrigation practices, *Irrigation design, *Border irrigation,
*Infiltration rates, Irrigation systems, Computer models, Application methods,
Crop production, Agricultural engineering.
A mathematical model simulating border irrigation was developed by numerically
-solving the hydrodynamic equations of overland flow. A power law infiltration
function is used and the resistance is calculated by Manning's equation. The
advance rate is controlled by the overall volume balance of the system. The
moving boundary is the locus of points at some arbitrary depth. Comparisons
of the model with experimental advance data, surface hydrographs and surface
storage volume curves show that the model simulates border flow reasonably
well with a resistance function of the form of Manning's equation. The model
will describe advance for any specified inflow conditions whenever the slope,
infiltration and resistance properties of the border are known.
72-73:04A-008
MATHEMATICAL MODEL OF WATER ADVANCE IN BORDER IRRIGATION,
Bassett, D. L.
Washington State University, Agricultural Engineering Department, Pullman.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 5,
p 992-995, September-October, 1972. 3 fig, 12 ref.
Descriptors: *Model studies, *Surface irrigation, *Border irrigation, Irriga-
tion practices, Mathematical models, Computer models, Infiltration rates,
Agricultural engineering.
Identifiers: Water advance.
A mathematical model is presented which describes the advance of water over a
dry porous bed as in border irrigation. The model uses the complete equations
of continuity and motion for unsteady spatially varied flow. These are solved
by the method of characteristics, with an external shape function and volume
balance technique for advancing the tip. Computed solutions are compared
with laboratory and field tests. Results suggest the model will predict flow
with accuracy acceptable for most field use and comparable to that with which
input data are described.
72-73:04A-009
SEMI-PORTABLE SHEET METAL FLUME FOR AUTOMATED IRRIGATION,
Uhl, V. W., Jr., and Carton, J. E.
Oklahoma State University, Agricultural Engineering Department, Stillwater.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 2,
p 256-260, March-April, 1972. 7 fig, 7 ref.
Descriptors: *Irrigation practices, *Distribution systems, *Automation,
Flumes, Irrigation design, Furrow irrigation, Irrigation, Agricultural engineer-
ing.
A sheet metal flume for automated cut-back irrigation was designed hydraulically
and structurally. Preceding the structural analysis, several types of designs
were investigated considering the problems of ease of assemblage in the field,
support of the channel in the field, and leakage. The basic design consists
of a sheet metal section supported by a structural steel angle framework.
Taking the basic framework selected, several combinations of material design
were considered and investigated theoretically. From these investigations
three structural steel angle frameworks were built and three sizes of sheet
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metal sections chosen. Six combinations were tested and a final design was
selected. A 230-foot section was assembled in the field for testing. Values
of Manning's n were determined from gradually varied flow tests for various
flows and depths of flow. The flume operated satisfactorily.
72-73:04A-010
WHEAT AND GRAIN SORGHUM IRRIGATION IN A WIDE BED-FURROW SYSTEM,
Allen, R. R., Musick, J. T.
United States Department of Agriculture, Bushland, Texas
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 1,
p 61-63, January-February, 1972. 1 tab, 4 fig, 7 ref.
(See 72-73:02G-032)
72-73:04A-011
EFFECT OF ROUGHNESS ELEMENTS ON HYDRAULIC RESISTANCE FOR OVERLAND FLOW,
Kowobari, T. S.f Rice, C. E., and Garton, J. E.
Soil Testing Services Incorporated, Northbrook, Illinois.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 5, p 979-984, September-October, 1972. 4 fig, 4 tab, 8 ref.
(See 72-73:08B-004)
72-73:04A-012
SELECTING A METHOD FOR SCHEDULING IRRIGATION, USING A SIMULATION MODEL,
Lembke, W. D., and Jones, B. A., Jr.
Illinois University, Agricultural Engineering Department, Urbana-Champaign.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 2,
p 284-286, March-April, 1972. 5 fig, 1 tab, 6 ref.
Descriptors: *Irrigation practices, *Mathematical models, *Rates of application.
Irrigation water. Irrigation design. Irrigation efficiency. Computer models.
Soil physics. Irrigation systems.
A water balance model was used to simulate an irrigation system, in order to
compare three irrigation scheduling practices on the two soils for corn in cen-
tral Illinois. For soil with a water-holding capacity of 0.8 in. per ft., the
practice of applying 30 percent of the available water when the soil water
fell to the 70 percent level was the most profitable one. The practice of
applying 40 percent of the available water when the soil water fell to the 60
percent level was not economically feasible on either soil. On soil with a
water-holding capacity of 1.2 in. per ft., there was no need to measure mois-
ture content. A satisfactory rule was to apply 1 in. of net water after any
7-day period during which less than an inch of rain had fallen.
72-73:04A-013
DESIGN CRITERIA FOR IRRIGATION SYSTEMS WITH COMPLEX PIPE LOOPS,
Edwards, D. M., and Spencer, B.
Nebraska University, Lincoln.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 1,
p 76-78, January-February, 1972. 3 fig, 1 tab, 7 ref.
(See 72-73:08B-005)
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72-73:04A-014
SOIL AND WATER LOSSES AS AFFECTED BY TILLAGE PRACTICES,
Onstad, C. A.
United States Department of Agriculture, Agricultural Research Service, Soil
and Water Conservation, Brookings, South Dakota.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 2, p 287-289, March-April, 1972. 1 fig, 6 tab, 8 ref.
(See 72-73:02J-008)
72-73:04A-015
PASTURE IRRIGATION WITH A CENTER-PIVOT SPRINKLER SYSTEM,
Somerhalder, B. R., and Clanton, D. C.
Nebraska University, Agricultural Engineering Department, North Platte.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 5,
p 902-904, 908, September-October, 1972. 1 fig, 6 tab.
Descriptors: *Irrigation practices, *Sprinkler irrigation, *Pasture manage-
ment. Carrying capacity, Forages, Pasture, Crop production.
Identifiers: Center-pivot sprinklers, Beef production.
Irrigated cool season pasture under a 52-acre center-pivot sprinkler system
was grazed with beef cattle for two years at the University of Nebraska, North
Platte Station. Three classes of animals cows and calves, yearlings, and
weaned calves were grazed at different times during each year. Average
investment and operating costs for two years of forage production was $126.04
per acre: average beef gain was 748 Ib. per acre. This resulted in a feed
cost of 16.8 cents per pound of gain.
72-73:04A-016
HYDRAULICS OF A CENTER PIVOT SYSTEM,
Chu, S. T., and Moe, D. L.
South Dakota State University, Brookings.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 5, p 894-896, September-October, 1972. 3 fig, 1 tab, 4 ref.
(See 72-73:08B-006)
72-73:04A-017
A COMPUTERIZED SOLUTION FOR BENCH LEVELING DESIGN,
Smith, E. F., and Edwards, D. M.
Archer Daniels Midland Company, Lincoln, Nebraska.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 4, p 667-669, July-August, 1972. 3 fig, 8 ref.
Descriptors: *Computer programs, *Land forming, Land development, Irrigation
practices, Agricultural engineering. Land use.
Identifiers: Land grading.
The analysis presented in this paper can be used on all digital computers.
Solutions to the program for reshaping the surface of the land resulted in a
large savings in cost and time as compared to the trial-and-error procedure
without the computer. It also made available the possibility of analyzing the
same data with various sets of input restrictions. However, certain limita-
tions are imposed when using this program: (a) Only rectangular areas are
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adaptable to this program. (b) The entire final surface of the bench is graded
to a uniform plane. (c) The digital computer divorces all factors of human
judgment from the solution. Human judgment is the key to successful design
when applied before data reaches the computer.
72-73:04A-018
IRRIGATION IN ANCIENT MESOPATAMIA,
Kang, S. T.
Illinois University, World Heritage Museum, Urbana.
Water Resources Bulletin, Vol. 8, No. 3, p 619-624, June, 1972. 2 fig.
Descriptors: *Irrigation practices, *Salinity, Crop production, History.
A translation of the cuneiform text written on clay tablets is presented.
These writings are the day-by-day records of early irrigation activities.
The problems of salinization and silting were very evident. The government of
modern Iraq is using this information to locate and restore some of the
systems. Decreased production, with time, is shown. These writings can be of
benefit to modern man.
72-73:04A-019
INTERNATIONAL MANAGEMENT OF THE RIO GRANDE BASIN - THE UNITED STATES AND MEXICO,
Day, J. C.
Western Ontario University, London, Canada.
Water Resources Bulletin, Vol. 8, No. 5, p 935-947, October, 1972. 3 fig,
18 ref.
(See 72-73:02E-006)
72-73:04A-020
SUBSURFACE DISTRIBUTION OF NONUNIFORMLY APPLIED SURFACE WATERS,
Hart, W. E.
Colorado State University Agricultural Engineering Department, Fort Collins,
Colorado.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 4,
p 656-661, 666, July-August, 1972. 14 fig, 1 tab, 13 ref.
Descriptors: *Irrigation practices, *Irrigation design, *Sprinkler irrigation,
Irrigation systems. Uniformity coefficient, Computer models, Application
methods. Application equipment. Sprinkling, Crop production.
Sprinkler irrigation systems are evaluated by determining the uniformity of
water as it is applied to the surface of the ground. The plant responds to
the distribution of the water as it occurs within the soil. The gradients
existing within the unevenly wetted soil move moisture laterally (and verti-
cally) within the profile, causing the water within the soil to be more uniform-
ly distributed than indicated by the initial, surface-measured distribution.
The extent of this movement throughout the soil, within a reasonable length
of time, appears to be a function of the following variables: initial moisture
content, average application rate, distribution of water as applied to the
surface, length modulus, soil type, and total applied water. It is apparent
that current methods of designing irrigation systems, which are based almost
exclusively on anticipated initial uniformity, are inadequate if the aim of
the design is to provide the most economical system possible.
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72-73:04A-021
VOLUME BALANCE METHOD FOR COMPUTING INFILTRATION RATES IN SURFACE IRRIGATION,
Lai, R., and Pandya, A. C.
Orissa University of Agriculture and Technology, Bhubaneswar, India.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 1, p 69-72, January-February, 1972. 4 fig, 2 tab, 7 ref.
Descriptors: *Irrigation practices, *Irrigation efficiency, Infiltration,
Surface irrigation, Irrigation design, Infiltration rates, Unsaturated flow,
Irrigation, Irrigation engineering.
Based upon the equation of continuity an empirical infiltration equation can
be developed from the water advance measurements during surface irrigation.
This so called volume balance method of calculating infiltration rate from
surface irrigation data is most practical as it presents the actual mean
conditions that exist during irrigation application. For high degree of accur-
acy, small time increment may be taken and calculations involved can be con-
veniently done by using computer techniques. An example of computation based
upon field data collected at the Indian Institute of Technology, Kharagpur,
India, has been presented to show how the method is used. Copies of the
computer program are available on request from the authors.
72-73:04A-022
TRANSPORT OF SOIL PARTICLES BY SHALLOW FLOW,
Foster, G. R., and Meyer, L. D.
United States Department of Agriculture, Lafayette, Indiana.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 1, p 99-102, January-February, 1972. 3 fig, 2 tab, 15 ref.
(See 72-73:02E-007)
72-73:04A-023
SELF-CLOSING IRRIGATION PIPE VALVE,
Haise, H. R., and Payne, M. L.
United States Department of Agriculture, Fort Collins, Colorado.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IRS, p 517-522, September, 1972. 5 fig, 5 ref.
Descriptors: *Irrigation systems, *Distribution systems, *Valves, *Remote
control, Turnouts, Pipe flow, Pipes, Irrigation engineering, Irrigation design.
A low-head self-closing hydraulic diaphragm irrigation valve that operates on
water pressure in the pipe distribution system has been developed and success-
fully tested. The valve requires a pilot valve and control lines for remote
operation. Pressure head in the system plus velocity head from a pilot tube,
and the differential area of the valve, combine to make closure possible.
Possible uses include control of reservoir outlets, water releases from riser
valves, and routing water in storm sewers to maximize design capabilities.
No outside power source is required.
72-73:04A-024
SHAPE FACTORS IN IRRIGATION WATER ADVANCE EQUATION,
Singh, P., and Chauhan, H. S.
Agricultural University, Agricultural Engineering Department, Pantnagar,
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Nainital, India.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers. Vol. 98, No. IR3, p 443-458, September, 1972. 10 fig, 1 tab, 9 ref.
(See 72-73:020-046)
72-73:04A-025
WATER REQUIREMENTS OF ROSTERED IRRIGATION SCHEMES,
Fitzgerald, P. D., and Arnold, G. C.
Department of Agriculture, Irrigation Research Station, Ashburton, New Zealand.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IRl, p 91-96, March, 1972. 1 fig, 3 tab, 4 ref.
Descriptors: *Irrigation practices, *Irrigation systems, Water distribution
(applied), *Computer models. Distribution systems, Water delivery, Water
demand. Irrigation engineering. Irrigation efficiency, Surface irrigation.
Irrigation, Water allocation (policy), Water requirements, Soil moisture.
Identifiers: New Zealand, Irrigation scheduling.
A method is given whereby the water requirements of a rostered (rotation)
irrigation scheme can be determined by considering the length of the roster
period and the calculated soil moisture deficit at which irrigation is applied.
From this the storage likely to be needed can be calculated. The method is
computer processed so variations can easily be studied. An example of its
application to the Irrigation Schemes of Mid-Canterbury, New Zealand, is given.
72-73:04A-026
RECESSION FLOW IN SURFACE IRRIGATION,
Wu, I.
Hawaii University, Honolulu.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IRl, p 77-90, March, 1972. 6 fig, 1 tab, 9 ref.
(See 72-73:02E-008)
72-73:04A-027
OPERATION AND MAINTENANCE OF IRRIGATION AND DRAINAGE SYSTEMS: SECTION III. -
OPERATION,
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR3, p 237-338, September, 1973. 36 fig, 28 ref.
Descriptors: ^Drainage, ^Drainage systems, ^Irrigation, ^Irrigation systems,
Operations, Water distribution (applied), Water management (applied), Water
reuse.
For the purpose of this manual, the subject of operation is treated by a dis-
cussion of the factors essential to good water management on an irrigation and
drainage system; the staff necessary to accomplish the work and its responsibil-
ity; operating practices and procedures for the handling, movement, disposal
or reuse of water; and the value of good records and communications in these
operations. The irrigation system referred to in this manual is that generally
referring to movement of water from its source to the user, and is that system
prevalent in arid and semiarid areas as well as in humid areas. The use of the
term drainage system refers to systems in which removal of excess surface water
seasonally is normally a necessity.
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72-73:04A-028
PHYSICAL MODEL STUDY OF BORDER-STRIP IRRIGATION,
Jobling, G. A., and Turner, A. K.
Engineering, Irrigation, and Water Supply Commission, Queensland, Australia.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR4, p 493-510, December, 1973. 14 fig, 1 tab, 20
ref.
Descriptors: *Hydraulic models, *Infiltration, *Irrigation systems, Hydraulics,
Model studies, Roughness (hydraulic), Surface irrigation, Uni'form flow, Water
distribution (applied).
A physical model of an irrigation border was constructed and tested. Equations
are developed which describe the profile of the water advancing down the border,
the rates of advance, and recession after the inflow is cut off, in terms of
inflow, infiltration, slope, and surface roughness. These equations are simpli-
fied to a form more suitable for use in design. An illustrative analysis is
.done to determine correct inflows and cutoff times needed to uniformly irrigate
to a desired depth.
72-73:04A-029
PROBLEMS OF CHOOSING IRRIGATION TECHNIQUES IN A DEVELOPING COUNTRY,
Soltani-Mohammadi, G. R.
Pahlavi University, Department of Agricultural Economics, Shiraz, Iran.
Water Resources Research, Vol. 8, No. 1, p 1-6, February, 1972. 4 tab, 13 ref.
Descriptors: *Irrigation practices, *Economics, Comparative costs, Computer
models, Irrigation engineering, Irrigation design, Irrigation systems, Surface
irrigation, Sprinkler irrigation.
A linear programing model is developed to select between modern surface and
portable or semiportable sprinkler systems for two irrigation projects in Iran.
Skilled labor is included in the model as one of the major limiting factors.
For the specified conditions and assumptions, a portable or semiportable sprink-
ler system is indicated to be economically superior to a modern surface irri-
gation system for the development of new lands. However in lands where a
modern surface irrigation system has already been installed the transformation
to sprinkler irrigation is not feasible. A completely automated sprinkler
system is not indicated for either set of conditions in Iran. Primitive
irrigation was not included in this study because of lack of data. Welfare
effects of the choice of techniques are indicated.
72-73:04A-030
DYNAMICS OF ION TRANSPORT DURING MOISTURE FLOW FROM A DOUGLAS-FIR FOREST FLOOR,
McColl, J. G.
Washington University, Seattle.
Soil Science Society of America Proceedings, Vol. 36, No. 4, p 668-674, July-
August 1972. 4 fig, 3 tab, 32 ref. NSF Grant GB-8125.
Descriptors: *Ion transport, *Leaching, *Forest soils, *Lysimeters, Monitoring,
Forests, Forest management, Douglas fir trees, Temperature, Soil water movement,
Clear-cutting.
Identifiers: *Automated field-monitoring system.
Ion transport was studied during periods of moisture flow from the forest floor
using automated equipment in a second-growth Douglas-fir forest in western
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Washington. The transport process was related to the temperature in the forest
floor, the duration of time before flow, and the amount of moisture flow. The
relationship of seasonal climatic changes to the ion transport process, and the
changes in solution concentration during wetting cycles are described. The
study provides a base for predicting possible effects of manipulating natural
forest ecosystems. A warning is given of possible effects of some common for-
est-management practices.
72-73:04A-031
CONSIDERATIONS FOR EFFECTIVE SLOPING LAND DRAINAGE SYSTEMS,
Benoit, G. R., and Bernstein, J.
Agricultural Research Service, Burlington, Vermont, Soil and Water Conservation
Research Division.
Soil Science Society of America Proceedings, Vol. 36, No. 5, p 819-823, 1972.
Illus.
Identifiers: Bypass, Climate, "Drainage systems, Equation, Flow, *Land drain-
age (sloping). Seismograph analysis. Soils, Transpiration, Evapotranspiration,
*Vermont, Water balance.
A 12-plot sloping land drainage study in East Franklin, Vermont, is located on
a model Cabot silt loam-a poorly-drained glacial till fragipan soil. The
plots consist of all combinations of 2 depths (30 and 51 cm) and 2 spacings
(61 and 122 m) of surface drains (diversions) and 3 spacings (none, 30.5, and
61 m) of subsurface drains located 102 cm deep. Drainage, soil water, and
climatic data were used to evaluate a water balance equation for each drain
for 6 selected drainage intervals. A seismographic analysis showed vibrations
in soil depth as related to bedrock configuration. The results showed great
variation in drain performance between drains in the same interval and between
intervals for the same drain. Wide differences observed between values for
drainage plus soil water storage and rainfall minus potential evapotranspiration
seemed to be related to initial soil water content, the gain or loss of soil
water, and the magnitude of potential evapotranspiration. Greatest drainflow
occurred from those subdrains located at points of shallowest soil depths
with bypass flow occurring under the drains particularly during saturated
conditions. A drainage system for wet sloping soil should include: surface
drains for controlled removal of snowmelt surface runoff; subsurface drains
located at the top of bedrock dropoffs, where the bedrock is closest to the
soil surface; subsurface drains systematically spaced between these drains
to intercept bypass flow before it reaches downslope soil surface areas.
72-73:04A-032
TWO- AND THREE-DIMENSIONAL INFILTRATION: SEEPAGE FROM IRRIGATION CHANNELS AND
INFILTROMETER RINGS,
Youngs, E. G.
Agricultural Research Council, Cambridge (England), Unit of Soil Physics.
Journal of Hydrology, Vol. 15, No. 4, p 301-315, April 1972. 17 fig, 2 tab,
16 ref, append.
Descriptors: *Seepage, *Canal seepage, *Laboratory tests, Leakage, Hydraulic
models, Water loss. Analog models, Model studies, "Infiltration, Saturated
flow, Unsaturated flow.
Steady seepage rates from flat-bottomed channels and channels of semi-circular
cross-section were determined in laboratory tank experiments using various
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sands. Good agreement was found with the theoretical relationships, which
assume the flow to be confined to a saturated region bounded by a capillary-
fringe surface, and to be uniform and vertical at great depths. The steady
large-time seepage rates were also obtained in laboratory sand-tank experiments
for the three-dimensional cases of seepage from circular shallow ponds and
hemispherical sources. These agreed with relationships obtained using an
electrolytic tank analog with approximate boundary conditions assumed for the
flow region. A method of analysis of largetime seepage measurements from
irrigation channels and infiltrometer rings yields the hydraulic conductivity
and pressure head at the wetting front.
72-73:04A-033
WATER TABLE DRAWDOWN AROUND AN OPEN DITCH IN ORGANIC SOILS,
Boelter, D. H.
North Central Forest Experiment Station, Grand Rapids, Minnesota, Northern
Conifers Laboratory.
Journal of Hydrology, Vol. 15, No. 4, p 329-340, April 1972. 6 fig, 1 tab,
13 ref.
Descriptors: *Drawdown, *Peat, *0rganic soils, *Drainage, *Ditches, Water
table, Drains, Water levels, Groundwater movement, Land reclamation, Water
yield improvement, Hydraulic conductivity, Forest management.
Water-level control is a potential method of improving the amount and distri-
bution of runoff from peatlands as well as their capability to produce timber,
agricultural crops, and wildlife. The effectiveness of this practice varies
with the hydraulic conductivity of the peat materials through which the water
must flow. An open ditch hastened the drainage of water from surface or near
surface horizons of fibric (moss) peat on a typical lake-filled organic soil.
However, it had little influence on the water table beyond 5 m from the ditch
when the water table was in deeper horizons of moderately decomposed (hemic)
peat. In an organic soil with less decomposed (fibric) peat throughout several
m depth at the surface a similar ditch influenced the water table as far as
50 m from the ditch.
72-73:04A-034
CONTROLLED INSTANTANEOUS APPLICATION OF FREE WATER TO A POROUS SURFACE,
Swartzendruber, D., and Asseed, M. S.
Purdue University, Agricultural Experiment Station, West Lafayette, Indiana.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 967-968, Novem-
ber-December, 1973. 1 fig.
Descriptors: *Infiltration, *Infiltration rates, *Porous media, Seepage, Flow
measurement, Groundwater movement, Hydraulic conductivity, Porosity, Soil
physics.
Instantaneous application of free water to a porous-medium surface is achieved
essentially by a device in which the central feature is a plastic plate per-
forated with small holes. The pressure head of the water can be controlled at
a preselected value between 0 and 1 cm. Water enters the porous medium at
essentially zero external flow resistance, while volume and time of entry can
be measured accurately. No lateral flow of free water occurs, thus eliminat-
ing the disturbing effects of such flow on the porous-medium surface.
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72-73:04A-035
THEORY OF A RECTANGULAR GRAVEL ENVELOPE IN DRAINAGE DESIGN,
Kirkham, D., and Selim, M. S.
Iowa State University, Ames Department of Agronomy.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 517-521, July-
August 1973. 5 fig, 5 tab, 8 ref.
Descriptors: *Subsurface drains, *Subsurface drainage, Soil water movement,
Equations.
Identifiers: Gravel-packed drain tubes.
A theory was developed to determine the radius of a circular drain which is
equivalent to a square drain. A square drain is encountered in practice when
a gravel envelope of square cross section is placed around a subsurface circular
drain. The resistance of the gravel to flow was neglected. The square drain
tube was analyzed for two cases: (1) when an impermeable barrier was at great
depth below the square drain tube center, and (2) when the bottom edge of the
square drain tube lay on a plane impermeable barrier. In both cases it was
assumed that the length of the edge of the square drain tube was small compared
with the distance from the drain's center to a water table over the drain,
and that the drain ran full. For case 1 an equivalent circular drain tube of
radius 1.1772 times the half-width of the square drain tube may be used to
replace the square drain tubes. If the square drains lie on the impervious
layer, as in case 2, the radius of the equivalent circular drain is 1.1037.
72-73:04A-036
STUDIES ON SEEPAGE FROM CANALS WITH PARTIAL LINING,
Subramanya, K., Madhav, M. R., and Mishra, G. C.
Indian Institute of Technology, Department of Civil Engineering, Kanpur, India.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
99, No. HY12, p 2333-2351, December, 1973. 11 fig, 6 ref.
Descriptors: *Seepage, *Seepage control, *Canals, Canal seepage, Canal linings,
Permeability, Phreatic lines, Hydraulics, Canal design.
A study of seepage from partially lined trapezoidal canals in a homogeneous
isotropic porous medium of large depth is done using inversion of hodograph
and Schwarz-Christoffel transformation. The two cases studied are: (1)
Seepage from canals whose sides are lined but bottom unlined; and (2) seepage
from canals whose bottom is lined but sides unlined. It is found that for
every side slope of the canal there is a particular aspect ratio at which the
sides lining or bottom lining results in the same reduction of seepage. For
canals having an aspect ratio more than this, bottom lining is more effective
and for a lesser aspect ratio, sides lining will be more effective. For a
canal having an aspect ratio of 9 and a side slope of 2.5:1, a 50% reduction in
seepage is ensured by sealing the bottom. The loci of the phreatic lines,
resulting in the aforementioned two cases, are also studied.
72-73:04A-037
SOLUTIONS FOR LATERAL OUTFLOW IN PERFORATED CONDUITS,
Berlamont, J., and Van der Beken, A.
State University of Ghent, Department of Civil Engineering, Ghent, Belgium.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
99, No. HY9, p 1531-1549, September, 1973. 11 fig, 3 tab, 17 ref.
220
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Descriptors: *Drainage, *Irrigation, *Hydraulics, Pipe flow, Sprinkler irriga-
tion, Sewage disposal, Water distribution (applied).
This paper gives general solutions for obtaining a uniform lateral outflow,
either by varying the perforation area or the cross-sectional area. The distri-
bution of the lateral outflow in a conduit with constant cross section and con-
stant perforation area is analyzed under normalized form. Appropriate flow
parameters are introduced which allow for inertia or pressure recovery, velo-
city distribution, laminar or turbulent out-flow, and laminar and turbulent
smooth or rought flow. All results are presented in diagrams. A design rule
for nearly uniform discharge under turbulent pipe flow conditions is derived.
The agreement between experimental data and the presented solutions, when the
velocity correction coefficient is properly chosen, sustains the actual
approach.
72-73:04A-038
A SIMULATION MODEL FOR EVALUATING IRRIGATION MANAGEMENT PRACTICES,
Morey, R. V., and Gilley, J. R.
Minnesota University, Agricultural Engineering Department, Saint Paul.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 5,
p 979-983, September-October, 1973. 5 fig, 16 ref.
Descriptors: *Computer models, *Irrigation practices, *Management, Farm
management, Land management, Water management (applied).
A soil moisture budget which can be used to evaluate irrigation management
practices has been presented. Results of a calibration-verification procedure
were included. The model was used to test several irrigation management pol-
icies for two soil types and 24 years of weather data for St. Cloud, Minnesota.
The results give a good insight into the variability in year-to-year transpira-
tion response under no irrigation. They also show the effect of irrigation
policies on improvement of the transpiration ratio. The simulation results in
conjunction with assumptions and additional information about an individual
operator's yield potential, management practices, etc., should be useful in
helping an irrigation operator make better decisions concerning irrigation
feasibility and scheduling procedures. As such, the model should be a useful
aid in irrigation management decisions.
72-73:04A-039
SURFACE IRRIGATION UNDERGROUND PIPELINES WITH MOVABLE RISERS,
Varlev, I.
Institute of Soil Science, Academy of Agricultural Sciences, Sofia, Bulgaria.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 4,
p 787-789, July-August, 1973. 7 fig, 3 ref.
Descriptors: *Irrigation practices, *Surface irrigation, Furrow irrigation,
Border irrigation, Pipelines, Water distribution (applied), Water supply.
Irrigation systems.
Investigations have been successfully completed in the development of surface
irrigation systems where the water is distributed by underground lateral
pipelines having either removable or movable risers which supply water to
either furrows or borders. The pressures used in these pipelines is only
5 to 6 feet of water, which allows the use of the more economical low-pressure
pipe materials. Full automation of the delivery from lateral-to-lateral can be
221
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achieved. These systems have been designed to achieve efficient use of water,
while minimizing labor requirements.
72-73:04A-040
EVALUATING OUTDOOR WEATHERABILITY OF BUTYL RUBBER SHEETING UNDER STRESS,
Dedrick, A. R.
United States Water Conservation Laboratory, Phoenix, Arizona.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 4,
p 769-772, July-August, 1973. 6 fig, 2 tab, 11 ref.
Descriptors: *Rubber. *Membranes, Weathering, Deterioration, Stress, Canal
linings. Impervious membranes, Waterproofing.
Seasonal variation of deterioration and the effect of membrane elongation and
thickness on rate of deterioration were determined for one butyl rubber formu-
lation at Logan, Utah. Deterioration rates were greatest during the high
temperature part of the year. Deterioration rates increased as elongation
increased and as membrane thickness decreased. Short exposure times (a few
weeks) can be used to evaluate the potential life of a butyl rubber membrane
when thickness, stress (elongation), and season are properly considered.
72-73:04A-041
CULVERTS FOR FLOW MEASUREMENT IN IRRIGATION SYSTEMS,
Skogerboe, G. V., Walker, W. R., and Boonkird, V. S.
Colorado State University, Agricultural Engineering Department, Fort Collins,
Colorado.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 2,
p 287-293, March-April, 1973. 8 fig, 2 tab, 9 ref.
Descriptors: *Flow measurement, *Open channel flow, *Culverts, Flow rates,
Water measurement. Gaging stations, Flumes.
This study has shown that the submerged flow analysis used for flow measuring
flumes and weirs can be applied to free surface outlet control flow in culverts.
Also, discharge ratings for horizontal culverts can be graphically shown on a
single plot. Such a plot covers the three flow conditions investigated, which
are inlet control, free surface outlet control, and submerged outlet control.
The results of this study have clearly shown that culverts can definitely be
used as flow measuring structures in irrigation systems. Thus, existing
culverts could be utilized for providing discharge measurements. Also, small
culverts could be employed as portable flow measuring devices. The assumption
that nl = 1.5 was used to simplify the analysis. Further study should be under-
taken to remove this assumption from the flow analysis* Then, generalized
discharge ratings could be developed for a wide variety of inlet, barrel, and
outlet culvert geometries.
72-73:04A-042
IRRIGATION NUMBERA NEW TECHNIQUE TO EVALUATE IRRIGATION ADVANCE DISTANCE,
Sastry, G., and Agarwal, S. C.
Indian Institute of Technology, Department of Agricultural Engineering,
Kharagpur, West Bengal, India.
Journal of Agricultural Engineering Research, Vol. 18, No. 3, p 189-195,
September, 1973. 1 fig, 1 tab, 12 ref.
222
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Descriptors: *Irrigation design, *Irrigation engineering, *Irrigation prac-
tices, Surface irrigation, Irrigation efficiency, Irrigation systems.
Prediction of irrigation advance distance for a given set of initial conditions
such as slope of land surface, inflow stream per unit top width of flow,
infiltration characteristics and hydraulic conductivity of soil bed, is impor-
tant in order to design efficient surface irrigation systems. A dimensional
analysis of variables involved in water advance phenomenon has been made to
derive a satisfactory equation. The data available at this Research Station
has been analyzed and fitted by least square method of curve fitting to yield
an equation of the type M = A(N)B. The slope of each curve B is observed to
be fairly constant and coefficient A has been related with irrigation number.
An irrigation advance function relating these dimensional parameters is pro-
posed.
72-73:04A-043
DEVELOPMENT OF AUTOMATED SURFACE IRRIGATION,
Pohjakas, K.
Agriculture Canada, Research Branch, Research Station, Lethbridge, Alberta.
Canadian Agricultural Engineering, Vol. 14, No. 2, p 72-74, December, 1972.
Descriptors: *Irrigation practices, *Irrigation systems, Automation, Automatic
control, Surface irrigation, Furrow irrigation, Border irrigation. Irrigation.
Surface irrigation by manual methods, because of its high labor requirement,
is rapidly being replaced by automated sprinkler irrigation. Various gates,
valves, dams, and weirs have been developed that, when used, enable a surface
irrigation system to function automatically or by remote control. These com-
ponents must be reliable, inexpensive, and simple to operate. Hardly any of
the recently developed components are being manufactured for commercial use.
Automated equipment can reduce the labor requirement of the traditional surface
irrigation. Further developmental work, field testing, and commercial produc-
tion of automatic water control devices are necessary to make surface irri-
gation competitive with other more automatic systems of irrigation.
72-73:04A-044
TRICKLE IRRIGATION IN AUSTRALIA,
Milne, J.
Irrigation Journal, Vol. 23, No. 6, p 21, November-December, 1973. 1 fig.
Descriptors: *Irrigation practices, *Surface irrigation, Application equip-
ment. Soil moisture. Horticulture, Australia.
A brief history of trickle irrigation in Australia is given. The use of
irrigation scheduling in the operation of the trickle system is also noted.
72-73:04A-045
1973 IRRIGATION SURVEY,
Irrigation Journal, Vol. 23, No. 6, p 11-20, November-December, 1973.
Descriptors: *Irrigation, Irrigation practices, Irrigation systems, Surveys.
A state-by-state summary of irrigated acreage for selected years since irri-
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gation was begun in the state. The following is also given: percent change
per year, amount sprinkled, type of power used by percent, method of irriga-
tion by method, irrigated acreage by crop, and amount irrigated by gravity.
72-73:04A-046
IRRIGATION SURVEY,
Irrigation Journal, Vol. 22, No. 6, p 9-18, November-December, 1972.
Descriptors: ^Irrigation, Irrigation practices. Irrigation systems, Surveys.
A state-by-state summary of irrigated acreage for selected years since irriga-
tion was begun in the state. The following is also given: percent change
per year, amount sprinkled, type of power used by percent, method of irrigation
by method, irrigated acreage by crop, and amount irrigated by gravity.
72-73:04A-047
TYPES OF IRRIGATION SYSTEMS,
Sneed, R. E.
North Carolina State University, Biological and Agricultural Engineering,
Raleigh.
Irrigation Journal, Vol. 23, No. 5, p 6-9, September-October, 1973.
Descriptors: *Irrigation, Irrigation systems. Irrigation practices, Applica-
tion equipment, Distribution systems.
A brief history of irrigation is presented along with census figures of the
growth of irrigation in recent years. The types of irrigation systems are
discussed. The limitations and requirements of each type are discussed briefly.
The entire article is written on a non-technical format.
72-73:04A-048
CONTROLLED SPRINKLER IRRIGATION SYSTEM FOR EQUALIZED WATER DISTRIBUTION DEVELOP'
ED IN ISRAEL,
Rhodesia Agricultural Journal, Vol. 69, No. 4, p 75-76, July-August, 1972.
2 fig.
Descriptors: *Irrigation practices, *Distribution systems. Irrigation systems,
Sprinkler irrigation. Application equipment, Irrigation efficiency.
A new irrigation system has been developed in Israel to achieve maximum con-
trolled water distribution on permanent set sprinkler schemes. Equalized water
distribution with the new sprinkler, offers the obvious advantage of ensuring
against over-saturating areas served by the first sprinklers or under-irrigat-
ing the last points in the network. It prevents water wastage resulting from
over-discharge in the first units to compensate for the loss caused by the
drop of pressureup to 20 percentas the result of friction over the length
of the irrigation pipe and changes in topography experienced in conventional
systems. The savings in water due to complete regulation of the outflow of
each sprinkler is said to range from five to 15 percent of the total water
use for a given plot, depending upon pressure and topographical conditions.
These are low discharge sprinklers designed for use in all types of fruit
orchards for under-the-foliage fixed irrigation.
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72-73:04A-049
SCHEDULING IRRIGATIONS WITH HIGH-SPEED DATA FROM A COMPUTER,
Milligan, T.
Irrigation Age, Vol. 7, No. 10, p 4, 10, 11, May, 1973.
Descriptors: Irrigation, *Scheduling, Irrigation practices, Computer models,
Irrigation systems.
Identifiers: Irrigation scheduling, Computer irrigation.
The workings of a commercial irrigation scheduling firm in Idaho are discussed.
The firm is based on the program developed by Dr. Marvin Jensen at the Kimberly
Research Center.
72-73:04A-050
CLASS 'A1 PAN AND IRRIGATION SCHEDULING,
Milligan, T.
Irrigation Age, Vol. 7, No. 10, p 12-17, May, 1973. 5 fig, 2 tab.
Descriptors: *Irrigation, Irrigation practices. Irrigation design. Application
equipment, Distribution systems.
Identifiers: Irrigation scheduling.
A method is presented whereby a Class A evaporation pan can be used to help
schedule irrigation. The method was developed to be used by non-technical
personnnel. While this method is not as exotic and complete as those using a
computer, it is an economical working aid to the farmers.
72-73:04A-051
SOLID SET ON PECANS,
Irrigation Age, Vol. 7, No. 6, p 30-32, January, 1973. 6 fig.
Descriptors: *Irrigation systems, *Sprinkler irrigation, Surface irrigation,
Irrigation practices, Application equipment, Supplemental irrigation, Pecans.
Identifiers: Solid Set.
A buried solid set sprinkler system is being used on a large pecan orchard.
The Buckner sprinkler heads used are 1/8-inch, low trajectory with an angle of
20 degrees so as to keep the water under the trees as much as possible. Low
foliage on the trees is kept pruned off to facilitate a more even water pattern
and uniform wetting of the area around the tree. Eighteen sprinklers take care
of an acre and each acre has 36 trees. The manually operated system on phase
one will cover the 1,027 acres in 12 days. Each set is for 24 hours. Water
is supplied from river pumps which pump into a 300,000 gallon reservoir. Two
turbine pumps rated at 5,600 gpm push the water from the river through a 22-
inch pipeline to the reservoir. Three 8-inch horizontal centrifugal pumps are
used to bring water out of the storage tank under a pressure of about 75 pounds.
The sprinklers are operated at 55 to 60 pounds psi.
72-73:04A-052
CENTER PIVOTS ON ALFALFA,
Irrigation Age, Vol. 7, No. 6, p 28-29, 60-61, January, 1973. 3 fig.
Descriptors: *Irrigation systems, *Sprinkler irrigation, *Surface irrigation.
225
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Irrigation practices, Application equipment, Corn, Alfalfa.
Identifiers: Center Pivot.
Center pivot sprinklers are being used in northwestern Oklahoma to transform
sparsely vegetated range land into productive alfalfa and corn fields. The
5,340 acres are divided into 29 circles ranging in size from 160 to 240 acres.
The soil types range from deep sand to sandy clay. The wide variation in
application rates possible with the sprinkler systems make them ideally suited
for the project. Water for the system is provided by a series of wells.
72-73:04A-053
BIG GUNS AND BLACK, WAXY GUMBO,
Milligan, T.
Irrigation Age, Vol. 7, No. 6, p 26-27, January, 1973. 1 fig.
Descriptors: *Irrigation practices, *Sprinkler irrigation, Crop response,
Crop production, Alfalfa.
A farmer and a rancher in the midst of the Blackland heavy clay soil area,
near Dallas, Texas, are supplemental irrigating using big gun sprinklers. The
sprinklers deliver 4-1/2 acre inches of water in 20 hours on 10 acres. Five
cuttings of hay were produced averaging 1000 bales per cutting.
72-73:04A-054
SPRINKLIGATION SPECIAL,
Irrigation Age, Vol. 7, No. 6, p 17-19, January, 1973. 2 fig, 1 tab.
Descriptors: *Irrigation, *Irrigation practices, *Sprinkler irrigation, Surface
irrigation. Irrigation systems.
On many soil types, sprinkler irrigation is the only proper choice...the deep
sands, the sandy loams...fields of complex and undulating topography and soils
whose productivity would be permanently impaired by or made costly to restore
if leveled for gravity. And, sprinklers open the way to "spoon" feed water and
"spoon" feed plant nutrients; and often get more production per unit of water
and nutrients applied.
72-73:04A-055
GATED PIPE AND SIPHON TUBES,
Irrigation Age, Vol. 7, No. 8, p 30-31, 34, March, 1973. 1 fig.
Descriptors: Irrigation practices, *Furrow irrigation, Application equipment,
Surface irrigation, Irrigation systems, Siphons.
Comparison of a Nebraska farmer's experience with gated pipe and siphon tubes.
He finds that the gated pipe saves both water and labor.
72-73:04A-056
UNCONVENTIONAL FURROW IRRIGATION,
Irrigation Age, Vol. 7, No. 8, p 36-37, March, 1973. 1 fig.
226
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Descriptors: *Irrigation practices, *Furrow irrigation, Automation, Surface
irrigation, Application equipment, Irrigation systems.
In recent years, Texas A & M scientists at El Paso developed a variable row
spacing system for irrigated cotton that greatly reduced water needs. The
system involved the use of 80-inch spaced furrows separated by wide, flat
beds. The space between the rows of cotton on each side of the furrow was 26
inches. This system reduced the size of seasonal irrigations from six to three
inches per application and lowered total water use by 54 percent compared to
40-inch rows watered in every furrow.
72-73:04A-057
AUTOMATED FURROW IRRIGATION,
Hilligan, T.
Irrigation Age, Vol. 7, No. 8, p 24-25, March, 1973. 1 fig.
Descriptors: *Irrigation practices, *Furrow irrigation, Automation, Surface
irrigation, Application equipment, Irrigation systems.
Automation of the gated pipe system was made possible by an 18-inch air actuated
valve. The valve connects to a riser on a buried pipeline or a tee in an
aboveground supply line. Gated pipe is connected to the valve to distribute
the water down the furrows. The valve may be six or eight inches in diameter,
depending on the size of the gated pipe. The nylon-reinforced butyl rubber
diaphragm is inflated to stop the water flow through the valve. The valve
will fully close when one psi pressure more than the pressure in the supply
pipeline is applied. For instance if the water pressure in the mainline is
three psi, four psi air pressure from the compressor was needed to completely
shut off the water. The Nebraska workers estimate a full quarter-section of
land can be equipped for automated furrow irrigation for about the same money
it takes to equip a quarter section with center-pivot sprinkler...$16,000 to
$20,000.
72-73:04A-058
DRIP IRRIGATION: TEXAS STYLE,
New, L.
Irrigation Age, Vol. 7, No. 11, p 19-21, 23, June, 1973. 1 fig, 1 tab.
Descriptors: *Irrigation practices, *Surface irrigation, Irrigation systems.
Application equipment. Distribution systems, Irrigation design.
Drip irrigated field tests on West Texas orchards, South Plains greenhouses and
Dawson County row crops have recently been initiated. Preliminary results of
these tests are most favorable and Texas farmers seem pleased at the prospect
of this relatively new form of irrigation.
72-73:04A-059
DRIP COUNTRY, U.S.A.,
Hutto, H., Jr.
Irrigation Age, Vol. 7, No. 11, p 32-35, June, 1973. 34 fig.
Descriptors: *Irrigation practices, *Surface irrigation, Irrigation systems,
Application equipment, Distribution systems, Irrigation design.
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A pictorial tour of drip irrigation country, systems, crops, types of emitters,
hardware, and techniques peculiar to this type of irrigation.
72-73s04A-060
THE HISTORY OF DRIP IRRIGATION,
Gustafson, C. D.
California University, Farm Advisor, San Diego County.
Irrigation Age, Vol. 7, No. 11, p 4-6, June, 1973. 1 fig.
Descriptors: *Irrigation practices, Surface irrigation, Irrigation, Distribu-
tion systems. Irrigation programs.
Identifiers: Drip irrigation. Trickle irrigation.
Drip irrigation's history from the first research in Israel to later studies
in the United States, Italy, Japan, Australia, and Mexico is reviewed. New
methods along with a forecast for the future are outlined.
72-73:04A-061
HOW TO DRIP IRRIGATE,
Irrigation Age, Vol. 7, No. 11, p 7-8, 10, 14, June, 1973.
Descriptors: ^Irrigation practices, *Surface irrigation, Application equip-
ment, Irrigation systems.
Identifiers: Drip irrigation.
A general overview of drip irrigation is presented. Some techniques of design-
ing the system are also explained.
72-73:04A-062
DRIP IRRIGATION BIG SUCCESS AT BUENA VTSTA WINERY,
Irrigation Journal, Vol. 22, No. 6, p 7-8, November-December, 1972. 3 fig.
Descriptors: ^Irrigation practices, "Surface irrigation. Application equipment,
Surface irrigation. Irrigation systems.
A description of a large drip irrigation system used at the Buena Vista Vine-
yards is given. The system seems to be very successful in supplying the needed
water and also cuts both water use and cultivation costs.
72-73:04A-063
AUTOMATIC IRRIGATION SUPPLY SEQUENCING VALVE,
Cykler, J. F.
Mauna Kea Sugar Company, Hilo, Hawaii.
Agricultural Engineering, Vol. 53, No. 1, p 21, January, 1972. 2 fig.
Descriptors: *Irrigation practices. Surface irrigation. Sprinkler irrigation.
Hydraulic valves, Automatic control.
This valve improves the man-day performance of irrigation crews handling a
number of 1500 gpm automatic overhead irrigators. It is a primary directional
flow control for a zone of irrigation where water could be switched to either
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of two quick-coupled or buried irrigation pipe lines. This valve assembly is
self-contained with its own power supply and can be either portable or fixed.
The assembly consists of a 6-inch DeZurik 3-way water valve fitted with a
handle and a set screw to float the valve plug. The action of the valve,
through its 90 degree arc of operation, is accomplished by a 4 inch by 12
inch double-acting hydraulic cylinder fitted with tte usual swivel brackets
and rod end clevises. The upstream water pressure provides the driving force
to power the piston. A 100 mesh line filter prevents trash from plugging the
small orifices in the solenoid water valves.
72-73:04A-064
IMPROVED INSTALLATION OP MICROTUBE DRIP IRRIGATION EMITTERS,
Wilke, O.
Texas A & M University, Agricultural Research and Extension Center, Lubbock.
Agricultural Engineering, Vol. 54, No. 5, p 17, May, 1973.
Descriptors: *Irrigation, Irrigation practices, Irrigation systems, Surface
irrigation.
Identifiers: Drip irrigation.
Microtubes as drip irrigation emitters have several distinct advantages - low
cost, good hydraulic characteristics, ease of installation. But if the wall
of the microtube is thin, the tube may be pinched partially or totally closed
where the tube is inserted into a hole punched in the irrigation lateral pipe.
If the microtube is extended from the irrigation pipe, it may be cut by rabbits.
As microtube emitter flows are increased, the water stream may travel several
feet from the emitter. Foliage may be wetted. As the plastic irrigation
pipe twists due to contraction, the stream direction may change, altering the
soil area wetted by the emitter.
72-73:04A-065
SPRINKLER-INDUCED SOIL TEMPERATURE CHANGES UNDER PLANT COVER,
Kohl, R. A.
Snake River Conservation Research Center, Kimberly, Idaho.
Agronomy Journal, Vol. 65, No. 6, p 962-964, November-December, 1973. 5 fig,
1 tab, 8 ref.
Descriptors: *Irrigation practices, *Soil temperature, *Sprinkler irrigation,
Potatoes, Surface irrigation, Irrigation practices, Irrigation design.
An experiment was conducted to determine the amount of soil temperature reduc-
tion to be expected from irrigating potatoes at various intervals. Soil temp-
eratures were measured at the 10-cm depth under potato ridges with various
amounts of plant cover. The mean daily soil temperature at the 10-cm depth in
a silt loam soil after 7 days following irrigation increased as much as 2 C
above the daily irrigated plot with full cover and 4 C above the daily irrigated
plot without cover. Similar soil temperature increases occurred in a loamy
fine sand soil irrigated after 5 days which is the normal irrigation intervals
for these soils.
72-73:04A-066
USE OF SPRINKLERS TO STUDY THE INFLUENCE OF POPULATION DENSITY UPON SEED COTTON
PRODUCTION IN AN ARID AREA,
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Robinson, F. E., and Cudney, D.
California University, Department of Water Science and Engineering, Davis.
Agronomy Journal, Vol. 65, No. 2, p 266-268, March-April, 1973. 4 fig, 12 ref.
Descriptors: *Cotton, *Irrigation practices, *Sprinkler irrigation, Fertili-
zers, Plant populations, Crop response.
The growing period for cotton has been shortened by 2 months in the Imperial
Valley because of an invasion by pink bollworm. The law now requires that
cotton residue be incorporated into the soil early to lower the number of
overwintering larvae. The shorter period for floral development led to re-
examination of yield potential under different plant spacing. Defoliants,
fertilizer, desiccants, and insecticides for pink bollworm control and water
were applied through the sprinkler system. Randomized block designs of
'Stoneville 213' and 'Paymaster 111A1 included plant densities of 15,000,
60,000, 242,000, and 969,000 plants/ha on a flat soil surface. Seeds were
placed by hand at 2 per dibble in a square grid pattern. The bolls per plant
were significantly affected by plant density. The effect of plant density on
boll weight was significant on Paymaster 111A but not on the Stoneville 213.
The highest seed cotton yield occurred where the plants produced the greatest
number of bolls per hectare.
72-73:04A-067
OBJECTIVES OF IRRIGATION MANAGEMENT COMMITTEE,
Heermann, D. F.
United States Department of Agriculture, Agricultural Research Service, Fort
Collins, Colorado.
Presented at Winter Meetings of the American Society of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois. 10 p, 53 ref.
Descriptors: Irrigation, Irrigation practices. Irrigation programs.
The Irrigation Group has reorganized and established a committee for Irrigation
Management. The scope and objectives of the committee are presented. The
interaction of the Irrigation Management Committee and other committees in the
Society are discussed. The challenge for the new committee is to improve the
management and operation of irrigation systems.
72-73:04A-068
OPTIMIZING SURFACE IRRIGATION UNIFORMITY BY NONUNIFORM SLOPES,
Powell, G. M., Jensen, M. E., and King, L. G.
CH/2 Hill, Redding, California
Presented at Winter Meeting of the American Society of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois. 19 p, .6 fig, 22 ref.
Descriptors: *Irrigation, *Irrigation practices, Surface irrigation, Furrow
irrigation. Irrigation design, Irrigation efficiency, Uniformity coefficient.
A mathematical computer model of surface irrigation was developed to consider
nonuniform slopes and depth-dependent infiltration functions. The model is
based on a predictor-corrector technique in which the advance for each time
increment is predicted and the water surface profile computed. After computing
surface and subsurface storage volumes, the predicted advance is adjusted by
a volume balance correction procedure. The computation is fast and verifica-
tion of the model with field data indicates the model is as accurate as
230
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measured input field parameters. The model was used to demonstrate the effect
of slope profile on water distribution in furrow irrigation. A concave slope
profile shows a significant improvement in water distribution over a uniform
slope. A convex slope results in a significantly poorer distribution. The
model can also be used to evaluate existing surface irrigated fields with
uniform or nonuniform slopes.
72-73:04A-069
EVALUATION OF GRADED FURROW IRRIGATION WITH LENGTH OF RUN ON A CLAY LOAM SOIL,
Musick, J. T., Sletten, W. H., and Dusek, D. A.
Southwest Great Plains Research Center, Bushland, Texas
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 6,
p 1075-1080, 1084, November-December, 1973. 11 fig, 1 tab, 13 ref.
Descriptors: *Irrigation practices, *Furrow irrigation, *Infiltration rates,
Surface irrigation, Runoff, Infiltration, Inflow.
Identifiers: Graded furrows.
The effects of length of run on water intake, soil water distribution, grain
sorghum yields and irrigation water use efficiencies were evaluated on graded
furrow irrigated Pullman clay loam at Bushland, Texas, in 1961-63 on a 900-foot
run and in 1965-66 on an 1,800-foot run. Total water intake during the 15
irrigations studied ranged from 1.3 to 6.0 inches, depending primarily on soil
water content at time of irrigation and surface soil consolidation. Intake
rates after runoff started were affected by length of run. As water advanced
down the furrows, an increasing portion of the furrow length reached the basic
rate which caused the average rate for the wetted furrow length to decline.
72-73:04A-070
TRICKLE IRRIGATION - APPLICATION UNIFORMITY FROM SIMPLE EMITTERS,
Bucks, D. A., and Myers, L. E.
United States Water Conservation Laboratory, Phoenix, Arizona.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 6,
p 1108-1111, November-December, 1973. 4 fig, 3 tab, 12 ref.
Descriptors: *Irrigation practices, *Surface irrigation, Application equipment,
Uniformity coefficient, Irrigation systems, Irrigation design.
Identifiers: Drip irrigation.
Procedures for design and construction of two multiple-size systems, using a
stainless-steel and microtube or spaghetti-tube emitter, were developed. Mean
discharge deviations for these simple emitters operated at constant pressure
were from 1.7 percent to 3.3 percent for the stainless-steel emitters, and from
1.8 percent to 2.5 percent for the microtube emitters. Performance by a mult-
iple-diameter stainless-steel emitter system designed for row-crop usage veri-
fied the practicality of changing emitter diameters along the lateral. The
theoretical performance of a 250-foot lateral with a 2-foot emitter spacing,
using five sizes of stainless-steel emitters, showed a mean deviation of 1.7
percent and maximum deviations of +5.2 percent to -6.6 percent from design
discharge. Actual mean deviation from design discharge was 3.1 percent, with
maximum deviations of +8.8 percent to -10.8 percent in the field.
231
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72-73:04A-071
SKEWNESS AND KURTOSIS INFLUENCE ON UNIFORMITY COEFFICIENT, AND APPLICATION TO
SPRINKLER IRRIGATION DESIGK,
Seniwongse, c., Wu, I., and Reynolds, W. N.
Hawaii University, Department of Agricultural Engineering.
Transactions of the American Society of Agricultural Engineers, Vol, 15, No. 2,
p 266-271, March-April, 1972. 15 fig, 2 tab, 10 ref.
Descriptors: *Irrigation, *Irrigation practices, *Irrigation methods, Sprink-
ler irrigation, Uniformity coefficient.
Frequency analysis indicate that about 70 percent of sprinkler data, that
portion of the data where the uniformity coefficients are 70 percent or greater,
can be fitted by a gamma distribution. A preliminary study has shown that only
a few low-uniformity sprinkler tests fit an exponential distribution. No
sprinkler data were found to fit a poisson distribution. Skew and Kurtosis
can be related to sprinkler uniformity coefficients with values of 70 percent
or less. The distribution of low uniformity data is generally positively
skewed.
72-73:04A-072
FURROW IRRIGATION FOR HAWAIIAN SUGARCANE,
Vaziri, C. M., Collins, H. G., and Reynolds, W. N.
Hawaiian Sugar Planters Association, Agricultural Engineering Experiment
Station, Honolulu.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR1, p 1-14, March, 1973. 4 fig, 3 tab, 3 ref.
Descriptors: Irrigation, *Irrigation practices, *Furrow irrigation, Hawaii,
Hydraulics, Infiltration, Sugarcane, Water distribution (applied), Water control.
Empirical equations describing infiltration, advance, recession, and opportunity
time for infiltration were developed by analysis of inflow-outflow-time measure-
ments recorded during furrow irrigation of sugarcane. The measurements repre-
sent field conditions at various sugarcane ages on the Molokai soil series.
A concept of relating furrow infiltration as a function of furrow length is
presented. The development of equations and tables for use in the design and
efficient operation of sugarcane furrow irrigation systems in the Hawaiian
Islands is described.
72-73:04A-073
HYDRAULICS AND UNIFORMITY FOR DRIP IRRIGATION,
Wu, I. P., and Gitlin, H. M.
Hawaii University, Agricultural Engineering Department, Honolulu.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR2, p 157-168, June, 1973. 7 fig, 7 ref.
Descriptors: *Irrigation, *Irrigation practices. Surface irrigation, Irriga-
tion efficiency. Irrigation systems. Pipe flow. Uniformity coefficient.
Identifiers: Drip irrigation, Pressure distribution.
A drip irrigation system consists of a main line, submains, and laterals and
emitters. The flow condition in the submain and laterals is steady, spatially
varied with lateral outflows; the discharge is decreasing with respect to the
length of the line. By considering them as smooth pipes. Biasins equation for
232
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friction coefficient is used to determine energy drop between outlets along a
drip irrigation line. The energy gradient line is not a straight line but a
curve of exponential type which can be determined by calculating energy drop
of all sections along the line. A simple way of estimating energy gradient
line with only about 1% of error can be done by dividing the line into three
or four segments and using the average discharge for each segment of calculate
energy drops along the line. The pressure distribution along the line can be
determined for both level and sloping surfaces.
72-73:04A-074
CENTER PIVOT PROBLEMS,
Irrigation Age, Vol. 6, No. 9, p 38-40, April, 1972. 1 tab.
Descriptors: Irrigation practices, Surface irrigation. Sprinkler irrigation,
Irrigation systems, Irrigation design. Application equipment.
The problems associated with center pivot sprinkler systems are outlined.
Reasons for not using marginal land are explained. A chart for figuring your
chances for success is presented.
72-73:04A-075
DETERMINATION OF WATER INTAKE RATE FROM RATE OF ADVANCE,
Singh, P., and Chauhan, H. S.
G. B. Pant University of Agriculture and Technology, Pantnagar, Nainital,
India.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 6,
p 1081-1084, November-December, 1973. 4 fig, 14 ref.
Descriptors: *Infiltration rates, *Soil, Infiltration, Infiltrometers, Moisture
meters. Infiltration, Surface irrigation.
The relationship obtained is an attempt to improve existing methods for esti-
mating intake rate in surface irrigation based on rate of water advance data.
The comparison of the relationship with experimental data suggests that the
cylinder in infiltrometers under-estimate intake rate at small values of time
and over-estimate the intake rate at large values of time. The inflow-outflow
method also may not represent actual intake rate because of errors due to
surface storage. The method based on rate of water advance provides a good
estimate of intake rate in surface irrigation.
72-73:04A-076
SPRINKLIGATION AS SEEN AND DONE BY THE OPERATOR,
Irrigation Age, Vol. 6, No. 6, p 10-24, January, 1972. 12 fig.
Descriptors: *Irrigation practices. Surface irrigation. Sprinkler irrigation,
Irrigation systems, Irrigation design. Application equipment.
The field of sprinkler irrigation is reviewed. The various types of systems
are discussed including: hand move, solid set, wheel move, and center pivot
systems. The importance of proper management is stressed.
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72-73:04A-077
DRIP, DRIP, DRIP, DRIP, DRIP,
Irrigation Age, Vol. 6, No. 7, p 14-16, 39-40, February, 1972.
Descriptors: "Irrigation practices, "Irrigation systems, Surface irrigation,
Irrigation, Irrigation design.
A revolutionary new development in irrigation developed and perfected in Israel,
will be introduced on a major scale in the United States. Mr. Symcha Blass of
Tel Aviv, originator of trickle-root irrigation widely utilized in Israel and
the Netafim Drip Irrigation firm, its manufacturer, signed a licensing agree-
ment in September with industrialist Howard Klein of Washington, D. C., who
heads an agro-technical organization formed to install this system throughout
the United States.
72-73:04A-078
MORE PRODUCTION...FEWER IRRIGATIONS,
Milligan, T.
Irrigation Age, Vol. 6, No. 12, p 20, 21, 26, 27, July, 1972. 1 fig, 1 tab.
Descriptors: "Irrigation practices, "Irrigation programs, Soil moisture,
Crop response, Irrigation systems, Surface irrigation.
Briefly describes irrigation activities in non-technical terms. Approximate
figures for peak water use by various crops are given by climate.
72-73:04A-079
PRELIMINARY OBSERVATIONS ON THE USE OF FERTIGATION.. .NEBRASKA STYLE,
Volk, R. R.
Irrigation Age, Vol. 6, No. 8, p 28-29, 32, March, 1972. 1 fig, 1 tab.
Descriptors: "Fertilization, "Application methods, Crop response, Corn,
Irrigation, Timing, Farm management.
A study of present forms of fertilizer application vs. "fertigation" was carried
out at the University of Nebraska Mead Field Laboratory in the summer of 1971
on a silty clay loam soil. The study compared sidedress and irrigation water
applied nitrogen solution. All plots received equal amounts of water and were
planted to the same hybrid corn. Sprinkler applied nitrogen was uniformly
extracted throughout the soil profile by the corn plants in all treatments.
The check had the highest amount of nitrates removed at the four feet depth.
This means the corn was in need of more nitrogen and the amount of starter
supplied was not sufficient. The study did not differentiate yield differences
between sidedress and irrigation water applied nitrogen.
72-73:04A-080
DO I REALLY NEED TO IRRIGATE TODAY,
Davis, C. H.
Irrigation Age, Vol. 6, No. 7, p 61-62, 64, February, 1972. 1 fig.
Descriptors: "Irrigation practices, "Soil moisture, Crop response. Irrigation,
Irrigation design, Timing.
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A non-technical method for determining when to irrigate is presented. The
method is based on average soil moisture holding capacity for soil types.
The moisture content is determined using electronic soil moisture probes.
72-73:04A-081
KNOW YOUR SPRINKLER APPLICATION RATES,
New, L.
Texas Agricultural Extension Service.
Irrigation Age, Vol. 6, No. 6, p 58-59, 62-63, 66-69, January, 1972. 1 fig,
3 tab.
Descriptors: *Irrigation practices, *Surface irrigation. Sprinkler irrigation,
Irrigation systems. Application equipment, Application methods, Rates of
application.
A method for determining sprinkler application rates is presented. The method
is designed for use by non-technical personnel. Tables are given for ease of
application. Detailed examples are provided.
72-73:04A-082
GUIDELINES FOR SUCCESSFUL CENTER-PIVOT IRRIGATION,
Miller, M.
Irrigation Age, Vol. 6, No. 6, p 8, 76-77, January, 1972. 2 fig.
Descriptors: Irrigation practices. Surface irrigation, Sprinkler irrigation,
Irrigation systems, Irrigation design.
A summary of the factors necessary for successful operation of a center-pivot
sprinkler system is presented. A list of Do's and Don'ts has been developed.
A state-of-the-art summary is included.
72-73:04A-083
GATED PIPE AND REUSE SYSTEM,
Irrigation Age, Vol. 6, No. 9, p 18-19, 45, April, 1972. 2 fig.
Descriptors: *Irrigation practices, Surface irrigation, Furrow irrigation,
Irrigation systems, Irrigation design.
The layout of a 160-acre farm irrigation system using gated pipe and a tail-
water reuse system is presented.
72-73:04A-084
IRRIGATION,' DRAINAGE AND SALINITY
UNESCO/FAO
Hutchinson and Company (Publishers) Ltd. 3 Fitzroy Square, London Wl. 1973,
510 p.
Descriptors: *Irrigation, Irrigation effects, Irrigation water, *Drainage,
Salt balance, Saline soils. Saline water, *Salinity, Soil chemistry.
235
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Throughout history, irrigation in arid zones has often led to soil salinization,
thereby creating a problem which has faced man for centuries. With the increase
of the world's population and the rapid development of irrigated areas, this
question becomes more and more urgent. Not only must unproductive lands be
placed under cultivation, but the productivity of irrigated areas must also be
maintained. The experience gained in recent decades, along with a considerable
amount of research which has been conducted regarding irrigation, drainage, and
salinity, have produced a great variety of data. This book is a compendium of
material prepared by numerous investigators throughout the world. The book
not only covers the development of scientific knowledge, but also provides
practical guidelines for field solutions.
72-73:04A-085
ARID ZONE IRRIGATION,
Yaron, B., Danfors, E., and Vaadia, Y.
Springer-Verlag, New York, Heidelberg, Berlin. 1973. 434 p.
Descriptors: *Arid lands, *Irrigation, Irrigation practices, Salinity, Salt
balance. Soil chemistry. Soil physics, *Soil-water-plant relationships, *Water
requirements.
This book has been written for agronomists, soil scientists, water engineers and
plant physiologists who want a clear presentation of irrigation fundamentals
in arid and semi-arid zones. This treatise provides an understanding of the
basic principles governing irrigation technology and helps to overcome the
problem of water shortage in arid zone agriculture. This book, written by a
large numer of specialists and covering a broad spectrum of different disci-
plines, is a synthesis of general up-to-date information, and the results of the
author's own research. The book covers such topics as water resources, soil-
water-plant relationships, chemistry of irrigated soils, field investigations,
soil and water salinity, irrigation practices and crop water requirements.
236
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Section XIX
WATER QUANTITY MANAGEMENT AND CONTROL
GROUNDWATER MANAGEMENT (Group 04B)
72-73:04B-001
SELECTED METHODS OF AQUIFER TEST ANALYSIS,
Schicht, R. J.
Illinois State Water Survey, Urbana.
Water Resources Bulletin, Vol. 8, No. 1, p 175-187, February 1972. 8 fig,
27 ref.
Descriptors: *Aquifer characteristics, *Analytical techniques, *Hydrogeology,
Pumping, Transmissivity, Permeability, Water yield, Drawdown, Storage coeffic-
ient. Confined water, Water table.
Identifiers: *Aquifer testing, Aquifer evaluation, Pumping tests.
Changes in groundwater levels due to a well discharging at a constant rate are
used with various formulas to determine hydraulic properties of aquifers and
their confining bed and to detect the presence of aquifer boundaries. These
formulas are generally solved by graphical methods. Graphs of drawdown versus
time after pumping started, and/or drawdown versus distance from the pumped
well, are used to solve formulas which express the relation between the hydraul-
ic properties of an aquifer and its confining bed and the lowering of water
levels in the vicinity of a pumped well. The principal hydraulic properties
are aquifer transmissivity, the coefficient of storage, and the vertical
permeability of the confining bed. Aquifer pumping test procedures are describ-
ed; also methods of aquifer tests analysis presently being used by the Illinois
State Water Survey.
72-73:048-002
SALTWATER INTRUSION INTO AQUIFERS,
Bruington, A. E.
Los Angelos County Flood Control District, California.
Water Resources Bulletin, Vol. 8, No. 1, p 150-160, February 1972. 11 fig.
Descriptors: *Saline water intrusion, *Aquifers, *Hydrogeology, Withdrawal,
Water levels, Groundwater movement, Injection wells, Water pollution sources,
Brines, Saline water systems, Reviews, History.
Salt-water intrusion into fresh groundwater aquifers is common throughout the
United States. There are three mechanisms by which intrusion occurs. One is
the reversal or reduction of groundwater gradients, which allows saline water to
move. A second is through the destruction of natural barriers that formerly
prevented the movement of salt waters or separated bodies of fresh and salt
water. The third is the improper disposal of waste saline water. One solution
to the problem is the pressure barrier system used in Los Angelos County, where
a line of injection wells was installed parallel to the seacoast. Fresh
water is injected into these wells under pressure so that a pressure barrier
is formed high enough to control intruding sea water. The pumping barrier is
a line of pumping wells between the source of intrusion and the inland pumping
fields. These wells are pumped at a rate which will cause a groundwater press-
ure trough to be formed along the line of wells low enough so that sea water
cannot pass inland. Since the problem usually stems from over pumping, a
program of reduced pumping can be developed. Another way is to continue
237
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pumping in the historical pattern but increase the available groundwater supply
by recharge.
72-73:04B-003
GROUNDWATER RECHARGE,
Brown, R. F., and Signer, D. C.
Water Resources Bulletin, Vol. 8, No. 1, p 132-149, February 1972. 1 fig,
1 tab, 40 ref.
