EPA-600/2-77-094
May 1977
Environmental Protection Technology Series
SELECTED IRRIGATION RETURN FLOW
QUALITY ABSTRACTS, 1975
Robert S. Kerr Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Ada, Oklahoma 74320
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental 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.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-77-094
May 1977
SELECTED IRRIGATION RETURN FLOW
QUALITY ABSTRACTS 1975
Fifth Annual Issue
by
Gaylord V. Skogerboe
Stephen W. Smith
Wynn R. Walker
Colorado State University
Fort Collins, Colorado 80523
Grant No. R-800426
Project Officer
James P. Law, Jr.
Robert S. Kerr Environmental Research Laboratory
Ada, Oklahoma 74820
ROBERT S. KERR ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
ADA, OKLAHOMA 74820
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DISCLAIMER
This report has been reviewed by the Office of Research
and Development, U.S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the
U.S. Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or
recommendation for use.
11
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FOREWORD
The fifth annual issue of SELECTED IRRIGATION RETURN
FLOW QUALITY ABSTRACTS has been compiled from approximately
100 sources of material covering calendar year 1975. This
compilation has attempted to include technological and insti-
tutional 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 Pollu-
tion Problems of Irrigation Return Flow" prepared by the Utah
State University Foundation contains a bibliography of articles
pertinent to Irrigation Return Flow Quality through 1967. 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 contained abstracts of articles and reports published
during calendar years 1972 and 1973, and the fourth annual is-
sue contains abstracts of 1974 publications. The fifth annual
issue contains 501 abstracts of documents published during
calendar year 1975. The abstracts have been placed into sec-
tions 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."
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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 Re-
turn 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 investi-
gations, 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, the third annual issue covers calendar years
1972 and 1973, and the fourth annual issue covers literature
published in 1974. This annual issue lists publications printed
in 1975. This report was submitted in fulfillment of Grant
Number R-800426 under the sponsorship of the Office of Research
and Development, Environmental Protection Agency.
Key Words: Fertilizers, Irrigated Land, Irrigation Sys-
tems, Irrigation Water, Nitrates, Phosphates, Return Flow,
Salinity, Water Pollution Effects, Water Pollution Sources,
Water Quality Control.
IV
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TABLE OF CONTENTS
Foreword iii
Abstract iv
Acknowledgment . vii
I WATER CYCLE - General (Group 02A) 1
II WATER CYCLE - Precipitation (Group 02B) 3
III WATER CYCLE - Snow, Ice, and Frost (Group 02C) 4
IV WATER CYCLE - Evaporation and Transpiration
(Group 02D) 5
V WATER CYCLE - Streamflow and Runoff (Group 02E) 11
VI WATER CYCLE - Groundwater (Group 02F) 13
VII WATER CYCLE - Water in Soils (Group 02G) 28
VIII WATER CYCLE - Lakes (Group 02H) 73
IX WATER CYCLE - Water in Plants (Group 021) 74
X WATER CYCLE - Erosion and Sedimentation
(Group 02J) 78
XI WATER CYCLE - Chemical Processes (Group 02K).. 85
XII WATER CYCLE - Estuaries (Group 02L) 92
XIII WATER SUPPLY AUGMENTATION AND CONSERVATION -
Water Yield Improvement (Group 03B) 93
XIV WATER SUPPLY AUGMENTATION AND CONSERVATION -
Use of Water of Impaired Quality (Group 03C).. 96
XV WATER SUPPLY AUGMENTATION AND CONSERVATION -
Conservation in Agriculture (Group 03F) 100
XVI WATER QUANTITY MANAGEMENT AND CONTROL -
Control of Water on the Surface (Group 04A) .. 129
XVII WATER QUANTITY MANAGEMENT AND CONTROL -
Groundwater Management (Group 04B) 134
XVIII WATER QUANTITY MANAGEMENT AND CONTROL -
Effects on Water of Man's Nonwater Activities
(Group 04C) 140
XIX WATER QUANTITY MANAGEMENT AND CONTROL -
Watershed Protection (Group 04D) 141
XX WATER QUALITY MANAGEMENT AND PROTECTION -
Identification of Pollutants (Group 05A) 142
XXI WATER QUALITY MANAGEMENT AND PROTECTION -
Sources and Fate of Pollution (Group 05B) .... 148
XXII WATER QUALITY MANAGEMENT AND PROTECTION -
Effects of Pollution (Group 05C) 171
XXIII WATER QUALITY MANAGEMENT AND PROTECTION -
Waste Treatment Processes (Group 05D) 174
v
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TABLE OF CONTENTS (Cont'd)
XXIV WATER QUALITY MANAGEMENT AND PROTECTION -
Ultimate Disposal of Wastes (Group 05E) 175
XXV WATER QUALITY MANAGEMENT AND PROTECTION -
Water Treatment and Distribution (Group 05G)... 177
XXVI WATER QUALITY MANAGEMENT AND PROTECTION -
Water Quality Control (Group 05G) 178
XXVII WATER RESOURCES PLANNING - Techniques of
Planning (Group 06A) 189
XXVIII WATER RESOURCES PLANNING - Cost Allocation,
Cost Sharing, Pricing/Repayment (Group 06C).... 190
XXIX WATER RESOURCES PLANNING - Water Law and
Institutions (Group 06E) 191
XXX WATER RESOURCES PLANNING - Ecologic Impact of
Water Development (Group 06G) 192
XXXI RESOURCES DATA - Data Acquisition (Group 07B).. 193
XXXII RESOURCES DATA - Evaluation, Processing and
Publication (Group 07C) 194
XXXIII ENGINEERING WORKS - Structures (Group 08A) 195
XXXIV ENGINEERING WORKS - Hydraulics (Group 08B) 196
XXXV ENGINEERING WORKS - Soil Mechanics (Group 08D). 200
XXXVI ENGINEERING WORKS - Rock Mechanics and Geology
(Group 08E) 201
XXXVII ENGINEERING WORKS - Materials (Group 08G) 202
XXXVIII AUTHOR INDEX 203
XXXIX SUBJECT INDEX 216
VI
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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 accom-
plishing the work reported herein.
The efforts of Mrs. Debby Wilson and Ms. Carole Pflug in
preparing the necessary forms which are forwarded to the Water
Resources Scientific Information Center are sincerely appreci-
ated, as well as the typing of this final report.
The scope of this literature abstracting effort has been
delineated jointly by the senior author and the Project Officer,
Dr. James P. Law, Jr., Chief, Irrigated Agriculture Section,
Source Management Branch, Robert S. Kerr Environmental Research
Laboratory, Environmental Protection Agency, Ada, Oklahoma.
The cooperative efforts of the Project Officer in meeting with
project personnel and reviewing the abstracting process have
been very helpful and are sincerely appreciated.
via.
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Section I
WATER CYCLE
GENERAL (GROUP 02A)
75:02A-001
RAINFALL-INDUCED RUNOFF COMPUTED FOR FALLOW FIELDS,
Hauser, V.L., Hiler, E.A.
Agricultural Research Service, Durant, Oklahoma, Water Quality Management
Laboratory.
Transactions of American Society of Agricultural Engineers, Vol. 18, No. 1,
p 122-125, January-February 1975. 5 fig, 1 tab, 13 ref.
Descriptors: Hydrology, *Great Plains, *Agriculture, *Equations, *Rainfall-
runoff relationships, Runoff, Agricultural runoff, Surface runoff, Rainfall
intensity, Rainfall, Solar radiation, Sheet erosion, Suspended load, Texas,
Kansas, Iowa, Forecasting, *Runoff forecasting.
There are no long-term runoff records available that could be used to determine
the needed runoff amount of return-frequency information for the western Great
Plains; however, management of this water can increase yields. Rainfall amount
and intensity, runoff, and soil water were measured on 3 terraced fields for 12
years. The soil was clay loam and had a slowly permeable layer; the average
land slope was 1.5%. The fields were cropped in a wheat-sorghum-fallow sequence
which gave 22 months of fallow for each 36-month period. Stubble mulch tillage
was used to control wind and water erosion. A set of equations was developed to
compute rainfall-induced runoff from fallow land with the use of daily rainfall,
maximum 1-hr rainfall for the day, and computed soil water content. Equations
were computed for three conditions (1) soil water content greater than field
capacity, (2) fallow-after-wheat from June to January, and (3) fallow-after-sor-
ghum plus after wheat January to June. About 15% more runoff was computed than
was measured on a fallow period basis; however, a linear correction reduced the
error to 4.6%. The following conclusions were drawn from the study: (1) the
equations for soil water can be used to compute runoff from rainfall records; (2)
soil water content may be computed and used successfully in runoff equations;
(3) daily runoff can be computed accurately with inputs of daily rainfall, com-
puted soil water content, and maximum 1-hr rainfall for the day; and (4) the use
of computed soil water content permits the equation set to compute runoff for the
whole year.
75:02A-002
NUTRIENT AND SEDIMENT DISCHARGE FROM AGRICULTURAL WATERSHEDS IN OKLAHOMA,
Olness, A., Smith, S.J., Rhoades, E.D., and Menzel, R.G.
Agricultural Research Service, Durant, Oklahoma. Water Quality Management Lab.
Journal of Environmental Quality, Vol. 4, No. 3, p 331-336, July-September, 1975.
1 fig, 3 tab, 19 ref.
Descriptors: *Surface runoff, *Sediment yield, *Agricultural watersheds, *Nitro-
gen, *Phosphorus, *Ranges, Nutrients, Chemical analysis, Watershed management,
Cultivated lands, Fertilizers, Oklahoma, Soil erosion, Precipitation(Atmospheric),
Rainfall-runoff relationships, Runoff, Topsoil, Vegetation effects. Nitrates,
Grazing, Range management.
Seven cropland watersheds and four rangeland watersheds in central Oklahoma were
monitored for surface hydrology and discharge of nitrogen, phosphorus, and sedi-
ment over a 1 year period in which precipitation and runoff were much above normal.
Sediment losses from the continuancy grazed rangeland watersheds ranged from 18 to
23 metric tons/hectare during the study. None of the sediment losses from the
other watersheds exceeded 10 metric tons/hectare. Total nutrients discharged in
runoff ranged from 2 to 15 kilograms/hectare of N and 1 to 11.5 kilograms/hectare
of P. Flow-weighted mean concentrations ranged from 1 to 6 parts per million of
total N, 0.2 to 1.9 ppm of nitrate-N, 0.5 to 4.8 ppm of total P, and 0.04 to 9.9
ppm of soluble P. Cropland watersheds had much greater concentrations of soluble
phosphorus in runoff than rangeland watersheds. Loss of fertilizer N and P did
not exceed 5 percent of the most recent applications, even though surface runoff
was 4 to 10 times greater than that observed in previous years.
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75:02A-003
A COMBINED MODEL OF WATER TABLE AND RIVER STAGE EVOLUTION,
Morel-Seytoux, H.J.
Colorado State University, Fort Collins. Engineering Research Center.
Water Resources Research, Vol. 11, No. 6, p 968-972, December 1975. 29 ref.
Descriptors: *Surface-groundwater relationships, Streamflow, *Aquifer systers,
*Aquifer characteristics, *Groundwater movement, *Simulation analysis, *Model
studies, Aquifers, Pumping, Flood stages, Flood flow, Return flow, Hydrology,
Hydraulics, Momentum equation.
An integral equation was derived which completely characterizes the interaction
between a stream and the alluvial aquifer. Expressed in finite difference form,
the equation was of great practical utility in solving flooding problems (i.e.,
negligible effect of pumping on river flows) as it relates river stages to return
flows. It was also useful to solve pure conjunctive use of surface water and
groundwater problems (i.e., negligible river stage fluctuations) as it relates
return flows to pumping rates, or to solve composite problems. The numerical
procedures to calculate the response function coefficients in terms of the physi-
cal characteristics of the system were given in detail.
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Section II
WATER CYCLE
PRECIPITATION (GROUP 02B)
75:028-001
HYDROLOGIC IMPACT OF WEATHER MODIFICATION,
Seely, E.H., DeCoursey, D.G.
United States Department of Agriculture, Agricultural Research Service, P.O.
Box 400, Chickasha, OK 73018
Water Resources Bulletin, Vol. 11, No. 2, p 365-369, April 1975. 9 ref.
Descriptors: *Weather modification, *Hydrologic systems, Hydrology, Water
supply, Water supply development.
Weather modification is being proposed as a routine method of augmenting agri-
cultural water supplies in the Southern Great Plains. This paper discusses
some of the potential hydrologic impacts of weather modification. Previous work
in assessing hydrologic impact is covered; the conclusion is drawn that the
work is insufficient. An approach based on hydrologic models is suggested that
can consider uncertainties about the effect of weather modification on rainfall
and some uncertainties about the effect of model error on impact conclusions.
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Section III
WATER CYCLE
SNOW, ICE, AND FROST (GROUP 02C)
75:02C-001
OBSERVATIONS OF STAGE, DISCHARGE, PH, AND ELECTRICAL CONDUCTIVITY DURING PERIODS
OF ICE FORMATION IN A SMALL SUBARCTIC STREAM,
Osterkamp, T.E., Gilfilian, R.E., and Benson, C.S.
Alaska University, College. Geophysical Institute,.
Water Resources Research, Vol. 11, No. 2, p 268-272, April 1975. 6 fig,
16 ref.
Descriptors: *Ice, *Streamflow, *Electrical conductance, Conductivity, Frazil
ice, Freezing, Permafrost, Discharge(Water), Flow profiles, Discharge Measure-
ment, Water levels, Hydrogen ion concentration, *Subarctic, Streams, *Alaska.
Ice formation in a small subarctic stream modified the stage, velocity profiles,
discharge, and electrical conductivity, while the pH remained nearly constant.
Frazil ice crystals suspended in the flow reduced the velocity profiles and in-
creased the stage. Anchor ice and border ice growth decreased the discharge
by 31 and 55% for two periods of underwater ice production. These reductions in
discharge may be attributed to storage in the form of ice and to upstream water
storage caused by increased flow resistance in the stream. The increase in the
electrical conductivity of the stream water during periods of ice production was
related to the concentration of ice in the stream. Ice concentrations calculated
from this increase in conductivity were 1.8, 0.9, and 4.7% (by volume) for the
first 150 min of three different periods of ice production.
75:02C-002
COMPUTER SIMULATION OF THE SNOWMELT AND SOIL THERMAL REGIME AT BARROW, ALASKA,
Outcalt, S.I., Goodwin, C., Weller, G., Brown, J.
Michigan University, Ann Arbor. Department of Geography.
Water Resources Research, Vol. 11, No. 5, p 709-715, October 1975. 3 fig, 3 tab,
17 ref.
Descriptors: Computer models, *Snowmelt, *Soils, *Alaska, Tundra, Temperature,
Model studies, Water supply. Freshwater, Melt water, Snow, Arctic.
An annual snow-soil simulator for arctic tundra was developed by using coupled
models of surface equilibrium temperature and substrate thermal diffusion.
Snow ripening, melt, and accumulation were modeled in the simulator which was
forced with daily weather data. The simulator predicted that a snow fence array
capable of producing drift deeper than 4.2 m would initiate a permanent snowfield
at Barrow, Alaska. Such a man-induced snowfield could serve as a reliable source
of freshwater for Barrow and similar villages in the north slope region of
Alaska. Further analysis indicated that albedo reduction due to dust fall, snow
removal, etc., was dominant over aerodynamic effects in producing the early
spring meltout observed at Barrow Village.
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Section IV
WATER CYCLE
EVAPORATION AND TRANSPIRATION (GROUP 02D)
75:020-001
SIMULATION MODEL FOR EVAPOTRANSPIRATION OF WHEAT: EFFECT OF EVAPORATIVE CONDI-
TIONS,
Strateener, G., Yaron, D., Bresler, E., and Shimshi, D.
Hebrew University, Jerusalem (Israel).
Journal of the Irrigation and Drainage Division, Proceeding of American Society
of Civil Engineers, Vol 101, No IR1, Proceedings Paper 11169, p 13-19, March 1975.
4 tab, 3 ref, 2 append.
Descriptors: *Evapotranspiration, *Simulation analysis, *Agriculture, *Irriga-
tion, *Wheat, Consumptive use. Soil moisture. Evaporation, Computers, Computer
programs, Field capacity, Regression analysis, Plant growth, Root systems,
Soil profiles, Model studies, Evaporation pans, Canopy.
A simulation model for tracing soil moisture fluctuations under irrigated wheat
in a semi-arid climate was presented. The model was based on a function relating
evapotranspiration to soil moisture and evaporative conditions as measured
by means of a class A pan. The recharge of soil moisture by rain or irrigation
was predicted by this model on the basis of a simplified infiltration scheme
with the conventional concept of 'field capacity1 as the upper limit of soil
moisture in the soil profile. By means of an iterative procedure, the 'best
fitting' parameters were computed for each soil layer and each month from data
on a wheat irrigation experiment in the arid Negev region in the year 1967-1968.
The average relative deviation of the predicted soil moisture from the observed
soil moisture was 9.3% for the five soil layers and 6.2% for the upper three
soil layers. The reliability of the model was presented by these and other
data and its performance was examined.
75:02D-002
SIMULATION MODEL FOR EVAPOTRANSPIRATION OF WHEAT: EMPIRICAL APPROACH,
Shimshi, D., Yaron, D., Bresler, E., Weisbrod, M., and Strateener, G.
Agricultural Research Organization, Bet Dagan (Israel). Institute of Soils and
Water.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol 101, No IR1, Proceedings Paper 11170, p 1-12, March 1975. 2 fig,
4 tab, 16 ref, 2 append.
Descriptors: *Evapotranspiration, *Wheat, *Simulation analysis, Agriculture,
*Soil water, Root zone, Irrigation, Rain water. Arid lands, Infiltration, Soil
surfaces, Wetting, Field capacity. Water loss, Root systems. Soil profiles,
Canopy, Evaporation, *Model studies.
A simulation model was described for predicting the changes in the soil-water
content of the root zone of wheat growing under various irrigation regimes in a
semi-arid region. The model was based on the following assumptions: (1) irri-
gation water and rainwater infiltrates from the soil surface, wetting each suc-
cessive soil layer as the overlying one is wetted in excess of the field capacity
(as conventionally defined); and (2) the rate of water loss from the soil changes
with time and with depth of soil. Parameters were determined empirically from
soil moisture data collected from a series of wheat irrigation experiments
carried out over a 4-year period in northern Negev, Israel. The average relative
deviation between computed and observed values of soil moisture ranged from 8.8
to 13.5%. The changes in parameters reflected the development of the root system
in the soil profile and the changes in time of canopy cover and evaporation con-
ditions.
75:020-003
PERSISTENCE OF SELECTED ANTITRANSPIRANTS,
Kreith, F., Taori, A., and Anderson, J.E.
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Colorado University, Boulder. Department of Chemical Engineering.
Water Resources Research, Vol 11, No 2, p 281-286, April 1975. 5 fig, 15 ref.
Descriptors: *Antitranspirants, *Persistence, *Tobacco, Water vapor, Phenols,
Sprays, Leaves, Water loss, Transpiration, Transpiration control, Analytical
techniques, Ecology, Laboratory tests.
The short- and long-term effectiveness of two film-forming and two physiologically
active antitranspirants was evaluated on tobacco leaves under controlled experi-
mental conditions. The physiologically active antitranspirants (phenylmercuric
acetate and monoglycerol ester of n-decenyl succinic acid) initially reduced
water loss to less than 40% of controls, but their effectiveness diminished
sharply within 203 days. Treatment with the film-forming antitranspirants
(Wilt Pruf and Mobileaf) resulted in initial transpiration reductions to 50-65%
of controls, but the duration of effectiveness was longer with these than with
the metabolic agents. The results were compared with those of previous studies,
and implications for large-scale antitranspirant applications were discussed.
Since the cost of water varied considerably in different parts of the world, the
economic viability of using antitranspirants could not be ascertained by a
technical study alone. Under conditions for which water is expensive or not a-
vailable, the use of antitranspirants may be economical provided no adverse eco-
logical effects occur.
75:020-004
RESPONSE OF AN UNSATURATED SOIL TO FOREST TRANSPIRATION,
Parlange, J-Y, and Aylor, D.E.
Connecticut Agricultural Experiment Station, New Haven.
Water Resources Research, Vol 11, No 2, p 319-323, April 1975. 3 fig, 12 ref,
1 append.
Descriptors: *Transpiration, *Discharge(Water), *Forest watersheds, Evaporation,
Diurnal, Saturated soils, Soil water, Soil Moisture, Hydrologic aspects, Water
consumption, Seepage, Deep percolation, Cycles, Gravimetric analysis, Connec-
ticut, Forests, Moisture content, Movement, *Connecticut.
Diurnal cycles in water outflow from a small watershed due to forest transpira-
tion were observed 4 times during August 1973. Each time the daytime outflow
was reduced significantly below that during the following night. The recovery
of the outflow to the steady night level took place for several hours after sun-
set, and this time of recovery was shown to be controlled by the unsaturated
soil water movement in the root zone. The observations of transpiration were
made on a small area of a 5-acre forested watershed in North Madison, Connecti-
cut, surrounding a lake. Water seeped from the lake into the observation plot
and emerged on the other side where it passed through a weir and was monitored
continuously. The difference between the amount of water seeping into the test
plot from the lake and the measured outflow determined the evapotranspiration
from the plot.
75:020-005
AVERAGING ERRORS IN MONTHLY EVAPORATION ESTIMATES,
Hage, K.D.
Alberta University, Edmonton. Department of Geography.
Water Resources Research, Vol 11, No 2, p 359-361, April 1975. 2 tab, 6 ref.
Descriptors: *Evaporation, *Climatology, *Estimating, Temperature, Humidity,
Environment, Wind velocity, Vapor pressure. Model studies. Hydrology, Heat flow,
Latent heat. Weather, Data processing. Water temperature, Diffusion.
The problem of computing evaporation from monthly mean values of temperature,
relative humidity, and wind was considered with specific reference to a Dalton-
type evaporation formula. Leading contributions due to nonlinearities, covar-
iances, and their interactions were identified separately by expanding satura-
tion vapor pressure as a Taylor series in temperature with the use of the
Clausius-Clapeyron equation. A truncated form of the expansion was tested by
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using observations from a land station. A crude model of diurnal variations
in air temperature, relative humidity, and wind speed was used to predict non-
linearity and covariance evaporation errors from monthly mean observations at
2 times per day. The model appeared to be accurate to within plus or minus
5% in warm seasons months but failed in winter when diurnal variability was
negligible in comparison with air mass changes in weather elements at mid-
latitude continental locations. Covariance and nonlinearity errors did not
compensate each other in winter and averaging errors could reach 20-25%.
75:020-006
DIURNAL AND SEASONAL SOIL WATER UPTAKE AND FLUX WITHIN A BERMUDAGRASS ROOT ZONE,
Rice, R.C.
Agricultural Research Service, Phoenix, Arizona Water Conservation Lab.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 394-398, May-
June 1975. 9 fig, 2 tab, 9 ref.
Descriptors: *Evaoptranspiration, *Soil water, *Unsaturated flow, *Hydraulic
conductivity, Bermudagrass, Lawns, Water utilization, Root zone, Consumptive
use, Irrigation, On-site investigations, Soil water movement, Soil moisture,
Subsurface flow, Vegetation, Diurnal, Seasonal, Pressure head, Tensiometers.
Diurnal water movement within a bermudagrass root zone and the uptake of water
by the roots was studied in a field plot. A fast response tensiometer-pressure-
transducer system was used to measure the hydraulic head. The relations of pres-
sure head to water content and to hydraulic conductivity were determined in situ.
Diurnal water content and soil water flux profiles were derived by using the es-
tablished hydraulic properties. The fast response tensiometer system enabled
calculation of flux and water content changes over 2-hour intervals. Diurnal
water extraction rates calculated for different depths and times during the grow-
ing season yielded evapotranspiration rates that agreed well with rates measured
on similar days in previous years using a lysimeter. The water uptake pattern
changes rapidly near the surface during the first few days after irrigation.
Rewetting within the soil profile occurred in late afternoon at depths where up-
ward gradients were present. The seasonal consumptive-use curve can be estimated
from several daily evapotranspiration rates calculated during the growing season.
75:020-007
CHANGES IN CLIMATE AND ESTIMATED EVAPORATION ACROSS A LARGE IRRIGATED AREA IN
IDAHO,
Burman, R.D., Wright, J.L., Jensen, M.E.
Wyoming University, Laramie, Agricultural Engineering Department.
Transactions of the American Society of Agricultural Engineers, Vol. 18 No. 6,
p 1089-1093, November-December. 7 fig, 3 tab. 16 ref.
Descriptors: *Irrigation, *Irrigation effects, *Evaporation, *Climate, Idaho,
Weather, Weather modification, Evapotranspiration.
Ground level climatic measurements were taken along a 50 km transect going from
dry sagebrush land into the center of a large irrigated area in southern Idaho.
Measurements in May, when the desert area was dry, indicated that climatic changes
across the transect were minimal. In August when the desert was obviously very
dry, air temperatures decreased, vapor pressure increased, and windspeed was
reduced about 40 percent within the irrigated area. The results demonstrate that
any weather service agency or group must consider the distance from dry surround-
ings when selecting sites that are to be representative of climatic conditions
over irrigated fields.
75:020-008
COMPARISON OF WARM WATER EVAPORATION EQUATIONS,
Weisman, R.N.
Canterbury, University, Christchurch, New Zealand. Department of Civil Engineer-
ing.
Journal of the Hydraulics Division, Vol. 101, No. HY10, p 1303-1313, October 1975.
2 fig, 2 tab, 12 ref, 2 append.
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Two methods of calculating evaporation from water bodies have been reviewed. In
one method, a purely free convective term is added to a forced convective term
under near neutral atmospheric conditions to obtain a total evaporation equation.
In the second method, the results of a numerical solution to turbulent diffusion
equations for conditions of simultaneous free and forced convection based on
Monin-Obukhov similarity are used to calculate evaporation. The comparison of
the results is approximate because the R-H type model contains a wind profile
for unstable conditions is used. A wide range of wind speed, air and surface
temperatures, and vapor pressures were assumed as imput to the two models.
75:020-009
EVAPOTRANSPIRATION OF DRYLAND BARLEY WITH DIFFERENT PLANT SPACING PATTERNS,
Luebs, R.E., Laag, A.E., Nash, P.A.
California University, Riverside.
Agronomy Journal, Vol. 67, No. 3, p 339-342, May-June, 1975. 1 fig, 3 tab, 6 ref.
Descriptors: *Evapotranspiration, *Crop production, *Crop response, *Planting
management, *Barley, Drought resistance, Growth stages, Plant growth, Water
requirements, Water utilization, Lysimeters, Soil moisture, Transpiration, Plant
physiology. Soil-water-plant relationships, Moisture stress, Canopy.
Results are reported of an experiment which was conducted during the 1969-70
growing season near Riverside, California, to study the effect of plant spacing
patterns of dryland barley (Hordeum vulgare L.) on leaf area index, crop canopy,
evapotranspiration, and yield. The minimum unit area of equal plant population
density for all spacing patterns was 240 sq cm. Crop canopy and leaf area index
were lowest for the grid spacing pattern (.8.3-cm row spacing with seeds spaced
7.4 cm in the row) largely because of less tillering. The paired-row pattern
(8.1 cm spacing between rows in a pair and 24.3 cm between pairs with seeds spaced
3.7 cm in the row) had highest leaf area index but intermediate crop canopy
during the vegetative phase with adequate water. Slightly greater evapotranspira-
tion values were found during the first two-thirds of the growing season for the
standard row pattern (16.3-cm row spacing with plants spaced 3.7 cm in the row)
which resulted in greater water stress and lower evapotranspiration values later
in the season, but grain yield was not affected.
75:020-010
A THEORY FOR LOCAL EVAPORATION (OR HEAT TRANSFER) FROM ROUGH AND SMOOTH SURFACES
AT GROUND LEVEL,
Brutsaert, W.
Cornell University, Ithaca, N.Y. School of Civil and Environmental Engineering.
Water Resources Research, Vol. 11, No. 4, p 543-550, August 1975. 7 fig, 40 ref.
Descriptors: *Evaporation, *Heat transfer, Atmosphere, Humidity, Shear, Turbulent
flow, Eddies, *Model studies, Surface tension, Theoretical analysis, Interfaces,
*Diffusion, Diffusivity, Drag, Shear stress.
A model proposed in 1965 for evaporation as a molecular diffusion process into
a turbulent atmosphere was extended by joining it with the similarity models for
turbulent transfer in the surface sublayer. The assumed mechanisms were suggested
by available flow visualization studies near smooth and rough walls; the theoreti-
cal result was in good agreement with available experimental evidence. The im-
portant dimensionless parameters governing the phenomenon near the surface were
the Dalton (or Stanton) number (i.e., mass transfer coefficient), the drag coeffi-
cient, the roughness Reynolds number (except for smooth surfaces), and the Schmidt
(or Prandtl) number. The proposed formulation allowed the evaluation of the
effects of some parameters, such as surface roughness or molecular diffusivity,
that were not well understood before this. An important practical result was
that, in contrast to the drag coefficient, the Dalton number is relatively insen-
sitive to changes in roughness length.
75:02D-011
SIMULATION OF EVAPOTRANSPIRATION AND DRAINAGE FROM MATURE AND CLEAR-CUT DECIDUOUS
FORESTS AND YOUNG PINE PLANTATION,
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Swift, L.W., Swank, W.T., Mankin, J.B., Luxmoore, R.J., Goldstein, R.A.
Forest Service (USDA), Franklin, N.C. Coweeta Hydrologic Lab.
Water Resources Research, Vol. 11, No. 5, p 667-673, October 1975, 3 fig, 7 tab,
23 ref.
Descriptors: *Simulation analysis, *Evapotranspiration, *Drainage, *Deciduous
forest, *Pinte trees, *Appalachian Mountain Region, Soils, Atmosphere, Oak trees,
Hickory trees, Hardwood, Watersheds(Basins), Vegetation, Meteorological data,
Seasonal, Soil moisture, *Model studies.
Prosper, a phenomenological model of water exchange between soil, plant, and
atmosphere, was used to simulate evapotranspiration and annual drainage for 2
years from a mature oak-hickory forest in the southern Appalachians. The simula-
tion was tested by comparing drainage to measured streamflow. In a year of un-
usually high precipitation the simulated annual drainage was within 1.5% of
measured streamflow. Simulations were also performed by using the same 2 years
of meterologic data, but vegetation parameters were changed to represent a young
white pine plantation and a regrowing hardwood forest one year after clear-cut-
ting. The model estimated that drainage for an average rainfall year was reduced
20 cm by a 16-year-old white pine plantation and increased 36 cm by clear-
cutting. These results were comparable to changes of -20 and +38 cm observed
in watershed experiments at Coweeta Hydrologic Laboratory. Simulated evapotrans-
piration during the summer was nearly identical for hardwood and pine forests,
while winter and early spring water loss was greater for pine. Simulation sug-
gested that the greater evapotranspiration by pine was due to increased inter-
ception in all seasons and increased transpiration in the dormant season. For
the clearcut area, simulated evapotranspiration was considerably less than it
was for the pine or hardwood forest and thus caused simulated soil moisture con-
tents to be greater during the summer season.
75:02D-012
INCLUSION OF PLANT MOISTURE STATUS IN COMBINATION-METHOD ESTIMATES OF PASTURE
EVAPORATION,
Shepherd, W.
Commonwealth Scientific and Industrial Research Organization, Aspendale (Australia)
Div- of Atmospheric Physics.
Journal of Hydrology, Vol. 26, No. 3/4, p 199-207, August 1975. 3 fig, 1 tab,
10 ref.
Descriptors: *Evaporation, *Pastures, *Plant physiology, *Moisture, Energy budget,
Moisture stress, Soil moisture, Grasslands.
A combination-type formula for estimation of evaporation under conditions of re-
stricted water supply was considered in earlier work. The formula involved an
'internal conductance1 factor. Relationships of the conductance to indexes of mois-
ture status of pasture species, determined over a range of soil-moisture conditions,
was described here. Once established, these relationships were employed to esti-
mate conductances, which were then used to determine evaporation over later periods
of pasture growth. The investigations demonstrated that inclusion of plant-moisture
stress data into a combination formula could afford estimates of pasture evapora-
tion which were significantly better than those obtained by more empirical means.
75:020-013
ESTIMATING ENERGY BUDGET COMPONENTS TO DETERMINE LAKE HURON EVAPORATION,
Bolsenga, S.J.
National Oceanic and Atmospheric Administration, Ann Arbor, Michigan, Great Lakes
Environmental REsearch Lab.
Water Resources REsearch, Vol. 11, No. 5, p 661-666, October 1975. 2 fig, 3 tab,
22 ref.
Descriptors: *Evaporation, *Lake Huron, Energy budget, Mass transfer, Great Lakes,
Energy, Heat flow, Advection, Lakes, Estimating.
Evaporation was estimated for Lake Huron by the energy budget method and compared
-------
to available mass transfer estimates. Data from representative shoreline station
measurements and vessel cruise measurements were collected. Agreement between
evaporation by the energy budget and by mass transfer was reasonable from February
through July, with the exception of May when measurement of the heat content was
a problem. For the remainder of the year the disparity was marked. The principal
difficulty encountered was the lack of meteorological measurements on the lake
and adequate techniques to extrapolate the quantities from shoreline data.
Quantitative monthly values for each component in the budget equation were the
first published for Lake Huron and one of the few sets available for the Great
Lakes.
10
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Section V
WATER CYCLE
STREAMFLOW AND RUNOFF (GROUP 02E)
75:02E-001
OPTIMIZING PARAMETERS FOR A WATERSHED MODEL,
Shanholtz/ V.O., Carr, J.C.
Virginia Polytechnic Institute and State University, Blacksburg. Department of
Agricultural Engineering.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 2,
p 307-311, March-April 1975. 4 fig, 3 tab, 9 ref.
Descriptors: *Model studies, *Simulation analysis, *Computer models, Optimization,
Hydrology, Analytical techniques, Hydrologic aspects, Runoff, Mathematical models.
Mathematics, Watersheds (Basins), Parametric hydrology.
Use of the Kentucky Watershed Model and experimentation with various land phase
parameters were discussed. Examples were present demonstrating the year-to-year
parameter variation and the effect of including additional records. Potential
errors due to unrepresentative, short periods of record were also discussed.
When longer historical records were available, new criteria for selecting repre-
sentative input data were presented.
75:02E-002
WATERSHED SOIL DETACHMENT AND TRANSPORTATION FACTORS,
Onstad, C.A., Moldenhauer, W.C.
United States Department of Agriculture, Morris, Minnesota 56267
Journal of Environmental Quality, Vol. 4, No. 1, p 29-33, January-March 1975.
2 fig, 21 ref.
Descriptors: *Simulation analysis, *Model studies, *Sediment transport,
Erosion, Erosion rates.
Quantification of sediment yields from agricultural watersheds requires that
consideration be given to spatial and temporal variations in the parameters
known to influence soil erosion by water. This includes accounting for vari-
ations in rainfall and runoff, the energy sources, on a storm-by-storm basis.
Also to be considered are the distribution of watershed topography, soils,
tillage practices, and vegetation which influence the degree of erosion or
deposition. These factors are discussed with regard to simulation of the
erosion-deposition continum on agricultural watersheds.
75:02E-003
ON THE IMPOSSIBILITY OF A PARTIAL MASS VIOLATION IN SURFACE RUNOFF SYSTEMS,
Diskin, M.H., Boneh, A., and Golan, A.
Technion-Israel Institute of Technology, Haifa. Faculty of Civil Engineering.
Water Resources Research, Vol. 11, No. 2, p 236-244, April 1975. 9 fig, 9 ref.
Descriptors: *Surface runoff, *Systems analysis, *Rainfall-runoff relationships,
Hydrographs, Hydrologic cycle, Hydrology, Flood flow, Hydrologic systems. In-
put-output analysis, Optimization, Theoretical analysis, Model studies.
The class of nonnegative, initially relaxed, and nonanticipating systems has
many applications in engineering. A proof was given to a theorem stating that
in this class of systems, if the input total mass is equal to the output total
mass, then for any nonnegative input-output pair, the system fulfills also a
partial mass condition. By applying this theorem to systems expressed by the
Volterra series it was concluded that the input functions must be bounded.
Two such bounds on the input functions were considered: (1) bounds resulting
from the requirement of a nonnegative output and (2) bounds resulting from the
11
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mass-conserving property of the system. The theorem mentioned above implies
that the set of input functions causing nonnegative output functions is a sub-
set of the set of input functions that do not violate the mass-conserving
property of the system. It is therefore clear that the bounds of type 1 are
the dominant among the two bounds for any nonnegative input function. In
a system expressed by an Nth order Volterra series the bounds on the input can
be evaluated by solving a polynomial inequality of order N - 1. An example
was given for a system expressed by a third-order Volterra series in which the
bounds on the input form two regions. Explicit equations for the bounds of
type 1 and 2 were derived for a second-order system.
75:02E-004
SAMPLING PROCEDURES FOR NITROGEN AND PHOSPHORUS IN RUNOFF,
Burwell, R.E., Schuman, G.E., Piest, R.F., Larson, W.E., Alberts, E.E.
United States Department of Agriculture, Columbia, MO
Transactions of the American Society of Agricultural Engineers, Vol. 18 No. 5,
p 912-917, September-October 1975. 2 fig, 5 tab, 10 ref.
The nitrogen and phosphorus content of surface runoff from two watersheds in
south-western Iowa was analyzed for a 5-year period (1969-1973) . Sampling pro-
cedures were evaluated for quantifying discharges of water-soluble N03-N, NH4-N,
and inorganic P and sediment-associated Kjeldahl N and NaHC03-extractable P.
The arithmetic mean nutrient concentration of samples collected during major run-
off multiplied by the quantity of water or sediment discharged, compared favorably
with a standard integration procedure for determining N and P discharges associ-
ated with surface runoff. Also, the arithmetic mean nutrient concentration of
three samples collected during major runoff was adequate for determining storm
discharges of water-soluble N03-N and NH4-N and of Kjeldahl N associated with
sediment. Nitrate-nitrogen concentrations showed a progressive decrease from
storm to storm, indicating that each storm made for this decrease to determine
the storm quantity discharges of N03-N during the cropping season. This storm-
to-storm effect was not as evident for NH4-N inorganic P, total Kjeldahl N, and
NaHC03-extractable P, indicating that sampling of every event would not be re-
quired to determine cropping season quantity discharges of these nutrient consti-
tuents.
12
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Section VI
WATER CYCLE
GROUNDWATER (GROUP 02F)
75:02F-001
A SURROGATE-PARAMETER APPROACH TO MODELING GROUNDWATER BASINS,
Labadie, J.W.
Colorado State University, Fort Collins, Department of Civil Engineering
Water Resources Bulletin, Vol. 11, No. 1, p 97-114, February 1975. 5 fig, 13 ref.
Descriptor: *Parametric hydrology, *Mathematical models, *Groundwater basins,
Hydrogeology, Least squares method, Model studies.
A surrogate-parameter approach to modeling groundwater basins was presented,
which has the following advantages over current simulation-type methods: (1)
conducivness to modeling nonhomogeneous and nonisotropic basins; (2) there is
no need to guess boundary conditions if accurate information is not available;
(3) the model is amenable to systematic calibration or identification through
the use of optimization techniques; and (4) compatibility with systematic
algorithms for analyzing a wide range of management strategies. Since the
parameter identification problem is large-scale and nonconvex, it was decomposed
through application of generalized duality theory into several sub-problems
of smaller size which were solved independently a number of times in order to
achieve an overall solution. Results were presented for a hypothetical system
of four interacting wells.
75:02F-002
TRANSFER OF BORON AND TRITIATED WATER THROUGH SANDSTONE,
Wierenga, P.J., van Genuchten, M.T., Boyle, F.W.
New Mexico State University, Las Cruces, Department of Agronomy
Journal of Environmental Quality, Vol. 4, No. 1, p 83-87, January-March 1975.
4 fig, 1 tab, 25 ref.
Descriptors: *Sandstones, *Boron, *Dispersion, *Groundwater, *Water quality,
Groundwater recharge, Groundwater basins.
The movement of tritiated water and boron were determined during unsaturated
flow through undisturbed sandstone cores.. From the displacement and slope
of the breakthrough curves relative to 1 pore volume of effluent, adsorption
coefficients and dispersion coefficients were calculated of 0.135 and 1.06
cm(2)/day for boron, and 0.04 and 3.45 cm(2)/day for tritiated water, respec-
tively. The data were used to predict the downward movement of boron through
a sandstone formation in the Four Corners area of New Mexico. With 20 cm annual
rainfall and 10% of the precipitation contributing to recharge, it was cal-
culated to take 1.628 years for the boron concentration at the soil
surface.
75:02F-003
ANALYSIS OF PUMPING TEST DATA FROM ANISOTROPIC UNCONFINED AQUIFERS CONSIDERING
DELAYED GRAVITY RESPONSE,
Neuman, S.P.
Agricultural Research Organization, Bet Dagan (Israel). Institute of Soils and
Water.
Water Resources Research, Vol. 11, No. 2, p 329-342, April 1975. 9 fig, 2 tab,
22'ref.
Descriptors: *Groundwater, *Aquifers, *Aquifer characteristics, *Aquifer testing,
*Mathematical studies, Pump testing, Testing, Drawdown, Specific yield, Water
wells, Unsteady flow, Equations, Anisotropy, Analysis, Observation wells.
13
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A new analytical model was proposed for the delayed response process character-
izing flow to a well in an unconfined aquifer. The new approach was based
only on well-defined physical parameters of the aquifer system. As such, it
can be used to develop methods for determining the hydraulic properties of
anisotropic unconfined aquifers from field drawdown data. Two methods of anal-
ysis were described, one based on the matching of field data with theoretical
type curves and the other based on the semi-logarithmic relationship between
drawdown and time. These methods were illustrated by applying them to field
pumping tests. Similar procedures can be used to analyze data from partially
penetrating wells, but this requires that a special set of theoretical curves
be developed for each field situation. Such theoretical curves can easily be
developed with the aid of a computer program. An explicit mathematical rela-
tionship was derived between Boulton's delay index and the physical character-
istics of the aquifer. It was shown that contrary to the assumption of Boulton
the delay index is not a characteristic constant of the aquifer but decreases
linearly with the logarithm of the radial distance from the pumping well. This
discovery makes it possible to reinterpret the results of pumping tests that
were previously obtained with the aid of Boulton's theory without necessarily
reexamining the original drawdown data. Results from pumping tests were used
to illustrate this last point.
75:02F-004
A STOCHASTIC MODEL OF DISPERSION IN A POROUS MEDIUM,
Todorovic, P.
Ecole Polytechnique, Montreal (Quebec).
Water Resources Research, Vol. 11, No. 2, p 348-354, April 1975. 4 fig, 10 ref.
Descriptors: *Stochastic processes, *Dispersion, *Porous media, *Groundwater,
Equations, Mathematical studies, Diffusion, Groundwater movement, Dif f-usivity,
Statistical methods, Saturated flow, Mass transfer, Model studies, Hydraulics,
Probability.
A set of tagged particles released in a flow through a porous medium is subject
to random dispersion. For a statistically homogeneous and isotropic porous
medium a stochastic model of longitudinal dispersion was determined, provided
the fluid flow was steady and no mass transfer occurs between the solid phase
and the fluid. A stochastic model was presented to describe longitudinal dis-
persion of a set of tagged particles released continuously (but not necessarily
at uniform rate) in a flow through a porous structure. The model depends on
two constant parameters which in turn depend on the properties of the porous
medium and hydraulic conditions. It was emphasized that the model presented
was kinematic in the sense that it treated only the statistical properties of
the law of motion of a tagged particle in a flow through a porous medium and did
not go into particulars of dynamic conditions. Consequently, it did not expli-
citly contain parameters of the hydraulic forces leading to this motion.
75:02F-005
EFFECT OF SOLUTE DISPERSION ON THERMAL CONVECTION IN A POROUS MEDIUM LAYER, 2,
Rubin, H.
Technion-Israel Institute of Technology, Haifa. Faculty of Civil Engineering.
Water resources Research, Vol. 11, No. 1, p 154-158, February 1975. 4 fig, 8 ref.
Descriptors: *Solutes, *Dispersion, *Convection, *Temperature, *Porous media,
Heat transfer, Mathematical models. Boundaries(Surfaces), Equations, Currents
(Water), Groundwater movement, Aquifers, Stratification, Salinity.
In some situations associated with geothermal activity, groundwater motions are
affected by convection currents due to large temperature gradients. In such
cases, usually saline hot water is located in the deep layers of the aquifer from
which salt and heat are transferred to the upper layers. In part 1 - of this
study the parameters of the two-dimensional flow field stability were deter-
mined. In part 2, further analysis of the phenomenon in three dimensions was
14
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presented. It was found that the convection cells have the shape of rolls
whose axes are perpendicular to the steady state flow velocity. However, there
is also a possibility of overstability of the flow field caused by rolls whose
axes are parallel to the steady state velocity. The parameters of these two
kinds of instability were determined.
75:02F-006
SUBSURFACE FLOW FROM SNOWMELT TRACED BY TRITIUM,
Martinec, J.
Swiss Federal Institute for Snow and Avalanche Research, Davos-Weissfluhjoch.
Water Resources Research, Vol. 11, No. 3, p 496-498, June 1975. 3 fig, 8 ref.
Descriptors: *Subsurface runoff, *Melt water, *Tritium, *Tracers, Groundwater
movement, Snow, Runoff, On-site investigations, Infiltration, Discharge(Water),
Hydrograph analysis, Lysimeters, Dispersion, Velocity, Radioisotopes, Recession
curves.
An explanation was offered of the apparent discrepency between the small veloci-
ties of subsurface flow and the watershed response. Environmental tritium in the
hydrological cycle provided evidence for a new insight into the runoff mechanism.
By this concept the quick reaction of outflow to a massive groundwater recharge
was brought to agreement with the long residence time of the infiltrated water.
75:02F-007
IDENTIFICATION OF PARAMETERS IN A LINEAR EQUATION OF GROUNDWATER FLOW,
Nutbrown, D.A.
Department of the Environment, Reading (England). Central Water Planning Unit.
Water Resources Research, Vol. 11, No. 4, p 581-588, August, 1975. 12 fig,
5 ref, 1 append.
Descriptors: *Groundwater movement, *Hydrologic data, *Systems analysis,
*Computer models, *Aquifer systems, Base flow, Model studies, Mathematical
studies, Linear programming, Mathematical models, Finite element analysis,
Analytical techniques, Transimissivity, Aquifer characteristics, Aquifers, Inflow,
Groundwater recharge, Withdrawal.
An inductive method is presented for evaluation parameters in a two-dimensional
linear equation describing groundwater flow. The approach employs finite differ-
ence approximations, which can be simply programmed for calculation by computer.
Before illustrating the method, which is applicable to both stationary and time-
dependent problems, the various types of data required for evaluation in general
are systematically enumerated. An assumption is introduced limiting the local
variability of T, the tranmissivity, and its relation to apparently similar
assumptions used elsewhere is discussed. The particular aquifer chosen for
illustration is the chalk of the South Downs between the rivers Adur and Ouse.