Descriptors: *Artificial recharge, *Texas, *Groundwater recharge. Water spread-
ing. Recharge wells. Pit recharge. Recharge, Water storage. Water quality,
Hydrogeology, Water resources development.
An evaluation of current knowledge of processes and problems of artificial
recharge indicates that a great deal of additional research is necessary before
recharge feasibility can be evaluated in most situations. Experience in using
recharge wells on the Southern High Plains of New Mexico and Texas yields
predictions of success when using good quality water, and failure when recharge
water contains high concentrations of particulate matter. Surface spreading
is a more suitable method when water has a high sediment content, but may not
be feasible in some hydrogeologic situations. Theoretically, well construction
should be important to the success of injection recharge operations, but little
experimental work exists to support this view. Results of recharge experiments
on the Southern High Plains are reviewed.
72-73:04B-004
COMBINED SURFACE WATER-GROUNDWATER ANALYSIS OF HYDROLOGICAL SYSTEMS WITH THE
AID OF THE HYBRID COMPUTER,
Morris, W. J., Morgan, N. W., Wang, B. H., and Riley, J. P.
Utah Water Research Laboratory, Logan.
Water Resources Bulletin, Vol. 8, No. 1, p 63-76, February 1972. 13 fig,
3 tab, 4 ref.
Descriptors: Conjunctive use, *Surface-groundwater relationships, *Irrigation
design, *Water balance, *Computer programs, Evapotranspiration, Digital comput-
ers, Analog computers, Computer models.
Identifiers: *Hybrid computers.
The partial and total differential equations for an integrated surface water-
groundwater system may be solved using a hybrid computer. The computing
technique makes a rapid and accurate study of the groundwater response due to
varying inputs (deep percolation) or outputs (evapotranspiration) from the
groundwater system. Spatial variations in basic vegetation phenomena, such as
pattern, and hydrological parameters, are represented by means of a grid network
which also allows the input of variable boundary conditions. The model is
applied to an area in South America which is subject to high water-table
conditions. Various reclamation schemes and management practices under condi-
tions of irrigated agriculture are assessed.
72-73:04B-005
GROUNDWATER MANAGEMENT ON THE TEXAS HIGH PLAINS,
Jones, O. R., and Schneider, A. D.
Southwestern Great Plains Research Center, Bushland, Texas
238
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Water Resources Bulletin, Vol. 8, No. 3, p 516-522, June, 1972. 3 fig, 1 tab,
16 ref.
Descriptors: *Water management (Applied), *Texas, *Groundwater, *Water quality
control, *Conjuctive use. Water reuse. Return flow, Irrigation water. Irrigation
operation and maintenance, Irrigation practices, Water conservation.
Identifiers: Ogallala aquifer (Texas).
The effects of major water management practices on the pumping requirement from
the Ogallala aquifer are discussed. Demand on the aquifer may be reduced as
much as 15% by recycling irrigation runoff, 25% by recycling irrigation runoff
and irrigating with water from playas, and 29% by recycling irrigation water in
combination with irrigation from playas and artificial recharge of playa water
to the aquifer. Other practices that can result in more efficient use of
precipitation and groundwater are limited irrigation, land forming, soil profile
modification, and improved irrigation systems, thereby reducing the pumping
demand on the Ogallala. Additional water supplies can be obtained by water
harvesting, weather modification, and water importation. The overdraft on
the aquifer can be reduced by the application of sound water management prac-
tices on an area-wide basis.
72-73:04B-006
NONSTEADY FLOW TO A WELL WITH TIME DEPENDENT DRAWDOWN,
Williams, R. A., Lai, R. Y. and Karadi, G. M.
Wisconsin University, Milwaukee, Department of Civil Engineering.
Water Resources Bulletin, Vol. 8, No. 2, p 294-303, April 1972. 6 fig 7 ref.
Descriptors: *Groundwater movement, *Unsteady flow, *Artesian aquifers,
*Drawdown, Water yield, Transmissivity, Aquifer characteristics. Mathematical
studies. Water levels, Water table. Aquifer testing, Specific capacity, Confined
water.
Confined flow toward a single well or finite radius in an extensive aquifer of
uniform transmissibility was studied under the assumption of time-dependent
drawdown. Three particular cases were considered: (a) linear drawdown (includ-
ing constant drawdown; (b) exponential drawdown; (c) periodic (sinusoidal)
drawdown. The differential equation governing unsteady axial symmetric flow
toward a single well in a confined aquifer was solved for the three different
situations by the use of the Laplace transform method. The resulting expres-
sions are integrated by adapting a modified Germant scheme. General computer
programs were developed and operated for several combinations of characteristics.
The results were plotted to show the effect of time dependent drawdown on the
variation of the well discharge and the piezometric head distribution.
72-73:04B-007
STREAM DEPLETION BY WELLS IN THE SOUTH PLATTE BASINCOLORADO,
Danielson, J. A., and Qazi, A. R.
Colorado Division of Water Resources, Denver,
Water Resources Bulletin, Vol. 8, No. 2, p 359-366, April 1972. 5 fig, 1 tab,
3 ref.
Descriptors: *Conjunctive use, *Colorado, *Return flow, *Surface-groundwater
relationships, *Irrigation wells, Irrigation water, Alluvium, Base flow,
Water rights, Prior appropriation.
Identifiers: *South Platte Basin (Colorado).
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Drought conditions combined with improved well technology resulted in a large
amount of well development in the South Platte valley of Colorado during the
period 1952-56. These wells were used for supplemental supply in many cases,
but the application of sprinkler irrigation brought many acres of dry land
into irrigated production. As a result of the groundwater withdrawal, senior
surface appropriators found a decreasing amount of water available in the
streams. The legislature, observing the doctrine of prior appropriation,
ruled that all surface and groundwater in a tributary would be treated and
administered as one resource. Analysis of a segment of the river was made
with careful determination of all inflow and outflow in the study reach to
include correlations required to determine ungaged side-channel inflow and
unmetered irrigation wells. Wells have intercepted normal return flows to the
river resulting in a decreased amount of surface water during the irrigation
season. Stream depletion appears to equal the expected consumptive use of well
water which ranged between 40% to 50% of the groundwater extraction.
72-73:04B-008
SOIL HYDROLOGY IN A SEHIARID WATERSHED,
Nixon, P. R., Lawless, G. P., and McCormick, R. L.
Agricultural Research Service, Weslaco, Texas
American Society of Agricultural Engineers, Transactions, Vol. 15, No. 5,
p 985-991, 1972. 6 fig, 3 tab, 12 ref.
Descriptors: *Soil investigations, *Soil moisture, *Soil-water-plant relation-
ships, *Groundwater recharge, *Soil moisture meters, *Soil water movement,
Hydrology, Arid lands, Watershed management, Soil management, Water yield
improvement. Brush control. Soil profiles, *California, Chaparral, Precipita-
tion (Atmospheric), Infiltration, Percolation, Root zone, Unsaturated flow,
Moisture availability.
Soil hydrology studies in central coastal California (near Lompoc) indicate
that groundwater recharge occurs from on-site precipitation. Changes and
redistributions of moisture in deep sandy profiles at four naturally vegetated
upland sites were studied. Following the summer dry season, the winter rain
water penetrates as a wetting front. This water does not reach the bottom
of the root zone every year; hence, recharge is intermittent. During a 10-year
study, the water-year precipitation ranged from 7 to 31 inches at four sites.
The resulting penetration of rain water ranged from 2.5 to more than 19 feet,
the maximum depth of sampling. Natural recharge occurred once under chamise
brush (Adenostoma fasciculatum), twice under coastal live oak (Quercus agrifolia)
three times under grass-weed, and four times under a canyon oak thicket
(Quercus wislinzenii). Variations are mainly due to precipitation, soil, and
climate characteristics rather than vegetation type at the various sites.
Extrapolation of the results at these four sites suggests that a typical
naturally vegetated site in the sandy area contributes to recharge on the aver-
age of once every 7 years. Conversion of vegetation from brush and trees to
grass is felt to be of questionable value in increasing water yields in this
low rainfall area.
72-73:048-009
ECONOMIC OPTIMIZATION OF A SINGLE-CELL AQUIFER,
Brown, G., Jr., and Deacon, R.
Washington University, Seattle, Department of Economics.
Water Resources Research, Vol. 8, No. 3, p 557-564, June, 1972. 3 fig 12 ref.
Descriptors: *Water quality, *Water treatment, *Aquifers, Surface waters,
240
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Artificial recharge, Water table. Algorithms, Mathematical models, Optimization,
Net profit. Systems analysis, Groundwater availability, Surface water availabil-
ity.
Identifiers: Groundwater management, Groundwater withdrawal, Groundwater
consumption. Pumping tax, Lift levels.
Optimal economic use of an aquifer of over time is analyzed under conditions of
economic growth, inequality of groundwater withdrawal and consumption, and avail-
ability of surface water and artificial recharge; the value of an aquifer as
a natural water quality treatment facility is derived. These conditions are
discussed in depth and presented explicitly as four subject areas that have
hitherto remained unexplored. The stage is set with a simple nonstochastic
groundwater model using optimal control; equations are plentiful throughout
the study. Discussed are optimal life levels and pumping tax for a ground-
water basin characterized by simple growth of the net benefits of water.
Second, the model makes explicit the important distinction between groundwater
use and consumption: Groundwater users with different rates of return flow
should pay different pumping tax rates because they borrow different amounts of
capital. Third, it is shown that introducing surface waters or artificial
recharge replenishment raises the water table and lowers the pumping tax.
And fourth, an explicit distinction is made between water quantity and water
quality that permits the determination of the value of a groundwater basin as
a natural water quality treatment facility.
72-73:048-010
DIGITAL COMPUTER SIMULATION FOR SOLVING MANAGEMENT PROBLEMS OF CONJUNCTIVE
GROUNDWATER AND SURFACE WATER SYSTEMS,
Young, R. A., and Bredehoeft, J. D.
Resources for the Future, Incorporated, Washington, D. C.
Water Resources Research, Vol. 8, No. 3, p 533-556, June 1972. 10 fig, 8 tab,
37 ref.
Descriptors: *Conjunctive use, *Surface-groundwater relationships, *Simulation
analysis, *Water management (Applied), Mathematical models. Optimum development
plan Water resources development Hydrogeology, Stochastic processes.
Identifiers: South Platte River (Colorado).
In river basins where aquifers are intimately associated with streams, the
unrestricted development of groundwater can reduce streamflows and jeopardize
the rights to the flow of surface water. A simulation model was developed to
aid in the solution .of such problems. The model is composed of (1) a hydrolo-
gic model that represents the physical response of the stream-aquifer system
to changes in river flows, diversions, and pumping, and treats streamflow as a
stochastic input and (2) an economic model that represents the response of
irrigation water users to variations in water supply and cost. These elements
were incorporated into a decision framework so that the net income to the
water resource system associated with alternative management schemes could be
measured. The results of operating the model with parameters representing
conditions in the South Platte Valley of eastern Colorado under alternative
institutional and hydrologic conditions are reported.
72-73:048-011
PUMPING AN ARTESIAN SOURCE FOR WATER TABLE CONTROL,
Doering, E. J., and Benz, L. C.
Agricultural Research Service, Mandan, North Dakota, Soil and Water Conserva-
241
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tion Research Division.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR2, Paper 8964, p 275-287, June 1972. 8 fig, 23 ref.
Descriptors: "Drainage programs, *Pumping, "Artesian aquifers, "Water levels,
"North Dakota, Aquifer testing, Hydrogeology, Water table. Leaching, Confined
water, Drawdown.
Identifiers: "Red River Valley (N Dakota).
Pumping of an artesian aquifer in the Red River Valley of North Dakota can be
used to control the water table in the overlying waterlogged and saline agri-
cultural lands at an estimated pumping cost of $0.34 per acre per year. Because
the fine-textured overburden is more than 100 ft thick and has a very low
vertical hydraulic conductivity, continuous pumping will be necessary. By
reducing the artesian pressure, the upward flow of saline water will be stopped,
the water table in the leaky overburden will be reestablished at a greater
depth, and salts can be leached from the root zone by precipitation. Even
though the water pumped from the artesian aquifer is saline, the amount would
be small enough thai; its discharge into the Red River of the North at low flow
would not make the river water unsuitable for domestic use.
72-73:048-012
WATER TABLE DRAWDOWN DUE TO A PUMPED WELL IN AN UNCONFINED AQUIFER,
Streltsova, T. D., and Rushton, K. R.
Birmingham University (England). Department of Civil Engineering,
Water Resources Research, Vol. 9, No. 1, p 236-242, February 1973. 4 fig,
2 tab, 4 ref.
Descriptors: "Groundwater movement, "Drawdown, "Withdrawal, "Unsteady flow,
"Aquifer testing, Water level fluctuations, Water yield, Saturated flow, Unsat-
urated flow. Percolation, Capillary fringe, Capillary water, Drainage.
A general solution of the water table drawdown for unsteady radial flow to a
pumped well is considered. Tabulated values for the free surface function are
calculated for the range of parameters occurring in practical situations. A
comparison with the available solution of Boulton is made, an appraisal of the
assumptions being introduced in the derivation of the solutions. A numerical
example of unsteady radial flow in an unconfined aquifer with details of the
main part of the computer program is presented.
72-73:04B-013
FLOW NEAR A PUMPED WELL IN AN UNCONFINED AQUIFER"UNDER NONSTEADY CONDITIONS,
Streltsova, T. D.
Birmingham University, (England), Department of Civil Engineering.
Water Resources Research, Vol. 9, No. 1, p 227-235, February 1973. 5 fig,
1 tab, 10 ref.
Descriptors: "Groundwater movement, "Drawdown, "Withdrawal, "Unsteady flow,
"Aquifer testing, Water level fluctuations, Water yield, Saturated flow, Unsat-
urated flow, Percolation, Capillary fringe, Capillary water, Drainage.
The problem of unsteady radial flow in an unconfined aquifer is considered as
a boundary value problem with discontinuous initial conditions at the surface
of the well. The discontinuity of heads occurs at the surface of the well as
pumping commences; it dies down in time exponentially and this represents the
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delay of the transitional process of reestablishing equilibrium in time. The
downward variable movement of water in the vicinity of the well resulting from
this discontinuity is proportional to the difference between the gradually
falling water table and the average head and is a cause of the slow draining of
the unconfined aquifer. The contribution of the unsaturated zone of the aquifer
in the process of slow drainage is usually of minor importance and subordinate
as far as most drainage problems are concerned. Experimental verification and
model design are presented.
72-73:04B-014
TRANSIENT FLOW TO FINITE WELL IN UNCONFINED AQUIFER,
Clever, R. M., Catton, I., and Perrine, R. L.
California University, Los Angelos, School of Engineering and Applied Science.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
99, No. HY3, Paper 9611, p 485-494, March 1973. 7 fig, 5 ref.
Descriptors: *Unsteady flow, *Groundwater movement, *Water table, *Equations,
Water yield. Drawdown, Withdrawal, Numerical analysis. Water wells. Mathematical
studies.
The problem of nonsteady radial flow toward a finite well in an unconfined
aquifer is solved by a form of the Galerkin method. The equations are reduced
to a set of coupled nonlinear ordinary differential equations in the time-
dependent Galerkin coefficients, with a constraint equation due to the nonlinear
well bore boundary condition. These are solved numerically by the Adams method
for a range of forcing. An eight term, approximation proves sufficient to yield
good results for the trial functions used. Where comparison is possible,
there is good agreement with other results and other solution methods. Response
of the flow system depends strongly on the parameters characterizing the aqui-
fer. Time to maximum drawdown at the well is very sensitive to production
rate and well radius. A similarity transformation for this problem, with a
singularity at r+0, frequently appears. Retransformation to remove the singu-
larity yields a more thorough understanding of the range of validity of the
solution.
72-73:04B-015
UNSTEADY FLOW TOWARD AN ARTESIAN WELL,
Huang, Y. H.
Kentucky University, Lexington, Department of Civil Engineering.
Water Resources Research, Vol. 9, No. 2, p 426-433, April 1973. 6 fig, 1 tab,
7 ref.
Descriptors: *Finite element analysis, *Unsteady flow, *Artesian wells, *Draw-
down, Hydraulic models, Computer programs, Groundwater movement, Artesian aqui-
fers.
Unsteady drawdown around an artesian well may be calculated using a finite
element method programmed for a high-speed computer. On the basis of assump-
tions that the well has a finite radius and that the discharge from a partially
penetrating well is not uniform along the well bore, numerical solutions for
various well penetrations are presented and compared with the experimental
measurements from a sand model. The numerical solutions check reasonably
with the experimental measurements.
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72-73:04B-016
ANALYSIS OF SEEPAGE INTO GROUNDWATER SYSTEM,
Abiodun, A. A.
Ife University (Nigeria), Department of Agricultural Engineering.
Journal of the Hydraulics Division, American'Society of Civil Engineers, Vol.
99, No. HY7, p 1203-1208, July 1973. 8 fig, 7 ref, append.
Descriptors: *Seepage, *Recharge, *Groundwater movement, Infiltration, Canal
seepage, Artificial recharge.
Analytical methods were developed to simulate seepage into a groundwater system
from a range of geometries. The solutions to such problems might find practical
application in situations where subsurface lateral distribution of seepage
flows is to be restricted and also in cases where porous medium that is to be
replenished is overlain by a fairly thin impermeable layer. The particular
case chosen is that of seepage through a channel with impervious side walls
and permeable bottom. The driving force of the flow system is the force of
gravity and the flow is two-dimensional. The seepage flows are steady and
fully saturated, taking place in an isotropic, homogeneous, porous medium,
and Darcy's Law is applicable. The solution to this problem was obtained
through the application of the hodograph technique.
72-73:046-017
PERFORMANCE OF A TILE DRAINAGE SYSTEM: AN EVALUATION OF A TILE DESIGN AND
MANAGEMENT,
Perrier, E. R., MacKenzie, A. J., Grass, L. B., and Shull, H. H.
United States Department of Agriculture, Urbana, Illinois.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 3, p 440-444, May-June, 1972. 6 fig, 6 tab, 15 ref.
(See 72-73:02G-030)
72-73:04B-018
CAPILLARY PROPERTIES OF SOILS - INFLUENCE UPON SPECIFIC YIELD,
Duke, H. R.
United States Department of Agriculture, Fort Collins, Colorado.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 4,
p 6880691, July-August, 1972. 6 fig, 2 tab, 9 ref.
(See 72-73:02F-061)
72-73:04B-019
APPLICATION OF MONTE CARLO METHOD TO SOIL WATER MOVEMENT,
Shih, S. F., and Kriz, G. J.
North Carolina State University, Raleigh.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 5, p 897-901. September-October, 1972. 5 fig, 4 tab, 8 ref.
(See 72-73:026-040)
72-73:04B-020
WATER-MANAGEMENT PROBLEMS RELATED TO GROUNDWATER RIGHTS IN THE SOUTHWEST,
Thomas, H. E.
United States Geological Survey, Menlow Park, California.
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Water Resources Bulletin, Vol. 8, No. 1, p 110-117, February, 1972. 27 ref.
Descriptors: *Water law, *Water rights, *Groundwater, Conjunctive use, Ground-
water availability, Groundwater resources, Water supply, Water utilization,
Texas, New Mexico, Arizona, California.
Brief summaries of the systems of underground water rights for the states of
Texas, Arizona, New Mexico and California are presented. Numerous references
on the subject are listed.
72-73:04B-021
MEASUREMENT OF UNSATURATED HYDRAULIC CONDUCTIVITY BY THE CONSTANT OUTFLOW
METHOD,
Overman, A. R., and West, H. M.
Florida University, Gainesville.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 6, p 1110-1111, November-December, 1972. 6 fig, 4 ref.
(See 72-73:020-042)
72-73:04B-022
WATER TABLE AND SOIL MOISTURE PROBABILITIES WITH TILE DRAINAGE,
Young, T. C., and Ligon, J. T.
Clemson University, Clemson, South Carolina.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 3, p 448-451, May-June, 1972. 8'fig, 13 ref.
(See 72-73:020-043)
72-73:04B-023
TENSIOMETER-PRESSURE TRANSDUCER SYSTEM FOR STUDYING UNSTEADY FLOW THROUGH
SOILS,
Fitzsimmons, D. W., and Young, N. C.
Idaho University, Moscow.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 2, p 272-275, March-April, 1972. 6 fig, 10 ref.
(See 72-73:020-045)
72-73:04B-024
MODELLING A GROUNDWATER AQUIFER IN THE GRAND PRAIRIE OF ARKANSAS,
Griffis, C. L.
Arkansas University, Fayetteville.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 2, p 261-263, March-April, 1972. 6 fig, 5 ref.
(See 72-73:02F-066)
72-73:048-025
TENSIOMETER USE IN SHALLOW GROUND-WATER STUDIES,
Richards, S. J., Willardson, L. S., Davis, S., and Spencer, J. R.
Soil Physicist, Riverside, California.
Journal of the Irrigation and Drainage Division, American Society of Civil
245
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Engineers, Vol. 99, No. IR4, p 457-464, December, 1973. 7 fig, 7 ref.
(See 72-73:02F-068)
72-73:046-026
SIMULATION OP POST-IRRIGATION MOISTURE MOVEMENT,
Molz, P. J.
Auburn University, Auburn, Alabama.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR4, p 523-532, December, 1972. 9 fig, 1 tab, 12 ref.
(See 72-73:020-071)
72-73:04B-027
PREFABRICATED FILTER-FIN FOR SUBSURFACE DRAINS,
Healy, K. A., and Long, R. P.
Connecticut University, Storrs.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR4, p 543-552, December, 1972. 5 fig, 1 tab, 5 ref.
(See 72-73:020-072)
72-73:04B-028
SOLUTIONS FOR LATERAL OUTFLOW IN PERFORATED CONDUITS,
Berlamont, J., and Van der Beken, A.
State University of Ghent, Department of Civil Engineering, Ghent, Belgium.
Journal of the Hydraulics Division, American Society of Civil Engineers,
Vol. 99, No. HY9, p 1531-1549, September, 1973. 11 fig, 3 tab, 17 ref.
(See 72-73:04A-037)
72-73:04B-029
UNSTEADY FLOW TO BOTTOM DRAIN IN BOUNDED AQUIFER,
Krizek, R. J., Soriano, A., and Gyuk, I.
Northwestern University, Evanston, Illinois.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 99, No. IR2, p 169-182, June, 1973. 6 fig, 11 ref.
(See 72-73:02F-079)
72-73:04B-030
SALINIZATION OF GROUNDWATER IN ARID ZONES,
Barica, J.
Fisheries Research Board of Canada, Winnipeg (Manitoba), Freshwater Institute.
Water Research, Vol. 6, No. 8, p 925-933, August, 1972. 6 fig, 3 tab, 13 ref.
Descriptors: *Water pollution, *Saltation, *Ion transport, *Water quality,
*Saline water intrusion, *Saline water-freshwater interfaces, Saline water,
Groundwater, Arid lands, Environmental effects. Irrigation effects, Ground-
water recharge, Salinity, Salts.
Identifiers: Middle East.
Natural pollution of surface and groundwaters by inorganic salts (mostly
chlorides and sulphates of Na, Mg and Ca) in arid zones is a consequence of the
246
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dry climate and the extensive irrigation practices in agriculture. Salts,
accumulated in the soil profile after evaporation of the water phase, are
redissolved either by fluctuation of shallow groundwater or leached down by
fresh irrigation water applied on the soil surface. This results in a contin-
uous increase in groundwater salinity and deterioration of its quality. Two
specific cases, typical of arid regions in the Middle East, are considered:
(1) shallow groundwaters of extremely high water tables (0.5-2.0 m) in alluviums
of large rivers (Tigris and Ephrates), and (b) deeper groundwaters (5-16 m)
in desert areas with nonsaline sandy soils of high permeability (Saudi Arabian
Plateau). In alluvial regions, groundwaters with a total dissolved solids
concentration as high as 46,000 tng/1 can be found. In desert oasis areas,
layering of relatively fresh water (TDS 500-3500 mg/1) above the saline ground-
water (TDS 7000-12,000 mg/1) can occur. Vertical distribution of groundwater
quality within the same aquifer shows pronounced zonation. Methods of water
salination control and utilization of saline water resources to supplement
the existing water supplies in arid countries are discussed.
247
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Section XX
WATER QUANTITY MANAGEMENT AND CONTROL
EFFECTS ON WATER OF MAN'S NON-WATER ACTIVITIES (Group 04C)
72-73:04C-001
SALTS IN IRRIGATION DRAINAGE WATERS: I. EFFECTS OF IRRIGATION WATER COMPOSI-
TION, LEACHING FRACTION, AND TIME YEAR ON THE SALT COMPOSITIONS OF IRRIGATION
DRAINAGE WATERS,
Rhoades, J. D., Ingvalson, R. D., Tucker, J. M., and Clark, M.
Agricultural Research Service, Riverside, California, Salinity Laboratory.
Soil Science Society of America Proceedings, Vol. 37, No. 5, p 770-774, Septem-
ber-October 1973. 6 tab, 13 ref.
Descriptors: *Leaching, *Return flow, *Water pollution sources, Lysimeters,
Water quality. Water chemistry, Salts, Alfalfa, Irrigation practices, Soil
chemistry.
The compositions of percolated drainage waters resulting from the use of eight
synthetic river waters of the Western USA under alfalfa production in a controll-
ed lysimeter experiment were studied. The compositions are affected by the
composition of the river water used for irrigation, the fraction of applied
water that appeared as drainage water, the presence or absence of soil CaC03,
whether or not the drainage water is open to the atmosphere, and the time of
year.
248
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Section XXI
WATER QUANTITY MANAGEMENT AND CONTROL
WATERSHED PROTECTION,(Group 04D)
72-73:040-001
WATERSHED MANAGEMENT: A SYSTEMS APPROACH,
Eisel, L. M.
Harvard University, Cambridge, Massachusetts, Division of Engineering and
Applied Physics.
Water Resources Research, Vol. 8, No. 2, p 326-338, April 1972. 6 fig, 2 tab,
19 ref.
Descriptors: *Watershed management, *Irrigation water, *Environmental control,
*Decision making, *Systems analysis, Mathematical models, Stochastic processes,
Recreation demand. Forest management. Range management, Risks, Hydrologic
cycle, Streamflow, Surface runoff, River flow, Sedimentation, Reservoir,
Ecosystems, Wildlife.
Identifiers: *Water resource system, Chance constraints, Wildlands, Western
United States.
A systems approach is developed to determine the type and extent of land use
management activities in wildland areas. A chance constrained programming
model is applied to a hypothetical watershed in order to investigate the effects
of risk and uncertainty on land use management decisions. The model solution
indicates that risk and uncertainty associated with the system of physical and
economic parameters can significantly affect land use management policy-making.
The solution also indicates that forest management practices to increase
streamflows may have only a minimal effect on the design and operation of
downstream reservoirs, and that future outdoor recreational demand and benefits
are important factors to consider in the arrangement of land use management
activities.
72-73:040-002
INFILTRATION, HYDRAULIC CONDUCTIVITY, AND RESISTANCE TO WATER-DROP IMPACT OF
CLOD BEDS AS AFFECTED BY CHEMICAL TREATMENT,
Gabriels, D. M., Moldenhauer, W. C., and Kirkham, D.
Iowa State University, Ames, Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 37, No. 4, p 634-637, July-
August 1973. 4 tab, 15 ref.
Descriptors: *Infiltration, *Soil erosion, *Impact (Rainfall), *Erosion
control, *Soil treatment, Soil structure, Soil sealants. Soil stability. Water
proofing, Wetting, Wettability.
Identifiers: Soil conditioners.
To test the effectiveness of surface treatments in preventing erosion during
rainfall, chemicals and bitumen were sprayed on large dry surface clods (8 to
20 mm) and small surface clods (2 to 8 mm) of a Clarion loam. The small clods
were initially wetted with 15% water on a soil weight basis and mixed with
bitumen emulsions. The large and small clods were subjected to a 6.35-cm-per-
hour simulated rainfall. Simultaneously with the measurements of infiltration
rate, determinations were made of the starting time for initial runoff, energy
needed to initiate runoff, runoff rate, total soil loss, and final soil loss
rate. Most of the soil conditioners on large clods kept the infiltration rate
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high and prevented runoff on a 9% slope. Polyvinyl alcohol and polyacrylamide
prevented any soil loss during 90 min. Surface applications with bitumen emul-
sions were also highly effective in preventing erosion of large clods but were
less effective for small clods. When the bitumen emulsions were mixed with the
small clods, the saturated hydraulic conductivity was very high. The infiltra-
tion rate was low because water would not enter the clod bed and stable clods
were carried in the runoff water.
72-73:04D-003
EFFECT OF LONG-TERM MANAGEMENT ON PHYSICAL AND CHEMICAL PROPERTIES OF THE
COSHOCTON WATERSHED SOILS,
Edwards, W. M., McGuiness, J. L., Van Doren, D. M., Jr., Hall, G. F., and
Kelley, G. E.
United States Department of Agriculture, Agricultural Research Service, North
Appalachian Experimental Watershed, Coshocton, Ohio.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 927-930,
November-December, 1973. 5 tab, 22 ref.
Descriptors: *Water supply development, *Soil conservation, Water conservation,
Runoff, Fertility, Erosion control, Water pollution sources.
After 30 years of differential treatment, 0.7- to 3.2-ha watersheds in improved
management had higher crop yields and less runoff and erosion than watersheds
under prevailing management. Soil samples were taken from the topsoils,
plowsoles, and B horizons of the watersheds to determine the effect of such
management on soil physical and chemical characteristics. Large changes in
chemical characteristics resulted from the higher fertilization associated with
improved management but the changes generally did not persist below the
topsoil layer. Measurable differences in physical characteristics of the water-
shed soils were slight and were confined to the topsoil layer. Differences
in crop yield and hydrologic performance are attributed to fertilization, crop
growth, and tillage differences associated with the two levels of management.
72-73:040-004
HYDROLOGIC AND WATERSHED MODELING FOR. REGULATING WATER QUALITY,
Kbnrad, J. G., and Cain, J. M.
Natural Resources Department, Water Resources Management Section, Madison,
Wisconsin.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 3,
p 580-581, May-June, 1973. 4 ref.
Descriptors: ^Computer models, ^Mathematical models, Watershed management,
Water quality, Hydrology.
A state-of-the-art summary is presented. The opinions of the authors as to
where modeling is going are also listed.
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Section XXII
WATER QUALITY MANAGEMENT AND PROTECTION
IDENTIFICATION OF POLLUTANTS (Group 05A)
72-73:05A-001
USE OF X-RAY FLUORESCENCE TO DETERMINE TRACE METALS IN WATER RESOURCES,
Blasius, M. B., Kerkhoff, S. J., Wright, R. S., and Cothern, C. R.
Dayton University, Ohio, Department of Physics.
Water Resources Bulletin, Vol. 8, No. 4, p 704-714, August 1972. 11 fig,
1 tab, 38 ref.
Descriptors: *Trace elements, *Water analysis, *X-ray fluorescence, X-ray
analysis, Fluorescence, Sampling, Water chemistry, Ion exchange, Water quality.
Pollutant identification.
Identifiers: Ion exchange filter paper.
The X-ray fluorescence method may be used to analyze trace metals collected
in particulate form on filter papers and from the ionic state by ion exchange
filter papers. The samples are prepared by allowing water to pass through
these filter papers. The procedures necessary for using the X-ray fluorescence
method are described. A number of samples were taken from the Great Miami
River in Dayton, Ohio over one year, showing the presence of Ca, Ti, Cr, Fe,
Cu, Zn, Sr, and Cd. Elements in the periodic table between Ti and Cs were
detectable to a sensitivity limit of the order of 30 ppb for metals in the
particulate form and 0.4 ppm for metals in the ionic form.
72-73:05A-002
SUITABILITY OF FREEZING AS A METHOD OF PRESERVING RUNOFF SAMPLES FOR ANALYSIS
OF SOLUBLE PHOSPHATE,
Nelson, D. W., and Romkens, M. J. M.
Purdue University, Lafayette, Indiana, Department of Agronomy.
Journal of Environmental Quality, Vol. 1, No. 3, p 323-324, July-September,
1972. 2 tab, 8 ref.
Descriptors: *Phosphates, *Storm runoff, *Sampling, *Freezing, Water pollution
sources, Water pollution control. Water quality control, Pollutant identifica-
tion, Sediments.
Identifiers: *Orthophosphates.
Slow freezing of surface runoff samples decreased the levels of soluble
orthophosphate in the water phase by 2% to 21%', however, low temperature
storage at 2C for 3 days or freezing of the water phase after sediment removal
did not change the orthophosphate concentrations. After it was discovered that
rapid freezing also resulted in a decrease in orthophosphate concentration,
it was concluded that freezing is a poor method to be used in this instance
unless the sediment is removed before freezing.
72-73:05A-003
VACUUM EXTRACTORS TO ASSESS DEEP PERCOLATION LOSSES AND CHEMICAL CONSTITUENTS
OF SOIL WATER,
Duke, H. R., and Haise, H. R.
United States Department of Agriculture, Fort Collins, Colorado.
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Soil Science Society of America Proceedings, Vol. 37, No. 6, p 963-964,
November-December, 1973. 3 fig.
(See 72-73:020-114)
72-73:05A-004
REMOVAL OF METAL IONS BY SOIL,
Wentink, G. R., and Etzel, J. E.
Greeley and Hansen, Chicago, Illinois.
Journal Water Pollution Control Federation, Vol. 44, No. 8, p 1561-1574, August,
1972. 2 fig, 14 tab, 4 ref.
Descriptors: *Soils, *Heavy metals, Waste water treatment, *Cation exchange,
Ions, Industrial wastes, Chromium, Copper, Zinc, Ion exchange, Clays, Sulfates,
Sampling, Soil types, Leaching, Leachate, Loam, Flame photometry. Methodology.
Identifiers: *Metal plating wastes, *Pollutant removal, Venoclysis apparatus,
Sodium saturation. Atomic absorption spectrophotometry, Ion exchange capacity.
Ion exchange methods in removing metal plating wastes using different types of
soil were investigated. Chrome, copper, and zinc in sulfate forms were chosen
as the heavy metal ions for study. Solutions of these compounds were added to
samples of three soil types: Xenia silt loam, Chalmers silty clay loam, and
Elston loam by introducing them at the top of the soil column at a low hydraulic
rate using a venoclysis apparatus. Testing to determine cation exchange capa-
city was accomplished by the sodium saturation method whereby exchange sites
in the soil sample are saturated with sodium and the sodium ions are replaced
with ammonia ions. The concentration of recovered sodium is measured by flame
photometry and the results are expressed in terms of me/100 g of oven-dry soil.
The technique was modified for use on soil containing the test ions with
metal ion concentrations measured by atomic absorption methods. Metal ion
removal in the three sample types was accomplished by an ion exchange mechanism
with exchange capacity increasing with clay mineral content. Chrome in con-
centrations up to 300 mg/1 could be removed completely in all three soils,
so could copper a fter an initial conditioning period. Zinc removal was accomp-
lished at efficiency rates of not less than 99.7 percent. It was also found
that regeneration of all three soil types was possible.
72-73:05A-005
AUTOMATED FLUOROMETRIC METHOD FOR DETERMINATION OF BORON IN WATERS, DETERGENTS
AND SEWAGE EFFLUENTS,
Afghan, B. K., Goulden, P. D., and Ryan, J. F.
Department of Energy, Mines and Resources, Burlington (Ontario). Canada Center
for Inland Waters.
Water Research, Vol. 6, No. 12, p 1475-1485, December 1972. 6 fig, 4 tab,
10 ref.
Descriptors: *Boron, *Pollutant identification, *Water analysis, *Chemical
analysis, *Sewage effluents, *Methodology, *Detergents, Automation, Chemical
reactions. Snow, Ions, Organic compounds.
Identifiers: Chemical interference, 4'-chloro-2-hydroxy-4-methoxybenzophenone,
Detection limits. Boric acid, Borax, Sodium perborate, Tetraphenyl boron.
An automated method for the determination of boron in natural waters, deter-
gents and sewage effluents is described. The method is based on the reaction
of 4'-chloro-2-hydroxy-4 methoxybenzophenone (CHMB) with boron to produce
fluorescent species, in a 90 percent sulfuric acid medium. The method has been
252
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made specific to remove any interferences from all major and minor ions and
other organic compounds normally present in water. The method is capable of
measuring different chemical forms of boron such as boric acid, borax, sodium
perborate and tetraphenyl boron. The method analyzes 10 samples per hour,
in the 5-100 ppb boron range. The rate of sample analysis can be increased to
20 per hour at higher concentration ranges. The limit of detection is 1 ppb
boron.
253
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Section XXIII
WATER QUALITY MANAGEMENT AND PROTECTION
SOURCES OP PULLUTION (Group 05B)
72-73:05B-001
NITRATE IN DEEP SOIL PROFILES IN RELATION TO FERTILIZER RATES AND LEACHING
VOLUME,
Pratt, P.F., Jones, W.W., and Hunsaker, V.E.
California University, Riverside.
Journal of Environmental Quality, Vol 1, No 1, p 97-102, January-March 1972.
5 fig, 6 tab, 8 ref.
Descriptors: *Nitrates, *Fertilizers, *Leaching, *Soil water movement,
*Path of pollutants, Groundwater movement, Denitrification, Unsaturated flow.
The NO3 concentration in saturation extracts and soil solutions was deter-
mined in 30-m profiles in six treatments of a long-term fertility trial with
citrus and in four commercial citrus groves in which the depth of sampling
was 15 m or to the top of the water table. Drainage volumes and excess N
in the soil, calculated as N input minus crop removal, provided a reasonable
estimate of the N03 concentration of water in the unsaturated zone in open-
porous soils when inputs were about 150 kg/ha per year. However, at higher
rates of inputs to porous soils or at low rates with soils with profiles which
had to be assumed to obtain a reasonable N balance. Calculated transit
times for water to move 30 in in the unsaturated zone varied from 12 to 49
years.
72-73:O5B-002
DENITRIFICATION AND NITRATE REDUCTION IN WISCONSIN LAKE SEDIMENTS,
Chen, R.L., Keeney, D.R., Graetz, D.A., and Holding, A.J.
Wisconsin University, Madison.
Journal of Environmental Quality, Vol 1, No 2, p 158-162, April-June, 1972.
5 fig, 2 tab, 21 ref.
Descriptors: *Nitrification, *Denitrification, *Nitrates, *Nutrient removal,
*Water pollution sources. Water quality, Laboratory tests, Sediments, Ground-
water , Eutrophication.
Identifiers: *Seepage lakes.
Laboratory and field experiments were conducted to investigate the fate of 15
N labelled NO3-N in Wisconsin lake sediment-water systems. Approximately
90% of the added NO3-N disappeared from a calcareous sediment compared to
about 40% from a non-calcareous sediment after 48 hours when incubated under
helium; this was a laboratory study result. The recovery of significant
amounts of NH4-N particularly in calcareous sediment indicated that immobo-
lized N was subject to rapid mineralization Nitrate-15 N not accounted for
was assumed lost through denitrification. In field studies 15NO3-N added to
calcareous sediment samples and returned to the lake bottom in wide mouth
plastic bottles disappeared within 4 days. About 37% of the added NO3-N
was in the organic and NH4-N fractions after 4 days while the remaining 63%
was lost through denitrification. These data illustrate that denitrification
and nitrate reduction in sediments receiving nitrate from groundwaters must
be evaluated in calculating nitrogen budgets of seepage lakes.
72-73:058-003
EFFECTS OF SEDIMENT ON WATER QUALITY,
Stall, J.B.
Illinois State Water Survey, Urbana.
Journal of Environmental Quality, Vol 1, No 4, p 353-360, October-December
1972. 5 fig, 4 tab, 28 ref.
254
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Descriptors: *Sediment load, *Turbidity, *Sediment yield, *Illinois, *Water
pollution effects, Water pollution, Path of pollutants. Soil erosion, Water
chemistry, Water quality, Urbanization, Erosion control, Sediment control,
Turbidity.
Flowing water in a stream carries sediment which is considered a pollutant
because it interferes with many uses of water. Other pollutants in the water
may be attached to or greatly affected by the sediment. The ultimate source
of most sediment is soil loss from sheet erosion. Soil loss may be as high as
100 metric tons/ha per year on a steep, loose, cropped soil, or on any soil
left bare during construction activity. Nearly level land in Illinois may lose
10 tons/ha per year regularly. Rivers carry a load of suspended sediment as
a part of their total energy balance. If the suspended sediment load of a
river is reduced, the stream will erode its bed or banks to pick up sediment
to re-establish its energy balance. Traditional soil conservation measures
will reduce soil loss from the farmer's field; this will also reduce sediment
yield to a downstream reservoir. Reductions are often 70% to 90%.
72-73:058-004
DDT AND TOXAPHENE MOVEMENT IN SURFACE WATER FROM COTTON PLOTS,
Bradley, jr., J.R., sheets, T.J., and Jackson, M.D.
North Carolina State University, Raleigh.
Journal of Environmental Quality, Vol 1, No 1, p 102-105, January-March 1972.
1 fig, 3 tab, 15 ref.
Descriptors: *Runoff, *Sediment, *Pesticide movement, *Pesticide pollution,
*Water pollution sources, Chlorinated hydrocarbon pesticides, Pesticide resi-
dues, Path of pollutants, Farm wastes. North Carolina.
When 13.4 kg/ha of DDT were applied to cotton (Gossypium hirsutum L.) during
the 1969 growing season, 2.83% was found in natural runoff between July 11,
1969 and January 5, 1970. About 96% of the DDT in runoff was associated with
suspended sediment. Of 26.8 kg/ha of toxaphene applied, 0.36% was detected
in runoff, and 75% of the toxaphene in runoff was in the sediment fraction.
When DDT and toxaphene were applied to the same plot (13.4 and 26.8 kg/ha,
respectively, over the season) only 1.03% of the DDT was found in runoff, and
the percentage for toxaphene was 0.61. A much greater percentage of DDT and
toxaphene remained as soil residues than was found in runoff, but a high
percentage of the pesticides applied was not recovered. Residues of DDT in
water from a small pond within one experimental watershed ranged from <0.35 ppb
before spraying to 65 ppb about midseason.
72-73:05B-005
INFLUENCE OF AGRICULTURAL PRACTICES ON WATER QUALITY IN NEBRASKA: A SURVEY OF
STREAMS, GROUNDWATER, AND PRECIPITATION,
Olson, R.A., Seim, E.G., and Muir, J.
Nebraska University, Lincoln.
Water Resources Bulletin, Vol 9, No 2, p 301-311, April 1973. 3 fig, 2 tab,
11 ref.
Descriptors: *Water pollution sources, *Nebraska, *Fertilizers, *Irrigation
practices, Farm wastes, Path of pollutants, Water quality, Nitrates, Phosphates,
Nutrients, Water pollution effects, Groundwater, Surface waters.
Where nutrient levels of streams in Nebraska are elevated, the cause is usually
industrial, sewage or livestock waste intrusion, and not crop production
practices. The only significant quantity of nutrient N and P induced by
cultivation is that accompanying sediments from eroded fields. The P content
of Nebraska groundwater has remained essentially constant during the past
10 years while average NO3 has increased slightly, in a period during which
farmer fertilizer use quadrupled. During the same time, irrigation acreage
has increased by 50%, livestock numbers by 30%, with corresponding growth in
human population and attendant industries. Irrigation practice has contri-
buted more than any other factor to the small increase in groundwater N03.
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72-73:05B-006
GROUNDWATER QUALITY IN THE CORTARO AREA NORTHWEST OF TUCSON, ARIZONA,
Schmidt, K.D.
Water Resources Bulletin, Vol 9, No 3, p 598-606, June 1973. 2 fig, 3 tab,
12 ref.
Descriptors: *Water quality, *Groundwater, *Path of pollutants, *Arizona,
*Waste disposal, Sewage disposal, Infiltration, Nitrates, Coliforms, Alluvium,
Maienclaves, Hydrogeology, Groundwater movement.
Identifiers: *Tucson (Ariz).
The Cortaro area is used for disposal of much of the liquid waste from the
city of Tucson, Arizona. In the past, more than one-half of the sewage
effluent was used for crop irrigation. However, since 1970 virtually all of
the sewage effluent has been percolated in the normally dry Santa Cruz River
channel. Nitrate and chloride contents are monitored in water samples from
about 20 large-capacity irrigation wells. Contents and seasonal trends for
these constituents are closely related to the disposal of sewage effluent.
Water quality problems other than nitrate include total dissolved solids,
boron, coliform, and lead. High lead contents in the area appear to be a
natural phenomenon and the coliform contents are related to poor well con-
struction. The other quality problems are primarily caused by sewage efflu-
ent.
72-73:058-007
MICROBIOLOGICAL QUALITY OF SUBSURFACE DRAINAGE WATER FROM IRRIGATED AGRICUL-
TURAL LAND,
Smith, J.H., Douglas, C.L., and Bondurant, J.A.
Agricultural Research Service, Kimberly, Idaho, Snake River Conservation
Research Center.
Journal of Environmental Quality, Vol 1, No 3, p 308-311, July-September,
1972. 1 fig, 4 tab, 8 ref.
Descriptors: *Irrigation water, Groundwater, *Bacteria, *Coliforms, Water
pollution, Groundwater movement, Water pollution sources, Water pollution
control. Water quality, *Idaho, Path of pollutants.
Identifiers: Fecal coliforms.
Irrigation and subsurface drainage waters were sampled from a district in
southern Idaho and evaluated for bacteriological quality. The sampling took
place in the summer of 1969 at two week intervals. From 140 to 3,300 coli-
forms per 100 ml were contained in the diverted irrigation water. However,
86% of the subsurface drainage samples contained 5 or fewer coliforms per 100
ml. Apparently percolation through the soil improved the water quality almost
to domestic water standards.
72-73:053-008
PESTICIDE-SEDIMENT-WATER INTERACTIONS,
Pionke, H.B. and Chesters, G.
Agricultural Research Service, Chickasha, Oklahoma, Southern Great Plains
Watershed Research Center.
Journal of Environmental Quality, Vol 2, No 1, p 29-45, January-March, 1973.
9 fig, 1 tab, 150 ref.
Descriptors: *Pesticides, *Sediments, Aquatic soils. Water pollution sources,
Limnology, Aquatic plants, Balance of nature, *Sediment-water interfaces, *Lake
sediments, ^Reviews.
Pesticide-sediment-water interactions occurring within a watershed and the
associated aquatic system are reviewed regarding their impact on the distri-
bution and persistence of pesticides in recipient lakes. Pesticidal persis-
tence on the watershed is discussed initially because the aquatic residue
hazard depends largely on the persistence of soil-applied pesticides.
Mechanisms of transport from field to aquatic system are reviewed for those
compounds not degraded rapidly to nontoxic derivatives. Pesticide transport
through the atmosphere, ground water, and surface runoff is traced with
256
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particular emphasis on application-associated losses and transport effect on
initial pesticide distribution and concentration in the aquatic system. Field
and plot studies evaluating pesticide losses in runoff are summarized. Within
the aquatic system, limnological, sediment and water characteristics potentially
alter the distribution of adsorbed pesticide between water and associated sedi-
ment within the lake. Specifically, the effects of pH, lake stratification,
characteristics and content of sediment organic matter and clay, and salinity
are evaluated. This review concluded with a discussion of literature on
pesticide persistence determined in simulated or natural aquatic systems and
the interactions between aquatic vegetation, sediment, and water which affect
pesticide distribution.
72-73:053-009
A STATISTICAL METHODOLOGY FOR PREDICTING THE POLLUTANTS IN A RIVER,
Nour, A. Abouel and Razek, A.
Mississippi State University, State College
Water Resources Bulletin, Vol 8, No 1, p 15-23, February 1972. 2 fig, 3 tab,
6 ref.
Descriptors: *Statictical models, *Water pollution, *Path of pollutants,
Mathematical models, Regression analysis, Water pollution sources, Water
pollution effects.
Identifiers: *Pearl River (Miss).
Accurate, reliable, and sensitive water quality prediction models may be con-
structed by dividing a natural stream into independent reaches based on physi-
cal criteria. Predicting equations of the water pollutants are obtained by
regression in a selected stream. Water quality data were gathered in the
Pearl River, which flows southwest and then turns south through the states
of Mississippi and Louisiana. This evaluation serves as guidelines to divide
the total river basin into reaches (subsystems). After subsystem assignment
a stepwase multiple regression FORTRAN program is used to regress tne poTlu-'
tants (dependent variables) for both time and space on their water cha?acter-
toof fo^^n^nt varia*>les) . The statistical approach provides a practical
tool for developing regression equations for water pollution prediction.
72-73:058-010
LINE SOURCE DISTRIBUTIONS IN TWO DIMENSIONS: APPLICATIONS TO WATER QUALITY
DlToro, D.M. '
S^^p6^00116^' Br°nv' N-Y- ^ironmental Engineering and Science Program.
? * u Resou*ces Research, Vol 8, No 6, p 1541-1546, December 1972. 2 fiq
1 tab, 9 re f. ^ '
Descriptors: *Dispersion, *Chemical degradation, *Path of pollutants, mathe-
matical models. Numerical analysis, Mixing, Biochemical oxygen demand, Dissolved
oxygen, Oxygen sag, Mass transfer, Currents (Water), Estuaries.
The steady state two-dimensional concentration distribution that results in the
horizontal plane from the continuous discharge of a concenservative substance
*n L^1 X?*1?1 bodv.of water is analyzed. The analysis is readily extended
to sequentially reacting substances, so that the solution can be applied to
^Son?a*lati°n of concentration distributions of biochemical oxygen demand
(BOD) and dissolved oxygen (DO) deficit. The resulting solutions are easily
applied by using a table and figures. A numerical example is presented to
illustrate the method. The approach is essentially the two-dimensional analog
of the steady state analysis conventionally applied to a one-dimensional
estuary. The physical situation is given as an infinite vertically well-mixed
body of water, which may be tidal, for which the predominant mass transport
mechanism is dispersion. A uniform line source of mass decays following
first order kinetics in a two-dimensional dispersive field.
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72-73:058-011
ABSORPTION OF WATER BY A SOIL FROM A CIRCULAR CYLINDRICAL SOURCE,
Singh, R.
California State University, San Jose, Dept. of Civil Engineering and Applied
Mechanics,
Water Resources Research, Vol 8, No 6, p 1581-1589, December 1972. 4 fig, 11
ref.
Descriptors: *Path of pollutants, *Radioactive wastes, *Diffusion, *Soil
water movement, *Translocation, Equations, Radioactive waste disposal, Malen-
claves. Ion exchange, Heat flow. Mass transfer, Ion transport, Groundwater
movement.
Underground burying of radioactive liquid and solid wastes has been practiced
for years at Hanford, Oak Ridge, and other places. These highly dangerous
wastes can diffuse out in lateral directions if the containers crack due to
earthquakes and internal pressures in relatively thin confined stratum.
These situations are often characterized as the absorption of moisture by the
partially saturated soil surrounding the disposal site. This phenomenon
is governed by a nonlinear partial differential equation, subject to initial
and boundary conditions. A method of weighted residuals is applied to extract
an explicit solution, which is simple for applications. The solution is
valid for any form of the diffusivity function and can be used with any value
of initial moisture content.
72-73:058-012
FINITE ELEMENT METHOD FOR THE HYDRODYNAMIC DISPERSION EQUATION WITH MIXED
PARTIAL DERIVATIVES,
Nalluswami, M., Longenbaugh, R.A., and Sunada, D.K.
Colorado State University, Fort Collins, Dept. of Civil Engineering.
Water Resources Research, Vol 8, No 5, p 1247-1250, October 1972. 1 fig, 10
ref.
Descriptors: *Dispersion, *Groundwater movement, *Mathematical models,
*Finite element analysis. Numerical analysis, Mathematical studies, Diffusion,
Mixing, Path of pollutants, Convection.
A method was developed to extend the use of the finite element technique for
solving the two-dimensional dispersion equation. The dispersion coefficients
are treated as second order symmetric tensors. The concentration of the dis-
persing tracer is assumed to be given by a linear polynomial. By means of
variational principles a new functional was developed to include the mixed
partial derivatives resulting from the anisotropy of the dispersion coefficient.
The application of the minimization procedure and the finite element method
leads to a set of simultaneous first order linear differential equations.
72-73:058-013
REGIONAL ANALYSIS OF STREAMFLOW CHEMICAL QUALITY IN TEXAS,
Steele, T.D., and Jennings, M.E.
Geological Survey, Washington, D.C. Water Resources Div.
Water Resources Research, Vol 8, No 2, p 460-477, April 1972. 10 fig, 7 tab,
18 ref.
Descriptors: *Regional analysis, *Water quality, *Texas, *Statistical methods,
*Regression analysis, Variability, Correlation analysis, Hydrologic data,
Water chemistry. Sampling, Surface waters.
Thirty-one streamflow water quality stations in Texas, with long-term histor-
ical records ranging from 7 to 28 years, were selected for statistical analyses
of the annual mean concentrations of the major chemical constituents. A
statewide multiple regression analysis using frequency characteristics of
annual mean water quality constituents as dependent variables and selected
basin characteristics as independent variables was investigated as a means of
regionalizing information on annual water quality characteristics. For the
two different regression models investigated, a single independent variable,
generally stream discharge or average basin rainfall, explained a significant
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part of the variance of the dependent water quality variables. A real analysis
of residuals of the statewide regression models indicated two distinct regional
patterns. Correlation coefficients for the concentration-rainfall regional
models ranged from 0.80 to 0.97 and the standard errors of estimate were
between 26 and 99% of the means of the dependent variables. An analysis
of various concentraion-conductance relationships for the statewide data
also gave favorable results, and provided an alternate method for obtaining
estimates of streamflow chemical quality characteristics.
72-73:058-014
WATER POLLUTION AS AFFECTED BY STREET SALTING,
Hawkins, R.H., and Judd, J.H.
State University of New York, Syracuse. Water Resources Center
Water Resources Bulletin, Vol 8, No 6, p 1246-1252, December 1972. 1 fig,
3 tab, 12 ref.
Descriptors: Water pollution sources, *Deicers, *Salts, *Snow removal, *New
York, *Path of pollutants, Urban hydrology, Suburban areas, Roads, Highway
icing, Stratification, Density stratification, Salinity, Environmental effects,
Water pollution sources.
Identifiers: *Street salting, Road salting, Meadowbrook (NY), Syracuse (NY).
The use of salt to melt ice and snow on streets and roads has become prevalent
throughout the Northeast U.S. Several states apply as much 20 tons per lane-
mile. Eventually the salt reaches streams and lakes. In Meadowbrook, New
York, the chloride content reached a high of 11,000 ppm in December 1969.
The runoff from the watershed was emitted in several surges. Chloride concen-
trations declined with the onset of summer, but still remained high suggesting
that some of the salt applied during the past winter appeared in the summer
streamflow. Salt runoff entered a small lake, and flowed directly to the lake
bottom. The buildup of high density saline water in the lower portion of the
lake prevented complete mixing in the spring. Incomplete mixing led to
anoxic conditions in the lower lake strata. The population of benthic fauna
of the lake was changed by the flow of salt water into the lake. From a total
of 10 species of dipteran larva and oligochaetes, only 4 species remained.
72-73:05B-015
WATER QUALITY PREDICTION WITHIN AN INTERBASIN TRANSFER SYSTEM,
White, W.A., Tischler, L.F., and Austin, T.A.
Texas Water Development Board, Austin. Systems Engineering Div.
Water Resources Bulletin, Vol 8, No 3, p 483-494. June 1972. 6 fig, 7 ref.
Descriptors: *Water quality, * Inter-basin transfers, *Mathematical models,
*Texas, *Planning, Computer programs, Simulation analysis, Systems analysis,
*Model studies.
Identifiers: *Texas water plan.
A methodology for predicting the spatial and temporal levels of conservative
water quality constituents within a multibasin water resource system is pre-
sented. Dissolved solids, sulfates, and chlorides are the constituents used
during this investigation; however, any other conservative ion or mineral can
be incorporated into the simulation model. The methodology is tested on the
proposed Texas Water System. The water quality model, QNET-I, utilizes monthly
canal and river flows and reservoir storage levels calculated by the Texas
Water Development Board's systems simulation model. Discharge-concentration
relationships are developed for each source of water in the system, including
significant waste-water discharges. Reservoirs in the system are assumed to
be completely mixed with respect to conservative constituents. A mass balance
analysis is performed for each node and each month during the simulation period.
The output from the water quality simulation is a table of the concentrations
of the conservative water quality constituents at each demand point in the
system and in each reservoir and canal for every month the system is in oper-
ation. The desired quality of the water at the demand locations is used
to determine the economic utility of transporting and mixing water from various
sources.
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72-73:058-016
A HYBRID COMPUTER PROGRAM FOR PREDICTING THE CHEMICAL QUALITY OF IRRIGATION
RETURN FLOWS,
Thomas, J.L., Riley, J.P., and Israelsen, E.K.
Ohio University, Athens Dept, of Civil Engineering.
Water Resources Bulletin, Vol 8, No 5, p 922-934, October 1972. 10 fig, 10 ref.
Descriptors: *Simulation analysis, *Hybrid computers, *Computer programs,
*Return flow, *Path of pollutants, Water quality, Water pollution, Water
Management (Applied), Mathematical models, Ion exchange, Leaching, Percolation,
Calcium, Magnesium, Sodium, Sulfates, Chlorides, Bicarbonates, Irrigation water.
A hybrid computer program was developed to predict the water and salt outflow
from a river basin in which irrigation is the major user of water. The model
combines a chemical model which predicts the quality of water percolated
through a soil profile with a general hydrologic model. The chemical model con-
siders the reactions that occur in the soil, including the exchange of cal-
cium, magnesium, and sodium cations on the soil complex, and the dissolution
and precipitation of gypsum and lime. The chemical composition of the outflow
is a function of these chemical processes within the soil, plus the blending
of undiverted inflows, evaporation, transpiration, and the mixing of subsur-
face return flows with groundwater. The six common ions of western waters,
namely calcium, magnesium, sodium, sulfate, chloride, and bicarbonates were
considered in the study, total dissolved solids outflow was obtained by
addint the individual ions. The overall model operates on a monthly time
unit. The model was tested on a portion of the Little Bear River basin in
northern Utah. The model successfully simulated measured outflows of water and
each of the six ions for a 24-month period. Preliminary results indicated that
the available water supply could be used to irrigate additional land without
unduly increasing the salt outflow from the basin. With minor adjustments
the model can be applied to other hydrologic areas.
72-73:058-017
A WATER QUALITY MODEL FOR A CONJUNCTIVE SURFACE-GROUNDWATER SYSTEM: AN
OVERVIEW,
Perez, A.I., Huber, W.C., Heaney, J.P., and Pyatt, E.E.
Florida University, Gainesville. Dept. of Environmental Engineering.
Water Resources Bulletin, Vol 8, No 5, p 900-908, October 1972. 8 fig, 25 ref.
Descriptors: *Mathematical models, *Conjunctive use, *Lakes, Water pollution
sources, *Florida, Surface-groundwater relationships, Rainfall-runoff rela-
tionships, Percolation, Runoff, Leaching, Base flow, Infiltration, Water
management (Applied), Water quality, Path of pollutants, Overland flow, Soil
water movement, Groundwater movement.
Identifiers: Lake Apopka (Fla).
A mathematical model is designed to predict water quality in a surface-
groundwater system. The goal is to obtain cause and effect relationships
between pollutant sources and the ensuing concentrations at different locations
in a basin. Several programs are used to model rainfall, runoff, flow in sur-
face bodies of water, infiltration, and groundwater flow. At every time step
in the simulation, the water quantity computation are performed first.
Subsequently, the results of these computation, typically in the form of flow
velocities, are used as input to the water quality calculations. The water
quality routines involve the modeling of the associated physical, chemical, and
biological processes. Empahsis is placed on pollution in agricultural areas.
Accordingly the Lake Apopka basin in Central Florida is being used as the appli-
cation site.
72-73:058-018
NITRATE CONCENTRAIONS IN GOUNDWATER BENEATH A BEEF CATTLE FEEDLOT,
Lorimor, J.C., Mielke, L.N., Elliott, L.F., Ellis, J.R.
Agricultural Research Service, Gunnison, Colo. Soil and Water Conservation
Research Div.
Water Resources Bulletin, Vol 8, No 5, p 999-1005, October, 1972. 4 fig, 3 tab,
6 ref.
260
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Descriptors: Groundwater, Groundwater movement, Aquifer characteristics,
Nitrogen, *Nitrates, Piezometers, *Water sampling, Irrigation, Cattle, *Feed
lots, Dyes, Tracers, Transmissivity, Hydraulic gradient.
Identifiers: Nitrate-Nitrogen.
In June 1970, a groundwater sampling study was conducted in conjunction with
initiation of irrigation pumping from groundwater near a feed lot located
in east-central Nebraska. Aquifer characteristics and nitrate-nitrogen
concentrations in the water were determined. A dye injected into the water
showed that water from beneath the feedlot was being sampled at the wells
immediately outside the lot. Groundwater nitrate levels were generally
lower down-gradient from the feedlot than they were up-gradient. Nitrate
levels in the well samples were not changed significantly by the start of
irrigation pumping, although they did appear to increase slightly. Piezometer
samples did show a significant difference. Except for two samples obtained
during the pumping trial, nitrate-nitrogen was well below the Public Health
Service limit of 10 parts per million.
72-73:05B-0 19
ANNUAL CYCLE IN RIVER WATER QUALITY: A TIMES SERIES APPROACH,
Edwards, A.M.C., and Thornes, J.B.
King's Coll., London (England). Rogate Field Center
Water Resources Research, Vol 9, No 5, p 1286-1295, October 1973. 6 fig,
5 tab, 17 ref.
Descriptors: *Time series analysis, *Water quality, *Streamflow, *Path of
pollutants, Frequency analysis, Statistics, Statistical methods, Variability,
Regression analysis, Fourier analysis, Correlation analysis.
Identifiers: *River Stour (England).
Regression, spectral, and cross-spectral techniques were used to examine the
trends and periodicity in a 20-year record of weekly observations of eight
water quality variables in the River Stour, eastern England. Linear regression
shows that all except pH and carbonate hardness have significantly increased
over time. A strong annual cycle is present. Cross-spectral analysis was
used to model the relationship between the variables and the water discharge
in time. Nitrate and non-carbonate hardness are positively correlated with
discharge, whereas carbonate hardness is an inverse function.
72-73:058-020
EFFECT OF AGRICULTURAL MANAGEMENT OF WET SLOPING SOIL ON NITRATE AND PHOSPHORUS
IN SURFACE AND SUBSURFACE WATERS,
Benoit, G.R.
Agricultural Research Service, Burlington, Vt., New England Watershed
Research Center.
Water Resources Research, Vol 9, No 5, p 1296-1303, October 1973. 3 fig,
3 tab, 13 ref.
Descriptors: *Nitrates, *Phosphates, *Path of pollutants, *Water pollution
sources, *Fertilizers, Farm wastes, Runoff, Groundwater, Leaching, Infiltra-
tion, Drainage water, Subsurface drainage, Drainage practices.
Differences in nitrate and phosphate content of water from three cropping
systems were evaluated in a 12-plot study in East Franklin, Vermont, on a
poorly drained, sloping Cabot silt loam: (1) timothy, red clover, Kentucky
bluegrass hay pasture; (2) corn silage. Six plots were in alfalfa hay,
six plots were planted in corn, and the upslope area was in hay-pasture.
Soil samples were collected in the summers of 1969 and 1970 and analyzed for
total soil nitrogen. Surface and subsurface drain effluent samples from the
plots and upslope area were analyzed for nitrates and phosphates. Draining
wet sloping land may decrease total soil nitrogen; nitrate nitrogen may be
lost from organic matter breakdown in cold but unfrozen soil; nitrates but not
phosphates will move both vertically and laterally through the soil to
subsurface drains; surface runoff contains few nitrates but significant
concentrations of phosphates; and more nitrates were lost from fertilized corn
plots than from alfalfa plots or hay pasture areas.
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72-73:053-021
DISPERSION TRANSPORT OF REACTING SOLUTES IN SATURATED POROUS MEDIA: GALERKIN
METHOD APPLIED TO EQUILIBRIUM-CONTROLLED EXCHANGE IN UNIDIRECTIONAL STEADY
WATER FLOW,
Rubin, J., and James, R.V.
Geological Survey, Menlo Park, California.
Water Resources Research, Vol 9, No 5, p 1332-1356, October 1973. 7 fig, 22
ref.
Descriptors: *Dispersion, *Ion exchange, *Ion transport, *Groundwater move-
ment, Path of pollutants, Water chemistry. Mass transfer, Solutes, Chemical
reactions, Saturated flow, Translocation, Leaching, Mathematical studies,
Numerical analysis.
Identifiers: *Galerkin method.
Equations describing dispersion and ion exchange in one-dimensional transport
of solutes in saturated porous media may be solved numerically by means of
the Galerkin method. It is assumed that water flow is steady and that local
chemical equilibrium exits throughout the systems considered. No constancy
restrictions are placed on the total concentration of the dissolved ions
participating in exchange. The cases treated involve (1) homogenous or
layered systems, (2) exchange reactions with constant or concentrations
dependent selectivity coefficients, (3) binary or multicomponent exchange, and
(4) systems in which one of the exchanging ions is also involved in a
precipitation-dissolution reaction. The appraoch may be useful in analyzing
a variety of solute transport processes of hydrologic interest.
72-73:058-022
DISPERSION DURING FLOW IN POROUS MEDIA WITH BILINEAR ADSORPTION,
Gupta, S.P., and Greenkorn, R.A.
Purdue University, Lafayette, Ind. School of Chemical Engineering.
Water Resources Research, Vol 9, No 5, p 1357-1368, October 1973. 4 fig,
1 tab, 27 ref.
Descriptors: *Path of pollutants, *Dispersion, *Groundwater movement.
Numerical analysis, *Adsorption, Porous media. Farm wastes. Industrial
wastes. Fertilizers, Pesticides, Herbicides, Water pollution sources.
Major sources of pollution in underground water come from the runoff of
cattle feedlots, from runoff of fertilizers, pesticides and herbicides from
cultivated lands, and from domestic and industrial wastes. The equations for
the dispersion and adsorption of various chemicals in porous media are form-
ulated to calculate pollution movement. If a bilinear rate of adsorption
is assumed, two coupled nonlinear parabolic partial differential equations
result. The equations can be solved by the Crank-Nicolson method, which is
a stable, two-step method. Solutions for the range of variables involved
in the movement of pollutants in porous media are obtained for a one-
dimensional model.
72-73:058-023
SURFACE WATER QUALITY IS INFLUENCED BY AGRICULTURAL PRACTICES,
Holt, R.F.
Agricultural Research Service, Morris, Minn. Central Soil Conservation
Research center.
Paper No 71-740, presented at the 1971 Winter Meeting, American Society of
Agricultural Engineers, Chicago, Illinois, December 7-10, 1971. 19 p, 3
tab, 34 ref.
Descriptors: *Water quality, *Pollutants, *Water pollution, *Water pollution
sources, Farm wastes, Watershed management, Land management, Watersheds,
Soil amendments, Fertilization.
Fertilization, animal waste handling, soil amendments and cropping practices
can all influence the quality of water that runs off an agricultural water-
shed. Maintenance of high quality surface water demands the development of
practices which can minimize the nutrient, pesticide, manure, and sediment
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loading of water impoundments. The physical trapping or tying down of solid
particles can control sediment delivery but not dissolved substances. Utili-
zation of the sorptive capacity of the soil offers a mechanism for controlling
the movement of soluble contaminants into water supplies.
72-73:058-024
ADSORPTION AND TRANSPORT OF AGRICULTURAL CHEMICALS IN WATERSHEDS,
Frere, M.H.
Agricultural Research Service, Durant, Oklahoma. Water Quality Management Lab.
Paper No. 12 presented at the 1971 Winter Meeting, American Society of Agri-
cultural Engineers, Chicago, Illinois, December 7-10, 1971. 12 p, 1 fig, 12 ref.
Descriptors: *Path of pollutants, *Agricultural chemicals, Leaching, Adsorption,
Watersheds, Soil-water-plant relationships, Pollutants.
A descriptive model of the pathways of chemicals in the soil-water-plant system
is used to catalogue the properties of agricultural chemicals that are impor-
tant to their movement in watersheds. The chemical interactions dictate
the pathways to be followed while the behavior of water controls the time and
amount of movement.
72-73:056-025
PERTURBATION ANALYSIS OF THE EQUATION FOR THE TRANSPORT OF DISSOLVED SOLIDS
THROUGH POROUS MEDIA: I. LINEAR PROBLEMS,
Wooding, R.A.
Wisconsin University, Madison. Dept. of Soil Science.
Journal of Hydrology, Vol 16, No 1, p 1-15, May 1972. 4 fig, 26 ref.
Descriptors: *Groundwater movement, *Path of pollutants, *Numerical analysis,
*Ion transport, Porous media, Mixing, Diffusion, Leaching, Translocation, Ion
exchange, Water chemistry, Saline water-freshwater interfaces.
The technique of matched asymptetic expansions is applied to solute transport
in steady one-dimensional flow systems in porous slabs, membranes or columns,
assuming linear exchange equilibrium and constant diffusivity. These special
cases are studied as a preliminary to the examination of more difficult non-
linear systems. The governing dimensionless parameter is the macroscopic
Peclet number. Three cases are treated to illustrate features of the pertur-
bation technique. With a fluctuating diffusion ('back-mixing') layer at the
outlet when the input concentration is a fairly slowly varying, arbitrary
function of time, the outer problem is hyperbolic and is easily solved, while
the inner problem reduces to the solution of a set of ordinary differential
equations. With a thickening diffusion layer at a discontinuity between two
fairly slowly-varying concentration functions, the solution obtained is quali-
tatively different from that of the nonlinear case. With the arrival of a
diffusion zone (initially a concentration step) at the outlet, the solution
possesses features of a fluctuating and thickening diffusion layer. This is
a special example with analogies to a 'boundary layer within a boundary layer1,
and illustrates, in particular, a type of concentration distribution which can
be encountered in classic breakthrough experiments.
72-73:058-026
THE DETERMINATION OF DISPERSION COEFFICIENTS IN NON-HOMOGENEOUS MEDIA IN
PROBLEMS OF SALT WATER CONTAMINATION OF FRESH GROUND WATER,
Bonnier, A. and Korganoff, A.
Societe Centrale pour I1Equipment du Territoire-International, Puteaux (France).
Journal of Hydrology, Vol 16, No 1, p 39-47, May 1972. 20 ref.
Descriptors: *Saline water intrusion, *Diffusion, *Mixing, *Path of pollutants,
*Mathematical studies, Diffusivity, Dispersion, Equations, Grc-undwater move-
ment, Mathematical models.
Identifiers: *Coastal aquifers.
Salt-water contamination of fresh groundwater is one of the major problems
facing the population of coastal areas. The use of a mathematical model taking
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into consideration diffusion phenomena requires a knowledge of dispersion para-
meters which vary from one point to another in a nonhomogeneous medium. A
mathematical method for overcoming these difficulties is given.
72-73:058-027
MINERAL POLLUTION IN THE COLORADO RIVER BASIN,
Blackman, Jr., W.C., Rouse, J.V., Schillinger, G.R., and Shafer, Jr., W.H.
Environmental Protection Agency, Phoenix, Arizona, Colorado River Basin
Water Quality Control Project.
Journal Water Pollution Control Federation, Vol 45, No 7, p 1517-1557,
July 1973. 24 fig, 14 tab, 19 ref.
Descriptors: *Salinity, *Water pollution sources, *Colorado River, Irrigation
water. Leaching, Salts, Runoff, Chlorides, Bicarbonates.
Concentrations of total dissolved solids (salinity) in Colorado River basin
streams are a major problem for lower basin water users. Salinity concentra-
tions in unregulated streams of the basin comprise two distinct populations
that are grouped into base flow months and runoff months. Statistically
significant increases in salinity have occurred with increasing water use, and
in downstream progression. Upper basin salt load contributions are: runoff,
52 percent; irrigated agriculture, 37 percent; natural point sources and
flowing wells, 9 percent; and municipal and industrial, 7 percent. Lower
basin contributors are: upper basin inflow, 72 percent; natural point sources,
15 percent; irrigated agriculture, 9 percent; runoff, 4 percent, and municipal
and industrial,'less than 1 percent. Salt yields from irrigated lands range
from near 0 to 8.5 tons/yr/acre. Greatest yields are from irrigation of
and runoff from lands underlain by Mancos shale and Tertiary lake beds.
Headwater areas yield predominantly calcium bicarbonate waters. Saline sedi-
ments in lower valleys cause waters to become predominantly high in sodium
calcium sulfate ions.
72-73:058-028
FACTORS AFFECTING THE PERCOLATION TEST,
Healy, K.A. and Laak, R.
Connecticut Univ., Storrs. Dept of Civil Engineering.
Journal Water Pollution Control Federation, Vol 45, No 7, p 1508-1516,
July 1973. 10 fig, 2 tab, 5 ref.
Descriptors: *Infiltration, *Percolation, *Septic tanks, Soil disposal
fields.
Identifiers: *Percolation tests.
A mathematical analysis of the percolation test is presented with both cap-
illary and gravity flow potentials considered. A relation between percolation
rate, capillarity, hole shape, and permeability is developed. Laboratory
percolation tests qualitatively support the analysis. Field percolation
tests show no correlation between percolation rate, permeability, or position
of the water table. The percolation test seems to be an unreliable method of
determining the water absorption capability of a soil deposit.
72-73:058-029
NITROGEN AND PHOSPHORUS CONTENT OF WATER FROM TILE DRAINS AT TWO LEVELS OF
MANAGEMENT AND FERTILIZATION,
Zwerman, P.J., Greweling, T., Klausner, S.D., and Lathwell, D.J.
Cornell Univ., Ithaca, N.Y., Dept. of Agronomy.
Soil Science Society of America Proceedings, Vol 36, p 134-137, 1972. 1 fig,
7 tab, 10 ref.
Descriptors: *Drainage water, *Fertilization, Water pollution sources,
*Leaching, *Nitrogen, *Phosphorus, Tile drains, Agriculture, Nitrates,
Ammonia, Phosphates, Agricultural runoff, Soils.
Identifiers: Lima-Kendaia soil.
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Since excessive nitrogen and phosphorus are a major cause of increased growth
of undesirable aquatic vegetation in lakes and streams and excessive nitrates
are a public and animal health hazard, a study was made to compare nitrogen
and phosphorus losses from the soil through drainage water under two levels
of conservation managemen-t. The experimental field was made up of approxi-
mately 12 hectares of a Lima-Kendaia soil association. High and moderate
rates of fertilization were applied. Effluent from the drains was measured
and analyzed for inorganic nitrogen and orthophosphate. During two 3-week
test periods, nitrate calculated as nitrogen delivered from the tile drains
in kilos/ha per week ranged from .225 to 2.75. Ammonium concentrations
seemed to be only slightly related to fertilization, ranging consistently
between .02 to .03 ppm. Weekly outputs of ammonia nitrogen calculated
as nitrogen were less than .00258 kilos/ha. Orthophosphate concentrations
calculated as phosphorus ranged from .004 to .01 ppm with a weekly output
range of .00016 to .00088 kilos/ha. Nitrogen was applied as ammonium nitrate.
Phosphorus was applied at 46% superphosphate.
]
72-73:056-030
PHOSPHORUS LOSSES FROM FOUR AGRICULTURAL WATERSHEDS ON MISSOURI VALLEY LOESS,
Schuman, G.E., Spomer, R.G., and Piest, R.F.
Agricultural Research Service, Lincoln, Nebraska, North Central Region.
Soil Science Society of America Proceedings, Vol 37, No 3, p 424-427,
May-June 1973. 6 tab, 15 ref.
Descriptors: *Phosphates, *Soil erosion, *Water pollution sources, *Path
of pollutants, Adsorption, Sediment yield, Sheet erosion, Suspended load,
Erosion control, Loess, *Iowa.
Phosphorus losses from four field-size experimental watersheds at Treynor,
Iowa, were measured during 1969-71. A contour-planted corn watershed and
a pasture watershed were fertilized at the recommended P rate (39 kg/ha).
A level-terraced and a second contour-planted corn watershed were fertilized
at 2.5 times this rate. At the high level of P fertilization, phosphorus
loss by surface runoff from the contour-planted corn watershed was 0.495
kg/ha in 1969, 1.034 kg/ha in 1970, and 2.130 kg/ha in 1971. Level terraces
greatly reduced P loss by reducing runoff and erosion. Water samples for
all runoff events taken above the overfall of each watershed gully contained
considerably more inorganic P in solution than samples taken at the weir
site, 70 to 230 m downstream. This reduction in solution P was caused by
the adsorption of P by the additional suspended soil material entering the
stream from gully erosion.
72-73:056-031
SOIL STORAGE LIMITATIONS ON EFFLUENT IRRIGATION,
Settergren, C.D.
Missouri University, Columbia.
Water Resources Bulletin, Vol 8, No 6, p 1273-1276, December 1972
2 fig, 9 ref.
(See 72-73:05E-001)
72-73:058-032
ON THE NECESSARY AND SUFFICIENT CONDITIONS FOR A LONG-TERM IRRIGATED
AGRICULTURE,
Moore, C.V.
United States Department of Agriculture, Economic Research Service,
Davis, California.
Water Resources Bulletin, Vol 8, No 4, p 802-812, August 1972. 3 fig, 12 ref.
Descriptors: *Water quality, *Irrigation effects, *Salinity, Salt balance,
Irrigation practices, Water management (applied), Drainage, Water pollution
sources, Soil analysis, Soil chemical properties, Irrigated land. Irrigation
water.
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Salinization and water logging have been the nemesis of irrigated agri-
culture societies. Low quality water substitutes for high quality water for
irrigation at an increasing rate up to the limits of the soil's ability to
transmit the additional water and remove excess salts from the root zone.
Soil transmissibility can be increased by additional investment in
drainage ditches and underground tile. Low valued-high salt tolerant crops
can be substituted for higher valued-salt sensitive crops to maintain pro-
duction in areas served by irrigation water sources of deteriorating quality.
Thus physical factors specify the necessary conditions for survival
of an irrigated agriculture. The conditions for survival must be in terms
of a positive net income in each subplanning period discounted to its present
value.
72-73:058-033
ESTIMATION PROCEDURES FOR RESPONSE FUNCTIONS OF CROPS TO SOIL WATER
CONTENT AND SALINITY,
Yaron, D., Bielorai, H.r Shalhevet, J., and Gavish, Y.
Hebrew University, Jerusalem, Israel.
Water Resources Research, Vol 8, No 2, p 291-300, April 1972. 6 tab, 4 fig,
21 ref.
(See 72-73:02G-041)
72-73:05B-034
MOVEMENT OF NITRATES UNDER IRRIGATED AGRICULTURE,
Edwards, D.M., Fischbach, P.E., and Young, L.L.
Nebraska University, College of Engineering and Architecture, Lincoln.
Transactions of the American Society of Agricultural Engineers, Vol 15,
No 1, p 73-75, January-February, 1972. 6 fig, 14 ref.
Descriptors: *Nitrates, *Nitrogen, *Water pollution sources, Leaching,
Water quality, Nutrient removal, Fertilizers, Nitrogen compounds.
Nitrate nitrogen is highly soluble in water, thereby posing a threat of
water pollution. A coordinated sequence of laboratory and field studies
were conducted. Both mechanical placement and hydraulic injection were
to apply the fertilizer. The following conclusions were drawn; 1. once
nitrates move below the soil surface they do not re-enter the runoff water;
2. nitrates move with the wetting front; 3. with a properly managed
irrigation system little or no movement of nitrates outside the root zone
should occur.
72-73:05B-035
LOSSES OF ATRAZINE IN RUNOFF WATER AND SOIL SEDIMENT,
Hall, J.K., Pawlus, M., and Higgins, E.R.
Pennsylvania State University, University Park Dept. of Soil Chemistry.
Environmental Quality Vol 1, No 2, p 172-176. 1972 Illustration.
Identifiers: *Atrazine loss, Herbicides, Oats, Runoff, Sediment, Soil
sediment, Toxicity, Zeamays, *Pennsylvania, *Corn.
Atrazine losses in runoff water and soil -sediment were determined in 1967
and 1968 after 7 rates (0, 0.6, 1.1, 2.2, 4.5, 6.7, and 9.0 kg/ha) of
atrazine were applied pre-emergent to corn (Zeamays L.) seeded on field
plots of Hagerstown silty clay loam (14% slope). Average losses for all rates
in 1967 in runoff water and soil sediment equaled 2.4% and 0.16% of the
total applied, respectively. In 1967, at the recommended rate (2.2 kg/ha)
for preemergence applications to Pennsylvania soils, composite losses were
2.5% of the applied or approximately 0.05% kg/ha. In 1968, 1 yr after
atrazine application, the average loss over all rates for the combines sub-
strates was 0.01%. Analyses of soil core samples taken from all plots in
1967 revealed that 1 mo. after atrazine application an average of 67.9%
remained in the soil, and 3 mo. later recoveries had decreased to 21.4% of
that applied. The following year atrazine remaining in the soil had decreased
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to 15.9% in April and to 5.4% in September. At the recommended rate of
application, recoveries decreased from 39% of that applied to 9% for the same
time period in 1967. In 1969, typical atrazine toxicity symptoms were found
in oats growing on plots which had received 6.7 and 9.0 kg/ha of atrazine
in 1967. Damage was confined to the uppermost parts of the slope.
72-73:058-036
NITRATE IN SURFACE AND SUBSURFACE FLOW FROM A SMALL AGRICULTURAL WATERSHED,
Jackson, W.A., Asmussen, L.E., Houser, E.W., and White, A.W.
Agricultural Research Service, Watkinsville, Georgia.
Journal of Environmental Quality, Vol 2, No 4, p 480-482, October-December
1972. 1 fig, 2 tab, 8 ref.
Descriptors: *Nitrates, *Path of pollutants, *Fertilizers, *Georgia, Corn
(field), Water quality, Nutrients, Subsurface drainage, *Agricultural water-
sheds.
A small agricultural watershed on Cowarts loamy sand in the Georgia Coastal
Plains was planted in corn each year from 1969 to 1971. Surface and subsur-
face water samples were collected during each natural rainfall runoff event
and No3-N was determined. The initial weighted average No3-N concentration
was 5 ppm in the subsurface runoff for 3 months before the first planting.
The average was 7 ppm in 1969, 10 ppm in 1970, and 9 ppm in 1971. The con-
centration of NO3-N in most of the surface runoff for 3 years was less than
1 ppm; the maximum was 3 ppm. Subsurface flow accounted for 80% of the
total runoff during the study period. Thus, greater amounts of N03-N were
discharged in subsurface flow than in surface flow from this watershed.
72-73:053-037
ISOTOPHIC TRACER TECHNIQUES FOR IDENTIFICATION OF SOURCES OF NITRATE POLLUTION,
Edwards, A.P.
Tennessee Valley Authority, Muscle Shoals, Alabama, Division of Agricultural
Development.
Journal of Environmental Quality, Vol 2, No 3, p 382-387, July-September 1973.
4 tab, 25 ref.
Descriptors: *Tracers, *Path of pollutants, *Nitrates, Nitrogen, Radio-
isotopes, Fertilizers, Pollutant identification.
The use of labeled fertilizers with N-15 contents substantially higher or
lower than the natural abundance figure is the only valid approach to the
measurement of fertilizer contribution to the N03 appearing in tile drains
under field condition. The natural N-15 abundance approach to the measure-
ment of percentage contribution of applied fertilizers to nitrate production
was not successful in well-replicated laboratory incubation experiments.
Time of incubation may be eliminated as a variable by incubating the control
and fertilized sample for the same time and under exactly the same conditions.
72-73:05B-038
SALT PICKUP FROM AGRICULTURAL LANDS IN THE GRAND VALLEY OF COLORADO,
Skogerboe, G.V., and Walker, W.R.
Colorado State University, Fort Collins, Department of Agricultural Engineering.
Journal of Environmental Quality, Vol 2, No 3, p 377-382, July-September 1973.
7 fig, 3 tab, 7 ref.
Descriptors: *Water pollution sources, *Colorado River, *Salinity, *Path of
pollutants, Return flow, Irrigation, *Colorado, Water pollution, Water quality,
Salts.
Identifiers: *Grand Valley (Colo).
Introduction of seepage and deep percolation losses to saline soils and aqui-
fers, and the eventual return of these flows to the river system with their
large salt loads, make the Grand Valley in Colorado one of the more signifi-
cant salinity sources in the Upper Colorado River basin. The principal com-
ponents of both the water and salt flow systems were delineated, and water
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and salt budgets were generated on a monthly basis for the water years 1969-
1971. About 51,039 metric tons of dissolved solids are being added from the
small 1876 ha test area. This salt contribution of about 27.1 metric tons/ha
is proportionate to the valley-wide pickup. From this analysis, it is
concluded that salinity control alternatives must focus on reducing the flow
of water in the groundwater system. Possible measures include conveyance
channel linings and improved on-farm water management practices.
72-73:058-039
NITROGEN TRANSFORMATIONS DURING SUBSURFACE DISPOSAL OF SEPTIC TANK EFFLUENT
IN SANDS: II. GROUND WATER QUALITY,
Walker, W.G., Bouma, J., Keeney, D.R., Olcott, P.G.
Wisconsin University, Madison. Department of Soil Science.
Journal of Environmental Quality, Vol 2, No 4, p 521-525, October-December
1973. 4 fig, 1 tab, 12 ref.
Descriptors: *Path of pollutants, *Soil disposal fields, *Nitrogen, *Bio-
degradation, *Ground water, Soil water, Water pollution sources, Nitrates.
Groundwater observation wells were installed in the immediate vicinity of
four septic tank effluent soil disposal systems. Potentiometric maps were
constructed from measurements of the groundwater level at each site to
establish the direction of movement. Groundwater samples were pumped from
each well to establish patterns of N enrichment in the groundwater around
the seepage beds and to evaluate the performance of these disposal systems
in sands in terms of N removal. Soil disposal systems in sands added
significant quantities of nitrate formed by nitrification of NH4, the dominant
form of N in the effluent, to underlying groundwater. In sands, the only
active mechanism of lowering the NO3-N content is by dilution with uncontam-
inated groundwater. Relatively large areas of 0.2 ha downgradient were
needed before concentrations in the top layer of the groundwater were lower
than 10 mg/liter. The average N-input per person was 8 kg per year. Essen-
tially complete nitrification in the soil results in addition of approxi-
mately 33 kg N03-N to the groundwater per year for an average family of four.
72-73:058-040
NITROGEN TRANSFORMATIONS DURING SUBSURFACE DISPOSAL OF SEPTIC TANK EFFLUENTS
IN SANDS: 1. SOIL TRANSFORMATIONS,
Walker, W.G., Bouma, J., Keeney, D.R., and Magdoff, F.R.
Wisconsin University, Madison. Department of Soil Science.
Journal of Environmental Quality, Vol 2, No 4, p 475-480, October-December
1973. 7 fig, 4 tab, 21 ref.
Descriptors: *Soil disposal fields, *Nitrogen, *Path of pollutants, *Bio-
degradation, Nitrification, Septic tanks, Hydraulic conductivity, Unsaturated
flow.
Identifiers: Soil crusting.
Soil physical and chemical studies of five subsurface septic tank seepage
beds were conducted to determine the biochemical transformations of N and
thereby its potential for groundwater pollution. Effluent was ponded in all
the seepage beds examined due to the presence of an impeding layer, a 'crust' ,
at the boundary between the gravel bed and adjacent soil. The crust reduced
infiltration rates approximately from 500 to 8 cm/day. Soil atmospheric
composition 5 cm below the crust averaged 19.6% 02 and 0.66% C02. Nitrogen
in the septic tank effluent occurred as NH4-N (80%) and organic N (20%)
with virtually no N03-N. Organic-N was largely concentrated in the crust
zone. Nitrification of NH4-N to N03-N was essentially complete and commenced
in the unsaturated subcrust soil within about 2 cm of the crust. Nitrification
did not occur and NH4-N was absorbed by the soil below a seepage bed that
was submerged in the groundwater.
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72-73:05B-041
RECYCLING AND RECOVERY OF NITROGEN, PHOSPHORUS, AND POTASSIUM BY COASTAL
BERMUDAGRASS: II. UNDER GRAZING CONDITIONS WITH TWO STOCKING RATES,
Rouquette, P.M., Jr., Matocha, J.E., Duble, R.L.
Texas A&M University, Agricultural Research and Extension Center, Overton.
Journal of Environmental Quality, Vol 2, No 1, p 129-132, January-March, 1973.
3 fig, 1 tab, 27 ref.
Descriptors: *Water pollution sources, *Fertilizers, Nitrogen, Phosphorus,
Potassium, Nutrient removal, Leaching, Coastal bermudagrass, Pastures,
Forages, Groundwater.
The effect of two stocking rates on the recycling of N, P,- and K was studied
for 2 years on a Coastal bermudagrass. Samples for chemical analysis were
taken at 14-day intervals. Available forage, forage yield, and forage con-
sumption were estimated from samples taken at 2- to 4-week intervals. Soil
samples were taken prior to, during, and at termination of the grazing
trial. Plant nutrient recycling on the high stocked pastures was approx-
imately twice as great during the dry, 1969 season and about 10% higher
during the 1970 season compared to that on the low stocked pastures. Recover-
ies of applied plant nutrients averaged over stocking rates were 84, 50, and
155% for N, P, and K respectively, during 1969, and 180, 73, and 172%
for N, P, and K, respectively, during 1970. There was a substantial soil
accumulation of plant nutrients under both stocking rates with a considerable
advantage in favor of the high stocked pastures.
72-73:058-042
RECYCLING AND RECOVERY OF NITROGEN, PHOSPHORUS, AND POTASSIUM BY COASTAL
BERMUDAGRASS: 1. EFFECT OF SOURCES AND RATES OF NITROGEN UNDER A CLIPPING
SYSTEM,
Matocha, J.E., Rouguette, P.M., Jr., and Duble, R.L.
Texas A&M University, Agricultural Research and Extension Center, Overton.
Journal of Environmental Quality, Vol 2, No 1, p 125-129, January-March,
1973. 5 fig, 2 tab, 17 ref.
Descriptors: *Water pollution sources, *Fertilizers, *Nitrogen, Nitrates,
Leaching, Nutrient removal, Coastal bermudagrass, Forages, Phosphorus,
Potassium, Groundwater.
A field experiment was conducted to determine recovery efficiencies for
applied N, P, and K under a system of total removal of forage over a 3-year
period. Ammonium nitrate (NH2)2CO, and (NH4)2S04 were each applied in
split application of 0, 280, 560, and 840 kg N/ha each season. Soil levels
of total N, chemically extractable P, and K were monitored each season.
Characteristic decreases in recoveries occurred with increasing N rates.
Average P recovery percentages for NH4N03 were 34, 46, and 52% for rates
of 280, 560, and 840 kg N/ha, respectively. Plant recovery of applied K was
greatest for (NH4)2S04 and lowest for (NH2)2CO. Average values for (NH4)2S04
were 108, 165, and 222% for the low, medium, and high rates of N, respectively.
Ammonium sulfate gave greater accumulation of soil N with time than NH4N03
or (NH2)2CO while chemically extractable soil P and K were highest for NH4N03.
72-73:05B-043
CHEMICAL DISTRIBUTION OF RESIDUAL FERTILIZER NITROGEN IN SOIL AS REVEALED
BY NITROGEN-15 STUDIES,
Allen, A.L., Stevenson, F.J., and Kurtz, L.T.
Langston University, Department of Agriculture, Langston, Oklahoma.
Journal of Environmental Quality, Vol 2, No 1, p 120-124, January-March,
1973. 5 fig, 18 ref.
Descriptors: *Water pollution sources, *Nitrogen, *Fertilizers, Leaching,
Nutrient removal. Nitrates, Radioisotopes, Salinity, Groundwater.
Chemical distribution patterns were obtained for the residual N in field plots
previously amended witn Nl5-labeled urea and oxamide. From 25 to 40% of
the fertilizer N was present in the soil (0 to 25 cm) after the first growing
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season, about half of which still remained after 5 years. Essentially all
of the fertilizer-derived N occurred in organic combination; only a small
fraction was accounted for in inorganic forms, chiefly as fixed NH4. In
comparison to the native humus N, higher percentages of the fertilizer N
left after the first growing season occurred as amino acids and amino sugars;
lower percentages occurred in acid-insoluble N. Considerable humification
occurred during the subsequent 4 years with relocation of amino acids N to
more resistant humus forms. The findings suggest that fertilizer N, once
incorporated into soil organic matter, becomes increasingly stable with time
and is not readily mineralized or subject to leaching.
72-73:05B-044
MOVEMENT OF NITRATE NITROGEN IN SOME GRASSLAND SOILS OF SOUTHERN ALBERTA,
Sommerfeldt, T.G., and Smith, A.D.
Canada Department of Agricultural Research Stations, Lethbridge, Alberta
Journal of Environmental Quality, Vol 2, No 1, p 112-115, January-March,
1973. 5 fig, 3 tab, 14 ref.
Descriptors: *Water pollution sources, *Nitrogen, *Grasslands, Grasses,
Leaching, Nutrient removal, Leaching, Canada, Salinity, Groundwater, Fer-
tilizers.
The downward movement of NO3-N in dryland soils under native grass 6 to 8
years after N was applied at rates up to 976 kg/ha reached a depth of 180
cm. Phosphorus fertilizer did not affect NO3-N movement. Under seeded
grasses, there was no evidence of N03-N accumulation 2 years after a single
application of N at rates up to 944 kg/ha. After repeated annual applications
of N that totaled up to 3776 kg/ha over a 4-year period, N03-N accumulations
were found to depths of 90 to 120 cm. The depth of NO3-N movement under
bromegrass was similar to that under crested wheatgrass, but more NO3-N
accumulated in the soil under the bromegrass. In irrigated soil underlaid
by drains, N03-N leaching was greater in a loam soil over till growing a
mixture of bromegrass and alfalfa than in a loam soil over sandy loam-
loamy sand growing an irrigated pasture-grass mixture. These studies
indicated that, with good management, fertilizer N on grassland soils is not
an important contributor to pollution in semiarid southern Alberta.
72-73:05B-046
CHEMICAL AND BIOCHEMICAL CONSIDERATIONS FOR MAXIMIZING THE EFFICIENCY OF
FERTILIZER NITROGEN,
Parr, J.F.
United States Department of Agriculture, Agricultural Research Service,
Baton Rouge, Louisiana.
Journal of Environmental Quality, Vol 2, No 1, p 75-84, January-March, 1973.
6 fig, 2 tab, 56 ref.
Descriptors: *Water pollution sources, *Nitrogen, *Fertilizers, Nutrient
removal, Leaching, Salinity, Nitrates, Nitrification, Groundwater.
Fertilizer nitrogen is subject to loss from the soil-root zone, and immob-
ilization by the soil and rhizosphere microfloras, which can result in low
recovery and use efficiency of the applied nitrogen. With increasing rates
of application, fertilizer nitrogen efficiency decreases progressively, while
leaving an increasing amount of unused nitrogen as a potential pollution
hazard. Since the point of greatest economic return from this nutrient is
usually somewhere below the point of maximum yield, it should be possible
to adjust fertilizer nitrogen rates for maximum return and minimum loss to
the environment. This can be achieved through improved soil and crop manage-
ment practices, including proper timing of application of conventional
nitrogen fertilizers and use of deep-rooted crops for recovery of leached
nitrate. Efficiency of fertilizer nitrogen might also be increased with con-
.trolled release fertilizers, including the use of coated granules, and com-
pounds of limited water solubility blended with conventional nitrogen ferti-
lizers.
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72-73:053-047
AGRICULTURAL CHEMICALS IN RELATION TO ENVIRONMENTAL QUALITY: CHEMICAL FER-
TILIZERS, PRESENT AND FUTURE,
Nelson, L.B.
Tennessee Valley Authority, Office of Agricultural and Chemical Development,
Muscle Shoals, Alabama.
Journal of Environmental Quality, Vol 1, No 1, p 2-6, January-March, 1972.
15 ref.
Descriptors: *Water pollution sources, *Fertilizers, *Leaching, Nutrient
removal, Runoff, Erosion, Agricultural chemicals, Nitrogen, Phosphorus,
Potassium.
In the USA, fertilizers have accounted for over 50% of the increase in crop
production since 1940, and farmers have substituted fertilizers for land and
other inputs. However, considerable controversy has developed in recent
years over the role of fertilizers in pollution of natural waters. Increased
nitrate and phosphate levels in waters are cited by ecologists as proof of
contamination by fertilizers, but this is contested by many agriculturists.
Examination by competent reviewers of the limited data available so far
indicates that losses of fertilizer nutrients into surface and groundwaters
may be minimal under most situations. There are a number of ways to mini-
mize losses without sacrificing the important benefits gained from ferti-
lizers. These include carefully tailoring rates and times of nitrogen
application to better fit the needs of the growing crop, greater care in
irrigation, use of slow-release nitrogen fertilizers, and wider application
of selected soil conservation practices to control surface losses of both
nitrates and phosphates.
72-73:05B-048
PATE OF NITRATE FROM MANURE AND INORGANIC NITROGEN IN A CLAY SOIL CROPPED
TO CONTINUOUS CORN,
Kimble, J.M., Bartlett, R.J., Mclntosh, J.L., and Varney, K.E.
Vermont University, Department of Plant and Soil Science, Burlington.
Journal of Environmental Quality, Vol 1, No 4, p 413-415, October-December,
1972. 5 fig, 1 tab, 6 ref.
Descriptors: *Water pollution sources, *Nitrogen, *Nutrient removal, Deni-
trification, Leaching, Nitrogen cycle, Fertilizers, Nitrates.
Effects of dairy manure and N fertilizer were studied on plots that had
received in a factorial arrangement two levels of manure (0 and 66 metric
tons/ha) and two levels of N (0 and 224 kg/ha) applied every spring for 6
years. Laboratory incubation studies using soil profile samples showed
potential denitrification to be greater in soil from the manure treated plots
than in plots receiving either inorganic N or no N. The amount decreased
with depth to 96 cm, below which energy for anaerobic microbial activity
appeared to be limiting. Laboratory analyses of profile samples indicated
decreasing nitrate-N/chloride ratios at all depths from fall to spring,
suggesting that denitrification rather than leaching was responsible for a
significant portion of the nitrate loss during this period. Abrupt decreases
in the nitrate-N/chloride ratios from the surface to the 45- to 71-cm
depth indicated that denitrification had taken place and that a nitrate
bulge at 96- to 122-cm probably was caused by denitrification above that
depth.
72-73:056-049
INCREASED DENITRIFICATION IN SOILS BY ADDITIONS OF SULFUR AS AN ENERGY SOURCE,
Mann, L.D., Focht, D.D., Joseph, H.A. , and Stolzy, L.H.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Journal of Environmental Quality, Vol 1, No 3, p 329-332, July-September, 1972.
1 fig, 6 tab, 18 ref.
271
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Descriptors: *Denitrification, *Soil amendments, *Leaching, Nutrient
removal, Water pollution sources, Reduction, Oxidation.
Denitrification rates were studied in four large soil columns using Hanford
sand loam and Moreno silty clay loam soils. One column of each soil was
amended with sulfur to serve as an energy source for the bacterium Thio-
bacillus denitrificans. Limestone was also added as a pH buffer. The
other column of each soil was left untreated to serve as a control. A solution
of Ca(NO3)2 containing 425 ppm NO3-N was perfused continuously through the
columns. The columns were monitored periodically at depths of 10, 30, 50,
70, and 90 cm for nitrate, nitrite, redox potential and microbial numbers.
Highly anaerobic conditions developed in all columns. All of the nitrate
was reduced in each column, and nitrates penetrated to lower depths in
the untreated columns. Nitrite concentrations were found to be negligible
Sulfur additions to field soils which are low in microbial energy sources
could be an effective method of reducing the nitrate level in waters per-
colating through the profile.
72-73:058-050
NITRATE IN UNSATURATED ZONE OF AN ALLUVIAL SOIL IN RELATION TO FERTILIZER
NITROGEN RATE AND IRRIGATION LEVEL,
Adriano, D.C., Pratt, P.F,, and Takatori, F.H.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Journal of Environmental Quality, Vol 1, No 4, p 418-422, October-December,
1972. 5 fig, 3 tab, 10 ref.
Descriptors: *Water pollution sources, *Fertilizers, *Nitrates, Nutrient
removal, Leaching, Asparagus, Unsaturated flow. Nitrogen cycle, Denitri-
fication.
Soil samples to the 15-m depth beneath asparagus and celery were taken to
determine the N03 concentration in the solution of the unsaturated zone and
to estimate the soil N balance. Transit time for water to move to the 15-m
depth was calculated from drainage volumes and volumetric water contents.
Nitrogen balance was calculated from data for N input, N removal in har-
vested crops, and water records for the calculated transit time. The NO3
concentration in the unsaturated zone increased with increase in N rate but
was inversely related to the leaching volume. Denitrification was assumed
to be the cause of the low efficiency of recycling N by these crops. The
data suggest that high rates of N combined with high levels of water use
are conducive to denitrification in relatively permeable soils.
72-73:058-051
A SIMPLE DIGESTION PROCEDURE FOR ESTIMATION OF TOTAL NITROGEN IN SOILS AND
SEDIMENTS,
Nelson, D.W., and Sommers, L.E.
Purdue University, Department of Agronomy, Lafayette, Indiana.
Journal of Environmental Quality, Vol 1, No 4, p 423-425, October-December,
1972. 5 tab, 12 ref.
Descriptors: *Dlgestion, *Nitrogen, Nutrients, Fertility, Soils, Soil
chemistry. Soil investigations.
Identifiers: Kjedahl, Steam distillation, Hydrofluoric acid.
A simple and convenient digestion procedure *for total N analysis of soils
and sediments is described. The digestion is carried out in pyrex Folin-
Wu tubes heated in an aluminum block placed on a hot plate. Samples up to
1 g in size may be used and a digestion time of three hours after clearing
is adequate. The proposed and conventional semimicro-Kjeldahl methods gave
essentially the same values for total N in a wide variety of soils and sedi-
ments. The precision of the proposed method was almost as good as those
reported for other semimicro-Kjeldahl methods. The tube digestion method
allows simultaneous digestion of 60 samples in a relatively inexpensive
and maintenance-free aluminum heating block, which occupies a minimum of
laboratory space and appears applicable for routine determination of total n
in soils having diverse properties.
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72-73:058-052
CONCENTRATIONS OF NITROGEN, PHOSPHORUS, POTASSIUM, AND TOTAL SOLUBLE SALTS
IN SOIL SOLUTION SAMPLES FROM FERTILIZED AND UNFERTILIZED HISTOSOLS,
Hortenstine, C.C. and Forbes, R.B.
Florida University, Soil Science Department, Gainesville.
Journal of Environmental Quality, Vol 1, No 4, p 446-449, October-December,
1972. 5 fig, 9 ref.
Descriptors: *Water pollution sources, *Runoff, Surface runoff, Subsur-
face runoff. Agricultural runoff. Nitrogen, Phosphorus, Potassium, Nutrient
removal, Peat.
Lake Apopka ranked at one time among the most productive bass and panfish
bodies of water in the United States. During recent years this lake became
eutrophic and fishing declined drastically. Farming operations on the rich
organic soil along the northern shore of the lake were implicated as one
cause of this eutrophication. To measure agriculture's contributions to the
nutrient concentration in the lake, soil solution samples were extracted
from uncleared, swampy Everglades mucky peat; newly cleared, drained Ever-
glades mucky peat; and Everglades mucky peat that had been under cultivation
for approximately 15 years. Nitrate-N, orthophosphate P, and K concen-
trations were relatively low in soil solution samples from the swampy area.
Concentrations of each nutrient in soil solution extracted at the 60-cm
depth in the newly cleared area increased by as much as 8 to 12 times as
compared to the 60-cm depth in the swampy area. Further increases were
noted in the cultivated area. Indications were that the peat itself was
a heavy contributor of nutrients to the drainage water.
72-73:058-053
NITROGEN-15 ENRICHMENT OF SOILS AND SOIL-DERIVED NITRATE,
Bremner, J.M., and Tabatabai, M.A.
Iowa State University, Department of Agronomy, Ames.
Journal of Environmental Quality, Vol 2, No 3, p 363-365, July-September, 1973.
3 tab, 12 ref.
Descriptors: *Nitrates, *Nitrogen, Leaching, Nutrient removal. Water pollution
sources, Radioisotopes.
Identifiers: Nitrogen-15, Soil-derived nitrate
Nitrogen-isotope analysis of soils and soil-derived nitrate showed that there
is considerable variation in the N15 enrichment of the nitrate nitrogen
produced on aerobic incubation of different soils and that the Nl5-enrich-
ment of this nitrate nitrogen depends upon the time of incubation and can
differ markedly from that of the total soil N. The data reported illustrate
the impracticability of a recently proposed method of assessing the contri-
bution of fertilizers to nitrate in surface waters that requires measurement
of the natural N15 enrichment of soil- and fertilizer-derived nitrate.
72-73:058-054
NITROGEN TRACERS IN NITROGEN CYCLE STUDIES - PAST USE AND FUTURE NEEDS,
Hauck, R.D.
Tennessee Valley Authority, Division of Agricultural Development, Muscle
Shoals, Alabama.
Journal of Environmental Quality, Vol 2, No 3, p 317-327, July-September,
1973. 2 tab, 56 ref.
Descriptors: *Nitrogen cycle, *Nitrogen compounds. Nitrogen fixation, Radio-
isotopes, Nutrient removal, Leaching, Water pollution sources, Nitrates.
To achieve N balance in productive ecosystems, better quantitative estimates
of N transformation rates are needed. Nitrogen tracers are indispensable
for making many of these estimates. Either N15-depleted or Nl5-enriched
materials can be used. The use of Nl5-depleter materials is limited to studies
where dilution from other N is less than 2,000-fold, but these materials
are potentially available in ton amounts. Use of variations in natural
N15 abundance may be useful in observing qualitative relationships among N
273
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cycle processes over large areas or extremely long time periods. Such use
is questionable for obtaining quantitative information for short-term N
transformation processes. Obvious information gaps are quantitative data
on atmospheric N2 fixation and denitrification in cropped field soils and N
transformation data for many other ecosystems. A program for computer data
retrieval and correlation is outlined.
72-73:05B-055
DISTRIBUTION AND CHEMISTRY OF PHOSPHORUS IN AN ALBAQUALF SOIL AFTER 82 YEARS
OF PHOSPHATE FERTILIZATION,
Kao, C. W., and Blanchar, R. W.
Missouri Agricultural Experiment Station.
Journal of Environmental Quality, Vol. 2, No. 2, p 237-240, April-June, 1973.
2 fig, 3 tab, 25 ref.
(See 72-73:020-055)
72-73:058-056
PLANT NUTRIENT CONCENTRATIONS IN RUNOFF FROM FERTILIZED CULTIVATED EROSION
PLOTS AND PRAIRIE IN EASTERN SOUTH DAKOTA,
White, E. M., and Williamson, E. J.
South Dakota State University, Plant Science Department, Brookings.
Journal of Environmental Quality, Vol. 2, No. 4, p 453-455, October-December,
1973. 3 tab, 6 ref.
Descriptors: *Water pollution sources, *Water pollution control, *Nutrient
removal, Agricultural runoff, Fertilizers, Nitrogen, Phosphorus, Surface runoff,
Rainfall-runoff relationships.
Runoff waters from fertilized erosion plots and from native prairie in South
Dakota were compared to determine the effect agriculture has had on water
quality. Calcium, Mg, K, Na, total P, PO4-P, N03-N, and NH4-N contents were
found to be similar in runoff from the erosion plots and from the pririe. The
elemental contents in runoff from erosion plots planted to oats and alfalfa
or fallowed were not distinctly different and varied from year to year.
Variations in the ions in water collected from different basins in the prairie
may be caused by differences in the prairie vegetation and mulch in the drainage
basins, in the time the runoff has to dissolve ions because of different
overland flow distances, and in the dilution of the runoff by precipitation
that falls directly into the basin. Losses of plant nutrients in soil eroded
from cultivated land may be similar to average losses that would occur naturally
if the area were in pristine prairie that was periodically subjected to fire.
72-73*058-057
LONG-TERM EFFECTS OF MANURE, FERTILIZER, AND PLOW DEPTH ON CHEMICAL PROPERTIES
OF SOILS AND NUTRIENT MOVEMENT IN A MONOCULTURE CORN SYSTEM,
Vitosh, M. L., Davis, J. F., and Knezek, B. D.
Michigan Agricultural Experiment Station, Crop and Soil Science Department,
East Lansing.
Journal of Environmental Quality, Vol. 2, No. 2, p 296-299, April-June, 1973.
5 tab, 20 ref.
Descriptors: *Animal wastes (wildlife), *Farm wastes, ^Fertilizers, Solid
wastes. Organic matter. Nutrient removal.
An evaluation of soil chemical properties, organic matter and nutrient accumula-
274
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tions, and nutrient movement and recovery after 6 and 9 years of annual fertili-
zer and manure applications to continuous corn was conducted on two soil types.
Plow depths of 18 versus 30 cm had little or no effect on soil test values or
nutrient accumulation patterns in the surface of a Conover-Hodunk loam soil.
The pH value of both soils decreased slightly more than 0.1 pH unit per year
with the annual application of 168 kg of N/ha as ammonium sulfate. The most
favorable rate of manure for the Metea sandy loam soil was found to be 22.4
metric tons/ha (10 tons/acre). Larger applications caused a significant build-
up of exchangeable K in the surface and subsurface horizons and resulted in
inefficient use of all nutrients. The K buildup was less critical on the loam
soil or where silage rather than grain was removed.
72-73:05B-058
NITROGEN LOSSES IN SURFACE RUNOFF FROM AGRICULTURAL WATERSHEDS ON MISSOURI
VALLEY LOESS,
Schuman, G. E., Burwell, R. E., Piest, R. P., and Sportier, R. G.
United States Department of Agriculture, Agricultural Research Service, Lincoln,
Nebraska.
Journal of Environmental Quality, Vol. 2, No. 2, p 299-302, April-June, 1973.
5 tab, 15 ref.
Descriptors: *Nitrogen, *Leaching, *Nutrient removal, Solubility, Pollutants,
Soil chemistry, Dispersion, Fertilizers, Sediments, Erosion.
Nitrogen losses from surface runoff from four field-size (30 to 60.8 ha) water-
sheds in southwestern Iowa, near Treynor, were measured during 1969, 1970, and
1971. A contour-planted corn watershed and a pasture watershed were fertilized
at the recommended N rate (168 kg/ha). A level-terraced and a contour-planted
corn watershed were fertilized at 2.5 times this rate. The conservation prac-
tice of level-terraced corn or pasture was very effective in reducing water,
sediment, and N yields when compared with the contour-planted corn watersheds.
Annual water-soluble N losses were low from all watersheds. The three-year
average annual solution N loss from the contour-planted corn watershed, ferti-
lized at 2.5 times the recommended rate, was 3.05 kg/ha; the comparable water-
shed, fertilized at the recommended rate, lost only 1.89 kg/ha.
72-73:05B-059
EXPERIMENTAL AND PREDICTED MOVEMENT OF THREE HERBICIDES IN A WATER-SATURATED
SOIL,
Davidson, J. M., and McDougal, J. R.
Oklahoma State University, Agronomy Department, Stillwater.
Journal of Environmental Quality, Vol. 2, No. 4, p 428-433, October-December,
1973. 7 fig, 1 tab, 19 ref.
Descriptors: *Water pollution sources, *Herbicides, Adsorption, Dispersion,
Pore water.
Identifiers: Equilibrium adsorption, Herbicide movement.
The equilibrium adsorption characteristics of 1, l-dimethyl-3-urea, 4-amino-3,5,
6-trichloropicolinic acid, and 2, 4-bis-6-s-triazine on Ca-saturated Norge
loam soil were measured and were found to fit the Freundlich equation. A
solution of each herbicide was displaced through a water-saturated column of
Norge loam soil at various average pore-water velocities and effluent samples
evaluated to determine the importance of adsorption kinetics to the mobility
of the herbicide. The displacement of each herbicide through the soil was
275
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significantly influenced by the average pore-water velocity. The use of a
kinetic adsorption model in a convective transport equation did not adequately
predict the shape of the effluent concentration distribution at the high
pore-water velocities, but did give the left-hand shift exhibited by the data.
Equilibrium adsorption and desorption isotherms were measured for picloram on
Ca-saturated Norge loam soil.
72-73:05B-060
BIONOMICS AND INTEGRATED CONTROL OF PLANT PARASITIC NEMATODES,
Good, J. M.
United States Department of Agriculture, Agricultural Research Service, Belts-
ville, Maryland.
Journal of Environmental Quality, Vol. 1, No. 4, p 382-386, October-December,
1972. 1 tab, 41 ref.
Descriptors: *Nematodes, *Nematocides, Cultivation, Entomology, Microbiology,
Soil microorganisms, Soil sterilants, Water pollution sources.
Establishment of an agroecosystem promotes the rapid increase of endemic
pathogenic species and allows introduction of nonendemic species that quickly
establish dominance. Nematodes now cause about 10% loss of yields of crops in
the United States. About 20 highly effective nematicides are available to
control nematodes and associated plant diseases in a number of crops. Nematode
populations can be regulated by a number of soil management practices, including
clean transplant, seed production, and crop rotations. Biological control can
be achieved by addition of various types of organic matter to soil, some of
which are not presently utilized, especially biodegradable solid waste. Over
152 nematode-resistant crop varieties representing 17 major crops are available
with resistance from one to three species of the 10 most destructive nematode
types. Physical methods of control, including quarantine, sanitation, and
crop destruction, are not vigorously applied.
72-73:05B-061
ISOTOPE PRACTIONATION OP N15 and N14 IN MICROBIOLOGICAL NITROGEN TRANSFORMA-
TIONS: A THEORETICAL MODEL,
Focht, D. D.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Journal of Environmental Quality, Vol. 2, No. 2, p 247-252, April-June, 1973.
2 fig, 1 tab, 29 ref.
Descriptors: *Nitrogen, *Fertilizers, *Isotope fractionation. Isotope studies,
Stable isotopes, Analytical techniques.
The kinetics for first-order multisequence reactions are derived for microbial
fractionation of N14 and N15 isotopes. The isotope effect accounts for unre-
acted substrate becoming progressively enriched in the heavier isotope due to
preferential utilization of the lighter isotope by microorganisms. Consequent-
ly, during denitrification nitrate becomes enriched in N15 as its concentration
diminishes. This inverse proportional relationship is expressed as a hyper-
bolic function. Similar curves are derived for nitrate originating from
ammonification and/or nitrification. Regression coefficients for a straight
line approximation are better than -0.98, but not as good as the actual coeffic-
ients for the derived hyperbolic equations. A negative regression "line" for
nitrate occurs for all denitrification reactions during isotope discrimination.
276
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72-73:05B-062
AGRICULTURAL CHEMICALS IN SURFACE RUNOFF, GROUND WATER, AND SOIL: I. ENDRIN,
Willis, G. H., and Hamilton, R. A.
United States Department of Agriculture, Agricultural Research Service, Baton
Rouge, Louisiana.
Journal of Environmental Quality, Vol. 2, No. 4, p 463-466, October-December,
1973. 4 tab, 11 ref.
Descriptors: *Water pollution sources, *Agricultural chemicals, *Pesticides,
Runoff, Subsurface runoff, Surface runoff, Groundwater.
Endrin was surface applied at a rate of 0.337 kg/ha to sugarcane plots instru-
mented to sample surface runoff and groundwater. Runoff, groundwater, and
soil samples were collected over a two-year period and analyzed for endrin.
Only small amounts of endrin were lost annually in runoff (less than 0.2%
of that applied), and little endrin accumulated in soil. Trace amounts of
endrin appeared to move through soil in the plots but not through soil columns.
A delay of 72 hours between application and rainfall decreased the amount of
endrin in runoff, groundwater, and soil.
72-73:05B-063
MINIMIZING NITRATE SEEPAGE FROM THE HULA VALLEY INTO LAKE KINNERET (SEA OF
GALILEE): I. ENHANCEMENT OF NITRATE REDUCTION BY SPRINKLING AND FLOODING,
Raveh, A., and Avnimelech, Y.
Israel Institute of Technology, Soil and Fertilizer Laboratory, Haifa.
Journal of Environmental Quality, Vol. 2, No. 4, p 455-458, October-December,
1973. 3 fig, 4 tab, 11 ref.
Descriptors: *Water pollution sources, *Nutrient removal, *Nitrates, Denitri-
fication. Nutrient removal. Fertilizers, Irrigation practices, Sprinkler irri-
gation, Surface irrigation. Flood irrigation.
Decomposition of organic matter in the drained soils of the Hula Valley leads
to the accumulation of nitrates. These are leached during the rainy season
to the Jordan River and endanger Lake Kinneret. Field studies have shown
that nitrates can be reduced through the use of the irrigation systems existing
in the area. A treatment of either sprinkling or flooding by raising the water
table reduced the nitrate concentration to about half of its original amount.
Both treatments induced anaerobic conditions in the soil and reduced the
nitrate contents, probably by denitrification. The efficiency of the reduction
depends on the existence of labile organic substrates in the soil.
72-73:058-064
A STUDY OF FACTORS INFLUENCING THE NITROGEN AND PHOSPHORUS CONTENTS OF NEBRASKA
WATERS,
Muir, J., Seim, E. C., and Olson, R. A.
Nebraska University, Agricultural Experiment Station, Lincoln.
Journal of Environmental Quality, Vol. 2, No. 4, p 466-470, October-December,
1973. 1 fig, 5 tab, 14 ref.
Descriptors: *Nitrogen, *Phosphorus, *Fertilizers, Phosphates, Nutrient remov-
al. Pollutants, Water pollution, Water pollution sources, Irrigation, Streams,
Groundwater.
Correlation studies reveal little relation between N and P concentrations of the
277
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water and agricultural use of fertilizers. Nutrient levels in the water are
governed more by human and livestock densities aid intensity of irrigation
development than by agronomic production factors. Only at sites of intensive
irrigation development on very sandy soils and with irrigation of valley posi-
tions of shallow water table has fertilizer N contributed substantially to
reduction in groundwater quality. Nutrient concentrations in streams fluctuate
widely with (i) varied time and rate of organic waste intrusions and subsequent
biological assimilation and (ii) major runoff events. Reservoirs on streams
also have a major modifying action in reducing sediment and fertility load.
The observed higher N content of streams during periods of peak flow can be
attributed partially to the high N content of precipitation and its direct
runoff into streams during periods of high rainfall intensity.
72-73:05B-065
THE PERSISTENCE AND MOVEMENT OF PICLORAM AND 2, 4, 5-T IN SOILS,
Lutz, J. F., Byers, G. E., and Sheets, T. J.
North Carolina State University, Agricultural Experiment Station, Raleigh.
Journal of Environmental Quality, Vol. 2, No. 4, p 485-488, October-December,
1973. 1 fig, 5 tab, 24 ref.
Descriptors: *Herbicide, *2,4,5-T, *Leaching, Pesticide kinetics. Pollutants,
Water pollution, Defoliants, Weed control, Soil properties, Soil chemistry.
Soil physics.
The movement and persistence, of picloram (4-amino-3,5,6-trichloropicolinic
acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) were studied on a western
North Carolina watershed on which extensive agronomic, hydrologic, and climatic
data had been accumulated over a period of 18 years. Picloram was more persis-
tent than 2,4,5-T; approximately 60?6 of the picloram and 90% of the 2,4,5-T
disappeared in 15 days. There was some penetration into the soil, but a very
high percentage of the total amount present at the different sampling periods
was in the 0- to 7.5-cm layer. Doubling the application rate (4.48 vs. 2.24
kg/ha) resulted in a two-fold increase in the amount of herbicide recovered at
each sampling period. Very little downslope movement of either herbicide
occurred even though the average slope on the plots was approximately 27%.
Practically no herbicide was found more than 0.3 m, and none beyond 1.2 m,
downslope. More picloram than 2,3,5-T moved.
72-73:05B-066
NITROGEN AND PHOSPHORUS COMPOSITION OF SURFACE RUNOFF AS AFFECTED BY TILLAGE
METHOD,
Romkens, M. J. M., Nelson, D. W., and Mannering, J. V.
United States Department of Agriculture, Lafayette, Indiana.
Journal of Environmental Quality, Vol. 2, No. 2, p 292-295, April-June, 1973.
2 fig, 4 tab, 12 ref.
(See 72-73:02E-011)
72-73:05B-067
AGRICULTURAL RUNOFF-CHARACTERISTICS AND CONTROL,
Loehr, R. C.
Cornell University, Ithaca, New York, Department of Civil and Agricultural
Engineering.
Journal of the Sanitary Engineering Division, American Society of Civil Engi-
278
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neers. Vol. 98, No. SA6, Paper 9406, p 909-925, December, 1972. 1 tab, 30 ref.
Descriptors: *Water pollution sources, *Farm wastes, *Water pollution control.
Confinement pens. Feed lots, Fertilizers, Runoff.
Agricultural runoff consists of nonpoint sources that range from almost natural
runoff to that from concentrated agricultural operations such as animal feed-
lots and fertilized fields. Control of pollution is possible by waste manage-
ment and land conservation techniques. Increases in agricultural efficiency
have been associated with a variety of potential and real environmental prob-
lems. Some pollution problems of agricultural runoff are quantified and dis-
cussed. The discussion includes erosion, animal feedlots, rural runoff, pollu-
tion characteristics, and effects of fertilizers. Management methods to control
the quantity and pollutional quality of the runoff are noted. Agriculture
should institute a systematic, coordinated approach for specific production
operations to reduce excesses that could cause environmental degradation.
72-73:05B-068
NONLINEAR PARAMETER ESTIMATION IN WATER QUALITY MODELING,
Shastry, J. S., Fan.- L. T., and Erickson, L. E.
Kansas State University, Manhattan, Department of Chemical Engineering.
Journal of the Environmental Engineering Division, American Society of Civil
Engineers, Vol. 99, No. EE3, Proceedings paper 9798, p 315-331, June, 1973.
7 fig, 7 tab, 30 ref.
Descriptors: *Water quality, *Model studies, *Statistical methods, *Biochemical
oxygen demand, *Environmental engineering, Parametric hydrology, Least squares
method. Estimating, Computer programs, Dissolved oxygen, Systems analysis,
*California.
Identifiers: *Sacramento River (California), Parametric equations, Nonlinear
parameters.
Water quality in streams, lakes and estuaries is generally measured in terms
of the dissolved oxygen concentration and biochemical oxygen demand. Mathemat-
ical models for describing the behavior of DO and BOD are briefly reviewed.
Three specific models are examined and parameters in these models are estimated
using a nonlinear parameter estimation technique. Water quality data for
parameter estimation were obtained from the Sacramento River survey. Statisti-
cal analysis is performed on the results obtained by calculating the residuals
and F ratios for equality of variances. Results show that a model with a
nonlinear decay term for BOD fits the data better than does the frequently
used model with a linear decay term.
72-73:056-069
EFFECTS OF PHOSPHORUS APPLICATION RATE, SOIL PROPERTIES, AND LEACHING MODE ON
P-32 MOVEMENT IN SOIL COLUMNS,
Logan, T. J., and McLean, E. O.
Ohio State University, Columbus.
Soil Science Society of America Proceedings, Vol. 37, No. 3, p 371-374, May-
June 1973. 2 fig, 2 tab, 13 ref.
Descriptors: *Leaching,*Phosphates, *Water pollution sources, *Fertilizers,
Path of pollutants. Adsorption, Solubility, Nutrients, Nutrient removal.
Identifiers: *Phosphorus fixation.
279
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Movement of monocalcium phosphate labeled with P-32 was investigated in column
experiments with application rate, fixation capacity, and mode and intensity
of leaching as variables. Three soils of contrasting texture and fixation
capacity were studied. Leaching of P increased with application rate and inten-
sity of leaching. Constant head leaching resulted in greater movement of
P-32 out of the surface layer and greater accumulation in the leachate than
intermittent leaching. In general, P-32 recovered in the leachate was nonionic
except in instances where maximum leaching occurred. Significant amounts of
P-32 were recovered in the leachate only with sandy loam soil and at the highest
application rate.
72-73:05B-070
FLOOD AND SEEPAGE WATER SAMPLING TECHNIQUES IN RICE FIELDS UNDER DIFFERENT
WATER MANAGEMENT PRACTICES,
Tanji, K. K., Biggar, J. W., Mehran, M., and Henderson, D. W.
California University, Davis.
Soil Science Society of America Proceedings, Vol. 37, No. 3, p 483-485, May-
June, 1973. 3 fig, 1 tab.
(See 72-73:026-109)
72-73:058-071
SELF-DIFFUSION COEFFICIENTS OF SELECTED HERBICIDES IN WATER AND ESTIMATES OF
THEIR TRANSMISSION FACTORS IN SOIL,
Scott, H. D., and Phillips, R. E.
Arkansas University, Agricultural Experiment Station.
Soil Science Society of America Proceedings, Vol. 37, No. 6, p 965-967, Novem-
ber-December, 1973. 1 tab, 11 ref.
Descriptors: *Water pollution sources, *Herbicides, *Diffusion, Weed control,
Inorganic compounds. Inorganic pesticides.
Self-diffusion coefficients of selected herbicides were measured in aqueous
solution by the capillary tube method. The diffusion coefficients were approxi-
mately 0.6 x 10-5 square centimeter per second at 23C and were not particularly
related to the configuration of the herbicide molecule. Values calculated for
the transmission factors of these herbicides differed with the more mobile
compounds being associated with the higher values.
72-73:05B-072
RECOVERY OF N15-LABELED FERTILIZERS IN FIELD EXPERIMENTS.
Westerman, R. L., Kurtz, L. T., and Hauck, R. D.
Illinois University, Department of Agronomy, Urbana.
Soil Science Society of America Proceedings, Vol. 36, No..1, p 82-86, January-
February, 1972. 2 fig, 3 tab, 14 ref.
Descriptors: *Nutrient removal, *Nitrogen, *Leaching, Crop production, Crop
response, Crops, Radioisotopes.
Urea and oxamide, each labeled with N15, were compared as fertilizers in two
field experiments in adjacent locations in successive years with 'Sudax SX111
Sorghum-sudan hybrid as the test crop. Patterns of uptake of fertilizer N
were in accord with the characteristics of the two carriers. In the first
harvests in both experiments the amounts of N taken up from urea were markedly
280
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greater than from oxamide; but by the third harvests, yield responses and N up-
take from oxamide were greater than from urea. Of the N added in urea in the
first experiment, 51% was recovered in the crops and 28% was still in the soil
(0-25cm) at the end of the growing season. Corresponding figures for oxamide
were 52% in the crops and 31% in the soil. In the second experiment, when
fertilizer applications and planting operations were delayed until more favor-
able growing weather, 93% and 99% of the urea- and oxamide-N, respectively,
were estimated as recovered in the crops.
72-73:05B-073
APPLIED AND RESIDUAL NITRATE-NITROGEN EFFECTS ON IRRIGATED GRAIN SORGHUM YIELD,
Onken, A. B., and Sunderman, H. D.
Texas A & M University, Lubbock.
Soil Science Society of America Proceedings, Vol. 36, No. 1, p 94-97, January-
February, 1972. 4 tab, 14 ref.
(See 72-73:026-133)
72-73:056-074
PRIMING EFFECT OF N-15 LABELED FERTILIZERS ON SOIL NITROGEN IN FIELD EXPERIMENTS,
Westerman, R. L., and Kurtz, L. T.
Arizona University, Tucson.
Soil Science Society of America Proceedings, Vol. 37, No. 5, p 725-727, Septem-
ber-October, 1973. 1 tab, 15 ref.
(See 72-73:02G-135)
72-73:056-075
NITROGEN AND PHOSPHORUS LOSSES IN SURFACE RUNOFF FROM AGRICULTURAL LAND AS
INFLUENCED BY PLACEMENT OF BROADCAST FERTILIZER,
Timmons, D. R., Burwell, R. E. , and Holt, R. F.
United States Department of Agriculture, Agricultural Research Service, North
Central Soil Conservation Research Center, Morris, Minnesota.
Water Resources Research, Vol. 9, No. 3, p 658-667, June, 1973. 6 fig, 3 tab,
26 ref.
Descriptors: *Nutrient removal, *Leaching, *Fertilizers, Nitrogen, Phosphorus,
Fallowing, Erosion, Water pollution sources.
Nitrogen (N) and phosphorus (P) losses were determined in the sediment and water
components of surface runoff from fertilized and unfertilized plots on a Barnes
loam soil located in west-central Minnesota. Simulated rainfall was used to
cause surface runoff from small fallow plots that received uniform amounts of
N and P but that had a different placement of the broadcast fertilizer. Deep
incorporation of the fertilizer by plowing down (and subsequent disking) caused
N and P losses about equal to those in surface runoff from unfertilized plots.
The highest nutrient losses occurred when the fertilizer was broadcast on a
disked surface.
72-73:05B-076
MINERAL SPRINGS IN THE SUEZ RIFT VALLEY - COMPARISON WITH WATERS IN THE JORDAN
RIFT VALLEY AND POSTULATION OF A MARINE ORIGIN,
Mazor, E., Nadler, A., and Molcho, M.
281
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Israel Atomic Energy Commission, Nuclear Research Center, Nahal Soreq, Israel.
Journal of Hydrology, Vol. 20, No. 4, p 289-309, December, 1973. 8 fig, 4 tab,
15 ref.
Descriptors: *Water quality, "Water types. Water analysis, Water chemistry,
Water pollution sources.
Fresh and mineral waters from the eastern margin of the Suez Rift Valley are
described. They include a fair number of sources that resemble the mineral
waters in the Jordan Rift Valley. The term Tiberias-Farun water is thus
suggested to describe them. They are characterized compositionally by Cl>Na,
the presence of Nad and MgCl2, a Cl/Br ratio around 150, elevated radium
and H2S content, elevated temperature, a light stable-isotope composition and
high carbon-14 age. The Tiberias-Farun waters are suggested to have originated
from entrapped seawater that gradually changed in composition by interaction
with aquifer rocks. Such changes were demonstrated to take place in the labor-
atory experiments.
72-73:05B-077
NITROGEN NUTRITION AND YIELD RELATIONS OF NUGAINES WINTER WHEAT,
Laopirojana, P., Roberts, S., and Dawson, M. D.
Washington State University, Agricultural Research and Extension center, Prosser.
Agronomy Journal, Vol. 64, No. 5, p 571-573, September-October, 1972. 1 fig,
2 tab, 12 ref.
Descriptors: *Nutrient removal, *Crop response, *Nitrogen, Wheat, Fertility,
Fertilization, Crop production.
A nitrogen rate study was undertaken to determine the potential utility of the
critical nutrient concept as a guide to N fertilization of winter wheat, as
part of a more extensive soil fertility investigation in western Oregon. This
work on wheat was prompted by the need for a suitable diagnostic technique for
determining more precisely the optimum levels of available N. A graph of
grain yield vs N03-N concentration in plant leaves at jointing showed a definite
peak in grain yield at approximately 500 ppm NO3-N in the leaves. Additional
applied N very readily increased leaf NO3-N considerably above 500 ppm and
caused a slight, insignificant drop in grain yield. These results suggest the
applicability of the critical nutrient concept to semidwarf wheat, and provide
justification for additional work to establish more precisely the critical
level for N03-N in wheat.
72-73:058-078
EXPECTATIONS, VARIANCES, AND SENSITIVITY OF NET RETURNS FROM CORN FERTILIZATION
EXPERIMENTS,
Ogut, C., Doll, J. P., Kroth, E. M., and Colyer, D.
Missouri University.
Agronomy Journal, Vol. 64, No. 4, p 515-518, July-August, 1972. 1 fig, 3 tab,
8 ref.
Descriptors: *Nutrient removal, *Crop response, *Nitrogen, Com, Fertility,
Fertilization, Crop production.
A series of experiments measuring corn yield response to applied N and plant
population were conducted at three locations for several years in northern
Missouri. Expected profit functions were estimated for each experiment and the
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input amounts that would have maximized profits for the time period of the
experiments were derived. The resulting amounts were 197 kg of N and 45,360
plants/ha for Grundy County, 140 kg of N and 40,488 plants for Saline County,
and 135 kg of N and 34,455 plants in Boone County. These amounts were lower
than many of the annual optima. Furthermore, expected profits over the experi-
mental periods were relatively insensitive to departures from the annual optima.
Additional analyses determined input rates that (i) minimized the cost or
(ii) minimized the variance of a fixed expected profit level for the period.
72-73:05B-079
INFLUENCE OP NITROGEN, PHOSPHORUS, AND PLANT POPULATION ON YIELD AND QUALITY
OF FORAGE CORN,
Robinson, D. L., and Murphy, L. S.
Louisiana State University, Department of Agronomy, Baton Rouge.
Agronomy Journal, Vol. 64, No. 3, p 349-351, May-June, 1972. 4 tab, 14 ref.
Descriptors: *Corn, *Fertility, *Crop response. Nitrogen, Phosphorus, Nutrient
removal. Crop production, Plant populations.
Irrigated forage corn was grown at five plant populations and five levels each
of N and P at five field locations in central Kansas during a 3-year period to
determine the influence of each variable on yield and quality of forage pro-
duced. An incomplete factorial arrangement of 23 treatments was used in a
randomized complete block design. Multiple regression analyses indicated both
forage and grain yields were significantly affected by N but not by P or plant
population treatments. Treatment variables contributed little to variability
in forage quality as measured by in vitro fermentation and forage fiber analyses.
Nitrogen, cellulose, and lignin concentrations in the forage contributed up to
84?6 of the variation in in vitro dry matter digestibility. These results
indicate that in central Kansas, irrigated corn yields are primarily a function
of the rate of N application, aid that a rather wide range of plant populations
can be tolerated without significantly affecting yield or quality of forage
produced.
72-73:058-080
RECOVERY, RESIDUAL EFFECTS, AND FATE OF NITROGEN FERTILIZER SOURCES IN A SEMI-
ARID REGION,
Power, J. F., Alessi, J., Reichman, G. A., and Grunes, D. L.
Northern Great Plains Research Center, Mandan, North Dakota.
Agronomy Journal, Vol. 65, No. 5, p 765-768, September-October, 1973. 2 fig,
3 tab, 13 ref.
Descriptors: *Nutrient removal, *Leaching, *Nitrogen, Fertilizers, Nitrates,
Crop response. Water pollution sources.