The parameters are calculated on the basis of cyclic data in which annual ab-
straction is about 30% of the total infiltration for the year. The method gives
a match to the minimum and maximum water levels during the year to within 7%.
75:02F-008
CARBON 14 DATING OF GROUNDWATER FROM CLOSED AND OPEN SYSTEMS,
Wigley, T.M.L.
Waterloo University (Ontario). Department of mechanical Engineering.
Water Resources Research, Vol. 11, No. 2, p 324-328, April 1975. 2 fig, 1 tab,
14 ref.
Descriptors: *Isotope studies, *Carbon radioisotopes, *Radioactive dating,
Groundwater recharge, Stable isotopes, Isotope fractionation, Geochemistry,
Temperature, Aquifer systems, Hydrogeology, *Florida, Groundwater, Aquifers.
15
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Groundwaters may be dated by using carbon 14, provided that the raw data are
properly adjusted. However, adjustment factors determined from geochemical or
isotopic measurements and based on simple models of carbonate dissolution do not
always agree with adjustment factors obtained by independent means. Established
adjustment methods were reinterpreted in terms of closed and open system models
of carbonate dissolution, and it was suggested thatthese models provide a soun-
der framework for determining adjustment factors. Hypothetical and real ex-
amples were considered, and it was shown that some otherwise anamalous results
may be explained in terms of the closed and open system models.
75:02F-009
GROUND-WATER RECHARGE SIMULATION,
Amar, A.C.
New South Wales University, Duntroon, Australia, Faculty of military Studies.
Journal of the Hydraulics Division, Vol. 101, No. HY9 p 1235-1247. September
1975. 6 fig, 17 ref, 2 append.
Descriptors: *Ground water recharge, *Simulation analysis, Aquifers, Groundwater
basins, Groundwater movement.
The purpose of this paper is to investigate the two-dimensional hydrodynamic be-
havior of recharge of an unconfined aquifer based on the potential theory formu-
lation. As is well known, the basic mathematical equation, according to poten-
tial theory for flow through porous media, is Lablace's equation in combination
with the time-dependent nonlinear boundary conditions on the curvilinear moving
free surface for which there is no known general analytical solution at present
(1975). The solution of this equation by a computational technique based on the
Accelerated Liebman Method is the primary objective of this paper. It will be
assumed that the flow is unsteady and the aquifer medium is saturated, homogene-
ous, and isotropic.
75:02F-010
A DIRECT METHOD FOR THE IDENTIFICATION OF THE PARAMETERS OF DYNAMIC NONHOMO-
GENEOUS AQUIFERS,
Sagar, B., Yakowitz, S., Duckstein, L.
Punjab Agricultural University, Ludhiana, Punjab, India, Department of Civil
Engineering.
Water Resources Research, Vol. 11 No. 4, p 563-570, August 1975. 3 fig, 1 tab,
31 ref.
Descriptors: *Aquifer characteristics, *Aquifers, Aquifer testing, *Transmissi-
vity, Groundwater, Groundwater movement, Model studies.
The investigation reported in this paper deals with a new direct method for iden-
tifying the parameters of a regional aquifer mode. The estimation of flow pro-
perties (such as the coefficient of transmissivity, heat conduction, or disper-
sion) of the aquifer is one of the critical problems for the management of ground-
water resources or conjunction management of groundwater and surface water. The
example of a simulated isotropic nonhomogeneous aquifer is used to illustrate
how the algebraic method recovers the transmissivity coefficient.
75:02F-011
BI-LEVEL SUBSURFACE DRAINAGE THEORY,
DeBoer, D.S., Chu, S.T.
South Dakota State University, Brookings, Agricultural Engineering Department.
Transactions of the American Society of Agricultural Engineers, Vol. 18 No. 4,
p 665-667, July-August 1975. 4 fig, 6 ref.
16
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Descriptors: *Drainage, *Drainage design, *Drains, Soil water movement, Irri-
gation effects, Drainage practices.
Drain line depths and spacings are generally greater for irrigated lands in the
arid and semi-arid parts of the United States than for lands in the humid
region. The average Oahe Unit drain line depth and spacing are estimated to be
2.7 m(9 ft) and 240m (790 ft), respectively. Cuts of 2.7 m require installa-
tion procedures which include the construction of a trench. Recently developed
equipment that can successfully "plow-in" flexible drain tubing to a depth
of 1.8 m (6 ft) has the potential to reduce subsurface drainage costs of the
Oahe Unit even though the average drain depths are greater than the maximum
installation depths of the present equipment. This can be accomplished by using
the normal deep drain lines on an alternating basis with shallower drain lines.
Since the drain lines are at two different elevations or levels in the drainage
system, the terminology "bi-level drainage" seems appropriate. The objective
of this paper is to develop analytical procedures to determine the maximum
height of bi-level drainage water tables for steady state and falling water table
cases.
75:02F-012
WATER FLOW THROUGH A MULTILAYER STRATIFIED HILLSIDE,
Selim, H.M.
Florida University, Gainesville. Department of Soil Science.
Water Resources Research, Vol. 11, No. 6, p 949-957, December 1975. 13 fig,
3 tab, 11 ref.
Descriptors: *Groundwater movement, *Stratification, *Mathematical models,
Equations, Aquifers, Beds, Hydraulic Conductivity, Saturated flow, Ground-
water potential, Boundary layers, Depth, Ponds, Flow nets, Seepage, Flow rates,
Potentiometric level, Subsurface runoff, Slopes.
The objective of this study was to present a mathematical analysis for steady
state saturated flow through multilayer stratified hillsides of semi-in-finite
depth. Two soil surface shapes were considered: a constant soil surface slope
and a surface of arbitrary shape. Potential and stream functions were obtained
for one-, two-, and three-layered hillsides. The method of solution was based
on the Gram-Schmidt orthonormalization method. For two-layered hillsides the
hydraulic conductivities considered were K sub 1: K sub 2 = 1:10 and 10:1.
For three-layered hillsides the hydraulic conductivities were K sub 1 : K sub
2 : K sub 3 = 1:10:1 and 10:1:10- Flow nets, seepage velocities, and flow rates
were presented. These results were useful particularly with regard to subsurface
flow, runoff, erosion, and solute movement through sloping soils.
75:02F-013
A HELE-SHAW MODEL STUDY OF STEADY STATE FLOW IN AN UNCONFINED AQUIFER RESTING
ON A SLOPING BED,
Jaiswal, C.S., Chauhan, H.S.
Govind Ballabh Pant University of Agriculture and Technology, Pantnagar
(India). Department of Agricultural Engineering.
Water Resources Research, Vol. 11, No. 4, p 595-600, August 1975. 4 fig,
1 tab, 7- ref.
Descriptors: *Model studies, *Groundwater movement, *Slopes, *Seepage, Aquifers,
Aquicludes, Water table aquifers, Equations, Height, Groundwater, Viscosity,
Theoretical analysis, Steady flow.
17
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Experiments were conducted on a vertical Hele-Shaw model to study the effect
of slope of an impermeable layer on flow profiles and flow rates in an uncon-
fined aquifer. Experimental results were compared with the solutions of Pavlov-
sky (1930) and Childs (1971) for nonuniform seepage on a small sloping impermea-
ble bed. These studies showed that the solution of Pavlovsky may be used for the
prediction of the flow profile downslope up to 30% slope and upslope up to 15%
slope. Pavlovsky's equations also predicted flow rates and normal depths
satisfactorily up to 30% slope. Child's equations also predicted similar results.
None of these equations predicted the flow rate on negative slope satisfactorily.
75:02F-014
AQUIFER PARAMETER IDENTIFICATION,
Yen, W.W-G.
California University, Los Angeles. Department of Engineering Systems.
Journal of the Hydraulics Division, Proceedings of American Society of Civil
Engineers, Vol. 101, No. HY9, Paper 11582, p 1197-1209, September 1975. 2 fig,
2 tab, 27 ref, 2 append.
Descriptors: *Groundwater, *Aquifer characteristics, *Numerical analysis, *Un-
steady flow, Aquifers, Optimization, Mathematical studies, Hydraulics, Equations,
Subsurface water, Transmissivity, Mathematics, Linear programming, Analytical
techniques, Diffusion, Diffusivity.
An analysis of the inverse problem of parameter identification in unsteady
groundwater flow was presented. The response of the system is governed by a
typical nonlinear second - order partial differential equation for which there
exists no closed-form solution. Identification is an inverse process whereby
the parameters embedded in a differential equation are determined from observa-
tions of the system's input and output along with appropriate initial and boundary
conditions. These parameters are usually not physically measurable. A simple
but illustrative inverse problem was analyzed by quasilinearization, maximum
principle, gradient method, the influence coefficient method, and linear program-
ming. A comparison was made between these methods. The problem of convergence
and stability was examined and demonstrated by numerical experimentation.
75:02F-015
A HELE-SHAW ANALOG STUDY OF THE SEEPAGE OF GROUNDWATER RESTING ON A SLOPING BED,
Marei, S.M., Towner, G.D.
Cambridge University, (England). Department of Applied Biology.
Water Resources Research, Vol. 11, No. 4, p 589-594, August 1975. 5 fig, 8 ref.
Descriptors: *Model studies, *Seepage, *Groundwater, *Slopes, Aquifers, Ground-
water movement, Aquicludes, Dupuit-Forchheimer theory. Water table aquifers,
Equations, Height, Ditches, Discharge(Water), Viscosity.
The analysis derived from an application of the Dupuit-Forchheimer approximations
by Childs to the problem of flow of groundwater over sloping impermeable beds,
in which it is assumed that the streamlines are parallel to the sloping bed
rather than horizontal as previously assumed by Pavlovsky, was tested in a Hele-
Shaw analog. Seepage rates and water table positions were measured for a range
of slopes up to 30 degrees and with flow both up and down the slope. Considera-
bly better agreement was found, especially at the largest slopes, by using the
revised assumption. The theoretical seepage rates calculated from Childs1
analysis also lay between the limits given by an exact analysis due to Youngs,
in contrast to values calculated by using Pavlovsky's analysis which fell outside
the limits for large flow rates.
75:02F-016
A STOCHASTIC-CONCEPTUAL ANALYSIS OF ONE-DIMENSIONAL GROUNDWATER FLOW IN NONUNI-
FORM HOMOGENEOUS MEDIA,
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Freeze, R.A.
British Columbia University, Vancouver. Department of Geological Sciences.
Water Resources Research, Vol. 11, No. 5, p 725-741, October 1975. 19 fig, 1 tab,
37 ref.
Descriptors: *Stochastic processes, *Groundwater movement, *Non-uniform flow,
*Statistical models, Homogeneity, Porous media, Monte Carlo method, Saturated
flow, Parametric hydrology, Hydraulic conductivity, Compressibility, Porosity,
Distribution patterns, Spatial distribution, Aquifer characteristics, Correlation
analysis, Aquifers, Consolidation, Steady flow, Unsteady flow.
The most realistic representation of a naturally occurring porous medium is a
stochastic set of macroscopic elements in which the values of the three basic
parameters (hydraulic conductivity, compressibility, and porosity) are defined
by frequency distribution. All soils and geologic formations show random varia-
tions in the values of these parameters through space, and a measure of the
nonuniformity is provided by the standard deviation of the frequency distributions.
The analysis of groundwater flow in nonuniform media requires a stochastic-concep-
tual approach in which the effects of stochastic parameter distributions on pre-
dicted hydraulic heads are analyzed with the aid of a set of Monte Carlo solutions
to the pertinent boundary value problems. In this study, two one-dimensional
saturated flow problems were analyzed: steady state flow between two specified
heads and transient consolidation of a clay layer. The primary output was the
statistical distribution of hydraulic head. Results showed that the standard de-
viations of the input hydrogeologic parameters are important index properties.
For transient flow, the output distribution of hydraulic head values is almost
never normal. The results of the study questioned the validity of the underlying
assumption of deterministic groundwater modelling that a single value for each
flow parameter can define an 'equivalent' uniform porous medium.
75:02F-017
THE GALERKIN METHOD FOR NONLINEAR PARABOLIC EQUATIONS OF UNSTEADY GROUNDWATER
FLOW,
Yoon, Y.S., Yeh, W.W-G.
California University, Los Angeles. Department of Engineering Systems.
Water Resources Research, Vol. 11, No. 5, p 751-754, October 1975. 2 fig, 15 ref.
Descriptors: *Unsteady flow, *Equations, *Groundwater movement, *Finite element
analysis, Analytical techniques, Numerical analysis, Mathematical studies, Aqui-
fers, Surface-ground-water relationships, Homogeneity, Isotropy, Water table,
Specific yield, Hydraulic conductivity.
A relatively simple way was suggested for solving nonlinear parabolic partial
differential equations associated with unsteady groundwater flow. The Galerkin
formulation was discretized in the space domain by using piecewise polynomial
equations, and the trapezoidal formula was employed to approximate the time der-
ivative. The resulting system of nonlinear equations was then solved by the
Newton method. Rapid rate of convergence and easy computer implementation were
demonstrated by numerical examples. Results compared favorably with published
experimental data.
75:02F-018
COUPLED SATURATED-UNSATURATED TRANSIENT FLOW IN POROUS MEDIA: EXPERIMENTAL AND
NUMERIC MODEL,
Luthin, J.N., Orhun, A., Taylor, G.S.
California University, Davis. Department of Water Science and Engineering.
Water Resources Research, Vol. 11, No. 6, p 973-978. December 1975. 9 fig, 1
tab, 9 ref.
Descriptors: *Porous media, *Model studies, *Free surfaces, *Unsaturated flow,
*Unsteady flow, Numerical analysis. Analytical techniques, Flow nets, Groundwater,
Groundwater movement. Water wells, Potential flow, Moisture content, Computer
models, Dupuit-Forchheimer theory, Finite element analysis.
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Experimental data were obtained from a sector tank for the transient flow toward
a well. The data included both the saturated and the unsaturated flow region.
The data were used to verify the accuracy of a computer solution using an implicit
numerical procedure. Agreement between the two sets of data was good. The
computer solution can be adapted to a wide variety of groundwater flow problems.
75:02F-019
DETERMINING AQUIFER COEFFICIENTS FROM RESIDUAL DRAWDOWN DATA,
Vanden Berg, A.
Department of the Environment, Ottawa (Ontario). Inland Waters Directorate.
Water Resources Research, Vol. 11, No. 6, p 1025-1028, December 1975. 2 fig,
1 tab, 4 ref.
Descriptors: *Aquifer characteristics, *Transmissivity, *Storage coefficient,
*Least squares method, *Drawdown, Hydraulics, Aquifers, Groundwater, Permeability,
Porous media, Mathematical studies, Theis equation, Numerical analysis.
Hatush's equation for the drawdown in a leaky, infinite aquifer, adapted to the
residual drawdown, was used to obtain a least sum of squares fit to the residual
drawdown measurements in an observation well by iteratively adjusting the trans-
missivity, storativity, and leakage factor. First estimates for the least
squares method were obtained by first fitting the equation, with a fixed high
value of the leakage factor, to two points of the data; this was followed by a
number of fits to three points, each fit yielding a set of values for the three
aquifer coefficients; the set which yielded the least sum of squares was selected
as first estimate to the main routine. An application to data from a pump test
at Chatham, New Brunswick, was shown as an example.
75:02F-020
AN IDENTIFICATION APPROACH TO SUBSURFACE HYDROLOGICAL SYSTEMS,
Distefano, N., Rath, A.
California University, Berkeley. Department of Civil Engineering.
Water Resources Research, Vol. 11, No. 6, p 1005-1012, December 1975. 10 fig,
1 tab, 36 ref.
Descriptors: *Mathematical models, *Aquifer characteristics, *Transmissivity,
Model studies, Subsurface waters, Aquifers, Groundwater, Mathematical studies,
Observation wells, Hydrographs.
A method for the optimal determination of the transmissivity function in a model
of a horizontal two-dimensional saturated aquifer, using time histories of the
heads at a number of observation points, was developed. In this method the
transmissivity function was assumed to be represented by a continuous spline sur-
face over the entire domain of the aquifer and was given in terms of unknown nodal
values disposed over a rectangular grid. These nodal values were then determined
by requirements of optimality, i.e., by minimination of an error functional de-
noting the deviations of the observed and predicted heads at several strategically
distributed observation wells. The method was complemented by using a hierarch-
ical identification approach which consists of gradually increasing the number
of nodal values employed in the analytical representation of the transmissivity
function. Finally, a numerical example involving the determination of the trans-
missivity map of an aquifer by employing simulated head histories was presented
to illustrate the feasibility of the proposed method,
75:02F-021
FORECASTING WATER LEVELS IN AQUIFERS BY NUMERICAL AND SEMIHYBRID METHODS,
Hefez, E., Shamir, U., Bear, J.
Technion-Israel Institute of Technology, Haifa. Department of Civil Engineering.
Water Resources Research, Vol. 11, No. 6, p 988-992, December 1975. 3 fig, 3 tab,
13 ref.
Descriptors: *Forecasting, *Water levels, *Aquifers, *Numerical analysis, *Hybrid
computers, Model studies, Computer models, Resistance networks, Equations, Bounda-
ries (Surf aces) , Artesian heads, Transmissivity, Recharge, Water wells, Analog
models.
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Two methods which employ a cell model for forecasting water levels in aquifers
were compared: the (noniterative) alternating direction implicit (ADI) finite
difference method and a semihybrid iterative method, in which a resistor network
is the analog part. By using simulation of the semihybrid method it was concluded
that this method requires a larger computational effort than the ADI method.
75:02F-022
IDENTIFYING THE PARAMETERS OF AN AQUIFER CELL MODEL,
Hefez, E. , Shamir, U., Bear, J.
Technion-Israel Institute of Technology, Haifa. Department of Civil Engineering.
Water Resources Research, Vol. 11, No. 6, p 993-1104, December 1975. 6 fig,
6 tab, 53 equ, 15 ref.
Descriptors: *Aquifers, *Parametric hydrology, *Hydrologic data, *Forecasting,
Water levels, Groundwater, Transmissivity, Linear programming, Optimization,
Equations, Mathematical models, Systems analysis, Constraints.
Cell models are commonly used for forecasting water levels in aquifers. Cali-
bration of such models is achieved through identification of their parameter
values, the transmissivities and storativities of all cells, using historical
data. Several methods of formulating the identification as a linear or quadratic
programming problem are presented. The aquifer is represented by a finite dif-
ference model. The proposed methods have been tested on synthetic models, the
parameters of which were a priori known. Examples are given, results of the
various methods compared, and the sensitivity of these results to errors in the
data is discussed. Inflows or outflows during historical periods may also be
determined by the same methods; an example for a real aquifer is presented.
75:02F-023
THE EFFECT OF CLIMATE ON THE CHEMISTRY OF CARBONATE GROUNDWATER,
Drake, J.J., Wigley, T.M.L.
McGill University, Montreal (Quebec). Department of Geography.
Water Resources Research, Vol. 11, No. 6, p 958-962, December 1975. 1 fig, 35 ref.
Descriptors: *Geochemistry, *Carbon dioxide, *Carbonates, *Aquifer characteris-
tics, *Climates, *Model studies, Temperature, Chemistry, Carbonate rocks. Dolomite,
Limestones, Calcite, Bicarbonates, Groundwater, Soil water, Soil chemistry,
Water chemistry, Water quality, Subsurface waters, Erosion rates, North America.
The temperature coefficient of the log P sub C02-temperature relationship for
springwater from carbonate terrains in North America is approximately 0.07/C.
Consideration of a simple model of soil air behavior and various published data
suggested that the temperature coefficient of the same relationship for soil air
is of the order of 0.04/C. A model where the soil zone is the source of carbon
dioxide for water entering a groundwater system and where the subsequent chemical
evolution of the water occurs under closed system conditions was consistent with
these relationships.
75:02F-024
NORMAL MODE ANALYSIS OF THE LINEAR EQUATION OF GROUNDWATER FLOW,
Nutbrown, D.A.
Department of the Environment, Reading (England). Central Water Planning Unit.
Water Resources Research, Vol. 11, No. 6, p 979-987, December 1975. 6 fig, 1 tab,
3 ref.
Descriptors: *Base flow, *Mathematics, *Numerical analysis, *Computer models,
*Unsteady flow, Equations, Groundwater movement, Confined water, Diffusion,
Theis equation, Model studies, Simulation analysis, Hydrology.
The study of groundwater flow, given equations of motion and boundary conditions
which are mathematically linear, can be analyzed by using a normal mode approach.
For the fully continuous case the simplest example is the familiar double Fourier
21
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analysis. Analogous results exist for the semidiscrete case, in which only time
is treated as a continuous variable, and a method can be given for computing
normal modes whose corresponding recession factors lie within prescribed ranges.
One application of this approach suggested an empirical form for the base flow
component of a stream hydrograph. The fully discrete case was also treated and
provided a convenient basis for the comparison of the more common approximations
to the solution of the transient groundwater flow equation. In particular, it
was shown why the study of model problems does not provide a useful guide to the
accuracy of the alternating direction implicit method applied to more general sit-
uations.
75:02F-025
THE USE OF ENVIRONMENTAL TRITIUM TO ESTIMATE RECHARGE TO A SOUTH-AUSTRALIAN
AQUIFER,
Allison, G.B., Hughes, M.W.
Commonwealth Scientific and Industrial Research Organization, Glen Osmond (Austra-
lia) . Div- of Soils.
Journal of Hydrology, Vol. 26, No. 3/4, p 245-254, August 1975. 4 fig, 1 tab,
7 ref.
Descriptors: *Tritium, *Groundwater recharge, *Australia, Groundwater movement,
Aquifers, Hydrogeology, Soil moisture, Sinks, Hydraulic gradient, Model studies,
Mathematical models, Equations, Dispersion, Potentiometric level. Irrigation,
Correlation analysis, Pumping, Evapotranspiration.
The tritium concentration of groundwater samples has been used to estimate the
amount of water moving laterally into an aquifer as well as the quantity of
local recharge. A multicompartment model used to calculate the variation of
tritium concentration within the aquifer predicts that the lateral input of water
is 24,000,000 cu m/yr, while local recharge is 27 mm/yr. These results are com-
pared with conventional hydrogeological estimates of 18,000,000 cu m/yr and 70
mm/yr, respectively.
75:02F-026
AQUIFER EVALUATION USING DEPOSITIONAL SYSTEMS: AN EXAMPLE IN NORTH-CENTRAL
TEXAS,
Hall, W.D., Turk, L.J.
Dames and Moore, Boca Raton, Florida.
Ground Water, Vol. 13, No. 6, p 472-483, November-December, 1975. 15 fig, 3 tab.
Descriptors: *Hydraulic properties, *Deltas, *Water chemistry, Permeability,
Aquifer characteristics, Hydrochemical properties, Ion exchange, *Texas, Ground-
water movement, Deposition(Sediments).
Delineation of major depositional systems and their component facies within the
Lower Cretaceous Hosston and Hensel Sandstone Formations provides a model for
predicting the distribution and chemical composition of water in the aquifer.
Two major depositional trends occur in both formations: (1) a dip-oriented mean-
derbelt fluvial system which supplied sediment to (2) a strike-oriented delta
system in the east. The meanderbelt sandstone facies of the fluvial systems and
the coastal barrier facies of the delta systems are capable of supplying greater
amounts of ground water than the floodbasin, lagoon-marsh-embayment, or prodelta/
shelf facies. Chemical analysis of ground water suggests correlation between the
hydrochemical facies and depositional facies. Ground water is dominantly of the
calcium-magnesium bicarbonate type in the fluvial systems. The chemical character
of the water changes downdip to sodium sulfate and sodium bicarbonate types in the
delta systems. The change in chemical equilibrium probably occurs as dolomite-
rich waters from the fluvial facies percolate downdip and dissolve anhydrite or
oxidize pyrite in lagoonal facies within the delta system. Calcium may be ex-
changed for sodium on the marine clays.
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75:02F-027
OZONATION OF AMMONIA IN WASTEWATER,
Singer, P.C., Zilli, W.B.
North Carolina University, School of Public Health, Department of Environment
Sciences and Engineering, Chapel Hill, N.C.
Water Research, Vol. 9, No. 2, p 127-134, February 1975. 9 fig, 4 egu, 1 tab,
10 ref.
Descriptors: *Waste water, *0zone, *Ammonia, Waste water treatment, Phosphate.
An investigation of the effects of ozone on ammonia in municipal wastewaters is
described and discussed relative to the application of ozone for advanced waste
treatment. Ammonia is oxidized completely to nitrate, thereby eliminating the
nitrogenous oxygen demand of the waste. In buffered solutions of ammonium chlor-
ide, the reaction is first-order with respect to the concentration of ammonia
and the rate increases with increasing pH over the range 7-9, and with increasing
ozone partial pressure.
75:02F-028
THE USE OF A SPECIALIZED DRILLING AND GROUND-WATER SAMPLING TECHNIQUE FOR DELINE-
ATION OF HEXAVALENT CHROMIUM CONTAMINATION IN AN UNCONFINED AQUIFER, SOUTHERN
NEW JERSEY COASTAL PLAIN,
Yare, B.S.
Woodward-Clyde Consultants, 1373 Broad Street, Clifton, New Jersey 07012.
Ground Water, Vol. 13, No. 2, p 151-154, March-April 1975. 4 fig, 1 tab, 5 ref.
Descriptors: *Chromium, *Water pollution, Groundwater, Water sampling, Water
quality, Water quality control, New Jersey.
Consultants were retained to investigate a ground-water contamination problem
caused by disposal of chromium-laden process water into an unlined lagoon in the
Coastal Plain sediments of southern New Jersey. During the course of the inves-
tigation, a technique for sampling of formation water at specific horizons during
drilling was developed. This technique consists of the following procedure: (1)
drilling a borehole to the base of a sampling horizon; (2) lowering a wire-wound
well screen and riser pipe to the bottom of the borehole and gravel-packing the
screen; (.3) pumping the borehole well until the discharge is clear of drilling
fluid; and (.4) pumping at least 100 gallons of formation water before collecting
the sample and performing field water quality tests.
75:02F-029
EARTH RESISTIVITY SURVEYS - A METHOD FOR DEFINING GROUND-WATER CONTAMINATION,
Stollar, R.L., Roux, P.
Geraghty & Miller, Inc., 44 Sintsink Drive East, Port Washington, New York 11050.
Ground Water, Vol. 13, No. 2, p 145-150, March-April 1975, 4 fig, 10 ref.
Descriptors: *Groundwater, *Pollution, Groundwater resources, Water quality,
Water quality control, Water pollution, Water sampling.
An important part of every investigation of ground-water pollution is to locate
and define the extent of the contaminated body of ground water. The usual method
for accomplishing this is to install and sample numerous test wells, a costly and
time-consuming procedure. A much faster and less costly method, which has proven
to give accurate results, is the earth resistivity survey. Because earth resis-
tivity is inversely proportional to ground-water conductivity, the location of
ground water that has been contaminated by a relatively high concentration of
conductive industrial wastes, for example, may be quickly and accurately traced.
75:02F-030
THEORY OF GROUND-WATER RECHARGE FOR A STRIP BASIN,
Amar, A.C.
Faculty of Military Studies, University of New South Wales, Duntroon, A.C.T.,
2600, Australia.
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Ground Water, Vol. 13, No. 3, p 282-292, May-June 1975. 9 fig, 14 equ, 16 ref,
2 append.
Descriptors: *Model studies, *Groundwater, *Groundwater recharge, *Groundwater
resources, *Dupuit-Forchheimer theory.
Formulation and solution of one-dimensional analytical and computational models,
linear as well as nonlinear, pertaining to a typical ground-water recharge pattern
are presented. The objective of this investigation is to direct attention toward
an evaluation and correlation of the various theoretical models based on the
Dupuit-Forchheimer (D-F) approximations for the unsteady hydrodynamic behavior
of the proposed recharge system under saturated flow conditions. Comparisons
with the pertinent experimental data, presented in the form of dimensionless graphs,
indicate that the linear D-F theory is valid for relatively small water-table rises
but for large rises it predicts substantially greater rises than actually occur,
particularly beneath and in the vicinity of the recharge basin. The range of
validity is considerably improved Between theory and experiments for relatively
large rises using the nonlinear theory,
75:02F-031
APPROXIMATION FOR STEADY INTERFACE BENEATH A WELL PUMPING FRESH WATER OVERLYING
SALT WATER,
Haubold, R.G.
Colorado Division of Water Resources, Denver, Colorado 80203.
Ground Water, Vol. 13, No. 3, p 254-259, May-June 1975. 3 fig, 1 tab, 9 equ,
12 ref.
Descriptors: *Saline water, *Saline water intrusion, Saline water systems, Saline
water-freshwater interfaces, Mathematical studies, Aquifers, Groundwater.
A mathematical expression was developed which would approximate the steady position
and shape of a sharp, upconed interface between fresh and salt water in an aqui-
fer when the fresh water only is being pumped from a well. The computation of
the interface shape was based on an empirically derived modification of Muskat's
approximation for the height of the cone beneath a well. Differing depths of well
penetrations and their effect on the upconed interface were investigated with the
approximation. The computed interfaces were compared with corresponding inter-
faces determined experimentally in a Hele-S.haw model. Close agreements could be
achieved for interfaces which penetrated as much as 50% of the distance between
the bottom of the well and the initial interface position. Changing the length
of the producing interval of the well while keeping its pumping rate constant did
not have a significant influence on the shape or position of the upconed interface.
Even though the shape and position of the upconed interface could be approximated,
a refinement of the analytical methods used in deriving the approximation for the
interface may be necessary before it can be applied reliably.
75:02F-032
ECONOMIC IMPACTS OF STATE ENVIRONMENTAL PROGRAMS IN A NATIONAL FRAMEWORK: THE
IOWA CONSERVANCY LAW,
Heady, E.O., Nagadevara, V.S.S.V.
Iowa State University, Ames 50010.
Journal of Soil and Water Conservation, Vol. 30, No. 6, p 272-278, November-Decem-
ber, 1975. 3 fig, 5 tab, 8 ref.
Descriptors: legislation, *Iowa, *Sediments, *Erosion, Economics, Economic
justification.
Several states have passed laws to protect prime farm land, reduce environmental
impacts, or eliminate off-site sediment damages. The 1971 Iowa legislature, for
example, passed the Conservancy District Act to control the use of soil and water
resources and thereby limit annual soil loss. Because of the inelastic demands
for farm commodities, one state such as Iowa may restrain land use with the result
that its farmers sacrifice income while farmers elsewhere gain income. We applied
national models to determine what the outcome would be if Iowa were to fully imple-
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ment its Conservancy District Act or apply other environmental restraints, such as
limiting nitrogen and pesticide use. The results show that in all cases restraints
implemented solely in Iowa would reduce net farm income in the state while income
elsewhere in the nation would increase. Hence, national as opposed to state le-
gislation is implied for the long run.
75:02F-033
A SIMPLE CASE OF CONJUNCTIVE SURFACE-GROUND-WATER MANAGEMENT,
Morel-Seytoux, H.J.
Colorado State University, Fort Collins, Colorado 80521.
Ground Water, Vol. 13, No. 6, p 506-515, November-December 1975. 1 fig, 2 tab,
38 equ, 21 ref, 2 append.
Descriptors: *Model studies, *Hydrology, Hydrologic system, Groundwater resources,
Groundwater basins, Legislation.
A specific hydrologic model of a stream-alluvial aquifer system was developed for
the purpose of designing rules and regulations which maximize the beneficial uses
of the waters of a State within the law. The model is particularly suited when
decisions on pumping rates are to be reviewed on a frequent regular basis. The
procedure is illustrated on a simplified case for which the river loss influence
coefficients can be obtained by a combination of analytic derivations and algebra-
ic manipulations.
75:02F-034
WATER ZONING - TOOL FOR GROUND-WATER BASIN MANAGERS,
Dutcher, L.C., Peterson, L.R.
United States Geological Survey, Denver, Colorado 80225.
Ground Water, Vol. 13, No. 5, p 395-399, September-October 1975. 5 ref.
Descriptors: *Groundwater, *Groundwater availability, *Groundwater basins, *Ground-
water resources, *Water zoning, Water conservation.
Water zoning is not new in arid areas. Many States have laws limiting pumping.
However, most of the existing ordinances do not achieve their state purpose. Many
enforce conservation of scarce resources for benefit of future users. Some pur-
port to ensure a continuous water supply to the rights holders. Existing ordinan-
ces that limit pumping to the so-called safe yield do not take costs or recover-
able benefits into consideration, and the period of use is not stipulated. There-
fore where pumping is regulated under such ordinances, the basins cannot be managed
to obtain maximum benefits to present users of the available supply. Two types
of ordinances are discussed: general-purpose and management-plan ordinances,
which are designed to make possible the achievement of specific objectives. Ex-
amples are given of how the latter can be designed to: limit stream depletion and
protect existing rights; disperse pumping to increase economic return; force
conjunctive use of all land, mineral, and water resources; and establish produc-
tion quotas to insure optimum economic return to all users during a predetermined
period.
75:02F-035
DIURNAL FLUCTUATIONS OF WATER TABLES INDUCED BY ATMOSPHERIC PRESSURE CHANGES,
Turk, L.J.
Texas University, Austin. Department of Geological Sciences.
Journal of Hydrology, Vol. 26, p 1-16, 1975. 8 fig, 37 ref.
Descriptors: *Water table, *Aquifers, *Utah, *Atmospheric pressure, Groundwater.
The shallow water table at the Bonneville Salt Flats, Utah, fluctuates 1.5-6.0 cm
per day during the summer, and 0.5-1.0 cm per day during the winter. Highest water
levels occur in late afternoon, whereas lowest levels occur in mid-morning. Simi-
lar fluctuations are attributed to temperature-related atmospheric pressure changes
acting on the capillary zone. This proposed mechanism involves the transfer of
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water from below the water table to the capillary fringe in response to lower
pressure, and transfer of water from the capillary fringe to the water table in
response to higher pressure. Rapid volume changes of air entrapped in the capil-
lary pores account for the expulsion or infusion of capillary water. Laboratory
experiments with an artificial aquifer confirm that such fluctuations can occur
rapidly when the only variable is pressure. In this case no intervening confining
layer exists, so the mechanism is distinctly different from the mechanism which
causes blowing wells.
75:02F-036
THE KINETICS OF MINERAL DISSOLUTION IN CARBONATE AQUIFERS AS A TOOL FOR HYDROLOGI-
CAL INVESTIGATIONS, I. CONCENTRATION-TIME RELATIONSHIPS,
Mercado, A., Billings, G.K.
New Mexico Institute of Mining and Technology, Socorro, N.M. Department of Geosci-
ence.
Journal of Hydrology, Vol. 24, p 303-331, 1975. 9 fig, 2 tab, 54 egu, 29 ref.
Descriptors: *Aquifers, Hydrologic systems, Hydrologic properties, Carbonates,
Model studies, Groundwater, Water quality.
Groundwater chemical analyses, water level maps, and results of pumping tests are
sufficient for studying the relationships between the major geochemical and hydro-
logic processes in a groundwater system. The importance of available groundwater
chemical data for hydrologic investigations has been relatively neglected. Two
general courses exist for use of groundwater chemical data and dissolution kinetics
in hydrologic investigations: (1) estimating relative ages according to precali-
brated concentration-time relationships similar to that of tritium and 14C dating
techniques; and (2) integrated study of both hydrologic and geochemical phenomena
with the aid of combined hydrogeochemical models. In this paper, a kinetic model
for the dissolution of multimineral assenblages in porous media is derived with
special emphasis on the simultaneous dissolution of calcite, dolomite and gypsum
in some carbonate aquifers.
75:02F-037
TRANSFORMATIONS OF FLUXES AND FORCES DESCRIBING THE SIMULTANEOUS TRANSPORT OF
WATER AND HEAT IN UNSATURATED POROUS MEDIA,
Raats, P.A.C.
Agricultural Research Service, Riverside, California.
Water Resources Research, Vol. 11, No. 6, p 938-942, December 1975. 18 ref.
Descriptors: *Subsurface flow, *Porous media, *Heat transfer, *Analytical tech-
niques, *Groundwater, Unsaturated flow, Mathematical studies, Equations, Hydrother-
mal studies, Temperature, Thermal water, Heat, Diffusivity.
Balances of mass for the water in n distinct phases and a balance of heat for the
medium as a whole were formulated. Following Philip and de Vries, it was assumed
that the flux of water in each phase is proportional to the gradient of the
pressure in that phase and that the diffusive component of the flux of heat is pro-
portional to the gradient of the temperature. Clapeyron equations were used to
express the gradient of the pressure in any phase in terms of the gradient of the
pressure in a reference state and of the temperature. The reference state may be
the water in one of the phases or the water in some measuring device such as a
tensiometer or a psychrometer. Expressions for the total flux of water and for the
diffusive flux of heat plus the convective flux of heat associated with the conver-
sion from any phase to the reference state were shown to satisfy the Onsager
reciprocal relations. A theorem due to Meixner was used to delineate the class
of fluxes and forces that preserves these relations. In particular, it was shown
that if the gradients of water content and temperature are used as the driving
forces, the Onsager relations are no longer satisfied.
75:02F-038
COMPARATIVE STUDY OF FRESH-SALT WATER INTERFACES USING FINITE ELEMENT AND SIMPLE
APPROACHES,
Kashef, A-A. I., Safar, M.M.
26
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North Carolina State University, Raleigh, NC
Civil Engineering Department.
Water Resources Bulletin, Vol. 11, No. 4, p 651-665, August 1975. 3 fig, 4 tab,
26 egu, 15 ref, 1 append.
Descriptors: *Saline water-freshwater interfaces, Artesian aquifers, Aquifer
management, Aquifer systems, Aquifers, Groundwater, Water resources. Water quality.
The fresh-salt water interface in artesian aquifers has been investigated by
various techniques on the basis of its analogy to the free surface in earth dams
or cores of dams. Although various approximations are used, some more or less
exact solutions exist. One of the simple methods, that would appeal to practical
workers, was developed by the analysis of hydraulic forces. However, this method
has not been checked thoroughly due to the lack of wide ranges of coverage by the
more or less exact solutions. In this paper a suggested finite element method is
used for the purpose of comparing with the method of hydraulic forces. The pre-
sented procedure eliminates some of the difficulties and uncertainties in current
finite element procedures. Both methods proved to be in close agreement. More-
over, the hydraulic heads along the upper boundary of the artesian aquifer were
found to be in close agreement with Dupuit's equation. The results of this in-
vestigation would greatly simplify the more complex management problems when the
effects of discharge and/or recharge wells are added to the natural flow effects.
27
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Section VII
WATER CYCLE
WATER IN SOILS (GROUP 02G)
75:02G-001
SIMULATION OF MISCIBLE DISPLACEMENT IN SOILS USING THE METHOD OF CHARACTERISTICS,
Smajstrla, A.G., Reddel, D.L., Hiler, E.A.
Texas A and M University, Colege Station. Department of Agricultural Engineering.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 2,
p 281-287, March-April 1975. 9 fig, 27 ref, 1 append.
Descriptors: *Simulation analysis, *Mathematical models, *Porous media,
*lnfiltration, *Soils, Computer programs, Model studies, Management, Darcys law,
Dispersion, Saturated flow, Unsaturated flow, Solutes, Saturated soils, Moisture
content, Homogeneity, Steady flow, Unsteady flow.
A simulation model was developed to simulate miscible displacement of a con-
servative solute during one-dimensional vertical infiltration into a homogeneous,
isotropic, porous media. Solutions of transient flow problems were obtainable
as well as steady state problems because it was not necessary to assume constant
solution fluxes to solve the dispersion equation. The accuracy of the simulation
results from the literature. Comparisons provided excellent agreement in all
cases except for Warrick's field experimental data. Considering the nonhomo-
geneous field conditions encountered in Warrick's experimental plot, the
simulated results were considered to be good.
75:02G-002
PLANNING IRRIGATION AND DRAINAGE SYSTEMS USING RETENTION AND EXTRACTION LIMITS,
Campbell, M.D., Lembke, W.D.
Bureau of Reclamation, Denver, Colorado.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 3,
p 514-517, May-June 1975. 8 fig, 15 ref.
Descriptors: *Irrigation, *Drainage, *Planning, Irrigation engineering,
Drainage engineering, Model studies.
Rather than explaining that water held in the soil between field capacity and
the wilting percentage is available for plant growth and then trying to define
field capacity and wilting percentage to suit our needs, we choose to define
two new range limits and show how use of these limits can provide for efficient
use of water and maximum plant growth. We will use data reported by Denmead and
Shaw (1962) and a model developed by Campbell (1972) to display the ideas
associated with these limits.
75:02G-003
NITRATE REDUCTION AND ASSOCIATED MICROBIAL POPULATIONS IN A PONDED HANFORD
SANDY LOAM,
Volz, M.G., Belser, L.W., Ardakani, M.S., McLaren, A.D.
California University, Berkeley, Department of Soils and Plant Nutrition
Journal of Environmental Quality, Vol. 4, No. 1, p 99-102, January-March 1975.
1 fig, 3 tab, 21 ref.
Descriptors: *Nitrate, *Denitrification, Soils, Soil investigations, Soil
bacteria, Nitrite.
A field plot of Hanford sandy loam was ponded for 2 weeks with a solution of
KN03 and Ca (N03)2 containing 100 ppm NO3-N in order to measure short term
denitrification rates as well as growth and distribution of bacteria capable of
reducing nitrate to nitrite and/or N2O and N2. Denitrifying bacteria generally
decreased in number with depth and time and were not as numerous as nitrate
reducers.
28
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75:02G-004
AGRICULTURAL DRAINAGE RESEARCH NEEDS AND PRIORITIES, 1974
Carter, C.E., Donnan, W.W., King, L.G-, Schwab, G.O.
Agricultural Research Service, United States Department of Agriculture,
Baton Rouge, La.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No.
3, p 529-534, May-June 1975. 3 tab.
Descriptors: *Drainage, *Drainage engineering, *Research priorities. Agriculture.
Drainage research has played an important role in increasing food and fiber
production in the United States. In the Future its importance is expected
to increase as farmers attempt to increase crop yield per acre to meet the
increased demands for food and fiber both at home and abroad. Results of a
survey made during 1973 to 1974 to determine drainage research needs in the
United States is reported in this paper.
75:02G-005
A MATHEMATICAL MODEL FOR PHOSPHORUS MOVEMENT IN SOILS,
Shah, D.B., Coulman, G.A., Novak, L.T., Ellis, E.G.
Michigan State University, East Lansing, Department of Chemical Engineering.
Journal of Environmental Quality, Vol. 4, No. 1, p 87-92, January-March 1975.
3 fig, 16 ref. 1 append.
Descriptors: *Model studies, *Phosphorus, Soil investigations, Soils, Soil
properties, Waste disposal.
Land application of municipal and industrial wastes is increasingly being looked
upon as an alternative for treatment of the effluent. Since phosphorus compounds
constitute a major potential source of ground water contamination, it is important
to study the movement of these compounds in the soil. In this paper, a' model
for the movement of P has been developed. Material balance equations for water
in the soil pore spaces, P in the liquid phase, and adsorbed P on the soil have
been formulated. These equations are solved numerically to simulate the P
concentration profiles in the soil solution and in the soil as functions of
depth for an operating waste disposal system. The results of the simulation
show a good agreement with the field data. The model can be used to determine
the response of the system for a given input of phosphates and thus is a useful
tool in the design and management of such systems.
75:02G-006
PHOSPHORUS MOVEMENT IN SOILS: THEORETICAL ASPECTS,
Novak, L.T., Adriano, D.C., Coulman, G.A., Shah, D.B.
Cleveland State University, Cleveland, Ohio, Department of Chemical Engineering
Journal of Environmental Quality, Vol. 4, No. 1, p 93-00, January-March 1975.
4 fig, 5 tab, 16 ref, 1 append.
Descriptors: *Waste water, *Model studies, *Phosphorus, *Soils, Soil investi-
gations, Agriculture, Mathematical models.
The renovation of waste water by land application shows promise because of the
potential to use certain waste water nutrients to fertilize agricultural crops
and to recycle these nutrients as agricultural products. In order to locate,
design, and manage land treatment processes, quantitative descriptions of
critical processes are required. The adsorption of P by soils is a critical
process which needs to be considered. This paper compares a new model for P
movement in soils with existing adsorption-desorption models developed for
chromatography and ion exchange processes. The effect of the model parameters
on P movement in soils is also examined. From the new model considered here,
it was found that under P adsorption, a P profile of fixed shape (shock layer)
developed and moved through the soil at a speed which could be calculated from
the P Langmuir adsorption isotherm, density of the soil, and the P rate of
application to the soil.
29
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75:02G-007
DRAIN ENVELOPE RESPONSE TO FIELD TREATMENTS,
Willardson, L.S., Davis, S., Mulder, D., Spencer, J.R.
Imperial Valley Conservation Research Center, Brawley, CA
Transactions of the American Society of Agricultural Engineers, Vol. 18,
No. 1, p 134-136, January-February 1975. 6 fig, 2 ref.
Descriptors: *Drains, *Drainage, *Drainage engineering, *Drainage systems.
One of the principal reasons for installing a drain envelope is to decrease
hydraulic resistance in the vicinity of the drain openings. This experiment
has shown that contamination of the envelope material with fine particles,
whether naturally occurring or added during installation, causes the hydraulic
conductivity of a drain envelope to decrease drastically. Furthermore, conditions
are created which may result in a discharge rate decreasing with time. A
drain with a clean, well-graded envelope will accept water without a water table
build-up over the drain. A water table above a drain indicated a back pressure
in the drain or a high hydraulic resistance in the envelope. In the experiment,
the latter cause was the reason for poor drain envelope performance but both
conditions should be avoided. The results of the experiment have led to the
following conclusions: (a) As little as 5 percent of field soil in the envelope
material seriously reduces drain envelope performance, (b) flooding trenches
for consolidation of backfill material does not significantly affect drain
envelope performance, and (c) high-pressure jet cleaning of drains improves
hydraulic performance of drain envelopes.
75:02G-008
SIMULTANEOUS TRANSPORT OF WATER AND ABSORBED SOLUTES THROUGH SOIL UNDER
TRANSIENT FLOW CONDITIONS,
Davidson, J.M., Baker, D.R., Brusewitz, G.H.
Florida, Gainesville, Department of Soil Science
Transactions of the American Society of Agricultural Engineers, Vol. 18,
No. 3, p 535-539, May-June 1975. 4 fig, 24 ref.
Descriptors: *Simulation analysis, Soilwater movement, Soil investigations,
*Solutes, Model studies.
A set of differential equations for water and interacting and noninteracting
solute transport were solved simultaneously for transient and steady state
soil water conditions using a finite difference scheme. The solutions used
independently measured soil and soil-solute adsorption-desorption character-
istics to describe the movement of a solute in a soil profile. Numerical
dispersion in the finite difference solution of the so*Lute transport equation was
considered and a correction included in the solution. Experimental results
from a laboratory study were used to test the numerical solution's ability to
describe the movement and distribution of a herbicide in a soil profile with
time. A natural field problem involving infiltration and evaporation was
simulated and discussed. The agreement between laboratory and calculated
water and herbicide distributions was good.