In a field experiment four fertilizer N sources were applied to separate areas
of corn and bromegrass for four years. From the fifth through seventh years,
the two areas were uniformly seeded to barley without additional N fertiliza-
tion, until residual effects were no longer significant. Sources of N used
were ammonium sulfate, ammonium nitrate, calcium nitrate, and urea, applied at
either 55 or 110 kg/ha to Parshall fine sandy loam. Recovery of fertilizer N
in corn plant tops was greatest for ammonium nitrate. Over 35% of the calcium
nitrate and urea applied at 110 kg/ha of N to corn was leached below the root
zone. Leaching of fertilizer N applied to bromegrass was insignificant. Ex-
cept for urea, fertilizer N recovery by bromegrass from the other N sources was
283
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nearly equal and usually higher at 55 kg/ha. Residual growth responses were
smaller from N applied to bromegrass than to corn.
72-73:05B-081
LEACHING LOSSES OF SULFUR DURING WINTER MONTHS WHEN APPLIED AS GYPSUM, ELEMEN-
TAL S OR PRILLED S,
Rhue, R. D., and Kamprath, E. J.
North Carolina State University, Agricultural Experiment Station, Raleigh.
Agronomy Journal, Vol. 65, No. 4, p 603-605, July-August, 1973. 4 fig, 2 tab,
12 ref.
Descriptors: *Sulfates, *Sulfur, Sulfur compounds, Gypsum, Inorganic compounds,
Leaching, Water pollution sources.
Interest has developed in the use of elemental sulfur as a means of maintaining
an adequate supply of sulfur where leaching is a problem. Studies were conduct-
ed with gypsum, finely divided elemental sulfur, and prilled sulfur on a Wagram
loamy sand and a Georgeville silty clay loam to determine the levels of sulfate
sulfur resulting from additions of these sources. Sulfate contents of the 0
to 15-, 15 to 30- and 30 to 45-cm depths were determined at various times
over a period of 200 days after the different sulfur sources were applied in
October. Almost all of the sulfate, that added as gypsum and that resulting
from the oxidation of elemental sulfur, had been leached from the top 45 cm
of the Wagram soil 180 days after application. There was essentially no
movement of sulfate, however, in the Georgeville soil. Very little oxidation
of prilled sulfur appeared to be occurring to any extent in either soil.
72-73t05B-082
RESPONSE OF SUBIRRIGATED BAY MEADOWS TO THE APPLICATION OF NITROGEN, PHOSPHORUS,
AND SULFUR,
Rehm, G. W., Moline, W. J., Sorensen, R. C., and Burzlaf f, D. F.
Nebraska University, Northeast Station, Concord.
Agronomy Journal, Vol. 65, No. 4, p 665-668, July-August, 1973. 4 fig, 7 tab,
7 ref.
Descriptors: *Fertilizers, *Nitrogen, *Phosphorus, Fertility, Hay, Yield
equations.
This study was designed to evaluate the effect of five rates of N, P and S on
the yield and grass-legume composition of subirrigated meadows. Forage yields
were recorded and separations made to determine grass-legume composition.
Yields increased linearly with applied N while the response to P was curvi-
linear. There was no response to S. The percentage of grass in the meadows
increased with applied N. Legume percentages increased with added P. Grass
yields showed a linear increase with applied N and a curvilinear response to
added P. Legume yields decreased linearly at low P rates when high rates of
N were applied but increased curvilinearly as P rates were increased. Through-
out the study, combinations of N and P produced the highest yields, thus demon-
strating the importance of the combination of these two nutrients for maximum
production from subirrigated hay meadows.
72-73:053-083
CATION TRANSPORT IN SOILS AND FACTORS AFFECTING SOIL CARBONATE SOLUBILITY,
284
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Jurinak, J. J., Lai, S. H., and Hassett, j. j.
Environmental Protection Technology Series Report No. EPA-R2-73-235, May 1973.
87 p, 23 fig, 4 tab, 31 ref, append.
Descriptors: *Ion transport, *Calcium carbonate, Leaching, Cation exchange,
Irrigation, Return flow, Chemical precipitation, Hardness (Water), Solutes,
Solubility.
Identifiers: *Solute transport, *Carbonate solubility, Miscible displacement,
Carbonate saturometer.
A predictive model of cation transport in soils undergoing miscible displace-
ment was developed and tested. A mass balance equation was formulated to
include a general nonlinear cation exchange function. The model was applied
to the transport of cations through an exchanger using five types of exchange
functions. The model was further tested by conducting soil column studies which
involved both homovalent and heterovalent exchange. Good agreement between
experimental and predicted data was obtained. Laboratory studies were also
conducted to assess the affect of Mg+2 ion on the solubility of calcareous
materials. Solubility was found to vary with the surface area and mineralogy
of the carbonate material, and the degree of saturation of the water with
respect to a given carbonate mineral. In waters unsaturated with respect to
calcite, Mg+2 generally increased the solubility of calcite. The presence
of Mg+2 decreased the solubility of dolomite in waters which were near satura-
tion with respect to dolomite.
72-73:058-084
NITRATE REDUCTION IN THE VICINITY OF TILE DRAINS,
Davenport, L. A., Lembke, W. D., and Jones, B. A.
Illinois University, Urbana, Department of Agricultural Engineering.
Illinois Water Resources Center, Urbana Research Report No. 64, March 1973.
107 p, 30 fig, 10 tab, 25 ref, 2 append.
Descriptors: *Denitrification, *Drainage, *Nitrates, Porous media, Temperature,
Water pollution control, *Tile drains, Path of pollutants.
Identifiers: *Substrate materials, *Temperature effects, *Methanol.
The fate of nitrates as they travel through a long porous column at a slow
rate was observed in this study with temperature and substrate materials
variable. During a one month period of flow with pore velocities averaging up
to 21 centimeters per day, losses as high as 89 percent were found for a
methanol treatment at 24 degree C while for 13 degree C losses were reduced
to 46 percent. A sawdust substrate material resulted in very little reduction
of nitrate concentrations at 24 degree C and actual increases (presumably from
mineralization) at 13 degree C. Since methanol was found to be an effective
means of removing nitrate from a slowly moving stream of water at temperatures
as low as 13 degree c, it will be used as a standard in future field studies
to evaluate less expensive substrate materials.
72-73:058-085
RATIONALE FOR OPTIMUM NITROGEN FERTILIZATION IN CORN PRODUCTION,
Stanford, G.
United States Department of Agriculture, Agricultural Research Service, Soils
Laboratory, Beltsville, Maryland.
Journal of Environmental Quality, Vol. 2, No. 2, p 159-166, April-June, 1973.
5 fig, 1 tab, 27 ref.
285
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Descriptors! *Fertilizers, *Fertilization, Fertility, Nutrient removal,
Leaching, Nitrogen, Nitrates, Denitrification, Water pollution sources. Ground-
water.
During the past decade, the percentage of the corn acreage in the USA receiving
N fertilizer has risen steadily. By 1971, in the Corn Belt and five adjoining
states, this proportion ranged from 93 to 100% of the total corn acreage.
Between 1964 and 1970 the average rate of N applied to fertilized acres increas-
ed about 83% in the Corn Belt and 128% in adjacent states (Nebraska, Kansas,
Michigan, Wisconsin, and Minnesota). Undoubtedly, there has been an accompany-
ing increase in the proportion of the corn acreage receiving optimum to excess-
ive amounts of N fertilizer. These trends emphasize the importance of develop-
ing improved procedures for achieving optimum fertilizer N use (i.e., adequate
but not excessive rates, and proper timing for greater efficiency) consistent
with the goal of minimizing the possibility of environmental pollution.
72-73:05B-086
WASTE ACCUMULATION ON A SELECTED DAIRY CORRAL AND ITS EFFECT ON THE NITRATE
AND SALT -OF THE UNDERLYING SOIL STRATA,
Chang, A. C., Adriano, D. C., and Pratt, P. F.
California University, Department of Soil Science and Agricultural Engineering,
Riverside.
Journal of Environmental Quality, Vol. 2, No. 2, p 233-237, April-June, 1973.
5 fig, 3 tab, 9 ref.
Descriptors: *Water Pollution Sources, *Animal wastes (wildlife), *Leaching,
Nutrient removal, Dairy industry, Nitrogen, Nitrates.
A corral was selected from a typical Chino-Corona, California area dairy to
study waste accumulation and distribution on corral surfaces and to determine
its effect on underlying soil strata. Waste deposited on the surface tended
to accumulate in a small area of the corral; as much as 57% of the waste was
in an area equaling 30% of the total corral surface. Considerable decomposi-
tion of organic matter and nitrogen loss took place during accumulation; how-
ever, collected waste samples were relatively unstable and subject to further
decomposition. After a long period of dairy operations, leaching of nitrates,
chlorides, and organic matter into soils was substantial. The same order of
magnitude of leaching of chloride and organic carbon occurred throughout the
entire corral surface. The amount of nitrate underneath the area of heavy
waste accumulation was less than that in the other part of the corral. Future
improvement in dairy waste management should take this into consideration in
order to minimize its potential cause of ground water pollution.
72-73:05B-087
NUTRIENT BALANCES FOR THE EVALUATION OF NUTRIENT SOURCES IN WATER QUALITY
MANAGEMENT,
Peters, R. H.
Department of the Environment, Water Quality Branch, Ottawa, Canada.
Water Resources Bulletin, Vol. 9, No. 1, p 49-53, February, 1973. 2 fig,
3 tab, 1 ref.
Descriptors: *Water pollution, *Water quality, *Water quality control. Nutri-
ents, Riverflow, River systems, Leaching.
The methodology for a nutrient balance to evaluate the sources and distribution
286
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of nutrients in a small river basin is described. Loadings for total nitrogen
and phosphorus are calculated from measured nutrient concentration and river
discharge data. Using a special retrieval program and a data storage and
processing system, loadings are accumulated over a given time period to allow
for time of passage through the basin and seasonal changes 'in nutrient distribu-
tion. Nutrient balances are made with the accumulated loadings to obtain the
relative contribution of each nutrient source and the retention of nutrients
within the basin through sedimentation and aquatic growth. The methodology
has been used to study nutrients in the Qu'Appelle River Basin, Saskatchewan,
Canada.
72-73:058-088
RETURN IRRIGATION WATER IN HAWAII,
Young, R. H. P., and Lao, C.
Hawaii University, Water Resources Research Center, Honolulu.
Water Resources Bulletin, Vol. 9, No. 3, p 538-555, June, 1973. 12 fig, 1 tab,
10 ref.
Descriptors: *Water pollution sources, *Nutrient removal, *Fertilizers,
Nitrates, Nitrogen, Groundwater, Hawaii, Sulfates, Domestic water.
Interest in irrigation return water in the Hawaiian Islands has had stimulus
from problems in water quality control by the city and county of Honolulu.
Water quality changes in the basal lens overlain by sugarcane was monitored.
This water is used for domestic supply. The presence of irrigation return
water in the basal lenses was evident. Fertilizer components leach into the
lenses from agricultural fields. Since this water is used for drinking purposes
further studies should be conducted.
72-73:056-089
AN ECONOMIC ANALYSIS OF SELECTED AGRICULTURAL USES OF WARM WATER IN THE PACIFIC
NORTHWEST RESULTING FROM ELECTRIC POWER GENERATION,
Johns, R. W., Folwell, R. J., Dailey, R. R., and Wirth, M. E.
Washington State University, Department of Agricultural Economics, Pullman.
Journal of Environmental Quality, Vol. 2, No. 2, p 224-228, April-June, 1973.
1 fig, 4 tab, 16 ref.
Descriptors: *Water pollution sources, *Thermal pollution, ""Thermal power
plants, *Aquiculture, Greenhouses, Heating, Catfishes, Carp.
Several possibilities are discussed for making use of waste water: aquaculture,
soil heating, and greenhouse heating. Two alternatives were considered for
using cooling reservoirs (i) the production of carp for feed or fish meal,
and (ii) catfish for the fresh market. Soil warming and greenhouse heating
would involve locational problems relative to plant production, processing
facilities, and transportation. None of the uses studied showed clear-cut
advantages in terms of profits which would attract economic investment. Relo-
cating greenhouses in order to use warm water for heating appears to be a
marginal investment. The size of soil-warming systems is limited by the high
initial investment, estimated yield response, and vegetable prices.
72-73:056-090
SUBSURFACE QUALITY TRANSFORMATIONS DURING THE INITIATION OF A NEW STABILIZATION
LAGOON,
287
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Wilson, L. G., Clark, W. I., Ill, and Small, G. G.
Arizona University, Tucson.
Water Resources Bulletin, Vol. 9, No. 2, p 243-257, April, 1973. 3 fig, 3 tab,
15 ref.
(See 72-73:050-010)
72-73s05B-091
QUALITY OF DRAINAGE WATER FROM A HEAVY-TEXTURED SOIL,
Schwab, G. O., McLean, E. O., Waldron, A. C., White, R. K., and Michener, D. W.
Ohio State University, Agricultural Engineering Department, Columbus.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 6,
p 1104-1107, November-December, 1973. 2 fig, 3 tab, 11 ref.
Descriptors: *Water pollution sources, *Runoff, *Leaching, Nutrient removal,
Agricultural chemicals, Erosion, Nitrogen, Phosphorus, Drainage.
Sediment, dissolved solids, nine chemical elements or ions, five pesticides,
electrical conductivity, pH, and BOD in tile drainage effluent and in surface
runoff were measured from one-half acre plots on Toledo silty clay soil near
Sandusky, Ohio, for a 3-year period, 1969-1971. Measurements were taken from
both conventional tilled and no-tilled plots in continuous corn. Irrigation
water was applied each year to simulate heavy rainfall. Recommended fertilizer
amounts were applied, but pesticide kinds and amounts were greater than normally
required for insect or weed control. Rainfall was above average in 1969 and
1970, and below average in 1971. Sediment losses from the tile and surface
drainage water were several times greater for conventional tillage than for no
tillage.
72-73:058-092
INFILTRATION AND LANDFILL BEHAVIOR,
Rovers, F. A., and Farquhar, G. J. .
Waterloo University, Waterloo, Ontario, Canada.
Journal of the Environmental Engineering Division, American Society of Civil
Engineers, Vol. 99, No. EE5, p 671-690, October, 1973. 7 fig, 8 tab, 33 ref.
Descriptors: ^Environmental engineering, *Landfills, Sanitary engineering,
Infiltration, Leaching, Absorption, Evaporation, Gases, Methane, Temperature,
Thawing.
The effects of infiltration on sanitary landfill leachate and gas production
were examined under both field and laboratory conditions. Maximum field leach-
ate production occurred during spring thaw. Production was greatly reduced
during the summer. Moisture adsorption prior to leachate flow ranged from
10.0 cm/m to 14.2 cra/m of compacted refuse. The leachate produced was strong.
As an indication, concentrations of COD, calcium, chloride and ammonia nitrogen
exceeded 40,000 mg/1, 2,500 mg/1, 1,200 mg/1, and 600 mg/1, respectively.
Decomposition proceeded anaerobically with the production of methane and carbon
dioxide. Periods of rapid moisture influx were accompanied by increased
leachate strength, reduced pH, and decreased methane production thus allowing
the accumulation of organic acids and subsequent reductions in pH. The inter-
ference appeared to have arisen from an increase in oxidation-reduction poten-
tial.
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72-73:058-093
LEACHATE TREATMENT BY COAGULATION AND PRECIPITATION,
Thornton, R. J., and Blanc, F. C.
Camp, Dresser, and McKee Incorporated, Boston, Massachusetts.
Journal of the Environmental Engineering Division, American Society of Civil
Engineers, Vol. 99, No. EE4, p 535-544, August, 1973. 2 fig, 5 tab, 9 ref.
Descriptors: *Land fills,, *Sanitary engineering, *Leaching, Water quality.
Chemical precipitation. Environmental engineering, Coagulation, Solid wastes.
When sanitary landiflls are constructed with provisions for collection and
treatment of leachates, chemical treatment may be one of the treatment processes
employed. The research was conducted to determine the ability of chemical
treatment to remove suspended solids, biochemical oxygen demand, chemical
oxygen demand, iron, calcium,' and magnesium from leachate. Chemical treatment
studies were conducted in the laboratory using alum, lime, and ferric chloride.
Preliminary results indicate that lime precipitation was most effective. Addi-
tional studies revealed that suspended solids, color, and some multivalent
cations can be effectively removed from raw leachate using lime. However,
significant removals of soluble biochemical oxygen demand were not observed
and extremely high lime concentrations in the 300 mg/1 600 mg/1 range were
required to obtain a relatively clear supernatant resulting in relatively
large amounts of sludge.
72-73:05B-094
HERBICIDE CONTAMINATION OF SURFACE RUNOFF WATERS,
Evans, J. O., and Duseja, D. R.
Utah State University, Logan, Department of Plant Science.
Environmental Protection Agency, Technology Series Report, EPA-R2-73-266, June
1973. 99 p, 14 fig, 22 tab, 62 ref.
Descriptors: *Herbicides, *Weed control. Water pollution sources, Persistence,
Urea pesticides, Triazine pesticides, 2 4-D, 2,4,5-T, *Return flow, Path of
pollutants. Water quality control.
Identifiers: *Herbicide runoff, *Picloram adsorption, Picloram leaching,
Herbicide residues, Herbicide adsorption. Canal bank weed control, Diuron,
Picloram.
Field and laboratory studies of the movement of herbicides were conducted to
determine their potential as contaminants in irrigation return flow. Special
emphasis was given to the use of herbicides for vegetation control along ditches,
canals and watersheds where high dosages are required to control the excessive
growth of grasses and broadleaved weeds. The following herbicides have been
studied: substituted urea (diuron), triazines (summitol and atrazine), pheno-
xyacetic acid (2,4-D and 2,4,5-T) and a substituted pyridine (picloram). The
greatest tendency for transport of herbicides in water coming in contact with
soils occurs during the initial storms following spray application. If the
intensity of the initial precipitation is not sufficient to cause movement
across the soil, the danger of herbicide movement is essentially eliminated.
The highest concentrations (ppm) of herbicide observed in surface waters were
1.8, 0.5, 4.2, 1.2 and 2.7 for diuron, summitol, 2,4-D, 2,4,5-T and picloram,
respectively. These levels were observed immediately below treated areas
receiving the higher recommended dosages of the herbicides. All herbicide.
concentrations dropped below the limit of detection within a few hundred meters
below the sprayed areas. Presumably, soil filtration, adsorption and dilution
are primarily responsible for the loss of herbicides from water.
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72-73:05B-095
SIGNIFICANCE OF MAN-MADE SOURCES OF PHOSPHORUS: FERTILIZERS AND FARMING,
Cooke, G. W., and Williams, R. J. B.
Rothamsted Experimental Station, Harpenden (England).
Water Research, Vol. 7, Nos. 1/2, p 19-33, January-February 1973. 9 tab,
26 ref.
Descriptors: *Phosphates, Water pollution sources, "Agricultural runoff,
Fertilizers, Livestock, Erosion, Leaching, Animal wastes (Wildlife), Path of
pollutants. Nutrients, Water pollution control, Runoff, *Farm wastes, Cattle,
Hogs, Sheep, *Phosphorus, "Poultry.
Identifiers: England.
There are three ways which phosphorus from agricultural areas can enter natural
water supplies: in drainage water; in eroded soil; or from animal excreta.
Study of these sources showed that in most cases runoff from agricultural
lands contained less P than the receiving waters. However, where erosion
occurs, P levels in water may be increased since fertilizers tend to fix
themselves to topsoil which is lost first. The P in muds is solubilized in
anaerobic reducing conditions and becomes available to rooted plants and
microorganisms. Most animal excreta is reapplied to land as fertilizer and may
occasionally pollute streams if it is improperly applied or if heavy rains
occur. In addition, new methods of handling excreta as slurries increase
the potential of pollution by over application or leakage of storage tanks.
One source of phosphorus in natural waters which is often not considered is
wild birds. These may add significantly to P levels in water. At present,
it appears that agricultural sources add little P to natural waters. However,
steps must be taken to assure that the three potential sources are adequately
controlled.
72-73:053-096
THE ACCELERATION OF THE HYDROGEOCHEMICAL CYCLING OF PHOSPHORUS,
Stumm, W.
Eidgenoessische Anstalt fuer Wasserversorgung, Abwasserreinigung und Gewaesser-
schutz, Zurich (Switzerland).
Water Research, Vol. 7, Nos. 1/2, p 131-144, January-February, 1973. 9 fig,
2 tab, 27 ref.
Descriptors: *Water pollution sources, "Phosphorus, "Cycling nutrients, Ferti-
lizers, Oxygen demand, Limiting factors, Sediments, Water pollution effects,
Phosphates, Nutrients, Water pollution control, Animal wastes. Farm wastes.
Detergents, Municipal wastes. Lakes, Agricultural runoff, Oceans, Rivers.
Identifiers: Fate of pollutants, Mobilization, Phosphorites, Phosphorus cycle.
By mining phosphorus in progressively increasing quantities, man disturbs the
ecological balance and creates undesirable conditions in inland waters, estuar-
ies and coastal marine waters. The civilizatory increase in phosphorus supply
to the oceans although of little consequence to the oxygen reserves of the deep
sea, augments markedly the marine environments with intermittent or permanent
oxygen deficient conditions. Because most aquatic food resources are produced
in estuaries and coastal areas, the deterioration in water quality of these
regions decreases the potential harvest of marine animal protein. Present
agricultural practice of excessively fertilizing land needs to be reexamined;
present agricultural technology must not without modification be exported to
tropical areas. Present drainage systems for sewage, industrial wastes and
storm water runoff accelerate the transport of nutrients and other pollutants
to the rivers and the sea; waste plants are remarkable inefficient in mitigating
this civilizatory flux.
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72-73:058-045
WATER-LEACHABLE NUTRIENTS FROM FROZEN OR DRIED PRAIRIE VEGETATION,
White, E. M.
South Dakota State University, Plant Science Department, Brookings.
Journal of Environmental Quality, Vol. 2, No. 1, p 104-107, January-March,
1973. 1 fig, 4 ref.
Descriptors: *Water pollution sources, *Runoff, Nitrogen, Phosphorus, Calcium,
Magnesium, Nutrient removal, Leaching, Prairie soils, Vegetation.
Runoff from agricultural lands in South Dakota is mainly from melting snow and
spring rains. Nutrient enrichment of this water may be enhanced during the
fall and winter by the rupturing of plant cells by freezing. Native prairie
vegetation and mulch were sampled in late summer, early fall, and spring to
determine the effect freezing, in comparison to drying, would have on nutrient
release to water. Release of Ca, Mg, K, P, N03-N, and NH4-N by freezing was
related to stage of growth or decomposition of the vegetation. Freezing in
creased nutrient release if the vegetation were growing when it was frozen.
Soil genesis, ecological relations between plant species, and runoff water
quality could be affected by the relative release of different kinds of
nutrients.
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Section XXIV
WATER QUALITY MANAGEMENT AND PROTECTION
EFFECTS OF POLLUTION (Group 05C)
72-73:05C-001
CARBON CYCLE IN SEDIMENT-WATER SYSTEMS,
Kerr, P.C., Brockway, D.L., Paris, D.F., and Craven, S.E.
National Environmental Research Center, Corvalis, Oregon.
Journal of Environmental Quality, Vol 2, No 1, p 46-52, January-March 1973.
1 fig, 72 ref.
Descriptors: *Reviews, *Carbon cycle, *Aquatic environment, *Sediment-water
interfaces, *Aguatic microorganisms, Carbon dioxide, Sinks, Ecosystems,
Adsorption, Sediments, Anaerobic bacteria, Aerobic bacteria, Algae, Aquatic
productivity, Cycling nutrients, Aerobic conditions, Anaerobic conditions,
Biodegradation, Path of pollutants, Secondary productivity, Carbon,
Nutrients, Organic matter, Nitrogen, Phosphorus, Sorption, Clay minerals,
Fungi, Yeasts, Phosphates, Carbonates, Primary productivity, Hydrogen ion
concenctration. Methane, Photosynthesis, Benthos, E. coli, Bioindicators,
Degradation (Decomposition), Organic acids, Sedimentation, Metabolism,
Bicarbonates, Bottom sediments.
Identifiers: Nutrient interchange, Mineralization, Heterotrophy, Organic
carbon, Substrate utilization, Autotrophic nutrition, Heterotrophic nutrition.
Literature relevant to the extent and rate of carbon exchange between
sediment and water is reviewed and the general implication of the role of
carbon in regulating biological activity is discussed. Several conclusions
are drawn from the review. The extent of adsorption of organics to clay min-
erals in natural aquatic ecosystems is not known. Sorption, desorption,
sedimentation, and aerobic and anaerobic activity are affected by physical
factors such as depth and mixing. Certain data indicate that organisms
cannot utilize organic material sorbed to clay minerals; other data indicate
that growth of certain bacteria and yeast is stimulated by the addition of
clay minerals. Although the exact substrate (s) is not known, aerobic and
anaerobic decomposition of organic materials occurs in and on sediments.
Aerobic decomposition seems to result in three different reactions affecting
sediment-water carbon exchange: (1) Methane gas is produced and released
from sediments. (2) Organic acids produced by anaerobes can serve as car-
bon sources for aerobes as well as aiding in solubilization of carbonates
and affecting sorptive processes. (3) Carbon dioxide produced by anaerobes
may be combined in some manner and remain in the sediments. The fact that
most deep sediments retain organic carbon indicates that sediments may be
sinks for organics. Possible sediments serve as organic carbon sinks
simply because the rate of sedimentation exceeds the rate of decomposition.
72-73:05C-002
THE NITROGEN CYCLE IN SEDIMENT-WATER SYSTEMS,
Keeney, D.R.
Wisconsin University, Madison, Department of Soil Science.
Journal of Environmental Quality, Vol 2, No 1, p 15-29, January-March 1973.
6 fig, 6 tab, 199 ref.
Descriptors: *Reviews, *Aquatic productivity, *Sediment-water interfaces,
*Nitrogen cycle, Sutrophication, Environmental effects, Cycling nutrient,
Nitrification, Dentrification, Nitrogen fixation, Water quality, Ecosystems,
Algae, Bacteria, Biomass, Nitrogen, Sediments, Water temperature, Cyanophyta,
Anabaena, Aquatic soils, Mineralogy, Soil properties, Lake morphology, Hydro-
gen ion concentration. Dissolved oxygen, Oxidation-reduction potential.
Nutrients, Lakes, Electrodes, Respiration, Bacteria, Plankton, Incubation,
Pseudomonas.
Identifiers: Mineralization, Immobilization, Ammonification, Nutrient inter-
change, Fate of pollutants, Anerobic respiration, N-15 Lake Mendota, Bantam
Lake, Green Lake, Lake Kinneret, Nitrobacter, Bacillus, Achromobacter, Micro-
cocus, Nitrosomonas europea, Clostridium pasteurinanum.
292
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The available literature on the fate of nitrogen in waters and sediments is
reviewed. Emphasis is placed on the importance of N to aquatic productivity,
the pathways leading to N gains or losses in aquatic ecosystems, and the
availability of N in sediments to the overlying waters, important biological
reactions include N mineralization and immobilization, nitrification and
denitrification, and N fixation. The effect of sediment properties, lake
morphology and environmental factors.(pH, temperature, dissolved oxygen,
oxidation-reduction) on the pathways and rates of N turnover are considered.
The mixing process in sediments appear to be the most important in releasing
sediment-N to waters. Several facets of the N cycle in waters and sediments
require further elucidation. Research needs are outlined.
72-73:050-003
MICROBIOLOGICAL QUALITY OF SURFACE DRAINAGE WATER FROM THREE SMALL IRRIGATED
WATERSHEDS IN SOUTHERN IDAHO,
Smith, J.H. and Douglas, C.L.
Agricultural Research Service, Kimberly, Idaho. Snake River Conservation
Research Center.
Journal of Environmental Quality, Vol 2, No 1, p 110-112, January-March 1973.
2 tab, 8 ref.
Descriptors: *Water quality, *Irrigation effects, *Coliforms, *Enteric
bacteria, Water analysis, Water pollution effects, Irrigation water, Water
pollution, Streptococcus, Pathogenic bacteria, Filtration, Separation tech-
niques, Pollutant identification, Surface runoff, Idaho, Dissolved oxygen,
Biochemical oxygen demand, Water temperature.
Identifiers: *Fecal streptococci, *Fecal coliforms, Most probable number
test, Standard methods.
Irrigation water applied to and leaving three small watersheds in southern
Idaho was analyzed to determine t:he influence of surface irrigation on
bacteriological quality of surface runoff water. The sites were inhabited
by families raising various crops and some livestock. Presumptive, confirmed
and completed coliform counts were made according to Standard Methods, MPN's
were calculated, fecal coliform counts were made by MPN analyses, and fecal
streptococci were determined by micropore filtrations. DO, BOD, and water
temperatures were also determined. The irrigation water samples were polluted
with microorganisms associated with human and animal wastes, as indicated
by numbers of coliforms and by fecal coliform/fecal streptococci ratios.
There was a trend toward increasing numbers of coliforms and fecal coliforms
in the drainage water compared to the irrigation water, but the differences
were generally within the confidence limits for MPN analyses. On two of
the three watersheds, microorganisms incubated on plating agar at 20C had
higher counts in the drainage than in the irrigation water. Fecal strepto-
cocci numbers were significantly higher in the drainage than in the irrigation
water on two of the three small watersheds. Even though microorganisms
counts tend to be higher in drainage than in the irrigation water on these
three small watersheds, irrigation use has a minimal deleterious effect on
the microbiology of these waters*'
72-73:05C-004
NITROGEN, PHOSPHORUS AND OTHER INORGANIC MATERIALS IN WATERS IN A GRAVITY-
IRRIGATED AREA,
Fitzsimmons, D.W., Lewis, G.C., Naylor, D.V.
Idaho University, Moscow. Department of Agricultural Engineering; and
Idaho University, Moscow. Department of Soils.
Transactions of the American Society of Agricultural Engineering, Vol 15,
No 2, P 292-295, 1972. 5 fig, 5 tab, 12 ref.
The kinds and amounts of inorganic materials were determined in surface
and groundwaters in an intensively-farmed gravity-irrigated area (Boise
Valley, Idaho). Water samples, taken throughout the crop growing season
were analyzed for nitrate-nitrogen, ammonia, and organic nitrogen, two forms
of phosphorus, and total solids. Water samples were collected at 2-week
intervals throughout the 1970 season from 79 sites which included 29 farms
in four irrigation districts. The mean concentrations of all three forms of
293
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nitrogen were found to be relatively low. The mean concentration of each
nitrogen form was greater in the surface runoff than in the headwater;
the groundwater contained more nitrate-nitrogen than the other water sources,
possibly an indication that nitrate is being leached from the soil by perco-
lating irrigation water; this material could also come from feedlots,
dairies and septic tank drain fields in the area. The surface runoff also
contained the largest concentrations of total phosphorus and total solids.
The groundwater was found to contain a relatively large concentration of
both ortho and total phosphorus.
72-73:050005
ON THE NECESSARY AND SUFFICIENT FOR A LONG-TERM IRRIGATED AGRICULTURE,
Moore, C.V.
United States Department of Agriculture, Davis, California.
Water Resources Bulletin, Vol 8, No 4, p 802-812, August, 1972. 3 fig,
12 ref.
(See 72-73:058-032)
72-73:05C-006
SALINITY-OZONE INTERACTIONS ON PINTO BEANS: INTEGRATED RESPONSE TO OZONE
CONCENTRATION AND DURATION,
Maas, E.V., Hoffman, G.J., Rawlins, S.L., and Ogata, G.
United States Department of Agriculture, Riverside, California.
Journal of Environmental Quality, Vol 2, No 3, p 400-404, July-September,
1973. 2 fig, 2 tab, 13 ref.
(See 72-73:03C-005)
72-73:05C-007
INTERACTIVE EFFECTS OF SALINITY AND OZONE ON GROWTH AND YIELD OF GARDEN
BEET ,
Ogata, G. and Maas, E.V.
United States Department of Agriculture, Riverside, California.
Journal of Environmental Quality, Vol 2, No 4, p 518-520, October-December,
1973. 2 tab, 12 ref.
(See 72-73:03C-006)
72-73:05C-008
LEACHING REQUIREMENT STUDIES: SENSITIVITY OF ALFALFA TO SALINITY OF IRRI-
GATION AND DRAINAGE WATERS,
Bernstein, L. and Francois, L.E.
United States Department of Agriculture, Agricultural Research Service,
Salinity Laboratory, Riverside, California.
Soil Science Society of America Proceedings, Vol 37, No 6, p 931-943,
November-December, 1973. 4 fig, 10 tab, 17 ref.
Descriptors: *Salt balance, *Crop response, Leaching, Alfalfa, Lysimeters,
Irrigation practices, Sodium, Drainage engineering.
Alfalfa was grown in 0.6 by 1.5 m greenhouse lysimeters and irrigated with
two waters of EC 1 and 2 mmho/cm prepared by adding equivalent amounts of
NaCl and CaC12 to a 0.4 mmho/cm tap water. Yields showed relatively little
effect of leaching fraction (LF) within the limits consistent with steady-
state salt balance for suction-drained lysimeters but decreased 26% at the
lowest Lf for gravity-drained lysimeters. Yields with the 2 mmho/cm
irrigation water treatments were consistently about 10% less than those
with the 1 mmho/cm water. Cessation of leaching or reduciton of LF to
levels requiring drainage water salinities for salt balance at steady
state to exceed 35 mmho/cm, the maximum salinity achievable by alfalfa
roots, eventually reduced yields. Yields were significantly higher when
leaching was done every third or sixth irrigation than in every irrigation
while maintaining the same average LF of 1/32 and 1/16 for the 1 and 2 mmho/cm
irrigation waters, respectively.
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72-73:050-009
CELL WALL PROPERTIES OF COTTON ROOTS AS INFLUENCED BY CALCIUM AND SALINITY,
Gerard, C.J. and Hinojosa, E.
Texas A&M University, Agricultural Research and Extension Center, Weslaco.
Agronomy Journal, Vol 65, No 4, p 556-560, July-August, 1973. 11 fig, 1 tab,
15 ref.
Descriptors: *Salinity, *Crop response, Calcium, Root development, Cotton,
Root system, Root zone.
Research was conducted to determine the influences of salinity and Ca uptake
on cell wall properties of cotton roots. It was postulated that examination
of cell wass properties might give insight on the role of Ca in moderating
the influences of salinity and toxic ions on cellular stability and plant
growth. Age and Ca are exxential to the development of thick cell walls
in the stele. Thick cell walls exhibit high birefringence under polarized
light. Salinity reduced Ca uptake and concentration of cotton roots. Xylem
and phloem cell wall's of cotton roots grown in solutions with sufficient Ca
and low salinity thickened and in about 70 hours, exhibited high bire-
fringence. Young cell walls in the pericycle or laterals did not exhibit
birefringence. Even at adequate level of Ca, salinity retarded the develop-
ment of thick cell walls and high birefringence in the stele to about 140
hours.
72-73:05C-010
ENVIRONMENTAL INDICATORS FOR PESTICIDES,
Strickland, J. and Blue, T.
Stanford Research Institution, Menlo Park, California
Avaliable from the National Technical Information Service as PB-210, 666,
Prepared for Council on Environmental Quality, April 1972. 123 p, 8 fig,
15 tab. SRI Project No. ECU-1608 Contract No. EQC217.
Descriptors: *Pesticide residues, *Water pollution effects, *Monitoring,
*Transportation, *Path of pollutants, *Lakes, *Rivers, *Estuaries, Fish,
Public health, Wildlife, Rain, Water pollution sources, Pesticides, Insecti-
cides, Herbicides, Fungicides, Industrial production, Storage, Air, Water
pollution, Soils, Foods, Food chains, Chlorinated hydrocarbon pesticides,
Mercury, Metals, Heavy metals, Phenols, Copper, Copper sulfate, 2,4,5-T, 2,4-D
Precipitation (Atmospheric),Aldrin, DDT, Dieldrin, Endrin, Heptachlor,
Carbamate pesticides, Organophosphorus pesticides. Runoff, Ponds,
Swamps, Streams, Oceans, Absorption, Fishkill, Toxicity, Phosphothioate
pesticides.
Identifiers: Pentachlorophenol, Parathion, Chloredane, Heptachlor epoxide,
Lindane, Methoxychlor, Toxaphene.
Results are presented from a study concerned with environmental indicators
of pesticides. The indicators include consideration of: (1) Production,
imports, exports, and consumption of pesticides by type and overtime,
(2) amounts of pesticides found in food, air, water, soil, wildlife,
plants, and the human body, and (3) indirect measures of pesticide utili-
zation as they relate to public health, crop quality and yield, and recrea-
tional and aesthetic values. Steps are identified which should be taken
for future collection and processing of the data necessary for caluclation
of these indicators at appropriate intervals. A comprehensive framework
was developed which characterizes the modes by which materials move, the
mediums affected, the ecological phenomena that can be observed, and the
environmental factors concerned. Recommendations are included for effectively
orienting and managing pest control programs with maximum environmental
enhancement.
72-73:05C-011
SALINITY-OZONE INTERACTIVE EFFECTS ON YIELD AND WATER RELATIONS OF PINTO
BEANS,
Hoffman, G.J., Maas, E.V., and Rawlins, S.L.
United States Department of Agriculture, Riverside, California
Journal of Environmental Quality, Vol 2, No 1, p 148-158, January-March, 1973.
295
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4 fig, 2 tab, 16 ref.
(See 72-73:030-009)
296
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Section XXV
WATER QUALITY MANAGEMENT AND PROTECTION
WASTE TREATMENT PROCESSES (Group 05D)
72-73:050-001
BEST COMBINATION OF WASTE TREATMENT AND SPATIALLY DISTRIBUTED DISCHARGE OF
EFFLUENT,
Mendiratta, A. K., and Davidson, B.
Rutgers - The State University, New Brunswick, New Jersey, Department of
Chemical Engineering; and Rutgers - The State University, New Brunswick, New
Jersey, Department of Biochemical Engineering.
Water Resources Research, Vol. 8, No. 3, p 565-585, June, 1972. 10 fig, 3 tab,
31 ref.
Descriptors: *Waste water treatment, *Water quality control, *Effluents,
*Biochemical oxygen demand, *Dissolved oxygen, Distribution, Standards, River
basins, Planning, Optimization, *Mathematical models. Systems analysis. Pipe-
lines, Networks.
Identifiers: *Water quality management, Optimal control theory, Stream quality
standard.
The optimal control theory based on Pontryagin's minimum principle has been
applied to the problem of specifying the best combination of minimum percent
BOD waste treatment and effluent distribution policies for a single plant on
a specified polluted river segment. The analysis features a new dual water
quality stream standard consisting of a minimum allowable DO concentration at
every point in the river segment combined with a maximum allowable BOD concentra-
tion at a specified downstream point. The optimal BOD effluent distribution
policies are compared with choice suboptimal effluent discharge patterns
associated with best single point, best uniform, and best bang-bang injection
policies. The inequality constraints, the nonlinearities in the system model,
and the synthesis of the optimal controls were handled in a direct manner by
using the Pontryagin control theory principle combined with gradient search
and penalty function techniques. The results establish certain guidelines for
increasing the assimilative capacity of a given river segment through judicious
combinations of minimum percent BOD waste treatment and continuous BOD effluent
distribution or dumping patterns associated with single plant effluents. Cer-
tain cost factors associated with the pipeline distributer network and treatment
plant could be incorporated directly into the optimization algorithm.
72-73:050-002
DELINEATION OF AREAS FOR TERRESTRIAL DISPOSAL OF WASTE WATER,
Bond, J. G., Williams, R. E., and Shadid, O.
Idaho Bureau of Mines and Geology, Moscow.
Water Resources Research, Vol. 8, No. 6, p 1560-1573, December, 1972. 9 fig,
11 ref.
Descriptors: *Waste water treatment, *Sprinkler irrigation, Groundwater,
Groundwater movement, Water table aquifers. Shallow water, Idaho, Irrigation,
Basalts, Fertilization, Water quality, Hydrogeology, Hydrologic aspects,
Hydrologic systems, *Water reuse, *Waste water disposal.
Identifiers: Renovation (Wastewater), Snake River Basin.
Renovation of waste-water, particularly with respect to organic and nutrient
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constituents, through irrigation with coincidental crop fertilization and
groundwater recharge is proposed for hydrogeologically suitable portions of
the Snake River plain, instead of expensive tertiary or sometimes secondary
treatment. The region near Idaho Falls and Blackfoot has been used as a case
study area to establish the methodology for selecting the most suitable terres-
trial disposal sites. Safeguarding surface water and groundwater resources,
providing for maximum probability of proper renovation of waste water, and
minimizing design and supervision requirements are conditions that must be
satisfied by any terrestrial waste water disposal project. The criteria for
selecting sites that meet these conditions for proper disposal and renovation
include gently sloping topography, a thick subsurface section of unconsolidated,
unsaturated porous medium, a surficial mantle of high sand-silt content, and a
well-understood shallow groundwater flow system. When evaluation and mapping
apply to these criteria in the area around Idaho Falls and Blackfoot, the
delineation of sections of land where successful terrestrial disposal of
waste water can be expected is facilitated.
72-73:05D-003
METHODS FOR APPORTIONING COSTS AMONG PARTICIPANTS IN REGIONAL SYSTEMS,
Giglio, R. J., and Wrightington, R.
Massachusetts University, Amberst, Department of Industrial Engineering.
Water Resources Research, Vol. 8, No. 5, p 1133-1144, October, 1972. 17 ref.
Descriptors: *Cost sharing, *Waste water treatment, *Water pollution, treat-
ment facilities, "Linear programming, Separable costs, Benefits, Regional
analysis. Mathematical models, Systems analysis. Optimization.
Identifiers: Gaming-theory, Bargaining methods. Economic analysis.
Five methods for apportioning the costs of joint or regional waste water treat-
ment facilities among users are discussed. It is assumed that polluters will
clean their wastes and pay directly at least a fraction of the costs of
treating their wastes. The methods examined are: (1) Cost sharing based on
the measure of pollution; (2) cost sharing based on single plant costs with a
rebate proportional to the measure of pollution; and (3) cost sharing based on
the separable costs remaining benefit method; the two additional methods
rely on game-theory; (4) cost sharing based on free market bargaining; and
(5) cost sharing based on bargaining including the regional authority as a
participant, using linear programming. Using numerical and theoretical argu-
ments it is demonstrated that often methods 1-3 do not provide an apportion-
ment that satisfies all people involved and that a potential participant may
find it economically advantageous not to join the regional plan, possibly
forcing the adoption of a more costly system. These difficulties will fre-
quently arise when any plan is subjected to the pressures of free market
bargaining. Methods 4-5 are introduced to deal with this problem. The bar-
gaining methods prove that some cost-sharing problems have no unique solutions
and that others have no viable solution at all unless the regional authority
can obtain a subsidy.
72-73:050-004
DEEP PLOWING - AN ENGINEERING APPRAISAL,
James, P. E., and wilkins, D. E.
United States Department of Agriculture, Beltsville, Maryland.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 3,
p 420-422, May-June, 1972. 5 fig, 4 tab, 4 ref.
(See 72-73:08C-001)
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72-73:05D-005
EVALUATION OF CURRENT TECHNIQUES FOR NUTRIENT REMOVAL FROM WASTEWATERS,
Shindala, A.
Mississippi State University, Department of Civil Engineering.
Water Resources Bulletin, Vol. 8, No. 5, p 987-998, October, 1972. 32 ref.
Descriptors: *Waste treatment, *Saline water, *Drainage water, *Nutrient
removal, Nitrogen compounds, Phosphorus compounds, Denitrification, Water
treatment, Water quality control, Water pollution treatment, Eutrophication.
A comprehensive evaluation of current techniques for removal of nitrogen and
phosphorus was conducted. Extensive searchings of the literature demonstrated
that the technology is available to provide effective nutrient removal at a
reasonable cost. Current methods for phosphorus removal include biological,
chemical precipitation, and ion exchange. Nitrogen removal processes include
biological denitrification, ammonia stripping, and ion exchange. This paper
consists of a brief summary of the work. A copy of the complete work is
available from the author.
72-73:050-006
ABSORPTION OF MERCURIC CATION BY TANNINS IN AGRICULTURAL RESIDUES,
Waiss, A. C., Jr., Wiley, M. E., Kuhnle, J. A., Potter, A. L., and McCready,
R. M.
United States Department of Agriculture, Agricultural Research Service, Western
Regional Research Laboratory, Berkeley, California.
Journal of Environmental Quality, Vol. 2, No. 3, p 369-371, July-September,
1973. 5 tab, 15 ref.
Descriptors: *Water pollution treatment, *Cation adsorption, Heavy metals,
Mercury, Chelation, Oxidation, Reduction.
Two common environmental pollutants are agricultural residues and waste streams
of water containing only traces of heavy metals (such as mercury at 10 or more
ppb) from mining or manufacturing operations. Agricultural residues contain
tannins, polyphenolic substances, pectin, and other polymers - all with
chemically reactive groups that can chelate, reduce, oxidize, demonstrate ion
exchange properties, and aid in removing traces of heavy metals from dilute
waste water streams at low cost. Finely ground and water-washed agricultural
residues were slurried in water and packed into columns for absorption tests
with heavy metals. Solutions of known concentrations of heavy metals were
passed through the packed columns which were then eluted with water or with
alkaline or acidic solutions. The fractions and the column absorbents were
then analyzed by standard atomic absorption methods. The nature of the physical
and chemical forces that are effective in metal absorption from agricultural
residues is not clear.
72-73:050-007
EFFECTS OF SURFACE IRRIGATION WITH DAIRY MANURE SLURRIES ON THE QUALITY OF
GROUNDWATER AND SURFACE RUNOFF,
Barker, J. C., and Sewell, J. I.
Tennessee University, Agricultural Engineering Department, Knoxville.
Transactions of the American Society of Agricultural Engineers, Vol. 16, No. 4,
p 804-807, July-August, 1973. 1 fig, 4 tab, 9 ref.
Descriptors: *Water pollution sources, *Agricultural runoff, Feedlot, Dairy
299
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industry. Waste treatment. Waste disposal, Runoff, Groundwater, Water quality.
An experimental manure slurry irrigation system was established at the Univer-
sity of Tennessee Khoxville Cherokee Dairy Farm to study this waste management
problem. This system requires land on which to irrigate with the slurry. The
quantities of manure and wastewater which pastures and cropland can receive
without polluting groundwater, surface water, and the land itself have generally
not been established. The major objectives were to determine the effects of
slurry irrigation on surface runoff and groundwater quality and to develop
techniques for irrigating with dairy manure slurry. A 4acre plot with ground
slopes varying from about 20 percent to almost flat was selected as a manure
slurry saturation area to study the effects of the surface spreading of this
slurry on the quality of groundwater and surface runoff. Three groundwater
wells extending approximately 50 feet below the ground surface were drilled
in the vicinity of the saturation area.
72-73:05D-008
OPTIMAL CONTROL OF NITROGEN LOSSES FROM LAND DISPOSAL AREAS,
Haith, D. A.
Cornell University, Agricultural Engineering Department, Ithaca, New YQrk.
Journal of the Environmental Engineering Division, American Society of Civil
Engineers, Vol. 99, No. EE6, p 923-937, December, 1973. 4 fig, 6 tab, 28 ref.
Descriptors: *Sewage treatment, *Sewage disposal, *Water pollution sources,
Nitrogen, Leaching, Runoff, Sewage effluents. Waste water disposal, Soil fil-
ters.
The land disposal alternative is not free from water pollution potential.
Nitrogen losses from percolation and runoff may contaminate water supplies and
contribute to the eutrophication of aquatic systems. A general model of the
soil nitrogen budget has been developed for the purpose of comparing alternative
strategies for controlling nitrogen leaching losses from a cropped land disposal
area. The model is based on monthly inventory equations for both inorganic
and organic soil nitrogen and includes the processes of plant nitrogen uptake,
mineralization of organic nitrogen, and leaching. The model was tested using
nitrogen budget data from several New York corn production field studies. The
model was linearized and linear programming was used to find monthly disposal
schedules that maximize annual returns from a sewage sludge disposal system
subject to constraints on nitrogen leaching losses.
72-73:050-009
PROCESS KINETICS FOR DENITRIFICATION,
Johnson, W. K.
Minnesota University, Department of Civil and Mineral Engineering, Minneapolis.
Journal of the Sanitary Engineering Division, American Society of Civil Engi-
neers, Vol. 98, No. SA4, p 623-634, August, 1972. 3 fig, 1 tab, 29 ref.
Descriptors: *Sewage treatment, *Activated sludge, *Denitrification, Carbon
filters. Environmental sanitation, Sanitary engineering, Sewage bacteria.
Water quality, Water pollution sources.
Kinetic equations for biological growth, substrate utilization, and oxygen up-
take with the activated sludge process may be modified and used to describe a
denitrification process. A basic difference between the processes is that the
dependency of variables is interchanged. For denitrification the oxygen
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equivalent from the nitrates is the independent variable and the substrate
supplied is a dependent variable. Coefficients used in the kinetic equations
for denitrification are not well defined as yet but will differ from activated
sludge particularly due to the lower yield characteristics of the denitrifica-
tion process. Experimental data support the validity of the equations as pre-
sented. The rate of nitrate reduction is shown to be a linear function of the
sludge loading rate, and the ratio of substrate applied to nitrate reduced
BOD/N was found to be essentially constant over a wide range of sludge load-
ings. The exact magnitude of the BOD/N ratio is a function of the yield
characteristics of the substrate and the yield characteristics of the biological
treatment system employed. When the substrate or carbon source must be pur-
chased process yields are particularly important.
72-73:05D-010
SUBSURFACE QUALITY TRANSFORMATIONS DURING THE INITIATION OF A NEW STABILIZATION
LAGOON,
Wilson, L. G., Clark, W. I., Ill, and Small G. G.
Arizona University, Water Resources Research Center, Tucson.
Water Resources Bulletin, Vol. 9, No. 2, p 243-257, April, 1973. 3 fig, 3
tab, 15 ref.
Descriptors: *Sewage treatment, *Sewage lagoons, *Seepage, Deep percolation,
Nitrification, Denitrification, Water pollution sources, Leaching, Nitrates,
Chemical oxygen demand, Groundwater.
Raw sewage was metered into a newly-constructed lagoon of the Pima County
Department of Sanitation, Tucson, Arizona. Seepage losses were calculated
from data on inflow, evaporation and change in storage. Water samples were
obtained from shallow suction cups, a 40 foot and a 60 foot PVC well and a
100 foot access tube, all located inside the lagoon. Samples from these
wells, together with water samples from the lagoon, were examined for coliform
organisms and various physical and chemical constituents. Of special concern
were transformations in nitrogen. Estimated seepage rates in the lagoon during
inundation ranged from 0.20 feet per day to 0.10 feet per day. Water level
observations in wells reflected the percolation of effluent to the water table,
70 feet below land surface. Initially, the nitrate ion levels in the suction
cup samples were high, manifesting the leaching of indigenous soil nitrogen.
With the onset of anaerobic conditions at the base of the lagoon, nitrification
was inhibited at the soil surface and ammonia became the predominant form of
nitrogen in the soil solution. Sorption of ammonium ion appeared to occur on
clay particles in a soil zone of high cation exchange capacity. There were no
undesirable microbial or chemical effects of recharge from lagoon seepage on
native groundwater quality.
72-73:050-011
HEAD DROP ACROSS BAR SCREENS,
Yao, K. M.
World Health Organization, West Pakistan.
Journal of the Water Pollution Control Federation, Vol. 44, No. 7, p 1448-1452,
July, 1972. 4 fig, 3 ref.
Descriptors: *Sewage treatment, *Treatment facilities, Screens, Head loss.
Hydraulics.
The head drop across screens used in sewage treatment plants is discussed.
Various equations are presented along with their limitations. Appropriate
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times to use each equation are listed. A nomograph for use by plant operators
is also developed.
72-73:05D-012
NITROGEN REMOVAL BY SOIL MECHANISMS,
Lance, J. C.
United States Water Conservation Laboratory, Phoenix, Arizona.
Journal Water Pollution Control Federation, Vol. 44, No. 7, p 1352-1361, July,
1972. 3 fig, 32 ref.
Descriptors: Nutrient removal, *Nitrogen, Leaching, Denitrification, Sewage
treatment. Solid wastes.
Nitrogen may be removed from a soil system in gaseous form by volatilization of
ammonia or by denitrification. The amount of ammonia volatilized in a land
disposal system is small, but large amounts of nitrogen could be removed during
travel through a long stream or channel to the disposal area. Denitrification
is perhaps the most desirable removal process because large amounts of nitrogen
can be removed and transferred to the atmosphere as nitrogen gas. The nitrogen
is thus completely removed from the system without causing air pollution.
Additional research will be needed to determine whether denitrification can be
sustained in a groundwater recharge system without prior oxidation of ammonium
and/or additional sources of carbon.
72-73:050-013
HAZARDS ASSOCIATED WITH THE USE OF CHLORINATED OXIDATION POND EFFLUENTS FOR
IRRIGATION,
Kott, Y.
Technion - Israel Institute of Technology, Haifa.
Water Research, Vol. 7, p 853-862, 1973. 7 tab, 17 ref.
Descriptors: *Chlorination, Effluents, Hazards, *Irrigation water, *uxidation
lagoons, Water quality control, *Water reuse, Water treatment, *Waste water
treatment.
Identifiers: *Israel.
In Israel more than 200 oxidation ponds are in use, most of them serving rural
communities. It is natural to assume, therefore, that in a country where
about 90 percent of the water resources are utilized, most of the oxidation
pond effluents will be used for irrigation. Reuse of wastewater for agricultur-
al purposes is dependent on health hazards being overcome. Investigations
using 8 miligrams per litre chlorine applied to oxidation pond effluents caused
no algal kill within the first 2 hours of contact. Available chlorine attacks
bacteria, causing coliform count to drop from 100,000 per 100 ml to a few tens.
Enterovirus counts dropped from about 80 per 100 ml to 37 per 100 ml after
chlorination. Vibro cholerai (El-Tor) were killed under these conditions,
and MPN dropped from 1000 per 100 ml in the influent wastes to 2 per 100 ml
in the effluents. A 5 mg per 1 dose of chlorine at 1 h contact time killed
these sensitive bacteria, decreasing MPN to less than 2 per 100 ml. Differences
between the efficiency of chlorination experiments under laboratory and field
conditions would necessitate the application of 15 mg per 1 chlorine for 2 h
of contact. Further study is needed before unrestricted use of oxidation
pond effluents for irrigation purposes is safe unless strict regulations are
issued.
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72-73:050-014
NITROGEN REMOVAL: A LITERATURE REVIEW,
Reeves, T. G.
Kansas State Board of Health, Topeka, Division of Environmental Health.
Journal Water Pollution Control Federation, Vol. 44, No. 10, p 1895-1908,
October 1972. 99 ref.
Descriptors: *Nitrogen, *Nitrogen compounds, *Water pollution treatment, *Water
pollution sources, *Reviews, *Waste water treatment, *Nutrient removal, Ferti-
lizers, Methodology, Microbial degradation, Chemical precipitation. Biological
treatment. Nitrification, Denitrification, Filtration, Distillation, Ion ex-
change, Chlorination, Reverse osmosis, Nitrogen fixing bacteria, Activated
carbon, Activated sludge. Electrochemistry, Pseudomonas, Waste water (Pollution).
Identifiers: Chemical treatment. Air stripping, Nitrosomonas, Nitrosococcus,
Nitrosospura, Nitrosocystis, Nitrosogloes, Achromobacter, Bacillus, Micrococcus.
A literature review is presented on sources of and techniques for the removal
of nitrogen and nitrogen compounds from wastewater. While sources may vary as
widely as domestic wastes to fertilizer, treatment is limited by practicality
and expense. Large scale air stripping cannot yet be considered practical
due to cost and physicochemical problems. Ion exchange may be feasible but
only on a small scale. The most practical available method is biological
nitrification-denitrification involving a 3-stage system which includes a BOD
removal unit, a nitrification (aerobic) unit, and a denitrification (anaerobic)
unit. Other processes, such as electrochemical precipitation, electrodialysis,
reverse osmosis, distillation, breakpoint chlorination, filtering, and slude
techniques are discussed.
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Section XXVI
WATER QUALITY MANAGEMENT AND PROTECTION
ULTIMATE DISPOSAL OF WASTES (Group 05E)
72-73:05E-001
SOIL STORAGE LIMITATIONS ON EFFLUENT IRRIGATION,
Settergren, C. D.
Missouri University, Department of Forestry, Columbia.
Water Resources Bulletin, Vol. 8, No. 6, p 1273-1276, December, 1972. 2 fig,
9 ref.
Descriptors: *Sewage treatment, *Sewage disposal, *Waste water disposal,
Pollution sources, Irrigation.
Over 23 billion gallons of sewage effluent are discharged in the United States
each day. Increasing strict water quality laws make effluent irrigation more
inviting. At an application level of two inches per week, 129 acres are
required to dispose of one million gallons of waste water per day. Dangers
do exist and are delineated. With careful planning and reconnaissance, the
disposal site can be selected to allow for more favorable disposal and renova-
tion potential through irrigation.
72-73:05E-002
AN ECONOMIC ANALYSIS OF SELECTED AGRICULTURAL USES OF WARM WATER IN THE PACIFIC
NORTHWEST RESULTING FROM ELECTRIC POWER GENERATION,
Johns, R. W., Folwell, R. J., Dailey, R. R., and Wirth, M. E.
Washington State University,Department of Agricultural Economics, Pullman.
Journal of Environmental Quality, Vol. 2, No. 2, p 224-228, April-June, 1973.
1 fig, 4 tab, 16 ref.
(See 72-73:053-089)
72-73:05E-003
INJECTION WELLS POSE A POTENTIAL THREAT,
Environmental Science and Technology, Vol. 6, No. 2, p 120-122, February, 1972.
3 fig.
(See 72-73:02F-084)
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Section XXVII
WATER QUALITY MANAGEMENT AND PROTECTION
WATER TREATMENT AND QUALITY ALTERATION (Group 05F)
72-73:05F-001
EVALUATION OF CURRENT TECHNIQUES FOR NUTRIENT REMOVAL FROM WASTEWATERS,
Shindala, A.
Mississippi State University.
Water Resources Bulletin, Vol. 8, No. 5, p 987-998. October, 1972. 32 ref.
(See 72-73:050-005}
72-73:05F-002
ABSORPTION OF MERCURIC CATION BY TANNINS IN AGRICULTURAL RESIDUES,
Waiss, A. C., Jr., Wiley, M. E., Kuhnle, J. A., Potter, A. L., and McCready,
R. M.
United States Department of Agriculture, Berkeley, California.
Journal of Environmental Quality, Vol. 2, No. 3, p 369-371, July-September,
1973. 5 tab, 15 ref.
(See 72-73:050-006)
72-73:05F-003
NITRATE REDUCTION WITH SUBMERGED DRAINS,
Willardson, L. S., Meek, B. D., Dickey, G. L., and Bailey, J. W.
Imperial Valley Conservation Research Center, Brawley, California.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 1,
p 84-90, January-February, 1972. 2 fig, 2 tab.
Descriptors: *Denitrification, *Anaerobic bacteria, *Water pollution sources,
Drainage, Tile drainage. Submergence.
A field experiment has been installed in the San Joaquin Valley of California
to test submergence of drains as a means of denitrification. Laboratory and
field experiments have shown that denitrification occurs in saturated soil
where there is ample organic carbon for bacterial metabolism and a shortage of
oxygen. Denitrification and dilution of high nitrate ground water were accom-
plished in the field.
72-73:05F-004
NITRATE REMOVED AT WATER TREATMENT PLANT,
Gregg, J. C.
Sidney B. Bowne & Son, Mineola, New York.
Civil Engineering, Vol. 43, No. 4, p 45-47, April, 1973. 1 fig.
Descriptors: *Water treatment, Water quality, Water pollution sources. Nitrates,
Ion exchange.
Rising nitrate content in the water supply in Long Island has become a problem,
mainly due to sharply increasing population and the widespread use of septic
tanks and cesspools there. In one water district, it was serious enough to
shut down wells with a potential reduction of 60% in the area's water supply.
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A solution seems to be found by adapting an ion exchange method to remove the
nitrates from the water.
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Section XXVIII
WATER QUALITY MANAGEMENT AND PROTECTION
WATER QUALITY CONTROL (Group 05G)
72-73t05G-001
POTENTIAL FOR CONTROLLING QUALITY OF IRRIGATION RETURN FLOWS,
Law, J. P., Jr., and Skogerboe, G. V.
Robert S. Kerr Water Research Center, Ada, Oklahoma.
Journal of Environmental Quality, Vol. 1, No. 2, p 140-145, April-June, 1972.
1 fig, 23 ref.
Descriptors: *Water quality control, *Irrigation efficiency, *Pollution
abatement, Water conservation. Salinity, Nutrients, Pesticides, Soil erosion,
*Return flow, Sediment transport.
Water quality problems associated with irrigation return flows are difficult
to assess accurately and to control effectively. They include salinity in-
crease, nutrient loss, sediment transport, and pesticide residue. The effects
of these on the quality of receiving waters are discussed. Potential control
measures that may prove effective in alleviating the detrimental effects of
irrigation return flows are suggested. These may involve physical changes in
the system, improvements in present management and cultural practices, or
changes in the institutional influences upon the system. The potentials for
improving the quality of return flows through changes in the water delivery
system, farm water management practices, and water removal system are outlined
and discussed. Research investigations will be required to further evaluate
the effectiveness of many of the controls suggested.
72-73:056-002
A MULTILEVEL APPROACH TO DETERMINING OPTIMAL TAXATION FOR THE ABATEMENT OF WATER
POLLUTION,
Haimes, Y. Y., Kaplan, M. A., and Husar, M. A., Jr.
Case Western Reserve University, Cleveland, Ohio, Systems Engineering Division.
Water Resources Research, Vol. 8, No. 4, p 851-860, August 1972. 3 fig, 4 tab,
16 ref.
Descriptors: *Water quality control, *Pollution abatement, *Pollution taxes
(Charges), *River basins, Optimization, Waste water treatment, Costs, Digital
computers, Simulation analysis, Biochemical oxygen demand, Mathematical models,
Systems analysis, Dissolved oxygen.
Identifiers: *Regional water quality management, *Miami River basin, Cost
functions, Plant capacity, Treatment level, Polluters.
A three-level optimization approach is developed for regional water quality
management. The problem of simultaneously finding an optimal waste water treat-
ment configuration for meeting water quality standards along a river basin and
determining optimal effluent charges to achieve this configuration is solved
by decomposition and the multilevel approach. The optimal regional plant
capacity and the regional treatment level are also found, depending on which
polluters decide to use the regional facilities. (1) The individual polluters,
(2) the regional treatment plant, and (3) the central authority are the three
levels of optimization that are introduced for solution of the regional problem.
It is assumed that the central authority does not need to know the local cost
functions. Numerical results from simulated use of the technique with data for
the Miami River basin reveal the efficiency and the effectiveness of the multi-
level, hierarchical approach in the modeling, control, and management of
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regional water quality problems. Considerable savings over local treatment
alone can be realized by employing regional treatment facilities.
72-73:050-003
SALINITY AND SEDIMENTATION STUDY - COOPER RIVER REDIVERSION, CHARLESTON, SOUTH
CAROLINA,
Jacobs, M. L.
Ellers, Reaves, Fanning and Oakley, Incorporated, Memphis, Tennessee.
Water Resources Bulletin, Vol. 8, No. 1, p 87-92, February 1972. 4 ref.
Descriptors: *Saline water intrusion, *Sedimentation, *Harbors, *Canals,
*Reservoirs, Hydroelectric power, Hydraulics, Discharge (Water), Salinity,
Wetlands, Water quality, Surveys.
Identifiers: Charleston Harbor (SC) .
Lakes Marion and Moultrie are located north of Charleston, S.C. on the Santee
and Cooper Rivers, respectively. The impounded waters of both are utilized
in the operation of generating plants and discharge into the Cooper River,
the principal freshwater component of the Charleston Harbor.
Excessive sedimentation and pollution problems in the Charleston Harbor led
to consideration of several rediversion plans. This study applies to diversion
of the flow of the Cooper River through an artificial channel which would
cross the saltwater marsh area between dykes and discharge into the Atlantic
Ocean at right angles to the coast between jetties. Salinity will be signifi-
cantly reduced in the areas on both sides of the rediversion channel. Signi-
ficant sedimentation will occur in the areas on both sides of the rediversion
channel. SEDIMENTATION DERIVED FROM THE SEAWARD DISCHARGE FROM THE DIVER-
SION JETTY SYSTEM WILL BE INSIGNIFICANT IN THE COASTAL MARSH AREAS NE of the
rediversion channel and will be generally unimportant in the first decade or
two of the life of the project SW of the channel. If the rediversion is to be
seriously considered, the possibility of providing a barrier to density exchange
should be investigated. In any case, a model study should be undertaken to
establish quantitative values for consideration of those interested in the
project.
72-73:056-004
MATHEMATICAL PROGRAMMING FOR REGIONAL WATER QUALITY MANAGEMENT,
Graves, G. W., Hatfield, G. B., and Whinston, A. B.
California University, Los Angelos, School of Business.
Water Resources Research, Vol. 8, No. 2, p 273-290, April 1972. 13 fig, 12 tab,
5 ref.
Descriptors: *Estuary, *Water quality control, Delaware River Basin Commission,
Optimization, Systems analysis, *Mathematical models, Water temperature.
Biochemical oxygen demand, Dissolved oxygen. Flow, Linear programming, Model
studies, *Regional analysis.
Identifiers: *Delaware Estuary, *Regional treatment systems. By-pass piping.
A mathematical model was developed to define minimum cost water quality control
policies in the Delaware Estuary. Control alternatives included treatment
at the waste source and by-pass piping with regional treatment. The model
was solved using both linear and non-linear programming algorithms. A small-
scale problem with five dischargers, three estuary sections, and three potential
treatment plants was set up to illustrate the methodology used. The results
indicated that a regional treatment system for the Delaware Estuary is less
costly than other proposed schemes.
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72-73:056-005
PROGRESSIVE TAXATION AS A POLICY FOR WATER QUALITY MANAGEMENT,
Ferrar, T. A.
California University, Riverside, Department of Economics.
Water Resources Research, Vol. 9, No. 3, p 563-568, June 1973. 3 fig, 5 ref.
Descriptors: *Water resources, *Water quality, *Management, *Pollution taxes
(Charges), *Water quality standards. Effluents, Pricing, Waste disposal,
Resource allocation. Mathematical models, Systems analysis, Optimization.
Identifiers: *Cost minimization.
Recent literature on environmental control and water resources management has
advocated the allocative efficiency associated with standard effluent taxation
control measures. This article demonstrates that the operational characteris-
tics of such techniques tend to render them impotent as standard maintenance
measures. The significant operational weakness is a fundamentally static
applicability. Since most acute environmental problems occur in vigorously
developing metropolitan areas, the concept of a linear, static equilibrium
charge is meaningless in such dynamic settings. A new, nonlinear effluent
taxation structure is proposed that alleviates this weakness by incorporating
a progressive taxation schedule that is tied to water quality standards. An
allocation model is outlined, and the rationing procedure involves an incentive-
feedback algorithm that iteratively allocates the available environmental
resource among the polluters in accordance with a cost minimization objective.
72-73:05G-006
SEDIMENT CONTROL,
Bowen, D. K.
Soil Conservation Service, Washington, D. C.
Agricultural Engineering, Vol. 53, No. 7, p 17-19, July 1972.
Descriptors: *Sedimentation, *Sediment control, *Sediment discharge, *Maryland,
*Regulation, Water pollution control, Water pollution sources.