75:026-009
WATER INTAKE UNDER CENTER-PIVOTS FROM TIME-VARYING APPLICATION RATES,
Addink, J.W., Miles, D.L., Skogerboe, G.V.
Nebraska University, Lincoln, Department of Agricultural Engineering.
Transactions of the American Society of Agricultural Engineers, Vol. 18,
No. 3, p 523-525, May-June 1975. 4 fig, 3 tab, 14 ref.
Descriptors: *Model studies, *Sprinkler irrigation, Irrigation, Irrigation
engineering, Infiltration, Infiltration rates.
Design considerations of center-pivot sprinkler systems are different than
those for conventional systems. Stationary sprinkler system design is primar-
30
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ily concerned with uniformity of water application. Sprinklers are selected so
that application rates do not exceed intake rates. One approach to water intake
problems is numerical solution of moisture flow equations. One of the earlier
published solutions considered horizontal and vertical flow from a constant
surface saturation (Klute 1952). The techniques have become more sophisticated
with time. Smith and Woolhiser (1971) included rainfall and ponded conditions
and overland flow resulting from runoff. This paper presents results of runoff
studies using the model of Smith and Woolhiser (1971) and laboratory studies.
75:02G-010
RATE OF CHLORIDE AND WATER MOVEMENT IN SOUTHERN CALIFORNIA SOILS,
Tullock, R.J., Coleman, N.T., Pratt, P.F.
California University, Riverside, Department of Soil Science and Agricultural
Engineering.
Journal of Environmental Quality, Vol. 4, No. 1, p 127-131, January-March 1975.
3 fig, 3 tab, 25 ref.
Descriptors: *Chlorides, *Soils, *Soil investigations, *Soil water movement,
California, Columns.
Column experiments in the laboratory showed an increase of 2 to 25% in the
relative rate of chloride movement in soils to water when the movement of
water was calculated on a total pore-volume basis. The increase was explained
as a result of anion exclusion next to the surfaces of negatively charged soil
colloids. The relative rate of flow was decreased when the moisture retained
by the air dry soils was deleted from the total pore solution. For soils
containing sufficient clay to result in a cation exchange capacity greater than
10 meq/lOOg, an equation was developed relating the fraction of the pore
solution in equilibrium with anions to the cation exchange capacity. Calculated
transit times for anion movement from the soil surface to ground waters should
include a correction for the volume of exclusion.
75:02G-011
OCCURRENCE OF 2,4,5-T and PICLORAM IN SUBSURFACE WATER IN THE BLACKLANDS OF TEXAS
Bovey, R.W., Burnett, E., Richardson, C., Baur, J.R., Merkle, M.G.
Journal of Environmental Quality, Vol. 4, No. 1, p 103-106, January-March 1975.
1 fig, 7 tab, 12 ref.
Descriptors: *Herbicides, *Lysimeters, *Groundwater, Watershed(Basin), Water
quality, Pollutants, Subsurface waters.
This investigation was conducted to determine the concentration of 2, 4, 5-T
((2,4,5-trichlorophenoxy) acetic acid) and picloram (4-amino-3,5,6-trichloro-
picolinic acid) in subsurface water after spray applications of the herbicides
to the surface of a seepy area watershed and lysimeter in.the Blacklands of
Texas. A 1:1 mixture of the triethylamine salts of 2, 4, 5-T + picloram was
sprayed at 2.24 kg/ha every 6 months on the same area for a total of five appli-
cations. Herbicide content in the Houston Black clay during the study ranged
from 0 to 162 ppb. Herbicide content on grass was high immediately after spray-
ing, but degraded rapidly after each treatment. Concentration of 2, 4, 5-T and
picloram in seepage and well water from the treated area was extremely low
(less than 1 ppb) during the 3-year study- No 2, 4, 5-T was detected from 122
drainage samples from a field lysimeter sampled for 1 year after treatment with
1.12 kg/ha of 2, 4, 5-T + picloram (1:1). Picloram was detected in small amounts
(1 to 4 ppb) 2 to 9 months after treatment in lysimeter water.
31
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75:020-012
ESTIMATING INFILTRATION FOR ERRATIC RAINFALL,
Reeves, M., and Miller, E.E.
Oak Ridge National Laboratory, Tennessee.
Water Resources Research, Vol. 11, No. 1, p 102-110, February 1975. 14 fig.
1 tab. 11 ref. 2 append.
Descriptors: *Infiltration, *Rainfall intensity, *Soil water movement, *Math-
ematical models, *Estimating, Groundwater movement, *Rainfall-runoff relationships,
Runoff, Seepage, Simulated rainfall, Soil water, Infiltration rates, Hysteresis,
Soil physical properties, Precipitation intensity, Hydrology, Watersheds(Basins),
Storms.
To cheaply estimate the infiltration/runoff of typically unsteady rainfall events
for purposes of watershed modeling, a method known as 'time compression1 was
tested against hysteretic Darcy computations. This method assumes that for a
given soil the maximum infiltration rate is simply a function of the cumulative
infiltration, regardless of the rainfall versus time history. The appraisal
proved generally encouraging for application of this approximation to watershed
modeling. The maximum infiltration rate was uniformly underestimated to a
moderate degree in the early minutes of a downpour commencing late in an unsteady
event.
75:02G-013
A THERMODYNAMIC INTEGRAL EQUATION FOR THE EQUILIBRIUM MOISTURE PROFILE IN
SWELLING SOIL,
Sposito, G.
Arizona Water Resources Research Center, Tucson.
Water Resources Research, Vol. 11, No. 3, p 499-500, June 1975. 10 ref.
Descriptors: *Soil moisture, *Thermodynamics, *Equilibrium, *Equations, Solutes,
Profiles, Water table, Entropy, Temperature, Bulk Density, Porous media.
The methods of thermodynamics were employed to develop a nonlinear integral
equation for the equilibrium moisture profile in a swelling soil which was
assumed to be uniform in the distribution of dissolved substances. The equa-
tion was shown to be identical with an expression suggested (but not derived)
by Philip in response to criticism of his discussion of the hydrostatics of
swelling porous media.
75:02G-014
CONVERGENCE AND VALIDITY OF TIME EXPANSION SOLUTIONS: A COMPARISON TO EXACT AND
APPROXIMATE SOLUTIONS,
Parlange, J-Y
Connecticut Agricultural Experiment Station, New Haven. Department of Ecology
and Climatology.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 3-6, January-
February 1975. 1 fig, 12 ref.
Descriptors: *Mathematical studies, *Equations, *Diffusion, Saturated flow,
Saturated soils, Porous media, Infiltration, Diffusivity, Boundaries(Surfaces),
Absorption.
The convergence of series solutions for the diffusion equation by time expansion
was discussed quantitatively, on the basis of the linear and delta function solu-
tions for a spherical cavity. It was shown that convergence alone is a poor
criterion to justify the validity of the series solutions. A counter example,
diffusion in the presence of an impervious wall, showed that the series may con-
verge for all times but be entirely erroneous. By comparison, an approximate
integral technique yields a solution which agrees very well with the exact result.
32
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75:02G-015
EFFECT OF APPLICATION RATE, INITIAL SOIL WETNESS, AND REDISTRIBUTION TIME ON
SALT DISPLACEMENT BY WATER,
Ghuman, B.X., Verma, S.M., and Prihar, S.S.
Punjab Agricultural university, Ludhiana (India). Department of Soils.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 7-10, January-
February 1975. 7 fig, 1 tab, 6 ref.
Descriptors: *Leaching, *Salts, *Soil moisture, *Infiltration, *Path of pollu-
tants, Groundwater, Water pollution, Chlorides, Soil water movement, Percolation,
Distribution patterns, Water distribution(Applied).
Certain concepts regarding the displacement and profile-spread of surface-salts
with applied water and the leaching efficiency of applied water were experimen-
tally verified with soil columns. Treatments included different amounts and rates
of water application and different initial soil water contents. Salt and water
profiles were determined by destructive sampling in 2-cm depth intervals after
variable times of redistribution. Salt front coincided with the water front in
the initially dry soil and lagged behind it in the initially moist soil. Salt
peak immediately after infiltration and after redistribution, for all initial
soil water contents, occurred at a depth above which total water storage equaled
infiltration. But the salt spread in the profile increased as the initial water
content increased. Immediately following infiltration, salt was displaced deeper
with slower than with faster rates of water application. But when the applica-
tion plus redistribution time was matched, the salt showed deeper movement with
water added at faster than at slower rates. These results show that slower rates
of water application may not increase the leaching efficiency of water under
field conditions.
75:02G-016
DETERMINATION OF SOIL WATER DIFFUSIVITY BY SORPTIVITY MEASUREMENTS,
Dirksen, C.
Agricultural Research Service, Riverside, California Salinity Lab.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 22-27, January-
February 1975. 6 fig, 2 tab, 11 ref.
Descriptors: *Soil moisture, *Moisture content, *Diffusion, *Absorption, *Hy-
draulic conductivity, Soil physical properties, Unsaturated flow, Soil water
movement, Sorption, Numerical analysis, Soil water, Diffusivity.
A new method was proposed for determining the dependence of soil water diffusivity
and conductivity on water content or pressure head in the tensiometer range.
A weighted mean diffusivity is used to linearize the one-dimensional absorption
problem. The resulting cumulative absorption is equated to that of the exact
nonlinear solution to obtain an expression for the diffusivity in terms of sorp-
tivity. To use this result, sorptivities must be measured for a series of step-
function increases in the water content (pressure head) at the absorption inter-
face. Such sorptivity measurements are quickly and easily made in situ. The
method was tested on a numerical example with nearly perfect results. Also,
sorptivity measurements were made on laboratory soil columns and the derived
hydraulic conductibities compared well with those measured directly under steady
state conditions.
75:02G-017
INFLUENCE OF SOIL MICROSTRUCTURE ON WATER CHARACTERISTICS OF SELECTED HAWAIIAN
SOILS,
Tsuji, G.Y., Watanabe, R.T., and Sakai, W.S.
Hawaii Agricultural Experiment Station, Honolulu.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 28-33, January-
February 1975. 7 fig, 2 tab, 12 ref.
Descriptors: *Soil structure, *Soil physical properties, *Soil water, *Electronic
equipment, Temperature, Retention, Soil texture, *Hawaii, Bulk density, Anisotropy,
33
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Montmorillonite, Kaolinite.
The higher water-holding capacity of Oxisols and Ultisols compared to that of the
Vertisols and Inceptisols at 15 bars of suction was attributed to the presence
of intraaggregate void spaces. Existence of such voids was verified with the
aid of a scanning electron microscope. These voids were obvious in soils with
kaolinitic and oxidic mineralogy but were not evident in soils of montmorilloni-
tic or amorphous oxide composition.
75:020-018
EFFECT OF STONES ON THE HYDRAULIC CONDUCTIVITY OF RELATIVELY DRY DESERT SOILS,
Mehuys, G.R., Stolzy, L.H., and Weeks, L.V.
California University, Riverside. Department of Soil Science and Agricultural
Engineering.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 37-42, January-
February 1975. 8 fig, 4 tab, 13 ref.
Descriptors: *Soil water, *Soil water movement, *Bulk density, *Hydraulic con-
ductivity, Laboratory tests, Tensiometers, Volumetric analysis, Gravimetric anal-
ysis, Deserts, Soils.
The objective was to determine whether moisture transmission properties of stony
soils could be evaluated using samples of the same soil in which the stony
fraction (greater than 2 mm) had been excluded. Experiments were conducted in
the laboratory on soil columns with and without stones. Unsaturated hydraulic
conductivity was measured with a transient outflow method over the matric poten-
tial range of -0.05 to -50 bars by using tensiometers and soil psychrometers. On
a weight basis, the soils studied contained up to 40% stones greater than 2 mm
in diameter. If expressed as a function of matric potential, hydraulic conduc-
tivity values were similar, with or without stones. Soil water potential as
measured by tensiometers or by thermocouple psychrometers was not affected by
stones because these instruments respond to moisture changes in the soil portion
only. When unsaturated hydraulic conductivity was expressed as a function of
volumetric water content, the apparent conductivities were higher for a given wa-
ter content when stones were present. A simple correction of water contents
of stone-free samples, based on the stone volume of each soil, adequately accoun-
ted for differences observed when water, contents were computed on a., total volume
basis.
75:020-019
LANDFORM-SOIL-VEGETATION-WATER CHEMISTRY RELATIONSHIPS, WRIGLEY AREA, N.W.T.:
II. CHEMICAL, PHYSICAL, AND MINERALOGICAL DETERMINATIONS AND RELATIONSHIPS,
Walmsley, M.E. and Lavkulich, L.M.
British Columbia University, Vancouver. Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 89-93, January-
February 1975. 3 tab, 18 ref.
Descriptors: *Soil-water-plant relationships, *Water chemistry, *Mineralogy,
*Permafrost, *Canada, Geomorphology, Alpine, Grasslands, Colluvium, Bogs, Lakes,
Streams, Soil formation, Clay minerals, Ice, Physical properties.
The relationship among five landforms in terms of chemical, physical, mineralog-
ical, and water chemistry of lakes and the through flowing streams was presented.
The landforms occur as a catenary sequence (toposequence) in the intermittent
permafrost region of the Mackenzie Valley, Northwest Territories, Canada. The
five landforms were identified as an alpine meadow, an area of stone stripe and
stone ring formation, a colluvial slope, an area of coalescing fans, and an
area of polygonal bog formation. Information collected on the chemical quality
of a stream flowing through the area included pH, O2, Ca, Mg, Na, K, Cl, F and
NO3. Chemical, physical, and mineralogical analyses of the soils occurring on
these landforms illustrated the effect of climate on soil genesis. Cryoturbic
action is the dominant process occurring in the stone stripe area while ice
segregation is predominant in the area of polygonal bog formation. The limited
decomposition of the soil organic matter is related to the harsh climate.
34
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Subdued pedogenic development of soils in the coalescing fan area is evident by
their youthful profile differentiation. Water chemistry demonstrated the function-
al and integrated effect between dissolved load in the water and the landform
through which the stream has flown.
75:020-020
A NEW CERAMIC CUP SOIL-WATER SAMPLER,
Harris, A.R., and Hansen, E.A.
Forest Service (USDA), La Crosse, Wisconsin, Watershed Lab.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 157-158, January-
February 1975. 1 fig, 5 ref. *
Descriptors: *Soil water, *Water sampling, *Instrumentation, .Sampling, Water
pollution.
A newly designed soil-water sampler utilizing a miniature porous ceramic cup was
suitable for either collecting large samples or for microtechniques. It elimina-
ted sample transfer in the field and contamination from water channeling along
sampler, and can be enclosed to discourage vandalism. It also permitted immediate
preservation of the collected sample.
75:020-021
FIELD DETERMINATION OF HYSTERESIS IN SOIL-WATER CHARACTERISTICS,
Royer, J.M., and Vachaud, G.
Universite Scientifique et Medicale de Grenoble (France). Institut de Mecanique.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 221-223, March-
April 1975. 3 fig, 12 ref.
Descriptors: *Soil water, *Hysteresis, On-site investigations, *Soil moisture,
*Soil physical properties, Soils, Soil tests, Soil investigations. Moisture,
Moisture content, Moisture availability, Soil moisture meters, Instrumentation,
Soil density, Water pressure.
It is still a common practice to infer field values of soil water content (or of
soil water suction) from the measurement of the soil water suction (or the
soil water content) and the use of "representative" soil water characteristics.
A series of independent measurements of changes in water content and in soil
suction were conducted on two watersheds during one year. It was shown on both
sites that hysteresis is too important to be neglected, and that considerable
errors will result from the determination of both water content and soil suction
with the use of a single sensor.
75:02G-022
FINITE ELEMENT ANALYSIS OF TWO-DIMENSIONAL FLOW IN SOILS CONSIDERING WATER
UPTAKE BY ROOTS: I. THEORY,
Neuman, S.P-, Feddes, R.A., and Bresler, E.
Agricultural Research Organization, Bet-Dagan (Israel). Inst. of Soils and Water.
Soil Science Society of American Proceedings, Vol. 39, No. 2, p 224-230, March-
April 1975. 3 fig, 1 tab, 8 ref, 1 append.
Descriptors: *Finite element analysis, *Soil water movement, *Unsaturated flow,
*Soil-water-plant relationships, *Root systems, Absorption, Numerical analysis,
Mathematical models, Soil moisture, Porous media, Hydraulic conductivity, Flow,
Air-earth interfaces, Boundaries(Surfaces), Seepage, Infiltration, Anisotropy,
Equations, Evaporation.
The problem of two-dimensional nonsteady flow of water in unsaturated and partly
saturates porous media was solved by a Galerkin-type finite element approach.
Particular emphasis was placed on the simulation of atmospheric boundaries and
on water uptake by plant roots. The finite element method was shown to have
several advantages over conventional finite difference techniques. It can easily
handle nonuniform flow regions having irregular boundaries and arbitrary degrees
35
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of local anisotropy. Nonlinear atmospheric boundary conditions along evaporation
or infiltration surfaces and along seepage faces were handled by a unique proce-
dure. This iterative procedure relies on the ease with which flux normal or
any boundary of the flow region is assigned in the finite element approach.
Experience with this method indicates that rapid rates of convergence can be a-
chieved in many cases.
75:020-023
FINITE ELEMENT ANALYSIS OF TWO-DIMENSIONAL FLOW IN SOILS CONSIDERING WATER UPTAKE
BY ROOTS: II. FIELD APPLICATIONS,
Feddes, R.A., Neuman, S.P., and Bresler, E.
Institute for Land and Water Management Research, Wageningen (Netherlands).
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 231-237, March-
April 1975. 12 fig, 6 ref.
Descriptors: *0n-site tests, *field crops, *Mathematical models, *Finite element
analysis, *Soil water movement, Unsaturated flow, Soil-water-plant relationships,
Root systems, Anisotropy, Absorption, Numerical analysis, Soil moisture, Hydraulic
conductivity, Evapotranspiration, Ditches, Water table, Soil properties, Hydraulic
gradient, Infiltration, Simulation analysis.
Part I described a Galerkin-type finite element approach to the simulation of
two-dimensional transient flow in saturated-unsaturated soils considering evapo-
ration and water uptake by roots. The purpose of Part II was to verify the numer-
ical model against field measurements, to compare the results with those obtained
by a finite difference technique, and to show how the finite element method can
be applied to complex but realistic two-dimensional flow situations. Two examples
were given. The first concerns one-dimensional flow and it compares numerical
results with those obtained experimentally in the field from water balance studies
on red cabbage (Brassica oleracea L. 'Rode Herfst') grown on a clay soil in the
presence of a water table. The second example describes two-dimensional flow in
a complex field situation in The Netherlands where flow takes place under cropped
field conditions through five anisotropic layers. Water is supplied to the system
by infiltration from two unlined ditches and is withdrawn from the system by
evapotranspiration and by leakage to an underlying pumped aquifer.
75:02G-024
EVALUATING SURFACE-SOIL WATER CONTENT BY MEASURING REFLECTANCE,
Skidmore, E.L., Dickerson, J.D., and Schimmelpfennig, H.
Agricultural Research Service, Manhattan, Kansas.
Soil Science Society of American Proceedings, Vol 39, No. 2, p 238-242, March-
April 1975. 7 fig, 1 tab, 24 ref.
Descriptors: *Soil moisture meters, *Soil moisture, *Instrumentation, Soil
water, Soil surfaces, Reflectance, Soil erosion, Infrared radiation. Soils, Soil
properties.
Water's property to absorb certain wavelengths in the near infrared was the basis
for developing a reflectometer to measure reflectance of near-in-frared radiation
from a soil surface. The reflectometer's essential elements include: source
of infrared radiation, optical system, integrating sphere, detector, light chopper,
amplifier, and meter system. The radiation from an incandescent lamp was filtered
with a narrow-band pass filter, chopped, and allowed to strike the test surface
where it was either absorbed or reflected onto the surface of the integrating
sphere. The intensity of the reflected radiation was measured with a lead sulfide
detector and appropriate amplifer and meter. The reflectance as a function of
water content was measured for filter paper and several soils at 1.30, 1.45, 1.65,
and 1.95 micrometers. Although at low water contents soil properties (other
than water content) strongly influenced soil reflectance, at 1.95-micrometer
wavelength—the most prominent absorption band of liquid water—the reflectance-
content relationship tended to be log-linear.
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75:02G-025
SOIL WATER HYSTERESIS IN A FIELD SOIL,
Watson, K.K., Reginato, R.J., and Jackson, R.D.
Agricultural Research Service, Phoenix, Arizona. Water Conservation Lab.
Soil science Society of America Proceedings, Vol. 39, No. 2, p 2420246, March-
April 1975. 5 fig, 11 ref.
Descriptors: *Soil water, "Hysteresis, On-site investigation, *Soil moisture,
*Soil physical properties, Soil, Soil tests, Soil investigations, Moisture,
Moisture content, Moisture availability, Soil moisture meters, Instrumentation,
Soil density, Water pressure, Tensiometers, Bulk density.
The requirements for the measurement in the field of the hysteresis characteris-
tics of the soil water pressure (h)-water content (theta) relationship were dis-
cussed and details given of the method whereby an undisturbed hexagonal monolith
of soil was isolated from the surrounding soil. The instrumentation used in
measuring the soil water movement in this monolith, with particular reference to
h and theta measurements at points in the soil profile, was described. The
shapes of typical theta-time and h-time curves were discussed in relation to pos-
sible hysteresis, and the actual h(theta) relationship for soil at the 8-to 9-cm
depth was determined. <
75:02G-026
DRAINAGE CHARACTERISTICS OF SOILS,
Corey, A.T., and Brooks, R.H.
Colorado State University, Fort Collins. Department of Agricultural Engineering.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 251-255, March-
April 1975. 5 fig, 12, ref.
Descriptors: *Soil moisture, *Soil water movement, *Conductivity, *Pore pressure,
Drainage effects, Percolation, Moisture tension, Moisture content, Negative
pore pressure, *Drainage.
Evidence was obtained indicating that neither water conductivity nor water content
are single-valued functions of soil water suction during a period in which soil
is draining continuously. Functional relationships between water conductivity
and soil water suction measured during continuous drainage were found to be dif-
ferent from those frequently observed during steady-state experiments. During
drainage, a finite suction is recorded before a soil begins to desaturate and this
suction is often larger than the suction existing immediately^.after drainage
starts. It was postulated that the reduction in suction is a result of air reach-
ing larger (previously isolated) pores.
75:02G-027
PREDICTION OF INFILTRATION OF WATER INTO AGGREGATED CLAY SOIL SAMPLES,
Gumbs, F.A., and Warkentin, B.P-
Macdonald Coll., Ste. Anne de Bellevue (Quebec). Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 255-263, March-
April 1975. 12 fig, 4 tab, 20 ref.
Descriptors: *Soil properties, *Infiltration, *Aggregates, Model studies, Labor-
atory tests, Hysteresis, Conductivity, Diffusivity, Soil pressure, Retention,
Wetting, Drying, Moisture content, Percolation, Gravity, Tensiometers, Bulk densi-
ty, Stability, Sampling.
Physical properties—stability, water retention, diffusivity, and conductivity—
relevant to the study of infiltration into aggregated media were measured for
four aggregate sizes. These media were considered stable to infiltration. The
hysteresis in moisture retention, equilibrium moisture retention curves, and the
changes in moisture retention with time were measured for confined and uncon-
fined samples of the aggregates. Wetting and drying diffusivities and conductivi-
ties were also measured and used in the prediction of horizontal and vertical
infiltration under zero and small negative pressures into columns of each aggregate
37
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size by using the diffusion equation. Diffusivities and conductivities were
larger on wetting than on drying and generally larger in unconfined than in con-
fined samples. Horizontal and vertical infiltration were reasonably well pre-
dicted when water infiltrated under negative pressure and the diffusivities and
conductivities used were calculated from infiltration profiles developed under
the same water tension. For these media, the values of water tension, diffusivity,
and conductivity at any water content depend on the rate of wetting. The values
to be used in the prediction of infiltration must therefore be measured for times
of wetting which correspond to the duration of infiltration. The classical dif-
fusion equation can be used to predict infiltration into aggregated clay soils
if the correct diffusivities and conductivities are used.
75:02G-028
TWO-DIMENSIONAL SIMILARITY SOLUTION: THEORY AND APPLICATION TO THE DETERMINATION
OF SOIL-WATER DIFFUSIVITY,
Turner, N.C., and Parlange, J-Y
Connecticut Agricultural Experimental Station, New Haven. Department of Ecology
and Climatology.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 387-390, May-
June 1975. 3 fig, 1 tab, 5 ref.
Descriptors: *Soil water, *Infiltration, *Infiltration rates. Diffusion, Mois-
ture content, Sands.
A similarity solution exists in two-dimension when a constant flux is imposed
along a line source. Following the Bruce and Klute method in one-dimension,
this similarity solution can be used to determine the soil water diffusivity. The
application of the method was illustrated for a sandy loam. The advantage of the
method is that the slope of the moisture profile is finite and easily measured,
even close to the source.
75:02G-029
SOIL WATER MEASUREMENT WITH AN INEXPENSIVE SPECTROPHOTOMETER,
Bowers, S.A., Smith, S.J., Fisher, H.D., and Miller, G.E.
Agricultural Research Service. Durant, Oklahoma. Water Quality Management.
Soil Science Society of America Proceeding, Vol. 39, No. 3, P 391-393, May-June
1975. 4 fig, 1 tab, 3 ref.
Descriptors: *Soil water, *Water measurement, *lnstrumentation, *Soil moisture
meters, 'Spectrometers, On-site tests, Analytical techniques, Electronic equipment,
Moisture, Moisture content, Evaluation, Available water, Soil moisture, Soil
properties, Moisture availability, Spectrophotometry, Clay loam, Silts, Clays,
Sands, Absorption.
A small, portable, battery-powered, spectrophotometer was developed to measure
soil water content rapidly. Soil water contents of 16 soils were related to the
absorbance at 1.94 micrometers by a soil-methanol extract by the curvilinear
equation: Absorbance = K(% soil water/100 + 1.025(% soil water)) + a. With the
exception of Houston Black Clay, one equation could be used for all soils. De-
termination time for individual samples was approximately 15 min.
75:020-030
ON SOLVING THE FLOW EQUATION IN UNSATURATED SOILS BY OPTIMIZATION: HORIZONTAL
INFILTRATION,
Parlange, J-Y
Connecticut Agricultural Experiment Station, New Haven. Department of Ecology and
Climatology.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 416-418, May-June
1975. 1 tab, 11 ref. 1 append.
Descriptors: *Unsaturated flow, *Absorption, *Diffusivity, Soils, Soil water,
Soil physics, Soil mechanics, Infiltration, Mathematics, Mathematical studies.
38
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Optimization, Subsurface waters, Soil moisture, Flow, Diffusion, Soil water move-
ment, Agriculture, Agronomy, Clays, Labor.
Recently, integral methods have been developed that provide accurate approximations
to the diffusion equation with rapidly varying diffusivity, but require in general
some numerical iteration. A new analytical approach was developed which yields
optimal approximation without any numerical iteration. The method was applied
to the problem of one-dimensional horizontal infiltration of water in soils. It
was shown that the sorptivity is an invariant, which can be expressed in terms of
the sum of two integrals involving the diffusivity. The analytical results were
in excellent agreement with numerical calculations for Yolo light clay. Since
diffusivity for most soils varies even more rapidly than for Yolo light clay, the
approach should prove even more accurate for most soils. The technique is quite
general and can be adapted to solve other problems of water movement in unsatura-
ted soils.
75:02G-031
A ONE-STEP WETTING PROCEDURE FOR DETERMINING BOTH WATER CHARACTERISTIC AND HYDRAU-
LIC CONDUCTIVITY OF A SOIL CORE,
Ahuja, L.R.
Hawaii University, Honolulu. Department of Agronomy and Soil Science.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 418-423, May-June
1975. 9 fig, 8 ref.
Descriptors: *Hydraulic conductivity, *Soil water movement, *Unsaturated flow,
Soil mechanics, Soil physics, Soil physical properties, Numerical analysis,
Laboratory tests, Diffusivity, Soils, Soil water, Soil properties, Soil moisture,
Agriculture, Agronomy, Wetting.
Reasonable simplifications were used to obtain both the suction-water content and
unsaturated hydraulic conductivity relationships from data measured during wetting
of a relatively dry soil core through a high-hydraulic-resistance porous plate.
For soil-water contents below the bubbling-pressure value, the two functions
were assumed to be of previously known power forms. The resulting similarity
was then utilized to obtain these functions from cumulative inflow and wetting-
front position data, using an iterative numerical solution of the ordinary differ-
ential equations. Accuracy of the solution was tested on a set of generated
data. Tests of the technique as a whole on generated data for one soil and exper-
imental data for another showed it to be promising. For water contents above the
bubbling-pressure value, a method was suggested to obtain the two hydraulic
properties from cumulative inflow and soil-water suction at the other end of the
core.
75:02G-032
MATHEMATICAL ANALYSIS OF STEADY SATURATED FLOW THROUGH A MULTILAYERED SOIL WITH
A SLOPING SURFACE,
Selim, H.M., Selim, M.S., and Kirkham, D.
Florida University, Gainesville. Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 445-453, May-June
1975. 12 fig, 3 tab, 16 ref.
Descriptors: *Saturated flow, *Seepage, *Slopes, *Infiltration. Potential flow,
Saturated soils, Soil water movement, Mathematical studies, Mathematical models,
Model studies, Hydraulic conductivity, Permeability, Soil water, Groundwater
movement,Groundwater potential, Flow, Soils.
An analytical solution was presented for a two-dimensional multilayered hillside
seepage problem. The soil was horizontally stratified with each layer having a
different permeability. The flow medium was assumed to be water-saturated to
the soil surface, bounded below by an impermeable barrier at a finite depth, and
bounded laterally by vertical streamlines. Seepage occurred into the flow medium
along the upper part and out along the lower part of the sloping soil surface.
Two situations were analyzed, one with a constant slope soil surface and another
39
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with an arbitrarily shaped soil surface. The potential and stream functions ^
the problem were developed by starting with a general series solution to Laplace s
equation and using a modified Gram-Schmidt method to determine the series coeffi-
cients. Solutions were derived for two-layered and three-layered soils. From
these derivations, solutions for soils with more than three layers could be
readily deduced. The results presented include flow nets, seepage velocities, and
infiltration rates for two-layered and three-layered soils.
75:020-033
A COMPARISON OF THE GREEN - AMPT AND PHILIP TWO-TERM INFILTRATION,
Fok, Y-S.
Hawaii University, Honolulu, Civil Engineering Department.
Transactions of the American Society of Agricultural Engineers, Vol. 18 No. 6,
p 1073-1075, November-December 1975. 1 tab 12 ref.
Descriptors: *Infiltration, *Mathematical studies, Equations, Soil water move-
ment.
For the benefit of the users of both the Green - AMPT and Philip two-term equa-
tions, it is shown in this paper that the Philip two-term equation can be derived
from the Green - AMPT equation and differences between these two equations are
evaluated.
75:02G-034
TOTAL NITROGEN USING A SODIUM HYDROXIDE INDEX AND DOUBLE SAMPLING THEORY,
Geist, J.M., Hazard, J.W.
Pacific Northwest Forest and Range Experiment Station, La Grande, Oregon 97850.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 340-343, March-
April 1975. 1 fig, 1 tab, 8 equ, 4 ref.
Descriptors: *Nitrogen, *Regression analysis, Soil chemistry, Soil properties,
Soil investigations, Soil tests.
A regression relationship was investigated between total Kjeldahl soil N and an
NaOh distillable fraction of soil N. The correlation coefficient r was 0.989
for 45 soil samples. A double sampling approach using both analyses to estimate
total N was more efficient than Kjeldahl analyses only. Example applications are
presented under cost and precision limitations. The regression can also be used
to obtain point values of total N for mapping or other nonstatistical purposes.
75:02G-035
SODIUM AVAILABILITY IN NONALKALI SOILS,
Suarez-Hernandez, A., Hanway, J.J.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 308-311, March-
April 1975. 2 fig, 2 tab, 17 ref.
Descriptors: *Sodium, *Soil investigations, *Soil chemistry, *Soil chemical
properties, Soil management, Iowa.
Ryegrass was grown in the greenhouse on undried soil samples from the 0 to 15 and
30 to 45 cm depths of 15 Iowa soils. The NH40Ac exchangeable Na was 21 ppm or
less in all soil samples except those from the 30 to 45 cm depth in southern Iowa
soils, Which contained 28 to 115 ppm exchangeable Na. The pH of these southern
Iowa subsurface samples varied from 5.1 to 6.0. Percentages of Na in the first
harvest of ryegrass were directly related to the exchangeable Na contents of the
soils and inversely related to exchangeable soil K and K content of the plants.
75:02G-036
SPATIAL VARIABILITY IN SOILS BELOW DEPTH OF TILLAGE: BULK DENSITY AND FIFTEEN
ATMOSPHERE PERCENTAGE,
Cassel, O.K., Bauer, A.
North Carolina State University, Raleigh 27607.
Soil Science Society of America, Vol. 39, No. 1, p 247-250, March-April, 1975.
5 fig, 3 tab, 5 ref.
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Descriptors: *Spatial distribution, *Soil investigations, Soil properties
Soil texture, Bulk density, Soil water, Soil pressure.
Soil bulk density (D) and 15-atm percentage (FAP) were measured for three soils—
Haddock sandy loam, Bearden silty clay, both of glacio-lacustrine origin. D and
FAP were measured in approximately 30-cm increments from a depth of 30 to 152 cm.
75:02G-037
REDUCTION OF NITRATE IN A SOIL COLUMN DURING CONTINUOUS FLOW,
Ardakani, M.S., Belser, L.VJ., McLaren, A.D.
California University, Berkeley.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 290-294 March-
April 1975. 5 fig, 2 equ, 21 ref.
A column packed with a homogenous Hanford sandy loam soil was perfused continu-
ously with a solution containing 200 ppm N03(-)~N and 2400 ppm glucose-C. Weekly
estimates of denitrifiers showed that populations increased from 10(2) to > 10(8)/g
of soil. Denitrifiers were most abundant near the surface where NO3(-)-N almost
totally disappeared from the soil solution. An organic matter profile character-
ized by a surface layer developed within 3 weeks. Accumulated organic N accounted
for about 4% of the total applied NO3(-)-N while the remaining 96% disappeared,
presumably by dissimilation, within the top 0.5 cm of the surface layer. Normal-
ized rate constants from 1.2 times 10 (-5) ppm/hour(.)cm3 per organism were
estimated for dissimilation of N03(-)-N from its profiles. In a similar experi-
ment, but without added glucose, less of the NO3(-)-N disappeared from solution;
the percentage decreased from 40 to 15% with time.
75:020-038
DENITRIFICATION RATES IN RELATION TO TOTAL AND EXTRACTABLE SOIL CARBON,
Stanford, G., Vander Pol, R.A., Dzienia, S.
Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 284-289,
March-April 1975. 2 fig, 5 tab, 16 ref.
Descriptors: *Denitrification, *Soil investigations, *Soil chemistry, *Soil
chemical properties, Carbon.
Denitrification rates were studied under near-anaerobic conditions in 30 soils
of diverse origin that differed widely in pH, organic C contents, and other
characteristics. Soils with added N03-N were submerged in water and containers
were sealed to prevent further oxygen intake during incubation. Disappearance
of NO3-N and production of NH4-N were determined at 1-day intervals or longer
over a 10-day period. Since soils were not shaken during incubation, denitrifi-
cation rates were influenced by diffusion of nitrate from the liquid to the soil
layer. In most soils, amounts of NO3-N declined exponentially with time of incu-
bation. Thus, under the experimental conditions, the loss of nitrate was depic-
ted better by log NO3-N vs. time (t, hours) than ppm NO3-N vs. t.
75:02G-039
RETENTION OF ARSENIC BY HYDROXY-ALUMINUM ON SURFACES OF MICACEOUS MINERAL COLLOIDS,
Huang, P.M.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 271-274.
March-April 1975. 2 fig, 5 tab, 19 ref.
Descriptors: *Soil chemistry, *Arsenic compounds, Soil properties. Soil investi-
gations. Soil chemical properties.
This study was carried out to examine the relative significance of As retention
by hydroxy-Al on external and interlamellar surfaces of micaceous mineral colloids.
Depletion of K from muscovite and biotite decreased As retention This effect
was attributed to the exclusion of arsenate ions by the K-depleted layers.
Hydroxy-Al in the interlamellar spaces of vermiculite and K-depleted micas was not
41
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found to contribute significantly to As retention in the solution concentration
range of 2 to 10 ppm As.
75:02G-040
A FIELD STUDY OF SOIL WATER DEPLETION PATTERNS IN PRESENCE OF GROWING SOYBEAN
ROOTS: III. ROOTING CHARACTERISTICS AND ROOT EXTRACTION OF SOIL WATER,
Arya, L.M., Blake, G.R., Farrell, D.A.
Minnesota University, St. Paul, Minnesota.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 437-444, May-
June 1975. 8 fig, 3 tab, 7 equ, 30 ref.
Descriptors: *Soybeans, *Soil water, *Soil water movement, Soil properties,
Soil-water-plant relationships, Root systems, Root development, Root distribution,
Root zone.
Rooting characteristics and water extraction patterns in the root zone of a
mature soybean crop were determined in the field. Rates of water extraction by
the roots in the various 10-cm intervals were computed over an irrigation-drying
cycle, 81 to 91 days after planting. In the 10- to 30- and 60- to 70-cm layers
the extraction rate decreased with time. In the 30- to 60-cm layer an initial
decrease was followed by a substantial increase later in the cycle. Total
extraction between 40 and 240 hours after irrigation decreased with depth—1.32 cm
in the 10- to 20-cm layers and 0.25 cm in the 60- to 70-cm layers. Extraction
rate for the 10- to 70-cm soil during the 47- to 56- and 81- to 91-days growth
periods showed an initially rapid decrease following irrigation but reached
constant levels of 0.48 and 0.39 cm/day, respectively.
75:02G-041
A FIELD STUDY OF SOIL WATER DEPLETION PATTERNS IN PRESENCE OF GROWING SOYBEAN
ROOTS: II. EFFECT OF PLANT GROWTH ON SOIL WATER PRESSURE AND WATER LOSS PATTERNS,
Arya, L.M., Blake, G.R., Farrell, D.A.
Minnesota University, St. Paul, Minnesota.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 430-436, May-
June 1975. 9 fig, 1 tab, 15 ref.
Descriptors: *Soybeans, *Soil water, *Soil water movement, Soil properties,
Soil-water-plant relationships, Root systems, Plant growth, Root zone.
Soil-water pressure and water-loss patterns in the root zone of soybean were
determined from daily observations during irrigation-drying cycles for four
growth periods after planting. Tensiometric measurements of soil water pressure
were made on a 10-cm square grid from one plant row to an adjacent one spaced
80 cm apart, and between 10- and 70-cm depths. Water contents were inferred
from pressure-water content relationships.
75:02G-042
A FIELD STUDY OF SOIL WATER DEPLETION PATTERNS IN PRESENCE OF GROWING SOYBEAN
ROOTS: I. DETERMINATION OF HYDRAULIC PROPERTIES OF THE SOIL,
Arya, L.M., Farrell, D.A., Blake, G.R.
Minnesota University, St. Paul, Minnesota.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 424-429, May-
June 1975. 8 fig, 3 tab, 6 ref.
Descriptors: *Soybeans, *Soil water, *Soil physical properties, Soil properties,
Soil water movement, Soil-water-plant relationships, Root systems, Hydraulic
conductivity, Root zone.
The hydraulic properties of a Waukegan loam profile were determined by field and
laboratory procedures. Pressure-water content relationships obtained in the
laboratory were found to be variable at pressures above -100 cm of water. In
this range field data were considered more reliable. Hydraulic conductivity in
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the field was determined from flux and hydraulic-head gradient data. Hydraulic-
head gradients were obtained from tensiometric measurements of pressure at various
depths. In the soil profile that was subject to both evaporation and drainage,
the position of a downward moving "zero flux" boundary was determined Flux
across any depth was obtained by integrating the rate of change of water content
with time between the "zero flux" boundary and the depth in question.
75:02G-043
A NEW TECHNIQUE FOR RAPID AND CONTINUOUS MEASUREMENT OF REDOX POTENTIALS,
Linebarger, R.S., Whisler, F.D., Lance, J.C.
Lockheed, Missiles and Space Co., Sunnyvale, CA
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 375-377, March-
April, 1975. 2 fig, 2 ref.
Descriptors: *Laboratory tests, *Electrodes, Soil tests, Sewage, Sewage disposal.
A new "salt bridge" technique for the rapid and continuous measurement of redox
potentials at various depths in multiple soil columns, utilizing only one calomel
electrode, is described. The method was compared with a previous technique where
a reference electrode was placed in each of 8 soil columns, containing a total
of 42 platinum redox probes. A least-squares best fit statistical analysis indi-
cated that the new technique yields redox potential measurements as accurate
as those of the previous method. Several other features of the salt bridge
technique make it advantageous for use both in the laboratory and in the field.
75:02G-044
USE OF AMMONIA ELECTRODE FOR DETERMINATION OF CATION EXCHANGE CAPACITY IN SOIL
STUDIES,
Miller, G.A., Riecken, F.F., Walter, N.F.
Iowa State University, Ames, Iowa.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 372-373, March-
April 1975. 1 fig, 7 ref.
Descriptors: *Cation exchange, Soil tests, Soil properties, Soil investigations,
Laboratory tests, Electrodes.
Cation exchange capacity (CEC) was determined with an ammonia electrode on 37
horizon samples from four soil profiles. .The profiles selected to test this
procedure had a wide range of physical and chemical properties. The procedure
was a modification of other techniques. Centrifugation was employed for removal
of exchangeable cations and ammonium salts. The CEC values obtained with the
ammonia electrode agreed closely with values obtained by direct distillation for
adsorbed ammonia. The method was simple and rapid and suitable for soil studies.
Using the proposed method a single operator could carry out the analysis of 16
or more samples in a normal working day.
75:02G-045
THE USE OF A DEPENDENT DOMAIN MODEL OF HYSTERESIS IN NUMERICAL SOIL WATER
STUDIES,
Lees, S.J., Watson, K.K.
New Southe Wales University, Kensington (Australia). School of Engineering.
Water Resources Research, Vol. 11, No. 6, p 943-948. December 1975. 4 fig, 19
ref.
Descriptors: *Soil water movement, *Hysteresis, *Unsaturated flow, *Model
studies, Numerical analysis, Soil water, Soil pressure, Soil moisture, Moisture
content, Infiltration, Moisture tension, Subsurface waters, Recharge, Drainage
effects, Mathematical models, Gravitational water.
The analysis of intermittent soil water systems requires the inclusion of a cap-
illary hysteresis model in the space-time simulation of the flow process. Domain
models of hysteresis were reviewed, and the approach of Poulovassilis and Childs
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(1971) was selected as the basis for a numerical hysteresis program which enabled
the generation of primary, secondary, and higher order scanning curves. The
dependence of the pore draining pressure on the pressure at the previous reversal
was restricted to reversals from the boundary curves. This enabled the distri-
bution function to be approximated by a series of regularly spaced, independent
domain-type distribution diagrams, each being derived from an experimental pri-
mary curve and a set of estimated secondary scanning curves. The effectiveness
of the approach was demonstrated by simulating the movement of water in a profile
of experimental sand subject to intermittent infiltration-redistribution sequences.
In particular, the hysteretic path followed by the surface node was used to
illustrate the generation of the necessary higher order scanning curves.
75:02G-046
PREDICTING ANION MOVEMENT IN DISTURBED AND UNDISTURBED SOILS,
Cassel, O.K., Van Genuchten, M.T., Wierenga, P.J.
Northe Carolina State University, Raleigh. Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1015-1019,
November-December 1975. 6 fig, 22 ref.
Descriptors: *Anions, *Ion transport, *Soils, Cores, Laboratory tests, Tracers,
Chlorine radioisotopes, Nitrates, Numerical analysis, Mathematical models,
Equations, Convection, Diffusion, Nitrification, Soil water, Pore water, Velocity,
Depth, Soil texture, Bulk density, Solutes, Loam, *Forecasting.
Prediction of anion displacement in soils has proven difficult owing to anion
exclusion and the occurrence of anion sources or sinks within the soil system.
In addition, variations in bulk density and texture with depth cause mean pore
water velocity and soil water content to be functions of depth. A numerical so-
lution of a modified convective diffusion equation, which accounts for apparent
anion exclusion and variations in soil water content and mean pore water velocity
as functions of depth, was discussed. Moreover, a zero-order rate term was in-
corporated to account for nitrification occurring in the upper portion of the soil
profile. The model was tested using previously published NO3 and C136 displace-
ment data for disturbed and undisturbed cores of Aberdeen loam. The model pre-
dicted C136 displacement well. Incorporation of the source term improved predic-
tion of the nitrate breakthrough curve, but agreement of the predicted curve with
observed data was only fair. When average values for water content and bulk
density were used throughout the entire column, instead of depth dependent values,
the description of anion displacement may be less than the variation in solute
movement observed among replicate soil cores.
75:02G-047
WATER FLUX AND ELECTRICAL POTENTIALS IN WATER-SATURATED BENTONITE,
Gairon, S., Swartzendruber, D.
Purdue University, Lafayette, Indiana. Agricultural Experiment Station.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 811-817, September-
October 1975. 6 fig, 1 tab, 8 ref.
Descriptors: *Zeta potential. Flow, *Hydraulic gradient, *Bentonite, Saturated
flow, Clays, Seepage, Permeameters, Hydraulic properties, Hydraulic conductivity,
Equipment, Laboratory tests, Hysteresis, Expansive clays.
Electrical potential, water flux, and hydraulic gradient were studied for satu-
rated water flow through plugs of sodium bentonite at concentrations ranging
from 11.5 to 35.1% clay. A special permeameter with an adjustable piston allowed
measurements to be taken with a given mass of clay, but with successively lower
clay concentrations. At the lowest clay content, both electrical potential and
water flux increased less than proportionally with increasing hydraulic gradient.
This less-than-proportional behavior decreased as clay concentration increased,
and, at 28.4% clay, proportional response to hydraulic gradient was obtained
for both electrical potential and water flux. A less-than-proportional relation-
ship between electrical potential and hydraulic gradient did not cause the water
44
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flux to increase more than proportionally with increasing hydraulic gradient
in contrast with what has been reported for nonswelling quartz powder and would
be inferred from the classical double-layer theory of streaming potential and
electroosmotic flow. The only indication of a more-than-proportional flux-gradient
relationship was found for a 35.1% clay concentration, in the form of a linear
relationship displaced to the right from the origin to yield a positive gradient
intercept and a negative water flux at zero hydraulic gradient.
75:02G-048
A DEPENDENT DOMAIN MODEL OF CAPILLARY HYSTERESIS,
Mualem, Y., Dagan, G.