Identifiers: Maryland Department of Natural Resources
The state of Maryland's decision processes and resultant laws concerning sedi-
ment control stemmed from the recognition that uncontrolled erosion is a
hydraulic pollutant. Due to suburbanization, the Potomac River and Sligo Creek
were altered by the sediment discharges from land clearing operations. Regula-
tions to control sediment were developed and administered at the local level,
with state 'oversight1 providing uniformity between counties and comparable
regulation for state agencies. County soil conservation districts handle the
bulk of administration and enforcement, while the Maryland Department of
Natural Resources handles the coordinating, regulating, and approval functions
on a statewide level. The process and scope of Maryland's solution to sedi-
ment control is of value to any agency, county, or state devising such controls.
72-73:050-007
MOVEMENT OF NITRATES UNDER IRRIGATED AGRICULTURE,
Edwards, D. M., Fischbach, P. E., and Young, L. L.
Nebraska University, Lincoln.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 1,
p 73-75, January-February, 1972. 6 fig, 14 ref.
(See 72-73:05B-034)
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72-73:05G-008
CHEMICAL AND BIOCHEMICAL CONSIDERATIONS FOR MAXIMIZING THE EFFICIENCY OF FERTI-
LIZER NITROGEN,
Parr, J. F.
United States Department of Agriculture, Baton Rouge, Louisiana.
Journal of Environmental Quality, Vol. 2, No. 1, p 75-84, January-March, 1973.
6 fig, 2 tab, 56 ref.
(See 72-73:05B-046)
72-73:05G-009
NITROGEN-15 ENRICHMENT OF SOILS AND SOIL-DERIVED NITRATE,
Bremner, J. M., and Tabatabai, M. A.
Iowa State University, Ames.
Journal of Environmental Quality, Vol. 2, No. 3, p 363-365, July-September,
1973. 3 tab, 12 ref.
(See 72-73:05B-053)
72-73:050-010
NITROGEN TRANSFORMATIONS IN SEDIMENTS AS AFFECTED BY CHEMICAL AMENDMENTS,
Chen, R. L., and Keeney, D. R.
Wisconsin University, Madison.
Water Resources Bulletin, Vol. 9, No. 6, p 1136-1144, December, 1973. 8 tab,
27 ref.
(See 72-73:02H-001)
72-73:05G-011
ESTIMATION THEORY APPLICATIONS TO DESIGN OF WATER QUALITY MONITORING SYSTEMS,
Moore, S. F.
Massachusetts Institute of Technology, Cambridge, Department of Civil Engineer-
ing.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
99, No. HY5, Proceedings paper No. 9755, p 815-831, May 1973. 8 fig, 6 tab,
9 equ, 12 ref.
Descriptors: *Water quality control, *Monitoring, *Stochastic processes,
*Data collections, *Estimating, Hydraulics, Water quality standards. Economics,
Optimization, Costs, Management, Mathematical models, *Design, Systems analysis,
Equations, Aquatic environment.
Identifiers: *Data systems. Filtering techniques.
The objectives of water quality control are quantified in water quality stand-
ards, and enforcement of standards is the feedback mechanism for quality con-
trol. To achieve effective control, engineers need a knowledge of the state
of the aquatic ecosystem. The necessary information is obtained from monitoring
or data collection programs and an understanding of the phenomena involved
(a model). A quantitative methodology, utilizing Kalman filtering techniques,
is developed for designing water quality monitoring systems. A basis is
established for: (1) Improvement of current practices of specification and
enforcement of water quality standards; and (2) evaluating the economic trade-
off between temporal and spatial frequency of sampling. Monitoring systems are
characterized by spatial and temporal frequency of sampling and the variables
to be measured. Utilizing a dynamic model of the aquatic environment and
estimates of the uncertainty in model error and measurement error, a best
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sampling program is selected from a set of feasible sampling programs by
sequentially minimizing a specified measurement system cost function. An
optimal solution is not guaranteed. The power of the technique is based on the
unique combination of model and data obtained from filtering techniques. The
major shortcomings are: (1) the need for a model of the systems and (2) high
computer costs.
72-73:050-012
COMPUTATIONAL RESULTS FOR WATER POLLUTION TAXATION USING MULTILEVEL APPROACH,
Haimes, Y. Y., Foley, J., and Yu, W.
Case Western Reserve University, Cleveland, Ohio, Systems Research Center.
Water Resources Bulletin, American Water Resources Association, Vol. 8, No. 4,
p 761, 772, August 1972. 3 fig, 2 tab, 13 ref.
Descriptors: *Pollution taxes (Charges), Waste treatment, Waste water treat-
ment, *Cost analysis, *Water quality control, *Water pollution control, Bio-
chemical oxygen demand. Model studies, Mathematical models, Optimization,
Theoretical analysis, Water pollution sources.
Identifiers: Multilevel mathematical approach.
A regional authority was postulated as a pollution abatement agency with the
task of minimizing the total cost of waste treatment to the region. Data from
the Miami River in Ohio are used to model a 27 reach river with 15 BOD dis-
chargers. The multilevel approach with a 2 level optimization hierarchy is
applied to the river system. At the first level each subsystem is independently
optimized, and at the second level the subsystems solutions are coordinated to
yield an overall optimum to the whole region. The initial level approach
assumes a knowledge of the local treatment cost functions by the regional
authority while the other approach assumes no such knowledge. Computational
results are presented to complement the theoretical discussions on the multi-
level approach.
72-73:056-013
SELECTED IRRIGATION RETURN FLOW QUALITY ABSTRACTS 1970-1971, SECOND ANNUAL
ISSUE,
Skogerboe, G. V., Walker, W. R., Meyer, D. J., and Bennett, R. S.
Colorado State University, Fort Collins, Department of Agricultural Engineering.
Environmental Protection Agency, Technology Series Report, EPA-R2-73-271,
June 1973. 285 p.
Descriptors: *Fertilizers, Irrigated land, Irrigation systems, *Irrigation water,
*Nitrates, *Phosphates, *Return flow, Salinity, Water pollution effects, Water
pollution sources, Water quality control, Abstracts, *Bibliographies.
Research related to the quality of irrigation return flow is being conducted
at numerous institutions throughout the western United States. Related work
is also underway at other institutions in the United States, as well as other
portions of the world. Approximately 100 sources of material have been searched
for articles pertinent to the National Irrigation Return Flow Research and
Development Program. These articles describe water quality problems resulting
from irrigated agriculture, potential technological solutions for controlling
return flows, recent research pertinent to return flow investigations, and
literature associated with institutional constraints in irrigation return
flow quality control. This second annual issue of SELECTED IRRIGATION RETURN
FLOW QUALITY ABSTRACTS contains approximately 450 abstracts of documents
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published in 1970 and 1971. Author and subject indexes are included.
72-73:050-014
NUTRIENT BALANCE FOR THE EVALUATION OF NUTRIENT SOURCES IN WATER QUALITY
MANAGEMENT,
Peters, R. H.
Department of the Environment, Water Quality Branch, Ottawa, Canada.
Water Resources Bulletin, Vol. 9, No. 1, p 49-53, February, 1973. 2 fig, 3 tab,
1 ref.
(See 72-73:056-087)
72-73:050-015
PREDICTION MODELING FOR SALINITY CONTROL IN IRRIGATION RETURN FLQWS,
Hornsby, A. G.
Robert s. Kerr Environmental Research Laboratory, Ada, Oklahoma.
Environmental Protection Technology Series Report EPA-R2-73-168, March 1973.
55 p, 6 fig, 101 ref.
Descriptors: *Irrigation systems, Surface flow, Subsurface flow, Salt movement,
Ion exchange. System analysis, Water resources, Management, Evapotranspiration,
Soil physical properties, Soil moisture, *Reviews, *Return flow, *Salinity,
Model studies, *Water management (Applied).
A review of the current state-of-the-art of prediction modeling as applied to
salinity control in irrigation return flows is presented. Prediction models
are needed to assess the effects of proposed changes in irrigation management
practices on the quality of return flows. The processes which affect salinity
levels in return flows are enumerated and their interactions are alluded to.
Models used to predict the quantity and quality of return flows are briefly
discussed to show the development of the current level of technology. The
readers are referred to the original documents for more rigid development of
the models and incumbent assumptions. It was concluded that technology of
water and salt flow in soil systems is sufficiently developed to permit formula-
tion of models using systems analysis to evaluate proposed changes in manage-
ment practices. Development of systems models to study irrigation return flow
problems.and conjunctive water resource uses was recommended.
72-73:050-016
IRRIGATION MANAGEMENT FOR CONTROL OF QUALITY OF IRRIGATION RETURN FLOW,
King, L. G., and Hanks, R. J.
Utah State University, Logan, Department of Agricultural and Irrigation Engi-
neering.
Environmental Protection Agency, Technology Series Report EPA-R2-73-265, June
1973. 307 p, 81 fig, 60 tab, 75 ref.
Descriptors: *Return flow, *Leaching, *Salinity, Irrigation practices, Colo-
rado River Basin, Environmental effects, Water quality, Irrigation, Drainage,
Soil water, Management, Drainage effects, Computer models, *Model studies,
*Utah.
Identifiers: Return flow quality, On-farm water management, Salt storage.
Irrigation scheduling, Salt movement, Irrigation frequency, Irrigation manage-
ment. Field irrigation studies, Ashley Valley (xitah).
312
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Field studies tested the possibilities for using the unsaturated soil profile
including the crop root zone as a temporary salt reservoir and providing excess
water for leaching and salt discharge when desired. Two models were developed
for describing flow of water and salt through the soil with extraction of
water by evapotranspiration. One model was designed for use as an irrigation
management tool while the other model was initially intended to provide a
detailed understanding of the water and salt flow through i-.he soil. The best
management model will probably result from a combination of the two models
described. Timing of irrigation was tested as a management variable. With
all other conditions the same, the model predicts that as the time interval
between irrigations increases, the season totals of salt removed from the
root zone, salt remaining in the profile, and water required for leaching tend
to level off. However, the irrigation frequency has a significant effect
upon when the salt is discharged during the season. Results indicate that
managing irrigation for control of return flow quality requires good control of
depth and timing of irrigation. Some needs for further research are given.
313
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Section XXIX
WATER RESOURCES PLANNING
TECHNIQUES OP PLANNING (Group 06A)
72-73:06A-001
ALGEBRAIC TECHNOLOGICAL FUNCTION FROM A SIMULATION MODEL,
Maddock, T., Ill
Harvard University, Cambridge, Massachusetts
Water Resources Research, Vol. 8, No. 1, p 129-134, February 1972. 2 fig,
2 tab, 8 ref.
Descriptors: *Simulation analysis, *Systems analysis, *Optimization, *Econom-
ics, *Water costs, Cost-benefit analysis. Water management (Applied), Irrigation
water, Parametric hydrology. Mathematical models.
Distributed-parameter models for groundwater simulation are difficult to
couple explicitly with management models that seek to optimize an economic
objective. For a groundwater system whose drawdown in response to pumping was
modeled by a two-dimensional linear partial differential equation, an algebraic
technological function was produced that related seasonal pumping at wells in
the system to drawdown at those wells. The algebraic technological function
allows explicit coupling of the groundwater model with a quadratic programming
management model.
72-73:06A-002
DYNAMIC MULTISECTOR PROGRAMMING APPROACH TO REGIONAL WATER RESOURCE MANAGEMENT,
Bargur, J.
Tahal Consulting Engineers Limited, Tel-Aviv (Israel), Research and Development
Division.
Water Resources Research, Vol. 8, No. 4, p 801-817, August 1972. 3 fig, 5
tab, 15 ref.
Descriptors: *Water management (Applied), *Planning, "Regional analysis,
Water resources, Resource allocation. Optimization, Linear programming, *Cali-
fornia, Systems analysis. Model studies.
Identifiers: Equilibrium analysis.
In arid and semiarid areas, water is scarce and requires an intersectoral,
intertemporal, and sometimes interregional planning approach to insure its
efficient use and allocation among the competing factors. In most cases, the
water scarcity is an economic phenomenon that is partially determined by the
costs of undertaking water development and water transfer projects. Presented
is a multisector planning and management approach to water resources that is
based on a general equilibrium analysis using input-output models and linear
programming techniques. A dynamic multisector programming model that takes
into account the sectoral, spatial, and temporal aspects of regional planning
and an extension to an activity analysis model are formulated and applied
empirically to California and the western United States for a 15-year planning
horizon. Results include water requirement forecasts, interregional water
transfer requirements, efficient production and cropping patterns, 'shadow
prices' for water and labor, and an optimal investment program for water re-
source projects. Using a general equilibrium programming model makes it poss-
ible to investigate problems of regional development that are dependent on the
interrelationships between resource availabilities and sectoral planning and
illustrates the importance of the complex interdependencies among economic
variables.
314
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72-73:06A-003
COMBINED USE OF OPTIMIZATION AND SIMULATION MODELS IN RIVER BASIN PLANNING,
Jacoby, H. D., and Loucks, D. P.
John F. Kennedy School of Government, Cambridge, Massachusetts.
Water Resources Research, Vol. 8, No. 6, p 1401-1414, December, 1972. 3 fig,
27 equ, 15 ref.
Descriptors: *Optimization, *Simulation analysis, *River basins, *Planning,
*Computer programs, *Delaware River, Digital computers. Alternative planning,
Mathematical models, Systems analysis.
Simulation models have proved to be extremely useful in aiding river basin
planning. However, all suffer a common difficulty, since the analyst himself
must formulate the physical design to be studied in each computer run. If
the basin is large and offers a variety of development opportunities, the
number of alternative system plans from which he must choose can be extremely
large. An investigation is reported of the use of analytical optimization
models to 'screen1 the set of possible plans and to select a small number worthy
of simulation analysis. Deterministic and stochastic optimization models have
been developed and applied to both static and dynamic (multi-period) planning
problems; the Delaware River basin is used as an example. The resulting designs
have been analyzed by using a large-scale digital simulation model of the basin
so that the ability of the screening models to identify high-valued alternatives
can be evaluated. In this context the results indicate considerable promise
for the combined use of optimization and simulation models.
72-73:06A-004
IMPROVED RIVER BASIN UTILIZATION THROUGH SYSTEMS ANALYSIS,
Foster, E. T., Jr., Chen, T. C., Newton, J. P., and Isu, E. O.
HDR Systems, Omaha, Nebraska.
Water Resources Bulletin, American Water Resources Association, Vol. 8, No. 5,
p 863-870, October, 1972. 2 fig, 3 tab, 18 equa, 14 ref.
Descriptors: *Water distribution (Policy), *River basins, Management, Opera-
tions, Facilities, Optimization, *Linear programming, *Montana, *Missouri
River basin, *Decision making. Systems analysis, Mathematical models, Reservoirs,
Diversion structures, Dams, Constraints, Equations.
Identifiers: Objective functions, *Marias River basin, *Milk River basin.
Theoretical and practical results are examined for a study to determine optimal
water resource allocation in the 30,000-square-mile Montana North Central
Conservancy District. The district covers several river basins and contains
numerous existing and proposed facilities (dams, reservoirs, and diversion
canals). The study determined the operation of all these facilities along with
the sizing of the proposed facilities in order to optimize given objective
functions. Related efforts in optimal river basin utilization were surveyed,
and linear programming was selected as an expedient optimization technique.
Herein, the problem is formulated by identifying time stages which together
constitute a repetitive cycle such as a year. With these stages, it is poss-
ible to associate operational and capacity variables with network components,
which are branches or nodes. Objective functions are assembled for the compo-
nent variables. Constraint equations are written in terms of the variables
to reflect network nodal continuity, capacity restrictions, and adjudications
such as water rights. A numerical example is considered in which the existing
and proposed facilities are aggregated to produce a small, tractable number of
facilities. Linear programming is shown to be quite feasible as a decision
making technique for optimum water resource utilization.
315
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72-73:06A-005
WATER PRODUCTION FUNCTIONS AND IRRIGATION PROGRAMMING FOR GREATER ECONOMY IN
PROJECT AND IRRIGATION SYSTEMS DESIGN AND FOR INCREASED EFFICIENCY IN WATER USE,
Stewart, J. I., Hagen, R. M., Pruitt, W. D., and Hall, W. A.
California University, Department of Water Science and Engineering, Riverside.
Report No. 14-06-D-7329, United States Bureau of Reclamation, Denver, Colorado,
March 1973. 165 p, 21 fig, 15 tab, 3 append.
Descriptors: *Water utilization, Irrigation, Water management (applied).
Water requirements, Evapotranspiration, Economic feasibility.
A continuing long term study aimed at quantitative prediction of relations
between yields of principal crops and water is reported. Results of four years
of field experiments on corn and two years on grain sorghum are included, along
with conceptualization and detailed methodology of a comprehensive approach
to planning the use of water in agriculture. The method combines researched
genetic characteristics of crops with planned irrigation site measurements of
climate, soil and irrigation capabilities to estimate quantitatively:
(1) Generalized relative value functional relations between yield and evapo-
transpiration of given crop varieties.
(2) Generalized absolute value yield vs. evapotranspiration functions for
given crop varieties in measured evaporative conditions.
(3) Absolute value yield vs. Irrigation (season depth) functions for given
crop varieties in measured conditions of climate, soil, and irrigation
capability.
(4) Optimal programs of dates and depths of irrigation suited to given crop
varieties in measured environments.
316
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Section XXX
WATER RESOURCES PLANNING
EVALUATION PROCESS (Group 06B)
72-73:06B-001
LEARNING, EXTERNAL BENEFITS, AND SUBSIDES IN WATER DESALINATION,
Rausser, G. C., Willis, C., and Prick, P.
California University, Davis, Department of Agricultural Economics.
Water Resources Research, Vol. 8, No. 6, p 1385-1400, December, 1972. 1 fig,
7 tab, 12 equ, 2 append, 33 ref.
Descriptors: Water resources, *Desalination, *Investment, *Decision making,
*Costs, Estimating, Sea water, *Simulation analysis, Computers, Mathematical
models, Systems analysis.
Identifiers: Learning, *External benefits, ^Subsidies, Bayesian methods,
Distillation plants.
In the absence of the recognition of learning in new technologies such as
desalting, water resources investment decisions may be erroneous for two
reasons. First, neglecting cost reductions over time due to 'learning by doing1
leads to the overestimation of costs. Second, since learning in a particular
desalting plant may result in external learning benefits to other plants, these
externalities may serve as the basis for the determination of a subsidy intended
to internalize these benefits. Estimates, of learning (cost) functions for
largescale seawater distillation plants are provided. To incorporate prior
information into the estimation process, Bayesian methods are used. Alternative
specifications of these learning functions are then employed in the context
of a measure of external learning benefits to estimate by computer simulation
the moments of these benefits. The employing of such a measure in various
water resource decision models is discussed. It is obvious that the estimates
of external learning benefits provided can be introduced into investment-
sequencing models that seek to optimize the sequencing and timing of a number
of alternative projects.
72-73:06B-002
A SIMULATED ENVIRONMENTAL MODEL OF TEMPERATURE, EVAPORATION, RAINFALL, AND SOIL
MOISTURE,
Jones, J. W., Colwick, R. F., and Threadgill, E. D.
United States Department of Agriculture, State College, Mississippi.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 5,
p 366-372, March-April, 1972. 8 fig, 2 tab, 24 ref.
(See 72-73:02A-006)
317
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Section XXXI
WATER RESOURCES PLANNING
WATER DEMAND (Group 06D)
72-73:060-001
INTEGRATION OF THE AGRICULTURAL DEMAND FUNCTION FOR WATER AND THE HYDROLOGIC
MODEL OF THE PECOS BASIN,
Gisser, M., and Mercado, A.
New Mexico University, Albuquerque, Department of Economics.
Water Resources Research, Vol. 8, No. 6, p 1373-1384, December, 1972. 1 fig,
7 tab, 2 append, 8 ref.
Descriptors: Economics, *Parametric hydrology, Agriculture, *Water demand,
*Imported water, *Costs, *Estimating, *Linear programming, *Artificial recharge,
*New Mexico, Systems analysis, Mathematical models, Pumping, Water table,
Discharge (Water), Irrigation, Confined water, Shallow water. Equations, Fore-
casting.
Identifiers: *Pecos River basin, *Demand function, Roswell basin, San Andres
aquifer.
The result of integrating the agricultural sector with the aquifer of the
Pecos basin is presented. In particular, steady state solutions to hydrologic
and economic equations are given in which imported water is artificially
recharged to the aquifer and its cost is combined with the cost of pumping.
A two-cell model (consisting of five equations) for the Pecos basin aquifer is
developed, which yields optimal steady state solutions for a variety of prices
of imported water. One cell is for the confined aquifer and the other is for
the shallow aquifer. The hydrologic solution of the model yields two linear
steady state functions that relate the water table in the two cells to other
hydrologic variables, such as recharge, discharge, and irrigation. The cost
of pumping water is also estimated. The agricultural demand function for
irrigation water is empirically estimated by applying parametric linear pro-
gramming. The demand function for water is linked to the water table hydrolo-
gic equations. Solutions are found for a range of expected prices of imported
water. Two basic assumptions underlie this study: 1) Imported water will be
artificially recharged into the ground; and 2) farmers will pay the full price
of imported water.
72-73:060-002
NATIONAL AND INTERREGIONAL MODELS OF WATER DEMAND, LAND USE, AND AGRICULTURAL
POLICIES,
Heady, E. O., Madsen, H. C., Nicol, K. S., and Hargrove, S. H.
Iowa State University, Ames, Department of Economics.
Water Resources Research, Vol. 9, No. 4, p 777-791, August 1973. 10 fig,
2 tab, 11 ref.
Descriptors: *Mathematical models, *Water demand, United States, *Land use,
*Agriculture, *Resource allocation, *Water supply, *Pricing, Marketing, Irri-
gation water, Regions, Human population. Crops, Foods, Fiber crops. Reservoirs,
Economics, Equations, Systems analysis. Optimization, Planning.
Identifiers: Interregional analysis, Cost minimization.
A study is presented of the optimum allocation of land and water resources in
223 agricultural land regions, 51 water supply regions, and 27 market regions
of the United States. The study is built upon a family of programming models
318
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which incorporate all major U.S. agricultural commodities into a supply-
demand and resource use interaction, and endeavors primarily to determine wheth-
er or under what conditions the nation has enough water to produce its future
food and fiber requirements under urban and industrial water demands reflected
in various levels and distributions of population and national economic activity
in the year 2000. The amount of water used in agriculture is partly a function
of the prices of water for irrigation; hence an auxiliary objective is to
formulate models to reflect (normatively) the demand for water under different
pricing policies. Analyzed are the impacts of future alternatives on the demand
for water, such as water prices, population levels, farming technology,
export quantities, and agricultural policies. In general, results show that,
if agricultural and water development policies were changed over the future,
the nation would not be faced with an overall water scarcity, and even surplus
food producing capacity could exist with the use of less water for agricultural
purposes.
72-73:06D-003
LAND USE TRENDS AND THE FUTURE OF AGRICULTURE IN THE NORTH ATLANTIC REGION,
Zube, E. H.
Massachusetts University, Department of Landscape Architecture and Regional
Planning, Amherst.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 2,
p 232-234, 238, March-April, 1972. 10 ref.
Descriptors: *Land use. Land management, Land development, Rural areas.
Urbanization, Zoning.
A literature review study showing that agricultural and open land will decrease
by as much as 50% by the year 2020 if present trends continue. An argument
for keeping pure land is also presented.
319
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Section XXXII
WATER RESOURCES PLANNING
WATER LAW AND INSTITUTIONS (Group 06E)
72-73:06E-001
GENERAL STATEMENT OF PRINCIPLES TO BE INCLUDED IN STATE WATER RIGHTS LAWS.
American Society of Civil Engineers, New York, Committee on Water Laws.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR2, p 317-322, June 1972.
Descriptors: *Water rights, *Appropriation, ^Adjudication procedure, State
jurisdiction, Groundwater, Water quality. Controlled drainage, Prior appropria-
tion.
This is a consensus report that has been in preparation since March, 1965. Its
primary purpose is to allow and encourage others to enter in formalized Dis-
cussion. After the Discussion is closed the Committee will consider all
suggestions before preparing a final statement. Items covered include policy
objectives, vested rights, fundamental principles of priority, water filings,
appropriation limited to specific quantity, completion of work, proof of
beneficial use, adjudication, forfeiture, change in point of diversion, eminent
domain, groundwater, water quality, drainage requirements, safety of structures,
administration and interstate water resources. The principle of priority
should be followed in all circumstances, limitations should be placed on the
use of water in exercising basic rights and time limits should be set for
beneficial use. Other main points made are that groundwater appropriation
should follow the same general principles as surface water, states should set
quality standards and interstate water resources should be governed by inter-
state compacts.
72-73:06E-002
STATE WATER RIGHTS LAWS,
Walker, W. R.
Virginia Polytechnic Institute and State University, Blacksburg.
Preprint No. 1908, American Society of Civil Engineers, National Water Resources
Engineering Meeting, Washington, D.C., January 29-Pebruary 2, 1973. 12 p.
Descriptors: *Water rights, *Water allocation, *Prior appropriation, *Water
law, Competing uses, Appropriation, Beneficial use, Legal aspects.
Identifiers: *Committee on Water Laws (ASCE).
The Committee on Water Laws of the Irrigation and Drainage Division of the
American Society of Civil Engineers has suggested that states declare a water
use policy. The Committee has developed a general statement for a recommended
policy for adoption by the states. This policy declares that all water in
its natural environment is part of the public wealth and that it is a natural
resource subject to appropriation. Implicit in this statement is the declara-
tion that the appropriation doctrine, as applied in the western United States,
should be adopted by all states. This doctrine recognizes three distinct
elementsdiversion, reasonable beneficial use, and private property. This
publication questions the desirability of accepting western water right
appropriation doctrines universally and, to some extent, the desirability of the
continued application of this doctrine in the West. For example, under present
appropriation laws, the use of water for maintaining low streamflows to
320
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protect fish life and provide recreation was found not to be a valid appropria-
tion because an actual diversion was not necessary. Many other problems
exist in deciding the best possible beneficial use of desired diversions and
in the length of time the appropriations are granted.
72-73:06E-003
INTERSTATE AND INTERNATIONAL AQUIFERS,
Bittinger, M. W. , and Jones, E. B.
M. W. Bittinger and Associates, Incorporated, Fort Collins, Colorado.
Water Resources Bulletin, Vol. 8, No. 2, p 386-390, April, 1972. 11 ref.
Descriptors: *Groundwater, *Aquifers, Interstate, International waters, Water
law, Water utilization.
Many important groundwater aquifers cross state and national boundaries. The
flow of water in these aquifers is not influenced by the boundaries but may be
materially influenced by man's activities on one or both sides of a boundary.
Interstate and international problems may develop because of excessive ground-
water lowering on one side of a boundary affecting water users on the opposite
side of the line. Similarly, intensive groundwater development along a surface
stream may influence the amount of surface water that flows across a boundary.
A third type of problem may develop when pumping on one side of the boundary
induces poor quality water into an aquifer on the other side of the boundary.
Several specific interstate and international aquifer problems are briefly
described.
72-73:06E-004
INSTITUTIONAL CONSTRAINTS ON AGRICULTURAL WATER USE,
Ward, R. C., Skogerboe, G. V., and Walker, W. R.
Colorado State University, Agricultural Engineering Department, Fort Collins,
Colorado.
Presented at Winter Meetings of the American Society of Agricultural Engineers,
December 11-14, 1973. Chicago, Illinois. 18 p, 18 ref.
Descriptors: *Water utilization, *Agriculture, Institutional constraints,
Law enforcement.
Scarcity of water in the western United States has resulted in the development
of a vast institutional framework to insure its just allocation. The institu-
tions are briefly reviewed, and their impact on agriculture's water use is
discussed.
72-73:06E-005
WATER LAW AND THE HYDROLOGIC CYCLE: A TEXAS EXAMPLE,
Templer, O. W.
Texas Tech University, Department of Geography, Lubbock.
Water Resources Bulletin, Vol. 9, No. 2, p 273-283, April, 1973. 2 fig, 39 ref.
Descriptors: *Water law, *Legislation, *Texas, Riparian rights, Groundwater,
Hydrologic cycle. Water rights, Water utilization, Water wells, Water yield.
The law divides water in the cycle into several different classes. Each is
treated separately and generally without consideration of interconnections
321
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existing within the cycle. Different rules of law have arisen concerning the
ownership and use of each legal class. Under Texas law several classes of
surface and ground water are recognized, and weather modification efforts
bring yet another class, atmospheric moisture, under consideration. It is
instructive to follow water moving through the hydrologic cycle in the Nueces
River basin, Texas, as a framework for discussing the substantial interconnec-
tions between the various legal classes of water and the difficulties that
arise from attempts to apply different rules of law to each class. Strictures
imposed by Texas water law can seriously interfer with coordinated, efficient
use and management of water resources, as evidenced by the Nueces River basin.
Well-recognized, existing water rights in the several phases of the hydrologic
cycle make change of these institutional constraints difficult to achieve.
322
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Section XXXIII
WATER RESOURCES PLANNING
ECOLOGIC IMPACT OF WATER DEVELOPMENT (Group 06G)
72-73:06G-001
SOIL AND WATER CONSERVATION RESEARCH: CHALLENGE FOR THE 70'S,
van Schilfgaarde, J.
United States Department of Agriculture, Agricultural Research Service, Belts-
ville, Maryland.
Agricultural Engineering, Vol. 54, No. 4, p 17, 20, April, 1972.
Descriptors: ^Conservation, Soil conservation, Water conservation, Research
priorities.
Article consists of a talk presented by the author concerning the research
needed in agriculture during the 1970's. Figures of work already done present-
ed and an outline of needed research is made.
323
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Section XXXIV
RESOURCES DATA
DATA ACQUISITION (Group 07B)
72-73:07B-001
AUTOMATIC SAMPLER FOR DYE TRACER STUDIES,
Kilpatrick, F. A.
Geological Survey, Washington, D.C., Water Resources Division
Water Resources Research, Vol. 8, No. 2, p 737-742, June 1972. 4 fig, 7 ref.
Descriptors: *Sampling, *Dye releases, *Tracers, Tracking techniques, Dye
dispersion. Dye concentrations. Automation.
A simple, largely mechanical device for automatically collecting periodic
discrete water samples for use in dye tracer studies has been developed and
successfully used by the U.S. Geological Survey. The device consists essenti-
ally of two rows of spring-loaded hypodermic syringes that are released from
their closed position at selected time intervals to draw in and retain the
desired water samples. The sampler is mounted in a boatlike structure parti-
ally immersed in the flow to be sampled.
72-73:07B-002
SOIL SURFACE WATER DEPLETION AND LEAF TEMPERATURE,
Aston, A. R., and Van Bavel, C. H. M.
Texas A and M University, College Station, Remote Sensing Center.
Agronomy Journal, Vol. 64, p 368-373, May-June 1972. 7 fig, 7 ref.
Descriptors: *Soil temperature, *Surface waters, *Environmental effects,
*Drying, *Soil environment, *Thermal radiation. Leaves, Agronomy, Crop produc-
tion. Soil investigations. Analytical techniques, Energy budget. Soil-water-
plant relationships, Evapotranspiration, Soil surfaces. Crop response, Thermal
stress, Microenvironment, Standing waters, Plant physiology, Water loss. Remote
sensing.
Identifiers: Leaf energy budget.
In any attempt to arrive at a useful application of remote sensing techniques
in agricultural crop production, a particular radiance or radiance pattern must
be uniquely related to a condition of interest in the soil-crop system. This
work explores the feasibility of the remote detection of water depletion in a
cropped field. It proposes that this may be accomplished by detecting the
increase in the visible and thermal radiant heat loads upon plant leaves when
the underlying soil surface dries. A theoretical model was constructed, relat-
ing leaf temperature to soil surface temperature. Parallel experiments were
done using a grey podzolic soil. In spite of an increase of 15 percent in
reflectivity upon drying, there was an increase in soil surface temperature
from 20 to 50 C. The increased shortwave and longwave radiant loads on
leaf arrays in the experiments resulted in leaf temperature increases of
2.5, 0.5, and 2 C in dry blotting paper, wet blotting paper, and leaves of the
southern pea (Vigna sinensis), respectively. The leaf energy balance-soil
water depletion model predicted these increases, as well as the absolute
temperature, with an accuracy of 1 and 5 percent for the artificial and real
leaves, respectively. Findings affirm that a technology can be developed for
the remote detection of soil water depletion in field crops, but that the
temperature differences involved are both small and variable.
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72-73:07B-003
AERIAL THERMAL SCANNER TO DETERMINE TEMPERATURES OF SOILS AND OF CROP CANOPIES
DIFFERING IN WATER STRESS,
Bartholic, J. F., Namken, L. N., and Wiegand, C. L.
Florida University, Gainesville, Department of Climatology.
Agronomy Journal, Vol. 64, No. 5, p 603-608, 1972. Illus.
Identifiers: "Aerial thermal scanner, *Crop canopies, Gossypium-hirsutum,
*Soils, *Temperatures, Water stress.
An airplane-mounted thermal scanner was used to measure irradiance in the 8-
to 14-micrometer wavelength interval over an extensively instrumented agricul-
tural area. The area included soils differing in water and tillage condition,
and replicated cotton (Gossypium Hirsutum L.) plots with a wide range of plant
water stress. The scanner data were recorded on analog magnetic tape and on
70-mm film. The film densities of the various soil and cotton treatments and
film calibration information were determined with a microdensitometer. The
observed irradiances corresponded to cotton plant canopy temperature differences
up to 6 C between the most and the least water-stressed plots. The irradiance
data from soils showed large differences as a function of time after tillage
and irrigation. Thermal imagery offers potential as a useful aid for delineat-
ing water-stressed and nonstressed fields, evaluating uniformity of irrigation,
and evaluating surface soil water conditions.
72-73:078-004
AN IMPROVED VARIABLE-INTENSITY SPRINKLING INFILTROMETER,
Rawitz, E., Margolin, M., and Hillel, D.
Hebrew University, Jerusalem (Israel), Department of Soil Science.
Soil Science Society American Proceedings, Vol. 36, No. 3, p 533-535, 1972.
Illus.
Identifiers: *Instrumentation, Flow, Infiltration, *Infiltrometers, Intensity,
Movement, Rain, Simulator, Soils, Sprinkling.
Improvements of the Purdue-Wisconsin infiltrometer are described. A winch
was added to the tower to facilitate assembly and the windshield was redesigned.
Water distribution was improved by changes in the revolving shutter and the sur-
plus water collection trough. The nozzle mounting was simplified, and water
level in the vacuum runoff tank was transmitted to an external recorder. Good
uniformity was obtained over a wide range of application rates.
72-73:07B-005
AUTOMATED FLOW-RECORDING SYSTEM FOR FIELD DRAINAGE MONITORINGDIRECT DATA
COMPILATION OF SURFACE AND SUBSURFACE DRAIN FLOW,
Bornstein, J., Preston, H. A., Winant, W. M., and Benoit, G. R.
United States Department of Agriculture, Agricultural Research Service, South
Burlington, Vermont.
Journal of Agricultural Engineering Research, Vol. 18, No. 1, p 31-35, March,
1973. 3 fig, 4 ref.
Descriptors: *Drainage, *Flow measurement, *Data collections, Data storage
and retrieval, Data transmission, Data processing.
An automatic recording console has been developed to accept water stage data
from remote weirs and flumes and store the data on magnetic tape. The sensing-
325
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transmitting-cycling-recording components can economically replace the mechani-
cal-manual systems for converting flow events to card or tape data ready for
computer analysis. A sequence of problems that had prevented operation was
solved and is reported herein.
326
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Section XXXV
RESOURCES DATA
EVALUATION, PROCESSING AND PUBLICATION (Group 07C)
72-73:07C-001
HYMO, A PROBLEM-ORIENTED COMPUTER LANGUAGE FOR BUILDING HYDROLOGIC MODELS,
Williams, J. R. , and Hann, R. W.
Agricultural Research Service, Riesel, Texas, Soil and Water Research Division.
Water Resources Research, Vol. 8, No. 1, p 79-86, February 1972. 1 fig, 1 tab,
13 ref.
Descriptors: *Programming languages, *Computer programs, *Mathematical models,
*Rainfall-runaff relationships, *Routing, Flood routing, Model studies,
Systems analysis. Stage-discharge relations, Hydrographs.
Identifiers: Computer languages, Hymo.
Hymo is a computer language which can be used to great advantages in watershed
modeling. Twelve commands, commonly used in hydrology, transform rainfall into
runoff hydrographs and route these hydrographs through streams and valleys or
reservoirs. These functions make Hymo quite useful in the design and evaluation
of flood control structures, flood forecasting, and research studies. The
procedures used in Hymo were selected because of their accuracy, simplicity,
and practicality. The input data required for Hymo are normally available
for most watersheds. Hymo is quite flexible in that hydrologists familiar
with Fortran 4 programming can easily add new commands or modify the present
commands.
327
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Section XXXVI
ENGINEERING WORKS
STRUCTURES (Group 08A)
72-73:08A-001
COMPARISON OF STRENGTH TEST METHODS FOR CORRUGATED PLASTIC DRAINAGE TUBING,
Scribe, F. I., Fouss, j. L., and Schwab, G. O.
Ohio State University, Columbus.
Transactions of the American Society of Agricultural Engineers, Vol. 15,
No. 3, p 445-447, May-June, 1972. 8 fig, 8 ref.
(See 72-73:02F-062)
328
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Section XXXVII
ENGINEERING WORKS
HYDRAULICS (Group 08B)
72-73:08B-001
GENERALIZED DISCHARGE RELATIONS FOR CUTTHROAT FLUMES,
Skogerboe, G. V., Bennett, R. S., and Walker, W. R.
Colorado State University, Fort Collins.
Journal of Irrigation Drain Division, American Society of Civil Engineers,
Vol. 98, No. IR4, p 569-583, December 1972. 11 fig, 2 tab, 5 ref, 2 append.
Descriptors: Irrigation, Open channel flow, *Discharge measurement, *Water
measurement, Drainage, Flow measurement, Flumes, Design criteria. Hydraulic
structures, Subcritical flow, Laboratory tests. Discharge coefficient. Fluid
mechanics.
Identifiers: *Cutthroat flumes. Hydraulics, Measuring instruments, Parshall
flumes, Submerged flow, Free flow.
The Cutthroat flume, a new flume designed to measure flows in flat gradient
streams, is simple and economical, operates well under submerged flow condi-
tions, and has low head loss. Initial investigations of the flume were limited
to one length of 9 ft with throat widths ranging from 1 to 6 ft, and therefore,
were not geometrically similar. To obtain generalized discharge rating curves
for geometrically similar flumes, a group was rated under both free flow and
submerged flow conditions. Twelve flumes were used in the study - 3 flumes
lengths, 1.5, 3, and 4 ft, with 4 different throat widths for each length.
In addition, the flume sizes were selected to permit correlations with the
initial Cutthroat flume studies. To obtain the most accurate rating, based
upon analysis of data scatters of laboratory ratings, flumes with throat width
to length ratios between 0.1 and 0.4 are recommended. Because of scale effects,
flumes less than 3 ft long are satisfactory only for free flow operations.
Experimental flume dimensions are given; free flow and submerged flow coeffic-
ients and exponents are tabulated.
72-73:086-002
ANALYTICAL FLOW NETS IN CHANNEL SEEPAGE FLOWS,
Bruch, J. C., Jr., and Fernandez Sainz, L. B.
California University, Santa Barbara, Department of Mechanical Engineering.
Water Resources Research, Vol. 8, No. 2, p 519, 524, April'1972. 9 fig, 10 ref.
Descriptors: *Surface-groundwater relationships, *Groundwater movement, *Alluv-
ial channels, *Flow nets, Equations, Seepage, Infiltration, Canal seepage, Open
channeIs.
An analytical solution technique to determine streamlines and equipotential
lines in steady two-dimensional seepage from a single triangular channel into
a permeable soil underlain at a finite depth by a drain was obtained by using
conformal mapping. The technique was applied to triangular channels having side
slopes of 45 deg. The results were compared with those from a published finite
difference solution. The complex integrations were computed by using an inter-
active on line computer system. This computational method proved extremely
easy to apply and a rapid means of obtaining accurate results.
329
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72-73:083-003
SEDIMENT CONTROL METHODS: B. STREAM CHANNELS.
American Society of Civil Engineers, New York, Hydraulics Division.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
98, No. HY7, Paper 9071, p 1295-1326, July 1972. 15 fig, 58 ref.
Descriptors: *Sediment control, *Sediment transport, *Sedimentation, *Erosion,
Sediments, Streams, Channel erosion. Alluvial channels, Sediment load, Sedi-
ment yield.
General knowledge of control of erodible stream channels based on experience
is summarized. Natural and artificial erodible channels are classified, the
types of problems encountered in their control are described and solutions are
outlined. The problems are reviewed in terms of principles, and solutions which
have been successful are described and explained in terms of principles.
72-73:08B- 004
EFFECT OF ROUGHNESS ELEMENTS ON HYDRAULIC RESISTANCE FOR OVERLAND FLOW,
Kowobari, T. S., Rice, C. E., and Carton, J. E.
Soil Testing Services Incorporated, Northbrook, Illinois.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 5,
p 979-984, September-October, 1972. 4 fig, 4 tab, 8 ref.
Descriptors: *Hydraulics, *Open channel flow, *Manning's equation, Fluid
mechanics, Open channels, Hydraulic models, Head loss, Roughness (hydraulic).
Gradually-varied flow experiments were conducted in a 1.32 foot by 24 foot long
test section of a 44 foot long WF steel beam channel. The bottom was lined with
aluminum sheet material which was fitted with round aluminum pegs of sizes
3/32 in. and 9/32 in. diameters. The pegs, which served as roughness elements,
were placed in the channel bed at definite longitudinal and transverse patterns
and spacings. Under the bare channel lining condition, a maximum flow of
0.885 cfs was introduced into the channel. Test slopes for the adjustable
slope channel were restricted to approximate values of 0.0025, 0.0050 and 0.010.
The objective was to determine the relationship of Manning's resistance coeffic-
ient to size of roughness elements, pattern of arrangement, density of spacing,
slope, and discharge in a smooth artificial channel using dimensional analysis
and gradually-varied flow. High correlations between calculated and observed
values of the resistance coefficient were observed for all of the model equa-
tions .
72-73:08B-005
DESIGN CRITERIA FOR IRRIGATION SYSTEMS WITH COMPLEX PIPE LOOPS,
Edwards, D. M., and Spencer, B.
Nebraska University, College of Engineering and Architecture, Lincoln.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 1,
p 76-78, January-February, 1972. 3 fig, 1 tab, 7 ref.
Descriptors: *Irrigation engineering, *Irrigation design, *Sprinkler irriga-
tion, Pipe flow, Pipelines, Hydraulics, Fluid mechanics, Irrigation systems,
Irrigation practices.
A design procedure is presented for the analysis of irrigation systems utiliz-
ing loop networks. The design of these systems are readily adapted to the
digital computer. With the advent of solid set sprinkler, subsurface, and
330
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trickle irrigation systems the simple system layout may no longer be an adequate
design. In these cases loop networks will lower fixed and operation irrigation
costs while developing better water distribution by maintaining more uniform
pressures throughout the system. This design procedure has been used success-
fully in actual field installations it should be emphasized that although the
procedure produces very reliable results, the results of the entire analysis is
only as good as the initial selection of inputs and outputs and human judgments.
72-73:088-006
HYDRAULICS OF A CENTER PIVOT SYSTEM,
Chu, S. T., and Moe, D. L.
South Dakota State University, Agricultural Engineering Department, Brookings.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 5,
p 894-896, September-October, 1972. 3 fig, 1 tab, 4 ref.
Descriptors: *Fluid mechanics, *Pipe flow,*Head loss, Irrigation practices,
Sprinkler irrigation, Hydraulics, Closed conduits, Pressure conduits, Water
distribution (applied), Application methods.
Identifiers: Center pivot system.
The analytical solutions for the total pressure head loss and the distribution
of pressure head loss along the mainline of a center pivot system are presented.
It is shown that the theoretical results are good approximations of practical
field situations. Comparisons of theoretical values and field data are also
presented.
72-73:08B-007
HYDRAULIC ROUGHNESS OF CORRUGATED PLASTIC TUBING,
Irwin, R. W., and Tsang, G.
Guelph University, School of Engineering, Guelph, Ontario, Canada.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 2,
p 290-291, 295, March-April, 1972. 3 fig, 1 tab, 10 ref.
Descriptors: *Plastic pipes, *Tile drains, *Subsurface drains. Hydraulic
conduits, Closed conduits, Fluid friction, Hydraulic design, Reynolds number,
Roughneae (hydra ulic), Turbule nee.
Identifiers: *Corrugated plastic tubing.
The functional relationships between frictional factor, Reynolds number, and
relative roughness are determined for corrugated plastic drainage tubing. All
tubing used was unperforated 4-inch diameter. The test section was 50 feet
in length minus 10 feet at the inlet and 5 feet at the outlet allowed for
end effects. The tubing was maintained full at all flow rates. Friction
factors for corrugated tubing are about twice as great as for well laid tile.
A single value to indicate pipe roughness for hydraulic design cannot be used
for corrugated plastic tubing. A value specific to the tubing used must be
chosen. Plots of data obtained are included.
72-73:088-008
SELF-CLOSING IRRIGATION PIPE VALVE,
Haise, H. R., and Payne, M. L.
United States Department of Agriculture, Fort Collins, Colorado.
331
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Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IR3, p 517-522, September, 1972. 5 fig, 5 ref.
(See 72-73:04A-023)
72-73:088-009
UNIFORM IRRIGATION WITH LOW-PRESSURE TRICKLE SYSTEMS.
Myers, L. E. and Bucks, D. A.
United States Water Conservation Laboratory, Phoenix, Arizona.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 98, No. IRS, p 341-346, September, 1972. 2 fig, 7 ref.
(See 72-73:03F-042)
72-73:08B-010
NUMERICAL SOLUTION OF MULTIPHASE WELL FLOW,
Brutsaert, W.
New Mexico Institute of Mining and Technology, Socorro, Department of* Ground-
Water Hydrology.
American Society of Chemical Engineers Proceedings, Journal of the Hydraulics
Division, Vol. 99, No. HY11, Paper 10162, p 1981-2001, November 1973. 4 fig,
16 ref, append.
Descriptors: *Groundwater movement, *Water wells, *Drawdown, *Oil wells.
Mathematical models, Finite element analysis. Simulation analysis. Porous media,
Oil-Water interfaces.
Identifiers: *Multiphase flow.
A method is presented for numerically solving immiscible multiphase well flow
considering three compressible fluids, two liquids, and one gas, and
assuming isothermal conditions. Capillary and dissolution of gas in liquid
are considered in the proposed mathematical model. Numerical difficulties
arising from the nonlinearity of the equations and from the finite differencing
in cylindrical coordinates are easily dealt with by using a modified Newton
method to solve the fully implicit finite difference equations. Coning prob-
lems in the petroleum industry and unconfined flow problems in hydrology are
typical applications.
72-73:088-011
PROBLEMS AND SCS SPECIFICATIONS FOR LOW HEAD PVC PIPELINES,
Walter, C. L.
Soil Conservation Service, Bozeman, Montana.
Presented at Winter Meetings of the American Society of Agricultural Engineers,
December 11-15, 1972, Chicago, Illinois. 23 p, 6 fig, 3 tab, 2 ref.
Descriptors: *Pipelines, *Plastic pipes, Plastic deformation, Hydraulic struc-
tures, Construction, Deformation, Failures, Specifications.
Survey conducted of low head PVC pipeline installations and further evaluation
of the systems that failed point out the importance of following every require-
ment specified in the design and installation of these systems. Properties of
low head plastic pipe are discussed, and SCS Standards and Specifications for
its use are included.
332
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Section XXVIII
ENGINEERING WORKS
HYDRAULIC MACHINERY (Group 08C)
72-73:08C-001
DEEP PLOWING - AN ENGINEERING APPRAISAL,
James, P. E., and Wilkins, D. E.
United States Department of Agriculture, Agricultural Research Service, Belts-
ville, Maryland.
Transactions of the American Society of Agricultural Engineers, Vol. 15, No. 3,
p 420-422, May-June, 1972. 5 f g, 4 tab, 4 ref.
Descriptors: Cultivation, *Soil management, *Deep tillage, Farm management,
Root zone, Soil treatment, Radioactivity.
Identifiers: Deep plowing.
Tests to determine the benefits and costs of deep plowing were conducted under
six different sets of conditions. Questions to be answered were; limitations
of deep plowing, power requirements, plow modifications needed, and soil
burial pattern. Results ranged from almost no benefit to nearly double
yields. Answers to the questions are as varied as the field conditions. The
need for deep plowing should be evaluated at each location. It is not a
solution to all problems.
72-73:08C-002
A TRACTOR-MOUNTED HYDRAULICALLY-OPERATED SOIL SAMPLER FOR RAPID SOIL CORING,
Schickedanz, D. M., Onken, A. B., Cummings, T., and Jones, R. M.
Texas A & M University, Agricultural Experiment Station, Lubbock.
Agronomy Journal, Vol. 65, No. 2, p 339-340, March-April, 1973. 2 fig.
Descriptors: *Core drilling, *Cores, Hydraulic equipment, Soil profiles.
A tractor-mounted hydraulically-operated soil sampler has been developed that
incorporates a number of features required for extensive soil sampling. Speed,
adaptability, mobility, accessibility, and safety are advantages of this
equipment which are not all sufficiently adequate in currently available models.
333
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Section XXXIX
ENGINEERING WORKS
SOIL MECHANICS (Group 08D)
72-73-08D-001
A LARGE, UNDISTURBED, WEIGHING LYSIMETER FOR GRASSLAND STUDIES,
Armiho, J.D., Twitchell, G.A. , Burman, R.D., and Nunn, J.R.
Wyoming University, Laramie.
Transactions of the American Society of Agricultural Engineers, Vol 15,
No 5, p 827-830, September-October, 1972. 6 fig, 7 ref.
(See 72-73:02G-031)
72-73:080-002
PREDICTING OPTIMUM DEPTH OF PROFILE MODIFICATION BY DEEP PLOWING FOR
IMPROVING SALINE-SODIC SOILS,
Rasmussen, W.W., and McNeal, B.L.
United States Department of Agriculture, Kimberly, Idaho.
Soil Science Society of America Proceedings, Vol 37, No 3, p 432-437,
May-June, 1973. 2 fig, 3 tab, 14 ref.
(See 72-73:026-134)
72-73:080-003
BULK DENSITY OF A FRAGIPAN SOIL IN NATURAL AND DISTURBED PROFILES,
Fritton, D.D. and Olson, G.W.
Pennsylvania State University, Agronomy Department, University Park
Soil Science Society of America Proceedings, Vol 36, No 4, p 686-689,
July-August, 1973. 3 tab, 7 ref.
Descriptors: *Soil physics, *Soil density, Soil compaction, Soil horizons,
Soil profiles, Soil properties, Soil structure, Soil texture, Soil types,
Soils.
Bulk density of horizons and layers in soil profiles at two locations (for
natural soil and soil above pipelines and tileline) showed that modification
of the Erie channery silt loam fragipan by mechanical disturbance alone
results in re-establishing dense soil layers in less than 11 years.
Buried topsoil, however, was much less dense after 12 years.
334
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Section XXXX
ENGINEERING WORKS
RAPID EXCAVATION (Group 08H)
72-73:08H-001
DELAYS IN THE OPERATION OF SUBSURFACE DRAINAGE TRENCHING MACHINES,
Fisk, S. D., Broughton, R. S., and Norris, E. R.
Quebec Ministry of Agriculture and Colonization, Buckingham, Quebec, Canada.
Canadian Agricultural Engineering, Vol. 14, No. 2, p 69-71, December, 1972.
1 fig, 2 tab, 3 ref.
(See 72-73:020-171)
335
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Section XXXXI
SCIENTIFIC AND TECHNICAL INFORMATION
ACQUISITION AND PROCESSING (Group 10A)
72-73:10A-001
A QUICK-WEIGHING LYSIMETER SYSTEM CHECK,
Middleton, J. E.
Washington State University, Irrigated Agriculture Research and Extension
Center, Prosser.
Agricultural Engineering, Vol. 53, No. 7, p 14-15. July, 1973. 1 fig.
Descriptors: *Lysimeters, Instrumentation, Moisture meters, Moisture content,
Soil water, Evapotranspiration.
A quick dynamic lysimeter sensitivity check has been developed in which a
5 gallon water-filled container is placed on top of the soil at the center
of a lysimeter. A 1/32-inch ID copper tube is soldered into the base of the
container to slowly drain the water from the container and away from the
lysimeter. Any operational malfunction will be indicated by an irregularity
in the plotted time:weight loss curve.
72-73:10A-002
RECORDING WATER USE BY MEANS OF DIGITAL EQUIPMENT,
Payne, L.F., and Schreiber, H. A.
Southwest Watershed Research Center, Tucson, Arizona.
Agronomy Journal, Vol. 64, No. 1, p 83-84, January-February, 1972. 1 fig.
Descriptorst *Water utilization, Measurement, Hydroponics, Data collections,
Data storage and retrieval.
A device made of digital components is described that automatically (i) senses
a discrete loss of water in individual hydroponic cultures; (ii) stores this
information as identifying numbers in an 8 2-digit word memory; and (iii)
displays this information on an electric typewriter at 1-minute intervals.
As many as 16 readings a day can be obtained in a greenhouse, if the ratio of
leaf area to water surface area is high enough. This equipment, then, gives
a sensitive measurement of water use related to climatic, genetic, or physiolo-
gic treatments.
72-73:10A-003
REFLECTANCE DISCRIMINATION OF COTTON AND CORN AT FOUR GROWTH STAGES,
Gausman, H. W., Allen, W. A., Cardenas, R., and Richardson, A. J.
United States Department of Agriculture, Agricultural Research Service, Weslaco,
Texas.
Agronomy Journal, Vol. 65, No. 2, p 194-198, March-April, 1973. 6 fig, 1 tab,
12 ref.
Descriptors: *Reraote sensing, ^Reflectance, Infrared radiation. Instrumenta-
tion, Surveys, Corn, Cotton.
Increasing leaf age of corn within four growth stages had little effect on
near-infrared light reflectance than young leaves. Reflectance was linearly
correlated with chlorophyll concentration for the four growth stages of corn
336
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at the 550-nm wavelength; the linear correlation of reflectance with chlorophyll
for the four growth stages of cotton was significant at the 650-nm wavelength.
The largest differences among reflectances of corn leaves of different ages
within growth stages occurred when tassels were appearing in the leaf whorls;
this may be the best time to discriminate corn from other vegetation with
remote sensors. Reflectance differences among cotton leaves within the four
growth stages were similar. Spectral wavelength intervals centered around the
680-, 850-, 1,650-, and 2,200-nm wavelengths provide for the optimum discrimina-
tion of vegetation.
337
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Section XXXXII
AUTHOR INDEX
Aarstad, J. S.
72-73:020-026
72-73:03F-033
Abiodun, A. A.
72-73:048-016
Abouel Nour, A-R.
72-73:058-009
Adamowski, K
72-73:02P-038
Adams, F
72-73:02G-077
Adriano, D. C.
72-73:020-106
72-73:03F-015
72-73:05B-050
72-73:05B-086
Adyalkar, P. G.
72-73:02F-044
Afghan, B. K.
72-73:05A-005
Agarwal, S. C.
72-73:03F-008
72-73s04A-042
Ahmed, J.
72-73:020-222
Ahuja, L. R.
72-73:020-013
72-73:020-017
72-73:020-035
Albregts, E. E.
72-73:020-189
Alessi, J.
72-73:058-080
Allen, A. L.
72-73:058-043
Allen, D. M.
72-73:020-177
Allen, P. 8.
72-73:02J-004
Allen, R. R.
72-73:020-032
72-73:020-129
Allen, W. A.
72-73:10A-003
Allen, W. H.
72-73:020-157
Allison, G. B.
72-73:02F-042
72-73:02F-043
Allred, E. R.
72-73:020-210
Alperovits, E.
72-73:03F-014
Amara, J.
72-73:02G-141
Anaya, M. G.
72-73:03F-049
Arbhabhirama, A.
72-73:02F-039
Ardakani, M.S.
72-73:020-140
Arm!jo, J. D.
72-73:020-031
Armstrong, D. L.
72-73:021-002
Arnold, G. C.
72-73:02D-022
72-73:04A-025
Ashcroft, G. L.
72-73:020-224
72-73:03F-022
Asmussen, L. E.
72-73:02F-021
72-73:058-036
Asseed, M. S.
72-73:020-113
72-73:04A-034
Aston, A. R.
72-73:078-002
Asubnandan, K.
72-73:02J-003
Atkinson, T. C.
72-73:02F-078
Aunimelech, Y.
72-73:056-063
Austin, R. S.
72-73:020-108
72-73:026-156
Austin, T. A.
72-73:056-015
Awan, N. M.
72-73:026-005
Ayers, R. S.
72-73:03F-034
Aylor, D. E.
72-73:020-025
Babcock, K. L.
72-73:020-225
72-73:02K-009
Baker, C. H.
72-73:021-018
Baker, D. E.
72-73:020-115
Baker, D. G.
72-73:03F-024
Bailey, J. W.
72-73:05F-003
Barber, S. A.
72-73:020-020
Barefoot, A. D.
72-73:03F-068
Bargur, J.
72-73:06A-002
Barica, J.
72-73:048-030
338
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Barker, J. C.
72-73:05D-007
Bartholic, J. F.
72-73:07B-003
Bartlett, R. J.
72-73:056-048
Bar-Yosef, B.
72-73:020-142
Bassett, D. L.
72-73:04A-008
Batchelder, D. C.
72-73:021-004
Bennett, A. G.
72-73:020-077
Bennett, R. S.
72-73:086-001
Benoit, G. R.
72-73:04A-031
72-73:056-020
72-73:078-005
Benson, N. R.
72-73:020-101
Benz, C.
72-73:048-011
Benz, R. C.
72-73:04A-045
72-73:04A-046
Berlament, J.
72-73:04A-037
Bernal, R.
72-73:026-159
72-73:03F-013
Berndt, H. D.
72-73:02J-005
Bernstein, L.
72-73:050-008
Bhuiyan, S. I.
72-73:020-222
Bielorai, H.
72-73:020-041
Biggar, J. W.
72-73:020-002
Biggar, J. W.
(Cont.)
72-73:020-060
72-73:020-082
72-73:020-086
72-73:020-109
72-73:02K-004
Bingham, F. T.
72-73:020-130
72-73:020-144
72-73:030-007
Biswas, D.
72-73:020-074
Bittinger, M. W.
72-73:06E-003
Black, A. L.
72-73:020-136
Blackman, W. C., Jr.
72-73:058-027
Blad, B. L.
72-73:0,3F-024
Blake, G. R.
72-73:020-024
72-73:020-149
Blanc, F. C.
72-73:058-093
Blanchar, R. W.
72-73:020-055
Blasius, M. B.
72-73:05A-001
Blevins, R. L.
72-73:02D-037
Blue, T.
72-73:050-010
Blum, A.
72-73:021-014
72-73:03F-031
Boelter, D. H.
72-73:04A-033
Bonn, H. L.
72-73:03A-001
Bond, J. G.
72-73:050-002
Bond, J. J.
72-73:020-027
72-73:020-208
Bondurant, J. A.
72-73:058-007
Bonell, M.
72-73:02F-049
Bonnier, A.
72-73:056-026
Boonkird, U.S.
72-73:04A-041
Borelli, J.
72-73:03F-011
8orn, S. M.
72-73:02J-002
Bornstein, J.
72-73:04A-031
72-73:076-005
Boulton, N. S.
72-73:02F-052
Bouraa, J.
72-73:020-022
72-73:020-097
72-73:058-039
72-73:058-040
Bowen, D. K.
72-73:050-006
Bowen, H. D.
72-73:021-004
Bower, C. A.
72-73:020-021
72-73:020-120
Bowers, S. A.
72-73:020-148
Bradley, J. R., Jr.
72-73:058-004
Braester, C.
72-73:020-011
Branson, F. H.
72-73:02D-005
Bredehoeft, J. D.
72-73:02F-030
72-73:048-010
339
-------
Bremmer, J. M.
72-73:02K-010
Bremner, J. M.
72-73:05B-053
Bresler, E.
72-73:020-023
72-73:020-036
72-73:020-147
72-73:030-001
Brockway, D. L.
72-73:050-001
Broughton, R. S.
72-73:020-171
Brown, G., Jr.
72-73:046-009
Buchanan
72-73:020-123
Bucks, D. A.
72-73:03F-042
72-73:04A-070
Buitot, F.
72-73:020-030
Buras, N.
72-73:03F-014
Burman, R. D.
72-73:020-031
Burnett, E.
72-73:02D-018
72-73:020-058
72-73:020-063
Campbell, R. B.
72-73:03F-058
Capiel, M.
72-73:03F-022
Carbonell, M. D.
72-73:020-145
Cardenas, R.
72-73:10A-003
Carlson, R. M.
72-73:020-123
Carmi, I.
72-73:02F-077
Carter, C. E.
72-73:020-166
Brown, H. E.
72-73:03B-001
Burt, O. R.
72-73:03F-021
Carter, D. L.
72-73:020-176
Brown, J. H.
72-73:02D-013
Brown, K. W.
72-73:020-194
Brown, M. C.
72-73:02F-041
Brown, R. F.
72-73:046-003
Browning, V. D.
72-73:021-019
Bruce, R. R.
72-73:020-088
Bruch, J. C., Jr.
72-73:02F-033
72-73:08B-002
Bruington, A. E.
72-73:048-002
Brun, L. J.
72-73:020-019
72-73:021-012
Brutsaert, W.
72-73:088-010
Bubenzer, G. D.
72-73:03F-067
Burwell, R. E.
72-73:020-066
72-73:02J-009
72-73:056-058
72-73:05B-075
Burzlaff, D. F.
72-73:056-082
Busch, C. D.
72-73:020-020
72-73:020-162
Busch, J. R.
72-73:05C-004
Byers, G. E.
72-73:020-068
72-73:056-065
Byers, G. L.
72-73:020-032
Cady, F. B.
72-73:020-177
Cain, J. M.
72-73:040-004
Calissendorff
72-73:020-084
Campbell, G. S.
72-73:020-084
Gary, J. W.
72-73:020-087
72-73:020-091
Castillo, Enrique
72-73:02F-022
Catton, I.
72-73:048-014
Chamblee, D. S.
72-73:03F-059
Chang, A. C.
72-73:058-086
Chauhan, H. S.
72-73:020-046
72-73:04A-075
Chen, R. L.
72-73:02H-001
72-73:058-002
Chen, T. C.
72-73:06A-004
Cheng, H. H.
72-73:020-101
Cheng, R. T. S.
72-73:020-167
Cheong, H. F.
72-73:02J-011
340
-------
Chery, D. L., Jr.
72-73:020-152
Cheaters, G.
72-73:056-008
Chhatwal, Surjit S.
72-73:02F-034
Chow, T. L.
72-73:020-092
Chu, S. T.
72-73:020-218
72-73:088-006
Cisler, Jaromir
72-73:020-003
Clanton, D. C.
72-73:04A-015
Clark, M.
72-73:04C-001
Clark, W. L., III
72-73:05D-010
Clever, Richard M.
72-73:04B-014
Cochran, V. L.
72-73:020-200
72-73:020-227
Collins, H. 6.
72-73:04A-072
Colwick, R. F.
72-73:02A-006
72-73:021-004
Colyer, D.
72-73:05B-078
Conner, L. J.
72-73:021-002
Cooke, G. W.
72-73:05B-095
Cooley, R. L.
72-73:02F-018
Cormack, J. M.
72-73:02J-012
Cothern, C. R.
72-73:05A-001
Cox, L. M.
72-73:020-164
Cox, R. L.
72-73:02F-034
Craven, S. E.
72-73:05C-001
Cristiansen, J. E.
72-73:020-212
Cross, O. E.
72-73:020-165
Cummings, T.
72-73:08C-002
Cykler, J. F.
72-73:04A-063
Dagan, G.
72-73:02F-004
Dague, R. R.
72-73:02E-013
Dailey, R. T.
72-73:053-089
Daniel, W. H.
72-73:020-198
Danielson, J. A.
72-73:04B-007
Davenport, L. A.
72-73:058-084
Davidson, B.
72-73:050-001
Davidson, J. M.
72-73:020-127
72-73:058-059
Davis, C. H.
72-73:03F-071
72-73:04A-080
Davis, J. F.
72-73:020-065
72-73:058-057
Davis, R. G.
72-73:020-191
Davis, R. W.
72-73:02F-008
Davis, S.
72-73:02F-068
Dawson, M. D.
72-73:05B-077
Day, J. C.
72-73:02E-006
Deacon, R.
72-73:048-009
De Boer, D. W.
72-73:020-218
Dedrick, A. R.
72-73:04A-04D
de Jong, E.
72-73:03F-029
Denning, J. L.
72-73:020-097
der Beken, A. V.
72-73:04A-037
De Renter, E. D.
72-73:020-175
Desai, C. S.
72-73:02F-069
72-73:020-070
De Vriea, J.
72-73:020-092
Dhua, S. P.
72-73:020-074
Dickens, W. L.
72-73:021-007
Dickey, G. L.
72-73:020-161
72-73:05F-003
Dillon, R. C. Jr.
72-73:03F-003
Dinoy, A. A.
72-73:02F-039
Di Toro, M.
72-73:05B-010
Dixon, R. M.
72-73:020-064
72-73:020-094
72-73:020-223
341
-------
Doering, E. J.
72-73:04B-011
Doll, J. P.
72-73:05B-078
Dutt, G. R.
72-73:020-211
Dylla, A. S.
72-73:020-164
Etzel, J. E.
72-73:05A-004
Evans, J. O.
72-73:05B-094
Domenico, P. A.
72-73:02K-003
Doneen, L. D.
72-73:03F-034
Donnan, W. W.
72-73:020-215
Dotzenko, A. D.
72-73:03F-025
Dougherty, C. T.
72-73:021-003
Douglas, C. L.
72-73:056-007
72-73:05C-003
Downey, L. A.
72-73:020-047
Drake, J. J.
72-73:02K-006
Duble, R. L.
72-73:056-041
72-73:058-042
Duckstein, L.
72-73:02F-014
Dudas, M. J.
72-73:020-138
Dudley, N. J.
72-73:03F-004
72-73:03F-006
72-73:03F-021
Duke, H. R.
72-73:02F-061
72-73:020-114
Dupriez, G. L.
72-73:020-030
Duseja, D. R.
72-73:056-094
Dusek, D. A.
72-73:04A-069
Earles, J. D.
72-73:03F-039
Eastin, J. D.
72-73:021-014
Edwards, A. M. C.
72-73:056-019
Edwards, A. P.
72-73:056-037
Edwards, D. M.
72-73:04A-017
72-73:086-005
72-73:056-034
Edwards, W. M.
72-73:040-003
Ehhalt, D. H.
72-73:02F-055
Ehrler, w. L.
72-73:020-204
Eisel, L. M.
72-73:040-001
Eldor, Menahem
72-73:02F-004
Elliott, L. F.
72-73:056-018
Ellis, J. R.
72-73:056-018
El Nimr, A.
72-73:02F-056
Enfield, C. G.
72-73:02F-080
England, C. 6.
72-73:020-012
Epstein, E.
72-73:020-202
Brickson, L. E.