Technion-Israel Institute of Technology, Haifa. Faculty of Civil Engineering.
Water Resources Research, Vol. 11, No. 3, p 452-460, June 1975. 15 fig, 7 ref,
2 append.
Descriptors: *Hysteresis, *Capillary water, *Capillary fringe, *Mathematical
models, Model studies, Wetting, Drying, Soil moisture, Soil water, Hygroscopic
water, Pores.
A model of capillary hysteresis which takes into account the phenomenon of block-
age against air (and water) entry was presented. The model was based on our
previous (1974) model II, which predicts any hysteretic path with the aid of two
functions, L(Psi). The model was generalized by adding a new function of pore
blockage against air (and a function of pore blockage against water) , as has been
suggested by D. H. Everett (1967) and G.C. Topp (1971) . It was found that the
function of pore blockage against water is of a lesser significance and can be
neglected in most cases. A technique of deriving L()si), H(Psi), and the function
of pore blockage against water from the measured boundary loop and one primary
drying scanning curve was presented. A simple method of predicting any hysteretic
path was suggested. It was found that the generalized model leads to better
results than the models based on independent domain theories for soils having a
major portion of their hysteretic loop in the range of air entry value.
75:02G-049
FACTORS INFLUENCING INFILTRATION AND SEDIMENT PRODUCTION OF SEMIARID RANGELANDS
IN NEVADA,
Blackburn, W.H.
Texas A and M University, College Station. Department of Range Science.
Water Resources Research, Vol. 11, No. 6, p 929-937, December 1975. 3 fig,
6 tab, 27 ref.
Descriptors: *Infiltration, *Erosion, *Sediment yield, *Watersheds(Basins) ,
*Plant morphology, *Nevada, Soil structure, Antecedent moisture content, Simula-
ted rainfall, Field capacity, Silts, Arid lands, Semiarid climates.
Simulated rainfall was used to study infiltration rates and sediment production
of 28 plant communities and soils of five watershed areas in central and eastern
Nevada. Two antecedent soil moisture conditions were used: soil initially air
dry and initially at field capacity. Infiltration rates and sediment production
of the various soils are largely controlled by extent and surface morphology of
dune interspace soils. Pertinent factors are the depth of surface horizon,
percent of carbon, pH, bulk density, and percent silt in the dunes. Vesicular
horizons are unstable in dune interspace surface soils. These horizons seldom
occur in coppice dunes or in well-aggregated dune interspace soils. Infiltration
rate is negatively related, and sediment production positively related to the
occurrence and morphology of vesicular horizons. More sediment is produced from
soils with antecedent moisture initially at field capacity than from initially
dry soil because of the instability of vesicular horizons when the soils were
saturated.
75:02G-050
THE GROWTH OF DISTURBANCES IN UNSTABLE INFILTRATION FLOWS,
45
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Philip, J.R. .
Commonwealth Scientific and Industrial Research Organization, Canberra (Australia),
Division of Environmental Mechanics.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1049-1053,
November-December 1975. 3 fig, 3 ref.
Descriptors: *Soil water movement, *Unsaturated flow, *Mathematical models, *Lab-
oratory tests, *Infiltration, Hydrodynamics, Heterogeneity, Moisture content,
Wetting, Depth, Pressure head, Atmospheric pressure, Velocity, Equations, Hydrau-
lic conductivity.
The stability analysis of the delta-function model of infiltration yields a max-
imum wave-number for unstable disturbances, Merit, and a wave-number for maximum
amplification, M*. The 'column effect,1 i.e. the suppression of instability in
laboratory columns, depends on Merit? and the dimensions of fingers in unstable
flows can be expected to depend on M*. When instability is induced by a sudden
jump of G, the water pressure gradient behind the wetting front, Merit and M*
may be evaluated simply and directly. When, on the other hand, instability emer-
ges during gradual increase of G, it is necessary to study the amplification of
disturbances during the whole course of increase of G through positive values.
Such a study was made for one example of instability induced by air compression
and for one where it was induced by increase of conductivity with depth. Both
exhibited qualitatively similar patterns of amplification: disturbances of small
M (wave-number) begin to be amplified sooner, but ultimately overtaken by some
disturbances of larger M starting later. Definite values of M* were found, and
the results discussed with special reference to fingering and to the column effect.
75:02G-051
WATER RETENTION BY CORE AND SIEVED SOIL SAMPLES,
Unger, P.W.
Agricultural Research Service, Bushland, Texas.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1197-1200,
November-December 1975. 2 fig, 2 tab, 13 ref.
Descriptors: *Soil water *Soil moisture, Moisture availability, Moisture content,
Retention, Soil properties, Soil texture, Soil management, Water storage, Storage
capacity, Cultivation, Sampling.
Mechanical analyses and water retention by core and sieved soil at -1/3 and -15
bar matric potentials were determined for samples from 26 sites ranging in texture
from sand to clay. Objectives were to obtain a basis for identifying which soils
may be influenced by deep tillage and profile modification with respect to water
storage capacity and to determine the magnitude of errors possible when using
sieved soils to establish field soil water contents. At -1/3 bar potential,
cores retained more water than sieved soil when the water content was below 11%.
The opposite occurred at higher water contents. At -15 bars potential, cores con-
tained about 1 percentage point more water than sieved soils throughout the water
content range encountered. These results showed that .treatments which thoroughly
disrupt the natural soil structure may decrease and increase the storage capacity
of coarse- and fine-textured soils, respectively. When expressed as a percent
of the core water content, differences between core and sieved soil contents at
-1/3 bar potential ranged from -40 to +25% at 5 and 70% core water contents,
respectively. At -15 bars potential, the range was from -52 to -4% at 5 and 25%
core water contents, respectively. These differences indicate caution should be
used when using sieved soils to infer water retention by field soils, regardless
of texture.
75:02G-052 !
IN SITU HYDRAULIC CONDUCTIVITY AT FOUR HILLSLOPE LOCATIONS IN A CLOSED DRAINAGE
SYSTEM,
Matzdorf, K.D., Cassel, O.K., Worcester, B.K., Malo, D.D.
North Dakota State University, Fargo. Department of Soils.
Soil Science of America Proceedings, Vol. 39, No. 3, p 508-512, May-June 1975.
6 fig, 2 tab, 12 ref.
46
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Descriptors: "Hydraulic conductivity, "infiltration, *Glacial soils, *North
Dakota, Till, Slopes, On-site investigations, Soil water movement, Soil water
Tensiometers, Soil physical properties, Irrigation, Groundwater movement, Unsatu-
rated flow, Moisture content, Agronomy.
Virtually no information has been published concerning the hydraulic properties
of large acreage of till plain soils associated with 'potholes' in northcentral
United States and Canada. Objectives of research were to measure and compare in
situ hydraulic conductivities and selected soil physical properties at several
depths in four soil profiles on a till plain in southeastern North Dakota
Theoretical hydraulic conductivity values were calculated and compared with the
in situ conductivities. Unsaturated soil hydraulic conductivity vs. depth was
measured in situ at four sites on a toposeguence developed from a glacial till.
Water was allowed to infiltrate the soil at each site and the soil surface covered
to prevent evaporation. During the ensuing drainage periods soil water pressure
was monitored with triplicate tensionmeters at each of six depths. These depths
were selected on the basis of soil morphology. Soil water characteristics, deter-
mined on triplicate 7.6- by 7.6-cm cores taken from the same depth as the tensio-
meters cups, were used in conjunction with soil water pressure data to compute
hydraulic conductivities. Hydraulic conductivity generally increased with depth
to about 90 cm. Below this depth, hydraulic conductivity tended to decrease.
When the matching factor was selected from the midpoint of the measured hydraulic
conductivity range, the conductivities computed by Green and Corey's method com-
pared favorably with those measured in situ.
75:02G-053
IRRIGATION METHOD AS A DETERMINANT OF LARGE PORE PERSISTENCE AND CRUST STRENGTH
OF CULTIVATED SOILS,
Kemper, W.D., Olsen, J.S., Hodgdon, A.
Colorado State University, Fort Collins. Department of Agricultural Engineering.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 519-523, May-June
1975. 6 fig, 1 tab, 6 ref.
Descriptors: *Wetting, *Air entrainment, *Irrigation systems, *Soil surfaces,
*Soil physical properties. Hydraulic conductivity, Infiltration, Permeability,
Interstices, Soil properties. Soil structure. Soil types, Wettability, Aeration,
Saturated soils. Soil gases, Irrigation, Pores, Capillary conductivity, Pore
pressure, Flooding, Soil aggregates. Saturation, Capillary action.
Air dried soils were wetted by flooding, immersion, slow immersion and capillary
action resulting in successively slower rates of wetting. Slow capillary wetting
of a weekly structured soil allowed retention of more large size pore space than
did rapid wetting of a well structured soil. Breaking strength of dried soils
which had been wet by rapid immersion, capillary action, and capillary action
followed by immersion, was much greater for soils wet by rapid immersion. Immer-
sion following slow capillary wetting resulted in soils with intermediate breaking
strengths. A study on corn (Zea mays L.) seedling emergence from a weakly struc-
tured soil showed less than 50% emergence for flooding and up to 100% for capil-
lary wetting.
75:02G-054
EFFECT OF DAILY IRRIGATION ON WATER CONTENT AND SUCTION PROFILES IN SOILS OF
THREE TEXTURES,
Miller, D.E. „ .
Agricultural Research Service, Prosser, Washington. Western Region.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 512-515. May-June
1975, 5 fig, 5 ref.
Descriptors: Irrigation effects, *Soil texture, *Soil water movement, *Soil
types, *Moisture tension, Drainage effects, Evapotranspiration, Irrigation,
Irrigation efficiency, Plant growth, Soil physical properties, Soil properties,
Soil-water-plant relationships, Moisture content, Soil moisture, Soil profiles,
Infiltration, Hydraulic conductivity.
47
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Soil irrigated to replace just evapotranspiration losses produced profiles that
depended upon the flow characteristics of the soil. In Shano silt loam in which
the water moved readily, water distribution was nearly uniform with depth and did
not change time. In soils in which water moved slowly, either because of slow
internal water movement when wet (Ritzville loam) or low unsaturated conductivi-
ties at relatively low suctions (Sagehill sand), the upper soil became wetter-
while the lower soil water decreased by a corresponding amount. With the soil
profile initially wet, several weeks of deficit irrigation passed before surface
soil water content changed markedly.
75:02G-055
TWO-DIMENSIONAL TRANSPORT OF SOLUTES DURING NONSTEADY INFILTRATION FROM A TRICKLE
SOURCE,
Bresler, E.
Volcani Institute of Agricultural Research, Bet Dagan (Israel).
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 604-613, July-
August 1975. 3 fig, 15 ref, 1 append.
Descriptors: *Solutes, *Unsteady flow, *Diffusion, "Convection, "Infiltration,
Mathematical models, Numerical analysis, Equations, Unsaturated flow. Salinity,
Root zone, Darcys law, Soil moisture, Moisture content, Soil water movement, Soils,
Loam, Sands, Evaporation.
A simulation model for analyzing multidimensional simultaneous transfer of a
noninteracting solute and water, applicable to infiltration from a trickle source,
was developed. The equations describing transient two-dimensional transport of
a solute by diffusion and convection in unsaturated porous media were solved
numerically by an approach that eliminated the effect of numerical dispersion.
The noniterative alternating-direction-implicit finite difference procedure was
used. Two mathematical models were considered: (1) a plane flow model involving
the Cartesian coordinates x and z, and (2) an axisymmetric flow model described
by the cylindrical coordinates r and z. An example of transport in a homogeneous,
isotropic and stable sand and loam soil systems was given. Results were shown
for typical cases of trickle infiltration to demonstrate the effects of trickle
discharge and soil-hydraulic properties on the pattern of salt distribution in
the wetted soil zone. The numerical results showed that the approach presented
may be useful in analyzing two-dimensional solute transport processes in soils.
75:02G-056
DESIGN AND USE OF CLOSED-TOP INFILTROMETERS,
Dixon, R.M.
Agricultural Research Service, Tucson, Arizona. Southwest Watershed Research
Center.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 755-763, July-
August 1975. 8 fig, 14 ref.
Descriptors: *Infiltrometers, "Pressure, Surface waters, Pressure head, Infiltra-
tion rates, Porous media, Heterogeneity, Air-earth interfaces, Soils, Data collec-
tions, Design, Border irrigation, Loam, Saturation, Soil management. Watershed
management. Measurement, Soil surfaces, Boundaries(Surfaces).
Several similar closed-top infiltrometers were designed and used to simulated
effective surface heads ranging from minus 3 to plus 1 cm of water. Design was
based on the principle that natural positive soil air pressure may be simulated
by creating an equivalent negative air pressure above ponded surface water.
Effective surface head h sub s, defined as the difference between the ponded water
depth h sub w, and either the actual or simulated soil air pressure head h sub a,
is negative when h sub a is greater than h sub w. Under natural field conditions,
negative h sub s often causes counterflow of soil air during water infiltration.
Narrow ranges in h sub s surrounding zero greatly affect infiltration by control-
ling air and water flow in soil macropores and weakly hydrophilic micropores.
Thirty-minute cumulative infiltration increased 19% per centimeter increase in h
sub s for one soil and 33% per centimeter for another soil. Closed-top infiltro-
meters make possible realistic infiltration measurements under the negative h sub
48
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s commonly produced by rain and irrigation waters as they infiltrate natural soils.
These devices may also be useful in studying the infiltration effects of several
interacting parameters that are related to h sub s, including soil surface macro-
porosity and roughness, macropore space extent and continuity, antecedent soil
air and water, surface wettability and water repellency, wetted surface area and
shape, and surface crust and slope.
75-.02G-057
HYDRAULIC CONDUCTIVITY CALCULATIONS FOR UNSATURATED STEADY-STATE AND TRANSIENT-
STATE FLOW IN SAND,
Elzeftawy, A., Mansell, R.S.
Florida University, Gainesville. Department of Soil Science.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 599-603, July-
August 1975. 5 fig, 2 tab, 25 ref.
Descriptors: *Hydraulic conductivity, *Unsaturated flow, *Steady flow, *Unsteady
flow, Sands, Moisture content, Soil water movement, Pore pressure, Nuclear mois-
ture meters, Tensiometers, Pressure head, Cores, Laboratory tests. Soil density,
Infiltration, Depth, Drainage.
Using a method employed by Green and Corey (.1971) , hydraulic conductivity was
calculated as a function of water content for Lakeland fine sand. A gamma ray
transmission method for measuring soil water content and a tensiometer-pressure
transducer arrangement for measuring soil water suction were also used to experi-
mentally determine values of hydraulic conductivity for a similar range of soil
water contents in undisturbed soil cores and hand-packed soil columns. Measured
and calculated values were in good agreement for steady flow. During transient
flow soil water content was observed to be a non-unique function of suction for
water desorption, but depended upon the state of flow. Higher water contents
were found at a given pressure head during unsteady flow than during steady flow
or static equilibrium (zero flow). Graphs of water content versus soil water
suction were similar for cases of steady and no-flow conditions. For transient
flow, the soil-water pressure depended upon the soil-water content and rate of
change of pressure head with time.
75:02G-058
LINEAR DISPERSION IN FINITE COLUMNS,
Parlange, J.-Y., Starr, J.L.
Connecticut Agricultural Experiment Station, New Haven.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 817-819, September-
October 1975. 2 fig, 6 ref.
Descriptors: *Dispersion, *Solutes, *Soil water movement, Profiles, Boundary
processes, Equations, Mathematical models, Soil moisture, Pore water, Velocity.
The effect of the finite length of a soil column on the miscible displacement of
a solute was analyzed. The boundary conditions at both ends of the column
affected the breakthrough curve, while only the boundary condition at the entrance
of the column affected the profile within the column to any extent. The inter-
action between boundary conditions and column length was such that while the
breakthrough curve is essentially that given by the standard solution for a semi-
infinite column, even for relatively short columns, the concentration profile
was greatly affected by the finite length of the soil column.
75:020-059
RELATIONSHIPS BETWEEN THE HYDRAULIC CONDUCTANCE OF SURFACE CRUSTS AND SOIL
MANAGEMENT IN A TYPIC HAPLUDALF,
Falayi, 0., Bouma, J.
Soil Survey Institute, Wageningen (Netherlands).
Soil Science Society of America Proceedings, Vol. 39. No. 5, p 957-963,
October 1975. 8 fig, 3 tab, 36 ref.
49
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Descriptors: *Hydraulic conductivity, *Soil management, Runoff, Soil erosion,
Cultivation, Rotations, On-site investigations, Simulated rainfall, Soil aggre-
gates, Soil properties, Infiltration, Loam, Equipment, Storage, Pores, Corn(Field),
Steady flow.
The effect of different soil management, in terms of soil tillage and crop rota-
tion, on soil crusting was investigated by applying continuous artificial rain
(8.5 cm/hr) to experimental plots until steady-state conditions were reached.
Comparisons were made with bare plots subjected to natural rainfall for a period
of 4 months. Significant differences in soil roughness between the plow only
and the plow, disk, and harrow treatments resulted in higher infiltration and
longer times to incipient runoff for the plow treatment. However, differences
in surface roughness and infiltration and runoff rates were insignificant among
treatments when steady-state conditions were reached after only 2 hours. Crust
conductances, measured in situ, were significantly lower in the plow, disk, and
harrow treatments for the sod as compared with the continuous corn rotation.
Crusts had a significantly higher conductance when formed on top of clods as com-
pared with crusts formed between clods in the plow treatment. Conductances of
crusts formed under short-term high-energy experimental rainfall were not signi-
ficantly different from those formed under natural conditions, the latter charac-
terized by intermittent low-energy rainfall during a 4-month period. However,
their morphology was significantly different.
75:02G-060
DYNAMIC SIMULATION OF WATER STORAGE IN FALLOW SOIL AS AFFECTED BY MULCH OF
HYDROPHOBIC AGGREGATES,
Hillel, D.I., van Bavel, C.H.M., Talpaz, H.
Texas A and M University, College Station. Department of Soil and Crop Sciences;
and Texas Agricultural Experiment Station, College Station.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 826-833, September-
October 1975. 7 fig, 1 tab, 16 ref, 1 append.
Descriptors: *Dynamic programming, *Storage, *Fallowing, *Mulching, *Soil aggre-
gates, Numerical analysis, Water balnace, Cycles, Infiltration, Evaporation,
Soil properties, Hydraulic properties, Rainfall intensity. Runoff/ Agricultural
runoff, Drainage, Moisture content, Soil moisture, Water conservation, Soil man-
agement. Water management(Applied), Crop production, Groundwater recharge, Model
studies.
A mechanistic numerical model, based on fundamental physical principles and writ-
ten in IBM S/360 CSMP language, was designed to compute the dynamic balance of
water in a fallow soil through repeated cycles of infiltration and evaporation.
The necessary inputs are: (1) hydraulic characteristics of the soil and of the
surface crust of mulch layer, (2) duration and intensity characteristics of rain-
storms or irrigations, and (3) the potential evaporation rate as it varies diur-
nal ly and from day to day. The output provides time-dependent rates and cumula-
tive quantities of infiltration, runoff, surface detention, evaporation, internal
drainage and changes in water content of different layers and of the profile as
a whole. Computations carried out for a 4-day simulation (including two rain-
storms and four evaporation cycles) illustrated the use of the model for uniform,
crusted or mulched soil and predicted that the presence of a mulch of hydrophobic
aggregates, several centimeters thick, can greatly increase the quantity of water
absorbed and retained in the profile. This finding accorded with previously-
published experimental results and indicated a promising approach to soil manage-
ment for water conservation in dryland and irrigated farming.
75:02G-061
DEFLECTION-STIFFNESS CHARACTERISTICS OF CORRUGATED PLASTIC TUBING,
Schwab, G.O., Drablos, C.J.W.
Ohio Agricultural Research and Development Center, Columbus, Ohio.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975. Chicago, Illinois. 11 pg, 2 fig, 4 tab, 8 ref.
Descriptors: *Plastics, *Plastic deformation, *Plastic pipes, Drainage, Drainage
practices, Equipment, Pipes.
50
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Deflection of corrugated plastic tubing from repLicated field tests and from farm
installations in Ohio, Indiana, and Illinois was measured after one to four years
following installation. Commercial tubing sizes varied from 102 to 381 mm (4 to
15 in.) in diameter. The purpose of this study was to confirm present standards
and to collect supporting data for development of standards for large-size tubing.
In the replicated tests from two manufacturers 102-mm (4-in.) tubing deflection
decreased nearly linearly with an increase in stiffness. Maximum deflections
after 4 years were less than 17 per cent. All but one test sample was below ASTM
F405-74 stiffness standards. About 80 per cent of the deflection occurred during
the first two years with essentially no difference between the third and fourth
year. Average differences in deflection for 60- and 120-degree groove angles
were within 2 mm (0.08 in.) or less than the accuracy of measurement.
75:02G-062
PREDICTED VERSUS MEASURED DRAINABLE POROSITIES,
Skaggs, R.W., Wells, L.G., Ghate, S.R.
North Carolina State University, Raleigh, 27607.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois, 20 p, 8 fig, 3 tab, 9 ref.
Descriptors: *Drainage engineering, *Drainage practices, Drains, Soil water,
Soil water movement, Cores, Soil tests. Soil investigations.
Experiments were conducted on large field cores to determine the relationship
between drainage volume and water table depth for five soils. The measured drain-
age volumes were less than predicted from the soil water characteristics for all
but one soil, for which measured and predicted results were in good agreement.
Drainable porosities were calculated from both theoretical and experimental drain-
age volume-water table depth relationships by assuming that the unsaturated zone
is essentially 'drain to equilibrium" to the water table. The experimental
drainable porosities thus obtained were less than observed.
75:02G-063
AN EXPERIMENT WITH A LINEARLY INCREASING SPACING OF SUBSURFACE DRAINS,
Broughton, R.S., Tu, C.K-W.
McGill University, Macdonald Campus at Sante Anne de Bellevue, Quebec, Canada
HOA ICO.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois, 23 p, 9 fig, 3 tab, 10 ref.
Descriptors: *Drainage, *Drainage effects, *Drainage practices, *Drainage systems,
Crop response, Soil water. Soil water movement.
Subsurface drainage systems with diagonal drains between parallel drains were
installed to give spacings varying continuously 6 to 60m on a minimum of land.
Three drain depth replicates were used. Indications of the effects of depth and
spacing of drains on water table depths, maize yields and soil trafficability
were provided.
75.-02G-064
EFFECT OF OPENINGS ON INFLOW INTO CORRUGATED DRAINS,
Bravo, N.J-, Schwab, G.O.
The Ohio State University, Columbus, Ohio, Ohio Agricultural Research and
Development Center.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 13 p, 6 fig, 3 tab, 11 ref.
Descriptors: *0rifices, *0rifice flow, *Drainage, *Drainage engineering, *Drain-
age practices, Mathematical models, Model studies.
The relative effectiveness of the openings in corrugated plastic drains, a^
influenced by the presence of soil within the corrugations and within thp onenings
51
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themselves was evaluated from the standpoint of water inflow for saturated
conditions in a homogeneous, isotropic soil using a three-dimensional electric
analog and mathematical models.
75:02G-065
SOIL MOISTURE REGIME WITH SUBIRRIGATION,
Vallderuten, R., Ligon, J.T., Lambert, J.R.
University del Valle, Cali, Colombia.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975. Chicago, Illinois. 29 p, 14 fig, 14 ref.
Descriptors: *Soil moisture, *Irrigation, *Subsurface irrigation, *Model studies,
Simulation analysis, Soil-water-plant relationships, Climatic data.
A simulation model was developed to predict the soil moisture regime with subirri-
gation. Conclusions drawn from the performance of the model are state as follows:
a) the simulation model incorporating some plant physical characteristics, soil
and water properties, and climatic variables, gave reasonable results; b) the
physical process of water movement from the water table through the root system
under subirrigation conditions is highly related to the evaporative losses at
the surface; c) water uptake by the root system is influenced by the root distri-
bution and by the hydraulic characteristics of the soil; d) a relatively small
portion of the roots located in the vicinity of the water table are responsible
for a large part of the water uptake; and e) further studies involving a fluctu-
ating water table in heterogenous soils are needed to obtain a simulation model
more representative of the actual case.
75:02G-066
LEAF WATER POTENTIAL AND MOISTURE BALANCE—FIELD DATA,
Huck, M.G., Browning, V.D., Young, R.E.
Agricultural Engineering Department, Agricultural Experiment Station, Auburn,
Alabama.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975. Chicago, Illinois. 15 p, 6 fig, 2 tab, 13 ref.
Descriptors: *Root development, *Root distribution, *Root system, Soil moisture,
Soil water, Soil-water-plant relationships, Irrigation, Irrigation practices,
Transpiration.
The experimental hypothesis stated at the outset that increased root growth in a
larger soil reservoir will make additional water available to the plant was
tested and largely proved to be true. However, the corrollary, based on a sug-
gestion that increased water potential will permit a more rapid growth of cotton
plants, has been cast into serious doubt. If the osmotic component of leaf water
potential is neglected, the accumulated data from 3 years of field experiments
strongly suggest that plants growing under these conditions have a slightly lower
leaf water potential when the availability of additional soil water permits
growth of a larger plant with a higher transpirational demand.
75:02G-067
PLANT WATER STRESS CRITERIA FOR IRRIGATION SCHEDULING,
Stegman, E.G., Schiele, L.H., Bauer, A.
Agricultural Engineering Department, North Dakota State University, Fargo, North
Dakota.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 22 p, 7 fig, 6 tab, 18 ref.
Descriptors: *Soil water, *Soil moisture, *Soil-water-plant relationships,
Scheduling, Crop response, Plant physiology. Plant tissues, Stress, Stress analy-
sis, Irrigation, Irrigation effect.
This study was conducted to determine the potential for relating plant water
stress development to variables indicative of prevailing soil and atmospheric
52
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environments. Given such relationships irrigation scheduling services should
be better able to use plant stress oriented criteria for determining when to
irrigate. Stress development was evaluated by leaf xylem pressure and stomatal
diffusion resistance measurements. Data sets were obtained for 4 to 5 crops at
two irrigation Branch Stations in North Dakota. The two sites provided soil
types with differing hydraulic properties and available water holding capacities
Leaf xylem pressure data for each crop-soil combination were correlated by re-
gression procedures with ambient air temperatures and root zone soil moisture
content. Subsequent application of these xylem pressure levels as critical limits
to each regression model permitted estimation of allowable root zone soil moisture
depletion relative to expected ambient air temperatures. This procedure offers
a method for interpreting water balance estimates of soil moisture deficit and
advance forecasts of daily maximum air temperatures for need of irrigation.
75:020-068
STABILITY ANALYSIS OF INFILTRATION,
Philip, J.R.
Commonwealth Scientific and Industrial Research Organization, Canberra (Australia),
Division of Environmental Mechanics.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1042-1049, November-
December 1975. 1 tab, 21 ref, 1 append.
Descriptors: *Infiltration, *Stability, Mathematical studies, *Equations,
*Seepage, Gravitational water, Infiltration rates, Movement, Percolation, Ponding,
Soil moisture, Soil water movement, Unsaturated flows, Laboratory tests, Hydro-
dynamics, Model studies, Water pressure, Soils.
A rigorous hydrodynamic stability analysis of the delta-function model of infil-
tration was developed. Raats recently proposed as the criterion for instability
that wetting front velocity should increase with front penetration. This detailed
analysis, on the other hand, showed that the fundamental criterion is that the
water pressure gradient immediately behind the front should oppose the flow. The
two criteria agree only in the special case where five significant parameters of
the system are all constant and independent of depth, or of depth to the front.
The Raats criterion fails in the various more general cases with one or more of
these quantities variable. Care should be exercised in applying results for the
delta-function model to flows with gradual wetting fronts, expecially when non-
wetting strata are involved.
75:026-069
REDOX POTENTIAL IN IRRIGATED DESERT SOILS AS AN INDICATOR OF AERATION STATUS,
Meek, B.D., Grass, L.B.
Imperial Valley Conservation Research Center, Brawley, California.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 870-875, Sept-Oct.
1975. 10 fig, 2 tab, 15 ref.
Descriptors: *Oxidation-reduction potential, *Irrigation effects, *Soil-water-
plant relationships, *Sierozems, Sprinkler irrigation, Flood irrigation, Soil
moisture, Soil microorganisms, Arid lands, Environmental effects, Soil temperature,
Soil tests, Aeration.
Six experiments were designed to evaluate the effects of temperature, flooding
time, soil water content, and energy source on the redox potential (Eh) of
irrigated desert soils. Field heterogeneity required the use of 10 to 20 elec-
trodes placed in a 30-cm square to characterize a treatment. Eh varied over a
short distance, with no effects due to poisoning or erratic electrode readings;
a 5 C temperature increase at the 15-cm depth caused a 50-mV drop in redox poten-
tial. Soil saturation time correlated directly with Eh decline; Eh decreased less
during drip or sprinkler irrigation than when soil was flooded. To lower Eh,
soil moisture must be increased beyond a critical value to seal the surface to
atmospheric oxygen. Measurement of the oxygen diffusion rate and quantities of
iron or manganese in the soil solution will aid determination of the soil s
aeration status.
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75:020-070
A WATER MANAGEMENT MODEL FOR HIGH WATER TABLE SOILS,
Skaggs, R.W.
North Carolina State University, Raleigh, 27607.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975. Chicago, Illinois. 27 p, 9 fig, 1 tab, 20 ref.
Descriptors: *Water management, *Computer model, *Model studies, Soil water.
A water management computer model is being developed to simulate the soil water
regime for high water table soils. The model is based on a water balance in the
soil profile. Approximate methods are used to evaluate infiltration, subsurface
drainage, ET, subirrigation, and the soil water distribution within the profile.
Inputs to the model are soil properties, parameters of the surface and subsurface
drainage systems, and meteorological data. The model provides the capability of
predicting the response of the water table and the soil water regime above the
water table to rainfall, ET, given degrees of surface and subsurface drainage,
and the use of water table control or subirrigation practices. When finally
tested and completed the model can be employed to evaluate alternative water man-
agement systems and operational procedures by simulating their performance over
several years of record. Results of a field experiment to test the validity of
the model are presented. Examples of the use of the model for water management
system design and evaluation are given.
75:02G-071
EFFECT OF AGRICULTURAL DRAINAGE ON WATER QUALITY,
Smolen, M.D., Rasnake, M., Shanholtz, V.O.
Virginia Polytechnic Institute and State University, Southern Piedmont Center and
Department of Agricultural Engineering, Blackstone, Virginia.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 9 p, 5 fig, 4 ref.
Descriptors: *Return flow, *Drainage, Water quality, Water pollution, Model
studies, Water chemistry, Nitrogen, Nitrates, Irrigation effects.
Presentation of preliminary results from a modeling and monitoring study which
compares chemical quality data from adjacent agricultural and non-agricultural
areas. Increased levels of nitrate-nitrogen were detected in field draining
streams following the first period of agricultural activity. Results are dis-
cussed in terms of a planned comprehensive chemical transport study.
75.-02G-072
MODELING SOIL WATER MOVEMENT FOR TRICKLE IRRIGATION,
Warrick, A.W., Lomen, D.O.
Arizona University, Tucson. Department of Soils, Water and Engineering.
Available from the National Technical Information Service, Springfield, Va.
22161 as PB-248 048, $3.50 in paper copy, $2.25 in microfiche. Project Completion
Report, October 1975. 17 p, 14 fig, 3 tab, 21 ref.
Descriptors: *Unsaturated flow, Irrigation, *Soil water movement, Equations,
Evapotranspiration, Model studies, *Soil moisture, Flow rates, *Arizona, Flow
measurement, Measurement, *Mathematical models.
Solutions of the time dependent linearized soil moisture flow equation have been
completed for point, line, strip, disc and ring sources. These solutions were
used to simulate time dependent moisture regimes for various geometries used in
trickle irrigation. They are also useful as a check for elaborate finite differ-
ence or finite element schemes for solving the non-linear moisture flow equations.
For one-dimensional steady state flow, analytical solutions were obtained for
seven types of plant water withdrawal functions depending on the flux potential
as well as the depth below the surface. The solution of the linearized moisture
flow equations with a point source has been compared with the finite difference
solution of the non-linear equations of Brandt et al, as well as with field data
54
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measured on sandy soil in Yuma and the Sinai. These comparisons were very favor-
able but demonstrated that care must be taken in applying the model to problems
involving large fluxuations in moisture content. Two field experiments for mea-
suring evapotranspiration under trickle irrigation were made in citrus groves
near Yuma. The ob:ectives of these measurements were to study the water uptake
distribution in the close vicinity of a tree and the microclimate of a grove under
trickle irrigation. Data obtained during these field trips will be used to anal-
yze the irrigation policy of the farmers in Yuma and to compare with the predic-
tions of the corresponding mathematical models.
75:02G-073
THE CALCULATION OP STEADY-STATE WATER-TABLE HEIGHTS IN DRAINED SOILS BY MEANS OF
THE FINITE-ELEMENT METHOD,
Gureghian, A.B., Youngs, E.G.
Cambridge University, (England). Department of Applied Biology.
Journal of Hydrology, Vol. 27, No. 1/2, p 15-32, October 1975. 13 fig, 1 tab,
30 ref.
Descriptors: *Subsurface drainage, *Soil water, *Finite element analysis, *Math-
ematical studies, *Numerical analysis, *Water table, Equations, Steady flow,
Drains, Drainage systems, Percolation, Soil water movement. Saturated flow, Ground-
water, Mathematical models.
The use of a Galerkin-type finite-element method for the solution of steady-state
drainage problems in both homogeneous and heterogeneous soils was described. The
numerical procedure was shown to give satisfactory water-table heights in parti-
cular cases of ditch drainage in uniform and layered soils with given incident
rainfall. The use of the method in more complex situations was illustrated with
an example of a drained layered soil in which the backfill over a pipe drain
created a vertical band of soil of different hydraulic conductivity.
75:020-074
THE WATER TABLE AND THE NEUTRON MOISTURE METER,
Visvalingam, M.
Hull University (England). Department of Geography; and Durham University
(England). Department of Geography.
Journal of Hydrology, Vol. 27, No. 3/4, p 331-337, December 1975. 4 fig, 4 ref.
Descriptors: *Water table, *Neutron activation analysis. Neutron absorption,
Soil moisture, Saturated soils, Soil profiles, Piezometers, Tubes, Moisture meters,
Measurement, On-site investigations, Zone of saturation, Nuclear meters.
Measurements with a neutron meter were conducted in the University of Hull Catch-
water Catchment in East Yorkshire, close to the Hydrological Station at Westlands.
A tile drained plot, 50 ft square, with a relative relief of less than 1 ft, was
selected in a boulder-clay site under pasture. Instrumentation included access
tubes for the neutron probe and well-point techniques, such as piezometers and
cased auger holes using polyvinyl chloride (PVC) tubes. The meter was manufactured
by Nuclear Enterprises (G.B.) Ltd. The 21.5 in long moisture probe, 1.5 in in
diameter, consisted of a 30-mC241 Am-Be source, side placed on a BF sub 3 propor-
tional counter. The aluminum-alloy access tubes used were a standard 4 ft in
length. They were driven into slightly undersized auger holes, leaving 6 in pro-
truding above the surface. Measurements showed count rates at capillary saturation
to be within the error limits of count rates at full saturation. However, the
saturation profiles in themselves indicated not only the zonation of the soil but
also differences in drainable porosity.
WATERGMOVEMENT WITHIN THE ROOT ZONE OF IRRIGATED AND NONIRRIGATED GRAIN SORGHUM,
Stone, L.R., Horton, M.L. •.».„,«
South Dakota State University, Brookings. Department of Plant Science.
Journal of Soil and Water Conservation, Vol. 30, No. 6, p 292-293, November-
55
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December 1975. 3 fig, 7 ref.
Descriptors: *Soil water movement, *Root zone, *Grain sorghum, Irrigation,
Solutes, Nutrients, Grains(Crops), Unsaturated flow, Evapotranspiration, Loam,
Tensiometers, Potentiometric level, Hydraulic conductivity, Darcys Law, Depth,
Salts, Soil profiles, Perched water.
Water movement and redistribution are important in supplying nutrients and water
to plants. Water movement and redistribution during August 1972 in fields of
irrigated and nonirrigated grain sorghum were determined. Soil water flux in the
non-irrigated area was upward in all soil-depth intervals during the study.
Upward flux in the 15- to 30-,30- to 50-, and 50- to 70- cm depths decreased with
time. Upward flux in the 130- to 150-cm depth reached a maximum of 0.17 cm per
day and then remained near 0.11 cm per day. Immediately after irrigation, flux
was downward in all soil depth intervals in the irrigated sorghum. Flux in the
130- to 150-cm depth remained downward. Flux in the 15- to 30-, 30- to 50-, and
50- to 70-cm depths turned upward within one week after irrigation.
75:02G-076
A PROCEDURE FOR THE SAMPLING AND TESTING OF LARGE SOIL CORES,
Watson, K.K., Lees, S.J.
Soil Science of America Proceedings, Vol. 39, No. 3, p 589-590, May-June 1975.
1 fig, 6 ref.
Descriptors: *Soil water, *Computer models, Soil properties, Soil investigations,
Soil moisture, Soil tests, Laboratory test.
The significance of acquiring reliable data on the soil-water characteristics of
field soils is discussed in relation to the input requirements of computer-based
numerical models of the unsaturated flow process. A specification outlining the
conditions to be fulfilled in sampling and testing a large soil core is then de-
tailed. Equipment used in extracting a 40-cm-diam soil core is described together
with relevant laboratory instrumentation.
75:02G-077
ANNOTATED BIBLIOGRAPHY ON TRICKLE IRRIGATION,
Smith, S.W., Walker, W.R.
Colorado State University, Fort Collins, Colorado.
Agricultural Engineering Department, Environmental Resources Center.
Information Series No. 16, June 1975. 61 p.
(See 75:03F-039)
75:02G-078
PERFORMANCE AND EVALUATION OF COMBINED MOLE-TILE DRAIN SYSTEM IN HEAVY SOILS,
Unhanand, K., Tuamsangiem, K.
Utah State University, Logan, Utah.
International Commission On Irrigation and Drainage Bulletin, p 36-52, January
1975. 24 fig, 4 equ, 15 ref.
Descriptors: *Drainage, *Drainage effects, *Drainage practices, *Drainage system,
*Drains, Soils, Soil water.
A field experiment was conducted to investigate the performance and cost of the
combined mole-drain systems in heavy soils in comparison with a similar tile drain
system. Three experimental plots consisted of a tile-drained plot, a combined
(single mole) drained plot and a combined (double mole) drained plot. They were
constructed with a tile drain spacing of 37 metres (120 feet) and a mole drain
spacing of 1.83 metres (6 feet). The experimental results show that the combined
systems were more effective than the drain system in lowering the water table.
The difference in the effectiveness of the single mole drains and double mole
drains was not distinctly apparent. No deterioration of the mole drains during
the period of two years tested was detected. The cost analysis indicated that the
annual cost of the combined systems is always less than that of an equivalent tile
56
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drain system even if the mole drains in the combined system have to be redrawn
every year.
75-.02G-079
A NUMERICAL MODEL FOR THE SIMULATION OF UNSATURATED VERTICAL FLOW OF MOISTURE
IN SOILS,
Wind, G.P., Van Doorne, W.
Institute for Land and Water Management Research, Wageningen (The Netherlands) .
Journal of Hydrology, Vol. 24, p 1-20, 1975. 2 fig, 4 tab, 19 equ, 6 ref.
Descriptors: *Model studies, *Mathematical models, *Soil water movement, *Soil
moisture, Soil investigations, Irrigation.
This paper describes a digital model for the simulation of non-steady unsaturated
vertical flow of moisture in soils. By using an integrated formula for flow
velocity, errors due to averaging two conductivity values are avoided. This con-
fines the applicability to situations in which the soil is not too dry. The model
also simulates the drainage process. So it produces the depth of the groundwater
table and the discharge data. Other output data are pool depth, runoff, flow
velocity at every depth, moisture content and tension for every layer. A discus-
sion is given on the errors caused by averaging conductivity values in models. A
chapter is dealing with oscillations caused by too large time steps. The time
steps must be chosen in such a way that errors will not be amplified but reduced.
The last chapter gives the costs of computation. For soils with low permeability
the model seems to be very cheap to run. A digital model as the one described
is fit for short runs with many soils. For long runs with one soil an analogous
model is more appropriate.
75:02G-080
THE OCCURRENCE AND REMOVAL OF NITROGEN IN SUBSURFACE AGRICULTURAL DRAINAGE FROM
THE SAN JOAQUIN VALLEY,
Brown, R.L.
California Department of Water Resources, Sacramento, California, 95814.
Water Research Vol. 9, No. 5/6, p 529-546, May-June 1975. 11 fig, 7 tab, 39 ref.
Descriptors: *Drainage, *Drainage effects, *Water treatment, *California, *Nitro-
gen. Waste water treatment, Water pollution, Return flow.
During the years 1967-1973 there have been extensive studies of subsurface agri-
cultural drainage in the San Joaquin Valley of California. These studies, by
cooperating state and federal agencies, were to determine the composition and
quantity of drainage waters produced from irrigated agriculture, to evaluate pos-
sible methods of removing problem constituents (mainly nitrogen) from these waters,
and to obtain an idea of the effectiveness of the treatment methods studied for
reducing the waters' biostimulatory content with respect to potential receiving
waters. ^
75:02G-081
INTERACTIONS BETWEEN ORGANIC COMPOUNDS, MINERALS, AND IONS IN VOLCANIC ASH DE-
RIVED SOILS: I. ADSORPTION OF BENZOATE, P-OH BENZOATE, SALICYLATE, AND PHTHALATE
IONS,
Appelt, H., Coleman, N.T., Pratt, P.F.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 623-627, July-
August 1975. 4 fig, 4 tab, 15 ref.
Descriptors: *Ions, *Organic compounds, *Adsorption, Soils, Soil investigations.
The adsorption, desorption, and competitive adsorption characteristics of benzo-
ate p-OH benzoate, salicylate, and phthalate were used as models to study the
possible mechanisms involved in the interactions of organic compounds with amor-
phous materials. The studies were carried out in batch systems using subsoil
samples of three Typic Dystrandept soils from Chile.
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75:020-082
AMMONIA VOLATILIZATION FROM SURFACE APPLICATIONS OF AMMONIUM COMPOUNDS ON
CALCAREOUS SOILS: IV. EFFECT OF CALCIUM CARBONATE CONTENT,
Fenn, L.B., Kissel, D.E.
Texas A&M Agriculture Research Center, El Paso, 79927.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 631-633, July-
August 1975. 2 fig, 2 tab, 9 ref.
Descriptors: *Ammonia, *Calcium carbonate, *Nitrogen, *Fertilizers, *Fertiliza-
tion, Soils.
The purpose of this study was to determine the effect of soil CaC03 content on
ammonia volatilization from surface applied ammonium compounds. Ammonia-nitrogen
losses from surface-applied (NH4)2S04 increased rapidly to 6.1% soil CaCO3, with
slight NH3 loss increases from 6.1 to 9.7% soil CaC03, and no NH3 loss increase
beyond 9.7% soil CaCO3. Ammonium nitrate reached maximum NH3-N loss at 1.3% soil
CaCO3 and 110 kg NH4+*-N/ha, with lower but still increasing losses of NH3-N at
6.1% soil CaCO3 and 550 kg NH4+N/ha.
75:02G-083
THE EFFECT OF SOIL PROPERTIES ON ZINC ADSORPTION BY SOILS,
Shuman, L.M.
Georgia University, Agricultural Experiment Stations, Experiment, Ga. 30212.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 454-458 May-June,
1975. 4 fig, 2 tab, 18 ref.
Descriptors: *Zinc, *Organic matter, *Clays, *Soils, *Soil investigations, *Sands,
Soil Chemistry, Soil texture.
Solutions containing eight different concentrations of Zn were equilibrated with
four soils sampled at two depths to determine whether Zn adsorption conformed to
the Langmuir isotherm and to relate the Langmuir coefficients to soil properties.
Zinc adsorption conformed to the Langmuir isotherm and two linear portions of the
curve were found. The adsorption sites for the lower part had very high bonding
energy coefficients and low adsorptive capacities compared with the adsorption
sites of the part of the curve corresponding to higher Zn concentrations in the
equilibrating solution. The CEC was related to the adsorptive capacity. The
lower part was equivalent to 23% of the CEC and the upper part to 76% of the CEC.
Soils high in clay or organic matter had higher adsorptive capacities and higher
bonding energies for Zn than sandy soils low in organic matter. More differences
in Zn adsorption were observed among soil types than between depths in each soil
type. A study of the effect of pH on the adsorption of Zn revealed that low pH
reduced Zn adsorption more for the sandy soils than for those high in colloidal-
size materials.
75:02G-084
VARIATIONS IN PICLORAM LEACHING PATTERNS FOR SEVERAL SOILS,
Ping, C.L., Cheng, H.H., McNeal, B.L.
Washington State University, Pullman 99163.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 470-473, May-June
1975. 3 fig, 2 tab, 9 ref.
Descriptors: *Leaching, Soils, Soil investigations, Soil texture, Pesticides,
Diffusion.
Laboratory studies of picloram leaching under saturated conditions were conducted
for four soils. Leaching patterns could be related to variations in soil texture
and pore uniformity for three soils from arid and semiarid regions. Diffusion from
conducting pores into adjacent micropores appeared to be the most plausible expla-
nation of leaching patterns obtained for an Oxisol of volcanic origin from Hawaii.
Evidence supporting the presence of the postulated micropore structure in this
tropical soil was obtained from constancy in flow rate, from scanning electron
micrographs, and from picloram recovery at a reduced leaching rate.
58
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75:020-085
EFFECT OF HYSTERESIS ON THE PREDICTION OF INFILTRATION, REDISTRIBUTION AND DRAIN-
AGE OF WATER IN A LAYERED SOIL, UXXUIM «INU UKAJ.M
Dane, J.H., Wierenga, P.J.
Colorado State University, Fort Collins, Colorado. Department of Agronomy
Journal of Hydrology, Vol. 25, p 229-242, 1975. 18 fig, 2 tab, 18 ref.
Descriptors: *Hysteresis, *Soil water movement, *Infiltration, Infiltration
rates, Drainage, Soil water.
In order to study the effect of hysteresis on soil water movement a large soil
column, filled with Glendale clay loam over a river sand, was flood-irrigated with
10 cm water. The infiltration rate, wetting front advance, water content redistri-
bution, and the amount of drainage water was measured. A computer model, using
S/360 CSMP, was developed to simulate the flow behavior. The main drying and
main wetting curves in the soil water tension-water content, and in the hydraulic
conductivity-water content relationships were provided in the computer model. From
these relationships, scanning curves were developed to simulate hysteretic flow
behavior under both wetting and drying conditions. Experimental data were com-
pared with data computed from either the main drying, the main wetting, or the
scanning curves. Infiltration was accurately predicted using the main wetting
curves. However, redistribution and drainage were better predicted when hystere-
sis was taken into account.