72-73:056-068
Evans, S. D.
72-73:020-185
Fairbourn, M. L.
72-73:020-146
72-73:03F-061
Fan, L. T.
72-73:056-068
Farquhar, G. J.
72-73:056-092
Farrell, D. A.
72-73:02F-016
72-73:020-149
Fausey, N. R.
72-73:02G-216
Feddes, R. A.
72-73:020-169
72-73:03F-0>2-
Felizardo, 6. C.
72-73:020-101
Fernandez Sainz, L. B.
72-73:086-002
Ferrar, T. A.
72-73:050-005
Ferry, G. V.
72-73:03F-034
Fischbach, P. E.
72-73:020-165
72-73:03F-064
72-73:056-034
Fischer, R. C,
72-73:020-033
Fisk, S. D.
72-73:020-171
Fitzgerald,'P. D.
72-73:020-022
72-73:04A-025
Fitzsimmons, D. W.
72-73:020-037
342
-------
Fitzsimmons, D. W.
(Cont.)
72-73:020-045
72-73:050-004
Flaxman, E. M.
72-73:02J-006
Frind, E. O.
72-73:02F-002
72-73:02F-032
72-73:02F-037
Fritton, D. D.
72-73:080-003
Ghorashy, S. R.
(Cont.)
72-73:030-004
Giesel, W.
72-73:02F-076
72-73:020-009
Fleming, W. G.
72-73:02J-010
Frost, K. R.
72-73:020-172
Giglio, R. J.
72-73:05D-003
Floyd, J. M.
72-73:02G-166
Focht, D. D.
72-73:05B-049
72-73:053-061
Foley, J.
72-73:050-012
Follett, R. F.
72-73:020-205
Folwell, R. J.
72-73:05B-089
Forbes, R. B.
72-73:058-052
Foster, E. T., Jr.
72-73:06A-004
Foster, G. R.
72-73:02E-007
Foyster, A. M.
72-73:02D-027
Francois, L. E.
72-73:030-003
72-73:050-008
Frank, A. B.
72-73:021-015
Frazier, R. D.
72-73:020-185
Freeze, R. A.
72-73:02A-001
72-73:02A-002
Frere, M. H.
72-73:056-024
Frick, P.
72-73:066-001
Fuehring, H. D.
72-73:021-011
Gabriels, D. M.
72-73:04D-002
Gambolati, Giuseppe
72-73:02F-036
72-73:02F-058
Garber, M. J.
72-73:02G-179
Gardner, H. R.
72-73:020-024
Gardner, W. H.
72-73:020-084
Gardner, W. R.
72-73:03F-028
Garton, J. E.
72-73:04A-009
72-73:086-004
Gausman, H. W.
72-73:021-017
72-73:10A-003
Gavish, Y.
72-73:02G-041
Gelhar, Lynn W.
72-73:02F-027
Gerard, C. J.
72-73:020-184
72-73:05C-009
Ghandi, B.
72-73:02F-034
Ghildyal, B. P.
72-73:021-008
Ghorashy, S. R.
72-73:026-195
Gill, W. R.
72-73:020-039
Gilley, J. R.
72-73:020-210
72-73:020-213
72-73:04A-038
Gilliland, J. A.
72-73:02F-038
Gilmour, J. T.
72-73 :02G-125
Gisser, M.
72-73:02F-073
72-73:060-001
Gitlin, H. M.
72-73:04A-073
Glancy, P. A.
72-73:02J-002
Glover, R. E.
72-73:02F-023
72-73:04A-001
Goertzen, J. O.
72-73:02K-007
Gonzalez, C. L.
72-73:020-192
Good, J. M.
72-73:056-060
Goodin, J. R.
72-73:030-003
Gotoh, S.
72-73:02G-098
Goulden, P. D.
72-73:05A-005
Graetz, D. A.
72-73:056-002
343
-------
Grant, W. J.
72-73:020-202
Grass, L. B.
72-73:020-030
72-73:026-103
72-73:020-105
72-73:04A-005
72-73:05F-003
Graves, G. W.
72-73:050-004
Greb, B. W.
72-73:02J-014
Green, D. W.
72-73:02F-034
Greenkorn, R. A.
72-73:058-022
Greenway, H.
72-73:030008
Gregg, J. C.
72-73t05F-004
Greweling, T.
72-73:058-029
Griffin, R. A.
72-73:020-126
Griffis, C. L.
72-73:02P-066
Grimes, D. W.
72-73:021-007
Grunes, D. L.
72-73:05B-080
Gumbs, F. A.
72-73:026-100
Gupta, S. C.
72-73020-059
72-73:056-022
Gupta, U. C.
72-73:020-122
Ouron, Y.
72-73:020-153
Gustafson, C. D.
72-73:04A-060
Guymon, G. L.
72-73:02E-001
Gyuk, I.
72-73:02F-075
72-73:02F-079
Hagan, R. M.
72-73:020-011
72-73:020-069
72-73:06A-005
72-73:03F-010
72-73:03F-046
Hagood, M. A.
72-73:03F-057
Hahne, H. C* H.
72-73:026-124
Haimes, Y. Y.
72-73*056-002
72-73:056-012
Baise, H. R.
72-73:026-114
Haith, D. A.
72-73:05D-008
Halepaska, J. C.
72-73:02F-003
Hall, F. R.
72-73:02A-004
Hall, 6. F.
72-73:04D-003
Hall, J. K.
72-73:058-035
Hall, W. A.
72-73:03F-018
72-73:06A-005
Han, G. E.
72-73:026-185
Hamilton, R. A.
72-73:058-062
Hammond, L. C.
72-73:026-104
72-73:026-199
72-73:03F-060
Hanks, R. J.
72-73:026-059
72-73:026-110
Hanks, R. J.
(Cont.)
72-73:026-111
72-73:050-016
Harm, R. W.
72-73:070-001
Hansen, L. H.
72-73:021-010
Hanshaw, B. B.
72-73:02K-005
Hargrove, S. H.
72-73:06D-002
Haridasan, M.
72-73:026-096
Harmon, R. S.
72-73:02K-006
Harper, L. A.
72-73:02D-035
Harr, R. D.
72-73s02D-002
Harris, D. G.
72-73:021-015
Hart, W. E.
72-73:03F-011
72-73:04A-020
Hassan, A. A.
72-73:02A-008
Hassett, J. J.
72-73:058-083
Hauck, R. D.
72-73:026-132
72-73:058-072
72-73:058-054
Hauser, E. W.
72-73:058-036
Hawkins, R. H.
72-73:058-014
Heady, E. O.
72-73:06D-002
Healy, K. A.
72-73:026-072
72-73:058-028
344
-------
Heaney, J. P.
72-73:05B-017
Heermann, D. P.
72-73:04A-007
72-73:04A-067
Hillel, D.
(Cont.)
72-73:07B-004
Hinojosa, E.
72-73:05C-009
Howell, D. T.
72-73:03F-004
Howell, T. A.
72-73:020-163
72-73:03F-063
Heilman, M. D.
72-73:026-192
Hinze, G. O.
72-73:03F-025
Hsie, C. H.
72-73:02F-005
Hellwig, D. H. R.
72-73:02D-014
72-73:020-015
72-73:020-028
72-73:020-029
Hem, J. D.
72-73:02K-001
Henderlong, P. R.
72-73:020-228
Hobbs, E. H.
72-73:020-031
72-73:020-033
Hoffman, G. J.
72-73:02B-001
72-73:02G-156
72-73:030-005
72-73:030-009
72-73:03F-001
72-73:03F-019
Hsieh, J. J. C.
72-73:02F-080
Huang, Y. H.
72-73:043-015
Huber, M. J.
72-73:02F-071
Huber, W. C.
72-73:053-017
Henderson, D. W.
72-73:02G-109
Holburt, M. B.
72-73:030002
Huck, M. G.
72-73:02G-197
Henderson, R. C.
72-73:020-018
Holding, A. J.
72-73:056-002
Huggins, L. F.
72-73:020-158
Herbert, R.
72-73:02F-046
Holmes, J. W.
72-73:02F-042
Hughes, M. W.
72-73:02F-043
Hermanson, R. E.
72-73:020-170
Hermsmeier, L. F.
72-73:020-160
72-73:03F-002
72-73:03F-066
Herrera, I.
72-73:02F-060
Hibbert, A. R.
72-73:020-154
Higgins, E. R.
72-73:05B-035
Hiler, E. A.
72-73:020-163
72-73:02G-222
72-73:021-005
72-73:03F-003
72-73:03F-063
72-73:03F-072
Hill, J. D.
72-73:020-037
Hillel, D.
72-73:020-153
Holt, R. F.
72-73:05B-023
72-73:05B-075
Holtman, J. B.
72-73:021-002
Hornsby, A. G.
72-73:020-127
72-73:050-015
Horrocks, R. D.
72-73:021-018
Horton, M. L.
72-73:020-203
72-73:020-206
Hortenstine, C. C.
72-73:053-052
Horvath, D. J.
72-73:026-228
Hossain, M. M.
72-73:021-005
Howard, C. M.
72-73:020-189
Hughes, W. C.
72-73:020-012
Hunsaker, V. E.
72-73:056-001
Hunt, Bruce W.
72-73:02F-026
72-73:04A-006
Hunter, J. Stuart
72-73:02A-003
Hurle, D. H.
72-73:02K-002
Husar, M. A., Jr.
72-73:050-002
Igwe, O. C.
72-73:020-034
Ingvalson, R. D.
72-73:040001
Irwin, R. W.
72-73:086-007
345
-------
Israelsen, E. K.
72-73:058-016
Isu, E. O.
72-73:06A-004
Jackson, M. D.
72-73:05B-004
Jackson, R. D.
72-73:02D-023
72-73:02D-025
72-73:020-076
Jackson, R. E.
72-73:02P-038
Jackson, W. A.
72-73:058-036
Jacobs, H. S.
72-73:021-013
Jacobs, M. L.
72-73:050-003
Jacobsen, P.
72-73:020-214
Jacoby, H. D.
72-73:06A-003
James, P. E.
72-73:080-001
James, R. V.
72-73:02F-017
72-73*058-021
James, W.
72-73ğ02A-007
Jaranyi, G.
72-73:020-215
Jeffers, D. L.
72-73:020-207
Jennings, H. E.
72-73s02E-002
72-73:058-013
Jensen, M. E. .
72-73J02D-006
72-73:04A-068
Jensen, R. D.
72-73:020-096
Jernigan, C. L.
72-73:020-162
Jobling, G. A.
72-73:04A-028
Jobson, H. E.
72-73:02D-003
Johns, R. W.
72-73:058-089
Johnson, W. C.
72-73:020-191
Johnson, W. K.
72-73:05D-009
Jones, 8. A., Jr.
72-73:04A-012
72-73:058-084
Jones, E. B.
72-73:06E-003
Jones, G. D.
72-73:020-178
Jones, J. W.
72-73:02A-006
Jones, O. R.
72-73:048-005
Jones, R. M.
72-73:080-002
Jones, W. W.
72-73:058-001
Jordan, W. R.
72-73:02D-017
72-73:021-005
Joseph, H. A.
72-73:058-049
Judd, J. H.
72-73:058-014
Jung, P. E., Jr.
72-73:020-180
Jurinak, J. J.
72-73:020-001
72-73:020-099
72-73:020-126
72-73:058-083
Kaddah, M. T.
72-73:026-188
72-73:03F-066
Kafkafi, U.
72-73:020-142
Kamprath, E. J.
72-73:058-081
Kanemasu, E. T.
72-73:02D-019
72-73:021-012
72-73:021-013
Kang, S. T.
72-73:04A-018
Kao, C. W.
72-73:02G-055
Kaplan, M. A.
72-73:050-002
Karadi, Gabor M.
72-73:02F-022
72-73:02F-075
Kaufman, A.
72-73:02F-077
Kay, B. D.
72-73:020-102
Keefer, R. F.
72-73:020-228
Keeney, D. R.
72-73:02H-001
72-73:058-002
72-73:058-039
72-73:058-040
72-73:050-002
Keller, J.
72-73:020-224
Kelley, G. E.
72-73:040-003
Kemper, W. D.
72-73:020-089
Kerkhoff, S. J.
72-73:05A-001
Kerr, P. C.
72-73:050-001
346
-------
Ketcheson, J. W.
72-73:02J-013
Kheradnam, M.
72-73:020-195
72-73:03C-004
Kichen, J. H.
72-73:020-061
Kilpatrick, P. A.
72-73:078-001
Kimball, B. A.
72-73:02D-023
72-73:02D-025
72-73:02D-026
Kimble, J. M.
72-73:058-048
Kincaid, D. C.
72-73:04A-007
King, L. G.
72-73:050-016
Kinjo, T.
72-73:020-141
Kipp, K. L., Jr.
72-73:02F-029
Kirda, C.
72-73:02K-004
Kirkham, D.
72-73:020-019
72-73:020-128
72-73:04A-035
72-73:040-002
Kisiel, C. C.
72-73:02F-014
Kissel, D. E.
72-73:020-058
72-73:020-063
Kittock, D. L.
72-73:03F-062
Klausner, S. D.
72-73:058-048
Klepper, B.
72-73:020-197
72-73:021-009
72-73:021-019
Klute, A.
72-73:03F-023
Knezek, B. D.
72-73:020-065
72-73:058-057
Koch, D. W.
72-73:03F-025
Kohl, R. A.
72-73:020-029
72-73:04A-065
Konrad, J. G.
72-73:04D-004
Korganoff, A.
72-73:058-026
Kott, Y.
72-73 :,05D-013
Kowalenko, C. G.
72-73:02K-008
Kowobari, T. S.
72-73:088-004
Kriz, G. J.
72-73:020-159
72-73:03F-013
Kriz, H.
72-73:02F-051
Kirzek, R. J.
72-73:02F-022
72-73:02F-079
Krone, R. B.
72-73:02J-003
Kroontje, W.
72-73:020-124
Kroth, E. M.
72-73:058-078
Krueger, C. R.
72-73:021-010
Krupp, H. K.
72-73:020-086
Kruse, E. G.
72-73:04A-007
Kuhnle, J. A.
72-73:05D-006
Kuiper, L. K.
72-73:02F-009
Kuiper, L. K.
(Cont.)
72-73:02F-011
72-73:02F-054
Kurtz, L. T.
72-73:020-132
72-73:020-135
72-73:020-226
72-73:058-043
72-73:05B-072
Laak, R.
72-73:058-028
Lai, R. Y.
72-73:04A-021
Lai, S. H.
72-73:020-001
72-73:020-099
72-73:058-083
Lakshman, G.
72-73:02D-016
Lance, J. C.
72-73:05D-012
Langdale, G. W.
72-73:020-209
Lao, C.
72-73:058-088
Laopirojana, P.
72-73:058-077
Lars on, C. L.
72-73:020-006
Larson, W. E.
72-73:02F-016
Lathwell, D. J.
72-73:058-029
Laudelout, H.
, 72-73:020-016
Lavis, J. J.
72-73:02F-078
Law, J. P., Jr.
72-73:050-001
Lawless, G. P.
72-73:02D-008
72-73:048-008
347
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Leggett, G. E.
72-73:026-176
Lehman, W. F.
72-73:02G-188
Lembke, W. D.
72-73:04A-012
72-73:05B-084
Leonard, R. A.
72-73:02J-010
Letey, J.
72-73:02G-083
Levi, D.
72-73:026-201
Lewis, G. C.
72-73:050-004
Li, C. Y.
72-73:026-167
Liang, T.
72-73:03P-007
Ligon, J. T.
72-73:026-043
Lin, C. L.
72-73:02F-015
Lin, S. S.
72-73:026-170
Linden, D. R.
72-73:026-064
72-73:026-223
Lindstrom, M. J.
72-73:026-227
Littleton, T. 6.
72-73:026-209
Loehr, R. C.
72-73:058-067
Logan, T. J.
72-73:053-069
Lorenz, O. A.
72-73:03F-015
Lorimor, J. C.
72-73:05B-018
Loucks, D. P.
72-73:06A-003
Lovell, R. E.
72-73:02F-014
Lowe, L. E.
72-73:02K-008
Lundy, H. W.
72-73:03F-060
Lusby, 6. C.
72-73:02D-005
Lutz, J. F.
72-73:026-068
72-73:05B-065
McCauley, 6. N.
72-73:026-081
McCormick, R. L.
72-73:043-008
McCready, R. M.
72-73:05D-006
McCurdy, R. M.
72-73:026-104
McDougal, J. R.
72-73:058-059
McGuiness, J. L.
72-73:02D-009
72-73:04D-003
Mclntosh, J. L.
72-73:058-048
McLean, E. O.
72-73:026-145
72-73:058-069
72-73:058-091
72-73:026-220
Maas, E. V.
72-73:05C-007
72-73:026-179
72-73:030-005
72-73:03C-006
72-73:030-009
MacKenzie, A. J.
72-73:026-030
72-73:026-103
72-73:026-105
72-73:045.-005
Haddock, T., III
72-73:06A-001
Madhav, M. R.
72-73:04A-036
Madsen, H. C.
72-73:06D-002
Magdoff, F. R.
72-73:058-040
Mani, V. V. S.
72-73:02F-044
Mann, L. D.
72-73:058-049
Mannering, J. V.
72-73:02E-011
Manse11, R. S.
72-73:026-104
Marani, A.
72-73:026-201
Margolin, M.
72-73:078-004
Marino, M. A.
72-73:02F-025
72-73:02F-050
72-73:02F-053
72-73:02F-082
Marion, G. M.
72-73:026-225
72-73:02K-009
Long, R. P.
72-73:026-072
Longenbaugh, R. A.
72-73:058-012
McMichael, F. C.
72-73:02A-003
McNeal, B. L.
72-73:026-134
Martens, D. C.
72-73:026-173
Massie, L. R.
72-73:026-217
348
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Matocha, J. E.
72-73:056-041
72-73:05B-042
Mayland, H. F.
72-73:020-087
Mazor, E.
72-73:02P-077
72-73:058-076
Mederski, H. J.
72-73:020-207
Meek, B. D.
72-73:02F-071
72-73:020-103
72-73:020-105
72-73:05F-003
Mehran, M.
72-73:020-109
Mein, R. G.
72-73:020-006
Meints, V. W.
72-73:020-121
Mendiratta, A. K.
72-73:050-001
Meyer, L. D.
72-73:02E-007
Michener, D. W.
72-73:020-216
72-73:020-220
72-73:05B-091
Middleton, J. E.
72-73:10A-001
Mielke, L. N.
72-73:058-018
Miles, D. L.
72-73:03F-052
Millar, A. A.
72-73:03F-028
Miller, D. A.
72-73:020-181
Miller, D. E.
72-73:020-026
72-73:03F-033
Miller, J. S.
72-73:02F-027
Miller, M.
72-73:03F-051
72-73:04A-082
Miller, R. J.
72-73:021-007
Milligan, T.
72-73:03F-053
72-73:03F-054
72-73:04A-049
72-73:G4A-050
72-73:04A-057
72-73:04A-053
72-73:04A-078
Millington, R. J.
72-73:03F-023
Milne, J.
72-73:04A-044
Mishra, G. C.
72-73:04A-004
72-73:04A-036
Miyamoto, S.
72-73:03A-001
Moe, D. L.
72-73:088-006
Moench, A. F.
72-73:02A-004
72-73:02F-007
72-73:02F-035
Molcho, M.
72-73:058-076
Moldenhauer, W. C.
72-73:040-002
Moline, W. J.
72-73:058-082
Molz, F. J.
72-73:020-071
Moncur, J. E. T.
72-73:04A-003
Monke, E. J.
72-73:020-158
Moraghan, J. T.
72-73:03F-027
Monkmeyer, P. L.
72-73:02F-072
Moore, C. V.
72-73:058-032
Moore, S. F.
72-73:050-011
Morel-Seytoux, H. J.
72-73:020-007
72-73:020-075
Morey, R. V.
72-73:020-213
72-73:04A-038
Morgan, D. L.
72-73:020-007
Morgan, N. W.
72-73:048-004
Morris, W. J.
72-73:048-004
Moschler, W. W.
72-73:020-178
Mualem, Y.
72-73:020-010
Muir, J.
72-73:058-005
72-73:058-064
Mulqueen, J.
72-73:020-019
Murray, W. A.
72-73:02F-072
Musgrave, W. F.
72-73:03F-004
Musick, J. T.
72-73:020-032
72-73:04A-069
Myers, L. E.
72-73:03F-042
72-73:04A-070
Nadler, A.
72-73:058-076
Nakayama, F. S.
72-73:020-023
72-73:020-025
72-73:02K-009
349
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Nalluswami, H.
72-73s05B-012
Naraken, L. N.
72-73:076-003
Naphade, J. D.
72-73:020-074
Naylor, D. W.
72-73:050-004
Nelson, D. W.
72-73:02E-011
72-73:020-143
72-73:021-006
72-73:02K-010
72-73:05A-002
72-73:058-051
Nelson, H. R., Jr.
72-73:03F-012
Nelson, L. B.
72-73:05B-047
Nelson, W. W.
72-73:020-185
Neuman, S. P.
72-73:02F-006
72-73:02F-020
72-73:02F-059
72-73:020-150
New, L.
72-73:04A-058
72-73:04A-081
Newton, J. P.
72-73:06A-004
Nicks, A. D.
72-73:04A-002
Nicol, K. J.
72-73:06D-002
Nielsen, D. R.
72-73:020-060
72-73:020-082
72-73:020-086
72-73:02K-004
Niraah, M. N.
72-73:020-110
72-73:020-111
Ninuner, G. L.
72-73:03F-067
Nir, D.
72-73:03F-014
Nixon, P. R.
72-73:02D-008
72-73:045-008
Noblanc, A.
72-73:020-007
Norero, A. L.
72-73:020-224
Norris, E. R.
72-73:020-171
Nunn, J. R.
72-73:020-031
O'Connell, P. F.
72-73:036-001
O'Donnell, T.
72-73:020-005
Ogata, G.
72-73:050-007
72-73:020-179
72-73:030-006
Ogut, C.
72-73:058-078
Olcott, P. G.
72-73:058-039
Olson, G. W.
72-73:08D-003
Olson, H. M.
72-73:020-208
Olson, R. A.
72-73:058-005
72-73:058-064
Olson, T. C.
72-73:02G-203
72-73:020-206
Onken, A. 8.
72-73:020-133
72-73:080-002
Onderdonk, J. J.
72-73:02J-013
Onstad, C. A.
72-73:02J-008
Oster, J. D.
72-73:020-108
72-73:020-117
72-73:02K-007
72-73:03F-001
72-73:03F-019
Overman, A. R.
72-73:020-042
Palta, J. P.
72-73:020-149
Pande, H. K.
72-73:02G-1&3
Pandya, A. C.
72-73:04A-021
Papadakis, C. N.
72-73:020-151
Papadopulos, S. S.
72-73:02F-019
72-73:02F-032
Papendick, R. I.
72-73:020-200
72-73:020-227
Paris, D. F.
72-73:050-001
Parker, J. J.
72-73:020-129
Parks, C. F.
72-73:03E-001
Parlange, J. Y.
72-73:020-025
72-73:020-034
72-73:020-090
72-73:020-093
Parmele, L. H.
"72-73:02D-004
72-73:02D-009
Parr, J. F.
72-73:058-046
Patrick, W. H., Jr.
72-73:020-098
Pawl us, M.
72-73:058-035
350
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Payne, L. F.
72-73:04A-023
72-73:10A-002
Pionke, H. B.
72-73:058-008
72-73:04A-002
Puttaswamygowda, B. S.
72-73:020-107
72-73:020-112
Peck, A. J.
72-73:020-095
72-73:02K-002
Perez, A. I.
72-73:05B-017
Perrens, S. J.
72-73:020-057
72-73:020-062
Perrier, E. R.
72-73:020-030
Perrine, R. L.
72-73:046-014
Peters, D. B.
72-73:03F-023
Peters, H. J.
72-73:02A-010
Peters, R. H.
72-73:058-087
Peterson, G. A.
72-73:020-121
Peterson, L. A.
72-73:020-180
Phene, C. J.
72-73:020-156
Philip, J. R.
72-73:020-078
Phillips, R. E.
72-73:056-071
Pickett, L. K.
72-73:021-002
Piest, R. F.
72-73:020-066
72-73:056-030
72-73:056-058
Pinder, G. F.
72-73:02F-002
72-73:02F-030
72-73:02F-032
72-73:02F-037
72-73:02F-074
Pohjakas, K.
72Ğ73:04A-043
Poland, J. F.
72-73:02F-001
Poostchi, I.
72-73:03F-026
Pope, D. L.
72-73:03F-068
Potter, A. L.
72-73:05D-006
Powell, G. M.
72-73:04A-068
Powell, R. D.
72-73:020-182
Power, J. F.
72-73:020-187
72-73:020-208
72-73:056-080
Powers, W. L.
72-73:02D-019
72-73:021-012
72-73:021-013
Pratt, P. F.
72-73:020-106
72-73:020-107
72-73:020-112
72-73:020-141
72-73:056-001
72-73:056-050
72-73:056-086
72-73:03F-015
Preston, H. A.
72-73:076-005
Preul, H. C.
72-73:020-151
Price, K. R.
72-73:02D-002
Prickett, T. A.
72-73:02F-007
Pruitt, W. O.
72-73:02D-007
72-73:06A-005
Pyatt, E. E.
72-73:056-017
Qazi, A.
72-73:046-007
Raats, P. A. C.
72-73:020-085
Radosevich, George E.
72-73:03F-016
Ragan, R. M.
72-73:02F-040
Ralston, D. S.
72-73:020-198
Rao, K. V. P.
72-73:020-183
Rapp, E.
72-73:020-173
Rasmussen, W. W.
72-73:020-134
Rausser, G. C.
72-73:066-001
Raveh, A.
72-73:056-063
Rawitz, E.
72-73:076-004
Rawlins, S. L.
72-73:020-116
72-73:030-009
Razmi, K.
72-73:03F-026
Reddy, A. S.
72-73:04A-004
Reeves, T. G.
72-73:050-014
Reginato, R. J.
72-73:02D-023
72-73:020-025
Rehm, G. W.
72-73:056-082
351
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Reichardt, K.
72-73:020-060
72-73:020-082
Reichman, G. A.
72-73:020-027
72-73:026-205
72-73:05B-080
Reicosky, D. C.
72-73:03F-023
Renger, M.
72-73:02P-076
72-73:020-009
Reynolds, W. N.
72-73:04A-071
72-73:04A-072
Rhoades, J. D.
72-73:020-021
72-73:040-001
Rhoads, F. M.
72-73:020-196
Rhue, R. D.
72-73:05B-081
Rice, C. E.
72-73:088-004
Richards, S. J.
72-73:02F-068
Richardson, A. J.
72-73:.10A-003
Richardson, C. W.
72-73:02E-004
Ritchie, J. T.
72-73:020-001
72-73:020-017
72-73:020-018
72-73:020-038
72-73:020-058
72-73:020-063
Robbins, C. W.
72-73:020-176
Roberts, S.
72-73:05B-077
Robertson, W. K.
72-73:020-199
72-73:03F-060
Robinson, D. L.
72-73:058-079
Robinson, F. E.
72-73:020-036
72-73:020-188
72-73:04A-066
72-73:03F-056
Rochester, E. W.
72-73:020-020
72-73:020-162
72-73:020-170
Rodarte, L.
72-73:02F-060
Rogowski, A. S.
72-73:02A-005
Romkens, N. J. M.
72-73:02E-011
72-73:05A-002
Rouse, J. V.
72-73:058-027
Rovers, F. A.
-72-73:058-092
Rubin, H.
72-73:02F-031
Rubin, J.
72-73:02F-017
72-73:058-021
Rushton, K. R.
72-73:048-012
Rutherford, R. J.
72-73:020-032
Ryan, J. F.
72-73:03A-001
72-73:05A-005
Saffer, M. J.
72-73:020-211
Saini, G. R.
72-73:026-190
Sandoval, F. M.
72-73:020-027
Sargunam, A.
72-73:02J-003
Sastry, G.
72-73:03F-008
72-73:04A-042
Sauer, V. B.
72-73:02E-002
Richardson, G. V.
72-73:020-008
Rightmire, C. T.
72-73:02K-005
Rijteroa, P. E.
72-73:020-169
Riley, J. P.
72-73:05B-016
72-73:048-004
Riley, P.
72-73:02J-003
Rosenberg, N. J.
72-73:020-010
72-73:020-194
Rosene, R. 8.
72-73:03E-001
Rouhani, I.
72-73:03F-026
Roulier, M. H.
72-73:02G-083
Rouquette, F. M., Jr.
72-73:058-041
72-73:058-042
Saxena, G. K.
72-73:026-199
72-73:03F-060
Schalscha, E. B.
72-73:020-141
Schertz, O. L.
72-73:020-181
Schicht, R. J.
72-73:048-001
Schickedanz, D. M.
72-73:080-002
Schild, N. W.
72-73-.03F-012
352
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Schillinger, G. R.
72-73:05B-027
Schiimnelpfennig, H.
72-73:020-193
Schlichting, E.
72-73:02G-024
Schmidt, K. D.
72-73:05B-006
Schneider, A. D.
72-73:04B-005
Scholl, D. G.
72-73:020-154
Schrader, L. E.
72-73:020-180
Schreiber, H. A.
72-73:10A-002
Schuman, G. E.
72-73:020-066
72-73:053-030
72-73:058-058
Schwab, G. C.
72-73:05B-091
Schwab, G. O.
72-73:020-216
72-73:020-220
Schwartz, F. W.
72-73:02K-003
Scott, H. D.
72-73:020-125
72-73:058-071
Seeborn, G. T.
72-73:03F-058
Seetharamiah, K.
72-73:04A-004
Seim, E. C.
72-73:058-005
72-73:058-064
Selim, H. M.
72-73:020-128
72-73:04A-035
Sellner, W. A.
72-73:020-208
Seniwongse, C.
72-73:04A-071
Settergrew, C. D.
72-73:05E-001
Sewell, J. I.
72-73:020-157
72-73:050-007
Shadid, O.
72-73:05D-002
Shafer, W. H., Jr.
72-73:058-027
Shalhevet, J.
72-73:020-041
Sharma, M. L.
72-73:02G-186
Shastry, J. S.
72-73:058-068
Shear, G. M.
72-73:020-178
Sheets, T. J.
72-73:020-068
72-73:058-004
72-73:058-065
Shen, H. W.
72-73:02J-011
Shepherd, W.
72-73:020-021
Shih, S. F.
72-73:02F-057
72-73:020-040
72-73:03F-065
Shindala, A.
72-73:050-005
Shimshi, D.
72-73:03F-020
Schoof, R. R.
72-73:04A-002
Shown, L. M.
72-73:020-005
Shull, H. H.
72-73:020-030
Shuster, E. T.
72-73:02F-013
Signer, D. C.
72-73:046-003
Singh, P.
72-73:020-046
72-73:04A-075
Singh, R. N.
72-73:058-011
72-73:020-228
Sionit, N.
72-73:030-004
Skaggs, R. W.
72-73:020-155
72-73:020-158
72-73:020-159
72-73:020-219
72-73:03F-013
Skogerboe, G. V.
72-73:056-001
72-73:06E-004
72-73:088-001
72-73:058-038
72-73:03F-016
72-73:04A-041
Sletten, W. H.
72-73:04A-069
Smajstria, A. G.
72-73:020-222
Small, G. G.
72-73:050-010
Smith, D. 'I.
72-73:02F-078
Smith, D. V.
72-73:03F-005
72-73:03F-017
Smith, E. F.
72-73:04A-017
Smith, J. H.
72-73:058-007
72-73:050-003
Smith, R. E.
72-73:02E-003
72-73:020-014
72-73:020-152
353
-------
Smith, S. J.
72-73:020-119
72-73:02G-148
Sneed, R. E.
72-73:03F-065
72-73:04A-047
Snyder, W. M.
72-73:02F-021
Soltani-Moharranadi, G. R.
72-73:020-073
72-73:04A-029
Somerhalder, B. R.
72-73:03F-064
72-73:04A-015
Sommerfeldt, T. G.
72-73:058-044
Sommers, L. E.
72-73:020-143
72-73:05B-051
72-73:021-006
Sorensen, R. C.
72-73:058-082
Soriano, A.
72-73:02F-075
72-73:02F-079
Soribe, F. I.
72-73:02F-062
Sowell, R. S.
72-73:03F-065
Spencer, B.
72-73:08B-005
Spencer, J. R.
72-73:02F-068
Spencer, W. F.
72-73:020-103
72-73:020-105
Spomer, R. G.
72-73:020-066
72-73:058-030
72-73:058-058
Stall, John B.
72-73:058-003
Stammers, W. N.
72-73:020-034
Stanford, G.
72-73:020-119
72-73:058-085
Stanley, R. L., Jr.
72-73:020-196
Stansell, J. R.
72-73:021-019
Steele, T. D.
72-73:058-013
Stevenson, F. J.
72-73:058-043
Stewart, J. I.
72-73:02D-011
72-73:020-069
72-73:06A-005
72-73:03F-010
72-73:03F-046
Stolzy, L. H.
72-73:020-083
72-73:03F-049
72-73:058-049
Stone, J. F.
72-73:020-079
72-73:020-081
Stone, L. R.
72-73:020-203
72-73:020-206
Strateener, G.
72-73:03F-020
Strebel, O.
72-73:02F-076
72-73:026-009
Streltsova, T. D.
72-73:02F-012
72-73:02F-048
72-73:02F-081
72-73:048-012
72-73:048-013
Strickland, J.
72-73:050-010
Stuart, D. M.
72-73:020-094
Stumm, W.
72-73:058-096
Subramanya, K.
72-73:020-004
72-73:04A-036
Sulaiman, W.
72-73:020-102
Sullivan, C. Y.
72-73:021-014
Sunada, D. K.
72-73:058-012
Swanson, U. P.
72-73:02E-012
Swartzendruber, D.
72-73:020-013
72-73:020-017
72--73:02G-113
72-73:04A-034
Szekelyhidi, I. J.
72-73:020-067
Tabatabai, M. A.
72-73:058-053
Takatori, F. H.
72-73:058-050
72-73:03F-015
Tanji, K. K.
72-73:020-002
72-73:020-109
72-73:03F-034
Taylor, H. M.
72-73:020-197
72-73:021-009
72-73:021-019
Teare, I. D.
72-73:020-193
Templer, O. W.
72-73:06E-005
Tenpas, G. H.
72-73:020-217
Thames, J. L.
72-73:026-061
Thomas, A. W.
72-73:020-131
Thomas, H. E.
72-73:048-020
354
-------
Thomas, J. L.
72-73:05B-016
Valantine, V. E.
72-73:030-002
Voisey, P. W.
72-73:02D-031
Thomas, J. R.
72-73:020-209
Valsangkar, A. J.
72-73-.02G-004
Volk, P. R.
72-73:04A-079
Thornes, J. B.
72-73:05B-019
Thornton, R. J.
72-73:05B-093
Threadgill, E. D.
72-73:02A-006
Timmons, D. R.
72-73:05B-075
van Bavel, C. H. M.
72-73:020-222
72-73:021-005
72-73:076-002
Van Denburgh, A. S.
72-73:02J-002
Van Doren, D. M., Jr.
72-73:020-137
72-73:04D-003
von Oettinger, S.
72-73:02D-007
Wahab, H. A.
72-73:03F-059
Waiss, A. C., Jr.
72-73:05D-006
Wakil, M.
72-73:020-118
Tischler, L. F.
72-73iOSB-015
Van Phuc, L.
72-73:020-075
Waldren, R. P.
72-73:020-193
Todsen, M.
72-73:020-168
Todd, R. M.
72-73:020-089
Tomar, U. S.
72-73:021-008
Torres B., Carlos
72-73:020-130
Triplett, G. B., Jr.
72-73:020-137
72-73:02J-014
Tsang, G.
72-73:08B-007
Tseng, M. T.
72-73:02F-040
Tucker,J. M.
72-73:040-001
Turner, A. K.
72-73:04A-028
Twitchell, G. A.
72-73:020-031
tr.,1, v. w.
72-73:04A-009
Unger, P. W.
72-73:026-129
Vachaud, G.
72-73:02G-118
Van Schaik, J. C.
72-73:020-173
Van Schilfgaarde, J.
72-73:060-001
Varade, S. B.
72-73:020-183
Varlev, I.
72-73:04A-039
Varney, K. E.
72-73:05B-048
Vauchlin, M.
72-73:020-118
Vazari, C. M.
72-73:020-221
72-73:04A-072
Verruijt, A.
72-73:02F-010
Vincent, G. B.
72-73:03F-030
Vitosh, M. L.
72-73:020-065
72-73:058-057
Vittetoe, G.
72-73:03F-003
Vlachos, E. C.
72-73:03F-016
Waldron, A. C.
72-73:020-220
72-73:058-091
Walker, H. J.
72-73:020-001
Walker, W. G.
72-73:05B-039
72-73:053-040
Walker, Wynn R.
72-73:06E-004
72-73:088-001
72-73:056-038
72-73:04A-041
Walker, William R.
72-73:06E-002
Wallihan, E. F.
72-73:020-112
72-73:021-016
Walter, C. L.
72-73:088-011
Wang, B-H
72-73:04B-004
Ward, R. C.
72-73:06E-004
Warncke, D. D.
72-73:020-018
72-73:020-020
Warkentin, B. P.
72-73:020-100
355
-------
Warrick, A. W.
72-73:02F-080
72-73:020-061
72-73:020-139
Watson, K. K.
72-73:020-057
72-73:020-062
72-73:020-080
Webb, J. R.
72-73:020-182
Weber, E. M.
72-73:02A-008
Weeks, L. U.
72-73:020-083
Wein, R. W.
72-73:020-056
Weisbrod, M.
72-73:03F-020
Welch, N. H.
72-73:02J-004
Wentink, G. R.
72-73:05A-004
Wesseling, J.
72-73:020-117
West, N.
72-73:020-056
Westerman, R. L.
72-73:020-132
72-73:020-135
72-73:056-072
72-73:020-226
Whinston, A. B.
72-73:050-004
Whisler, F. D.
72-73:020-057
72-73:020-062
72-73:020-080
Whitaker, R. J.
72-73:02F-078
White, A. W.
72-73:05B-036
White, E. M.
72-73:058-045
72-73:058-056
White, L. M.
72-73:02D-013
White, R. K.
72-73:020-220
72-73:058-091
White, W. A.
72-73:058-015
White, W. B.
72-73:02F-013
Whiteley, H. R.
72-73:02D-034
Wiegand, C. L.
72-73:078-003
Wilke, O. C.
72-73:03F-047
Wilkins, D. C.
72-73:080001
Willardson, L. S.
72-73:02F-068
72-73:02F-071
72-73:05F-003
72- 73:03F-001
72-73:03F-009
72-73:03F-019
Williams, J. R.
72-73:070-001
72-73:02J-005
Williams, R. A.
72-73:050-002
72-73:048-006
Williams, R. J. B.
72-73:058-095
Williamson, E. J.
72-73:058-056
Willis, C.
72-73:068-001
Willis, G. H.
72-73:058-062
Willis, W. O.
72-73:020-187
Wilmouth, R. R.
72-73:020-178
Wilson, J. L.
72-73:02F-027
Wilson, L.
72-73:02J-001
Wianant, W. M.
72-73:078-005
Wind, G. P.
72-73:020-015
Wirth, M. E.
72-73:056-089
Witherspoon, P. A.
72-73:02F-006
Wittmuss, H. D.
72-73:02J-014
Wolanski, E. J.
72-73:02F-028
Wolff, R. G.
72-73:02F-019
Wood, W. W.
72-73:026-008
Wooding, R. A.
72-73:02F-028
72-73:02F-045
72-73:02F-047
72-73:058-025
Woody, W. M.
72-73:020-200
Wright, J. L.
72-73:02D-006
Wright, R. S.
72-73:05A-001
Wrightington, R.
72-73:050-003
Wu, I-pai
72-73:02E-008
72-73:04A-071
72-73:04A-073
72-73:03F-007
Yamada, H.
72-73:021-007
Yang, S. J.
72-73:03F-029
356
-------
Yao, K. M.
72-73:05D-011
Yaron,' D.
72-73:020-041
72-73:03C-001
Yeh, W. W-G.
72-73:02F-025
72-73:02F-050
72-73:02P-082
Yen, B. C.
72-73:02F-005
Yermanos, D. M.
72-73:020-144
72-73:030-007
Young, E. C.
72-73:04A-032
Young, L. L.
72-73:058-034
Young, R. A.
72-73:04B-010
7<3-73:02J-009
Young, R. H. F.
72-73:05B-088
Young, T. C.
72-73:020-043
Yousif, Y. H.
72-73:020-144
72-73:030-007
Yu, W.
72-73:050-012
Zachmann, D. W.
72-73:020-131
Zanker, A.
72-73:02K-011
Zimmermann, U.
72-73:020-024
Zube, E. H.
72-73:06D-003
Zwerman, P. J.
72-73:05B-029
Zytynski, M.
72-73:02F-046
357
-------
Section XXXXIII
Absorption
72-73:02F-004
72-73:020-100
72-73:026-169
72-73:03F-003
72-73:03F-023
72-73:05B-092
72-73:050-010
Abstracts
72-73:05G-013
Acidity
72-73:020-101
Acreage
72-73:03F-006
72-73:03F-021
Activated Carbon
72-73:050-014
Activated Sludge
72-73:05D-009
72-73:050-014
Adaptation
72-73:03F-030
72-73:03F-031
Adjudication Procedure
72-73:06E-001
Administration
72-73:03F-016
Adsorption
72-73:02F-047
72-73:020-001
72-73:020-016
72-73:020-018
72-73:020-020
72-73:020-023
72-73:020-058
72-73:020-086
72-73:020-099
72-73:020-100
72-73:020-126
72-73:020-127
72-73:05B-022
72-73:058-024
72-73:058-030
72-73:058-059
72-73:058-069
72-73:050-001
SUBJECT INDEX
Advection
72-73:020-006
72-73:020-008
72-73:020-010
72-73:020-016
Aerobic Bacteria
72-73:05C-001
Aerobic Conditions
72-73:020-103
72-73:020-105
72-73:020-107
72-73:05C-001
Agricultural Chemicals
72-73:058-024
72-73:058-047
72-73:058-062
72-73:058-091
Agricultural Engineering
72-73:020-020
72-73:020-032
72-73:020-041
72-73:03F-002
72-73:03F-013
72-73:03F-051
72-73:03F-052
72-73:04A-007
72-73:04A-008
72-73:04A-009
72-73:04A-017
Agricultural Runoff
72-73:02E-013
72-73:02J-008
72-73:03F-047
72-73:03F-068
72-73:058-029
72-73:058-052
72-73:056-056
72-73:058-095
72-73:058-096
72-73:050-007
Agricultural Watersheds
72-73:02E-013
72-73:058-036
Agriculture
72-73:02F-073
72-73:03C-002
72-73:03C-003
72-73:03C-008
Agriculture (Cont.)
72-73:03F-014
72-73:03F-017
72-73:03F-018
72-73:03F-046
72-73:058-029
72-73:060-001
72-73:060-002
72-73:06E-004
Agronomic Crops
72-73:020-010
72-73:03C-004
Agronomy
72-73:03F-065
72-73:03F-067
72-73:078-002
Air
72-73:050-010
Air Pollution
72-73:030-005
72-73:030-006
72-73:030-009
Air Pollution Effects
72-73:030-005
72-73:030-009
Air-Earth Interfaces
72-73:020-023
72-73:020-024
Alaska
72-73:020-001
Albedo
72-73:03F-024
Aldrin
72-73:050-010
Alfalfa
72-73:020-006
72-73:020-010
72-73:020-145
72-73:020-181
72-73:021-010
72-73 :03F-025
72-73:04A-052
72-73:04A-053
72-73:05C-008
358
-------
Algae
72-73:050-001
72-73:050-002
Algorithms
72-73:04B-009
Alkali Soils
72-73:020-107
72-73:020-144
Alkaline Soils
72-73:020-112
72-73:03A-001
Alkaline Water
72-73:03A-001
Alkalinity
72-73:03A-001
Alluvial Aquifers
72-73:02D-014
72-73:02D-015
Alluvial Channels
72-73:02D-014
72-73:02D-015
72-73:02F-053
72-73:04A-004
72-73:08B-002
72-73:08B-003
Alluvium
72-73:048-007
72-73:05B-006
Alternative Planning
72-73:03F-018
72-73:06A-003
Aluminum
72-73:03F-051
Ammonia
72-73:020-200
72-73:05B-029
Anabaena
72-73:050-002
Anaerobic Bacteria
72-73:05C-001
72-73:05F-003
Anaerobic Conditions
72-73:020-098
72-73:020-103
72-73:020-105
72-73:020-107
Anaerobic Conditions
(Cont.)
72-73:05C-001
Analog Computers
72-73:020-147
72-73:04B-004
Analog Models
72-73:04A-032
Analysis
72-73:03F-034
Analytical Techniques
72-73:020-007
72-73:020-096
72-73:03F-002
72-73:04B-001
72-73:05B-061
72-73:076-002
Animal Wastes (Wildlife)
72-73:05B-057
72-73:056-086
72-73:058-095
72-73:058-096
Anisotropy
72-73:02F-052
72-73:02F-059
72-73:020-003
72-73:-2G-025
72-73:04A-004
Antecedent Precipitation
72-73:020-151
72-73:020-152
Application Equipment
72-73:020-175
72-73:04A-020
72-73:04A-044
72-73:04A-047
72-73:04A-048
72-73:04A-050
72-73:04A-051
72-73:04A-052
72-73:04A-055
72-73:04A-056
72-73:04A-057
72-73:04A-058
72-73:04A-059
72-73:04A-061
72-73:04A-062
72-73:04A-070
72-73:04A-074
72-73:04A-076
72-73:04A-081
Application Methods
72-73:020-101
72-73:03F-066
72-73:04A-007
72-73:04A-020
72-73:04A-079
72-73:04A-081
72-73:088-006
Appropriation
72-73:06E-001
72-73:06E-002
Aquatic Environment
72-73:05C-001
72-73:050-011
Aquatic Microorganisms
72-73:050-001
Aquatic Plants
72-73:05B-008
Aquatic Productivity
72-73:05C-001
72-73:05C-002
Aquatic Soils
72-73:058-008
72-73:050-002
Aqueous Solutions
72-73:02F-045
72-73:020-002
72-73:020-018
72-73:020-020
72-73:020-036
72-73:020-061
72-73:020-077
72-73:020-089
72-73:02K-009
Aquicludes
72-73:02F-019
72-73:02F-060
72-73:020-128
Aquiculture
72-73:058-089
Aquifer characteristics
72-73:02F-002
72-73:02F-009
72-73 :02F-014
72-73:02F-025
72-73:02F-044
72-73:02F-060
72-73:02F-079
72-73:048-001
72-73:048-006
359
-------
Aquifer Characteristics
(Cent.)
72-73:05B-018
Aauifer Management
72-73:02A-008
72-73:02A-010
72-73:02F-066
Aquifer Systems
72-73:02F-007
72-73:02F-008
72-73:02F-083
Aquifer Testing
72-73:02F-004
72-73:02F-006
72-73:02F-008
72-73:02F-029
72-73:02F-036
72-73:02F-037
72-73:02F-044
72-73:02F-049
72-73:02F-052
72-73:04B-006
72-73:04B-011
72-73:04B-012
72-73:046-013
Aquifers
72-73:02F-031
72-73:02F-059
72-73:02F-066
72-73:02F-072
72-73:02F-079
72-73:02F-081
72-73:02F-082
72-73:02F-083
72-73:048-002
72-73:04B-009
72-73:06E-003
Aquitards
72-73:02F-006
72-73:02F-008
72-73:02F-019
72-73:02F-052
Arctic
72-73:02C-001
Areal Hydrogeology
72-73:02F-083
Arid Climates
72-73:02D-028
72-73:02D-029
72-73:03C-008
72-73:03F-056
Arid Lands
72-73:020-002
72-73:020-006
72-73:03F-002
72-73:04A-085
72-73:046-008
72-73:043-030
Arizona
72-73:03B-001
72-73:048-020
72-73:056-006
Arroyos
72-73:02E-003
Artesian Aquifers
72-73:02F-003
72-73:02F-006
72-73:02F-007
72-73:02F-008
72-73:02F-019
72-73:02F-025
72-73:02F-030
72-73:04B-006
72-73:048-011
72-73:048-015
Artesian Heads
72-73:02F-007
Artesian Wells
72-73:048-015
Artificial Precipitation
72-73:02J-009
Artificial Recharge
72-73:02F-001
72-73:02F-027
72-73:02F-050
72-73:02F-066
72-73:048-003
72-73:048-009
72-73:048-016
72-73:060-001
Asparagus
72-73:058-050
Asphalt
72-73:02G-033
72-73:020-199
72-73:03F-060
Australia
72-73:02F-042
72-73:02F-043
72-73:02K-002
72-73:04A-045
Automatic Control
72-73:02E-012
72-73:020-156
72-73:03F-064
72-73:04A-043
72-73:04A-063
Automation
72-73:020-222
72-73:03F-057
72-73:04A-009
72-73:04A-043
72-73:04A-056
72-73:04A-057
72-73:05A-005
72-73:078-001
Available Water
72-73:02F-076
72-73:020-026
Bacteria
72-73:058-007
72-73:05C-002
Balance of Nature
72-73:058-008
Barley
72-73:020-122
72-73:020-205
72-73:020-208
72-73:03F-066
Barometric Efficiency
72-73:02F-008
Barriers
72-73:020-183
72-73:020-199
Basalts
72-73:02F-044
72-73:050-002
Base Flow
72-73:02A-001
72-73:02A-004
72-73:02A-010
72-73:020-037
72-73:04A-002
72-73:048-007
72-73:058-017
Beans
72-73:03C-005
72-73:03C-009
72-73:03F-028
360
-------
Bed Load
72-73:02E-012
72-73:02J-007
72-73:02,1-011
Bed Load Samplers
72-73:02E-012
Beneficial Use
72-73:06E-002
Benefits
72-73:03F-006
72-73:03F-021
72-73:050-003
Benthos
72-73:050-001
Bibliographies
72-73:03F-034
72-73:03F-063
72-73:03F-067
72-73:05G-013
Bica rbonates
72-73:056-016
72-73:056-027
72-73:050-001
Biochemical Oxygen Demand
72-73:04A-003
72-73:056-010
72-73:058-068
72-73:050-003
72-73:05D-001
72-73:050-002
72-73:056-004
72-73:056-012
Biodegradation
72-73:058-039
72-73:056-040
72-73:050-001
Bioindicators
72-73:026-067
72-73:050-001
Biological Communities
72-73:026-067
Biological Treatment
72-73:05D-014
Biomass
72-73:050-002
eiorhythms
72-73:026-067
Bodies of Water
72-73:02F-083
Border Irrigation
72-73:02E-008
72-73:026-034
72-73:026-064
72-73:026-223
72-73:04A-007
72-73:04A-008
72-73:04A-039
72-73 :04A-043
Boreholes
72-73:02F-049
Boron
72-73:026-102
72-73:026-122
72-73:026-144
72-73:03F-034
72-73:05A-005
Bottom Sediments
72-73:050-001
Boundary Layers
72-73:02F-028
Brines
72-73:026-087
72-73:04B-002
Brush Control
72-73:046-008
Bulk Density
72-73:026-056
72-73:026-084
72-73:026-100
72-73:026-104
72-73:026-129
Cadmium
72-73:02K-001
Calcareous Soils
72-73:026-094
Calcium
72-73:026-145
72-73:02J-003
72-73:03F-025
72-73:05B-016
72-73:050-009
72-73:056-045(Page 291
Calcium Carbonate
72-73:026-094
72-73:056-083
Calibrations
72-73:02F-014
72-73:02F-017
72-73:026-079
72-73:026-081
72-73:026-084
72-73:026-092
72-73:026-104
72-73:026-117
72-73:02J-004
Caliche
72-73:026-094
California
72-73;
72-73:
72-73:
72-73:
72-73:
72-73;
72-73:
72-73;
72-73:
72-73:
72-73:
72-73:
72-73:
02D-007
;02D-008
:03F-001
:03F-011
;03F-015
03F-019
03F-034
03F-056
03F-066
: 046-008
;04B-020
05B-068
:06A-002
Canada
72-73:020-016
72-73:02F-038
72-73:02K-003
72-73:056-046
Canal Design
72-73:02J-007
72-73:04A-036
Canal Linings
72-73:04A-036
72-73:04A-040
Canal Seepage
72-73:04A-006
72-73:04A-032
72-73:04A-036
72-73:046-016
72-73:086-002
Canals
72-73:02J-007
72-73:03F-005
72-73:03F-039
72-73:04A-036
72-73:056-003
Capillary Action
72-73:02F-016
72-73:02F-061
361
-------
Capillary Action
(Cont.}
72-73:020-007
72-73:026-010
Capillary Conductivity
72-73:02F-016
72-73:02G-007
72-73:020-010
72-73:020-015
72-73:020-037
Capillary Fringe
72-73:03F-023
72-73:04B-012
72-73:048-013
Capillary Water
72-73:04B-012
72-73:04B-013
Carbamate Pesticides
72-73t05C-010
Carbon
72-73:02K-005
72-73:05C-001
Carbon Cycle
72-73:05C-001
Carbon Dioxide
72-73:02F-013
72-73:05C-001
Carbon Filters
72-73:050-009
Carbonate Rocks
72-73:02F-013
72-73:02K-006
Carbonates
72-73:02K-001
72-73:05C-001
Carp
72-73:053-089
Carrying Capacity
72-73:04A-015
Catfishes
72-73:05B-089
Cation Adsorption
72-73:020-001
72-73:020-016
72-73:05D-006
Cation Exchange
72-73:020-021
72-73:020-099
72-73:020-138
72-73:020-141
72-73:020-147
72-73:05A-004
72-73:05B-083
Cations
72-73:020-147
Cattle
72-73:03F-025
72-73:05B-018
72-73:053-095
Caves
72-73:02F-041
Cellulose
72-73I03F-025
Channel Erosion
72-73:088-003
Channels
72-73:02E-003
72-73:02J-007
72-73:03F-011
Chaparral
72-73:048-008
Chelation
72-73:020-140
72-73:05D-006
Chemcontrol
72-73:02D-032
Chemical Analysis
72-73:05A-005
Chemical Degradation
72-73:058-010
Chemical Oxygen Demand
72-73:050-010
Chemical Potential
72-73:020-077
Chemical Precipitation
72-73:020-025
72-73:02F-047
72-73:058-083
72-73:058-093
72-73:050-014
Chemical Properties
72-73:020-144
72-73:02K-009
Chemical Reactions
72-73:02F-045
72-73:05A-005
72-73:058-021
Chemicals
72-73:020-055
Chlorides
72-73:020-025
72-73:020-019
72-73:020-058
72-73:020-086
72-73:02J-003
72-73:02K-002
72-73:02K-004
72-73:03C-007
72-73:058-016
72-73:058-027
Chlorinated Hydrocarbon
Pesticides
72-73:058-004
72-73:05C-010
Chlorination
72-73:050-013
72-73:050-014
Chlorophyll
72-73:021-016
72-73:021-017
Chromatography
72-73:02F-045
Chromium
72-73:02F-074
72-73:05A-004
Citrus Fruits
72-73:021-016
Clay Minerals
72-73:020-016
72-73:020-021
72-73:05C-001
Clays
72-73:020-001
72-73:020-023
72-73:020-099
72-73:020-100
72-73:020-125
72-73:020-138
72-73:05A-004
362
-------
Cleaning
72-73:04A-005
Clear-Cutting
72-73:038-001
72-73:04A-030
Climates
72-73:02D-002
72-73:020-014
72-73:02D-015
72-73:02D-017
72-73:02D-018
72-73:02D-033
72-73:02F-038
72-73:02J-006
72-73:03F-046
72-73:03F-067
Climatic Data
72-73:02A-006
72-73:02D-006
72-73:020-008
72-73:020-027
72-73:03F-014
Climatology
72-73:020-007
72-73:020-016
72-73:02J-001
72-73:02K-005
Clogging
72-73:04A-005
Closed Conduits
72-73:02F-062
72-73:020-043
72-73:083-006
72-73:083-007
Cloud Cover
72-73:021-019
Clouds
72-73:021-019
Coagulation
72-73:058-093
Coastal Bermudagrass
72-73:053-041
72-73:053-042
Coastal Plains
72-73:02F-021
Coasts
72-73:020-008
Cohesive Soils
72-73:02J-003
Cold Springs
72-73:02F-077
Coliforms
72-73:053-006
72-73:053-007
72-73 :05C-003
Colorado
72-73:020-005
72-73:03F-025
72-73:043-007
72-73:053-038
Colorado River
72-73:02E-014
72-73:053-027
72-73:053-038
Colorado River Basin
72-73:02E-014
72-73:020-056
72-73:050-016
Columbia River
72-73:04A-003
Compaction
72-73:02F-036
Comparative Costs
72-73:05A-029
Competing Uses
72-73:06E-002
Compressibility
72-73:02F-018
72-73:02F-020
Computer Models
72-73:02A-006
72-73:02A-007
72-73:02A-008
72-73:020-020
72-73:02E-013
72-73:02F-066
72-73:02F-081
72-73:02F-082
72-73:020-043
72-73:020-067
72-73:020-071
72-73:020-110
72-73:020-111
72-73:020-126
72-73:020-147
72-73:020-150
Computer
(Cont
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
Models
73:020-155
73:020-167
73:020-168
73:020-194
73:020-211
73:020-213
73:020-222
73:021-002
73:021-004
73:021-012
73:021-018
73:03C-001
73:03F-020
73:03F-034
73:03F-067
73:04A-007
73:04A-008
73:04A-012
73:04A-020
73:04A-025
73:04A-029
73:04A-038
73:04A-049
73:048-004
73:040-004
73:050-016
Computer Programs
72-73:020-027
72-73:02F-057
72-73:020-017
72-73:020-083
72-73:020-152
72-73:03F-065
72-73:04A-017
72-73:043-004
72-73:04B-015
72-73:056-015
72-73:058-016
72-73:058-068
72-73S06A-003
72-73:070-001
Computers
72-73:02F-057
72-73:020-067
72-73:03F-008
72-73:03F-013
72-73:068-001
Conductivity
72-73:020-002
72-73:020-059
Confined Water
72-73:02F-001
72-73:02F-006
72-73:02F-007
363
-------
Confined Water
(Cont.)
72-73:02F-008
72-73:02F-019
72-73:02F-081
72-73:02F-082
72-73:020-004
72-73:04B-001
72-73:04B-006
72-73:04B-011
72-73:06D-001
Confinement Pens
72-73:05B-067
Conjunctive Use
72-73:048-004
72-73:048-005
72-73:048-007
72-73:048-010
72-73:048-020
72-73:058-017
Conservation
72-73:03F-055
72-73:066-001
Consolidation
72-73:02F-036
Constraints
72-73:03F-016
72-73:06A-004
Construction
72-73:020-171
72-73:088-011
Consumptive Use
72-73:02D-001
72-73:02D-005
72-73:02D-013
72-73:020-020
72-73:02D-021
72-73:02D-028
72-73:020-029
72-73:020-031
72-73:020-032
72-73:020-047
72-73:020-153
72-73:021-009
72-73:03F-025
72-73:03F-027
72-73:03F-030
72-73:03F-031
72-73:03F-063
72-73:03F-064
72-73:03F-065
Control
72-73:021-011
Controlled Drainage
72-73:06E-001
Convection
72-73:02E-001
72-73:02F-027
72-73:02F-031
72-73:02F-034
72-73:020-036
72-73:020-089
72-73:02K-004
72-73:058-012
Coolants
72-73:020-033
Copper
72-73:05A-004
72-73:05C-010
Copper Sulfate
72-73:05C-010
Core Drilling
72-73:08C-002
Cores
72-73:020-083
72-73:08C-002
Corn
72.
72
72-
72.
72
72.
72
72.
72
72
72.
72
72
72.
72
72
72.
72
72-
72
72
72
-73:020-037
-73:020-038
73:020-137
-73:020-142
-73:020-153
-73:020-174
-73:020-178
-73:020-180
-73:020-182
-73:020-199
-73:020-208
-73:020-228
-73:021-002
-73:021-009
-73:021-018
-73:02J-013
73:03F-061
-73:04A-052
73:04A-079
-73:058-078
-73:058-079
-73:10A-003
Corn (Field)
72-73:03F-030
Corn (Field)
(Cont.)
72-73:03F-064
72-73:058-036
Correlation Analysis
72-73:058-013
72-73:058-019
Cost Analysis
72-73:03F-007
72-73:050-012
Cost-Benefit Analysis
72-73:020-067
72-73:06A-001
Cost-Benefit Ratio
72-73:020-047
Cost Sharing
72-73:050-003
Costs
72-73203F-004
72-73:03F-057
72-73:03F-068
72-73:050-002
72-73:050-011
72-73:068-001
72-73:060-001
Cotton
72-73:020-184
72-73:020-192
72-73:020-197
72-73:020-201
72-73:020-204
72-73:021-004
72-73:021-007
72-73:03F-062
72-73:04A-066
72-73:05C-009
72-73:10A-003
Cracks
72-73:020-063
Crop Production
72-73:020-013
72-73:020-037
72-73:020-027
72-73:020-041
72-73:020-106
72-73:020-130
72-73:020-133
72-73:020-179
72-73:020-181
72-73:020-182
364
-------
Crop Production
(Cont.)
72-73:020-183
72-73:020-188
72-73:020-189
72-73:020-195
72-73:020-201
72-73:020-226
72-73:021-002
72-73:021-003
72-73:021-004
72-73:021-008
72-73:03P-002
72-73:03F-007
72-73:03F-023
72-73:03F-025
72-73:03F-026
72-73:03F-027
72-73:03F-030
72-73:03F-031
72-73:03F-046
72-73:03F-053
72-73:03F-055
72-73:03F-056
72-73:03F-063
72-73:03F-064
72-73:03F-065
72-73:03F-066
72-73:04A-007
72-73:04A-015
72-73:04A-018
72-73:04A-020
72-73:04A-053
72-73:053-072
72-73:058-077
72-73:053-078
72-73:053-079
72-73:07M-002
Crop Response
72-73:02D-006
72-73:02D-010
72-73:023-001
72-73:02D-037
72-73:02D-038
72-73:020-041
72-73:020-106
72-73:020-122
72-73:020-130
72-73:020-133
72-73:020-135
72-73:020-145
72-73:020-153
72-73:020-156
72-73:026-159
72-73:020-163
72-73:020-166
72-73:020-172
72-73:020-174
Crop Response
(Cont.)
72-73:020-175
72-73:020-179
72-73:020-180
72-73:020-181
72-73:020-182
72-73:020-183
72-73:020-185
72-73:020-187
72-73:020-188
72-73:020-189
72-73:020-191
72-73:020-192
72-73:020-195
72-73:020-196
72-73:020-197
72-73:020-198
72-73:020-199
72-73:020-201
72-73:020-202
72-73:020-204
72-73:-2G-207
72-73:020-209
72-73:020-213
72-73:020-216
72-73:020-217
72-73:020-218
72-73:020-219
72-73:020-226
72-73:020-228
72-73:021-002
72-73:021-003
72-73:021-006
72-73:021-007
72-73:021-008
72-73:021-010
72-73:021-011
72-73:021-018
72-73:03C-004
72-73:03C-007
72-73:03F-010
72-73:03F-030
72-73:03F-052
72-73:03F-053
72-73:03F-055
72-73:03F-062
72-73:03F-063
72-73:03F-065
72-73:03F-071
72-73:03F-072
72-73:03F-073
72-73:04A-053
72-73:04A-066
72-73:04A-078
72-73:04A-079
72-73:04A-080
72-73:053-072
72-73:053-077
Crop Response
(Cont.)
72-73:053-078
72-73:053-079
72-73:053-080
72-73:05C-008
72-73:05C-009
72-73:073-002
Crops
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
73:02D-008
73:020-130
'73:020-133
73:020-226
73:03F-003
73:03F-013
73:03F-014
73:03F-015
73:03F-018
73:03F-020
73:03F-021
-73:03F-024
73:03F-065
73:03F-067
73:053-072
73:06D-002
Cultivation
72-73:020-037
72-73:02E-011
72-73:020-027
72-73:020-039
72-73:020-129
72-73:020-136
72-73:020-137
72-73:020-178
72-73:020-192
72-73:020-227
72-73:02J-008
72-73:02J-014
72-73:03F-055
72-73:053-060
72-73:08C-001
Culverts
72-73:04A-041
Currents (Water)
72-73:02E-001
72-73:053-010
Cyanophyta
72-73:05C-002
Cycling Nutrients
72-73:053-096
72-73:05C-001
72-73:05C-002
365
-------
Dairy Industry
72-73:053-086
72-73:05D-007
Damages
72-73:030002
Dams
72-73:06A-004
Darcys Law
72-73:020-003
72-73:020-037
72-73:020-040
72-73:020-071
72-73:04A-006
Data Collections
72-73:02F-051
72-73:02J-001
72-73:02j-002
72-73:03F-002
72-73:050-011
72-73:073-005
72-73:10A-002
Data Processing
72-73:020-003
72-73:020-027
72-73 :02P-051
72-73:07B-005
Data Storage and Retrieval
72-73:03F-067
72-73:076-005
72-73:10A-002
Data Transmission
72-73:073-005
Deep Percolation
(Cont.)
72-73:03F-060
72-73:050-010
Deep Tillage
72-73:020-027
72-73:020-134
72-73:080-001
Defoliants
72-73:053-065
Deformation
72-73:02F-036
72-73:02F-058
72-73:083-011
Degradation (Decomposition)
72-73:05C-001
Deicers
72-73:053-014
Depth
72-73:020-029
Desalination
72-73:063-001
Desert Plants
72-73:020-056
Deserts
72-73:020-056
Design
72-73:03F-003
72-73:03F-021
72-73:03F-039
72-73:050-011
Design Criteria
72-73:03F-003
72-73:03P-064
72-73:083-001
Desilting
72-73:02J-007
Delaware River
72-73:06A-003
Detergents
Delaware River Basin Commission 72-73:05A-005
72-73:050-004 72-73:053-096
Dates
DDT
72-73:03F-031
72-73:050-010
Decision Making
72-73:02F-059
72-73:03F-004
72-73:03F-006
72-73:03F-018
72-73:03F-020
72-73:03F-021
72-73:040-001
72-73:06A-004
72-73:063-001
Deep Percolation
72-73:020-033
72-73:020-203
Denitrification
72-73:020-106
72-73:020-226
72-73:02H-001
72-73:03F-015
72-73:053-001
72-73:053-002
72-73:053-048
72-73:053-049
72-73:053-050
72-73:053-063
72-73:053-084
72-73:053-085
72-73:05C-002
72-73:050-005
72-73:050-009
72-73:050-010
72-73:050-012
72-73:050-014
72-73:05F-003
Density
72-73:02F-022
72-73:020-079
Density Stratification
72-73:02F-027
72-73:02F-031
72-73:053-014
Deterioration
72-73:04A-040
Dieldrin
72-73:05C-010
Diffusion
72-73:02E-001
72-73:02F-016
72-73:02F-028
72-73:02F-034
72-73:02F-035
72-73:02F-036
72-73:02F-045
72-73:02F-047
72-73:020-018
72-73:020-020
72-73:020-082
72-73:020-086
72-73:020-087
72-73:020-089
72-73:020-090
72-73:020-093
72-73:020-102
72-73:020-117
'72-73 :02K-004
72-73:053-011
72-73:053-012
72-73:053-025
72-73:053-026
366
-------
Diffusion
(Cont.)