75:02G-086
DESCRIPTION OF WATER AND AIR MOVEMENT DURING INFILTRATION,
Brustkern, R.L., Morel-Seytoux, H.J.
Montana State University, Bozeman, Montana. Department of Civil Engineering.
Journal of Hydrology, Vol. 24, p 21-35, 1975. 10 fig, 12 equ, 4 ref.
Descriptors: *Infiltration, *Mathematical studies, Soil water movement, Porous
media, Capillary water.
An approximate analytical solution for the problem of one-dimensional infiltration
into a homogeneous porous medium is presented. The solution is made possible by
assuming that capillary pressure can be partially neglected. Two equations in-
volving two unknowns, water saturation and total velocity, are derived and then
solved in a step-wise fashion to yield the saturation profile and the total velo-
city at any time. Infiltration quantities are obtained by integration of the area
under the saturation profile. Analytical concepts and procedures relevant to the
determination of the evolving saturation profile are discussed in some detail.
Particular attention -is given to the nature and behavior of the fractional flow
function. The occurence of air counterflow during infiltration is also discussed.
75:02G-087
THE EFFECT OF PERMEABLE SURROUNDS ON THE PERFORMANCE OF CLAY FIELD DRAINAGE PIPES,
Dennis, C.W., Trafford, B.D.
Field Drainage Experimental Unit, Anstey Hall, Trumpington, Cambridge (Great
Britain).
Journal of Hydrology, Vol. 24, p 239-249, 1975. 7 fig, 2 tab, 4 equ, 18 ref.
Descriptors: *Drainage, *Drains, *Drainage effects, Drainage design, Soil water,
Soil water movement.
The relative performances of a plain clayware drain and ones with a partial and
a complete gravel surround were investigated by measuring the drain discharge rate
from each during ponded conditions when installed in a sand tank. From the drain
discharge the effective radius of each drain installation was calculated and these
values used in the hodograph solution of the drainage problem to obtain steady
state theoretical relationships between water-table height and drain discharge.
Comparison of the values with those observed in experiments in the sand tank re-
vealed reasonable agreement.
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75:02G-088
THE EFFECT OF THE DEPTH OF AN IMPERMEABLE BARRIER ON WATER-TABLE HEIGHTS IN
DRAINED HOMOGENEOUS SOILS,
Youngs, E.G.
Agricultural Research Council, Unit of Soil Physics, Cambridge (Great Britain).
Journal of Hydrology, Vol. 24, p 283-290, 1975. 5 fig, 12 equ, 13 ref.
Descriptors: *Impervious membranes, Soils, Water table, Drainage, Drainage
effects, Model studies.
The water-table height in a drained homogeneous soil at a given rainfall rate is
greater the closer an impermeable barrier is below the drain. Upper and lower
limits for the water-table height, between which the true value lies, are estima-
ted from theoretical considerations. These show that the lower the rainfall rate
for a given depth of impermeable barrier the greater is the effect on the water-
table height. Hydraulic model and electric analogue experiments are in agreement
with these results.
75:02G-089
RELATIONSHIPS BETWEEN THE DENITRIFICATION CAPACITIES OF SOILS AND TOTAL, WATER-
SOLUBLE AND READILY DECOMPOSABLE SOIL ORGANIC MATTER,
Burford, J.R., Bremner, J.M.
Iowa State University, Department of Agronomy. Department of Soil Science, Univer-
sity of Reading, London Road, Reading, Berks RG1 5AQ, England.
Soil Biology & Biochemistry, Vol. 7, No. 6 p 389-394, November 1975. 5 fig, 3 tab,
13 ref.
Descriptors: *0rganic matter, *Denitrification, Soils, Soil investigation, Soil
chemistry, Nitrogen, Anaerobic conditions.
The relationships between the denitrification capacities of 17 surface soils and
the amounts of total organic carbon, mineralizable carbon, and water-soluble
organic carbon in these soils were investigated. The soils used differed marked-
ly in pH, texture, and organic-matter content. Denitrification capacity was as-
sessed by determining the N evolved as N2 and N20 on anaerobic incubation of ni-
trate-treated soil at 20 degrees C for 7 days, and mineralizable carbon was
assessed by determining the C evolved as C02 on aerobic incubation of soil at 20
degrees C for 7 days. The denitrification capacities of the soils studied were
significantly correlated with total organic carbon and very highly correlated with
water-soluble organic carbon or mineralizable carbon. The amount of nitrate N
lost on anaerobic incubation of nitrate-treated soils for 7 days was very closely
related to the amount of N evolved as N2 and N20.
75:02G-090
SOIL ORGANIC MATTER FRACTIONS AS SOURCES OF PLANT-AVAILABLE SULPHUR,
Freney, J.R., Melville, G.E., Williams, C.H.
Division of Plant Industry, CSIRO, Canberra, 2601 Australia.
Soil Biology & Biochemistry, Vol. 7, No. 3, p 217-221, May 1975. 1 fig, 5 tab,
21 ref.
Descriptors: *0rganic matter, *Sulphur, Soils, Soil investigations, Soil-water-
plant relationships.
Pot culture experiments are described which attempt to identify the organic frac-
tions of soil sulphur that decompose during the growing season to provide plant-
available sulphur. Soil organic matter was labelled with 35S by incubating soil
with labelled sulphate and several organic sulphur fractions were determined be-
fore and after the growth of Sorghum vulgare and following a fallow treatment.
The effect of moisture stress on the uptake of sulphur plants was also investigated;
this treatment had little effect.
75:02G-091
DISAPPEARANCE OF NITRATE UNDER TRANSIENT CONDITIONS IN COLUMNS OF SOIL,
60
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Doner, H.E.
California University, Berkeley, Department of Soils and Plant Nutrition. Berkeley,
California 94720.
Soil Biology & Biochemistry, Vol. 7, No. 4/5, July 1975. p 257-259 3 fiq
8 ref.
Descriptors: *Nitrate, *Flow rate, Soil investigations. Soil chemistry, Leaching,
Soil texture.
Previously a rapid reduction of NO3 was obtained in soil columns with continuous
flow, before the establishment of steady state conditions. This initial behavior
was not a function of flow rates. In order to determine what influence N03 con-
centrations might have on transient and steady state rates, of N03 loss, small
soil columns were infiltrated with 0, 100, and 1000 micrograms ml(-l)N03-N and
the effluents were analyzed daily for N03 and NO2.
75:020-092
SHORT TERM NITRATE LOSSES AND ASSOCIATED MICROBIAL POPULATIONS IN SOIL COLUMNS,
Doner, H.E., Volz, M.G., Belser, L.W., Loken, Jan-Per.
California University, Department of Soils and Plant Nutrition, Berkeley, Califor-
nia 94720.
Soil Biology & Biochemistry, Vol. 7, No. 4/5, p 261-263, July 1975. 1 fig, 15 ref.
Descriptors: *Nitrate, *Leaching, Soil investigations, Soils, Soil tests, Return
flow, Irrigation.
The relationship between NO3 loss from solution and associated microbial popula-
tions as a function of time and depth in soil was studied. Soil columns were
leached with a N03 solution under flooded conditions. Soil columns were cut into
top, middle and bottom sections following 4.5, 12, 24, 48 and 120 h of leaching.
Soil was subsequently analyzed for N03 and NO2 content and microbial counts were
made for denitrifiers, nitrate reducers and total microbial population. Nitrate
losses were found to be directly related to an increase in the denitrifier popu-
lation and proportional to the residence time of solution in the soil. The total
microbial population and nitrate reducer population remained nearly constant
throughout the experiment.
75:02G-093
FORMATION OF CHEMICAL AND BIOLOGICAL DENITRIFICATION PRODUCTS IN FLOODED SOIL
AT CONTROLLED pH AND REDOX POTENTIAL,
Van Cleemput, O., Patrick, W.H. Jr., Mcllhenny, R.C.
Louisiana State University, Agronomy (Soils) Department, Baton Rouge, Louisiana
70803.
Soil Biology & Biochemistry, Vol. 7, No. 4/5, p 329-332, July 1975. 3 fig, 1 tab,
13 ref.
Descriptors: *Denitrification, *Saturated soils, Soils, Soil investigations,
Chemical reactions.
The formation of denitrification products was studied in a waterlogged soil which
was treated with and without mercuric chloride. Before the addition of the ster-
ilant and N03-N the pH was controlled at45, 6 and 8 and the redox potential at 0
and +400 mV in stirred suspensions. Denitrification products N2, N20 and some
traces of NO were detected.
75:02G-094
TEMPERATURE EFFECTS ON AMMONIFICATION AND NITRIFICATION IN A TROPICAL SOIL,
Myers, R.J.K.
Division of Land Use Research, CSIRO, Canberra, A.C.T., Australia.
Soil Biology & Biochemistry, Vol. 7, No. 2, p 83-86, March 1975. 2 fig, 2 tab,
14 ref.
Descriptors: *Ammonification, *Nitrification, Soils, Soil investigations.
61
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Nitrogen, Temperature.
Ammonification of soil organic N and nitrification of ammonium-N was studied in
Tindall clay loam over a range of temperatures from 20-60 C. Nitrification rates
at each temperature were constant throughout the 28 day incubation, whereas most
of the ammonification occurred in the first 7 days.
75:02G-095
EFFECT OF ALTERNATE AEROBIC AND ANAEROBIC CONDITIONS ON REDOX POTENTIAL, ORGANIC
MATTER DECOMPOSITION AND NITROGEN LOSS IN A FLOODED SOIL,
Reddy, K.R., Patrick, W.H., Jr.
Louisiana State University, Laboratory of Flooded Soils and Sediments, Department
of Agronomy, Baton Rouge, Louisiana 70803.
Soil Biology & Biochemistry Vol. 7, No. 2, p 87-94, March 1975. 6 fig, 1 tab,
25 ref.
Descriptors: *Aerobic conditions, *Anaerobic conditions, Organic matter, Decom-
posing organic matter, Nitrogen, Nitrate, Denitrification.
The effect of several cycles of varying length of alternate aerobic and anaerobic
conditions on redox potential, organic matter decomposition and loss of added and
native nitrogen was investigated under laboratory conditions in flooded soil incu-
bated for 128 days. Redox potential decreased rapidly when air was replaced with
argon for the short-time cycles, but decreased more slowly where the aerobic
period was long enough to permit build-up of nitrate. The minimum redox potential
reached during the anaerobic period was generally lower for the longer cycles, but
in all cases was low enough for denitrification to occur. Rate of decomposition
of organic matter was faster in the treatments with a greater number of alternate
aerobic and anaerobic periods.
75:02G-096
MODEL FOR DECOMPOSITION OF ORGANIC MATERIAL BY MICROORGANISMS,
Parnas, H.
Utah State University, Ecology Center, Logan, Utah. 84322.
Soil Biology & Biochemistry, Vol. 7, No. 2, p 161-169, March 1975. 8 fig, 1 tab,
29 equ, 11 ref.
Descriptors: *Model studies, *Decomposing organic matter, *Organic matter, Micro-
organisms, Soil investigations.
A theoretical model which gives the rate of microbial decomposition of organic
material (plant or animal residues, or soil organic matter) is presented. Explicit
equations for the rate of decomposition, mineralizations, and immobilization are
given. The main assumption of the model is that the rate of decomposition of
any substrate is proportional to the growth rate of its decomposers. The main
results of the model are: 1. Addition of extra nitrogen to materials poor in
nitrogen increase their rate of decomposition; 2. Addition of extra nitrogen to a
substrate whose initial carbon/nitrogen ratio is above a critical ratio (20-30)
causes a decrease in the substrate's carbon/nitrogen ratio during its decomposi-
tion; 3. If the initial carbon/nitrogen ratio is below the critical one, no change
in the substrate's ratio will occur with time; 4. Net mineralization of organic-
nitrogen mineralization but not necessarily the rate of net mineralization. All
the model results are analytical and independent of the values for the various
parameters. Nevertheless the application of the model to real field conditions
is discussed while presenting a numerical example.
75:02G-097
EFFECT OF PLOUGHING AND DIRECT DRILLING ON SOIL NITRATE CONTENT,
Dowdell, R.J., Cannell, R.Q.
Agricultural Research Council Letcombe Laboratory, Wantage, Oxon.
Journal of Soil Science, Vol. 26, No. 1, p 53-61, March 1975. 2 fig, 2 tab, 26 ref.
Descriptors: *Nitrate, Cultivation, Soil, Soil investigations.
62
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The concentration of nitrate-N at 30 cm depth in a clay soil was 2-5 times great-
er after ploughing than after direct drilling during the winter and spring of
1972-73. However, by early May no significant differences could be detected be-
tween cultivation treatments. It is concluded that decreased mineralization of
soil nitrogen in the direct-drilled soil is the main factor responsible for the
differences observed.
75:020-098
GRAPHICAL REPRESENTATION OF TRICATIONIC EXCHANGES WHERE ONE OF THE CATIONS IS THE
PROTON,
Andre, J.P.
Station d'Agronomie et de Physiologie Vegetale, 06600—Antibes, France.
Journal of Soil Science, Vol. 26, No. 1, p 81-92, March 1975. 5 fig, 16 equ,
1 ref.
Descriptors: *Model studies. Cation exchange, Soils, Soil investigations.
Most constituents of the adsorbing complex of the soil are cationic exchangers
with variable exchange capacity: it is possible to study graphically exchanges
involving the protons and two other cations. The representation developed here
uses and generalizes the principle of the bicationic exchange isotherms in a
square diagram. This helps to explain some experimental phenomena and enables the
final equilibria of the exchange reactions to be forecast. The model seems useful
for application in agronomy and physiology.
75:02G-099
INTERACTIONS BETWEEN ORGANIC COMPOUNDS, MINERALS, AND IONS IN VOLCANIC-ASH-DERIVED
SOILS: II. EFFECTS OF ORGANIC COMPOUNDS ON THE ADSORPTION OF PHOSPHATE,
Appelt, H., Coleman, N.T., Pratt, P.F.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 628-630, July-
August 1975. 5 tab, 16 ref.
Descriptors: *Qrganic compounds, *Ions, *Adsorption, *Phosphate, Soils, Soil
investigations.
The effects of organic compounds on phosphate adsorption by volcanic-ash-derived
soils were studied using benzoate, p^OH benzoate, salicylate, and phthalate, and
by humic and fulvic acids extracted from a surface soil sample of a Typic Dys-
trandept. The adsorption of simple organic anions that are specifically adsorbed
block to some extent the adsorption sites for nonspecifically adsorbed anions such
as chloride and/or nitrate. But, organic anions did not compete for or block ad-
sorption sites for phosphate anions, because of the much higher affinity of phos-
phates for the adsorption sites in these volcanic-ash-derived soils.
75:02G-100
SPECIFIC ADSORPTION OF TRACE AMOUNTS OF CALCIUM AND STRONTIUM BY HYDROUS OXIDES
OF IRON AND ALUMINUM,
Kinniburgh, D.G., Syers, J.K., Jackson, M.L.
Massey University, Palmerston North, N.Z.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 464-470, May-June
1975. 5 fig, 1 tab, 17 ref.
Descriptors: *Iron, *Aluminum, *Adsorption, Chemical analysis, Chemical properties,
Chemical reactions.
Freshly prepared Fe and Al hydrous oxide gels and the amorphous product of heating
gibbsite selectively adsorbed traces of Ca and Sr from solutions containing a
large excess of NaNO3. The fraction of the added Ca (Sr) adsorbed depended prin-
cipally on the suspension pH, the amount of solid present, and to a lesser extent
on the NaNO3 concentration.
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75:02G-101
ON THE DIFFERENTIAL EQUATION FOR THE EQUILIBRIUM MOISTURE PROFILE IN SWELLING
SOIL,
Sposito, G.
California University, Riverside, Dept. of Soil Science and Agricultural Engi-
neering.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1053-1056, Novem-
ber-December 1975. 20 ref.
Descriptors: *Soil moisture, *Thermodynamics, Equations, *Equilibrium, *Expansive
soils, Overburden, Earth pressure. Atmospheric pressure, Profiles, Soil water,
Soil properties, Bulk density, Void ratio, *Moisture content, Physicochemical
properties.
Differential equations which describe the equilibrium vertical distribution of
moisture in swelling soil have been derived previously using both thermodynamic
and fluid-mechanical methods. A fundamental disagreement exists between these ex-
pressions which was resolved in this paper through a detailed thermodynamic analy-
sis of the equilibrium state of water in a swelling soil. The correct differential
equation for the moisture profile was found and the discrepancy between previous
results was shown to have been caused either by introduction of extra-thermodyna-
mic variables or by an incorrect handling of the effect of overburden pressure on
the soil water.
75:02G-102
PREDICTING IONIC DISTRIBUTIONS IN LARGE SOIL COLUMNS,
Wierenga, P.J., Shaffer, M.J., Gomez, S.P., O'Connor, G.A.
New Mexico State Univ., University Park.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1080-1084, November-
December 1975. 8 fig, 1 tab, 13 ref.
Descriptors: Irrigation effects, *Ions, *Soil profiles, *Soil chemistry, *Analyti-
cal techniques, *Distribution patterns, *Model studies, Chemical analysis, Evalu-
ation, Soil analysis, Soil chemical properties, Soil physical properties, Drainage
effects, Infiltration, Lysimeters, Instrumentation, Irrigation, Irrigation prac-
tice, Computer models, Soil water movement, *Return flow.
The distribution of various cations and anions was measured with depth and time
in a large lysimeter column periodically irrigate*'in saline water. Samples of
the soil solution were removed with extraction cups placed at depths of 25, 50,
75, 100, 125, and 150 cm below the soil surface in the lysimeters. Observed ionic
distributions were compared with calculated values obtained by combining transient
water flow model with a chemical plate theory model. Good agreement was obtained
in observing a predicted depth distribution profile for S04(—), Cl(-), Na(+), and
Ca(++). Soluble Mg(++) and HCO3(-) concentrations were overpredicted suggesting
that further refinement of the chemical subroutine may be needed.
75:02G-103
SEASONAL VARIABILITY OF RAINWATER REDISTRIBUTION BY FIELD SOILS,
Reid, I.
Birkbeck Coll., London (JEngland) .
Journal of Hydrology, Vol. 24, No. 1/2, p 71-80, April 1975. 4 fig, 3 tab, 31
ref.
Descriptors: *Rainfall disposition, *Infiltration, *Soil moisture, Moisture con-
tent Antecedent moisture content, Field capacity, Hysteresis, Soil moisture meters,
Permeability, Soil-water-plant relationships, Variability, Seasonal.
Seasonal differences in post-infiltration redistribution of rainwater were evalua-
ted for highly porous pasture soils. Winter soil drainage is precipitation-
dependent, while soil-moisture fluctuations are a function of the relationship be-
tween antecedent soil water-content and the seasonal mean and are largely independent
of infiltration quantities. Summer soil drainage is dependent upon both rainfall
64
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and differential soil absorption and was described by a linear multiple regression
model. The seasonal nature of redistribution is an important consideration of
catchment water disposition, and is useful as a control in the evaluation of opti-
mal irrigation practice under field conditions. Temporal changes in soil-moisture
response to rainfall exposed difficulties in the conceptualization of field capa-
city and soil-moisture deficit.
75:02G-104
MEASUREMENT OF HYDRAULIC CONDUCTIVITY AND DIFFUSIVITY FOR PREDICTING THE PROCESS
OF SOIL WATER INFILTRATION FROM A TRICKLE SOURCE,
Ben-Asher, J., Diner, N., Brandt, A., Goldberg, D.
University of the Negev, Beersheba (Israel). Research and Development Authority.
Water Resources Bulletin, Vol. 11, No. 6, p 1187-1196, December 1975. 5 fig, 6
ref.
Descriptors: *Soil water movement, *Infiltration, laboratory tests, *Diffusivity,
*Hydraulic conductivity, Unsteady flow, Mathematics, Equations, Moisture content,
Unsaturated flow, Soil moisture, Percolation, Permeability, Retention, Field capa-
city.
Two soil water functions, hydraulic conductivity K and diffusivity D, were estima-
ted by two methods. In one method D was estimated according to Bruce and Klute
(1956), and K was calculated from D and the retention curve. In the second, K was
obtained by field estimation, with D being calculated from K and the retention
curve. The criterion of reliability for both methods was agreement between exper-
imental and predicted distribution of soil water content. The prediction was
made using the functions K and D as soil water parameters in both methods. Theore-
tical and experimental agreement was generally good. The first method, however,
was found to be best for high soil water content and the second for low soil water
content. In addition, the water content at the end of the monotonic increase of
function D (estimated according to Bruce and Klute, 1956) was found to be about
the upper limit of field soil water content. It can be used as a boundary condi-
tion in the numerical solution of a cylindrical model of infiltration from a
trickle source. It was concluded that the best agreement between theory and ex-
periment can be found when the combined values of D and K from both methods of
estimation are used.
75:02G-105
SULFUR FRACTIONS AND CARBON-NITROGEN-PHOSPHORUS-SULFUR RELATIONSHIPS IN SOME
BRAZILIAN AND IOWA SOILS,
Neptune, A.M.L., Tabatabai, M.A., Hanway, J.J.
Iowa State University, Ames 50010
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 51-55 January-Febru-
ary 1975. 5 tab, 28 ref.
Descriptors: *Sulfur, Soils, Soil properties, Soil tests, Iowa, Carbon, Nitrogen,
Phosphorus.
Current knowledge concerning the percentage distribution of the various S fractions
in soils is mainly derived from studies of S in surface soils of temperate regions.
This study was conducted to determine the S fractions and C-N-P-S relationships
in some subtropical soils from Brazil and to compare the values in these soils with
those in soils of a temperate region from Iowa.
FERTILIZER OR SALT LEACHING AS AFFECTED BY SURFACE SHAPING AND PLACEMENT OF
FERTILIZER AND IRRIGATION WATER,
Kemper, W.D., Olsen, J., Hodgdon, A. „„,-,,
Colorado State University, Fort Collins, CO 80^ jamiarv-
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 115-119, January
February, 1975. 4 fig, 9 ref.
Descriptors: 'irrigation, 'Furrow irrigation, 'Surface irrigation, Fertilization,
Leaching, Root zone, Irrigation effects, Return flow.
65
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Irrigation in furrows and placement of fertilizer in bands in ridges was evalua-
ted as a means for allowing overirrigation to bypass nitrate and reduce leaching
losses. In a loamy sand, placement of band 0 to 5 cm higher than the surface of
water in the furrow allowed over 120 cm of overirrigation before the salt began
to leave the root zone. In the clay loam a similar delay of nitrate removal was
not achieved until the band .was 10 cm higher than the water surface. This differ-
ence appeared to be associated with a perched water table that developed in the
"cultivated" layer of the clay loam soil due to higher hydraulic conductivity in
cultivated than in the lower soil. Downward movement of relatively concentrated
salt solution near the band, due to its greater density, was a factor that allowed
fertilizer bands at lower levels to enter the mainstream of the leaching water.
75:020-107
A HYDRAULICALLY DRIVEN SOIL AUGER FOR SAMPLING FINE-TEXTURED AND WET SOILS,
Byrnes, B.H.
Remote Sensing Institute, South Dakota State University, Brookings, 57006.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 156, January-Febru-
ary 1975. 1 fig, 1 ref.
Descriptors: Soil tests, Soil investigations, Soils, Equipment.
A core-type bucket auger was modified to fit the drive bar of a hydraulic soil
probe with a rotor head. This auger satisfactorily samples claypan, fine-textured
and moderately fine-textured soils in a wet condition. The auger system can readi-
ly be used alternately with tube core samplers.
75:02G-108
A TECHNIQUE FOR INSTALLING INDUCTION COILS IN A PROFILE WITH MINIMUM SOIL DISTUR-
BANCE,
Spotts, J.W., Brown, K.W.
Environmental Effects Laboratory, United States Army Engineer Waterways Experiment
Station, Wicksburg, MS 37180.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 1006-1007,
September-October 1975. 4 fig.
Descriptors: *Soil mechanics. Soil investigations, Soil tests. Soil properties,
Soil engineering.
Details of a technique are given which can be used to position induction coils
in an undisturbed soil profile to study the shrinking and swelling within the soil
profile with changing moisture content. The specially designed apparatus consists
of a soil cutting blade which can be advanced horizontally from an access hole in-
to the soil at the desired depth. The induction coils are installed in the slots
after the holes have been cut. Installations have been made successfully at depths
as great as 2 m.
75:026-109
A COMPACTION APPARATUS FOR THE PREPARATION OF SOIL CORES OF DIFFERENT BULK DENSI-
TIES AND THICKNESSES,
Baligar, V.C., Nash, V.E., Shuman, F.L. Jr.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 1002-1003, Septem-
ber-October 1975. 2 fig, 1 tab, 7 ref.
Descriptors: *Bulk density, *Moisture tension, Root development, Soil tests,
Soil investigations, Laboratory equipment, Laboratory tests.
The apparatus reported herein enables one to prepare soil cores with a desirable
bulk density and having different thicknesses for use in soil compaction and plant
growth studies.
75:02G-110
SIMULATION OF ROOT-ZONE WATER AND DEEP SEEPAGE TO A WATER TABLE,
King, T.G., Lambert, J.R.
66
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Connell/Metcalf & Eddy, Coral Gables, Florida.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975. Chicago, Illinois. 12 p, 5 fig, 2 ref.
Descriptors: *Model studies, *Root zone, Moisture tension, Soil water, Soil
water movement, Seepage, Water table, Evapotranspiration.
The primary objective of this investigation was to develop a computer model that
would simulate the quantity and movement of water in the deep seepage region, i e ,
between the root zone and the water table. Effort was also directed towards
simulating evapotranspiration and the movement of the water table. The model has
been structured so that it may readily be modified to other locations where basic
meteorological records and soil data are available.
75:020-111
EFFECTS OF PHOSPHORUS ON SOME PHYSICAL AND CHEMICAL PROPERTIES OF CLAYS,
Lutz, J.F., Hague, I.
Lyallpur University, Lyallpur, West Pakistan.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 33-36, January-
February 1975. 2 fig, 5 tab, 17 ref.
Descriptors: *Clays, *Phosphorus, Soils, Soil investigations, Soil chemistry.
Montmorillonite, kaolinite, and a 1:1 mixture of them were treated with phosphorus
at rates as high as 1,600 ppm using phosphoric acid and monocalcium phosphate.
After 3 months the clays were examined for pH, zeta potential (charge) , swelling,
hydration in suspension, modulus of rupture of briquets, and water retention at
5 and 15 bars pressure.
75:02G-112
SUPERSATURATION PHENOMENA AND THE FORMATION OF FLUORAPATITE IN AQUEOUS SUSPENSIONS
OF PHOSPHATE ROCK,
Chien, S.H., Wier, D.R., Black, C.A.
Washington University, St. Louis, Missouri
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 43-47, January-
February 1975. 1 fig, 4 tab, 14 ref.
Descriptors: *Acids, *Rocks, Rock properties. Soil investigations.
Dilute HC1 solutions equilibrated with Florida phosphate rock and Tennessee brown
phosphate rock in the presence of solid fluorite developed a condition of super-
saturation with respect to fluorapatite at 25C. In suspensions boiled before
equilibration at 25C, however, the solutions were in equilibrium with fluorapatite,
as evidenced by ion-activity products for fluorapatite in the solutions.
75:02G-113
BONDING OF CALCIUM AND POTASSIUM BY VERMICULITE AND KAOLINITE CLAYS AS AFFECTED
BY H-CLAY ADDITION,
Baweja, A.S., McLean, E.O.
Ohio State University, Columbus, OH 43210
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 48-50, January-
February 1975. 2 fig, 1 tab, 16 ref.
Descriptors: *Kaolinite, *Calcium, *Potassium, Soils, Soil investigations.
The less than 2 micro-m fraction of Libby vermiculite and Peerless kaolinite was
separated and H-saturated by resin treatment. The H-clay suspensions were immedi-
ately saturated with either Ca or K by addition of the respective hydroxides.
Six reciprocal Ca-K saturations of each clay were prepared by mixing the Ca-and
K-clays in appropriate amounts. Increments of H-clay were added to lower the base
saturation and thereby inactivate the pH-dependent charges.
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75:02G-114
YIELD RESPONSE OF ALFALFA CULTIVARS AND CLONES TO SEVERAL pH LEVELS IN TATUM SUB-
SOIL,
Buss, G.R., Lutz, J.A. Jr., Hawkins, G.W.
Virginia Polytechnic Institute and State University, Blacksburg, VA. Agronomy
Department.
Agronomy Journal, Vol. 67, No. 3, p 331-334, May-June 1975. 5 tab, 8 ref.
Descriptors: *Aluminum, *Alfalfa, Crop response, Subsoil, Soil investigations,
Soil tests.
Breeding for increased tolerance to high aluminum-low pH soils should enlarge the
range of adaptation of alfalfa. This research was undertaken to obtain information
on the range of genetic variation present in alfalfa cultivars for reaction to soil
pH in a high aluminum soil. Eighteen alfalfa cultivars were planted in unlimed
(pH 4.4) and limed (pH 6.0) Tatum subsoil. None survived in the unlimed soil and
all grew in the limed soil. Clones were selected for root development in unlimed
soil after growing down through a 5 cm layer of limed soil. When grown at pH levels
of 5.3, 6.1, and 7.5, they showed a highly significant clone X pH interaction for
yield. However, on the average they did not seem much more acid tolerant than un-
selected clones. This screening technique was somewhat successful in isolating
acid tolerant clones, but forage yield at low pH appeared to be a better criterion.
Our results indicate that alfalfa cultivars exhibit a narrower range of acid toler-
ance than is known to exist in several other crop species, but that individual
clones differ in their reaction to both low and high soil pH.
75:020-115
INTERACTIONS OF MICRONUTRIENTS IN' BARLEY GROWN ON ZINC-POLLUTED SOILS,
Singh, B.R., Steenberg, K.
H.P. University, Palampur, 176061 H.P. India.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 674-679, July-
August. 1975. 2 fig, 7 tab, 41 ref.
Descriptors: *Nutrients, *Barley, *Zinc, Soil tests. Soil investigations, Crop
response. Pollution.
Barley grown in zinc-polluted soils with variable levels of Zn, Mn, and Fe showed
no marked differences in the yield attributable to these variables in both soils
investigated. However, in direct contrast to results reported by other investiga-
tors, concentrations of 65Zn and total zinc were found to increase with increased
levels of added Mn and/or Fe with few exceptions. Similarly, concentrations of
54Mn and total Mn also increased with increased levels of Zn and/or Fe. The
effects of Zn and Mn on the concentrations of 59Fe and total Fe were inconsistent.
The concentration of Mo was found to decrease with increased levels of Zn, Mn, and
Fe and the decrease was more pronounced in one soil than in the other.
75:02G-116
EFFECT OF DEGREE OF SOIL PROFILE DISRUPTION ON PLANT GROWTH AND SOIL WATER EXTRAC-
TION,
Rakov, K., Eck, H.V.
N Poushkarov Institute of Soil Science, Sofia, Bulgaria.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 744-746, July-
August 1975. 3 fig, 3 tab, 9 ref.
Descriptors: *Soil profiles, *Infiltration, Soil investigations, Soil environment,
Soil water, Soil horizons.
Modification of slowly permeable soil profiles has been effective in ameliorating
undesirable soil conditions. Various methods and depths of modification have been
studied but little attention has been given to (i) the degree of disruption neces-
sary to accomplish satisfactory profile modification or (ii) the relative merits
of topsoil-subsoil mixing and stockpiling and returning topsoil to the surface
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after profile modification. We studied seven degrees of profile disruption (clod
size distributions in the B22t and mixing of topsoil with that horizon) in simula-
ted soil profiles in the greenhouse. Grain sorghum was grown on Pullman clay loam.
Disturbance of the B22t layer increased yields but once that layer was disturbed,
degree of disturbance had no further effect on yield. Compared with retaining top-
soil on the surface, mixing it with the B22t did not affect yields.
75:02G-117
SOIL CHANGES RESULTING FROM CROPPING,
Skidmore, E.L., Carstenson, W.A., Banbury, E.E.
United States Department of Agriculture, Agricultural Research Service, Manhattan,
Kansas.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 964-967, September-
October 1975. 3 fig, 2 tab, 24 ref.
Descriptors: *Crops, Crop production, Soil investigations, Soil properties, Grass-
es, pastures, Soil structure, Organic matter.
The need to document further the changes in soil properties from various cropping
systems and the uniqueness of a long-time cultivated field adjacent to buffalograss
pasture prompted us to evaluate soil-property changes of a Keith silt loam charac-
teristic of that pasture and field. In the fall of 1973, we broke the sod of the
buffalograss pasture for analysis. Soil samples were obtained from the pasture
(newly broken sod) and the adjacent cultivated field. The wet aggregates from the
pasture were stabler as compared with the cultivated field for both flash and
vacuum wetting. However, the dry aggregates from the cultivated field were slight-
ly stabler than those from the pasture.
75:02G-118
A THERMODYNAMIC MODEL FOR PREDICTING THE FORMATION, STABILITY, AND WEATHERING OF
COMMON SOIL MINERALS,
Rai, D., Lindsay, W.L.
Batelle Northwest, Box 999, Richland, Washington 99352.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 991-996, September-
October 1975. 5 fig, 2 tab, 6 egu, 33 ref.
Descriptors: *Model studies, *Weathering, Soils, Soil investigations.
Numerous workers have examined the weathering products of soil minerals and have
proposed empirical weathering sequences. The present paper outlines the develop-
ment of a thermodynamic model that predicts in a systematic way several mineral
transformations that can occur in soils. According to this model, the stability of
primary minerals increases in the order: Na-glass, K-glass, pyroxene, analcime,
anorthite, low albite, muscovite, microcline, and quartz. The stability of secon-
dary clay minerals depends on soluble silica. At pH 6 with high silica the order
of increasing stability is: chlorite, halloysite, gibbsite, illite, dickite,
beidellite, kaolinite, and montmorillonite; at low silica the order is: chlorite,
halloysite, illite, beidellite, montmorillonite, dickite, kaolinite, and gibbsite.
The stability of both primary and secondary minerals increases with pH.
75:02G-119
TRANSPORT OF WATER AND HEAT IN A FROZEN PERMEAMETER,
Miller R D., Loch, J.P.G., Bresler, E.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1029-1036, Novem-
ber-December 1975. 4 fig, 1 tab, 48 equ, 16 ref.
Descriptors: *Frozen ground, *Frozen soils, Soil water, Soil water movement,
Model studies, Permeameters, -Soil properties.
Transport of water in frozen soils is probably not restricted to fluid phases.
in a frozen permeameter a series-parallel mode of transport should exist in which
the ice phase may move with uniform translational velocity in a stationary pore
system formed by particles having adsorbed films of unfrozen water. A microscopic
69
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model for coupled mass and heat transport would be complex, but foundations for
such a model are laid in an exercise which derives direct and cross coefficients
for coupled transport equations applicable to a permeameter containing a simplified
(nontortuous) "soil" with uniform cylindrical channels, ice-filled except for films
adsorbed at channel walls. Temperature dependence of coefficients, assuming
Newtonian shear in the film, can be modeled using standard double-layer theory.
75:020-120
CHANGES IN THE PHYSICAL PROPERTIES OF SOIL CLAYS DUE TO PRECIPITATED ALUMINUM AND
IRON HYDROXIDES: I. SWELLING AND AGGREGATE STABILITY AFTER DRYING,
El-Swaify, S.A., Emerson, W.W.
Department of Agronomy and Soil Science, University of Hawaii, Honolulu 96822.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1056-1063, November-
December 1975. 5 fig, 4 tab, 25 ref.
Descriptors: Soils, Soil properties, Soil investigations, Aluminum, Iron, Soil
chemistry, Soil chemical properties.
Compressed discs of an illite, a kaolinite, and a mixture of the two were formed
from freeze-dried dispersed suspensions of the clays, into which one level of
Fe(OH)3 and two levels of A1(OH}3 had been precipitated. The precipitated Fe was
found to consist of particles about 40A in diameter and amorphous to X-ray, rather
than the acicular goethite that precipitates under similar conditions in the
absence of clay. It was deduced from N2 and water vapor sorption measurements
that the precipitated Al was present as very thin layers on the surface of the
clay particles, which in the case of the illite could bridge some of the particles.
Their form was generally indeterminate, in contrast to the well-crystallized
bayerite formed in the absence of clay.
75:02G-021
THE USE OF A SPECIFIC ION ELECTRODE FOR DETERMINATION OF BROMIDE IN SOILS,
Onken, A.B., Hargrove, R.S., Wendt, C.W., Wilke, O.C.
Texas Agricultural Experiment Station, Texas A&M University, Agricultural Research
and Extension Center, Lubbock, Texas.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1223-1225, November-
December 1975. 3 tab, 2 equ, 9 ref.
Descriptors: *Bromides, *Electrodes, *Tracers, Soil tests, Soil investigations,
Chloride, Anions.
Bromide has desirable characteristics for use as a- tracer for NO3- in some soil
studies. However, its quantitative determination in the presence of C1-, which
occurs in interfering quantities in many soils, requires lengthy procedures.
Further, Br- interferes with the quantitative determination of Cl- for which con-
centrations may also need to be determined. To facilitate the use of Br- as a
tracer in such tests, a procedure for the rapid and accurate determination of wa-
ter-extractable Br- in the presence of Cl- and Cl- in the presence of Br- was
developed. These quantitative determinations over a wide range of concentrations
were accomplished by use of standard curves, interference curves, and successive
approximations. Bromide added to soil over a wide range of concentrations was
quantitatively recovered.
75:02G-122
A MODEL FOR THE SIMULTANEOUS PRODUCTION AND DIFFUSION OF FERROUS IRON IN SUBMERGED
SOILS,
Harmsen, K., Van Breemen, N.
Department of Soils and Fertilizers, Agricultural University, P.O. Box 37, Wagenin-
gen, The Netherlands.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1063-1068, November-
December 1975. 4 fig, 14 equ, 19 ref.
Descriptors: *Model studies, *Iron, *Saturated soils, Soil horizons, Soils, Soil
investigations, Rice.
70
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The model describes the distribution of dissolved ferrous iron as a function of
time and depth in a flooded soil profile consisting of three distinct horizons.
In this soil profile, the production of dissolved ferrous iron is high and constant
with depth in the surface horizon, low and constant with depth in the subsoil, and
varies linearly with depth between these two values in the intermediate horizon.
The Fe2+ concentration is found as the difference of the rate of ferrous iron
production, integrated over time and a diffusion term consisting of an infinite
series of the third and fifth repeated integral of the complementary error function.
The parameters considered are (i) three constants specifying the dependence of the
ferrous iron formation on time and depth, (ii) the depths of the three horizons,
and (111) the apparent diffusion coefficient. As shown by one example, the
general solution can be greatly simplified for many cases of practical interest.
The inherent assumptions of the model and its application to actual water-logged
soils are discussed.
75:02G-123
SOIL POTASSIUM RELATIONSHIPS AS INDICATED BY SOLUTION EQUILIBRATIONS AND PLANT
UPTAKE,
Munn, D.A., McLean, E.G.
Department of Agronomy, Ohio State University.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1072-1076,
November-December 1975. 2 fig, 7 tab, 17 ref.
Descriptors: *Potassium, *Corn, *Ohio, Soils, Soil investigations, Soil chemistry,
Nutrients, Fertilizer, Fertilization.
Four Ohio soils of wide range in K release capability were initially K-treated and
successively cropped three times with corn in a growth chamber. Aliguots of the
soils with and without K added and before and after cropping were assayed by extrac-
tion, equilibration, and plant uptake techniques for the effects of crqpping and
K-treatment. Uptake of K by the corn was closely related to the K release capa-
bilities of the soils. Exchangeable K increased as rate of K increased. Initial
cropping decreased the exchangeable K in all soils eliminating the effect of K
treatments on exchangeable K. However, after initial cropping where no K was
added, exchangeable K varied sixfold from the lowest to the highest.
75:02G-124
NITRATE-NITROGEN REMOVAL FROM SOIL PROFILES BY ALFALFA,
Mathers, A.C., Stewart, B.A., Blair, B.
USDA, and Texas A&M University, Soil, WAter and Air Sciences, Southern Region,
Agricultural Research Service.
Journal of Environmental Quality, Vol. 4, No. 3, 1975. p 403-405, 3 fig, 3 tab,
12 ref.
Descriptors: *Nitrate, *Nitrogen, *Alfalfa, Crop response, Crop production, Phos-
phorus, Soil investigations, Soil profiles.
Alfalfa was established in the fall of 1971 on plots previously treated with o,
22, 45, 112, or 224 metric tons/ha of manure annually for 3 years. Additional
plots had received 224 kg N/ha annually for 3 years. Nitrate-nitrogen and water
contents of the soil profile were determined by 30-cm increments to 6 m prior to
planting. Nitrate-nitrogen was found to 6 m, but the largest concentrations were
in the top 1.8 m, where amounts of N03(-)-N varied from 100 to 2,400 kg/ha. Addi-
tional profile samples were taken in 1972 and 1973 after the final cutting of al-
falfa. The data showed that alfalfa removed water and N03(-)-N to a 1.8-m depth
the first year and to 3.6 m the second year. These results indicate that alfalfa
could remove NO3(-)-N from the lower depth of soil profiles where annual crops
were not effective. Yield, NO3(-)-N, and P contents of alfalfa were increased by
manure. Total N taken up by the crop was directly related to the yield.
A5DEVICE2FOR ISOLATING FIELD SOIL COLUMNS WITH MINIMUM DISTURBANCE,
Soiinand'crop Sciences Department, College Station, Texas 77843.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1008-1009,
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November-December 1975. 2 fig, 2 ref.
Descriptors: Soil investigations, Lysimeters, Soil tests.
A device is described which can be used to dig a ditch to isolate soil blocks
in the field. The ditch can be as deep as 1.5 m with a width of 2.5 cm thus
minimizing the amount of soil disturbance in individual blocks. The necessary
equipment can be fabricated in a well equipped shop with a minimum of expense.
75:02G-126
DENITRIFICATION IN SUBSOILS OF THE NORTH CAROLINA COASTAL PLAIN AS AFFECTED BY
SOIL DRAINAGE,
Gambrell, R.P., Gilliam, J.W., Weed, S.B.
North Carolina Agricultural Experiment Station, Raleigh, NC
Journal of Environmental Quality, Vol. 4, No. 3, 1975, p 311-316, 5 fig, 1 tab,
32 ref.
Descriptors: *Denitrification, Nitrogen, Nitrogen cycle, Subsoil, North Carolina,
Drainage, Drainage effects, Soil investigations.
In a tiled moderately well-drained soil, over 200 kg N03-N/ha were generally found
distributed throughout the top 3 m. However, in a poorly drained soil, relatively
low levels of NO3 were found in the top m and very little N03 persisted in the
saturated zone beneath 1 m. Oxidation-reduction potential (Eh) measurements in the
tiled moderately well-drained soil indicated well-oxidized conditions to 3 m. The
Eh measurements beneath 1 m in the poorly drained soil consistently indicated
favorable conditions for denitrification. A marked decrease in the N03-N/C1 ratio
with depth in the poorly drained soil consistently indicated favorable conditions
for denitrification. A marked decrease in the NO3-N/C1 ratio with depth in the
poorly drained soil supported the contention thati denitrification was occurring
in the soil.
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Section VIII
WATER CYCLE
LAKES (GROUP 02H)
75:02H-001
GEOCHEMISTRY AND NATURAL IONIC AND ISOTOPIC TRACING: TWO COMPLEMENTARY WAYS TO
STUDY THE NATURAL SALINITY REGIME OF THE HYDROLOGICAL SYSTEM OF LAKE CHAD,
Roche, M-A.
Office de la Recherche Scientifique et Technique Outre-Mer, Paris (France). Hy-
drology Section.
Journal of Hydrology, Vol. 26, No. 1/2, p 153-171, July 1975. 7 fig, 1 tab, 28 ref.
Descriptors: *Lake basins, *Hydrologic systems, *Water chemistry, *Isotope studies,
*Saline lakes, Groundwater, Geochemistry, Lakes, Lake sediments, Salinity, Ions,
Chemical analysis, Cations, Chromatography-
As a consequence of intense evaporation and transit through a succession of sedi-
mentary traps (flood plains, lake, dune aquifer, and interdune depression), the
isotopic composition and the characteristics of the dissolved and suspended loads
of Lake Chad water change downstream in a regular manner resembling chromatography-
The migration of the water and chemical constituents from one end to the other of
this endorheic basin, extending from the humid tropics to the desert margins,
was outlined and quantified. The erosion, transport, and sedimentation phenomena
and the natural saline and isotope tracing methods were studied simultaneously.
It was illustrated that these two avenues of research are complementary, justify-
ing the use of common models, and are indispensable to each other.
75:02H-002
EFFECTS OF WATERHYACINTH COVER ON WATER CHEMISTRY, PHYTOPLANKTON, AND FISH IN
PONDS,
McVea, C., Boyd, C.E.
Southern Region, Agricultural Research Service, United States Department of
Agriculture and the Louisiana Agriculture Experiment Station, Baton Rouge.
Journal of Environmental Quality, Vol. 4, No. 3, 1975. p 375-402, 5 tab, 27
ref.
Descriptors: *Water hyacinth, *Aquatic life, *Water chemistry, *Aquatic weeds,
Water quality, Fish, Ponds, Pondweeds, Phosphorus.
Water hyacinth cover of 0, 5, 10, or 25% surface was established in fertilized
ponds stocked with the fish, Tilapia aurea, at Auburn, Alabama. Measurements of
water chemistry, phytoplankton density, and fish production were made during the
1973 growing season. Phytoplankton production was less in ponds with 10 and 25%
cover by waterhyacinth than in ponds with 0 and 5% cover. Competition of water-
hyacinth with phytoplankton involved shading and removal of phosphorus from the
water. Concentrations of dissolved oxygen were lowest in ponds with 25% cover,
but oxygen tensions in all ponds were adequate for survival and growth of fish.
Reduction in phytoplankton growth in ponds with 10 and 25% cover resulted in much
lower fish production. The presence of 5% cover by waterhyacinth did not signifi-
cantly affect fish production.
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Section IX
WATER CYCLE
WATER IN PLANTS (GROUP 021)
75:021-001
SALT TOLERANCE AND SUITABILITY OF VARIOUS GRASSES FOR SALINE ROADSIDES,
Hughes, T.D., Butler, J.D., Sanks, G.D.
Turfgrass extention, Colorado State University, Fort Collins, Colorado 80523
Journal of Environmental Quality, Vol. 4, No. 1, p 65-68, January-March 1975.
1 fig, 6 tab, 12 ref.
Descriptors: *Salinity, *Crop response, *Saline soils, *Grasses, *Salt tolerance.