72-73:05B-071
Diffusivity
72-73;
72-73:
72-73:
72-73;
72-73;
72-73:
72-73;
72-73:
72-73i
72-73:
72-73:
72-73:
72-73:
72-73:
02A-004
02D-024
02F-019
02G-011
02G-017
02G-060
02G-082
02G-089
02G-090
02G-093
02G-100
02G-117
02G-146
05B-026
Digestion
72-73:021-006
72-73:03F-025
72-73:05B-051
Digital Computers
72-73-.03F-014
72-73:04B-004
72-73:056-002
72-73:06A-003
Dimensional Analysis
72-73:02F-050
72-73:03F-008
Discharge (Water)
72-73:02A-003
72-73:02A-004
72-73:02C-001
72-73:02F-011
72-73:02F-038
72-73:02F-042
72-73:05G-003
72-73:060-001
Discharge Coefficient
72-73:088-001
Discharge Measurement
72-73:02C-001
72-73:088-001
Dispersion
72-73:02F-004
72-73:02F-017
72-73:02F-026
72-73:02F-027
72-73:02F-028
72-73:02F-031
72-73:02F-034
Dispersion
(Cont.)
72-73:02F-036
72-73:02F-045
72-73:026-001
72- 73:020-023
72-73:020-036
72-73:020-055
72-73:020-058
72-73:020-061
72-73:020-086
72-73:020-089
72-73:02J-011
72-73:02K-004
72-73:058-010
72-73:058-012
72-73:05B-021
72-73:058-022
72-73:058-026
72-73:053-058
72-73:058-059
Dissolved Oxygen
72-73:04A-003
72-73:058-010
72-73:05B-068
72-73:05C-002
72-73:05C-003
72-73:05D-001
72-73:050-002
72-73:050-004
Dissolved Solids
72-73:02J-002
72-73:03C-002
Distillation
72-73:050-014
Distribution
72-73:03F-014
72-73:050-001
Distribution Patterns
72-73:020-009
72-73:020-013
72-73:03F-002
Distribution Systems
72-73:020-163
72-73:03F-011
72-73:03F-042
72-73:03F-057
72-73s04A-009
72-73:04A-023
72-73:04A-025
72-73:04A-047
72-73:04A-048
72-73:04A-050
72-73:04A-058
Distribution Systems
(Cont.)
72-73:04A-059
72-73:04A-060
Ditches
72-73:02G-128
72-73:03F-011
72-73:04A-033
Diurnal
72-73:020-014
72-73:020-015
72-73:020-025
72-73:026-197
Diversion
72-73:04A-003
Diversion Structures
72-73:02J-007
72-73:06A-004
Dolomite
72-73:02F-013
Domestic Water
72-73:058-088
Douglas Fir Trees
72-73:04A-030
Drainage
72-73:02F-068
72-73:02F-069
72-73:02F-071
72-73:02F-075
72-73-.02F-079
72-73:026-015
72-73:026-026
72-73:026-030
72-73:026-040
72-73:026-042
72-73:026-043
72-73:026-071
72-73:026-072
72-73:026-080
72-73:026-095
72-73:026-103
72-73:026-105
72-73:026-106
72-73:026-110
72-73:026-111
72-73:026-112
72-73:026-118
72-73:026-139
72-73:026-154
72-73:026-155
72-73:026-159
72-73:026-160
367
-------
Drainage
(Cont.
72-
72-
72-
72-
72-
72-
72.
72.
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
73:020-161
73:020-166
73:020-167
73:020-168
73:020-171
73:020-173
73:020-193
73:020-203
73:020-211
-73:020-212
73:020-214
73:020-215
73:020-216
73:020-217
73:020-218
73:020-219
73:020-220
73:03F-015
73:03F-018
73:03F-034
73:03F-060
73:03F-066
73:04A-005
73:04A-033
73:04A-037
73:04A-084
73:048-012
73:048-013
73:058-032
73:058-084
73:058-091
73:05F-003
73:050-016
73:078-005
73:088-001
Drainage Area
72-73:020-030
72-73:020-160
72-73:020-161
Drainage Effects
72-73:020-030
72-73:020-042
72-73:020-101
72-73:020-114
72-73:03F-012
72-73:03F-034
72-73:050-016
Drainage Engineering
72-73:02F-075
72-73:020-030
72-73:020-042
72-73:020-043
72-73:020-056
72-73:020-072
Drainage Engineering
(Cont.)
72-73:020-139
72-73:020-160
72-73:020-161
72-73:020-171
72-73:020-173
72-73:020-216
72-73:020-217
72-73:020-218
72-73:020-219
72-73:050-008
Drainage Practices
72-73:02F-075
72-73:020-030
72-73:020-072
72-73:020-139
72-73:020-159
72-73:058-020
Drainage Programs
72-73:020-160
72-73:020-161
72-73:048-011
Drainage Systems
72-73:02F-075
72-73:020-030
72-73:020-072
72-73:020-128
72-73:020-139
72-73:020-160
72-73:020-161
72-73:020-171
72-73:04A-001
72-73:04A-005
72-73:04A-027
Drainage Water
72-73:020-004
72-73:058-020
72-73:058-029
72-73:050-005
Drains
72-73:020-072
72-73:020-139
72-73:04A-001
72-73:04A-033
Drawdown
72-73:020-002
72-73:02F-002
72-73:02F-003
72-73:02F-006
72-73:02F-007
72-73:02F-008
72-73:02F-011
Drawdown
(Cont.)
72-73:02F-012
72-73:02F-015
72-73:02F-018
72-73:02F-020
72-73:02F-029
72-73:02F-044
72-73:02F-046
72-73:02F-048
72-73:02F-052
72-73:02F-053
72-73:02F-057
72-73:02F-072
72-73:020-005
72-73:04A-001
72-73:04A-033
72-73:048-001
72-73:048-006
72-73:048-011
72-73:048-012
72-73:048-013
72-73:048-014
72-73:048-015
72-73:088-010
Dredging
72-73:02J-007
Drought Resistance
72-73:03F-025
Drought Tolerance
72-73:020-186
72-73:020-193
72-73:03F-030
Droughts
72-73:020-187
72-73:020-193
72-73:020-207
72-73:03F-018
72-73:03F-046
Dry Farming
72-73:020-013
72-73:020-186
72-73:020-227
72-73:03F-025
72-73:03F-027
72-73:03F-031
Drying
72-73:020-023
72-73:020-010
72-73:078-002
Dug Wells
72-73:02F-061
72-73:02F-083
368
-------
Dupuit-Forchheimer Theory
72-73:02F-007
72-73:02F-015
72-73:02F-050
72-73:02F-072
72-73:020-004
72-73:04A-001
Dye Releases
72-73:02F-078
72-73:020-063
72-73:07B-001
Dyes
72-73:05B-018
Dynamic Programming
72-73:03F-006
72-73:03F-017
72-73:03F-021
72-73:04A-003
E. Coli
72-73:050-001
Earth-Water Interfaces
72-73:020-035
Ecology
72-73:020-067
Economic Feasibility
72-73:03F-009
72-73:03F-010
72-73:03F-011
72-73:06A-005
Economics
72-73:038-001
72-73:03C-001
72-73:03F-046
72-73:04A-029
72-73:050-011
72-73:06A-001
72-73:060-001
72-73:060-002
Ecosystems
72-73:04D-001
72-73:05C-001
72-73:05C-002
Edge Effect
72-73:020-064
Efficiencies
72-73:020-013
72-73:020-129
72-73:020-153
72-73:020-178
Efficiencies
(Cont.)
72-73:021-005
72-73:03F-001
72-73:03F-019
72-73:03F-025
72-73:03F-031
72-73:03F-046
Effluents
72-73:050-001
72-73:050-013
72-73:050-005
Elastic Deformation
72-73 :02F-058
Elastic Hieory
72-73:02F-058
Electrical Conductance
72-73:020-002
72-73:020-059
72-73:020-108
72-73:020-117
72-73:03F-001
72-73:03F-019
Electrical Studies
72-73:020-059
Electrochemistry
72-73:050-014
Electrodes
72-73:02K-007
72-73:050002
Electrolytes
72-73:020-077
72-73:030-008
Emerging Vegetation State
72-73:03F-031
Encroachment
72-73:02F-028
72-73:02F-030
Endrin
72-73:050-010
Energy
72-73:020-035
Energy Budget
72-73:07B-002
Energy Conversion
72-73:021-017
Enteric Bacteria
72-73:05C-003
Entomology
72-73:053-060
Environment
72-73:02A-006
72-73:020-067
Environmental Control
72-73:040-001
Environmental Effects
72-73:02A-006
72-73:020-101
72-73:030-003
72-73:048-030
72-73:058-014
72-73:050-001
72-73:050-016
72-73:078-002
Environmental Engineering
72-73:020-157
72-73:058-068
72-73:056-092
72-73:05B-093
Environmental Sanitation
72-73:050-009
Ephemeral Streams
72-73:02E-003
Equations
72-73:02A-004
72-73:020-003
72-73:020-024
72-73:02F-002
72-73:02F-012
72-73:02F-026
72-73:02F-029
72-73:02F-035
72-73:02F-036
72-73:02F-037
72-73:02F-040
72-73:02F-052
72-73:02F-053
72-73:02F-058
72-73:02F-060
72-73:02F-072
72-73:020-009
72-73:020-011
72-73:020-014
72-73:020-025
72-73:020-090
72-73:020-093
72-73:020-095
369
-------
Equations
(Cont.)
72-73:020-131
72-73:02J-005
72-73:02J-006
72-73:04A-035
72-73:048-014
72-73:053-011
72-73:05B-026
72-73:050-011
72-73:06A-004
72-73:06D-001
72-73:06D-002
72-73:088-002
Equilibrium
72-73:02P-047
72-73:020-123
72-73:02K-003
Equipment
72-73:02F-017
Erosion
72-73:02E-007
72-73:02E-011
72-73:02E-013
72-73:02J-001
72-73:02J-002
72-73:02J-006
72-73:02J-009
72-73:02J-010
72-73:02J-011
72-73:02J-012
72-73:02J-013
72-73:02J-014
72-73:058-047
72-73:058-058
72-73:058-075
72-73:058-091
72-73:058-095
72-73:088-003
Erosion Control
72-73:020-056
72-73:02J-005
72-73:02J-008
72-73:02J-014
72-73:040-002
72-73:04D-003
72-73:058-003
72-73:058-030
Erosion Rates
72-73:02E-007
72-73:02J-014
Estimating
72-73:030-001
Estimating
(Cont.)
72-73:03F-006
72-73:03F-020
72-73:03F-021
72-73:03F-039
72-73:04A-003
72-73:058-068
72-73:050-011
72-73:068-001
72-73:06D-001
Estimating Equations
72-73:020-006
Estuaries
72-73:058-010
72-73:05C-010
Eutrophication
72-73:058-002
72-73:05C-001
72-73:050-005
Evaluation
72-73:03C-001
Evaporation
72-73:020-001
72-73:020-003
72-73:020-014
72-73:020-015
72-73:020-016
72-73:020-018
72-73:020-023
72-73:020-024
72-73:020-025
72-73:020-028
72-73:020-029
72-73:020-030
72-73:020-032
72-73:020-034
72-73:020-035
72-73:020-036
72-73:02F-055
72-73:02F-056
72-73:020-029
72-73:020-089
72-73:020-131
72-73:020-146
72-73:020-175
72-73:020-227
72-73:03F-001
72-73:03F-002
72-73:03F-025
72-73:03F-029
72-73:058-092
Evaporation Control
72-73:020-026
72-73:020-032
72-73:020-029
72-73:03F-061
Evaporimeters
72-73:020-014
72-73:020-015
72-73:020-023
Evapotranspiration
72-73:020-001
72-73:020-002
72-73:020-004
72-73:020-005
72-73:020-006
72-73:020-007
72-73:020-008
72-73:020-009
72-73:020-010
72-73:020-013
72-73:020-017
72-73:020-018
72-73:020-019
72-73:020-020
72-73:020-021
72-73:020-027
72-73:020-028
72-73:020-030
72-73:020-031
72-73:020-032
72-73:020-034
72-73:020-038
72-73:02F-038
72-73:02F-043
72-73:02F-056
72-73:020-026
72-73:020-031
72-73:020-047
72-73:020-110
72-73:020-111
72-73:020-153
72-73:020-154
72-73:020-164
72-73:020-172
72-73:020-194
72-73:020-203
72-73:020-224
72-73:021-011
72-73:021-012
72-73:021-013
72-73:021-019
72-73:03F-007
72-73:03F-010
72-73:03F-012
72-73:03F-019
72-73:03F-025
72-73:03F-031
370
-------
Evapotranspiration
(Cont.)
72-73:03F-039
72-73:03F-046
72-73:03F-063
72-73:03F-067
72-73:048-004
72-73:050-015
72-73:06A-005
72-73:078-002
72-73:10A-001
Evapotranspiration Control
72-73:020-005
Expansive Clays
72-73:02G-058
72-73:026-063
72-73:020-100
Expansive Soils
72-73:020-024
72-73:020-058
72-73:020-063
72-73:020-100
Facilities
72-73:06A-004
Failures
72-73:04A-005
72-73:086-011
Fallout
72-73:02K-001
Fallowing
72-73:020-027
72-73:020-136
72-73:020-157
72-73:058-075
Farm Management
72-73:02D-037
72-73:020-042
72-73:03F-002
72-73:03F-051
72-73:03F-052
72-73:03F-055
72-73:04A-038
72-73:04A-079
72-73:08C-001
Farm Ponds
72-73:03F-054
Farm Wastes
72-73:058-004
72-73:058-005
72-73:058-020
Farm Wastes
(Cont.)
72-73:058-022
72-73:058-023
72-73:058-057
72-73:058-067
72-73:058-095
72-73:058-096
Farms
72-73:03F-014
72-73:03F-039
Feasibility
72-73:04A-003
Feed Lots
72-73:058-018
72-73:058-067
72-73:05D-007
Fertility
72-73:020-121
72-73:020-130
72-73:020-143
72-73:020-176
72-73:020-177
72-73:020-180
72-73:020-182
72-73:020-183
72-73:020-185
72-73:020-196
72-73:020-205
72-73:020-209
72-73:020-228
72-73:021-003
72-73:021-006
72-73:03F-026
72-73:03F-060
72-73:04D-003
72-73:058-051
72-73:058-077
72-73:058-078
72-73:058-079
72-73:058-082
Fertilization
72-73:020-101
72-73:020-177
72-73:020-178
72-73:020-180
72-73:020-183
72-73:020-228
72-73:021-003
72-73:03F-015
72-73:04A-079
72-73:058-023
72-73:058-029
72-73:058-077
72-73:05D-002
Fertilizers
72-73:02D-013
72-73:02E-011
72-73:020-055
72-73:020-101
72-73:020-123
72-73:020-135
72-73:020-136
72-73:020-142
72-73:020-178
72-73:020-185
72-73:020-205
72-73:020-209
72-73:021-007
72-73:03F-027
72-73:04A-066
72-73:058-001
72-73:058-005
72-73:058-020
72-73:058-022
72-73:058-034
72-73:058-036
72-73:058-037
72-73:058-041
72-73:058-042
72-73:058-043
72-73:058-044
72-73:058-046
27-73:058-047
72-73:058-048
72-73:058-050
72-73:058-056
72-73:058-057
72-73:058-058
72-73:058-061
72-73:058-063
73-73:058-064
72-73:058-067
72-73:058-069
72-73:058-075
72-73:058-080
72-73:058-082
72-73:058-088
72-73:058-095
72-73:058-096
72-73:050-014
72-73:050-013
Fiber Crops
72-73:060-002
Field Capacity
72-73:020-026
72-73:03F-007
72-73:03F-008
Field Investigations
72-73:04A-005
371
-------
Filters
72-73:020-072
Filtration
72-73:020-072
72-73:050-003
72-73:05D-014
Finite Element Analysis
72-73:02F-010
72-73:02E-001
72-73:02F-025
72-73:02F-032
72-73:02F-033
72-73:02F-037
72-73:02F-054
72-73:02F-059
72-73:02F-069
72-73:020-011
72-73:020-036
72-73:020-150
72-73:04B-015
72-73:05B-012
72-73:08B-010
Fish
72-73:050010
Fishkill
72-73:050010
Fixed Costs
72-73:03F-004
Flame Photometry
72-73:05A-004
Flood Irrigation
72-73:05B-063
Flood Routing
72-73:070001
Flood Waves
72-73:02E-003
Flooding
72-73:020-109
Flow
(Cont.)
72-73:02E-004
72-73:02E-012
72-73:02F-059
72-73:020-046
72-73:020-150
72-73:020-167
72-73:050-004
Flow Characteristics
72-73:020-004
Flow Measurement
72-73:04A-034
72-73:04A-041
72-73:076-005
72-73:088-001
Flow Nets
72-73:02F-037
72-73:04A-004
72-73:086-002
Flow Rates
72-73:04A-041
Flowmeters
72-73:020-091
Fluctuations
72-73:03F-026
Fluid Friction
72-73:02F-039
72-73:088-007
Fluid Mechanics
72-73:02F-039
72-73:088-001
72-73:088-004
72-73:088-005
72-73:088-006
Flumes
72-73:04A-009
72-73:04A-041
72-73:088-001
Foods
(Cont.)
72-73:050010
72-73:06D-002
Forage Grasses
72-73:02D-013
72-73:03F-025
Forages
72-73:04A-015
72-73:058-041
72-73:058-042
Forecasting
72-73:030002
72-73:03F-008
72-73:06D-001
Forest Management
72-73:036-001
72-73:04A-030
72-73:04A-033
72-73:040-001
Forest Soils
72-73:020-154
72-73:04A-030
Forest Watersheds
72-73:020-154
Forestry
72-73:020-154
Forests
72-73:04A-030
Fourier Analysis
72-73:02F-041
72-73:03F-065
72-73:058-019
Fracture Permeability
72-73:020-063
Fractures (Geologic)
72-73:02F-022
Floods
72-73:02E-003
Florida
72-73:02F-008
72-73:02K-005
72-73:058-017
Flow
72-73:02D-018
Fluorescence
72-73:05A-001
Fluorescent Dye
72-73:020-058
Food Chains
72-73:05C-010
Foods
72-73:03F-018
372
Free Surfaces
72-73:02F-069
72-73:020-167
Freezing
72-73:020-087
72-73:05A-002
Frequency Analysis
72-73:02D-006
-------
Frequency Analysis
(Cent.)
72-73:02D-007
72-73:020-008
72-73:02D-009
72-73:02E-002
72-73:02P-041
72-73:053-019
Frequency Curves
72-73:02E-002
Fringe Water
72-73:03F-023
Frost
72-73:020-087
Frost Heaving
72-73:020-087
Frozen Soils
72-73:020-087
Fungi
72-73:050-001
Fungicides
72-73:050-010
Furrow Irrigation
72-73:02E-008
72-73:020-032
72-73:020-056
72-73:03F-011
72-73:03F-047
72-73:03F-053
72-73:03F-054
72-73:03F-057
72-73:03F-068
72-73:04A-006
72-73:04A-009
72-73:04A-039
72-73:04A-043
72-73:04A-055
72-73:04A-056
72-73:04A-057
72-73:04A-068
72-73:04A-069
72-73:04A-072
72-73:04A-083
Gages
72-73:02J-004
Gaging
72-73:02J-004
Gaging Stations
72-73:04A-041
Gamma Rays
72-73:020-084
72-73:020-104
72-73:020-138
Gases
72-73:053-092
Geochemistry
72-73:02F-013
72-73:02K-003
72-73:02K-006
Geophysics
72-73:020-059
Georgia
72-73:02F-021
72-73:02F-030
72-73:058-036
Germination
72-73:020-195
72-73:030-003
72-73:030-004
Glacial Drift
72-73:02F-049
Grain Sorghum
72-73:020-032
72-73:020-184
72-73:021-011
72-73:03F-031
72-73:03F-073
Grains (Crops)
72-73:020-047
72-73:03F-026
Grassed Water Ways
72-73:02J-005
Grasses
72-73:020-005
72-73:020-008
72-73:020-154
72-73:020-198
72-73:021-020
72-73:058-044
Grasslands
72-73:020-013
72-73:058-044
Gravels
72-73:03F-061
Great Plains
72-73:020-010
Great Plains
(Cont.)
72-73:020-013
72-73:02F-023
72-73:03F-025
Greenhouses
72-73:058-089
Groundwater
72-73:02A-001
72-73:02A-008
72-73:02A-010
72-73:020-002
72-73:020-029
72-73:02F-001
72-73:02F-013
72-73:02F-019
72-73:02F-038
72-73:02F-051
72-73:02F-055
72-73:02F-061
72-73:02F-066
72-73:02F-067
72-73:02F-071
72-73:02F-074
72-73:02F-077-
72-73:02F-079
72-73:02F-080
72-73:02F-081
72-73:02F-082
72-73:02F-083
72-73:02F-084
72-73:020-037
72-73:020-173
72-73:02K-001
72-73:02K-005
72-73:03E-001
72-73:03F-017
72-73:048-005
72-73:048-020
72-73:048-030
72-73:058-002
72-73:058-005
72-73:058-006
72-73:058-007
72-73:058-018
72-73:058-020
72-73:058-039
72-73:058-041
72-73:058-042
72-73:058-043
72-73:058-044
72-73:058-046
72-73:058-062
72-73:058-064
72-73:058-085
72-73:058-088
72-73:050-002
373
-------
Gr oundwat e r
(Cont.)
72-73:05D-007
72-73:050-010
72-73:06E-001
72-73:06E-003
72-73:06E-005
Groundwater Availability
72-73:02F-061
72-73:02F-073
72-73:02F-083
72-73:048-009
72-73:048-020
Groundwater Basins
72-73:02A-005
72-73:02K-003
Groundwater Mining
72-73:02F-073
Groundwater Movement
72-73:02A-001
72-73:02F-002
72-73:02F-003
72-73:02F-004
72-73:02F-005
72-73:02F-009
72-73:02F-010
72-73s02F-011
72-73:02F-012
72-73:02F-014
72-73:02F-015
72-73:02F-016
72-73:02F-018
72-73:02F-019
72-73:02F-020
72-73:02F-022
72-73:02F-025
72-73:02F-026
72-73:02F-027
72-73:02F-028
72-73:02F-029
72-73:02F-030
72-73:02F-031
72-73:02F-032
72-73s02F-033
72-73:02F-034
72-73:02F-035
72-73s02F-036
72-73:02F-037
72-73:02F-039
72-73s02F-040
72-73:02F-042
72-73:02F-044
72-73:02F-046
72-73:02F-047
72-73:02F-048
72-73:02F-049
Groundwater Movement
{Cont.)
72-73:02F-050
72-73:02F-054
72-73:02F-056
72-73:02F-057
72-73:02F-058
72-73:02F-060
72-73:02F-072
72-73:02F-078
72-73:026-003
72-73:020-004
72-73:020-005
72-73:020-012
72-73:02G-033
72-73:026-036
72-73:026-037
72-73:026-158
72-73:026-159
72-73:026-168
72-73:026-170
72-73:026-173
72-73:02K-005
72-73:03F-012
72-73:04A-001
72-73:04A-004
72-73:04A-033
72-73:04A-034
72-73:04B-002
72-73:048-006
72-73:048-014
72-73:048-015
72-73:048-016
72-73:058-001
72-73:058-006
72-73:058-007
72-73:058-011
72-73:058-012
72-73:058-017
72-73:058-018
72-73:058-021
72-73:058-022
72-73:058-025
72-73:058-026
72-73:050-002
72-73:088-002
72-73:088-010
Groundwater Potential
72-73:02A-008
72-73:02A-010
72-73:02F-081
72-73:02F-082
72-73:026-092
Groundwater Recharge
72-73:02F-066
72-73:02F-073
72-73:048-003
72-73:048-008
Groundwater Recharge
(Cont.)
72-73:048-030
Groundwater Resources
72-73:02A-008
72-73:02A-010
72-73:02F-059
72-73:02F-083
72-73:048-020
Growth
72-73:03F-028
Growth Chambers
72-73:03C-004
Growth Rates
72-73:026-191
72-73:03F-063
72-73:03F-065
6rowth Stages
72-73:020-008
72-73:03F-030
72-73 :03F-065
Gypsum
72-73:026-077
72-73:026-097
72-73:026-225
72-73:03F-034
72-73:04A-005
72-73:058-081
Harbors
72-73:056-003
Hardness (Water)
72-73:058-083
Hardpan
72-73:026-094
Hawaii
72-73:026-221
72-73:03F-007
72-73:04A-072
72-73:058-088
Hay
72-73:021-020
72-73:058-082
Hazards
72-73:050-013
Head Loss
72-73:050-011
72-73:088-004
374
-------
Head Loss
(Cont.)
72-73:08B-006
Heat
72-73:02D-019
Heat Flow
72-73:020-091
72-73:020-092
72-73:05B-011
Heat Resistance
72-73:030-003
Heating
72-73:05B-089
Heavy Metals
72-73:05A-004
72-73:05C-010
72-73:050-006
Heptachlor
72-73:05C-010
Herbicides
72-73:056-022
72-73:058-059
72-73:053-065
72-73:058-071
72-73:056-094
72-73:050-010
Heterogeneity
72-73:02F-009
Highway Icing
72-73:058-014
History
72-73:02F-001
72-73:04A-018
72-73:048-002
Hogs
72-73:058-095
Horticulture
72-73:04A-044
Hortons Law
72-73:020-151
Human Population
72-73:06D-002
Humic Acids
72-73:020-140
Humidity
72-73:020-001
72-73:020-003
72-73:020-014
72-73:020-015
72-73:020-016
72-73:028-001
Humus
72-73:020-140
Hybrid Computers
72-73:058-016
Hydration
72-73:020-016
Hydraulic Conductivity
72-73:02A-005
72-73:02F-002
72-73:02F-003
72-73:02F-009
72-73:02F-010
72-73:02F-016
72-73:02F-029
72-73:02F-039
72-73 :02F-049
72-73:02F-050
72-73:02F-058
72-73:020-003
72-73:020-006
72-73:020-007
72-73:020-011
72-73:020-013
72-73:020-015
72-73:020-017
72-73:020-021
72-73:020-022
72-73:020-024
72-73:020-025
72-73:020-058
72-73:020-060
72-73:020-062
72-73:020-063
72-73:020-064
72-73:020-075
72-73:020-076
72-73:020-078
72-73:020-080
72-73:020-082
72-73:020-083
72-73:020-088
72-73:020-096
72-73:020-097
72-73:020-131
72-7e:020-134
72-73:020-158
72-73:020-206
72-73:021-009
72-73:03F-008
Hydraulic Conductivity
(Cont.)
72-73:03F-012
72-73:03F-023
72-73:04A-033
72-73S04A-034
72-73:058-040
Hydraulic Conduits
72-73:088-007
Hydraulic Design
72-73:088-007
Hydraulic Equipment
72-73:08C-002
Hydraulic Gradient
72-73:020-004
72-73:020-206
72-73:058-018
Hydraulic Models
72-73:02F-005
72-73:02F-034
72-73:02F-040
72-73:020-004
72-73:020-005
72-73:020-015
72-73:020-022
72-73:02J-007
72-73:04A-028
72-73:04A-032
72-73:048-015
72-73:088-004
Hydraulic Radius
72-73:02F-039
Hydraulic Similitude
72-73:02F-005
72-73:020-082
Hydraulic Structures
72-73:03F-011
72-73:088-001
72-73:088-011
Hydraulic Valves
72-73:04A-063
Hydraulics
72-73:02F-027
72-73:020-046
72-73:020-150
72-73:020-152
72-73:020-158
72-73:02J-007
72-73:02J-011
72-73:03F-015
375
-------
Hydraulics
(Cont.)
72-73:03F-018
72-73t04A-028
72-73:04A-036
72-73t04A-037
72-73:04A-072
72-73:050-011
72-73:050-003
72-73:050-011
72-73:08B-004
72-73:08B-005
72-73:086-006
Hydroelectric Power
72-73:056-003
Hydrogen Ion Concentration
72-73:026-098
72-73tOSC-001
72-73:050-002
Hydroge ology
72-73:02A-004
72-73:02F-008
72-73:02F-014
72-73i02F-029
72-73:02F-038
72-73:02F-044
72-73:02F-048
72-73:02F-049
72-73:02F-050
72-73:02F-052
72-73:02F-060
72-73:02F-078
72-73:02J-002
72-73:02K-003
72-73:02K-005
72-73:02K-006
72-73:04A-001
72-73:04A-002
72-73:04A-003
72-73:04A-006
72-73:048-010
72-73:048-011
72-73:058-006
72-73:050-002
Hydrograph Analysis
72-73:02A-001
72-73:02F-021
72-73:02F-038
Hydrographs
72-73:07C-001
Hydrologic Aspects
72-73:050-002
Hydrologic Budget
72-73:02F-030
72-73:02F-041
Hydrologic Cycle
72-73:020-021
72-73:020-035
72-73:040-001
72-73:06E-005
Hydrologic Oata
72-73:020-027
72-73:020-051
72-73:058-013
Hydrologic Equation
72-73:02A-004
Hydrologic Systems
72-73:050-002
Hydrology
72-73:02F-004
72-73:02E-003
72-73:02E-004
72-73:020-037
72-73:03F-017
72-73:048-008
72-73:040-004
Hydroponics
72-73:020-179
72-73:10A-002
Hysteresis
72-73:020-009
72-73:020-010
72-73:020-015
Ice
72-73:020-087
Ice Breakup
72-73:02C-001
Idaho
72-73:020-006
72-73:058-007
72-73:050-003
72-73:050-002
Illinois
72-73:058-003
Impact (Rainfall)
72-73:020-035
72-73:040-002
Impervious Membranes
72-73:03E-001
Impervious Membranes
(Cont.)
72-73:04A-040
Impervious Soils
72-73:03F-012
Incubation
72-73:020-119
72-73:05C-002
Indexing
72-73:020-019
Industrial Production
72-73:05C-010
Industrial Wastes
72-73.-05A-004
72-73:058-022
Infiltration
72-73:02A-001
72-73:02A-004
72-73:02F-010
72-73:02E-003
72-73:02F-021
72-73:02F-023
72-73:02F-043
72-73:02F-053
72-73:02F-056
72-73:020-006
72-73:020-007
72-73:020-009
72-73:020-011
72-73:020-012
72-73:020-013
72-73:020-014
72-73:020-015
72-73:020-017
72-73:020-024
72-73:020-025
72-73:020-034
72-73:020-035
72-73:020-046
72-73:020-060
72-73:020-061
72-73:020-062
72-73:020-064
72-73:020-075
72-73:020-078
72-73:020-082
72-73:020-090
72-73:020-093
72-73:020-094
72-73:020-095
72-73:020-097
72-73:020-100
72-73:020-114
72-73:020-129
376
-------
Infiltration
(Cont.)
72-73:026-131
72-73:020-134
72-73:026-146
72-73:026-151
72-73:020-152
72-73:026-170
72-73:026-223
72-73:02K-004
72-73:03F-001
72-73:03F-008
72-73:03F-019
72-73:04A-006
72-73:04A-021
72-73:04A-032
72-73.-04A-034
72-73:04A-069
72-73:04A-075
72-73:04A-072
72-73:04B-008
72-73:04B-016
72-73:04D-002
72-73:053-006
72-73:058-017
72-73:053-020
72-73:053-028
72-73:053-092
72-73:083-002
Infiltration Rates
72-73:026-032
72-73:026-046
72-73:026-151
72-73:026-170
72-73:026-184
72-73:026-223
72-73:03F-009
72-73:04A-007
72-73:04A-008
72-73:04A-021
72-73:04A-034
72-73:04A-069
72-7e:04A-075
Infiltrometers
72-73:026-009
72-73:026-151
72-73:04A-075
Inflow
72-73:030002
72-73:03F-008
72-73:04A-069
Infrared Radiation
72-73:026-157
72-73:10A-003
Injection Wells
72-73:02F-027
72-73:02F-050
72-73:02F-084
72-73:043-002
Inorganic Compounds
72-73:02K-010
72-73:053-070
72-73:053-081
inorganic Pesticides
72-73:053-071
Input-Output Analysis
72-73:02F-041
72-73:033-001
Insecticides
72-73:050-010
Installation
72-73:026-171
Institutional Constraints
72-73:06E-004
Instrumentation
72-73:026-008
72-73:026-079
72-73:026-081
72-73:026-084
72-73:026-091
72-73:026-104
72-73:026-117
72-73:026-164
72-73:02J-004
72-73:10A-001
72-73:10A-003
Inter-Basin Transfers
72-73:053-015
Interfaces
72-73:02F-069
International Bound, and Water
Cornm.
72-73:02E-006
International Waters
72-73:02E-006
72-73:06E-003
Interstate
72-73:06E-003
Interstate Rivers
72-73:02E-006
Interstices
72-73:026-024
72-73:026-064
Investment
72-73:063-001
Ion Exchange
72-73:02F-047
72-73:026-001
72-73:026-016
72-73:026-021
72-73:026-023
72-73:026-058
72-73:026-098
72-73:026-099
72-73:026-123
72-73:026-140
72-73:026-147
72-73:026-225
72-73:02J-003
72-73:02K-011
72-73:05A-001
72-73:05A-004
72-73:058-011
72-73:053-016
72-73:053-021
72-73:053-025
72-73:050-014
72-73:05F-004
72-73:056-015
Ion Transport
72-73:020-025
72-73:02F-045
72-73:02F-047
72-73:026-018
72-73:026-020
72-73:026-023
72-73:026-061
72-73:026-086
72-73:026-087
72-73:026-089
72-73:026-099
72-73:026-205
72-73:026-220
72-73:04A-030
72-73:043-030
72-73:053-011
72-73:053-021
72-73:053-025
72-73:053-083
Ions
72-73:026-002
72-73:026-115
72-73:026-123
72-73:026-225
72-73:02K-008
72-73:02K-011
377
-------
Ions
(Cont.)
72-73:05A-004
72-73-.05A-005
Iowa
Iron
72-73:058-030
72-73:02G-103
72-73:020-105
Irrigated Land
72-73:03P-003
72-73s05B-032
72-73:056-013
Irrigation
72-73:020-009
72-73:020-020
72-73:02E-003
72-73:02E-008
72-73i02E-014
72-73:02F-021
72-73:02F-069
72-73:02F-079
72-73:026-026
72-73:026-032
72-73:026-045
72-73:026-046
72-73:026-047
72-73:026-071
72-73:026-116
72-73:026-129
72-73:026-156
72-73:026-163
72-73:026-173
72-73:026-191
72-73:026-196
72-73:026-197
72-73:026-201
72-73:026-204
72-73:026-207
72-73:026-208
72-73:026-210
72-73:026-213
72-73:026-221
72-73:026-223
72-73:026-224
72-73:021-020
72-73:030-001
72-73:03C-008
72-73:03P-003
72-73:03F-005
72-73:03F-008
72-73:03F-012
72-73:03F-014
72-73s03F-015
72-73:03F-016
72-73:03F-017
Irrigation
(Cont.)
72-73:03F-018
72-73:03F-021
72-73:03F-025
72-73:03F-042
72-73:03F-046
72-73:03F-047
72-73:03F-051
72-73:03F-052
72-73:03F-059
72-73:03F-060
72-73:03F-062
72-73:03F-066
72-73:03F-067
72-73:04A-005
72-73:04A-006
72-73:04A-009
72-73:04A-021
72-73:04A-025
72-73:04A-027
72-73:04A-037
72-73:04A-043
72-73:04A-045
72-73:04A-046
72-73:04A-047
72-73:04A-049
72-73:04A-050
72-73:04A-054
72-73:04A-060
72-73:04A-064
72-73:04A-067
72-73:04A-068
72-73:04A-071
72-73:04A-072
72-73:04A-073
72-73:04A-077
72-73:04A-079
72-73:04A-080
72-73:04A-084
72-73:04A-085
72-73:058-018
72-73:058-038
72-73:058-064
72-73:058-083
72-73:050-002
72-75:05E-001
72-73:056-016
72-73:06A-005
72-73:060-001
72-73:088-001
Irrigation Design
72-73:020-007
72-73:020-038
72-73:026-032
72-73:026-046
72-73:026-116
72-73:026-155
72-73s03F-002
Irrigation Design
(Cont.)
72-73:03F-003
72-73:03F-042
72-73:03F-047
72-73:03F-064
72-73:04A-007
72-73 .-04A-009
72-73:04A-012
72-73:04A-020
72-73:04A-021
72-73:04A-023
72-73:04A-029
72-73:04A-042
72-73:04A-050
72-73:04A-058
72-73:04A-059
72-73:04A-065
72-73:04A-068
72-73:04A-070
72-73:04A-074
72-73:04A-076
72-73:04A-077
72-73:04A-080
72-73:04A-082
72-73:04A-083
72-73:048-004
72-73:088-005
Irrigation Districts
72-73S03F-016
Irrigation Effects
72-73:026-159
72-73:026-208
72-73:026-213
72-73:03C-002
72-73:03C-004
72-73:03F-066
72-73:03F-067
72-73:04A-084
72-73:043-030
72-73:058-032
72-73:05C-003
Irrigation Efficiency
72-73:020-010
72-73:02E-008
72-73:026-032
72-73:026-047
72-73:03C-001
72-73:03F-002
72-73:03F-003
72-73:03F-007
72-73:03F-009
72-73:03F-013
72-73:03F-020
72-73:03F-021
72-73:03F-039
72-73:03F-042
378
-------
Irrigation Efficiency
(Cont.)
72-73:03F-051
72-73:03F-052
72-73:03F-057
72-73:03F-063
72-73:03F-065
72-73:03F-066
72-73:03F-067
72-73:04A-012
72-73:04A-021
72-73:04A-025
72-73:04A-042
72-73:04A-048
72-73:04A-068
72-73:04A-073
72-73:050-001
Irrigation Engineering
72-73:02D-036
72-73:02E-008
72-73:02G-046
72-73ğ02G-047
72-73:02G-221
72-73:020-224
72-73:03F-006
72-73:03F-014
72-73:03F-042
72-73:03F-057
72-73:04A-021
72-73:04A-023
72-73:04A-025
72-73:04A-029
72-73:04A-042
72-73:088-005
Irrigation Operation and
Maintenance
72-73:03F-006
72-73:03F-013
72-73:03F-051
72-73:03F-052
72-73:03F-057
72-73:04A-005
72-73:048-005
Irrigation Practices
72-73:02D-006
72-73:02D-020
72-73s02D-033
72-73:02D-036
72-73:02E-008
72-73:026-029
72--33:02G-030
72-73:020-032
72-73:020-041
72-73:020-046
72-73:020-047
72-73:020-116
72-73:020-153
Irrigation Practices (Cont.)
72-73:020-155
72-73:020-162
72-73:020-165
72-73:020-166
72-73:020-174
72-73:020-175
72-73:020-191
72-73:020-196
72-73:020-201
72-73:020-204
72-73:020-207
72-73:020-208
72-73:020-210
72-73:020-213
72-73:020-215
72-73:020-221
72-73:020-222
72-73:020-224
72-73:030-001
72-73:030-002
72-73:030-007
72-73:03Fr-010
72-73:03F-016
72-73.-03F-020
72-73:03F-039
72-73:03F-042
72-73:03F-047
72-73:03F-051
72-73:03F-052
72-73:03F-053
72-73:03F-054
72-73:03F-056
72-73:03F-062
72-73:03F-063
72-73.-03F-071
72-73:03F-072
72-73:03F-073
72-73:04A-007
72-73:04A-008
72-73:04A-009
72-73:04A-012
72-73:04A-015
72-73:04A-017
72-73:04A-018
72-73:04A-020
72-73:04A-021
72-73:04A-025
72-73:04A-029
72-73:04A-038
72-73:04A-039
72-73:04A-042
72-73:04A-043
72-73:04A-044
72-73:04A-045
72-73:04A-046
72-73:04A-047
72-73:04A-048
72-73:04A-049
72-73:04A-050
72-73:04A-051
Irrigation Practices
(Cont.}
72-73:04A-052
72-73:04A-053
72-73:04A-054
72-73:04A-055
72-73:04A-056
72-73:04A-057
72-73:04A-058
72-73:04A-059
72-73:04A-060
72-73:04A-061
72-73:04A-062
72-73:04A-063
72-73:04A-064
72-73:04A-065
72-73:04A-066
72-73:04A-067
72-73:04A-068
72-73:04A-069
72-73:04A-070
72-73:04A-071
72-73:04A-072
72-73:04A-074
72-73:04A-076
72-73:04A-077
72-73:04A-078
72-73:04A-080
72-73:04A-081
72-73:04A-082
72-73:04A-083
72-73:04A-085
72-73:048-005
72-73:040-001
72-73:058-005
72-73:058-032
72-73:058-063
72-73:05C-008
72-73:050-016
72-73:088-005
72-73:088-006
Irrigation Programs
72-73:020-208
72-73:03F-004
72-73:03F-010
72-73:03F-014
72-73:03F-017
72-73:03F-067
72-73:03F-071
72-73:03F-072
72-73 .-03F-073
72-73:04A-060
72-73:04A-067
72-73:04A-078
Irrigation Systems
72-73:02E-008
72-73:020-116
379
-------
Irrigation Systems
(Cent.)
72-73:020-155
72-73:02G-163
72-73:02G-213
72-73:020-215
72-73:03F-002
72-73:03F-004
72-73:03F-009
72-73:03F-011
72-73:03F-012
72-73:03F-039
72-73:03F-042
72-73:03F-047
72-73:03F-051
72-73:03F-052
72-73:03F-057
72-73:03F-063
72-73:03F-064
72-73:03F-067
72-73:03F-071
72-73:03F-072
72-73:03F-073
72-73:04A-007
72-73:04A-012
72-73:04A-020
72-73:04A-023
72-73:04A-025
72-73J04A-027
72-73:04A-028
72-73:04A-029
72-73:04A-039
72-73-.04A-042
72-73:04A-043
72-73:04A-045
72-73:04A-046
72-73:04A-047
72-73:04A-048
72-73:04A-049
72-73:04A-051
72-73:04A-052
72-73:04A-054
72-73:04A-055
72-73:04A-056
72-73:04A-057
72-73:04A-058
72-73:04A-059
72-73:04A-061
72-73:04A-062
72-73s04A-064
72-73:04A-070
72-73:04A-073
72-73:04A-074
72-73:04A-076
72-73:04A-077
72-73:04A-078
72-73:04A-081
72-73:04A-082
72-73:04A-083
Irrigation Systems
(Cont.)
72-73:056-013
72-73:050-015
72-73:086-005
Irrigation Water
72-73:02F-001
72-73:020-078
72-73:030-001
72-73:030-002
72-73:03F-006
72-73:03F-018
72-73:03F-039
72-73:03F-063
72-73:03F-071
72-73:04A-006
72-73:04A-012
72-73:04A-084
72-73:04B-005
72-73:04B-007
72-73:040-001
72-73:058-007
72-73:053-016
72-73:05B-027
72-73:056-032
72-73:050-003
72-73:05D-013
72-73:050-013
72-73:06A-001
72-73:06D-002
Irrigation Wells
72-73:048-007
Isotope Fractionation
72-73:02K-005
72-73:058-061
Isotope Studies
72-73:020-135
72-73:058-061
Joints (Geologic)
72-73:02F-022
Kaolinite
72-73:020-138
Karst
72-73:02F-013
72-73:02F-078
Karst Hydrology
72-73:02F-013
72-73:02F-041
72-73:02F-078
72-73:02K-006
Kinetics
72-73:02K-003
Labor
72-73:03F-030
Laboratory
72-73i
72-73s
72-73;
72-73;
72-73;
72-73;
72-73:
72-73i
72-73;
Tests
02F-017
02G-009
020-063
020-076
02G-083
020-096
:04A-032
058-002
088-001
Lake Morphology
72-73:050-002
Lake Sediments
72-73:058-008
Lakes
72-73:058-017
72-73:058-096
72-73:050-002
72-73:050-010
Laminar Flow
72-73:02F-005
72-73:02F-022
Land Development
72-73:04A-017
72-73:06D-003
Land Forming
72-73:04A-017
Land Management
72-73:02J-012
72-73:038-001
72-73:03F-055
72-73:04A-038
72-73:058-023
72-73:060-003
Land Reclamation
72-73:020-019
72-73:03F-034
72-73:03F-066
72-73:04A-033
Land Subsidence
72-73:02F-001
72-73:02F-036
380
-------
Land Tenure
72-73s03F-039
Land Use
72-73:02J-001
72-73:02J-006
72-73:02K-002
72-73:03P-039
72-73:04A-017
72-73:06D-002
72-73:060-003
Landfills
72-73:05B-092
72-73:053-093
Laplaces Equation
72-73:04A-001
Leachate
72-73:05A-004
Leaching
72-
72-
72-
72.
72
72
72
72-
72.
72.
72
72.
72
72.
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
72
73:020-025
73:02F-013
73:02E-011
73:02F-047
73:02G-012
73:020-019
73:020-036
73:020-055
73:020-058
73:020-086
73:020-087
73:020-094
73:020-095
73:020-099
73:020-101
73:020-103
73:020-105
73:020-106
73:020-107
73:020-109
73:020-114
73:020-119
73:020-123
73:020-133
73:020-135
73:020-178
73:020-181
73:020-183
73:020-184
73:020-200
73:020-205
73:02G-206
73:020-209
-73:020-226
-73:02J-003
-73:02K-002
-73:02K-003
Leaching
(Cont.)
72-73:02K-004
72-73:02K-009
72-73:03F-001
72-73:03F-019
72-73:03F-034
72-73:03F-060
72-73:03F-066
72-73:04A-030
72-73:043-011
72-73:04C-001
72-73:05A-004
72-73:053-001
72-73:053-016
72-73:053-017
72-73:053-020
72-73:053-021
72-73:053-024
72-73:053-025
72-73:053-027
72-73:053-029
72-73:053-033
72-73:053-041
72-73:053-042
72-73:053-043
72-73:053-044
72-73:053-045(Page 291)
72-73:053-046
72-73:053-047
72-73:053-048
72-73:053-049
72-73:053-050
72-73:053-053
72-73:053-054
72-73:053-058
72-73:053-065
72-73:053-069
72-73:053-072
72-73:053-075
72-73:053-080
72-73:053-081
72-73:053-083
72-73:053-085
72-73:053-086
72-73:053-087
72-73:053-091
72-73:053-092
72-73:053-093
72-73:053-095
72-73:050-008
72-73:050-008
72-73:050-010
72-73:050-012
72-73:050-016
Leakage
72-73:02F-025
72-73:03E-001
72-73:04A-032
Least Squares Method
72-73:053-068
Leaves
72-73:021-005
72-73:021-008
72-73:021-013
72-73:021-016
72-73:030005
72-73:030-009
72-73:03F-025
72-73:03F-027
72-73:03F-030
72-73:03F-031
72-73:073-002
Legal Aspects
72-73:06E-002
Legislation
72-73:06E-005
Legumes
72-73 :03F-025
Lettuce
72-73:03F-007
Limestones
72-73:02F-013
72-73:02F-078
Limiting Factors
72-73:020-013
72-73:030-003
72-73:03F-023
72-73:03F-031
72-73:053-096
Limnology
72-73:053-008
Linear Programming
72-73:02F-059
72-73:03F-005
72-73:03F-017
72-73:04A-003
72-73:050-003
72-73:050-004
72-73:06A-002
72-73:06A-004
72-73:060-001
Linings
72-73:020-033
72-73:03E-001
72-73:03F-025
Livestock
72-73:053-095
381
-------
Loam
72-73:020-096
72-73:03F-012
72-73:05A-004
Loess
72-73:05B-030
Long-Term Planning
72-73:03F-004
Lysimeters
72-73:02D-001
72-73:020-006
72-73:02D-007
72-73:02D-008
72-73:020-009
72-73:020-010
72-73:020-023
72-73:020-031
72-73:020-038
72-73:02G-008
72-73:020-031
72-73:02G-154
72-73:02G-163
72-73:026-164
72-73:020-193
72-73:021-012
72-73:021-013
72-73:03F-063
72-73:04A-030
72-73:04C-001
72-73:050-008
72-73:10A-001
Magnesium
72-73:020-145
72-73:02J-003
72-73:03F-025
72-73:058-016
72-73s05B-045(Page 291)
Maintenance
72-73:04A-005
Malenclaves
72-73s05B-006
72-73:05B-011
Management
72-73:02F-059
72-73:020-067
72-73:021-010
72-73:03F-013
72-73:03F-014
72-73:03F-021
72-73:03F-067
72-73:04A-038
72-73s050-005
72-73i05G-011
Management
(Cont.)
72-73:050-015
72-73:050-016
72-73:06A-004
Manganese
72-73:020-098
72-73:020-103
72-73:020-105
Mannings Equation
72-73:083-004
Mappi ng
72-73:020-027
Marketing
72-73:060-002
Markov Processes
72-73:02F-038
Marl
72-73:02H-001
Maryland
72-73:050-006
Mass Transfer
72-73:020-003
72-73:020-016
72-73:020-025
72-73:02F-030
72-73:02F-031
72-73:O2F-045
72-73:02F-047
72-73:020-036
72-73:020-059
72-73:020-061
72-73:020-087
72-73:020-089
72-73:02K-003
72-73:02K-004
72-73:058-010
72-73:058-011
72-73:058-021
Mathematical Models
72-73:02A-001
72-73:02A-002
72-73:02A-003
72-73:02A-005
72-73:02A-007
72-73:02A-008
72-73:020-001
72-73:020-004
72-73:020-020
72-73:020-034
72-73:02F-002
Mathematical Models
(Cont.)
72-73:02F-009
72-73:02F-010
73-73:02F-014
72-73:02E-003
72-73:02E-013
72-73:02F-015
72-73:02F-016
72-73:02F-018
72-73:02F-019
72-73:02F-020
72-73:02F-021
72-73:02F-022
72-73:02F-026
72-73:02F-030
72-73:02F-034
72-73:02F-037
72-73:02F-040
72-73:02F-050
72-73:02F-059
72-73:02F-066
72-73:02F-081
72-73-.02F-082
72-73:020-006
72-73:020-014
72-73:020-023
72-73:020-043
72-73:020-071
72-73:020-080
72-73:020-126
72-73:020-150
72-73:020-152
72-73:020-155
72-73:020-167
72-73:020-194
72-73:020-213
72-73:020-222
72-73:021-018
72-73:02J-005
72-73:02K-003
72-73:03F-005
72-73:03F-007
72-73:03F-014
72-73:03F-017
72-73:03F-018
72-73:03F-021
72-73:03F-065
72-73:04A-002
72-73:04A-003
72-73:04A-008
72-73:04A-012
72-73:04B-009
72-73:048-010
72-73:040-001
72-73:040-004
72-73:058-009
72-73:058-010
72-73:058-012
72-73:058-015
382
-------
Mathematical Models
(Cont.)
72-73:053-016
72-73:05B-017
72-73:058-026
72-73:050-001
72-73:050-003
72-73:05G-002
72-73:050-004
72-73:05G-005
72-73:05G-011
72-73:05G-012
72-73:06A-001
72-73:06A-003
72-73:06A-004
72-73:063-001
72-73:060-001
72-73:060-002
72-73:070-001
72-73:083-010
Mathematical Studies
72-73:02A-004
72-73:02F-002
72-73:02F-003
72-73:02F-004
72-73:02F-007
72-73:02E-001
72-73:02F-029
72-73:02F-032
72-73:02F-035
72-73:02F-036
72-73:02F-047
72-73:02F-050
72-73:02F-054
72-73:02F-056
72-73:02F-057
72-73:02F-058
72-73:02F-060
72-73:02F-072
72-73:02G-003
72-73:02G-025
72-73:026-090
72-73:020-093
72-73:03F-008
72-73:04A-004
72-73:04B-006
72-73:046-014
72-73:03B-012
72-73:05B-021
72-73:05B-026
Mature Growth Stage
72-73:03F-025
Measurement
72-73:02F-068
72-73:020-120
72-73:020-148
72-73:020-194
Measurement
(Cont.)
72-73:021-016
72-73:03F-002
72-73:10A-002
Membranes
72-73:04A-040
Mercury
72-73:020-124
72-73:050-010
72-73:050-006
Metabolism
72-73:030-008
72-73:050-001
Metals
72-73:050-010
Meteorological Data
72-73:020-003
72-73:020-027
Meteorology
72-73:020-016
Methane
72-73:02H-001
72-73:053-092
72-73:050-001
Methane Bacteria
72-73:02H-001
Methodology
72-73:05A-004
72-73:05A-005
72-73:050-014
Mexico
72-73:02E-006
Microbial Degradation
72-73:050-014
Microbiology
72-73:053-060
Microenvironment
72-73:073-002
Micrometeorology
72-73:020-006
Mineral Water
72-73 :02F-077
Mineralogy
72-73:050-002
Missouri River
72-73:06A-004
Mist
72-73:023-001
Mist Irrigation
72-73:020-163
72-73:03F-063
Mixing
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
73:020-001
73:02F-004
73:02F-017
73:02F-026
73:02F-027
73:02F-031
73:02F-034
73:02F-042
73:020-036
73:020-061
73:020-064
73:020-086
73:02K-004
73:053-010
73:053-012
73:053-025
73:053-026
Model Studies
72-73:02A-002
72-73:02A-006
72-73:02A-007
72-73:020-001
72-73:02F-014
72-73:02F-042
72-73:02F-050
72-73:020-005
72-73:020-015
72-73:020-019
72-73:020-022
72-73:020-043
72-73:020-152
72-73:02J-009
72-73:03F-004
72-73 :03F-006
72-73:04A-008
72-73:04A-028
72-73:04A-032
72-73:053-015
72-73:053-068
72-73:050-004
72-73:050-012
72-73:050-016
72-73:050-015
72-73:06A-002
72-73:070-001
383
-------
Moisture
72-73;02D-017
72-73:020-021
72-73:02B-001
72-73:021-015
72-73:03F-032
Moisture Availability
72-73:020-033
72-73:020-156
72-73:020-169
72-73:046-008
Moisture Content
72-73:020-026
72-73:020-031
72-73:020-059
72-73:020-076
72-73:020-088
72-73:020-100
72-73:020-156
72-73:020-164
72-73:03P-063
72-73:03F-064
72-73:10A-001
Moisture Deficit
72-73:03F-010
Moisture Meters
72-73:020-031
72-73:020-079
72-73:020-081
72-73:020-156
72-73:020-164
72-73:04A-075
72-73:10A-001
Moisture Stress
72-73:020-013
72-73:020-037
72-73:021-005
72-73:03F-025
72-73:03F-030
72-73:03F-031
Moisture Tension
72-73:02F-076
72-73:020-037
72-73:020-045
72-73:020-088
72-73:020-156
72-73:03F-010
Monitoring
(Cont.)
72-73:050-011
Monomolecular Films
72-73:020-032
Montana
72-73:06A-004
Monte Carlo Method
72-73:02F-057
Montmorillonite
72-73:020-125
72-73:020-138
Movement
72-73:03F-023
Mulch
72-73:020-146
Mulching
72-73:020-026
72-73:020-037
72-73:020-136
72-73:020-137
72-73:020-227
72-73:02J-008
72-73:02J-013
72-73:03F-061
Multiple-Purpose Reservoirs
72-73:04A-003
Municipal Wastes
72-73:05B-096
Nebraska
72-73:020-010
72-73:02F-023
72-73:058-005
Nematoeides
72-73:053-060
Nematodes
72-73:05B-060
Net Profit
72-73:03F-006
72-73:04B-009
Neutralization
72-73:03A-001
Nevada
72-73:02J-002
New Mexico
72-73:04B-020
72-73:060-001
New York
72-73:058-014
Nitrates
72-73:020-013
72-73:020-103
72-73:020-105
72-73:020-106
72-73:020-121
72-73:020-125
72-73:020-181
72-73:021-006
72-73:02K-008
72-73:02K-010
72-73:03F-015
72-73:03F-027
72-73:056-001
72-73:058-002
72-73:056-005
72-73:056-006
72-73:056-018
72-73:058-020
72-73:056-029
72-73:056-033
72-73:058-036
72-73:058-037
72-73:056-039
72-73:058-041
72-73:058-042
72-73:058-046
72-73:058-048
72-73:058-050
72-73:058-053
72-73:058-054
72-73:058-063
72-73:056-080
72-73:058-084
72-73:058-085
72-73:056-086
72-73:058-088
72-73:050-010
72-73:05F-004
72-73:050-013
Moisture Uptake
72-73:03F-023
Monitoring
72-73:04A-030
72-73:05C-010
Networks
72-73:020-027
72-73:03F-014
72-73:050-001
Nitrification
72-73:020-200
72-73:02H-001
72-73:056-002
72-73:058-040
72-73:058-046
384
-------
Nitrification
(Cont.)
72-73:050-002
72-73:05D-010
72-73:050-014
Nitrogen
72-73:020-013
72-73:02E-011
72-73:020-101
72-73:020-106
72-73:020-119
72-73:020-121
72-73:020-125
72-73:020-129
72-73:020-130
72-73:020-133
72-73:020-135
72-73:020-136
72-73:020-142
72-73:020-178
72-73:020-180
72-73:020-182
72-73:020-185
72-73:020-200
72-73:020-209
72-73:020-226
72-73:021-003
72-73:021-006
72-73:021-007
72-73:02K-010
72-73:03F-015
72-73:03F-026
72-73:053-018
72-73:053-029
72-73:053-033
72-73:053-037
72-73:053-039
72-73:053-040
72-73:053-041
72-73:053-042
72-73:053-043
72-73:053-044
72-73:053-045(Page 291}
72-73:053-046
72-73:053-047
72-73:053-048
72-73:053-051
72-73:053-052
72-73:053-053
72-73:053-056
72-73:053-058
72-73:053-061
72-73:053-064
72-73:053-072
72-73:053-075
72-73:053-077
72-73:053-078
72-73:053-079
Nitrogen
(Cont.)
72-73:053-080
72-73:053-082
72-73:053-085
72-73:053-086
72-73:053-088
72-73:053-091
72-73:05C-001
72-73:050002
72-73:050-008
72-73:050-012
72-73:050-014
Nitrogen Compounds
72-73:020-013
72-73:020-180
72-73:02K-010
72-73:03F-027
72-73:053-033
72-73:053-054
72-73:050-005
72-73:050-014
Nitrogen Cycle
72-73:020-200
72-73:02H-001
72-73:02K-010
72-73:053-048
72-73:053-050
72-73:053-054
72-73:05C-002
Nitrogen Fixation
72-73:020-119
72-73:020-200
72-73:02H-001
72-73:02K-010
72-73:053-054
72-73:05C-002
Nitrogen Fixing Bacteria
72-73:050-014
Non-Newtonian Flow
72-73:020-004
Non-Uniform Flow
72-73:02E-001
72-73:02F-026
North Carolina
72-73:03F-012
72-73:053-004
North Dakota
72-73:043-011
Nuclear Meters
72-73:020-079
Nuclear Meters
(Cont.)
72-73:020-081
72-73:020-084
72-73:02J-004
Nuclear Moisture Meters
72-73:020-079
72-73:020-081
72-73:020-084
72-73:020-104
Numerical Analysis
72-73 :02A-001
72-73:02E-001
72-73:02F-002
72-73:02F-003
72-73:02F-004
72-73:02F-009
72-73:02F-010
72-73:02F-011
72-73:02F-012
72-73 :02F-014
72-73:02F-015
72-73:02F-018
72-73:02F-019
72-73:02F-020
72-73:02F-021
72-73:02F-022
72-73:02F-025
72-73:02F-026
72-73:02F-029
72-73:02F-032
72-73:02F-033
72-73:02F-034
72-73:02F-035
72-73:02F-037
72-73:02F-040
72-73:02F-050
72-73:02F-054
72-73:02F-069
72-73:020-001
72-73:020-009
72-73:020-011
72-73:020-013
72-73:020-014
72-73:020-017
72-73:020-022
72-73:020-023
72-73:020-034
72-73:020-035
72-73:020-036
72-73:020-060
72-73:020-062
72-73:020-078
72-73:020-080
72-73:020-082
72-73:020-128
72-73:020-128
72-73:04A-006
385
-------
Numerical Analysis
(Cont.)
72-73:04A-006
72-73:04B-015
72-73:056-010
72-73:058-012
72-73:056-021
72-73:05B-022
72-73:058-025
Nutrient Removal
72-73:02E-011
72-73:026-055
72-73:020-101
72-73:026-102
72-73:026-106
72-73:020-109
72-73:020-118
72-73:020-119
72-73:020-123
72-73:020-126
72-73:020-133
72-73ğ02G-135
72-73:026-142
72-73:020-179
72-73:020-180
72-73:026-181
72-73:026-182
72-73:026-183
72-73:020-205
72-73:026-209
72-73:026-226
72-73:02J-013
72-73:058-002
72-73:058-034
72-73:053-041
72-73:058-042
72-73:058-043
72-73:058-044
72-73:058-045(Page 291)
72-73:058-046
72-73:058-047
72-73:058-048
72-73:058-049
72-73:058-050
72-73:058-052
72-73:058-053
72-73:058-054
72-73:058-056
72-73:058-057
72-73:058-058
72-73:058-063
72-73:058-064
72-73:058-069
72-73s05B-072
72-73:058-075
72-73:058-077
72-73t05B-078
72-73:05B-079
72-73:058-080
Nutrient Removal
(Cont.)
72-73:056-085
72-73:058-086
72-73:058-088
72-73:058-091
72-73:050-005
72-73:05D-012
72-73:05D-014
Nutrient Requirements
72-73:020-122
72-73:026-142
Nutrients
72-73:026-098
72-73:026-102
72-73:026-121
72-73:026-130
72-73:026-143
72-73:026-145
72-73:026-179
72-73:020-228
72-73:03P-018
72-73:058-005
72-73:058-036
72-73:058-051
72-73:058-069
72-73:058-087
72-73:058-095
72-73:058-096
72-73:050-001
72-73:050-002
72-73:050-001
Oceans
72-73:058-096
72-73:050-010
Oil Wells
72-73:088-010
Oil-Water Interfaces
72-73:088-010
Oilseed Crops
72-73:030-004
72-73:030-007
Oklahoma
72-73:020-003
72-73:03F-068
On-Site Investigations
72-73:03F-012
72-73:03F-064
On-Site Tests
72-73:026-097
72-73:02J-009
On-Site Tests
(Cont.)
72-73:03F-001
72-73:03F-019
72-73:03F-066
Open Channel Flow
72-73:04A-041
72-73:088-001
72-73:086-004
Open Channels
72-73:04A-006
72-73:086-002
72-73:088-004
Operations
72-73:04A-027
72-73:06A-004
Operations Research
72-73:02A-007
72-73:03F-007
Optimization
72-73:02F-059
72-73:038-001
72-73:03C-001
72-73:03F-002
72-73:03F-005
72-73:03F-006
72-73:03F-007
72-73:03F-017
72-73:03F-018
72-73:03F-021
72-73:04A-003
72-73:046-009
72-73:050-001
72-73:050-003
72-73:056-002
72-73:056-004
72-73:056-005
72-73:056-011
72-73:056-012
72-73:06A-001
72-73:06A-002
72-73:06A-003
72-73:06A-004
72-73:060-002
Optimum Development Plans
72-73:03F-013
72-73:03F-014
72-73:03F-020
72-73:046-010
Organic Acids
72-73:050-001
386
-------
Organic Compounds
72-73:05A-005
Organic Matter
72-73:02G-107
72-73:02G-112
72-73:020-129
72-73:020-136
72-73:020-137
72-73:020-165
72-73:056-057
72-73:050001
Organic Soils
72-73:04A-033
Organophosphorus Pesticides
72-73:050-010
Orifices
72-73:03F-042
Osmosis
72-73:020-023
Osmotic Pressure
72-73:020-186
72-73:020-195
72-73:03C-005
72-73:030-006
72-73:030-009
Outlets
72-73:03P-011
Overland Flow
72-73:020-152
72-73:05B-017
Oxidation
72-73:02F-055
72-73:020-098
72-73:030-005
72-73:030-009
72-73:056-049
72-73:05D-006
Oxidation Lagoons
72-73 :05D-013
Oxidation-Reduction Potential
72-73:020-098
72-73:050-002
Oxygen Demand
72-73:05B-096
Oxygen Sag
72-73:058-010
Oxygenation
72-73:020-190
Ozone
72-73:030-005
72-73:030-006
72-73:030-009
Pacific Northwest U.S.
72-73:020-002
Parametric Hydrology
72-73:02F-014
72-73:02F-025
72-73:058-068
72-73:06A-001
72-73:060-001
Particle Size
72-73:020-088
Pasture Management
72-73:04A-015
Pastures
72-73:020-186
72-73:021-020
72-73:04A-015
72-73:058-041
Path of
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
Pollutants
73:02F-017
73:02F-026
-73:02F-027
-73:02F-030
73:02F-031
73:02F-034
73:020-012
73:020-036
73:020-061
73:02K-001
7 3 :02K-004
73:05B-001
73:058-003
73:058-004
73:058-005
73:058-006
73:058-007
73:058-009
73:058-010
73:058-011
73:058-012
73:058-014
73:058-016
73:058-017
73:058-019
73:058-020
73:058-021
73:058-022
73:058-024
Path of Pollutants
(Cont.)
72-73:058-025
72-73:058-026
72-73:058-030
72-73:058-036
72-73:058-037
72-73:058-038
72-73:058-039
72-73:058-040
72-73:058-069
72-73:058-084
72-73:058-094
72-73:058-095
72-73:050-001
72-73:050-010
Pathogenic Bacteria
72-73:050-003
Peak Loads
72-73:03F-010
Peat
72-73:04A-033
72-73:058-052
Pecans
72-73:04A-051
Pennsylvania
72-73:02F-013
72-73:02K-006
Perched Water
72-73:020-198
Percolation
72-73:02F-023
72-73:020-007
72-73:020-012
72-73:020-013
72-73:020-040
72-73:020-042
72-73:020-058
72-73:020-060
72-73:020-061
72-73:020-080
72-73:020-082
72-73:620-088
72-73:020-114
72-73:03F-001
72-73:03F-019
72-73:03F-034
72-73:048-008
72-73:048-012
72-73:048-013
72-73:058-016
72-73:058-017
72-73:058-028
387
-------
Permeability
72-73S02F-008
72-73:02F-012
72-73:02F-015
72-73:02F-018
72-73:02F-019
72-73:02F-020
72-73J02F-022
72-73:02F-039
72-73:02F-046
72-73.-02F-052
72-73:02F-053
72-73:020-007
72-73:020-022
72-73:020-024
72-73:020-037
72-73:020-040
72-73:020-042
72-73:020-058
72-73:020-075
72-73:020-088
72-73:020-134
72-73:020-165
72-73:020-170
72-73-.03F-012
72-73:04A-001
72-73-.04A-004
72-73:04A-036
72-73:046-001
Perraeameters
72-73:02F-045
Persistence
72-73:058-094
Pesticide Kinetics
72-73:05B-065
Pesticide Residues
72-73:05B-004
72-73:050-010
Pesticides
72-73:053-008
72-73:058-022
72-73:05B-062
72-73:050-010
72-73:050-001
Phenols
72-73:050010
Phosphates
72-73:020-055
72-73:020-126
72-73:020-141
72-73:020-143
72-73:05A-002
72-73:058-005
Phosphates
(Cont.)