Forage yields of five species were studies in soil under greenhouse conditions
with NaCl additions of 0; 5,000; 10,000; and 20,000 ppm. Forage yield of p.
distans was reduced 23% by addition of 20,000 ppm NaCl, compared to a minimum
reduction of 40% for the other grass species. Mineral analysis of leaf tissue
by emission spectroscopy showed that Na concentrations increased as NaCl addition
to the soil increased. However, there was no relationship between salt tolerance
of the various grasses and amounts of Na in leaf tissue. Increased NaCl addition
to the soil resulted in decreased leaf Ca and Mg, but no relationship existed
between leaf K and NaCl addition.
75:021-002
LEAF PHOTOSYNTHESIS: THE INFLUENCE OF ENVIRONMENTAL VARIABLES,
Incropera, F.P.
California University, Berkeley, Department of Mechanical Engineering.
Journal of Environmental Quality, Vol, 4 No. 4, p 440-447, October-December 1975.
13 fig, 35 ref, 1 append.
Descriptors: *Crop response, *Model studies, *Corn, *Photosynthesis, Environmental
effects, Environmental control, Environment.
A model is presented for the effects of light intensity and ambient temperature,
relative humidity, and carbon dioxide concentration on leaf photosynthesis. The
model treats diffusion and chemical processes occurring within the leaf, as well
as the transfer of mass and energy between the leaf and its environment. Calcu-
lations have been performed for Zea mays L. (maize) which suggest the influence
of environmental changes. Although leaf energy exchange processes act to moderate
the effect of changes in the atmospheric temperature, a severe cooling trend may
cause as much as 2C% reduction in photosynthesis. Under most"conditions", the rate
of photosynthesis is further diminished by a reduction in relative humidity- In
contrast, a 20% increase in the atmospheric CO2 concentration, which is projected
for the year 2000, will increase photosynthesis by approximately 15%. The calcu-
lations also suggest optimum ambient conditions for controlled growth.environments,
such as a greenhouse.
75:021-003
LEAF WATER POTENTIAL AND MOISTURE BALANCE—FIELD DATA,
Huck, M.G., Browning, V.D., Young, R.E.
Agricultural Engineering Department, Agricultural Experiment Station, Auburn,
Alabama.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, 15 pages, December 15-18, 1975, Chicago, Illinois. 6 fig, 2 tab, 13
ref.
Descriptors: *Root development, *Root distribution, *Root system, Soil moisture,
Soil water, Soil-water-plant relationships. Irrigation, Irrigation practices,
Transpiration.
(See 75:02G-066 for article)
75:021-004
PLANT WATER STRESS CRITERIA FOR IRRIGATION SCHEDULING,
74
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Stegman, E.G., Schiele, L.H., Bauer, A.
Agricultural Engineering Department, North Dakota State University, Fargo, North
Dakota.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 7 fig, 6 tab, 18 ref.
Descriptors: *Soil water, *Soil moisture, *Soil-water-plant relationships,
Scheduling, Crop response, Plant Physiology, Plant tissues, Stress, Stress analy-
sis, Irrigation, Irrigation effect.
(See 75:02G-067 for article)
75:021-005
DISTRIBUTION OF SALTS IN THE ROOT ZONE,
Raats, P.A.C.
Agricultural Research Service, Riverside, California Salinity Lab.
Journal of Hydrology, Vol. 27, No.'3/4, p 237-248, December 1975. 7 fig, 21 ref.
Descriptors: *Salts, *Root zone, *Distribution, Absorption, Soil water, Soil
profiles, Depth, Salinity, Leaching, Salt balance. Saline water, Convection,
Irrigation, Evaporation, Transpiration, Drainage, Velocity, Travel time, Tensiome-
ters.
Selective uptake of water and convection of salts with the soil water are the
main factors governing the distribution of salts in the soil profile. Depth-time
trajectories of elements of water were calculated as a function of their initial
position, the average soil water content, the uptake distribution, and the rates
of irrigation, evaporation, transpiration, and drainage. The mass balance for the
salt was reduced to a linear, first-order partial differential equation whose
characteristics are the depth-time trajectories of elements of water. Expressions
for the increase in salinity along the trajectories were derived. In all specific
calculations, it was'assumed that the rate of uptake has its maximurti at the soil
surface and decreases exponentially with depth. As illustrations, calculations
were made of depth-time trajectories of elements of water, steady and transient
salinity profiles, and the responses of salinity sensors at various depths follow-
ing a step increase and a step decrease of the leaching fraction.
75:021-006
CROP STATUS EVALUATIONS AND YIELD PREDICTIONS,
Haun, J.R.
Department of Horticulture, Clemson University, Clemson, S.C.
Annual Summary Report, March 1975. 41 p, 16 fig, 8 tab, 1 append.
Descriptors: *Crop response, *Yield equations, Model studies, Mathematical models,
Wheat.
The work reported herein was based on the program outlined in the reference NASA
Headquarter's Y-001-043. During the course of this work it was decided to extend
the contract to include the remaining portion of the 1974-75 winter wheat season
and to collect data on a second season of both spring and winter wheat.
75:021-007
PRECIPITATION OF CALCIUM AND STRONTIUM SULFATES AROUND PLANT ROOTS AND ITS EVAL-
UATION,
Malzer, G.L., Barber, S.A.
Minnesota University, Minneapolis, 55455.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 492-495, May-June
1975. 2 fig, 2 tab, 8 ref.
Descriptors: *Precipitation, *Calcium, *Strontium, *Sulfates, Root system.
The flux of Ca2+, and SO4(2-) to corn roots was investigated to determine if ac-
cumulation at the root caused precipitates to form and if so to determine the
75
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influence of precipitate formation on Ca and Sr uptake. Autoradiographic tech-
niques using 45Ca and 35S showed both Ca2+ and S04(2-) accumulated at root surfaces
when supply be mass-flow exceeded uptake. Petrographic studies of the roots
confirmed the formation of CaS04 precipitates.
75:021-008
DIURNAL FLUCTUATION OF LEAF-WATER POTENTIAL OF CORN AS INFLUENCED BY SOIL MATRIC
POTENTIAL AND MICROCLIMATE,
Reicosky, D.C., Campbell, R.B., Doty, C.W.
ARS-USDA, Florence, SC 29501.
Agronomy Journal Vol. 67, No. 3, p 380-385, May-June 1975. 4 fig, 1 tab, 21 ref.
Descriptors: *Microclimatology, *Moisture stress, *Moisture tension. Crop response,
Corn, Irrigation, Irrigation effects, Crop production.
Water stress during critical growth periods is frequently the limiting factor in
crop production. However few data are available on the variation of plant water
status under field conditions. The object of this work was to quantify the effect
of soil matric potential on plant water status. Sweet corn was grown on a Varina
sandy loam soil to determine the effect of the microclimate and irrigation on leaf
water potential. Soil water stress was imposed naturally and by use of automated
portable shelters that covered the plots during rainfall. Leaf-water potential
was closely related to the diurnal change of incoming energy. A maximum leaf-
water potential of -1.5 bars occurred just prior to sunrise. The minimum value,
which occurred during the peak radiation load or stress, was dependent on soil
raatric potential and stage of plant development.
75:021-009
CALCULATION OF RATE OF NUTRIENT UPTAKE BY GROWING ROOTS,
Khasawneh, F.E.
Agronomy Journal, Vol. 67, No. 4, p 574-576, July-August 1975. 21 equ, 7 ref.
Descriptors: *Root.development, *Root systems, *Nutrients, *Nutrient removal,
*Fertilizers, Mathematical analysis, Crop response.
Equations are presently available to calculate the rate of nutrient uptake by
growing roots. They can be used to estimate an average rate of uptake by the
entire root system, but they fail to give specific information on uptake by a unit
segment of root or on the effects of aging and morphological changes of such a
segment on its capacity for uptake. This paper gives a theoretical analysis of
the process of nutrient uptake by a growing root'system. The objective of this
analysis is to derive equations that would give such specific information. A
frequency distribution function is used to partition root systems into a continuum
of age groups, each possessing a rate of uptake that is a function of the age of
that group. Equations are derived that utilize time-series measurements of root
length and nutrient accumulation in the plant. These derivations are used to cal-
culate parameters of nutrient uptake related to two properties of the root system;
(i) the rate of nutrient uptake of a unit segment of root and the manner by which
this rate changes with aging and (ii) the rate of nutrient flux into the entire
root system as a function of time.
75:021-010
RESPONSES OF BERMUDAGRASS TO SALINITY,
Ackerson, R.C., Youngner, V.B.
California University, Riverside, CA 92502
Agronomy Journal, Vol. 67, No. 5, p 678-681, September-October 1975. 6 tab, 27
ref.
Descriptors: *Bermudagrass, *Crop response, *Salinity, Turf grasses, Turf, Salt
tolerance.
Bermudagrasses are salt-tolerant grasses valuable for forage and turf. Experi-
ments were conducted to determine specific responses to increasing salinity to
provide a basis for breeding of more salt tolerant, agronomically desirable strains.
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The cultivar "Santa Ana" was grown in solution cultures containing increasing
levels of Nad and CaC12 or K2SO4. Dry weight of tops decreased while dry weight
of roots and total nonstructural carbohydrate concentrations of crowns, but not
roots, increased with increased salinity of the culture solution.
75:021-011
RESISTANCE TO WATER TRANSPORT IN RICE PLANTS,
Tomar, V.S., Ghildyal, B.P.
University of Agriculture & Technology, Pantnagar, Nainital, India.
Agronomy Journal, Vol. 67, No. 2, p 269-272, March-April 1975. 3 fig, 1 tab,
12 ref.
Descriptors: *Rice, *Transpiration, Soil-water-plant relationships, Irrigation,
Irrigation practices.
Rice is grown either in continuously flooded "lowland" soils or under rainfed
conditions in "upland" soils. The objective of the study was to determine whether
there are differences in resistance to water transport between plants grown in
flooded and nonflooded soils. This information may be useful in understanding
the plant-water relations under two cultural practices.
75:021-012
ESTIMATING RELATIVE LEAF WATER CONTENT WITH A SIMPLE BETA GAUGE CALIBRATION,
Obrigewitsch, R.P., Rolston, D.E., Nielsen, D.R., Nakayama, P.S.
Soil Conservation Service, Kalmath Falls, Oregon.
Agronomy Journal, Vol. 67, No. 5, p 729-732, September-October 1975. 3 fig, 8 ref.
Descriptors: *Sugar beets, *Crop response, Moisture, Plant growth, Plant tissues.
Existing methods for periodically measuring plant water status require considerable
instrumentation or time. The method described herein simplifies plant water
measurement by providing a completely linear calibration between attenuated beta
radiation through a plant leaf and its relative water content simply by measuring
the radiation intensity through the leaf at only two water contents - full turgid-
ity and complete dryness.
75:021-013
THE RECOVERY OF LEAF WATER POTENTIAL, TRANSPIRATION, AND PHOTOSYNTHESIS OF COTTON
DURING IRRIGATION CYCLES,
Bielorai, H., Hopmans, P.A.M.-
The Volcani Center, Bet Dagan, Israel.
Agronomy Journal, Vol. 67, No. 5, p 629-632. September-October 1975. 6 fig, 1
tab.
Descriptors: *Moisture stress, *Transpiration, *Photosynthesis, *Cotton, Irriga-
tion, Irrigation effects. Crop response, Crop production, Soil water.
The ability of a plant to recover from temporary and/or prolonged stress and the
rate of recovery are of great importance in crop production. However, the infor-
mation available on this subject is relatively scarce. A study was conducted to
evaluate the recovery of irrigated cotton following soil moisture stress of
various durations through the measurements of soil moisture stress using 1) the
soil-moisture retention function, leaf water potential, by pressure bomb, and 2)
leaf diffusion resistance by diffusive resistance porometer. Photosynthesis was
measured by an infrared gas analyzer, and transpiration by weighing.
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Section X
WATER CYCLE
EROSION AND SEDIMENTATION (GROUP 02J)
75:02J-001
EROSION MODELING ON A WATERSHED,
Onstad, C.A., Foster, G.R.
Agricultural Research Service, Morris, Minnesota. North Central Soil Conservation
Research Center.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 2,
p 288-292, March-April 1975. 2 fig, 3 tab, 7 ref.
Descriptors: *Erosion rates, *Rill erosion, *Model studies, *Soil erosion,
*Sediment yield, Watersheds (Basins), Sediment transport, Mathematical models,
Runoff, Slopes, Sheet erosion, Surface runoff, Storm runoff, Deposition (Sediments),
Iowa, Ohio.
An erosion-deposition model was described based on a modified form of the
Universal Soil Loss Equation incorporating hydrologic variables. The sediment
yield concept and computations involve calculating soil detachment potential
and transport potential on a storm by storm basis and then comparing the two,
resulting in sediment yields and deposition. All computations were made on a
unit width basis and extended to the entire watershed, using an appropriate
watershed transformation scheme. Calculations along the slope length were made
on slope segments, each with different length and steepness. A procedure for
estimating the relative contributions of rill and interrill erosion was also
presented. The final result was an estimate of the rill and interrill erosion
distribution on a watershed, indicating areas of severe erosion and deposition.
The model was used to simulate the soil movement during 11 storms on two Mid-
west watersheds planted to contour corn. Predictions on the 82.8-acre Iowa
watershed were better than those on the smaller 1.5 acre Ohio watershed.
75:02J-002
SIMULATION OF SOIL EROSION-PART I. DEVELOPMENT OF A MATHEMATICAL EROSION MODEL,
David, W.P., Beer, C.E.
International Rice Research Institute, Los Banos, Laguna (Philippines).
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 1,
p 126-133, January-February 1975. 2 fig, 21 ref.
Descriptors: *Soil erosion, *Mathematical models, *Overland flow, *Precipitation
intensity, *Raindrops, *Stream erosion. Sheet erosion, Rill erosion, Runoff,
Suspended solids, Cultivation, Gully erosion, Model studies, Watersheds (Basins),
Equations, Sediment transport, *Simulation analysis.
Results of a study conducted to simulate the process of sheet erosion by water
were described. The primary objective of the study was to develop a mathematical
model of erosion by water. The Kentucky Watershed Model was adopted to generate
values of overland flow to be used in the erosion model. The other input to
the precipitation. Equations expressing soil erosion from stream banks, impervi-
ous surfaces, and raindrop splash were developed. In addition, the carrying
capacity of the overland flow was continuously evaluated to determine whether
soil particles were being removed and transported from storage or deposited. The
equations upon which the mathematical model was based are power functions with
parameters that are to be evaluated during calibration runs of the model.
75:02J-003
SIMULATION OF SOIL EROSION-PART II. STREAMFLOW AND SUSPENDED SEDIMENT SIMULATION
RESULTS,
David, W.P., Beer, C.E.
International Rice Research Institute, Los Banos, Laguna (Philippines).
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 1,
p 130-133, January-February 1975. 2 fig, 3 tab, 8 ref.
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Descriptors: *Simulation analysis, *Soil erosion, "Overland flow, *Precipitation
intensity, *Sheet erosion, Mathematical models, Calibrations, Snowmelt, Suspended
load, Stream erosion, Bank erosion, Scour, Streamflow, *lowa, Model studies.
Watersheds (Basins).
A sheet erosion model was developed to simulate sheet erosion from small agricul-
tural watersheds. The sheet erosion model was used in conjunction with the
Kentucky Watershed Model, which is a modified verison of the Stanford Watershed
Model. The Kentucky Watershed Model was modified and adapted to Iowa conditions.
To evaluate the feasibility of the sheet erosion model, it was tested on the
Four Mile Creek Watershed near Traer, Iowa. The simulated daily, monthly,
and annual suspended sediment loads compared favorably to the observed values.
It was mentioned that the sheet erosion model cannot be applied for large
watersheds. The model also cannot predict the sediment deposition along flood-
plains and it lacks sufficient parameters to define the seasonal effect on some
of the sheet erosion parameters.
75:02J-004
SOIL EROSION AND SEDIMENT TRANSPORT FROM GULLIES,
Piest, R.F., Bradford, J.M., Wyatt, G.M.
Agricultural Research Service, Columbia, Watershed Research Unit.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol. 101,
No. HY1, Proceedings paper 11069, p 65-80, January 1975. 7 fig, 4 tab, 19 ref,
1 append.
Descriptors: *Erosion, *Gullies, *Mass wasting, "Sedimentation, "Tractive
forces, Soil mechanics, Sediment transport, Watersheds (Basins), Soil conserva-
tion, Watershed management, Storm runoff. Hydraulics, *Iowa.
Field observations of four gullied watersheds, 75 acres to 150 acres in size,
showed that gully erosion was one-fifth of the total sediment yield during a 9-yr
period. Erosion rates were dependent upon mass wasting of loessial gully banks
and headcuts. For the nonconservation watersheds, tractive forces exerted by
runoff on the channel boundary did not detach appreciable amounts of undisturbed
soil but were more than adequate to entrain the soil debris yielded by mass-
wasting processes. Gully erosion was minimal on conservation watersheds; the
runoff was generally below the levels required for gully debris removal, and
the degree of slope was reduced to a stable value. Soil mechanics principles,
applied to strength/stability aspects of gully banks in western Iowa, indicated
that the height of the water table, soil cohesive strength, and rate of water
infiltration are controlling factors. Initial field and laboratory model
experiments provided insight into variables that affect the mass-wasting
process. A large part of the gully soil debris accumulates during winter and
early spring and is flushed from the channel with the first spring rainstorms.
The relative quanities are greatly reduced for each subsequent runoff event
during the year.
75:02J-005
FUNDAMENTAL ASPECTS OF EROSION OF COHESIVE SOILS,
Arulanadan, K.
California University, Davis.
Journal of the Hydraulics Division, Vol. 101, No. HY5, p 635-639, May 1975. 4 fig,
1 tab, 11 ref.
Descriptors: "Erosion, "Cohesive soils, Erosion rates.
The influence of soil systems at different dispersed states on the erodibility
and swelling is well demonstrated. The degree of dispersion of the soil as
influenced by mineralogy, amount of clay, SAR, concentration of pore and eroding
fluids have to be considered in evaluating the erosion potentials of soils. For
prediction of erodibility, a tentative relationship between CEC (a value which
varies with or depends on the type of clay) and critical shear stress at a parti-
cular concentration of pore fluid at low and high values of SAR is presented.
Experimental and theoretical investigation of erosion is in progress to obtain a
functional relationship between structural parameters quantified in terms of
electrical properties and erodibility.
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75:02J-006
SOIL DETACHMENT FROM CLODS BY SIMULATED RAIN AND HAIL,
Hagen, L.J., Lyles, L., Dickerson, J.D.
Agricultural Research Service, United States Department of Agriculture, Kansas
State University, Manhattan.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 3,
p 540-543, May-June 1975. 2 fig, 6 tab, 18 ref.
Descriptors: *Rainfall, *Hail, *Rainfall intensity, Erosion, Cloud seeding,
Thunderstorms.
Low energy hailfall, which commonly occurs in thunderstorms, can easily increase
soil detachment from clods by 50 percent; at moderate intensities, it can double
soil detachment over no hail. Increased soil detachment occurs when hail dia-
meter exceeds about 0.75 cm. Hail less than 0.75 cm may slightly damage clods
but it quickly covers the surface arid protects against subsequent rain, wind,
and hail damage. The process of soil detachment is complicated and depends on
size and intensity of hail, windspeed, and surface cover as well as on interactions
among these factors. Both seeding clouds to reduce hail size, if successful, and
maintaining a mulch cover of at least 50 percent could substantially reduce soil
detachment from clods.
75:02J-007
A MODEL FOR RUNOFF OF PESTICIDES FROM SMALL UPLAND WATERSHEDS,
Bruce, R.R., Harper, L.A., Leonard, R.A., Snyder, W.M., Tomas, A.W.
United States Department of Agriculture, Southern Region, Agriculture Research
Service.
Journal of Environmental Quality, Vol. 4, No. 4, p 541-548, October-December
1975. 8 fig, 1 tab, 18 ref.
Descriptors: *Sediment load, *pesticides, *Model studies, *Mathematical models,
Rill erosion, Erosion, Water quality, Sediments.
A mathematical model has been developed describing the rate and quantity of runoff
water from separate rainfall events on a watershed and the rate and quantity of
sediment and pesticides transported. The runoff water is calculated by convolving
an area-characteristic and variable state function to produce a variable response
function which is then convolved with a computed effective rain. Rill and
interrill erosion are conceptually distinguished which allows similar partitioning
of associated pesticides. The sediment contribution from interrill erosion is
a function of rainfall intensity and soil susceptibility to erosion. The rill
erosion is a function of water runoff and the rate of change of water runoff.
The concentrations of pesticides in the runoff are functions of the amount of
runoff, the sediment concentrations derived from rill and interrill erosion, and
the pesticide concentrations in the respective runoff-erosion zones. Experience
with the model in simulating the water, sediment, and pesticide runoff from and
upland Piedmont plain watershed for four summer storms is related. Excellent
simulations were obtained.
75:02J-00§
MEASURING WATER VELOCITY BY ULTRASONIC FLOWMETER,
Schuster, J.C.
Bureau of Reclamation, Denver, Colorado. Hydraulic Engineering, Hydrology Branch,
Division of General Research, Engineering Research Center.
Journal of the Hydraulics Division Vol. 101, No. HY12 p 1503-1516, December 1975.
11 fig, 4 tab, 4 ref, 1 append.
Descriptors: *Erosion, *Infiltration, *Scour, Erosion control. Erosion rates,
Bed load.
Ultrasonic flowmeters can be applied to measuring small and large flows in open-
channel and closed-conduit systems. The accuracy of the measurement depends on
positioning the transducers to measure a true average velocity in either open
or closed-conduit flow. A measurement of +2% accuracy may be obtained by applying
a correction factor to the velocity measurement from a single pair of transducers
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in a pipe having a fully developed turbulent velocity destribution. Possibly
four pairs of transducers or a traversing pair are required for accurate measure-
ments in a conduit or channel with unsymmetrical distribution. The metering
method can be applied to flows varying over a wide range in open channels, to
systems designed for a minimum head loss (such as power and pumping plants) , to
large-capacity turnouts that may require multiple venturi meters to measure the
flow range, and to systems having main supplies controlled by requiring electri-
cal power should also consider the cost of supplying the power in evaluating the
meters.
75:02J-009
LOCAL EROSION CAUSED BY RAPID FORCED INFILTRATION,
Willetts, B.B., Drossos, M.E.
Aberdeen University, Aberdeen, Scotland, Engineering.
Journal of the Hydraulics Division, Vol. 101, No. HY12, p 1477-1488, December
1975. 6 fig, 8 ref, 2 append.
Descriptors: *Erosion, *Infiltration, *Scour, Erosion Control, Erosion rates,
Bed load.
Experiments were made in a 76-mm wide flume with a suction zone 76 mm by 125 mm
in the base. In each run, the base of the flume, including the suction zone, was
covered to a depth of 15 mm with grains of reasonably uniform size (as obtained
by sieving) and a sufficient flow of water was introduced to transport bed load.
Water was simultaneously extracted in the suction zone at a rate corresponding
to 5%, 7.5%, 10%, and 12.5% of the'streamflow ^rate upstream. Typically, a bed
feature began to form in and beyond the suction zone, and each run continued
until the feature attained a stable shape and size. Suction and streamflows were
then stopped and the size of the bed feature measured.
75:02J-010
EFFECT OF FLOW RATE AND CANOPY ON RILL EROSION,
Meyer, L.D., Foster, G.R., Nikolov, S.
United States Department of Agriculture, Agricultural Research Service, Oxford, MS
Transactions of the American Society of Agricultural Engineers, Vol. 18 No. 5,
p 905-911, September-October 1975. 7 fig, 3 tab, 18 ref.
Descriptors: *Rill erosion, Erosion, *Flow rate, Return flow, Erosion control,
Canopy, Runo f f.
Field studies were conducted to study the influence of flow rate on rill erosion.
The data suggested that rill erosion does not begin until flow reaches a critical
rate, and equations incorporating this concept were fitted to the experimental
data. Observations and further analyses indicated that rill erosion might be
separated into rill shear and rill headcut components with separate terms for each.
Relationships using independently evaluated rill and interrill erosion components
were compared with the relationship used for the slope-length factor in the
Universal Soil Loss Equation. They agreed quite well for slope lengths up to
about 45 m but diverged considerably at greater lengths.
75:02J-011
CONTROLLING RESERVOIR TRAP EFFICIENCY,
Rausch, D.L., Heinemann, H.G.
United States Deaprtment of Agriculture, Columbia, MO. Agriculture Research
Service, Watershed Research Unit, North Central Region.
Transactions:of the American Society of Agriculture Engineers, Vol. 18 No. 6, p
1105-1108, 1113, November-December 1975. 5 fig, 2 tab, 5 ref.
Descriptors: *Reservoirs, *Sedimentation, Runoff, Reservoir design, Reservoir
operation, Reservoir releases, Water quality, Reservoir silting.
81
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Research on three reservoirs in central Missouri has shown that reservoir sedimen-
tation trap efficiency is affected by the detention time of storm runoff and by
factors governing sediment particle size. Decreasing the detention time can be
done by discharging storm runoff from the reservoir with the use of a bottom-
withdrawal spillway. With the bottom-withdrawal spillway, the clean water remains
in the reservoir and floats above the density currents caused by storm runoff
moving to the deepest part of the reservoir.
75:02J-012
A STOCHASTIC MODEL OF DISPERSION OF SEDIMENT PARTICLES RELEASED FROM A CONTINU-
OUS SOURCE,
Todorovic, P.
Montreal University (Quebec). Department of Mathematics.
Water Resources Research, Vol. 11, No. 6, p 919-925, December 1975. 4 fig,
14 ref.
Descriptors: *Dispersion, *Stochastic processes, *Sediment transport, *Sedi-
ment discharge, *Sediment distribution, *Distribution patterns, Flow, Flow profiles.
Sediments, Bed load, Suspended solids, Suspended load, Sediment load, Convection,
Movement, Water pollution, Water pollution sources, *Path of pollutants, Mathe-
matical studies, Statistical models.
The process of dispersion of bed sediment in streams has become a target for
study because sediment may act as both a pollutant and a vehicle for soluble pol-
lutants. Previous mathematical models of longitudinal dispersion of bed sediment
described the behavior of a quantity of particles released simultaneously from
a point or line source. The proposed model described the more common case of
longitudinal dispersion of a quantity of sediment released gradually, at a known
rate, during a specified time interval. Cases were examined for continuous
release throughout finite and open-ended time intervals. Provided that certain
regularity conditions hold, dispersion models may be obtained for both cases by
simple integral transformation of the model for instantaneous release.
75:02J-013
PHYSICAL-CHEMICAL COMPOSITION OF ERODED SOIL,
Monke, E.J., Marelli, H.J., Meyer, L.D., DeJong, J.F.
Agricultural Engineering Department, Purdue University, West Lafayette, Indiana.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 11 p, 3 fig, 5 tab, 7 ref.
Descriptors: *Runoff *Particle size, *Erosion, *Erosion rates, Soil tests, Soil
investigations, Soil erosion, Soil properties.
Water loss by runoff, soil loss in runoff, particle size distribution in the
eroded soil material, and the water quality of runoff containing eroded soil ma-
terials were measured from soil surfaces subjected to simulated rainfall. Three
soils from the Maumee River Basin under two extreme tilth conditions were selected.
75:02J-014
CONSERVATION OF SEDIMENT IN IRRIGATION RUNOFF,
Robbins, C.W., Carter, D.L.
Snake River Conservation Research Center, Agricultural Research Service, U.S.D.A.,
Kimberly, Idaho 83341.
Journal of Soil and Water Conservation, Vol. 30, No. 3, p 134-135, May-June 1975.
3 fig.
Descriptors: *Return flow, *Irrigation, *Irrigation effects, *Sediments, Sediment
control.
Controlling sediment entering natural streams in irrigation return flow is a ma-
jor economic and ecological challenge. A landowner often has little control over
the management practices of his upstream neighbors. But he may be able to use
sediment from runoff draining onto his land to improve the land's topography. In
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so doing he may reduce erosion on his land and simultaneously lower the downstream
sediment load.
75:02J-015
EROSION IN 1973-74: THE RECORD AND THE CHALLENGE,
Grant, K.E.
Soil Conservation Service, U.S.D.A., Washington, D.C. 20250.
Journal of Soil and Water Conservation, Vol. 30, No. 1, p 29-32. January-February,
Descriptors: *Erosion, *Crop production, *Agriculture, *Soil conservation.
The 1973-74 growing season in many ways was not a good one for the nation's soil
and water resources. Excessive soil erosion from both wind and water accompanied
the efforts of many farmers to increase crop production. Contributing to the
year's poor record was some of the worst weather in years. But severe erosion
could also be traced to the unwise selection of certain soils for cultivated crops
as well as the existence of too few conservation measures on the land.
75:02J-016
IOWA'S EXPERIENCE WITH A MANDATORY SEDIMENT CONTROL LAW,
Greiner, W.H.
Iowa Department of Soil Conservation, Des Moines 50319.
Journal of Soil and Water Conservation, Vol. 30, No. 3, May-June 1975. p 132-134.
Descriptors: *Sediment control, *Sediments, *Legislation, Iowa, Erosion, Erosion
control, Soil erosion.
Before the mid-1960s, sediment control laws were seldom a topic of conversation
in Iowa, but a chain of events took place that brought these words into prominence.
Iowa was one of the first states to enact a sediment control law. Many people
refer to the law as landmark legislation because no other state has a law that
deals with soil erosion to the extent this one does. The law surely has had an
impact on conservation district programs in Iowa, but it is in no sense a model
law. Compromises preceded its enactment. As a result, some sections of the law
are not as strong as they could be.
75:02J-017
A COMPARISON OF NITROGEN, PHOSPHORUS, AND CARBON IN SEDIMENTS AND SOILS OF
CULTIVATED AND NONCULTIVATED WATERSHEDS IN THE NORTH CENTRAL STATES,
Ritchie, J.C., Gill, A.C., McHenry, J.R.
USDA, Sedimentation Laboratory, Alabama-North Mississippi Area in Cooperation
with Mississippi University-
Journal of Environmental Quality, Vol. 4, No. 3, 1975. p 339-341, 5 tab, 12 ref.
Descriptors: *Nitrogen, *Phosphorus, *Carbon, *Return flow, Water quality.
Sediments, Nutrients, Nutrient removal, Cultivation, Cultivated lands, Watersheds
(Basins).
Soil and sediments from six cultivated watersheds and from six noncultivated
watersheds were sampled and the concentration of nitrogen, phosphorus, and carbon
was determined. No significant difference was found in the concentration of N,
P, or C with depth in the soils or sediments. Concentration of N, P, and C were
not significantly different in the soils and sediments of the cultivated water-
sheds; however, the sediments of the noncultivated watersheds had significantly
less N and organic P than the watershed soils. Less accumulation of N, P, and C
is occurring in the noncultivated watershed sediments than in the cultivated
watershed sediments. These data indicate that sediment source is probably an
important factor in determining N, P, and C concentration in reservoir sediments.
75:02J-018
EVALUATION OF AGRICULTURAL POLICY ALTERNATIVES TO CONTROL SEDIMENTATION,
Seitz, W.D., Sands, M.B., Spitze, R.G.F.
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Department of Agricultual Economics, Illinois University, at Urbana-Champaign,
Illinois.
Final Report to the Office of Water Research and Technology, U.S. Department of
the Interior, February 1975. Washington, D.C. Report No. 99. Ill p, 10 fig,
28 tab, 57 ref.
Descriptors: *Erosion, *Sedimentation, *Linear programming, Crop production, Soil
conservation, Soil erosion, Sediments.
Alternative policies for reducing the level of erosion and sedimentation are
evaluated with a linear programming analysis of farms in a selected watershed.
Three conservation practices and three tillage practices are considered in combi-
nation with six crop rotations on approximations of nine actual farms located in
representative sections of the watershed. The impact of these practices on crop
production costs and yields is considered, as is the impact on the off-site damages
to the drainage system and the reservoir. Policies considered include subsidiza-
tion of the cost of adopting conservation practices and subsidies to induce re-
moving land from production, several forms of regulations and an effluent tax.
Where appropriate the policies were analyzed assuming implementation at both the
watershed and the farm level. This analysis indicates that soil conservation
practices should be increased substantially in order to reduce the gross soil loss
in the watershed from over 20 to approximately 6 tons per acre per year. This
reduction is most efficiently accomplished by modifying conservation practices,
tillage practices, and crop rotations. An important finding is the indication
that several alternative policies can be applied at either the watershed or the
farm level and without regard to the farms' proximity to the reservoir, with very
little difference in results.
75:02J-019
A SUBMODEL FOR NITROGEN RELEASE FROM SEDIMENTS,
Jacobsen, O.S., Jorgensen, S.E.
Ferskvandsbiologisk Laboratorium, Helsingorgade, Hillerod (Denmark).
Ecological Modelling, Vol. 1, No. 2, p 147-151, July 1975. 1 fig, 2 tab, 2 equ,
18 ref.
Descriptors: *Model studies, *Nitrogen, Nutrients, Sediments, Anerobic, Aerobic,
Organic matter, Fertilization.
A submodel for the aerobic and anaerobic nitrogen release from sediment is set up.
It was found that the rate of nitrogen release, R is correlated to the nitrogen
content by the following equations: R sub AN=84S sub N + 1.6 (anaerobic); R sub
AE=58S sub N + 1.9 (aerobic); where: S sub N is mg N/ml in the sediment. The
influence of temperature is included by use of an exponential expression, since
the release is governed by a biochemical decomposition of organic matter.
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Section XI
WATER CYCLE
CHEMICAL PROCESSES (GROUP 02K)
75:02K-001
LANDFORM-SOIL-VEGETATION-WATER CHEMISTRY RELATIONSHIPS, WRIGLEY AREA, N.W.T.:
I. MORPHOLOGY, CLASSIFICATION, AND SITE DESCRIPTION,
Walmsley, M.E., and Lavkulich, L.M.
British Columbia University, Vancouver, Department of Soil Science.
Soil Science Society of America Proceedings, Vol 39, No. 1, p 84-88, January-
February 1975. 3 fig, 1 tab, 12 ref.
Descriptors: *Soil-water-plant relationships, *Water chemistry, *Permafrost,
*Canada, Geomorphology, Alpine, Soil types, Soil horizons, Regolith, Bogs, Lichens,
Vegetation, Arctic.
Five landforms occurring in the intermittent permafrost region of the Mackenzie
Valley were described. The five landforms, consisting of distinct soil and
vegetative characteristics occur on a transect from the 1170 m ASL (above sea
level) position at the summit of Cap Mountain, Wrigley area, Northwest Territories,
to approximately 500 m ASL at the base of the slope. Two soils meet the require-
ment of a histic epipedon. An area of stone stripe and stone ring formation was
encountered at approximately 1000 m ASL and an extensive area of lichen-covered
polygonal bogs occurred at approximately 500 m ASL. The soils were described
in relation to environmental factors and the processes of cryoturbation causing
intermittent horizons were discussed.
75:02K-002
DETERMINATION OF TOTAL NITROGEN IN NATURAL WATERS,
Nelson, D.W., Sommers, L.E.
Purdue University, Lafayette, Indiana Department of Agronomy.
Journal of Environment Quality, Vol. 4, No. 4, p 465-468, 1975, 6 tab, 9 ref.
Descriptors: *Analytical techniques, *Methodology, *Water analysis, *Nitrogen,
Vapor compression distillation, Nitrogen compounds, *Pollutant identification.
Total nitrogen determinations in natural waters are complicated because numerous
forms of nitrogen are present. Nitrates are frequently present in substantial
amounts and require pretreatment to be quantitatively reduced to ammonia, which
is measured by the Kjeldahl nitrogen method. Nitrate recovery from plant mater-
ials, fertilizers, and soils succeed when samples are pretreated with reduced
iron in acid media. Hydrogen generated by the iron-with-acid reaction apparently
acts as a reducing agent. In the proposed method water samples are evaporated
and pretreated with reduced iron and sulfuric acid, followed by Kjeldahl digestion
to recover organic nitrogen. Ammonia in the digestion mixture is estimated by
steam distillation and titration. Nitrate and organic nitrogen recovery is
affected by the brand and amount of reduced iron used and boiling the sample
gently with reduced iron and sulfuric acid before digestion. The method measures
up to 2 rag total nitrogen and 0.5 mg nitrate nitrogen in filtered or unfiltered
river and pond waters. It is simple, precise, more rapid than other methods, and
can measure all forms of nitrogen commonly found in natural and waste waters.
Organic nitrogen can be calculated by subtracting inorganic nitrogen from the
total nitrogen found.
75:02K-003
REGIONAL HYDROCHEMISTRY OF NORTH AMERICAN CARBONATE TERRAINS,
Harmon, R.S., White, W.B., Drake, J.J., Hess, J.W.
McMaster University, Hamilton (Ontario). Department of Geology.
Water Resources Research, Vol. 11, No. 6, p 963-967, December 1975. 2 fig, 4 tab,
27 ref.
Descriptors: *Carbonates, *Water chemistry, Groundwater, *Geochemistry, *North
America, Geographical regions, Carbonate rocks, Dolomite, Limestones, Carbon
85
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ioxide, Climates, Temperature, Chemistry, Bicarbonates, Hydrogen ion concentra-
tion, Calcite, Water quality, Spring waters, Ions, Hydrogeology, Variability,
Water temperature, Seasonal, Saturation.
The chemical variation of water samples drawn from carbonate terrains^between
southern Canada and northern Mexico was shown to be divisible into, first,
variations at the local level due to (1) hydrogeologic conditions (time indepen-
dent) , (2) short-term fluctuations of hydrologic factors (stochastic in time),
and (3) seasonal fluctuations of such factors as temperature, precipitation, and
plant growth (systematic in time) and, second, regional climatic effects. These
regional climatic effects can be satisfactorily represented by mean annual
groundwater temperature variation. The regional variation only emerges clearly
if care is taken to compare water samples from the same hydrologic class, in this
case, springwater. The partial pressure of carbon dioxide with which a spring-
water sample is in equilibrium is well represented by log P sub C02=a+bT, where a
is of the order of -3.5 and b is approximately 0.07 with P sub CO2 in atmospheres
and T in degrees Celsius.
75:02K-004
THE SOLUBILITY OF FERRIC OXYHYDROXIDES IN NATURAL WATERS,
Whittemore, D.O., Langmuir, D.
Kansas State University, Manhattan. Department of Geology.
Ground Water, Vol. 13, No. 4, p 360-365, July-August 1975. 1 fig, 4 tab, 22 ref.
Descriptors: *Solubility, *Iron compounds, *Water properties, *Iron oxides,
*Water chemistry, Physical properties. Chemical properties, Phase diagrams, Satu-
ration, Oxidation-reduction potential, Chemical reactions, Geochemistry, Oxides,
Hydrogen ion concentration, Chemical potential, Water.
Iron in groundwater is often present both in solution and as suspended ferric
oxyhydroxides. In most instances amounts of dissolved iron in natural waters are
limited by the solubility of the ferric oxyhydroxides, whether suspended or pre-
sent as part of aquifer materials. Oxyhydroxide solubilities, which range widely
in natural waters, may be described by pQ = -log (Fe+++) (OH-)(OH-)(OH-), where
(Fe+++)(OH-)(OH-)(OH-) is the product of ion activities in the water. pQ values
calculated from Fe(II), Eh, and pH measurements in several types of high iron
ground and surface waters (Fe(II) = 0.02 to 1460 ppm) indicate that most of the
waters are in equilibrium with ferric oxyhydroxides which range from amorphus
material to crystalline goethite (pQ values at 25C from about 37 to 44, respective-
ly. Stabilities generally increase (higher pQ's) in a given water with time. In
general, the lower the dissolved iron, the more soluble is the oxyhydroxide pre-
cipitated and the slower its increase in stability- This was observed both in
coastal-plain groundwaters (pQ = 36.6 - 42.7), and in laboratory aged solutions.
The faster the oxidation and hydrolysis rate of dissolved Fe(II), the lower the
pQ, as shown by the reaction of mineralized spring waters with varying amounts of
surface waters (pQ = 37.2 - 41.5).
75:02K-005
CHEMICAL WEATHERING OF GLAUCONITE,
Abudelgawad, G., Page, A.L., Lund L.J.
Tripoli University, Tripoli, Libya.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 567-571, May-June,
1975. 3 fig, 2 tab, 26 ref.
Descriptors: *Chemical reactions, *Geologic investigations. Geological surveys.
Glauconite samples were collected from geologic cuts in the Barce Plateau in the
eastern part of Libya. The glauconite was associated with limestone, dolomitic
limestone, marl, marl stone, chert, and kaolinite. Samples of the glauconite from
the area of study after removal of carbonates gave x-ray diffraction spacings of
10.0, 7.2, 5.0, 3.6 and 3.3 Angstroms. Spacings of 10.0, 5.0, and 3.3 Angstroms
represent the 001, 002, and 003 reflection of micaceous components. Spacings of
7.2 and 3.6 Angstroms were due to kaolinite. No 060 reflection was observed for
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random samples. The absence of this spacing, although not entirely specific for
glauconite, is indicative of glauconite^like minerals, Petrographic analysis and
chemical composition confirmed that the micaceous mineral studied was glauconite.
75:02K-006
THE ACTIVITY CONCEPT OF PHOSPHATE~ROCK SOLUBILITY,
Chien, S.H., Black, C.A.
International Fertilizer Development Center, Florence, Alabama 35630.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 856-858, September-
October 1975. 4 fig, 11 ref.
Descriptors: *Phosphate, *Soil chemistry, Soil investigations, Chemical reactions.
Variously treated samples of a finely ground Florida phosphate rock were equili-
brated with dilute HC1 solutions, and the ion^activity product of the carbonate
apatite mineral in the phosphate rock was then determined from analyses made on
the solutions. Constant ion-activity products or solubility-product constants
were found within a certain pH range in each instance. The solubility, as reflec-
ted by the numerical value of the constant, decreased with an increase in the
proportion of the phosphate rock dissolved in the solubility determination or pri-
or thereto. After a certain portion of the phosphate rock had been dissolved,
however, no further decrease in solubility was found with further extraction of
the phosphate rock. These results are similar to those obtained previously with
synthetic hydroxyapatite and were interpreted in the same way, namely, that the
solids are not uniform but exist in a range of activities.
75:02K-007
THE CHEMISTRY OF LEAD AND CADMIUM IN SOIL: SOLID PHASE FORMATION,
Santillan-Medrano, J., Jurinak, J.J.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 851-856, September-
October 1975. 8 fig, 2 tab, 14 equ, 17 ref.
Descriptors: *Lead, *Cadmium, *Soil investigations, Soil chemistry, Chemical
reactions.
Equilibrium batch studies were conducted to obtain solubility data of Pb and Cd
in soils. The data were plotted on equilibrium solubility diagrams using pH as
the master variable. In the construction of the diagram the hydroxide, carbonate,
and phosphate compounds of Pb and Cd were given particular attention. Both Pb and
Cd solubility decreased in the soils as pH increased. The lowest values were
obtained in the calcareous soil. Under a given set of conditions, however, Cd
activity in solution was always notably greater than that of Pb.
75:02K-008
THE MECHANISM OF PHOSPHATE FIXATION BY IRON OXIDES,
Parfitt, R.L., Atkinson, R.J., Smart, R.St.C.
Griffith University, Nathan, Brisbane Australia 4111.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 837-841, September-
October 1975. 6 fig, 1 tab, 12 ref.
Descriptors: *Iron oxides, *Iron, *Phosphates, Soil chemistry, Soil investigations,
Chemical reactions.
Infrared spectroscopic techniques have been used to obtain a structural model for
the surface reaction between iron oxides and phosphate ions. Two surface hydroxyl
ions (or water molecules) are replaced by one phosphate ion. Two of the oxygen
atoms of the phosphate ion are coordinated, each to a different Fe3+ ion, resulting
in a binuclear surface complex of the type Fe-O-P(02)-0-Fe. Evidence is given
for phosphate adsorption producing this coordination structure on the surfaces of
goethite, hematite, lepidocrocite, beta-ferric hydroxide, and amorphous ferric
hydroxide gel.
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75:02K-009
THE IMPACT OF MAN ON THE WORLD NITROGEN CYCLE,
McCarl, B.f Raphael, D., Stafford, E.
Purdue University, Department of Agricultural Economics.
Journal of Environmental Management, Vol. 3, No. 1, p. 7-19, January 1975.
Descriptors: *Nitrogen, *Atmosphere, Model studies, Chemical reactions.
The atmosphere is a complex chemical system in which nitrogen emissions, resul-
ting from man's occupancy of the earth, mixes and interacts with natural nitrogen
emissions. By examining the flow of nitrogen within the world, it is possible to
improve our understanding of how man's emissions affect the natural nitrogen cycle.
Obviously the direct effects of man''s nitrogen emissions are multiplied by the
natural cycle. This paper attempts to get a hold upon the multiplier effect.
Through the use of input^output methodology a system with homogeneous flow may be
analyzed, finding the multiplier effects. Homogeneous flow is attained in the
nitrogen cycle by converting all flows into their accompanying nitrogen content.
The system is then modelled and a solution derived. The impact of one ton of
man's nitrogen input is then seen to produce some 800 tons of flow.
75:02K-010
NITROGEN TRANSFORMATIONS IN SOIL AS AFFECTED BY THE FUNGICIDES BENOMYL, DYRENE,
AND MANEB,
Mazur, A.R., Hughes, T.D.
Clemson University, Clemson, SC 29631
Agronomy Journal, Vol. 67, No. 6, p 755-758, November-December. 2 fig, 2 tab,
10 ref.
Descriptors: *Fungicides, *Nitrogen, *Fertilization, *Fertilizers, *Nitrification.
The frequency and extent of fungicide use on putting green turfgrasses prompted
investigations to determine the effect of three commonly used fungicides on N
transformations in soil. Laboratory and field studies were conducted to study
the effect of the following fungicides on nitrification and N mineralization in
soil. The differences in the effects of these fungicides on nitrification and N
mineralization in laboratory as compared to field applications were considered to
be the result of lower rates of application associated with more rapid rates of
degradation under field conditions as contrasted with the high single rates of
application under laboratory conditions.
75:02K-011
RATE OF DISSOLUTION OF PHOSPHATE FROM MINERALS AND SOILS,
Olsen, R.A.
Montana State University, Bozeman, Montana 59715.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 634-639, July-August
1975. 9 fig, 2 tab, 5 egu, 18 ref.
Descriptors: *Phosphate, Nutrients, Soil investigations, Laboratory tests.
A laboratory technique was devised for conveniently measuring the rate of dissolu-
tion of phosphates in minerals and soils. The conditions imposed upon the samples
were believed to be similar in several important respects to those in the close
proximity of plant roots. An equation was derived which was reasonably descriptive
of the dissolution process even in widely different soils. The technique was used
to measure the rate of dissolution of a number of well-characterized rock phosphate
samples and of many soils. The data were found to rate the samples very well with
regard to their value as a source of phosphate to plants.
75:02K-012
NITROGEN FIXATION BY ALGAE IN FESCUEGRASS SOIL CRUSTS,
Reddy, G.B., Giddens, J.
Georgia University, Agricultural Experiment Stations, Athens, 30602.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 654-656, July-August
88
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1975. 1 fig, 3 tab, 21 ref.
Descriptors: *Grasses, *Subsoil, *Nitrogen fixation, Nitrogen, Nutrients, Algae,
Fertilization, Carbon.
Soil crusts and subsoil samples of different ages of tall fescuegrass were collec-
ted and analyzed for N,C, and acetylene reduction. Total N and C in the crust was
0.18% and 2.76%, respectively, in 4-year old soil crust as compared to 0.06% and
9.67% respectively, in fallow soil. The amount of acetylene reduction after 5
days' incubation was 13.77 micro-mole/flask (9.6 cm2) for the 4-year-old sod crust
compared to 3.06 micro-mole/flask for the fallow control. Ammonium nitrate reduced
and liming increased N fixation in the crust. Nitrogen fixation in the crust was
highest at 55% shade. Greater nitrogen fixation occurred when moss was present in
crust.
75:02K-013
THE EFFECT OF AMMONIA AND AMMONIA-SULFUR SOLUTIONS ON NITRIFICATION RATES AND
CHEMICAL PROPERTIES OF A CALCAREOUS SOIL,
Stevens, R.G., Reuss, J.O.
Texas Tech University, Lubbock, Texas 79409.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 787-793, July-August
1975. 7 fig, 2 tab, 4 equ, 25 ref.
Descriptors: *Nitrification, *Soil chemistry, *Soil chemical properties, *Chemical
properties, Ammonia, Soil properties, Nitrate, Nitrite, Sulfur.
Nitrification rates and changes in chemical properties of a calcareous soil were
investigated after injection of liquid anhydrous NH3 and anhydrous NH3-S solutions.
Nitrification rates (on a whole pot basis) of 15.7, 24.3, and 32.2 mg of N per pot
per day were found with the application of 200, 400, and 600 mg of N/pot, respec-
tively- These nitrification rates were recorded during the initial 14 days of the
study when total NO3- accumulation appeared to be linear.
75:02K-014
DISSOLUTION OF ILLITE—A POSSIBLE MECHANISM OF POTASSIUM RELEASE,
Feigenbaum, S., Shainberg, I.
Institute of Soils and Water, Agricultural Research Organization, The Volcani
Center, Bet Dagan, Israel.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 985-990, September-
October 1975. 3 fig, 2 tab, 13 equ, 18 ref.
Descriptors: *Potassium, *Aluminum, *Iron, *Magnesium, Illite, Chemical reactions.
The rate of potassium, aluminum, iron and magnesium release from Fithian illite in
dilute salt solutions and at pH > 3, was studied. It was found that cumulative
cation release was proportional to the square root of the duration of the treatment.
The rate of Al release was similar to the rate of K release, whereas the rate of
Fe and Mg release was about three x that of K and Al release. Since the only
known mechanism for the release of the lattice cations is the dissolution of the
clay, it is proposed that dissolution of the clay lattice is also the dominant
mechanism by which potassium is released from the clay. Two consecutive reactions,
a rapid exchange reaction and a slow first-order reaction, explain the experimental
observations.
75:02K-015
FIXATION OF IRON AND ZINC APPLIED AS CHELATES INTO A SOIL COLUMN DURING LEACHING,
Lahav, N., Hochberg, M.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1213-1215, November-
December 1975. 4 fig, 1 equ, 3 ref.
Descriptors: *Iron, *Zinc, *Leaching, Infiltration, Soil investigations.
89
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The movement of iron in the form of FeEDDHA and FeEDTA and zinc in the form of
ZnEDTA was studied in columns of Rehovot sand under several flow rates and in-the
presence of either Ca(N03)2 or KN03 with the same ionic strength of 9.9375M/liter.
Chloride was used as a tracer. FeEDDHA was neither adsorbed nor fixed by the soil.
Both ZnEDTA and FeEDTA were fixed in the soil column in the presence of Ca2+ but
not in the presence of K+. ZnEDTA was not adsorbed significantly, whereas FeEDTA
was adsorbed in the presence of either KN03 or Ca(N03)2 solutions. Reasonable
agreement was obtained between experimental results and theroretical calculations
of the breakthrough curves, based on the analytical solution of the general disper-
sion equation.
75:02K-016
POTASSIUM IN AN ARID LOESSIAL SOIL: CHARACTERIZATION BY EQUILIBRIUM RELEASE-ABSORP-
TION TO STRONG SALT SOLUTIONS,
James, D.w., Weaver, W.H.
Utah State University, Logan 84322.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1106-1111, November-
December 1975. 6 fig, 1 tab, 24 ref.
Descriptors: *Potassium, Soil chemistry, Soil investigations. Sodium, Magnesium,
Calcium, Absorption.
Shano silt loam soil developed from loessial and Volcanic materials of recent
origin under mild weathering conditions. It contains less than 5% of clay, and
60% or more of silt. The rate of release of mineral K (Km) in this soil to IN Cl
solutions decreased in the order Na greater than Ca greater than Mg much greater
than NH4. Release of Km may have involved some framework silicates, but for prac-
tical purposes the layer silicates controlled Km activity.
75:02K-017
EFFECT OF ADDED SALTS ON NITROGEN RELEASED AND NITRATE LEVELS IN FOREST SOILS
OF THE WASHINGTON COASTAL AREA,
Heilman, P.
Western Washington Research and Extension Center, Puyallup, WA. 98371.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 778-782, July-
August 1975. 2 fig, 4 tab, 20 ref.
Descriptors: *Nitrogen, *Nutrients, Salts, Salinity, Nitrate, Nitrification.
The release and mineralization of N was studied in incubated samples of 10
forested soils from the Washington Coast which had been treated with a variety
of salts. Salts were added in solution at 0.005, 0.05, and 0.2M concentrations
and the samples were incubated at 27C for 7, 14, and 21 days. Release of NH4-N
plus NO3-N increased with increase in the duration of incubation and concentration.
The lowest concentration of salt increased N release over that from distilled
water.
75:02K-018
EFFECT OF TEMPERATURE ON DENITRIFICATION RATE IN SOILS,
Stanford, G., Dzienia, S., Vander Pol, R.A.
Academi of Agriculture, Institute of Soil and Plant Cultivation, Szczecin, Poland.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 867-870, September-
October 1975. 3 fig, 1 tab, 12 ref.
Descriptors: *Denitrification, *Temperature, Soils, Soil investigations, Organic
matter. Soil chemistry, Nitrogen, Nutrients.
The effect of temperature on denitrification rate was studied with nine soils
differing widely in organic matter content and chemical and physical characteris-
tics. In the ragne of 15 to 35C, the temperature coefficient of denitrifification,
Q10, was approximately 2. Denitrification rates at 35 and 45C were similar.
Between 10 and 5C, denitrification rate declined abruptly. The lower limit of the
temperature range conforming to a Q10 of 2 was estimated to be 11C. In this study
90
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of water-logged soils sealed from the atmosphere, denitrification appeared to
obey first-order kinetics.
75:02K-019
POTASSIUM-CALCIUM EXCHANGE EQUILIBRIA IN VOLCANIC-ASH SOILS,
Schalscha, E.B., Pratt, P.F., de Andrade, L.
University of Chile
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1069-1072,
November-December 1975. 3 fig, 5 tab, 12 ref.
Descriptors: *Potassium, *Calcium, Soils, Soil investigations, Soil chemistry,
Chemical reactions.
Potassium-Ca exchange equilibria were determined at potassium adsorption ratios
(PAR) of 0.2, 2.0, and 20 for pH values of 4.8, 6.0, and 7.5 for four volcanic-ash
soils of southern Chile, increases in pH produced large increases in CEC which
were largely balanced by increases in the amount of Ca adsorbed. The increases
in exchangeable K with increase in CEC were relatively small. The relative affin-
ities for K versus Ca at a PAR of 0.2 indicated that for each soil a small, but
nearly constant, amount of negative charge had a high specificity for K. Beyond
this small amount of CEC with a high affinity for k, the affinities for K were
relatively low.
75:02K-020
ENVIRONMENTAL IMPLICATIONS OF N FIXATION BY SOYBEANS,
Johnson, J.W., Welch, L.F., Kurtz, L.T.
Illinois University, Urbana, IL Department of Agronomy.
Journal of Environmental Quality, Vol. 4, No. 3, 1975. p 303-306, 3 fig, 2 tab,
7 ref.
Descriptors: *Nitrogen, *Nitrogen fixation, *Soybeans, Crop production, Corn,
Crop response, Fertilizers, Fertilization, Nutrients.
The objective was to measure inorganic N removal from soil by soybenas grown at
different N levels. Nodulating and non-nodulating isolines of 'Clark' soybeans
were planted on Flanagan silt loam in 1972 and 1973. Fertilizer rates of 0, 112,
224, and 448 kg N/ha as Ca(N03)2 enriched with 1% 15N were applied. Symbiotically
fixed N decreased from 48 to 10% of the total N in the above-ground plant as
applied fertilizer N increased from 0 to 448 kg/ha. Net removals of N by soybean
grain were 61, 109, 135, and 149 kg/ha at 0, 112, 224, and 336 kg/ha, respectively.
The study indicates that soybeans are good scavengers for inorganic N in soils.
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Section XII
WATER CYCLE
ESTUARIES (GROUP 02L)
75:02L-001
EXPANSION OF SALT-WATER ZONE DUE TO WE'LL DISCHARGE,
Kashef, A-A. I., Smith, J.C.
North Carolina State University, Raleigh. Department of Civil Engineering.
Water Resources Bulletin, Vol. 11, No. 6, p 1107-1120, December 1975. 7 fig, 2
tab, 10 ref.
Descriptors: *Saline water-freshwater interfaces, *Water wells, *Saline water
intrusion, Coasts, Aquifers, Pumping, Aquifer characteristics, Computer models,
Water managementtApplied), Groundwater movement, Hydraulic conductivity, Specific
weight, Potentiometric level, Equations, Natural flow, Theis equation, Storage
coefficient, Groundwater, Saline water, Wells.
In coastal confined aquifers, the extent of saltwater wedge due to natural ground-
water flow can be determined by available methods. If water is pumped by a dis-
charge well, the quality of the water depends upon the rate and duration of
pumping as well as the location of the well. A study was made to find the extent
of the progress of salt-water intrusion due to the operation of one discharge
well, taking into account various conditions of aquifer properties, pump capaci-
ties, natural flow, time effects, and well locations. Dimensionless solutions
for specific conditions were obtained by means of a simple computer program.
Range of most common conditions was discussed. One of the main findings of the
study was that salt water may be pumped out of a well even if it is located in an
initially totally fresh-water zone beyond the natural salt/fresh-water interface.
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Section XIII
WATER SUPPLY AUGMENTATION AND CONSERVATION
WATER YIELD IMPROVEMENT (GROUP 03B)
75:038-001
PREDICTING REDUCTION IN WATER LOSSES FROM OPEN CHANNELS BY PHREATOPHYTE
CONTROL,
Bouwer, H.
Agricultural Research Service, Phoenix, Arizona. Water Conservation Laboratory.
Water Resources Research, Vol. 11, No, 1, p 96-101, February 1975. 7 fig, 2
tab, 16 ref.
Descriptors: Phreatophytes, *Water loss, *0pen channels, Channels, Seepage,
Water tables, *Flood plains, Streams, Evapotranspiration, Groundwater, Vegetation,
Evaporation•
A procedure was presented for calculating seepage from a stream due to uptake
of groundwater by vegetation or evaporation from soil in the floodplain. The
calculation required that the relation between evapotranspiration rate and
water table depth be known. When these relations were available for a given
floodplain before and after removal of phreatophytes, the reduction in seepage
losses from the stream due to phreatophyte removal could be computed. To sim-
plify the calculation process, the curves relating evapotranspiration rate and
water table depth, which are generally sigmoid (curved in two directions),
could be approximated by step functions of the same area. Potential water
savings by phreatophyte control were calculated for step functions that were rep-
resentative of deep-rooted vegetation, shallow rooted vegetation, and bare soil.
In addition to the depth from which groundwater could be evaporated before and
after phreatophyte removal, the water savings were affected by the vertical
distance between the water level in the stream and the floodplain.
75:03B-002
INFILTRATION AND RUNOFF FOR SMALL FIELD PLOTS UNDER CONSTANT INTENSITY RAINFALL,
Swartzendruber, D., and Hillel, D.
Hebrew University, Rehovoth (Israel). Department of Soil and Water Science.
Water Resources Research, Vol. 11, No. 3, p 445-451, June 1975. 6 fig, 1 tab,
8 ref, 1 append.
Descriptors: *Infiltration, *Runoff, *Field crops, *Rainfall, Infiltrometers,
Soil surfaces, Rainfall intensity, Simulated rainfall.
A relatively simple infiltration equation Was used to express the family of in-
filtration flux time curves that occurred under constant rate water application
(sprinkling or rain) from the time that excess water appeared at the soil sur-
face. The equation was easily integrated for cumulative water excess as a func-
tion of time, which in turn allowed taking into account a simplified static
surface volume to calculate cumulative water runoff. The runoff equation so
obtained was tested by means of a sprinkling infiltrometer used on plots of 1 sq
m and was found to express with good accuracy the measured cumulative plot run-
off as a function of time. The field data, taken with a modified Purdue-Wisconsin
sprinkling infiltrometer on Rehovot loamy sand, were then utilized successfully
for obtaining the ultimate steady infiltration flux, even when the period of
measuring transient runoff was less than 1 hour and the total runoff less than
1 cm of water. The value of steady flux so obtained was in good agreement with
that found under the condition of continuous ponding of water on the soil surface.
75:03B-003
WIND EFFECTS ON CHEMICAL FILMS FOR EVAPORATION SUPPRESSION AT LAKE HEFNER,
Crow, F.R., and Mitchell, A.L. Jr.
Oklahoma State University, Stillwater. Dept. of Agricultural Engineering.
Water Resources Research, Vol. 11, No. 3, p 493-495, June 1975. 4 fig, 8 ref.
93
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Descriptors: *Evaporation control, *Winds, *Films, *Lakes, *Oklahoma, Evapora-
tion, Hexadecanol, Octadecanol, Slurries, Application equipment, Application
methods, Retardants, Thin films, Research and development, Alcohols, Rates of
application, Wind velocity.
An evaporation suppression research project was conducted at Lake Hefner, Okla-
homa, where water-based slurries of hexadecanol and octadecanol were applied
at the upwind side of the lake by an offshore sprinkler system. The distribu-
tion system was designed for maximum film cover under south winds. The chemical
was applied at a variable rate adjusted to the demand created by local wind
speed and direction. The application rate required to replace film removed by
the wind, in terms of pounds per hour per foot of distribution line perpendicular
to the wind, averaged 6.5-8 times greater than for an experimental pond with a
similar application system. The upper wind speed limit for successful film
application was 13 miles per hour (mph). Distribution studies were made to
determine the percent of time that wind speeds and directions were favorable to
the application of film, i.e., with speeds less than 13 mph and direction between
135 degrees and 225 degrees azimuth. Under wind conditions experienced in
Oklahoma it was difficult to maintain continuous film cover because of the fre-
quency of occurrence of high wind speeds and shifts in wind direction.
75:038-004
ANALYSIS OF FLOW THROUGH VEGETATION,
Petryk, S., Bosmagian, G. Ill
Florida University, Gainesville, Florida, Department of Civil and Costal Engineer-
ing.
Journal of the Hydraulics Division Vol. 101 No. HY7 p 871-884, July 1975. 9 fig,
15 ref, 2 append.
Descriptors: *Flow, *Flow characteristics, Open channel flow, Open channels,
Hydraulics, Vegetation, Vegetation effects.
A flow resistance model for unsubmerged vegetation conditions is presented. It
is quantitatively described by Eq. 12, which predicts the n value in terms of
vegetation density, the hydraulic radius, and the Manning bottom roughness value
without the vegetation for the special case of a uniform density of vegetation
with height, applicable to some heavily treed flood plains. The Mannings n
value increases in proportion to the 2/3 power of the hydraulic radius. This
assumes that the flow occurs through heavily vegetated areas where the total
shear force on the channel boundary is negligible compared to' total drag force
on the vegetation.
75:03B-005
WORKSHOP FOR AN ASSESSMENT OF THE PRESENT AND POTENTIAL ROLE OF WEATHER MODIFICA-
TION IN AGRICULTURAL PRODUCTION,
Grant, L.O., Reid, J.D.
Department of Atmospheric Science, Colorado State University, Fort Collins,
Colorado 80523.
Compilation of Workshop Materials of Workshop held at Colorado State University,
July 15-18, 1975. 236 p, 22 fig, 13 tab, 53 ref.
Descriptors: *Weather, *Weather modification, *Agriculture, *Weather patterns,
Rainfall, Crop production.
The broad objective of the assessment of the present and future role of weather
modification in agricultural production is to make an authoritative evaluation of
the present and potential role that weather modification can take in increasing
national and world agricultural production. A specific objective includes the
preparation of an authoritative document that can receive wide distribution and
provide for extensive utilization of the results of the assessment. This document
will: 1) Identify the geographical areas and types of weather modification re-
search that can have the greatest impact on agricultural production and other
renewable resources; 2) Provide background and guidance to NSF and other federal
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and state research managers on areas and types of weather modification research
that can have the greatest impact on agricultural production and other renewable
resources. This can apply to those with responsibilities in the discipline areas
of weather modification, meteorology, agriculture and atmospheric science; 3) Pro-
vide information to state and federal public administrators (Office of Technical
Assessment, OMB, etc.), legislators, courts and the general public that can assist
them in making wise decisions and plans regarding applications of weather modifi-
cation; 4) delineate the needs, required efforts, and methods for a longer term,
continuing evaluation of the interrelations between weather modification and agri-
culture.
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Section XIV
WATER SUPPLY AUGMENTATION AND CONSERVATION
USE OF WATER OF IMPAIRED QUALITY (GROUP 03C)
75:030001
TRICKLE IRRIGATION WITH WATER OF DIFFERENT SALINITY LEVELS,
Seifert, W.J. Jr., Hiler, E.A., Howell, T.A.
William F. Guyton& Associates, Austin, Texas.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 1,
p 89-94, January-February 1975. 8 fig, 2 tab, 16 ref.
Descriptors: *Salinity, *Saline water, *Irrigation, *Irrigation effects,
*Sorghum, Surface irrigation, Lysimeter, Leaching, Crop response.
' Objectives of this study were (a') to determine effects of different concentra-
tions of saline water on grain sorghum production and soil environment using
trickle irrigation, and (b) to evaluate effects of irrigation water at one
electrolyte concentration with both surface and trickle irrigation. The study
was conducted in a sheltered lysimeter installation during two successive seasons.
A Norwood silt loam soil was utilized in the lysimeters. Salts were purposely
not leached between seasons so that salinity buildup effects could be evaluated.
Numerous crop, soil and meteorological parameters were measured and evaluated to
quantify effects of various treatments on the crop and soil.
75:03C-002
EFFECTS OF FREQUENCY OF SPRINKLING WITH SALINE WATERS COMPARED WITH DAILY DRIP
IRRIGATION,
Bernstein, L., Francois, L.E.
Agricultural Research Service, Riverside California Salinity Lab.
Agronomy Journal, Vol. 67, No. 2, p 185-190, March-April, 1975. 2 fig, 6 tab,
13 ref.
Descriptors: *Sprinkier irrigation, *Crop production, *Plant physiology,
*Irrigation water, Sprinkling, Saline water, Salts, Socium chloride. Calcium
chloride, Salt tolerance, Foliar, Leaves, Irrigation effects, Plant growth,
Application methods.
Bell peppers (Capsicum frutescens) were sprinkled every 2.3,3.5, and 4.75 days
with low salt (450 mg/liters) and medium and high salt waters (1,000 and 2,000
mg/liter of added NaCl + CaC12). Additional plots were drip irrigated with the
same waters. Sprinkling with the low-salt water and drip irrigation with all
3 waters caused no leaf damage. Plants sprinkled every 2.3 days with the 2 high
salt waters suffered more leaf burn and produced lower yields than plants sprink-
led less often. Sprinkling with the high-salt water reduced yields more than
50% at all sprinkling frequencies. Injury and yield loss appear to be related
primarily to foliar salt absorption.
75:03C-003
SALINITY-OZONE INTERACTIVE EFFECTS ON ALFALFA YIELD AND WATER RELATIONS,
Hoffman, G.J., Maas, E.V., Rawlins, S.L.
Agricultural Research Service, Riverside, California Salinity Lab.
Journal of Environmental Quality, Vol. 4, No. 3, p 326-331, July-September, 1975.
4 fig, 5 tab, 16 ref.
Descriptors: *Salinity, *Ozone, *Soil-water-plant relationships, *Alfalfa,
Irrigation water, Saline water, *Crop production, Plant growth, Agriculture,
Air pollution, Leaves.
The effect of ozone of forage yield of alfalfa (Medicago sativa L. cv. Moapa)
was determined at four controlled salinity levels (NaCl and CaC12) having osmotic
potentials of -40, -200, -400, and -600 kilopascals. For nonsaline treatments,
ozone greatly reduced yields when alfalfa was exposed to daily 2-hour periods of
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10-20 parts per hundred million; concentrations that are prevalent in many agri-
cultural areas. As salinity increased, ozone had less effect on yield, and a
-25% greater yield was produced with salinity at moderate, but not detrimental
levels. Salinity at all levels or ozone at 20 parts per hundred million increased
water use efficiency of alfalfa, and low concentrations of ozone had no effect
on water-use efficiency. Both ozone and salinity together were required to in-
crease leaf diffusion resistance.
75:030004
RESPONSE TO THREE SEMIDWARF MEXICAN WHEATS TO DIFFERENT AERATION CONDITIONS
IN THE ROOTING MEDIUM AT A CONSTANT SALINITY LEVEL,
Everarda, N. Stolzy, L.H., Mehuys, G.R.
Ascuela Nacional de Agriculture Chapingo (Mexico).
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 515-518, May-June,
1975. 2 fig, 2 tab, 13 ref.
Descriptors: *Soil gasses, *Aeration, *Oxygen requirements, *Root zone, *Plant
growth, *Wheat, Agriculture, Soil environment, Environmental control, Soil physi-
cal properties, Soil properties, Soil chemistry, *Soil-water-plant relationships,
Soil physics, Dissolved oxygen, Oxygenation, Zone of aeration, Crop response,
Plant physiology, Salinity, Root development, Mexico, Transpiration.
The response of 3 newly developed Mexican wheat (Triticum aestivum L.) varieties,
Nuri 70, Inia 66, and Siete Cerros 66, to low oxygen at constant salinity of
-4 bars in the rooting medium was tested in a water culture experiment under
growth chamber conditions. Oxygen concentrations in solution were maintained at
1.5, 5.2, and 7.6 ppm. All varieties were affected by low oxygen at high salinity
but Inia 66 had the greatest adaptability. Oxygen concentrations of 1.5 ppm de-
creased plant dry-matter production by 50% and reduced transpiration by 54-65%.
Root porosities increased with each decrease in oxygen content, with Inia 66
showing the largest increase. A 5.2 ppm oxygen concentration in solution was
found to be optimum for grain yield, water use, and leaf and root dry matter pro-
duction if Inia wheat was grown without salinity stress in the root zone.
75:03C-005
MODEL OF SOIL SALINITY EFFECTS ON CROP GROWTH,
Childs, S.W., Hanks, R.J.
Utah State University, Logan. Department of Soil Science and Biometeorology.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 617-622, July-
August 1975. 9 fig, 2 tab, 12 ref.
Descriptors: *Saline soils, *Crop response, *Mathematical models, Soil physical
properties. Crop production, Osmotic pressure, Irrigation design, Irrigation
efficiency. Irrigation systems, Salt balance, Water management(Applied), Drainage,
Evapotranspiration, Root distribution, Water quality, Soil water movement, Soil
moisture, On-site tests, Climatic data, Groundwater, Irrigation.
The model considered properties of the soil, water, plant, and atmospheric system
to predict relative crop yield. Crop yield predictions assume a direct relation
between dry matter production and transpiration. The only salinity effects con-
sidered were osmotic potential. The influence of initial soil salinity on crop
growth depended upon the crop type and irrigation management. Predictions made
of salt buildup over several years showed that some water management systems
would produce high yields for several years before salt buildup would decrease
yields? Predictions showed that the influence of irrigation system uniformity on
salinity buildup and yield reduction is very important.
75:03C-006
USE OF GEOTHERMAL WATER FOR AGRICULTURE,
Bishop, A.A.
Utah State University.
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Aerojet Nuclear Company, Idaho National Engineering Laboratory, Idaho Falls,
Idaho. 83401. No. 1221, June 1975. 10 fig, 1 tab, 30 ref. 26 pages.
Descriptors: *Geothermal studies. Agriculture, Irrigation, Water quality,
Crop production.
The use of geothermal resources in agriculture will depend largely upon the site
specific conditions of the resources. Both water and heat have many applications
in agricultural production and the technologies for their use are generally
known. When the quantity, quality, and the location of the geothermal water sup-
ply is known, the value of the water for irrigation can be readily estimated. The
value for other uses such as for food and feed processing, space heating and cool-
ing for crops and for animals is less readily determined. Application of geo-
thermal water for irrigation purposes as well as other farm uses is extensively
discusses. Advantages and disadvantages of the use of geothermal water for animal
production are presented. An extensive set of references are included to aid the
reader in gaining additional insight into the water quantity and quality require-
ments for agricultural applications.
75:03C-007
SOIL WATER EXTRACTION BY ALFALFA,
Brun, L.J., Worcester, B.K.
North Dakota State University, Fargo, Dept. of Soils.
Agronomy Journal, Vol. 67, No. 4, p 586-589, July-August 1975. 3 fig, 2 tab, 9
ref.
Descriptors: *Saline soils, *Salinity, *Alfalfa, Crop response. Crop production,
Soil water, Moisture tension, North Dakota, Montana.
Saline seeps have developed because of the accumulation of water beyond the root-
ing zone of annual crops. The purpose of this experiment was to show the poten-
tial of alfalfa to extract soil water under a variety of textural and salinity
conditions. Core samples were taken in alfalfa fields and fields under crop-fallow
management to evaluate their present water content, 15 atm. percentage, texture,
and salinity level. Significant extraction of soil water occurs to depths of 3
to 4 m. Alfalfa extracted soil water held at a tension greater than 15 atm. in
both saline and non-saline segments of the soil profile. A minimum soil moisture
level was reached at the 1.22 to 2.44 m depth in alfalfa fields maintained 5 years.
Alfalfa is an invaluable crop for reducing soil wetness to alleviate the saline-
seep problems of western North Dakota and eastern Montana.
75:03C-008
INFLUENCE OF SALINITY AND N-P FERTILITY LEVELS ON MINERAL CONTENT AND GROWTH OF
SORGHUM IN SAND CULTURE,
Patel, P.M., Wallace, A., Wallihan, E.F.
California University, Riverside, CA.
Agronomy Journal, Vol. 67, No. 5, p 622-625, September-October 1975. 1 fig, 3 tab,
19 ref.
Descriptors: *Grain sorghum, *Soil salinity, *Salinity, *Crop response, Irriga-
tion, Irrigation effects, Crop production, Agriculture, Salt tolerance. Fertilizers
Fertilization, Nitrogen.
Plant growth is characteristically depressed at certain levels of salt concentra-
tions yet it sometimes responds to fertilizers even though growth depression can
be expected to reduce nutrient requirements and even though fertilizer application
increases salinity to some degree. This study was designed to examine tension
zones involving interactions between nutrient supply (N and P) and salt concentra-
tions. Grain sorghum was chosen for this study because it is commonly grown in
regions of irrigated agriculture where soil salinity is often a problem. Plants
were grown to maturity in automatically operated sand culture equipment at two
levels each of N and P, each subjected to added Ca-Na chloride salinity levels
of zero, medium (EC=10 MMho/cm) and high (EC=20 mmho/cm). Vegetative growth was
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depressed to about 50% of control at both medium and high salinity, while grain
production was depressed to about 35% at medium salinity and to almost none at
high salinity.
75:030-009
SALINITY EFFECTS ON RICE AFTER THE BOOT STAGE,
Kaddah, M.T., Lehman, W.F., Meek, B.D., Robinson, F.E.
Imperial Valley Conserv. Res. Center, Brawley, CA.
Agronomy Journal, Vol. 67, No. 3, p 436-439, May-June 1975. 1 fig, 1 tab, 17 ref.
Descriptors: *Rice, *Salinity, *Crop response, *Salt tolerance, Flood irrigation,
Crop production.
Effect of salinity on rice after the boot stage has been controversial in the
literature. Some authors maintain that rice is sensitive to salt at flowering,
whereas others have found no evidence to support these views. The present
greenhouse study evaluates the interaction after the boot stage of salinity, soil
texture, and rate of drainage on rice development.
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Section XV
WATER SUPPLY AUGMENTATION AND CONSERVATION
CONSERVATION IN AGRICULTURE (GROUP 03F)
75:03F-001
IRRIGATION RUNOFF RECOVERY IN THE DESIGN OF CONSTANT FURROW DISCHARGE IRRIGATION
SYSTEMS,
Stringham, G.E., Hamad, S.N.
Utah State University, Logan. Department of Agricultural and Irrigation
Engineering.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 1,
p 79-84, January-February 1975. 3 fig, 2 tab, 4 ref.
Descriptors: *Irrigation, *Irrigation design, *Irrigation engineering, *Furrow
irrigation, Irrigation systems, Agricultural engineering, Furrow systems,
Runoff.
A method was presented to design an Irrigation Runoff Recovery System which will
permit a constant furrow discharge throughout the irrigation set by irrigating
the first set entirely from supply water, the last set entirely from pumped
runoff water, and by varying the set size between the two. Since the system
requires a variable number of furrows from set to set, a table and charts were
presented to give the number of furrows required in successive sets, number of
sets required, number of furrows in the late set irrigated entirely from stored
runoff, storage volume required, potential water savings, area covered by the
storage pond, and recirculating-pump flow rate.
75:03F-002
ECONOMICS OF INCREASED MOBILITY FROM TILE DRAINAGE,
Aldabagh, A.S.Y., Beer, C.E.
Mosul University, Mosul, Itaq., College of Engineering.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 1,
p 116-121, January-February 1975. 4 fig, 3 tab, 16 ref.
Descriptors: *Drainage, *Drainage engineering, *Drains, *Drainage systems,
Economics, Economic impact.
The purpose of this study was to estimate the added economic benefit of tile
drainage from increased mobility of agricultural machinery. This was achieved by
first relating the performance of vehicles to soil strength in terms of rating
cone index. The rating cone index was evaluated by the cone penetrometer and re-
molding equipment. Relations then were developed between soil strength, moisture
content, and depth to water table for poorly drained soils. Existing data were
used in predicting the behavior of water table for various drain spacings and soil
conductivities. A tile depth of 4 ft, a tile diameter of 0.5 ft, and a depth to
the impervious layer below the drain of 4 ft, were assumed. The results were
applied to determine the increased number of days in which machine operations can
be performed during the planting season when tile drains with various spacings
are used.
75:03F-003
LIMITED IRRIGATION OF GRAIN SORGHUM IN ALTERNATING STRIPS WITH WHEAT,
Musick, J.T., Dusek, D.A.
United States Department of Agriculture, Southwestern Great Plains Research Center,
Bushland, Texas.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 3,
p 544-548, May-June 1975. 5 fig, 3 tab, 12 ref.
Descriptors: *Sorghum, *Wheat, Irrigation, Irrigation practices. Furrow irriga-
tion, Surface irrigation. Irrigation effects, Crop response.
Grain sorghum and winter wheat are the two major irrigated crops in the Southern
High Plains. In 1973, irrigated grain sorghum was grown on 863 200 ha and irriga-
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ted winter wheat on 486 000 ha (New 1973) . Declining groundwater tables and well
yields necessitate conservation and efficient use of limited irrigation water
supplies. Management practices are needed for reducing water application in
furrow irrigated systems. This paper reports results from the grain sorghum
phase of a 6-year field study in which grain sorghum and winter wheat were grown
in alternating 4.56-m wide drill strips.
75:03F-004
IRRIGATING CORN AND GRAIN SORGHUM WITH A DEFICIENT WATER SUPPLY,
Stewart, J.I., Misra, R.D., Pruitt, W.O., Hagan, R.M.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 2,
p 270-280, March-April 1975. 7 fig, 8 tab, 15 ref.
Descriptors: *Corn, *Sorghum, Irrigation, *Irrigation effects, *Irrigation
practices, Crop response, Evapotranspiration, Crop production.
Maximizing crop production with limited irrigation water requires quantitative
information about differential yield responses to given levels of water deficit
in each major growth period. The pollination period of corn is widely thought of
as a "Critical period" in this regard. Our findings support the idea that corn
grain yield is especially vulnerable to water deficits during the pollination
period, provided the crop has experienced little or no ET deficit in the late veg-
etative period, ending at first tassel. However, we find the susceptibility of
corn yield to deficits in the pollination period to be greatly lessened if there
have been prior deficits. This is expressed as a "conditioning" factor which is
important to the planning of irrigation programs which, either by choice or. by
exigencies of water supply, include ET deficits during one or more major growth
periods. Grain sorghum yield is found to be markedly less sensitive to ET deficits
than corn, and there is no indication that a conditioning factor operates with
this crop. The yield reduction ratios found for the two crops are summarized.
75:03F-005
IRRIGATION SYSTEM MANAGEMENT FOR REDUCING PEAK ELECTRICAL DEMANDS,
Stetson, L.E., Watts, D.G., Corey, F.C., Nelson, I.D.
United States Department of Agriculture, Agricultural Research Service, Lincoln, NE.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 2,
p 303-306, 311, March-April 1975. 3 fig, 1 tab, 9 ref.
Descriptors: *Electric Power, *lrrigation operation and management, Irrigation
effects, Nebraska, Irrigation, Agriculture, Energy.
Peak summer power demand and the ratio of summer to winter loads limit electric
energy for irrigation in Nebraska. An experiment conducted to schedule operation
of irrigation systems during hours of lower electrical demand showed that peak
summer demand loads can be reduced. The peak electrical demand of, a power dis-
trict was reduced, but crop yields were not. The scheduled irrigation systems
used less total energy and water. Power districts and irrigators are expected to
use results of this experiment either to increase the area irrigated or to reduce
future energy and water demands.
75:03F-006
ANHYDROUS AMMONIA APPLICATION IN IRRIGATION WATER VERSUS MECHANICAL AND ITS
EFFECT ON CORN YIELDS,
Mulliner, H.R., Frank, K.D.
Nebraska University, Lincoln, Department of Agricultural Engineering
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 3,
p 526-528, May-June 1975. 5 tab, 2 ref.
Descriptors: *Corn, *Crop response, Irrigation water, Irrigation, Fertilizers,
Fertilization.
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Furrow irrigators can make their systems perform double duty by putting fertili-
zer in the water. Anhydrous ammonia(NH3), can be applied along with the water,
saving energy and the time consumed in conventional application. Anhydrous
ammonia is not leachable in the ammonia form. Thus, high soil moisture conditions
immediately after application present no problem. With soil temperatures above
50 F, ammonia is converted to the nitrate form. Nitrogen as nitrate is more avail-
able for plant use and becomes leachable if excess water penetrates through the
soil profile. Injecting and applying NH3 through irrigation systems requires
good water management. Presently it is not recommended for sprinkler systems due
to the high volatilization loss of ammonia. The purpose of this experiment was
to compare corn yields where the NH3 was applied in the surface irrigation water
(Gated pipe) to that of mechanical application (soil injected).
75:03F-007
NITROGEN CONSERVATION UNDER CORN PLANTED IN QUACKGRASS SOD,
Bennett, O.L., Stanford, G., Mathias, E.L., Lundberg, P.E.
United States Department of Agriculture, Agricultural Research Service,
Morgantown, WV
Journal of Environmental Quality, Vol. 4, No. 1, p 107-110, January-March 1975.
3 fig, 4 tab, 18 ref.
Descriptors: *Fertilization, *Fertilizers, *Grasses, *Nitrogen, Crop response,
Corn.
The mechanics of growing corn in a grass sod using the no-tillage concept have
recently been developed. However, little is known about the fate of fertilizers,
especially nitrogen, or the potential uses of such plant species as quackgrass in
this management system. Silage yields of corn were determined from field studies
in which corn sod-planted in quackqrass, treated with six rates of atrazine, was
compared to conventionally planted corn. The effects of no tillage and conven-
tional tillage, using two rates of atrazine on total soil N, and N mineralization
potential were compared. Yields of corn silage produced in herbicide-treated
quackgrass were signigicantly higher than yields from conventional tillage. In
the first year, silage yields increased with rates of atrazine. Quackgrass per-
sisted for a 2-year period at the three lowest rates of atrazine but not at higher
rates. After the first season, mineral N (largely NO(3)-N) was significantly
greater under untilled quackgrass than under plowed plots. However, by the follow-
ing spring differnces associated with tillage method had disappeared. Soil
N mineralization potential, NO, and total N in the 0- to 15-cm layer were consider-
ably higher for untilled than for plowed soils. However, in untilled plots, these
values were unaffected by rate of atrazine.
75:03F-008
DEEP TILLAGE OF GRADED-FURROW-IRRIGATED PULLMAN CLAY LOAM,
Musick, J.T., Dusek, D.A.
United States Department of Agriculture, Southwestern Great Plains Research
Center, Bushland, TX.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 2,
p 263-269, March-April 1975. 9 fig, 3 tab, 14 ref.
Descriptors: *Soil environment, *Soil investigations, *Soil management, *Soil
properties. Soil texture, Crop response, Surface irrigation, Irrigation, Furrow
irrigation.
Pullman clay loam was deep tilled with a large moldboard plow to 40, 60, and
80 cm in 1966 at the USDA Southwestern Great Plains Research Center, Bushland,
Texas. Deep tillage was compared with 20-cm normal tillage depth. The deep
tillage treatments partially or completely penetrated slowly permeable clay Bt
horizons that extended to about the 60-cm depth and partially mixed the clay Bt
with the more permeable clay loam surface A horizon. The long-term effects were
evaluated during the production of nine crops over a 7-yr period. The major
effects on increasing water intake and yields under limited irrigation were obtained
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from increasing tillage depth from 20 to 40 cm. Increasing tillage depth to 60
and 80 cm, which completely penetrated the slowly permeable clay Bt horizon, had
a smaller additional effect on water intake and little or no additional effect
on yields.
75:03F-009
OPTIMIZING WATER UTILIZATION THROUGH MULTIPLE CROPS SCHEDULING,
Huang, W., Lianf, T., Wu, I.
Hawaii University, Honolulu, Agricultural Engineering Department.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 2,
p 293-298, March-April 1975. 8 fig, 2 tab, 19 ref.
Descriptors: *Model studies, *Water utilization, *Hawaii.
This study is divided into two parts. The first part deals with the construction
of a mathematical model that will determine the cropping pattern for the efficient
use of water. The second part applies the model to the Lalamilo area. Two case
studies are presented. The difference between the two case studies is that the
first allows less choice of planting time than the second one. The modeling work
was carried out in the following steps: 1) Construction of a tentative operation
schedule chart that will realistically relate the water demands to their supplies
in short time periods. 2) The chart is then used as a basis for formulating
constraints. Information obtained from the tentative operation schedule chart was
used to formulate constraints and to identify the number of decision variables.
A computer program was developed to translate the information obtained from the
operation chart into proper MPS (mathematical programming system/360) input form.
75:03F-010
WHEAT YIELD MODELS WITH LIMITED SOIL WATER,
Neghassi, H.M., Heermann, D.F., Smika, D.E.
Colorado State University, Fort Collins, Colorado.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 3,
p 549-553, 557, May-June 1975. 4 fig, 3 tab, 24 ref.
Descriptors: *Wheat, *Model studies, Soil water. Soil moisture, Crop response,
Yield equations, Crop production.
Wheat dry matter yield was highly correlated to cumulative ET and cumulative
daily relative ET. The linear models with approximate marginal productivities of
200 kg/ha/cm and 100 kg/ha/cmcm may be sufficient for predicting dry matter yields
when soil water is limiting. The scaling of ET by corresponding daily ETO is
believed to reconcile climatic differences. Further tests and comparisons are
necessary to establish ranges for the coefficients and applicability of the
scaling.
75:03F-011
2020 HINDSIGHT: ANOTHER FIFTY YEARS OF IRRIGATION,
Dreyfus, D.A.
Committee on Interior and Insular Affairs (U.S. Subcommittee on Water and Power
Resources.
Journal of the Irrigation and Drainage Division, ASCE, Vol. 101, No. IR2, Proceed-
ings paper No. 11363, p 87-04, June 1975. 4 ref.
Descriptors: *Irrigation, *Planning, *Water resources, *Water supply. Regional
development, Reclamation, Agriculture, Management, Decision making, Water policy,
Colorado River.
Water resources management has been a concern of governments from the time of the
earliest recorded civilizations. In the United States, policies that have evolved
over several decades to guide the Federal role in water resources planning and
development are no longer relevant to national problems and goals. Water resources
planning presently is in disarray because mechanical analysis has been substituted
for continued policy guidance. The nation appears to be approaching a major
reevaluation of governmental water resources policy. New objectives and a new
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Federal role will be defined. Recent social and economic conditions indicate that
there will be renewed national interest in the management of western water re-
sources and that irrigated agriculture will continue to be a significant function
in Federal water policy.
75:03F-012
NO-TILL SEEDING OF IRRIGATED SORGHUM DOUBLE CROPPED AFTER WHEAT,
Allen, R.R., Musick, J.T., Wood, F.O., Dusek, D.A.
United States Department of Agriculture, Bushland, TX. Southwestern Great Plains
Research Center.
Transactions of the American Society of Agriculture Engineers, Vol. 18, No. 6,
p 1109-1113, November-December 1975. 7 fig, 3 tab, 8 ref.
Descriptors: *Sorghum, *Till, Seed treatment, Irrigation, Wheat, Crop response,
Agriculture, Crop production.
Irrigated grain sorghum was successfully no-till seeded into wheat residue
immediately following wheat harvest in the Southern High Plains. Grain sorghum
grown with clean tillage and seeding was grown for comparison. No-till seedlings
generally emerged faster, grew taller, and matured up to 5 days earlier than
controls. Grain yields for a 5-yr study averaged 5,690 kg/ha for no-till and
5,070 kg/ha for clean-till, a 12 percent increase. No-till required only one-
fifth as much time between crops to prepare and plant a seedbed. No-till reduced
fuel requirements, including harvest, by 55 percent.
75:03F-013
EROSION CONTROL WITH NO-TILL CROPPING PRACTICES,
McGregor, K.C., Greer, J.D., Gurley, G.E.
United States Department of Agriculture Sedimentation Laboratory, Oxford, MS.
Transactions of the American Society of Agricultural Engineers, Vol. 18 No. 5,
p 918-920, September-October 1975. 3 fig, 1 tab, 9 ref.
Descriptors: *Erosion, *Erosion control, *Till, Crop Production.
No-till cropping systems (continuous soybeans, soybean-corn rotation, and soybeans
double-cropped with wheat) were very effective in reducing erosion. Soil loss
from conventional-till soybeans was significantly higher than that from any of
the no-till systems. No significant differences in soil loss were greatest
during storms with excessive rate rainfall.
75:03F-014
CROP RESPONSE TO CHISELING AND IRRIGATION IN SOILS WITH A COMPACK A2 HORIZON,
Doty, C.W., Campbell, R.B., Reicosky, D.C.
Coastal Plains Soil and Water Conservation Research Center, Southern Region.
Transactions of the American Society of Agricultural Engineers, Vol. 18 No. 4, p
668-672, July-August 1975. 7 fig, 4 tab, 14 ref.
Descriptors: *Crop response, *Chiseling, *Irrigation, *Irrigation effects, Crop
production. Corn, Furrow irrigation.
The objective of this study was to determine the yield of millet and sweet corn
under four soil-water management regimes and to evaluate yield differences in
terms of oxygen stress, depth of rooting, and soil water status in a coarse-
textured soil with a compact A2 Horizon. The experiment was conducted on a Varina
sandy loam soil with a slope of less than 1 percent. Millet was grown as a test
crop in 1969 and 1970 and primary tillage treatments as main plots, with and with-
out furrow irrigation.
75:03F-015
OPTIMIZATION OF WATER USE EFFICIENCY UNDER HIGH FREQUENCY IRRIGATION II. SYSTEM
SIMULATION AND DYNAMIC PROGRAMMING,
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Howell, T.A., Hiler, E.A., Reddell, D.L.
New Mexico State University, Las Cruces, Agricultural Engineering Department.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 5,
p 879-887, September-October 1975. 3 fig, 5 tab, 18 ref.
Descriptors: *Model studies, *Simulation analysis, *Irrigation efficiency,
*Irrigation practices, Irrigation design, Irrigation, Soil moisture.
An environmental simulation model (temperature, rainfall, and potential evapora-
tion) was developed for Temple, Texas. The model was similar to that developed
by Jones et al. (1972) for State College, Mississippi. Using Monte Carlo tech-
niques, these daily environmental data could be simulated for input to the soil
water balance model. The simulation results adequately represented the stochastic
serial-correlation of these variables. The soil water balance model was modified
to allow for root zone extension, runoff calculations, and grain sorghum leaf
area index simulation (Ritchie and Arkin 1973). The model can separately calculate
the plant and soil evaporation components. The root zone was assumed to linearly
expand from 150 mm at germination to 1750 mm at the rate of 32 mm/day. Runoff
was computed by the SCS equation.
75:03F-016
POWER FACTORS AND ELECTRICAL DEMANDS OF CENTER-PIVOT IRRIGATION MACHINES,
Stetson, L.E., Nelson, S.O.
United States Department of Agriculture, Agricultural Research Service, North
Central Region.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 4,
p 673-676, July-August, 1975. 4 fig, 2 tab, 3 ref.
Descriptors: *Irrigation effects, *Electric power demand, *Electric power costs,
Irrigation practices, Irrigation, Irrigation system.
Some operating characteristics of electrically driven, center-pivot irrigation
machines were measured in the field. Peak power demands over fractional-minute
periods were about twice the average demand. Power factors for the machines ranged
between 0.3 and 0.5, and at least 1 kVA per connected hp was necessary to meet
average electrical demands. Higher average power was required for faster rates
of travel, but peak power demand was independent of travel rate. Power required
for movement of machines around drops in drive-motor circuits did not exceed the
tolerance limits for the 460-V motors and controllers.
75:03F-017
POTENTIALLY BENEFICIAL USES OF SULFURIC ACID IN SOUTHWESTERN AGRICULTURE,
Miyamoto, S., Ryan, J., Stroehlein, J.L.
Arizona University, Tucson, Arizona Agricultural Experiment Station.
Journal of Environmental Quality, Vol. 4, No. 4, p 431-437, October-December 1975.
63 ref.
Descriptors: *Acids, Waste disposal, Land reclamation, Sodium.