72-73:05B-020
72-73-.05B-029
72-73:05B-030
72-73:05B-064
72-73:056-069
72-73:058-095
72-73:05B-096
72-73.-05C-001
72-73:050-013
Phosphorus
72-73:02E-OI1
72-73:020-055
72-73:020-136
72-73:020-142
72-73:020-143
72-73:026-176
72-73:020-178
72-73:020-182
72-73:02G-185
72-73:020-205
72-73:02G-228
72-73:02J-013
72-73:03F-026
72-73:05B-029
72-73:058-041
72-73s05B-042
72-73:058-045(Page 291)
72-73:058-047
72-73:058-052
72-73:058-056
72-73:058-064
72-73s058-075
72-73:058-079
72-73:058-082
72-73:058-091
72-73:058-095
72-73:058-096
72-73:050-001
Phosphorus Compounds
72-73:050-005
Phosphothioate Pesticides
72-73:050-010
Photosynthes is
72-73:021-017
72-73:050-001
Phreatic Lines
72-73:04A-036
Phreatophytes
72-73.-02D-002
72-73:020-028
Physical Properties
72-73:020-003
Physiological Ecology
72-73:030-003
Piezometers
72-73:02F-019
72-73:02F-049
72-73:02F-068
72-73:058-018
Pine Trees
72-73:02F-043
Pipe Flow
72-73:03F-042
72-73:04A-023
72-73-.04A-037
72-73:04A-073
72-73:088-005
72-73:088-006
Pipelines
72-73:04A-039
72-73:050-001
72-73:088-005
72-73:088-011
Pipes
72-73:02F-062
72-73:03F-051
72-73.-04A-023
Plankton
72-73:050-002
Planning
72-73:020-009
72-73:03F-005
72-73:03F-010
72-73:03F-014
72-73:03F-046
72-73:03F-067
72-73:04A-003
72-73:058-015
72-73:050-001
72-73:06A-002
72-^3:06A-003
72-73:060-002
Plant Breeding
72-73:030-008
Plant Groupings
72-73:021-020
Plant Growth
72-73:02A-006
72-73:020-169
388
-------
Plant Growth
(Cont.)
72-73:021-004
72-73:021-009
72-73:021-012
72-73:021-018
72-73:030-005
72-73:030008
72-73:030-009
72-73:03F-023
72-73:03F-030
72-73:03F-031
72-73:03F-065
Plant Growth Regulators
72-73:02D-013
72-73:03F-025
72-73:03F-026
72-73:03F-027
72-73:03F-031
Plant Morphology
72-73:03F-023
Plant Physiology
72-73:020-056
72-73:021-012
72-73:021-017
72-73:030-003
72-73:030-004
72-73:030-008
72-73:03F-023
72-73:07B-002
Plant Populations
72-73:021-004
72-73:03F-027
72-73:04A-066
72-73:058-079
Plant Tissues
72-73:021-012
72-73:021-015
72-73:021-019
Plants
72-73:03F-018
Planting Management
72-73:021-010
72-73:03F-031
72-73:03F-052
72-73:03F-055
Plastic Pipes
(Cont.)
72-73:086-007
72-73:086-011
Plastics
72-73:020-198
Political Aspects
72-73:03F-009
Pollutant Identification
72-73:05A-001
72-73:05A-002
72-73:05A-005
72-73:058-037
72-73:050-003
Pollutants
72-73:02E-011
72-73:02F-074
72-73:020-124
72-73:020-211
72-73:058-023
72-73:058-024
72-73:058-058
72-73:058-064
72-73:058-065
Pollution Abatement
72-73:050-001
72-73:050-002
Pollution Sources
72-73:05E-001
Pollution Taxes (Charges)
72-73:053-002
72-73:050-005
72-73:050-012
Polymers
72-73:03E-001
Ponding
72-73:03F-001
72-73:03F-019
Ponds
72-73:050-010
Pore Pressure
72-73:02F-068
Pores
72-73:02F-016
72-73:02F-039
72-73:020-010
72-73:020-058
72-73:020-064
Porosity
72-73:02F-008
72-73:02F-016
72-73:02F-039
72-73:020-040
72-73:020-058
72-73:020-170
72---3:020-198
72-73:04A-034
Porous Media
72-73:02F-005
72-73:02F-016
72-73:02F-017
72-73:02F-031
72-73:02F-032
72-73:02F-035
72-73:02F-036
72-73:02F-039
72-73:02F-045
72-73:02F-047
72-73:02F-058
72-73:020-014
72-73:020-062
72-73:020-078
72-73:020-082
72-73:020-150
72-73:020-167
72-73:04A-034
72-73:058-022
72-73:056-025
72-73:058-084
72-73:088-010
Potassium
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
020-021
020-123
020-145
020-178
020-182
020-185
03F-025
058-041
058-042
058-047
058-052
Plastic Deformation
72-73:02F-062
72-73:086-011
Plastic Pipes
72-73:02F-062
Pore Water
72-73:02F-068
72-73:020-099
72-73:020-198
72-73:02J-003
72-73:058-059
Potatoes
72-73:020-202
72-73:04A-065
Potential Evapotranspiration
72-73:02D-006
389
-------
Potential Evapotranspiration
(Cont.)
72-73:02D-010
Potential Flow
72-73S02F-080
72-73:02G-092
Poultry
72-73:05B-095
Prairie Soils
72-73:058-045{Page 291)
Precipitation (Atmospheric)
72-73s02A-006
72-73:026-001
72-73:020-027
72-73:02E-004
72-73:02F-038
72-73:02F-055
72-73:03F-027
72-73:03F-031
72-73:048-008
72-73:050-010
Precipitation Excess
72-73:020-152
Precipitation Gages
72-73:026-029
Pressure
72-73:02F-007
72-73:02G-064
72-73:021-014
72-73:021-015
Pressure Conduits
72-73:088-006
Pressure Head
72-73:026-080
72-73:026-096
Pressure Measuring
Instruments
72-73:026-045
72-73:021-014
72-73:021-015
Pricing
72-73:056-005
72-73:060-002
Primary Productivity
72-73s05C-001
Prior Appropriation
72-73:048-007
Prior Appropriation
(Cont.)
72-73:06E-001
72-73:06E-002
Probability
72-73:020-007
72-73:020-009
Productivity
72-73:03F-010
Profit
72-73:03F-046
Programming Languages
72-73:07C-001
Project Planning
72-73:03F-017
Proteins
72-73:026-136
72-73:03F-025
72-73:03F-026
Provenance
72-73:02K-005
Pseudomonas
72-73:05C-002
72-73:050-014
Public Health
72-73:05C-010
Pumping
72-73:048-001
72-73:048-011
72-73:060-001
Pumps
72-73:03F-068
Radioactive Waste
Disposal
72-73:058-011
Radioactive Wastes
72-73:058-011
Radioactivity
72-73:02F-004
72-73:02J-Oll
72-73:08C-001
Radioactivity Technique!
72-73:026-079
72-73:026-084
Radioisotopes
72-73:02F-004
72-73:026-226
72-73:02K-004
72-73:05B-037
72-73:056-043
72-73:058-053
72-73:058-054
72-73:058-072
Rain
72-73:05C-010
Rainfall
72-73:026-219
72-73:02J-001
72-73:03F-005
72-73:03F-020
72-73:03F-025
72-73:03F-064
Rainfall Intensity
72-73:026-006
72-73:026-152
Rainfall Simulators
72-73:02J-009
Rainfall-Runoff Relationships
72-73:02A-001
72-73:02A-002
72-73:020-004
72-73:02F-021
72-73:026-006
72-73:026-152
72-73:02J-009
72-73:058-017
72-73:058-056
72-73:07C-001
Range Grasses
72-73:021-020
Range Management
72-73:040-001
Ranges
72-73:021-020
Rates of Application
72-73:03F-001
72-73:03F-019
72-73:03F-066
72-73:04A-012
72-73:04A-081
Recession Curves
72-73:02A-004
72-73:02E-008
390
-------
Recharge
72-73:02A-004
72-73:02F-023
72-73:02F-040
72-73:02F-042
72-73:02F-043
72-73:02F-053
72-73:02F-056
72-73:02F-080
72-73:020-012
72-73:026-024
72-73:020-062
72-73:04A-006
72-73:048-016
Recharge Wells
72-73:02F-027
72-73:02F-050
72-73:02F-066
72-73:046-003
Reclamation
72-73:02G-211
72-73:03F-013
Recreation Demand
72-73:04D-001
Reflectance
72-73:021-017
72-73:10A-003
Reduction (Chemical)
72-73:020-098
72-73:020-107
72-73:05B-049
72-73:05D-006
Regional Analysis
72-73:056-013
72-73:05D-003
72-73:050-004
72-73:06A-002
Regions
72-73:060-002
Regression Analysis
72-73:02E-002
72-73:020-021
72-73:020-082
72-73:020-177
72-73:02J-006
72-73:04A-002
72-73:058-009
72-73:058-013
72-73:058-019
Regulation
72-73:050-006
Remote Control
72~73:04A-023
Remote Sensing
72-73:020-157
72-73:078-002
72-73:10A-003
Repairing
72-73:04A-005
Research and Development
72-73:03F-046
Research Priorities
72-73:060-001
Reservoir Evaporation
72-73:020-016
72-73:03C-002
Reservoir Leakage
72-73:03E-001
Reservoir Operation
72-73:02E-002
Reservoir Releases
72-73:04A-003
Reservoir Silting
72-73:02J-005
Reservoir Yield
72-73:02E-004
Reservoirs
72-73:03F-004
72-73:03F-006
72-73:03F-021
72-73:040-001
72-73:050-003
72-73:06A-004
72-73:060-002
Resource Allocation
72-73:050-005
72-73:06A-002
72-73:060-002
Respiration
72-73:05C-002
Retention
72-73:02F-061
72-73:020-088
Return Flow
(Cont.)
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
72-73:
03F-016
03F-054
04B-005
048-007
04C-001
05B-016
05B-038
058-083
05B-094
050-001
050-013
050-015
050-016
Reverse Osmosis
72-73:050-014
Reviews
72-73:02F-001
72.-73:04B-002
72-73:058-008
72-73:05C-001
72-73:05C-002
72-73:050-014
72-73:050-015
Reynolds Number
72-73:02F-005
72-73:02F-039
72-73:088-007
Rice
72-73:020-109
72-73:020-183
72-73:020-188
72-73:021-008
Rill Erosion
72-73:02E-007
Rio Grande River
72-73:02E-006
Riparian Rights
72-73:06E-005
Risks
72-73:02F-059
72-73:03F-018
72-73:03F-020
72-73:040-001
River Basins
72-73:04A-003
72-73:050-001
72-73:050-002
72-73:06A-003
72-73:06A-004
391
-------
River Flow
72-73:04D-001
72-73:058-087
River Systems
72-73:058-087
Rivers
72-73:02J-001
72-73:058-096
72-73:05C-010
Roads
72-73:058-014
Root Development
72-73:02G-190
72-73:026-197
72-73:021-013
72-73:03F-027
72-73:03F-031
72-73:03F-065
72-73:050-009
Root Distribution,
72-73:020-190
72-73:026-192
72-73:026-199
72-73:021-009
72-73:03F-022
Root Systems
72-73:026-071
72-73:026-110
72-73:026-111
72-73:026-169
72-73:026-197
72-73:026-199
72-73:021-009
72-73:03F-023
72-73:03F-065
72-73:04A-005
72-73:05C-009
Root Zone
72-73:026-033
72-73:026-071
72-73:026-190
72-73:026-192
72-73:026-199
72-73:03F-003
72-73:03F-009
72-73:03F-064
72-73:048-008
72-73:050-009
72-73:080-001
Rotations
72-73:026-181
72-73:03F-003
Rots
72-73:03F-007
Roughness (Hydraulic)
72-73:02F-022
72-73:04A-028
72-73:088-004
72-73:088-007
Routing
72-73:02E-002
72-73:02E-003
72-73:02F-021
72-73:070-001
Rubber
72-73:04A-040
Runoff
72-73:020-005
72-73:020-027
72-73:02E-004
72-73:02E-012
72-73:02E-013
72-73:026-031
72-73:026-154
72-73:026-170
72-73:02J-001
72-73:02J-002
72-73:02J-009
72-73:02J-010
72-73:02J-013
72-73:03F-054
72-73:04A-069
72-73:040-003
72-73:058-004
72-73:058-017
72-73:058-020
72-73:058-027
72-73:058-045(Page 291)
72-73:058-047
72-73:058-052
72-73:058-062
72-73:058-067
72-73:058-5-091
72-73:058-095
72-73:050-010
72-73:050-007
72-73:050-008
Rural Areas
72-73:060-003
Safe Yield
72-73:02F-028
72-73:02F-J061
Sagebrush
72-73:020-005
Saline Soils
72-73:026-019
72-73:026-056
72-73:026-095
72-73:026-107
72-73:026-108
72-73:026-134
72-73:026-141
72-73:026-144
72-73:026-145
72-73:026-184
72-73:026-212
72-73:02J-003
72-73:02K-002
72-73:030-003
72-73:030-004
72-73:030-006
72-73:03F-001
72-73:03F-019
72-73:03F-034
72-73:03F-066
72-73:04A-084
Saline Water
72-73:02F-030
72-73:026-002
72-73:026-087
72-73:026-095
72-73:026-184
72-73:02K-002
72-73:030-002
72-73:030-008
72-73:04A-084
72-73:048-030
72-73:050-005
Saline Water Intrusion
72-73:02F-017
72-73:02F-028
72-73:02F-030
72-73:02F-031
72-73:02F-034
72-73:048-002
72-73:048-030
72-73:058-026
72-73:056-003
Saline Water Systems
72-73:026-019
72-73:048-002
Saline Water-Freshwater
Interfaces
72-73:02F-017
72-73:02F-028
72-73:026-086
72-73:048-030
72-73:058-025
392
-------
Salinity
72
72
72
72
72
72
72
72
72
72
72
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72.
72-
72-
72
72
72
72
72
72
72
72
72
27
72
72
72
72
72
72
72
72
72
72-
72-
72-
72-
72-
72-
72-
72-
72-
-73:020-001
1-73:020-036
-73:02E-014
-73:02F-031
73:02F-071
73:02F-077
73:020-016
73:020-041
73:020-059
73:020-087
-73:020-101
73:020-103
73:020-105
73:020-107
73:020-108
73:020-112
73:020-115
73:020-117
73:020-120
73:020-122
73:020-123
73:020-124
-73:020-127
73:020-130
73:020-141
73:020-144
73:020-145
73:020-179
-73:020-184
-73:020-186
73:020-187
-73:020-188
-73:020-189
-73:020-190
-73:020-192
-73:020-195
-73:020-209
-73:020-212
-73:020-214
-73:020-220
-73:03A-001
-73:030-001
-73:030002
-73:030-003
-73:030-004
-73:030-005
-73:030-006
-73:030-007
-73:030-008
-73:030-009
73:03F-001
73:03F-002
73:03F-018
73:03F-019
73:03F-066
73:04A-002
73:04A-005
73:04A-018
73:04A-084
Salinity
(Cont.)
72-73:
72-73
72-73:
72-73
72-73
72-73
72-73
72-73
72-73
72-73
72-73
72-73
72-73
72-73
72-73
:04A-085
:04B-030
:05B-014
:05B-027
:05B-032
:05B-038
:05B-043
:05B-044
:05B-046
: 050-009
:050-001
:05G-003
:050-013
:05G-015
:050-016
Salt Balance
72-73:02K-002
72-73:03C-002
72-73:03F-056
72-73:03F-066
72-73:04A-084
72-73:04A-085
72-73:05B-032
72-73:050-008
Salt Tolerance
72-73:020-056
72-73:030-003
72-73:030-004
72-73:030-006
72-73:030-008
Saltation
72-73:048-030
Salts
72-73:020-019
72-73:020-058
72-73:020-086
72-73:020-089
72-73:020-122
72-73:020-144
72-73:030-002
72-73:04B-030
72-73:040-001
72-73:058-014
72-73:056-027
72-73:05B-038
Sampling
72-73:02E-012
72-73:02F-043
72-73:02F-071
72-73:020-008
72-73:020-083
72-73:02J-004
72-73:02J-010
Sampling
(Cont.)
72-73:05A-001
72-73:05A-002
72-73:05A-004
72-73:056-013
72-73:076-001
Sands
72-73:020-014
72-73:020-015
72-73:02F-023
72-73:03F-060 .
Sanitary Engineering
72-73:056-092
72-73:058-093
72-73:050-009
Saturated Flow
72-73:02A-001
72-73:02A-005
72-73:02F-012
72-73:02F-016
72-73:02F-017
72-73:02F-018
72-73:02F-020
72-73:02F-028
72-73:02F-029
72-73:02F-035
72-73:02F-058
72-73:020-011
72-73:020-013
72-73:020-015
72-73:020-017
72-73:020-025
72-73:020-062
72-73:020-168
72-73:04A-001
72-73:04A-032
72-73:046-012
72-73:048-013
72 7-73:058-021
Saturated Soils
72-73:020-096
72-73:020-150
Saturation
72-73t02K-009
Scheduling
72-73:02A-007
72-73:020-020
72-73:03F-014
72-73:04A-049
Scour
72-73:02J-007
393
-------
Screens
72-73s05D-011
Sea Ice
72-73:020001
Sea Water
72-73:06B-001
Sealants
72-73-.03E-Q01
Seasonal
72-73:02J-001
72-73:03F-006
72-73:03F-026
72-73:03F-027
72-73:03F-031
Secondary Productivity
72-73:050-001
Sediment Control
72-73:02J-007
72-73:02J-008
72-73:05B-003
72-73:05G-006
72-73:088-003
Sediment Discharge
72-73:02J-001
72-73:02J-005
72-73:050-006
Sediment Load
72-73:02E-007
72-73:02J-004
72-73:05B-003
72-73:088-003
Sediment Sorting
72-73:02J-010
Sediment Transport
72-73:02E-007
72-73:02J-002
72-73:02J-007
72-73:02J-011
72-73:050-001
Sediment Yield
72-73:02D-005
72-73:02E-007
72-73:02J-001
72-73:02J-002
72-7 3-.02 J-005
72-73:02J-006
72-73:02J-010
72-73:058-003
Sediment Yield
(Cont.)
72-73:058-030
72-73s088-003
Sediment-Water Interfaces
72-73:058-008
72-73:050-001
72-73:050-002
Sedimentation
72-73:02E-007
72-73:02J-005
72-73:02J-006
72-73:02J-007
72-73:02J-011
72-73:02J-012
72-73:04D-001
72-73:050-001
72-73:050-003
72-73:050-006
72-73:088-003
Sedimentation Rates
72-73:020-056
Sediments
72-73:02E-011
72-73i02H-001
72-73:02J-007
72-73:05A-002
72-73:058-002
72-73:058-004
72-73:058-008
72-73:058-058
72-73:058-096
72-73:050-001
72-73:050-002
72-73:088-003
Seeds
72-73:030-007
72-73:03F-030
Seepage
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
73:02F-026
73:02F-056
73:02F-068
73:02F-069
73:02F-079
73:020-003
73:020-015
73:020-072
73:020-080
73:020-086
73:020-091
-73:020-109
73:020-150
73:03E-001
Seepage
(Cont.)
72-73:04A-004
72-73:04A-032
72-73:04A-034
72-73:04A-036
72-73:048-016
72-73:050-010
72-73:088-002
Seepage Control
72-73:03E-001
72-73:04A-036
Semiarid Climates
72-73:02D-002
72-73:020-013
72-73:030-008
72-73-.03F-011
72-73:03F-025
72-73 .-03F-026
72-73:03F-027
Separable Costs
72-73:050-003
Separation Techniques
72-73:050-003
Septic Tanks
72-73:058-028
72-73:058-040
Settling Basins
72-73:02J-007
Sewage Bacteria
72-73:050-009
Sewage Disposal
72-73:04A-037
72-73:058-006
72-73:050-008
72-73:05E-001
Sewage Effluents
72-73:05A-005
72-73:050-008
Sewage Lagoons
72-73:050-010
Sewage Treatment
72-73:050-008
72-73:050-009
72-73:050-010
72-73:050-011
72-73:050-012
72-73:05E-001
394
-------
Shallow Water
72-73s05D-002
72-73:060-001
Sheep
72-73:053-095
Sheet Erosion
72-73J02E-007
72-73:02J-006
72-73:05B-030
Shrinkage
72-73:020-024
Silting
72-73s04A-005
Silts
72-73:026-096
Simulated Rainfall
72-73:02J-009
Simulation Analysis
72-73:02A-002
72-73:02A-003
72-73:02A-007
72-73:020-004
72-73:02E-002
72-73:02F-015
72-73:02F-040
72-73:02G-023
72-73:021-002
72-73:02K-003
72-73:03F-004
72-73:03F-006
72-73:03F-Ol4
72-73:03F-020
72-73:03F-021
72-73:048-010
72-73:053-015
72-73:053-016
72-73:050-002
72-73:06A-001
72-73:06A-003
72-73:063-001
72-73:083-011
Sinks
72-73:050-001
Siphons
72-73:04A-055
Sites
72-73:03F-015
Slope Stabilization
72-73:020-072
Slopes
72-73:02F-072
72-73:03F-003
72-73:03F-011
Sluices
72-73:02j-007
Snow
72-73:05A-005
Snow Removal
72-73:053-014
Social Aspects
72-73:03F-016
Social Values
72-73.-03F-016
Sodium
72-73:020-112
72-73:020-144
72-73:02J-003
72-73-.03A-001
72-73:030-007
72-73:03F-034
72-73:053-016
72-73:050-008
Sodium Chloride
72-73:030-007
Soil Aggregates
72-73:020-176
Soil Amendments
72-73:020-027
72-73:020-165
72-73:053-023
72-73:053-049
Soil Analysis
72-73:020-115
72-73:02K-010
72-73:053-032
Soil Asphalt
72-73:020-033
Soil Bacteria
72-73:02F-055
Soil Cement
72-73:020-162
Soil Chemical Properties
72-73:020-013
72-73:020-074
72-73-.02G-130
Soil Chemical Properties
(Cont.)
72-73:020-143
72-73:030-006
72-73:053-032
Soil Chemistry
72-73:020-025
72-73:020-001
72-73:020-018
72-73:020-019
72-73:020-020
72-73:020-027
72-73:020-041
72-73:020-055
72-73:020-077
72-37:020-098
72-73:020-102
72-73:020-107
72-73:020-108
72-73:020-112
72-73:020-115
72-73:020-141
72-73:020-142
72-73:020-144
72-73:020-172
72-73:020-225
72-73:020-228
72-73:02J-003
72-73:02K-008
72-73:02K-011
72-73:04A-084
72-73:04A-085
72-73:04C-001
72-73:053-051
72-73:053-058
72-73:053-065
Soil Compaction
72-73:020-035
72-73:080-003
Soil Conservation
72-73:020-026
72-73:02E-007
72-73:02J-008
72-73:02J-012
72-73:02J-013
72-73:02J-014
72-73:03F-001
72-73 .-03F-019
72-73:03F-054
72-73:03F-055
72-73:040-003
72-73:060-001
Soil Density
72-73:020-084
72-73:020-165
72-73:080-003
395
-------
Soil Density Probes
72-73:02G-084
Soil Disposal Fields
72-73:05B-028
72-73:058-039
72-73:058-040
Soil Environment
72-73:026-041
72-73:030-004
72-73:073-002
Soil Erosion
72-73:02E-007
72-73:02E-012
72-73:02J-003
72-73:02J-005
72-73:02,1-006
72-73:02J-008
72-73:02J-009
72-73:02J-014
72-73:040-002
72-73:05B-003
72-73:058-030
72-73:050-001
Soil Filters
72-73:050-008
Soil Formation
72-73:026-095
Soil Gases
72-73:02K-005
Soil Groups
72-73:026-012
Soil Horizons
72-73:026-025
72-73:080-003
Soil Investigations
72-73:026-056
72-73:026-115
72-73:043-008
72-73:058-051
72-73:078-002
Soil Management
72-73:02E-011
72-73:026-027
72-73:026-039
72-73:026-041
72-73:026-134
72-73:026-162
72-73:026-165
72-73:026-176
72-73:03F-055
Soil Management
(Cont.)
72-73:03F-066
72-73:048-008
72-73:080001
Soil Mechanics
72-73:026-046
Soil Microorganisms
72-73:058-060
Soil Moisture
72-73:02A-006
72-73:020-002
72-73:020-005
72-73:020-010
72-73:020-020
72-73:020-021
72-73:020-024
72-73:020-031
72-73:020-034
72-73:020-037
72-73:02F-043
72-73:02F-076
72-73:026-008
72-73:026-017
72-73:026-018
72-73:026-020
72-73:026-026
72-73:026-033
72-73:026-037
72-73:026-040
72-73:026-041
72-73:026-042
72-73:026-045
72-73:026-047
72-73:026-078
72-73:026-083
72-73:026-090
72-73:026-093
72-73:026-096
72-73:026-118
72-73:026-127
72-73:026-148
72-73:026-156
72-73:026-157
72-73:026-158
72-73:026-169
72-73:026-170
72-73:026-172
72-73:026-174
72-73:026-175
72-73:026-187
72-73:026-188
72-73:026-189
72-73:026-191
72-73:026-194
72-73:026-196
72-73:026-197
Soil Moisture
(Cont.)
72-73:026-198
72-73:026-201
72-73:026-202
72-73:026-203
72-73:026-204
72-73:026-206
72-73:026-207
72-73:026-210
72-73:026-213
72-73:026-222
72-73:026-223
72-73:021-003
72-73:021-005
72-73:021-019
72 3:03F-006
72-73:03F-007
72-73:03F-010
72-73:03F-013
72-73:03F-014
72-73:03F-018
72-73:03F-020
72-73:03F-026
72-73:03F-030
72-73:03F-031
72-73:03F-064
72-73:03F-071
72-73:03F-072
72-73:03F-073
72-73:04A-025
72-73:04A-044
72-73:04A-078
72-73:04A-080
72-73:048-008
72-73:056-015
Soil Moisture Meters
72-73:026-045
72-73:026-059
72-73:026-079
72-73:026-081
72-73:026-084
72-73:026-092
72-73:026-104
72-73:026-148
72-73:048-008
Soil Physical Properties
72-73:026-022
72-73:026-024
72-73:026-025
72-73:026-042
72-73:026-060
72-73:02J-006
72-73:056-015
Soil Physics
72-73:02F-074
72-73:026-022
72-73:026-037
396
-------
Soil Physics
(Cont.)
72-73:02G-039
72-73:02G-040
72-73:02G-042
72-73:020-046
72-73:020-088
72-73:020-102
72-73:020-107
72-73:020-112
72-73:020-116
72-73:020-141
72-73:020-157
72-73:020-162
72-73:020-165
72-73:020-167
72-73:020-176
72-73:020-210
72-73:04A-012
72-73:04A-034
72-73:04A-085
72-73:05B-065
72-73:08D-003
Soil Profiles
72-73:020-027
72-73:03P-001
72-73s03F-019
72-73:04B-008
72-73:080001
72-73:080-003
Soil Properties
72-73:026-012
72-73:020-027
72-73:020-039
72-73:020-082
72-73:020-115
72-73:020-143
72-73:020-162
72-73:03F-001
72-73:03F-019
72-73:03F-067
72-73:053-065
72-73:050002
72-73:080-003
Soil Science
72-73:020-115
72-73:020-116
72-73:020-157
72-73:03F-023
Soil Sealants
72-73:03E-001
72-73:043-002
Soil Stability
72-73:020-162
72-73:040-002
Soil Sterilants
72-73:05B-060
Soil Structure
72-73:020-025
72-73:020-058
72-73:020-165
72-73:020-176
72-73:040-002
72-73:080-003
Soil Surfaces
72-73:020-034
72-73:020-035
72-73:020-162
72-73:07B-002
Soil Surveys
72-73:02G-022
Soil Temperature
72-73:020-091
72-73:020-092
72-73:03F-061
72-73:04A-065
72-73:078-002
Soil Tests
72-73:020-115
72-73:020-177
72-73:03F-023
Soil Texture
72-73:020-039
72-73:020-162
72-73:020-165
72-73:020-192
72-73:080-003
Soil Treatment
72-73:020-039
72-73:020-146
72-73:020-176
72-73:040-002
72-73:080001
Soil Types
72-73:020-034
72-73:020-056
72-73:020-088
72-73:03F-003
72-73:03F-008
72-73:05A-004
72-73.-08D-003
Soil Water
72-73:020-005
72-73:020-013
72-73:020-014
72-73:020-015
Soil Water
(Cont.)
72-73:020-018
72-73:020-024
72-73:020-025
72-73:020-031
72-73:020-034
72-73:02F-043
72-73:02F-055
72-73:02F-076
72-73:02F-080
72-73:02F-081
72-73:02F-082
72-73:02F-083
72-73:02G-002
72-73:020-008
72-73:020-017
72-73:020-037
72-73:020-040
72-73:020-045
72-73:02G-059
72-73:020-071
72-73:020-077
72-73:020-079
72-73:020-081
72-73:020-102
72-73:020-104
72-73:020-110
72-73:020-111
72-73:020-114
72-73:020-118
72-73:020-127
72-73:020-156
72-73:020-157
72-73:020-158
72-73:020-164
72-73:020-168
72-73:020-170
72-73:020-172
72-73:020-173
72-73:020-174
72-73:020-203
72-73:020-206
72-73:020-214
72-73:020-216
72-73:020-217
72-73:020-218
72-73:020-219
72-73:020-222
72-73:02K-005
72-73:030001
72-73:03F-023
72-73 .-03F-046
72-73:03F-061
72-73:056-039
72-73:050-016
72-73:10A-001
Soil Water Movement
72-73:02A-002
397
-------
Soil Water Movement
(Cont.)
72-73:02A-005
72-73:020-023
72-73:02D-024
72-73:020-025
72-73:02E-016
72-73:02F-035
72-73:02F-057
72-73:02F-075
72-73:02F-076
72-73:020-001
72-73:02G-003
72-73:020-004
72-73:026-006
72-73:020-007
72-73:020-009
72-73:020-010
72-73:020-011
72-73:020-012
72-73:020-013
72-73:020-014
72-73:020-015
72-73:020-017
72-73:020-018
72-73:020-019
72-73:020-020
72-73:020-022
72-73:020-023
72-73:020-024
72-73:020-034
72-73:020-035
72-73:020-040
72-73:020-042
72-73:020-045
72-73:020-056
72-73:020-057
72-73:020-058
72-73:020-060
72-73:020-061
72-73:020-062
72-73:020-063
72-73:020-064
72-73:020-071
72-73:020-075
72-73:020-076
72-73:020-078
72-73:020-080
72-73:020-082
72-73:020-083
72-73:020-086
72-73:020-087
72-73:020-088
72-73:020-089
72-73:020-090
72-73:020-091
72-73t020-092
72-73:020-093
72-73:020-094
72-73:020-095
Soil Water Movement
(Cont.)
72-73:020-096
72-73:020-097
72-73:020-099
72-73:020-100
72-73:020-110
72-73:020-111
72-73:020-114
72-73:020-128
72-73:020-131
72-73:020-151
72-73:020-152
72-73:020-158
72-73:020-159
72-73:020-166
72-73:020-203
72-73:020-210
72-73:020-212
72-73:020-216
72-73:020-217
72-73:020-218
72-73:020-219
72-73:020-222
72-73:02K-004
72-73:03F-001
72-73:03F-008
72-73:03F-009
72-73:03F-012
72-73s03F-019
72-73:03F-023
72-73:04A-030
72-73:04A-035
72-73:046-008
72-73:056-001
72-73:053-011
72-73:05B-017
Soil-Water-Plant Relation-
ships
72-73:02A-006
72-73:020-007
72-73:020-013
72-73:020-021
72-73:020-031
72-73:020-041
72-73:020-071
72-73:020-092
72-73:020-110
72-73:020-111
72-73:020-169
72-73:020-172
72-73:020-187
72-73:021-003
72-73:030-003
72-73:030-004
72-73:03F-010
72-73:03F-023
72-73:03F-026
72-73:03F-027
Soil-Water-Plant
Relationships
72-73:03F-028
72-73:03F-030
72-73:03F-064
72-73:03F-065
72-73:04A-085
72-73:046-008
72-73:058-024
72-73:076-002
Soils
72-73:020-017
72-73:020-019
72-73:020-027
72-73:020-067
72-73i02G-096
72-73:020-211
72-73:03F-015
72-73:03F-023
72-73:03F-024
72-73:03F-029
72-73:03F-028
72-73:03F-065
72-73:03F-067
72-73:04A-075
72-73:05A-004
72-73:056-029
72-73:056-051
72-73:050-010
72-73:076-003
72-73:078-004
72-73:080-003
Solar Radiation
72-73:020-030
72-73:020-035
72-73:03F-024
Solid Wastes
72-73:058-057
72-73:058-093
72-73:050-012
Solubility
72-73:020-055
72-73:020-077
72-73:020-098
72-73:020-225
72-73:02K-001
72-73:02K-009
72-73:02K-011
72-73:058-058
72-73:058-069
72-73:058-083
Solutes
72-73:02F-017
72-73:02F-045
72-73:020-002
398
-------
Solutes
(Cont.)
72-73:020-036
72-73:020-077
72-73:026-127
72-73:05B-021
72-73:053-083
Solvents
72-73:02K-009
Sorghum
72-73:02D-001
72-73:021-013
72-73:021-014
72-73:03F-063
Sorption
72-73:05C-001
South Carolina
72-73:020-043
Southwest U.S.
72-73:030-003
72-73:04A-002
72-73:04A-003
Soybeans
72-73:02D-010
72-73:020-179
72-73:020-185
72-73:020-207
72-73:021-013
72-73:03F-023
72-73:03F-024
Spatial Distribution
72-73:03F-056
Specific Capacity
72-73:02F-044
72-73:043-006
Specific Conductivity
72-73:020-108
Specific Yield
72-73:02F-061
Specifications
72-73:083-011
Spectrophotometry
72-73:020-148
72-73:02K-001
Spillways
72-73:03F-011
Spring
72-73:03F-026
72-73s03F-031
Spring Waters
72-73:02F-077
Springs
72-73:02F-013
72-73:02F-042
72-73:02F-077
Sprinkler Irrigation
72-73:02D-033
72-73:02D-036
72-73:020-029
72-73:020-116
72-73:020-162
72-73:03F-002
72-73:03F-003
72-73:03F-009
72-73:03F-051
72-73:03F-052
72-73:03F-056
72-73:03F-057
72-73:03F-064
72-73:03F-066
72-73:04A-015
72-73:04A-020
72-73:04A-029
72-73:04A-037
72-73:04A-048
72-73:04A-051
72-73i04A-052
72-73:04A-053
72-73:04A-054
72-73:04A-063
72-73:04A-065
72-73:04A-066
72-73:04A-071
72-73:04A-074
72-73:04A-076
72-73:04A-077
72-73:04A-081
72-73:04A-082
72-73:053-063
72-73:050-002
72-73S08B-005
72-73:083-007
Sprinkling
72-73:020-033
72-73:03F-001
72-73:03F-019
72-73:04A-020
Stable Isotopes
72-73:020-135
72-73:02K-005
72-73:053-061
Stage-Discharge Relations
72-73:07C-001
Standards
72-73:050-001
Standing Waters
72-73:073-002
State Jurisdiction
72-73:06E-001
Statistical Methods
72-73:02A-005
72-73:020-007
72-73:02F-041
72-73:02F-051
72-73:02F-057
72-73:020-076
72-73:02J-006
72-73:053-013
72-73:053-019
72-73:053-068
Statistical Models
72-73:02A-003
72-73:02A-005
72-73:03C-001
72-73:04A-002
72-73:053-009
Statistics
72-73:020-003
72-73:020-007
72-73:020-009
72-73:02F-038
72-73:02F-051
72-73:02J-006
72-73:02K-006
72-73:053-019
Steady Flow
72-73:02F-028
72-73:020-005
72-73:020-078
72-73:020-095
72-73:020-096
72-73:020-097
72-73:03F-012
Stochastic Processes
72-73 :02A-003
72-73:03F-004
72-73:03F-005
72-73:03F-017
72-73:03F-020
72-73:03F-021
72-73:043-010
72-73:040-001
72-73:050-011
399
-------
Stokes Law
72-73:02F-005
Stomata
72-73:02D-021
72-73:021-012
Storage
72-73:02F-012
72-73:050-010
Storage Coefficient
72-73:02F-003
72-73:02F-011
72-73:02F-012
72-73:02F-018
72-73:02F-020
72-73:02F-025
72-73:02F-048
72-73:04B-001
Storm Runoff
72-73:02fl-002
72-73:05A-002
Strain
72-73:02F-058
Stratification
72-73:020-060
72-73t05B-014
Stratified Flow
72-73J02F-017
72-73:02F-027
72-73:02F-031
Stream Gages
72-73:020-001
Streamflow
72-73:020-001
72-73:02J-007
72-73:03F-005
72-73:03F-018
72-73:04A-002
72-73:04D-001
72-73:058-019
Streamflow Forecasting
72-73:02A-003
72-73:02E-002
Streams
72-73:02J-007
72-73:058-064
72-73:050-010
72-73:088-003
Streptococcus
72-73:050-003
Stress
72-73:02F-058
72-73:02G-187
72-73:02G-188
72-73:02G-189
72-73:020-193
72-73:020-202
72-73:020-207
72-73:03F-071
72-73:03F-072
72-73:04A-040
Subcritical Flow
72-73:088-001
Subhumid Climates
72-73:02D-017
Submergence
72-73:05F-003
Subsidence
72-73:02F-001
72-73:02F-036
Subsoil
72-73:020-121
Subsurface Drainage
72-73:02F-061
72-73:02F-075
72-73:020-005
72-73:020-030
72-73:020-043
72-73:020-072
72-73:020-103
72-73:020-105
72-73:020-139
72-73:020-159
72-73:020-160
72-73:020-161
72-73:020-166
72-73:020-171
72-73:020-212
72-73:020-214
72-73:020-215
72-73:020-216
72-73:020-217
72-73:020-218
72-73:020-220
72-73:03F-066
72-73:04A-005
72-73:04A-035
72-73:058-020
72-73:058-036
Subsurface Drains
72-73:02F-062
72-73:03F-012
72-73:04A-035
72-73:088-007
Subsurface Flow
72-73t02A-002
72-73:02F-041
72-73:050-015
Subsurface Irrigation
72-73:02F-021
72-73:026-078
72-73:020-131
72-73:020-163
72-73:020-166
72-73:020-210
72-73:020-221
72-73:020-222
72-73:03F-012
72-73:03F-063
Subsurface Runoff
72-73:02A-002
72-73:02F-021
72-73:058-052
72-73:058-062
Suburban Areas
72-73:058-014
Sugar Beets
72-73:020-176
72-73:020-191
72-73:020-194
72-73:030-003
72-73:03F-027
Sugar Crops
72-73:030-003
Sugarcane
72-73:020-166
72-73:020-221
72-73:04A-072
Sulfates
72-73:020-077
72-73:05A-004
72-73:058-016
72-73:058-081
72-73:058-088
Sulfur
72-73:058-081
Sulfur Compounds
72-73:058-081
400
-------
Supplemental Irrigation
72-73t02D-020
72-73:020-208
72-73:04A-051
Surface Drainage
72-73:020-212
72-73:020-214
72-73:020-215
72-73:020-216
72-73:020-217
72-73:020-218
72-73:020-219
Surface Flow
72-73:050-015
Surface Irrigation
72-73:02D-033
72-73:02E-008
72-73:020-046
72-73:020-163
72-73:020-174
72-73:020-175
72-73:020-223
72-73:03F-051
72-73:03F-052
72-73:03F-053
72-73:03F-057
72-73:03F-063
72-73:03F-066
72-73:04A-008
72-73:04A-021
72-73:04A-025
72-73:04A-028
72-73:04A-029
72-73t04A-039
72-73:04A-042
72-73:04A-043
72-73:04A-044
72-73:04A-051
72-73:04A-052
72-73:04A-054
72-73:04A-055
72-73:04A-056
72-73:04A-057
72-73:04A-058
72-73:04A-059
72-73:04A-060
72-73:04A-061
72-73-.04A-062
72-73:04A-063
72-73:04A-064
72-73:04A-065
72-73:04A-068
72-73:04A-069
72-73:04A-070
72-73:04A-073
72-73:04A-074
72-73:04A-075
Surface Irrigation
(Cont.)
72-73:04A-076
72-73:04A-077
72-73:04A-078
72-73s04A-081
72-73:04A-082
72-73:04A-082
72-73:05B-063
Surface Runoff
72-73:02E-008
72-73:02E-012
72-73:03F-003
72-73:03F-047
72-73:03F-068
72-73S04D-001
72-73:056-052
72-73:053-056
72-73s058-062
72-73:050-003
Surface Sealing
72-73:020-035
Surface Water Availability
72-73:043-009
Surface Waters
72-73:02A-001
72-73:02A-008
72-73:02A-010
72-73:02E-004
72-73:02K-001
72-73:04A-002
72-73:048-009
72-73:05B-005
72-73:05B-013
72-73:07B-002
Surface-Groundwater
Relationships
72-73:02A-001
72-73:02A-002
72-73:02A-004
72-73:02A-008
72-73:02A-010
72-73:02D-014
72-73:020-015
72-73:02F-023
72-73:02F-033
72-73:02F-053
72-73:02F-056
72-73:02F-066
72-73:02F-078
72-73:04A-006
72-73:048-004
72-73:04B-007
72-73:04B-010
72-73:058-017
Surface-Groundwater
Relationships
(Cont.)
72-73:088-002
Surveys
72-73:04A-045
72-7 3:04 A-046
72-73:050-003
72-73 .-10A-003
Suspended Load
72-73:02E-012
72-73:02J-004
72-73:056-030
Suspended Solids
72-73:02J-010
Suspension
72-73:02J-010
Swamps
72-73:050-010
Switch Grass
72-73:021-020
Synthetic Hydrology
72-73:02A-003
72-73:02A-007
72-73:020-004
Systems
72
72
72
72
72
72
72
72
72
72
72.
72
72
72
72.
72-
72.
72
72-
72-
72-
72-
72-
72-
72
72
Analysis
-73:02A-007
-73:020-004
-73:02F-025
-73:02F-059
-73:02G-211
-73:030-001
-73:03F-004
-73:03F-005
-73:03F-006
-73:03F-014
-73:03F-017
-73:03F-018
-73:03F-020
-73:03F-021
-73s04A-003
-73:04B-009
-73:040-001
-73:058-015
-73:058-068
-73:050-001
-73:050-003
-73:050-002
-73.-05G-004
-73:050-005
-73:050-011
-73:050-015
401
-------
Systems Analysis
(Cont.)
72-73:06A-001
72-73:06A-002
72-73:06A-003
72-73:06A-004
72-73:066-001
72-73:06D-001
72-73:06D-002
72-73:070-001
Tailwater
72-73:03F-047
72-73:03F-054
Temperature
72-73:02D-001
72-73:020-008
72-73:02D-016
72-73:02D-033
72-73:020-091
72-73:02G-092
72-73:020-096
72-73:020-227
72-73:03C-003
72-73:03F-025
72-73:04A-030
72-73:058-084
72-73:05B-092
Temperature Control
72-73:020-033
Tensiometers
72-73:02F-068
72-73:02F-076
72-73:020-045
72-73:020-118
72-73:020-175
72-73:020-196
72-73:020-203.
72-73:020-206
72-73:03F-007
Tension
72-73:020-045
72-73:020-196
72-73:020-198
72-73:020-201
72-73:020-204
Test Wells
72-73:02F-006
Testing Procedures
72-73:03F-002
Texas
72-73:02D-001
72-73:04B-003
Texas
(Cont.)
72-73:043-005
72-73:048-020
72-73:058-013
72-73:058-015
72-73:06E-005
Thawing
72-73:058-092
Theis Equation
72-73:02F-048
Theoretical Analysis
72-73:020-004
72-73:03F-012
72-73:050-012
Thermal Insulation
72-73:020-227
Thermal Pollution
72-73:058-089
Thermal Powerplants
72-73:058-089
Thermal Radiation
72-73:078-002
Thermal Springs
72-73:02F-077
Thermal Stress
72-73:03C-003
72-73:078-002
Thermodynamics
72-73:020-016
72-73:020-126
Thermometers
72-73:020-091
72-73:020-092
Thiems Equation
72-73:02F-044
Thin Films
72-73:020-032
Tile Drainage
72-73:02F-071
72-73:02F-075
72-73:020-005
72-73:020-043
72-73:020-072
72-73:020-103
72-73:020-105
Tile Drainage
(Cont.)
72-73:020-139
72-73:020-159
72-73:020-160
72-73:020-161
72-73:020-166
72-73:020-171
72-73:020-212
72-73:020-214
72-73:020-215
72-73:020-216
72-73:020-217
72-73:020-218
72-73:020-220
72-73:04A-005
72-73:05F-003
Tile Drains
72-73:02F-062
72-73:02F-079
72-73:020-005
72-73:04A-005
72-73:058-029
72-73:058-084
72-73:088-007
Tiles
72-73:02F-062
72-73:020-030
72-73:04A-001
Time
72-73:03F-065
Time Series Analysis
72-73:02A-003
72-73:02F-038
72-73:058-019
Timing
72-73:04A-079
72-73:04A-080
Tomatoes
72-73:020-179
72-73:020-199
Topography
72-73:020-008
Topsoil
72-73:020-143
Toxicity
72-73:020-122
72-73:05C-010
Trace Elements
72-73:020-016
402
-------
Trace Elements
(Cont.)
72-73:020-018
72-73:02G-020
72-73:020-098
72-73:020-102
72-73:020-122
72-73:02K-001
72-73:05A-001
Tracers
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
7 3:02P-004
-73:02F-041
73:02F-042
-73:02P-043
73:02F-055
73:02F-078
73:020-018
73:020-020
73:020-024
73 :020-05 8
73:020-063
73:020-086
73:02K-004
73:02K-005
73:058-018
73:05B-037
73:078-001
Tracking Techniques
72-73:02K-004
72-73:073-001
Transition Flow
72-73:02F-069
72-73:02F-079
72-73:020-118
Translocation
72-73:02F-047
72-73:020-086
72-73:020-099
72-73:05B-011
72-73:05B-021
72-73:058-025
Transmissivity
72-73:02A-004
72-73:02F-002
72-73:02F-003
72-73:02F-007
72-73:02F-011
72-73:02F-025
72-73:02F-035
72-73:02F-037
72-73:02F-044
7.2-73:04A-001
72-73:048-001
72-73:048-006
72-73:058-018
Transpiration
72-73:02D-001
72-73:02D-002
72-73:020-017
72-73:020-018
72-73:020-019
72-73:020-071
72-73:020-197
72-73:021-008
72-73:021-012
Tra nsporta t ion
72-73:050-009
Travertine
72-73:04A-005
Treatment Facilities
72-73:050-003
72-73:050-011
Trenches
72-73:020-004
72-73:020-171
Triazine Pesticides
72-73:056-094
Tritium
72-73:02F-042
72-73:02F-043
72-73:02F-055
72-73:020-024
73-73:020-086
Tunneling Machines
72-73:020-031
Turbidity
72-73:058-003
Turbulence
72-73:02E-001
72-73:088-007
Turbulent Flow
72-73:02F-022
Turnouts
72-73:04A-023
Underflow
72-73:020-014
72-73:020-015
Underground Waste Disposal
72-73:02F-084
Uniform Plow
72-73:04A-028
Uniformity Coefficient
72-73:020-029
72-73:03F-009
72-73:04A-020
72-73:04A-068
72-73:04A-070
72-73:04A-071
72-73:04A-073
United States
72-73:02E-006
72-73:02J-001
72-73:060-002
Unsaturated Flow
72-73:02A-001
72-73:02A-005
72-73:02F-012
72-73:02F-016
72-73:02F-017
72-73:02F-018
72-73:02F-020
72-73:02F-035
72-73:02F-048
72-73:02F-080
72-73:020-007
72-73:020-009
72-73:020-010
72-73:020-011
72-73:020-008
72-73:020-013
72-73:020-014
72-73:020-015
72-73:020-017
72-73:020-023
72-73:020-025
72-73:020-035
72-73:020-036
72-73:020-045
72-73:020-061
72-73:020-062
72-73:020-075
72-73:020-076
72-73:020-078
72-73:020-080
72-73:020-083
72-73:020-087
72-73:020-088
72-73:020-096
72-73:020-097
72-73:020-128
72-73:020-150
72-73:020-158
72-73:020-168
72-73:020-227
72-73:04A-001
72-73:04A-021
72-73:04A-032
72-73:048-008
72-73:048-012
403
-------
Unsaturaged Flow
(Cont.)
72-73:04B-013
72-73:05B-001
72-73:058-040
72-73:056-050
Unsteady
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
72-
Flow
73:02A-001
73:02F-010
73:02F-011
73:02F-012
73:02E-001
73:02E-002
73:02F-015
73:02F-029
73:02F-033
73:02F-048
73:02F-050
73t02F-058
73:020-014
73:026-015
73:020-036
73:020-045
73:020-083
73:020-128
73:04B-006
73:048-012
73:04B-013
73:04B-014
73:048-015
Urban Hydrology
72-73:058-014
Urbanization
72-73:058-003
72-73:060-002
Urea Pesticides
72-73:058-094
Utah
72-73:020-056
72-73:050-016
Valleys
72-73:020-008
Value
72-73:03F-021
Valves
72-73:04A-023
Vapor Pressure
72-73:020-016
Variability
72-73:02A-005
Variability
(Cont.)
72-73:020-007
72-73:020-009
72-73:02F-032
72-73:02F-038
72-73:02F-041
72-73:03F-021
72-73:03F-026
72-73:058-013
72-73:058-019
Varieties
72-73:030-004
Vegetable Crops
72-73:03F-007
72-73:03F-056
Vegetation
72-73:03F-031
72-73:058-045(Page 291)
Vegetation Effects
72-73:020-005
72-73:02F-043
72-73:02J-005
7,2-73:02J-006
72-73:02K-002
Velocity
72-73:02J-007
72-73:03F-003
Viability
72-73:03C-004
Viscosity
72-73:02F-005
72-73:02F-022
Waste Disposal
72-73:02F-084
72-73:058-006
72-73:050-007
72-73:050-005
Waste Disposal Wells
72-73:02F-084
Waste Storage
72-73:02F-084
Waste Treatment
72-73:050-005
72-73:050-007
72-73:050-012
Waste Water (Ppllution)
72-73:050-014
Waste Water Disposal
72-73:02F-084
72-73:050-002
72-73:050-008
72-73:05E-001
Waste Water Treatment
72-73:05A-004
72-73:050-001
72-73:050-002
72-73:050-003
72-73:050-013
72-73:050-014
72-73:050-002
72-73:050-012
Water
72-73:020-033
72-73:02E-008
72-73:020-137
72-73:03F-046
Water Allocation (Policy)
72-73:04A-025
72-73:06E-002
Water Analysis
72-73:02K-001
72-73:02K-006
72-73:05A-001
72-73:05A-005
72-73:058-076
72-73:05C-003
Water Balance
72-73:02A-001
72-73:020-001
72-73:020-002
72-73:020-004
72-73:020-005
72-73:020-017
72-73:020-027
72-73:02F-023
72-73:02F-042
72-73:02F-038
72-73:02F-041
72-73:02F-043
72-73:02F-051
72-73:02F-056
72-73:020-047
72-73:02J-002
72-73:02K-002
72-73:03F-005
72-73:048-004
Water Chemistry
72-73:020-025
72-73:02F-004
72-73:02F-013
72-73:02F-045
404
-------
Water Chemistry
(Cont.)
72-73:020-002
72-73:02G-016
72-73:02G-077
72-73:026-089
72-73:020-108
72-73:020-117
72-73:020-220
72-73:02J-002
72-73:02K-001
72-73:02K-002
72-73:02K-003
72-73:02K-004
72-73:02K-005
72-73:02K-006
72-73:02K-008
72-73:02K-011
72-73:04A-002
72-73:04C-001
72-73-.05A-001
72-73:056-003
72-73:05B-013
72-73:05B-021
72-73:05B-025
72-73:058-076
Water Conservation
72-73:02D-021
72-73:02D-026
72-73:02D-032
72-73:02J-008
72-73:02J-012
72-73:02J-014
72-73:038-001
72-73.-03P-030
72-73:03F-053
72-73:03P-054
72-73:03F-061
72-73:03F-062
72-73:03F-068
72-73:048-005
72-73:04D-003
72-73:050-001
72-73:060-001
Water Consumption (Except
Consumptive Use)
72-73:03F-006
Water Control
72-73:04A-072
Water Costs
72-73:03F-Ol8
72-73:06A-001
Water Delivery
72-73:03F-039
72-73:04A-025
Water Demand
72-7 3 .-020-047
72-73:03F-004
72-73:03F-005
72-73:03F-006
72-73:03F-018
72-73:03F-027
72-73:03F-030
72-73:03F-031
72-73:04A-003
72-73:04A-025
72-73:060-001
72-73:060-002
Water Distribution (Applied)
72-73:026-047
72-73:03F-003
72-73:03F-013
72-73:03F-042
72-73:03F-050
72-73:03F-051
72-73:03F-067
72-73:04A-025
72-73:04A-027
72-73:04A-028
72-73:04A-037
72-73:04A-039
72-73:04A-072
72-73:06A-004
72-73:088-006
Water Flow
72-73:02E-008
Water Law
72-73:03F-016
72-73:048-020
72-73:06E-002
72-73:06E-003
72-73:0673-005
Water Level Fluctuations
72-73:02A-002
72-73:02A-004
72-73:020-002
72-73:02F-008
72-73-.02F-012
72-73-.02F-018
72-73:02F-020
72-73.-02F-038
72-73:02F-048
72-73:02F-051
72-73:02F-053
72-73:020-005
72-73:048-012
72-73:048-013
Water Levels
72-73:02F-006
72-73:02F-014
Water Levels
(Cont.)
72-73 .-02F-015
72-73:04A-033
72-73:048-002
72-73:048-005
72-73:048-011
Water Loss
72-73:020-002
72-73:020-003
72-73:020-014
72-73:020-015
72-73:020-024
72-73:020-026
72-73:020-028
72-73:020-029
72-73:020-032
72-73:020-031
72-73:020-071
72-73:026-164
72-73:03E-001
72-73:03F-060
72-73:04A-032
72-73:078-002
Water Management (Applied)
72-73:02A-008
72-73:02A-010
72-73:02E-002
72-73:02E-006
72-73:026-215
72-73:021-007
72-73:038-001
72-73:03F-002
72-73:03F-016
72-73:03F-020
72-73:03F-030
72-73:03F-057
72-73:03F-060
72-73:04A-027
72-73:04A-038
72-73:048-005
72-73:048-010
72-73:058-016
72-73:058-017
72-73:058-032
72-73:050-015
72-73:06A-001
72-73:06A-002
72-73:06A-005
Water Measurement
72-73:04A-041
72-73:088-001
Water Policy
72-73:03F-016
405
-------
Water Policy
72-73:03F-016
Water Pollution
72-73:02F-074
72-73:030-002
72-73:04B-030
72-73:05B-003
72-73:05B-007
72-73:058-009
72-73:05B-016
72-73:056-023
72-73:056-038
72-73:056-064
72-73:05B-065
72-73:05B-087
72-73:05C-003
72-73:05C-010
72-73:050-003
Water Pollution Control
72-73:05A-002
72-73:05B-007
72-73:058-056
72-73:058-067
72-73:056-084
72-73:058-095
72-73:056-096
72-73:050-006
72-73:05(3-012
Water Pollution Effects
72-73:030-005
72-73:030-009
72-73:058-003
72-73:058-005
72-73:058-009
72-73:056-096
72-73:050-003
72-73:050-010
72-73:056-013
Water Pollution Sources
72-73:02E-013
72-73:02E-014
72-73:020-109
72-73:020-124
72-73:020-133
72-73:020-135
72-73:020-135
72-73:020-181
72-73:021-007
72-73:02J-013
72-73:02J-011
72-73:02K-001
72-73:02K-002
72-73:02K-007
72-73:048-002
72-73:040-001
72-73:040-003
Water Pollution Sources
(Cont.)
72-73:05A-002
72-73:058-002
72-73:058-004
72-73:058-005
72-73:058-007
72-73:058-008
72-73:058-009
72-73:058-014
72-73:058-017
72-73:058-020
72-73:058-022
72-73:058-023
72-73:056-027
72-73:056-029
72-73:058-030
72-73:058-032
72-73:058-034
72-73:058-038
72-73:058-039
72-73:058-041
72-73:058-042
72-73:058-043
72-73:058-044
72-73:058-045(Page 291)
72-73i058-046
72-73:056-047
72-73:058-048
72-73:058-049
72-73:058-050
72-73:058-052
72-73:058-053
72-73:058-054
72-73:056-056
72-73:056-059
72-73:056-060
72-73:056-062
72-73:056-063
72-73i056-064
72-73:058-067
72-73:056-069
72-73:056-071
72-73:058-075
72-73:056-076
72-73:056-080
72-73:056-081
72-73:056-085
72-73:056-086
72-73:056-088
72-73:056-089
72-73:056-091
72-73:056-094
72-73:058-095
72-73:056-096
72-73:050-010
72-73:050-007
72-73:050-008
72-73:050-009
72-73:050-010
Water Pollution Sources
(Cont.)
72-73:050-014
72-73:05F-003
72-73:05F-004
72-73:050-006
72-73:050-012
72-73:050-013
Water Pollution Treatment
72-73:050-005
72-73:050-006
72-73:050-014
Water Properties
72-73:020-002
Water Quality
72-73:02E-012
72-73.-02E-013
72-73:02E-014
72-73:02F-027
72-73:020-114
72-73:020-124
72-73:020-211
72-73:020-220
72-73:02J-012
72-73:02K-002
72-73:03A-001
72-73:030-001
72-73:04A-002
72-73:048-003
72-73:048-009
72-73:048-030
72-73:040-001
72-73:040-004
72-73:05A-001
72-73:058-002
72-73:058-003
72-73:058-005
72-73:058-006
72-73:058-007
72-73:058-013
72-73:058-015
72-73:058-016
72-73:058-017
72-73:058-019
72-73:058-023
72-73:058-031
72-73:058-034
72-73:058-036
72-73:058-038
72-73:056-068
72-73:056-076
72-73:058-087
72-73:058-093
72-73:050-002
72-73:050-003
72-73:050-002
72-73:050-007
406
-------
Water Quality
(Cont.)
72-73:050-009
72-73:05F-004
72-73:050-003
72-73:050-005
72-73:050-016
72-73:06E-001
Water Quality Control
72-73:02F-074
72-73:03P-016
72-73:048-005
72-73:05A-002
72-73:05B-087
72-73:058-094
72-73:05D-001
72-73:050-005
72-73:050-013
72-73:050-001
72-73:050-002
72-7 3:050-004
72-73:050-011
72-73:050-012
72-73:050-013
Water Quality Standards
72-73:050-005
72-73:050-011
Water Rates
72-73:03F-031
Water Requirements
72-73:020-021
72-73:020-047
72-73:020-153
72-73:020-202
72-73:03F-039
72-73:03F-052
72-73:03F-064
72-73:03F-065
72-73:03F-067
72-73:04A-025
72-7 3:04A-085
72-73:06A-005
Water Resources
72-73:03F-013
72-73:03F.-014
72-73:03F-017
72-73:03F-018
72-73:03F-046
72-73:056-005
72-73:050-015
72-73:06A-002
72-73:068-001
Water Resources Development
(Cont.)
72-73:03F-021
72-73:048-003
72-73:048-010
Water Reuse
72-73:03F-068
72-73:04A-027
72-73:048-005
72-73:050-002
72-73:050-013
Water Rights
72-73:03F-018
72-73:03F-016
72-73:048-007
72-73:048-020
72-73:06E-001
72-73:06E-002
72-73:06E-005
Water Sampling
72-73:020-109
72-73:058-020
Water Shortage
72-73:03C-008
72-73:03F-018
Water Spreading
72-73:020-034
72-73:020-062
72-73:048-003
Water Storage
72-73:02F-007
72-73:02F-010
72-73:02E-008
72-73:02F-027
72-73:048-003
Water Supply
72-73:02E-014
72-73:03F-004
72-73:03F-005
72-73:03F-006
72-73:03F-014
72-73:03F-031
72-73:03F-067
72-73:04A-003
72-73:04A-039
72-73:048-020
72-73:060-002
Water Supply Development
72-73:040-003
Water Resources Development
72-73:02A-008
Water Table
72-73:020-029
72-73:02F-001
72-73:02F-012
72-73:02F-018
72-73:02F-020
72-73:02F-033
72-73:02F-040
72-73:02F-068
72-73:020-005
72-73:020-155
72-73:020-173
72-73:020-212
72-73:020-214
72-73:020-219
72-73:03F-012
72-73:03F-023
72-?3:04A-001
72-73:04A-033
72-73:048-001
72-73:048-005
72-73:048-009
73-73:048-011
72-73:048-014
72-73:060-001
Water Table Aquifers
72-73:050-002
Water Temperature
72-73:02A-003
72-73:020-014
72-73:020-015
72-73:020-002
72-73:020-091
72-73:020-092
72-73:05C-002
72-73:05C-003
72-73:050-004
Water Transfer
72-73:021-008
72-73:02F-006
Water Treatment
72-73:048-009
72-73:050-005
72-73:050-013
72-73:05F-004
Water Types
72-73:02F-077
72-73:058-076
Water Users
72-73:020-129
Water Utilization
72-73:02A-008
72-73:02A-010
407
-------
Water Utilization
(Cont.)
72-73:02D-013
72-73:028-001
72-73:02D-038
72-73:02F-073
72-73:020-163
72-73:020-169
72-73:020-202
72-73:020-224
72-73:021-005
72-73:021-008
72-73:021-009
72-73:021-012
72-73:021-013
72-73:030-002
72-73:030008
72-73:03P-003
72-73:03P-025
72-73:03F-027
72-73:03P-031
72-73:03F-065
72-73:048-020
72-73:06A-005
72-73:06E-003
72-73:06E-004
72-73:06E-005
72-73:10A-002
Water Vapor
72-73:02B-001
72-73:020-026
Water Wells
72-73:02P-001
72-73:02F-029
72-73:02P-051
72-73:048-014
72-73:06E-005
72-73:088-010
Water Yield
72-73:02P-002
72-73:02F-007
72-73:02F-014
72-73:02F-015
72-73:02F-023
72-73:02F-029
72-73:02F-044
72-73:02F-048
72-73:02P-049
72-73:02F-052
72-73:02F-066
72-73:02F-072
72-73:02J-001
72-73:02J-002
72-73:048-001
72-73:048-005
72-73:048-008
72-73:048-012
Water Yield
(Cont.)
72-73:048-013
72-73:048-014
72-73:06E-005
Water Yield Improvement
72-73:02D-005
72-73:038-001
72-73:04A-033
Waterproofing
72-73:04A-040
72-73:040-002
Watershed Management
72-73:02J-005
72-73:038-001
72-73:048-008
72-73:040-001
72-73:040-004
72-73:058-023
Watersheds (Basins)
72-73:02E-004
72-73:020-056
72-73:058-023
72-73:058-024
Weathering
72-73:020-094
72-73:02K-003
72-73:04A-040
Weed Control
72-73:058-065
72-73:058-071
72-73:058-094
Weight
72-73:020-031
72-73:020-164
72-73:03F-031
Weirs
72-73:04A-004
Wells
72-73:02F-067
72-73:03F-005
wetlands
72-73:050-003
Wettability
72-73:040-002
Wetting
72-73:020-006
72-73:020-010
Wetting
(Cont.)
72-73:020-011
72-73:020-013
72-73:020-014
72-73:020-025
72-73:020-034
72-73:020-035
72-73:020-060
72-73:020-064
72-73:020-075
72-73:020-082
72-73:020-128
72-73:040-002
Wheat
72-73:020-032
72-73:020-129
72-73:020-136
72-73:020-187
72-73:020-200
72-73:020-227
72-73:021-003
72-73:021-015
72-73:03F-026
72-73:03F-073
72-73:058-077
Wheatgrasses
72-73:021-020
Wildlife
72-73:040-001
72-73:05C-010
Wilting
72-73:020-013
72-73:020-018
Wind Velocity
72-73:03F-025
72-73:03F-063
Winds
72-73:020-001
72-73:020-003
. 72-73:020-006
72-73:020-008
72-73:020-016
Wisconsin
72-73:03F-067
Withdrawal
72-73:02F-001
72-73:02F-011
72-73:02F-028
72-73:02F-030
72-73:02F-049
72-73:048-002
408
-------
Withdrawal
(Cont.)
72-73:04B-012
72-73:04B-013
72-73:043-014
X-Ray Analysis
72-73:05A-001
X-Ray Fluorescence
72-73:05A-001
Xylem
72-73:021-014
72-73:021-015
Yeasts
72-73:05C-001
Yield
72-73:021-011
Yield Equations
72-73:028-001
72-73:02D-038
72-73:026-177
72-73:026-195
72-73:021-002
72-73:021-004
72-73:03P-062
72-73:05B-082
Zinc
72-73:026-228
72-73:02K-001
72-73:05A-004
Zinc Radioisotopes
72-73:026-018
72-73:026-020
Zone of Aeration
72-73:026-008
72-73:026-075
Zoning
72-73:06D-003
2,4-D
72-73:05B-094
72-73:050-010
2,4,5-T
72-73:05B-065
72-73:056-094
72-73:050010
409
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
1-. Report No,
w
4 !-,.Ğ SELECTED IRRIGATION RETURN FLOW QUALITY
ABSTRACTS 1972-1973,
> v^tv.s. Skogerboe, G.V. , Walker, W.R., Bennett, R.S.
and Zakely, B.J.
Agricultural Engineering Department, Colorado State
University, Fort Collins, Colorado 80521
S. Report .;IMtei''r
6,
js, -'.p'>rt'oHniBg Or
. Rcpiuf No',
R-800426
32,
EPA/ office of Research and Develbpmi
Environmental Protection Agency report number EPA-660/2-74-049.
June 1974
Research related to the quality of irrigation return flow is being con-
ducted at numerous institutions throughout the western United States.
Related work is also underway at other institutions in the United
States, as well as other portions of the world. Approximately 100
sources of material have been searched for articles pertinent to the
National Irrigation Return Flow Research and Development Program. These
articles describe water quality problems resulting from irrigated agri-
culture, potential technological solutions for controlling return flows,
recent research pertinent to return flow investigations, and literature
associated with institutional constraints in irrigation return flow
quality control.
This third annual issue of SELECTED IRRIGATION RETURN FLOW QUALITY
ABSTRACTS covers publications printed in 1972 and 1973. This report was
submitted in fulfillment of Grant Number R-800426 under the sponsorship
of the Office of Research and Monitoring, Environmental Protection Agency
a*
stn.n-r-i Fertilizers, Irrigated land, Irrigated systems, Irrigation
water, Nitrates, Phosphates, Return flow, Salinity, Water pollution
effects, Water pollution sources, Water quality control.
17b
\\-ht & G-obp 05G
1 - .. '". iy. Secnriiv Class.
(Repw!)
20. Security. Class.
(Page)
Gaylord V. Skog^rhrt<=.
21. "No, of
i'agss .
22. !'ru;c
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. OJC. 2024O
Colorado State University
ĞU.S. GOVERNMENT PRINTING OFFICE:1974 546-319/441 1-3
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