Production of sulfuric acid is projected to exceed market demand in the south-
western USA if current air pollution control regulations are fully implemented by
means of acid plants. Considerable quantities of surplus acid can be used bene-
ficially for reclaiming sodium-affected calcareous soils, increasing the availa-
bility of phosphorus and certain micronutrients, treating alkaline and ammoniated
irrigation water, controlling certain weeds and soil-borne pathogens, improving
range grass establishment and growth, and for several other purposes. Principles
involved in these uses are reasonably well established, but studies are required
to determine effective use especially in the area of field application.
75:03F-018
LEACHING LOSSES OF AMMONIUM AND NITRATE IN THE RECLAMATION OF SAND SPOILS IN
CORNWALL,
Dancer, W.S.
Liverpool University, Liverpool, England. Botany Department.
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Journal of Environmental Quality, Vol. 4, No. 4, p 499-504, October-December 1975.
4 fig, 3 tab, 15 ref.
Descriptors: *Leaching, *Ammonium compounds, *Ammonium salts, Fertilizers,
Fertilization, Nitrate, Land reclamation, Nitrogen.
Reclamation studies on sand spoils in Cornwall have shown a difficulty in main-
taining adequate levels of nitrogen for plant growth. Information is presented
to show that the movement of N03(-) and NH( + ) is highly correlated with rainfall
(r=0.89 and 0.92, respectively). Nitrate leaching is more serious than NH4
leaching and calculations show that more than 98% of the N03(-) fertilizer applied
to bare sand spoil will be leached beyond the surface 20 cm with an average month
of summer rainfall (9.7 cm). Maximum inorganic-N fertilizer recoveries of 40
kg/ha are predicted for grass swards established on spoils flattened by earth-
moving equipment, while recoveries < 20 kg N/ha are likely on steeply sloping
sand heaps.
75:03F-019
STEADY INFILTRATION FROM BURIED, SURFACE, AND PERCHED POINT AND LINE SOURCES IN
HETEROGENEOUS SOILS: II. FLOW DETAILS AND DISCUSSION,
Philip, J.R., Forrester, R.I.
Division of Environmental Mechanics, P.O. Box 821, Canberra Cety, A.C.T.,
2601, Australia.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 408^414, May-June
1975. 10 fig, 19 equ, 7 ref.
Descriptors: *Soil water, *Soil water movement, *Subsurface irrigation, Furrow
irrigation, Irrigation systems, Soil physical properties.
Part I (Philip, 1972) developed physically relevant source solutions of the quasi-
linearized steady infiltration equation, generalized to apply to heterogeneous
soils with conductivity depending exponentially on both moisture potential and
depth. This paper discussed the results in further detail, and includes graphs
of a wide range of solutions.
75:03F-020
ENERGY INPUTS TO IRRIGATION,
Batty, J.C., Hamad, S.N., Keller, J.
Utah State University, Logan. Department of Mechanical Engineering; and Utah State
University, Logan. Department of Manufacturing Engineering.
Journal of the Irrigation and Drainage Division, Proceedings of the American
Society of Civil Engineers, Vol. 101, No. IR4, Proceedings paper 11810, p 293-307,
December 1975. 13 fig, 5 tab, 3 equ, 15 ref.
Descriptors: *Energy, *Irrigation, *Irrigation systems, Land use, Operations,
Water utilization, Efficiencies, Agriculture, United States, Installation, Pumping,
Irrigation water costs, Water demand.
Energy inputs to irrigation are dramatically increasing as irrigated agriculture
expands to meet world food demands and more sophisticated technologies are devel-
oped to increase water use efficiency. In this study, nine irrigation systems,
designed for a specific land area, are analyzed, and the total energy inputs com-
puted for each system. The analysis includes energy inputs to manufactured compo-
nents and installation as well as operation and maintenance. The expected life
of each system and the energy value of salvable materials are also taken into ac-
count. It is concluded that a practical balance must be established between maxi-
mizing water use efficiency and minimizing water use efficiency and minimizing
energy inputs to the irrigation system. The installation energy requirements are
by no means negligible compared to the energy requirements for pumping. Where
water is in short supply or is only available at a high energy cost, the energy
conservation associated with high water use efficiency in any type of system may
outweigh all other energy inputs.
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75:03F-021
SEDIMENT FROM DRAINAGE SYSTEMS FOR A HEAVY SOIL,
Schwab, G.O., Nolte, B.H., Brehm, R.D.
Ohio State University, Columbus, Ohio, Department of Agricultural Engineering.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 7 p, 3 fig, 2 tab, 10 ref.
Descriptors: *Sediment discharge, *Sediinent load, *Sediment transport, *Sediment
yield, *Drainage, Drainage practices, Drainage systems, Drains.
Sediment losses from tile and surface drainage systems in a lakebed soil in north-
ern Ohio were measured for 6 years (1969-74). Average annual losses were 2369
Kgs/Ha from tile only and 3710 Kgs/Ha for surface only. Expected losses for the
combination tile and surface drainage system were 3260 Kgs/Ha. Losses ranged from
about 200 to 9000 annually- Average net losses from sprinkler irrigation were
negligible and usually more sediment was added than removed in the drainage water.
Sediment concentration in tile flow from irrigation increased significantly with
the antecedent soil moisture content. Concentrations were high at the beginning
of flow but decreased to a nearly constant level after 20 hours. A possible
explanation for the high concentrations is that the sediment moved in suspension
with the water and not through the soil cracks. The total estimated soil loss
from the surface drained only plots was within one percent of the measured losses.
The estimated losses were computed from the universal soil loss equation. For
the no-till plots the estimated losses were 16 percent higher than the measured
whereas conventional tillage losses were 11 percent lower. A linear regression
was significant at the 99% level. Estimates using a runoff factor rather than the
rainfall factor in the soil loss equation were 41 percent of the measured values
compared to 89 percent using the rainfall factor.
75:03F-022
IRRIGATION SCHEDULING AND SUGARBEET PRODUCTION,
Jardine, G.D., Fox, S.D.
Agricultural Research, Northern Ohio Sugar Company, Fremont, Ohio 43420-
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 6 p, 4 tab, 6 ref-
Descriptors: *Sugarbeets, Irrigation, Irrigation practices, Crop response,
Colorado, Soil moisture, Irrigation efficiency, Schedyling.
This paper centers on irrigation scheduling and pugarbeet production- The empha-
sis is upon the results of Great Western Sugar Company's irrigation studies and
the recommendations for a successful sugarbeet irrigation program. Recommendations
are: 1) begin the season with a full °£ nearly full soil moisture profile; 2)
give the crop a boost with light irrigations for emergence and after thinning, if
necessary; 3) schedule irrigations throughout the season using climate, crop,
and soil data. Include also, the irrigators experience and habits where possible
in determining the actual schedule; and 4) utilize irrigation scheduling to deter-
mine the cut-off dates for late season irrigations. These recommendations all
point toward managing the soil moisture so the maximum sugar production can be
attained by utilizing all the resources available to the grower. Today's sugar-
beet grower must be a good manager. All tools researchers can provide to better
manage irrigations will help insure the continued production of high yielding,
high quality sugarbeets.
75:03F-023
TRICKLE AND SPRINKLER IRRIGATION OF GRAIN SORGHUM,
Ravelo, C.J., Hiler, E.A., Howell, T.A.
Texas A&M University, College Station, Texas 77843.
Presented at the 1975 Winter Meeting of the American Society of the Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 17 p, 5 fig, 3 tab, 15 ref.
Descriptors: *Crop response, *Sorghum, *Irrigation practices, *Irrigation effects,
*Sprinkier irrigation, Irrigation systems.
107
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Hie crop response and water use efficiency (ratio of weight of grain harvested to
centimeters of total crop water use) of grain sorghum was investigated using
trickle and sprinkler irrigation. Also the effects of different trickle irriga-
tion frequencies on the crop growth and ultimate grain yield were studied. Two
different experimental investigations are reported in this paper, one conducted
in 1972 and another in 1974. The 1972 sprinkler vs. trickle experiment had the
following two irrigation treatments with three replications each: 1) trickle
irrigated three times per week, and 2) overhead sprinkler irrigated three times
per week. The irrigation amounts in each treatment were 1.1 times soil water
losses as measured by the neutron method with gravimetric sampling in the upper
10 cm. The 1974 trickle irrigation frequency experiment had the following three
treatments with three replications each: 1) trickle irrigated thrice weekly, 2)
trickle irrigated twice weekly, and 3) trickle irrigated once weekly. From the
results of these experimental investigations and for the given conditions of this
study, the following conclusions can be drawn: 1) There were no significant
differences in yield or water use efficiency when using trickle and sprinkler irr-
igation with a thrice-weekly frequency; and 2) Different trickle irrigation fre-
quencies (once, twice, and thrice weekly) with the same overall application
amounts had no significant effect on grain sorghum yield or water use efficiency.
75:03F-024
SPRINKLER EVAPORATION LOSSES IN THE SOUTHERN PLAINS,
Clark, R.N., Finley, W.W.
United States Department of Agriculture, Agricultural Research Service, Southwest-
ern Great Plains Research Center, Bushland, Texas.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 11 p, 5 fig, 6 ref.
Descriptors: *Sprinkler irrigation, *Evaporation, *Irrigation, *Irrigation
effects, Water conservation. Wind velocity.
Water discharged from irrigation sprinklers was caught in specially designed con-
tainers in order to determine evaporation losses during sprinkling. Two nozzle
sizes and three water pressures were tested during the study period. When the
average wind velocity was less than 4.5 m/s (10 mph), the evaporation losses were
generally less than 10% and the vapor pressure deficit had the greatest influence
on the amount of evaporation. When average wind velocities were between 4.5 m/s
and 8.5 m/s, losses increased exponentially with wind velocity. The wind velocity
was the predominate factor under these conditions and evaporation losses ranged
from 10 to 30%. Since much of the Southern Plains has an annual average wind
velocity greater than 6 m/s, average evaporation losses can be expected to exceed
15%.
75:03F-025
SPRINKLER IRRIGATION PERCOLATION LOSSES,
Dylla, A.S., Shull, H.
United States Department of Agriculture, Agricultural Research Service, Morris,
Minnesota 56267,
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 8 p, 1 tab, 3 equ, 6 ref.
Descriptors: *Sprinkler irrigation, *Percolation, *Percolating water, Irrigation/
Soil water, Soil water movement, Irrigation effects, Uniformity coefficient.
A workable procedure is presented for estimating sprinkler irrigation percolation
losses. The method is based on the amount of water applied, the soil moisture
deficit, and the sprinkler distribution uniformity coefficient.
75:03F-026
MEETING FUTURE WATER REQUIREMENTS BY WATER CONSERVATION,
Hedlund, J.D.
Soil Conservation Service, Golden, Colorado.
108
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Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 9 p, 2 fig, 3 tab.
Descriptors: *Water conservation, Irrigation, Irrigation practices, Water demand,
Water utilization, Irrigation efficiency, Irrigation water, Water quality, Return
flow, Water supply.
Applying best management practices available to irrigation could (1) reduce 1975
withdrawals of 195 million acre-feet by 48 million acre-feet, (2) salvage 8 million
acre-feet of incidental losses, (3) reduce pollutant-laden return flow by 47
million acre-feet and (4) meet year 2000 production demands.
75:03F-027
FACTORS INFLUENCING THE LOSS OF NITROGEN AND PHOSPHORUS FROM A TRACT OF IRRIGATED
LAND,
Busch, J.R., Fitzsimmons, D.W., Lewis, G.C., Naylor, D.V., Yoo, K.H.
Agricultural Engineering, University of Idaho, Moscow, Idaho.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 11 p, 2 fig, 4 tab, 11 ref.
Descriptors: *Nitrogen, *Phosphorus, *Irrigation effects, Surface irrigation,
Irrigation, Irrigation practices, Leaching, Nutrients, Return flow. Water
pollution.
A study was conducted to identify factors that influence the loss of nitrogen and
phosphorus from a tract of irrigated land. A multiple regression analysis was
used to determine the influences of nine identifiable factors. The statistics of
the analytical relationships obtained indicate that they are suitable for estima-
ting the amounts of nutrients lost in surface runoff from the studied tract. The
amounts of chemical constituents lost in surface runoff from a gravity irrigated
farm are dependent upon several independent variables including total solids lost,
amounts of nutrients applied, and water retained on the field. Specific conclu-
sions drawn from the study area are: 1) The amounts of nutrients in the surface
runoff were significantly affected by the amounts of total solids and water lost
in surface runoff, and the amounts of nutrients applied in headwaters. 2) More
soluble and total phosphorus and ammonia nitrogen were lost to surface runoff in
earlier irrigations than in later irrigations. 3) Increasing the percentage of
applied water retained on a field and reducing the amounts of fertilizer added to
irrigation water would decrease the amounts of all nitrogen forms lost in surface
runoff. All results presented are applicable to the study site monitored. How-
ever, the relationships developed and conclusions drawn may be applied with cau-
tion to similar areas managed with similar cultural practices.
75:03F-028
ESTABLISHING WATER, NUTRIENT AND TOTAL SOLIDS MASS BUDGETS FOR A GRAVITY-IRRIGATED
FARM,
Fitzsimmons, D.W., Busch, J.R., Lewis, G.C., Naylor, D.V., Carlson, R.D.
Agricultural Engineering, University of Idaho, Moscow, Idaho.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 15 p, 3 fig, 5 tab, 4 equ,
5 ref.
Descriptors: *Irrigation, *Irrigation practices, Furrow irrigation, *Surface
irrigation, Evapotranspiration, Nutrients, Leaching, Return flow, Water pollution.
Mass budgets were established for a surface-irrigated farm and used to determine
net losses of water, nutrients and solids from the farm. Data for establishing
the budgets were obtained by monitoring surface flows and groundwater during two
irrigation seasons. Flow and chemical analysis data were combined, using a
computer model, to obtain the budgets.
75:03F-029
IRRIGATION REUSE SYSTEMS—A PROPOSED NEW ASAE ENGINEERING PRACTICE,
109
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Hart, W.E.
Department of Agricultural Engineering, Colorado State University, Fort Collins,
Colorado 80523.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 24 p, 4 fig, 1 tab, 30 ref.
Descriptors: Irrigation Systems, "Irrigation practices, Irrigation design,
Irrigation engineering, Irrigation water, Irrigation, Agriculture, Furrow
irrigation, Surface irrigation.
A subcommittee of the Surface Irrigation Technical Committee (SW-242) has prepared
a draft document which will be submitted for consideration as an ASAE Engineering
Practice. This document, which is reproduced here, has six sections—purpose and
scope, definitions, system analysis, determination of runoff, system design, and
costs. Reader comments are solicited.
75:03F-030
TILLAGE, MATRIC POTENTIAL, OXYGEN AND MILLET YIELD RELATIONSHIPS IN A LAYERED
SOIL,
Campbell, R.B., Phene, C.J.
Coastal Plains Soil and Water Conservation Research Center, Florence, South
Carolina.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 17 p, 6 fig, 17 ref.
Descriptors: *0xygen, *Crop response, *Soil tests, *Soil investigations, *Soil
environment, Soil horizons, Soil moisture.
A unique relationship was established between soil 02 content and soil water ma-
tric potential from which the 02 content may be estimated from soil matric poten-
tial data. Yield of millet was a function of soil 02 content from 2 to approxi-
mately 15%. At soil 02 levels greater than 15%, the growth of millet was
independent of soil 02 content. Harvesting millet twice during the growing season
which included a 14-day wet period produced significantly greater yields than
harvesting three times. Chiseling the soil 35 cm deep one year before the experi-
ment resulted in yields greater than those of the plowed soil, when the soil was
in a wet condition, simulating a stormy 14-day period. Under a moderate soil
water regime, in which the soil matric potential did not exceed -400 mb, aeration
was adequate and the yield of millet was unaffected by tillage depth. Under high
matric potential conditions, -45 to -87 mb, chiseling was beneficial as a means
of partially alleviating soil oxygen stresses associated with a wet soil condition.
75:03F-031
AN EXPERIMENTAL BURIED MULTISET IRRIGATION SYSTEM,
Worstell, R.V.
United States Department of Agriculture, Agricultural Research Service, Snake
River Conservation Research Center, Kimberly, Idaho.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 15 p, 8 fig, 2 tab, 7 ref.
Descriptors: "Irrigation, "Irrigation systems, Irrigation design, Irrigation
effects, Irrigation efficiency. Irrigation practices, Water conservation, Soil
moisture, Soil moisture movement.
Criteria for the design, construction, and operation of an experimental buried
lateral, gravity multiset irrigation system are presented. The system has a
potential water application efficiency of 80% with very little runoff or erosion
without automatic controls. With automatic controls and with water available on
demand, light, frequent irrigations can be applied with efficiencies of 90 to
95%. The energy required to operate the system is minimal and labor requirements
involve only periodic inspection and maintenance services. Cost and benefit
estimates indicate that this system may be economically feasible, practical, and
attractive at a time of rising energy costs and labor shortages.
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75:03F-032
IMPROVEMENT OF WATER APPLICATION OF SELF-PROPELLED SPRINKLER IRRIGATION SYSTEMS,
Barefoot, A.D.
Oklahoma State University, Stillwater. Department of Agricultural Engineering.
Available from the National Technical Information Service, Springfield, VA 22161
as PB-245 762, $3.25 in paper copy, $2.25 in microfiche. Completion Report (1975)
17 p, 3 fig, 7 tab, 10 ref.
Descriptors: *Irrigation systems, *Sprinkler irrigation, *Uniformity coefficient,
Trafficability, *Evapotranspiration, Evaporation, Winds, Root zone, *0klahoma.
The number of center-pivot sprinkler irrigation systems is increasing in the
central Great Plains. The reasons for this increase are their labor-saving advan-
tages and versatility. The system's ability to irrigate rolling terrain with a
wide range of application depths accounts for its versatility. The objectives of
this project were to evaluate the depth and uniformity of application of a center-
pivot system and to determine the depth of water stored in the crop root zone,
evaporation losses and trafficability problems of a typical system during field
conditions. Data were collected from a 1300 foot, electrically driven system.
Both size and spacing of the nozzle heads are varied to obtain desired application
rates on this system. The soil type was sand and the crop was peanuts. The
average coefficient of uniformity was 85.2 with a standard deviation of 2.48. The
uniformity appeared to decrease linearly with wind speed for the range tested.
The average evaporation loss was 15.5 percent with 20.4 percent occurring during
daytime irrigations and 10.6 percent at night. No trafficability problems were
encountered on the sandy soil. Five systems were tested in the Oklahoma Panhandle.
The systems varied in both design and lengths. Three of the systems were electri-
cally powered and two were water driven. The average coefficient of uniformity
for the five systems was 81.7. Only minor traction problems were observed in the
clay loam or loam soils.
75:03F-033
TWO-DIMENSIONAL SOLUTES TRANSFER DURING NONSTEADY INFILTRATION: LABORATORY TEST
OF MATHEMATICAL MODEL,
Bresler, E., Russo, D.
Cornell University, Ithaca , New York.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 585-587, May-
June 1975. 3 fig, 3 ref.
Descriptors: *Solutes, *Infiltration, Irrigation, Irrigation effects, Irrigation
practices, Soil-water movement, Mathematical model.
The theory of two-dimensional transport of solutes during nonsteady infiltration
from trickle sources, as developed previously, was compared with experimental
results. A laboratory experiment was conducted under conditions similar to those
assumed in the two-dimensional plane flow model. The agreement between theory and
experiment as expressed by salt concentration distribution and location of wetting
fronts, is generally good. This suggests that the theory is applicable to many
situations similar to the conditions studied.
75:03F-034
VARIATIONS IN THE NATURAL ABUNDANCE OF N OF WHEAT PLANTS IN RELATION TO FERTILI-
ZER NITROGEN APPLICATIONS,
Shearer,G., Legg, J.O.
Center for the Biology of Natural Systems, Washington University, St. Louis, MO.
63130.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 896-901, September-
October 1975. 4 fig, 3 tab, 11 ref.
Descriptors: *Nitrogen, *Fertilization, *Fertilizers, *Wheat, Crop response.
Measurements were made by two laboratories of the per mill (15)N excess of winter
wheat plants grown at five locations in Pennsylvania on experimental plots. The
plots were fertilized with N at various rates. The results from both laboratories
111
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showed a consistent decline in per mill (15)N excess with increasing rates of N
application. Such a decrease in per mill (15)N excess is consistent with increas,
ing contributions of fertilizer N to the plants as the rate of application in-
creased, given that fertilizer N has a lower 15N content than the soil N. me
coefficients of regression of per mill (15)N excess of wheat on N application r"=
were always negative and usually significantly different from zero. The regression
coefficients computed from the results of the two laboratories were not signiri-
cantly different from each other in 12 of 16 experiments. There was, however, a
systematic, unexplained difference in the results from the two laboratories. A
regression of one set of data on the other resulted in a regression coefficient
significantly different from one, the theoretically expected value.
75:03F-035
FINAL REPORT ON FERTILIZER MOVEMENT THROUGH SOIL RESULTING FROM RAINFALL,
Phung, H.T., Bartholic, J.F., Buchanan, D.W.
Institute of Food and Agricultural Sciences, Florida University.
Contract No. 3-35371, July 1975. 39 p, 15 fig, 4 tab, 3 equ, 24 ref.
Descriptors: *Nutrients, *Rainfall, Fertilizer, Leaching, Irrigation effects,
Agriculture.
This study had a number of components in addition to the determination of nutrient
loss from the orchard. Those additional components are discussed first in this
report since they provide background information needed to better interpret the
results on nutrient loss. These parts include, first, a characterization of the
soil in the orchard. Second, since soil moisture measurement was an important
component, a brief discussion of the method used for determining soil moisture is
included. The third part is a very major section involving evaluation of the wa-
ter balance components occurring in the grove during the time nutrient loss was
being determined. Because of their importance, figures for evapotranspiration are
given by short periods for all of 1973. The fourth component covers nutrient loss
from the peach orchard. This study involved the determination of over a thousand
determinations of elements in the water outflow during the year-long study. Thus,
it was possible to characterize in detail not only the major elements being leached
from the orchard, but also minor elements. In addition, following the application
of fertilizer, nutrients in the soil were monitored with respect to time after
fertilizer application. Thus, considerable additional sampling was involved in
characterizing the nutrients at three different depths versus time after applica-
tion.
75:03F-036
SCIENTIFIC IRRIGATION SCHEDULING FOR SALINITY CONTROL OF IRRIGATION RETURN FLOWS,
Jensen, M.E.
U.S. Department of Agriculture, Agricultural Research Service, Western Region,
Snake River Conservation Research Center, Kimberly, Idaho 83341.
Environmental Protection Technology Series, November 1975. 91 p, 5 fig, 4 tab,
21 equ, 97 ref, 1 append.
Descriptors: *Irrigation, *Irrigation efficiency. Return flow, Irrigated land,
Leaching, Salinity, Management, *Scheduling.
A comprehensive review is presented of irrigation water management principles,
factors to be considered in improving irrigation water management, leaching require-
ments, climatological approaches to irrigation scheduling, scope of irrigation
scheduling in 1974, basic concepts of scheduling services, and probable effects of
scientific irrigation scheduling on salinity of return flows. A definition of
irrigation water management efficiency is presented to evaluate the annual volume
of irrigation water used relative to the optimum amount needed for maximum annual
crop production or income. The term considers the minimum, but essential water
needed for both consumptive and nonconsumptive uses. The lack of significant
changes in irrigation efficiency during the past several decades is discussed and
attributed to problems associated with the management of a complex soil-crop-envi-
ronment system, a lack of economic incentives to make improvements, and ineffective
112
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traditional approaches to improve irrigation scheduling. New proposed minimal
leaching practices are discussed. The author concludes that substantial improve-
ments in irrigation efficiencies can be made before the proposed minimal LF are
reached on most western irrigated projects.
75:03F-037
USE OF AMENDMENTS TO REDUCE WATER REQUIREMENTS FOR STAND ESTABLISHMENT OF SMALL-
SEEDED CROPS,
Dennis, R.E., Edmond, C.W., Robbins, C.W.
Arizona University, Tucson, Arizona.
Project Completion Report, 15 pages, August 1975. 16 ref.
Descriptors: Seeds, Water conservation, Sugarbeets, Alfalfa, Acids, Soil amend-
ments.
Soil crusting after planting is a serious problem in stand establishment of
small-seeded crops in the Southwest. When crusting occurs in a saline, warm, soil,
stand establishment problems are especially severe. It is customary to use costly
irrigation water to keep seedbed surfaces moist after planting to reduce soil
crusting and to lower soil temperatures. Phosphoric acid (24% and 12%) and sulfuric
acid (95%) were evaluated to determine their effectiveness in reducing soil
crusting and reducing the amount of water required to obtain stands of sugarbeets,
alfalfa, wheat and barley. Phosphoric acid, applied in 4-6 cm bands over the seed
row at planting and before irrigation, reduced crusting and increased sugarbeet
and alfalfa seedling emergence. Emerged seedlings from phosphoric acid treated
plots were larger and one irrigation (10-15 ha cm/ha) was saved in stand establish-
ment. Sulfuric acid applied in bands reduced soil crusting. Soluble salts in the
seed zone resulting from band application of sulfuric acid killed or damaged
seedlings. Sulfuric acid, when applied in irrigation water to saline-sodic soils,
improved plant growth and water use efficiency.
75:03F-038
TRICKLE IRRIGATION DESIGN,
Karmeli, D., Keller, J.
Rain Bird Sprinkler Manufacturing Corporation, Glendora, California. 1975.
133 pages.
Descriptors: *Irrigation, *Irrigation systems, Irrigation practices, Irrigation
efficiency, Crop response, Soil water movement, Hydraulics, Design.
This text provides a rather complete review of trickle irrigation with sufficient
handbook material and instruction for system design. It has been written with
the student engineer, research and adviser, as well as existing and potential
users, in mind. To enhance its usefulness, this text is written with both metric
and English units of measurement.
75:03F-039
ANNOTATED BIBLIOGRAPHY ON TRICKLE IRRIGATION,
Smith, S.W., Walker, W.R.
Colorado State University, Fort Collins, Colorado. Agricultural Engineering
Department, Environmental Resources Center.
Information Series No. 16, June 1975. 61 p.
Descriptors: *Irrigation, *Irrigation effects, *Irrigation practices, *Irrigation
design, *Irrigation efficiency, Irrigation engineering, *Irrigation systems,
Evapotranspiration, Fertilization, Crop response.
Trickle irrigation (or drip irrigation) is a relatively new approach to supplying
agricultural crops with moisture where natural precipitation is inadequate.
Research relating to trickle irrigation is being conducted throughout the world,
including a significant effort in the United States. To date, the application
of this irrigation method in Colorado has been considered feasible only in orchards
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or greenhouses. However, increased emphasis on improving irrigation water manage-
ment capabilities for salinity control, revegetation of lands disturbed by mining
activities, etc., necessitates further examination. This report presents a com-
pilation of annotated references from approximately 30 sources of technical -Ll'<:er"
ature. Its purpose is to allow the reader to assess the existing knowledge ana
evaluate information relevant to the problems being encountered as well as indica-
ting where further study is necessary.
75:03F-040
EPA AND AGRICULTURE: ESTABLISHING A PARTNERSHIP,
Train, R.E.
Environmental Protection Agency, Washington, D.C. 20460.
Journal of Soil and Water Conservation, Vol. 30, No. 1, p 33-35. January-February
1975.
Descriptors: *Agriculture, *Environmental control, *Environment, Pollution, Water
quality-
Ecologists often note that nothing man does in a natural system is done in isola-
tion. Pollutants often cross natural barriers or otherwise interact to exercise
profound effects on the world environment. On the other hand, corrective action
taken in one place may produce benefits in others as well. Fortunately, water
pollution control and soil and water conservation require identical measures in
most instances. The control of soil erosion, for example, though it cannot pre-
vent the loss of some soluble compounds, does keep waterways free of sediments
with their attached, insoluble pesticides and nutrients. And pollution control
itself is a vital part of any water conservation project.
75:03F-041
ENVIRONMENTAL CONSIDERATIONS IN EXPANDING AGRICULTURAL PRODUCTION,
Crosson, P.R.
Latin American Program for Resources for the Future, Inc., 1755 Massachusetts
Avenue, N.W., Washington, D.C. 20036.
Journal of Soil and Water Conservation, Vol. 30, No. 1, p 23-28. January-February
1975.
Descriptors: *Environment, *Environmental effects, Agriculture, Crop production,
Grains, Soybeans.
The environmental impacts of increasing agricultural production in the U.S. will
depend upon the magnitude of the increase and the kind of technology employed
to bring it about. In each case the range of possibilities is so wide that well-
grounded statements about likely outcomes are difficult. The great imponderable
with respect to production is the growth of foreign demand. This has been the
major element in the recent dramatic shifts in prices and production of U.S. agri-
cultural commodities, particularly grains and soybeans. U.S. farmers could easily
accommodate prospective increases in domestic demand at reasonable costs, probably
with a diminishing land base and a set of conservation and other measures designed
to control the environmental impacts of expanded production. When the scenario is
broadened to include foreign demand, however, the outlook becomes less clear and
the possibility of greatly increased pressures on the environment emerges.
75:03F-042
SULFURIC ACID FOR THE TREATMENT OF AMMONIATED IRRIGATION WATER: I. REDUCING
AMMONIA VOLATILIZATION,
Miyamoto, S., Ryan, J., Stroehlein, J.L.
Arizona University, Tucson, 85721.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 544-548, May-June
1975. 4 fig, 7 tab, 14 equ, 11 ref.
Descriptors: *Irrigated water, *Ammonia, *Ammonification, Water quality,
Fertilizers, Fertilization, Acids.
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Effects of sulfuric acid applied to ammoniated irrigation waters on ammonia vola-
tile losses are analyzed theoretically and evaluated by laboratory and field ex-
periments. Volatile loss of ammonia from irrigation waters is directly related
to the concentration of NH40H. Sulfuric acid application reduces the concentration
of NH40H relative to the total N applied as anhydrous or aqua ammonia, principally
by lowering pH. This consequently reduces ammonia volatile loss, e.g., by as much
as 50% when acid is applied at rates equivalent to ammonia. The reduction of
ammonia loss by sulfuric acid application through forming HNH4S04- is nil. Simul-
taneous application of acid and ammonia may serve as a practical means of control-
ling ammonia loss as well as disposing of large quantities of projected surplus
acid without reducing pH of irrigation water.
75:03F-043
CONVENTIONAL AND CONTROLLED-RELEASE NITROGEN SOURCES FOR RICE,
Wells, B.R., Shockley, P.A.
Arkansas University, Rice Branch of the Agricultural Experiment Station, Stuttgart,
Arkansas 72160.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 549-551, May-June
1975. 3 tab, 8 ref.
Descriptors: *Soils, *Fertilizer, *Fertilization, *Ureas, *Nitrogen, *Rice,
Crop production, Crop response.
Tests were conducted for the years 1967-1972 with rice to compare various formu-
lations of sulfur-coated urea (SCU) and iso-butylidene diurea, (I.B.D.U.) with
urea and ammonium sulfate as nitrogen sources on both silt loam and clay soils.
The N sources were applied either preplant or topdress at rates up to 235 kg/ha
to drill-seeded rice which was flooded at approximately 2 weeks following seedling
emergence. Grain yields, dry weight, and N uptake indicated that the controlled-
release N sources could be used to regulate rate on N supply to the plant through-
out the growing season. Growth of direct seeded rice was slowed considerably
during the early part of the growing season due to the slow rate of N release but
grain yields were not drastically altered. Grain yields on the silt loam soils
following use of the controlled-release N fertilizers were consistently equal to
those following use of urea or ammonium sulfate. On the clay soils under inter-
mittent flooding, use of SCU resulted in increased yields as compared to urea
applied preplant, and in one year resulted in increased yields as compared to urea
applied in split topdress doses. Both SCU and I.B.D.U. were suitable N sources
for rice growing under the water management systems employed in these studies.
75:03F-044
WIND, SPRINKLER PATTERNS, AND SYSTEM DESIGN,
Seginer, I., Kostrinsky, M.
Faculty of Agricultural Engineering, Technion, Haifa, Israel.
Journal of the Irrigation and Drainage Division, Vol. 101, No. IR4, p 251-264,
December 1975. 8 fig, 3 tab, 3 equ, 6 ref.
Descriptors: *Sprinkler irrigation, *Wind velocity, Irrigation, *Irrigation
design, Irrigation efficiency, *Distribution patterns.
This study includes: 1. Due to the fact that wind speed and solar radiation were
not correlated in the data on which this study was based, it was possible to show
that the wind speed was not directly contributing to the water loss during sprink-
ling. 2. A method of sprinkler patterns reconstruction was developed, which
yielded representative interpolated patterns, as well as reliable extrapolated
patterns for no-wind conditions. 3. It was theorized and demonstrated that when
the centers-of-mass of consecutive distribution patterns are equidistant, the wa-
ter distribution is likely to be the optimal that can be achieved under the major
constraints of the system.
75:03F-045
RESPONSE OF TWO PEANUT CULTIVARS TO IRRIGATION AND KYLAR,
Corbet, D.W., Rhoads, F.M.
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Ag Research Center, Marianna, FL 32446.
Agronomy Journal, Vol. 67, No. 3, p 373-376, May-June 1975. 1 fig, 4 tab, 10 ret.
Descriptors: *Peanuts, Irrigation, Irrigation practices, Irrigation effects,
Crop production, Crop response, Tensiometers.
With improved yields resulting from new cultivars and production practices,
gation of peanuts is receiving increased attention. The objective of this study
was to measure the response of two peanut cultivars to soil-water management in
the plow layer and to the growth regulator Kylar. Tensiometers were utilized to
schedule irrigations for treatments in which soil moisture tension in the plow lay-
er (20 cm) was maintained below 1 bar. In one treatment, plant wilt at midday
was used as an indicator for irrigation. A plant growth regulator, Kylar, was
applied in some treatments to reduce vegetative development. Total pod production
of both cultivars was increased with irrigation, especially in dry seasons.
75:03F-046
DIFFERENTIAL EFFECT OF BERMUDA AND BAHIAGRASSES ON SOIL CHEMICAL CHARACTERISTICS,
Tan, K.H., Beaty, E.R., McCreery, R.A. , Jones, J.B.
Georgia University, Athens, GA 30602. Dept. of Agronomy.
Agronomy Journal, Vol. 67, No. 3, p 407-411, May-June 1975. 5 fig, 2 tab, 20 ref.
Descriptors: *Grasses, *Forage grasses, *Forages, *Organic matter, Crop response,
Soil properties, Soil chemistry, Nitrogen, Fertilization.
The use of bermudagrass and bahiagrass has attracted considerable research atten-
tion with respect to forage production. Little information is available on the
influence of these grasses on soil properties and a direct comparison to effective-
ly estimate the differential effect of bermudagrass and bahiagrass on major soil
chemical properties following 4 years of clipping and N fertilizers treatments.
A randomized split plot experiment was carried out in three replicates using a
montevallo soil planted with several bermudagrass and bahiagrass varieties, receiv-
ing annual application of 0, 224, and 672 kg N per ha from 1967 to 1970. In 1971
herbage and soil samples were collected for yield and chemical analysis. The
results indicated the absence of differences in the effects of the grasses on soil
pH, N, P, K, and Ca, but there were differences in organic matter contents.
75:03F-047
MINIMAL LEACHING WITH VARYING ROOT DEPTHS OF ALFALFA,
Bernstein, L. , Francois, L.E., Clark, R.A.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 112-115 January-
February 1975. 3 fig, 2 tab, 5 ref.
Descriptors: *Leaching, *Alfalfa, Salinity, Lysimeters, Return flow, Saline
water, Crop response, Salt tolerance.
Alfalfa was grown in greenhouse lysimeters with soil depths of 60, 120, and 180 cm
to determine whether rooting depth affected tolerance to the low leaching percen-
tage of 6.25. Salinities of the drainage waters averaged about 6 mmho/cm water.
Steady-state salinity profiles were maintained for 3 years. Yields with the more
saline water averaged 23% less than those of the controls, in good agreement with
previous findings, but were not significantly affected by lysiraeter depth. Water
requirements and uptake of chloride and sodium were only slightly affected by
lysimeter depth. Water requirements and uptake of chloride and sodium were only
slightly affected by lysimeter depth. Salinity profiles with maximum salinities
of 26 mmho/cm in the soil water can, therefore, be compressed into as little as a
60-cm depth with no greater effects on yield or salt uptake by the crop than those
obtained with salinity profiles extended over 120 or 180 cm.
75:03F-048
EFFECT OF DEW ON LEAF WATER POTENTIALS AND CROP RESISTANCES IN A PASPALUM PASTURE,
Kerr, J.P., Beardsell, M.F.
D.S.I.R., Parmerston North, New Zealand.
Agronomy Journal, Vol. 67, No. 5, p 596-599. September-October 1975. 3 fig,
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28 ref, 1 append.
Descriptors: *Dew, *Pastures, *Pasture management, Evapotranspiration, Agricul-
ture, Crop response.
Opportunities for comparing the water status of crops when the presence or absence
of dew is the main environmental variable are rare. This paper reports the results
of such a comparison made on successive days on a paspalum pasture. Leaf water
potentials were measured with a pressure chamber, and the energy balance method
was used to determine evapotranspiration. Crop resistances were calculated from
the micrometeorological data. The presence of dew halved the early morning crop
resistances. The paspalum pasture did not appear to exercise stomatal control
over evapotranspiration until most of the dew had evaporated.
75-.03F-049
SOYBEAN YIELDS AND LANCE NEMATODE POPULATIONS AS AFFECTED BY SUBSOILING, FERTILITY,
AND NEMATICIDE TREATMENTS,
Parker, M.B., Minton, N.A., Brooks, O.L., Perry, C.E.
Agricultural Research Service, U.S. Department of Agriculture, Tifton, GA
Agronomy Journal, vol. 67, No. 5, p 663-666, September-October 1975. 1 fig, 5 tab,
13 ref.
Descriptors: *Soybeans, *Crop response, *Nematodes, Fertilization, Nematicides,
Soil compaction, Crop production.
Soil compaction, nematode damage, and fertility problems occurring singly and in
combination appear to be responsible for low yields of soybeans in some Coastal
Plain soils. This study was designed to determine if these conditions could be
corrected with certain fertility treatments, subsoiling, and a nematicide.
75:03F-050
RESPONSE CURVES OF VARIOUS TURFGRASSES TO APPLICATION OF SEVERAL CONTROLLED-RELEASE
NITROGEN SOURCES,
Volk, G.M., Horn, G.C.
Florida University, Department of Soil Science.
Agronomy Journal, Vol. 67, No. 2, p 201-204, March-April 1975. 6 fig, 9 ref.
Descriptors: *Turf, *Turf grasses, *Nitrogen, *Fertilizers, Fertilization, Ureas,
Crop response, Crop production.
Responses of turfgrasses to eontrolled-release N sources, especially the newer
materials have not been adequately evaluated under field conditions. This study
obtained N time-release curves as measured by clippings taken periodically after
the initial response to readily available N such products contain had subsided.
Materials were surface-applied once, or at widely spaced intervals, to six dif-
ferent tuffgrasses. Three to 4-day growth clippings were taken periodically to
assess current N uptake rate against that from a standard treatment consisting of
a continuous, uniform, weekly application of NH4N03.
75:03F-051
CORN YIELD AND NUTRIENT UPTAKE AS AFFECTED BY WATER-TABLE DEPTH AND SOIL SUBMER-
GENCE,
Chaudhary, T.N., Bhatnagar, V.K., Prihar, S.S.
Punjab Agricultural University, Ludhiana, India.
Agronomy Journal, Vol. 67, No. 6, p 745-749, November-December 1975. 4 fig, 4
tab, 16 ref.
Descriptors: *Water table, *Corn, *Nutrients, Irrigation, Drainage, Crop response,
Fertilization.
Crops are affected by fluctuations in the water table by seasonal rainfall and
soil submergence during growth. A better understanding of their response will
117
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help us to optimize drainage and irrigation. Response of irrigated corn to (i)
four static water-table depths (60, 90, 120, and 150 cm) as affected by the grow-
ing-season rainfall and (ii) single or repeated submergence for 1 to 6 days was
studied in 58-cm diam by 183-cm long metal barrels using silt loam soil during
1971 and 1972. Crop response to water-table depths varied with rainfall during
growth. In a wet year, water table at the 120-cm depth gave the highest and that
at the 60-cm depth the lowest yield. In a relatively dry year, yield was highest
with water tables at 60 and 90-cm depths and decreased with deeper water tables.
It is indicated that a water table at 120-cm depth is desirable for corn.
75:03F-052
PHOSPHORUS UPTAKE BY SOYBEANS AS INFLUENCED BY MOISTURE STRESS IN THE FERTILIZED
ZONE,
Marais, J.N., Wiersma, D.
Fort Hare University, South Africa.
Agronomy Journal, Vol. 67, No. 6, p 777-781, November-December 1975. 5 fig, 14
ref.
Descriptors: *Soil moisture, *Phosphorus, *Soybeans, *Moisture stress, Irriga-
tion, Irrigation effects, Crop response.
Reports on the effect of soil moisture stress on plant uptake of P have been con-
flicting. The effect of the dynamic variation in soil moisture on P uptake by
soybeans was studied in vivo. A split-root technique with plants grown in 3 liter
containers in the greenhouse was used whereby moisture stress was localized in
the zone having the only source of P for the roots, while water and P-free nutri-
ents were supplied through the other portion of the root system. The procedure
minimized the effect of plant-water deficit.
75:03F-053
YIELD AND QUALITY OF CORN AND GRAIN SORGHUM GRAIN AND RESIDUES AS INFLUENCED BY
N FERTILIZATION,
Perry, L.J.Jr., Olsen, R.A.
Nebraska University, Lincoln.
Agronomy Journal, Vol. 67, No. 6, p 816-818, November-December 1975. 3 tab, 12
ref.
Descriptors: *Grain sorghum, *Crop response, *Corn, *Nitrogen, *Fertilizers,
*Fertilization, Crop production.
Crop residues of grain sorghum and corn have attracted attention as an alternate
economical forage resource for livestock utilization. There are little data avail-
able on agronomic production factors affecting yield and quality of crop residues.
We evaluated the effect of rate and time of N fertilization on irrigated corn
and grain sorghum grain and residue yields, grain N content, and forage quality
of the residues.
75:03F-054
ADVECTION MODIFICATION OF THE PRIESTLEY AND TAYLOR EVAPOTRANSPIRATION FORMULA,
Jury, W.A., Tanner, C.B.
California University, Riverside CA 92502
Agronomy Journal, Vol. 67, No. 6, p 840-842, November-December 1975. 2 fig, 7 ref.
Descriptors: *Advection, *Evapotranspiration, *Evaporation.
The empirical formula of Priestley and Taylor (1972) relating the evapotranspiration
from a well-watered surface to the net radiation and a function of the air temper-
ature is modified to include a saturation deficit term to account for high local
advection. The model is tested on two seasons of daily evapotranspiration measure-
ments over irrigated potatoes resulting in good agreement and a substantial im-
provement over the unmodified formula. Alfalfa measurements are also represented
well by the model, but no better than by the Priestley-Taylor formula calibrated
during a period of high advection.
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75:03F-055
EFFECT OF IRRIGATION AND NITROGEN ON THE DRY MATTER AND CRUDE PROTEIN YIELDS OF
'PANGOLA1 DIGITGRASS,
Byam, L., Gumbs, F.A.
West Indies University, St. Augustine, Trinidad. Dept. of Soil Science.
Agronomy Journal, Vol. 67, No. 3, p 365-369, May-June 1975. 6 tab, 14 ref.
Descriptors: *Grasses, *Forage grasses, Irrigation effects, Irrigation, Crop
response, Crop production, Dry farming, Dry seasons, Fertilizers, Fertilization,
Nitrogen.
In Trinidad, West Indies, a dairy industry is being developed on Piarco fine sand/
fine sandy loam soil. The soil is physically and chemically poor. The cattle
obtain most of their food supply by grazing 'Pangola' digitgrass. There is an
urgent need to increase grass production on this soil type. Inadequate water
supply in the dry season limits grass production. Previous fertilizer trials with
Pangola digitgrass on this soil type have indicated that N fertilizer is likely to
give better yield response than P, K, or Ca. This trial was therefore conducted
to determine the irrigation-N management for wet and dry season production of
Pangola digitgrass on this soil at adequate levels of P and K.
75:03-056
NUTRIENT DILUTION-ANTAGONISM EFFECTS IN CORN AND SNAP BEANS IN RELATION TO RATE
AND SOURCE OF APPLIED POTASSIUM,
Terman, G.L., Allen, S.E., Bradford, B.N.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 680-685, July-
August 1975. 6 fig, 2 tab, 12 ref.
Descriptors: *Corn, *Beans, *Crop response, *Potassium, Nutrients, Fertilization,
Crop production.
Greenhouse pot experiments were conducted to compare responses of corn and snap
beans to 0 to 1,600 mg of K/pot as KNO3, KC1, and K2SO4 on K-deficient soils (3 kg
of soil/pot). Marked responses were obtained to applied K, which were similar
among sources, except for a toxic salt effect of 1,600 mg of K as KC1. Marked
reciprocal K-N, K-P, K-Ca, and K-Mg relationships with yield response to rates of
applied K were attributed to both dilution and ion antagonism.
75:03F-057
INCREASING WATER USE EFFICIENCY THROUGH IMPROVED ORIFICE DESIGN AND OPERATIONAL
PROCEDURES FOR SUBIRRIGATION SYSTEMS,
Wilke, O.C., Hiler, E.A.
Texas Water Resources Institute, Texas A & M University, Lubbock, Texas.
Technical Report No. 63, 1975. 37 p, 10 fig, 1 tab, 12 ref.
Descriptors: *Irrigation, *Irrigation systems, *Irrigation efficiency, *Model
studies. Soil-water movement, Subsurface irrigation, Orifice flow, Orifices.
Two mathematical models describing one-dimensional flow were developed. One con-
sidered the consumption of water by roots. For the assumed distribution of the
root consumption with time and depth, the 10-cm (4-in.) deep source provided
better water distribution than did 20-and 30-cm (8-and 12-in.) deep sources. Irr-
igation from zero depth, as in the case of trickle irrigation, appeared to be the
best system for the given conditions. Plugging of emitters by particulate mater-
ials decreased as the cross-sectional area of the emitter opening was increased.
Less than 0.06 atm (1 psig) vacuum had little effect on the flow of emitters
tested. Higher vacuum amounts caused the reopening of plugged orifice emitters,
but caused plugging of labyrinth emitters. Vacuum-induced plugging of labyrinth
emitters resulted from accumulation of silt and fine sand within the flow path.
Operation at higher pressures caused limited flow recovery. A theory was proposed
for determining pressure distributions in drip laterals where water is uniformly
distributed along the lateral's length. The theory provided acceptable design in
two tests. Computer-derived design curves were developed. Because 1000 or more
emitters may be required for subirrigation of each acre, emitters need to be both
inexpensive and resistant to plugging. Four experimental emitters were designed
and constructed. A modification of one microtube emitter is being produced
commercially.
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75:03F-058
CROP PRODUCTION FUNCTION DETERMINATIONS AS INFLUENCED BY IRRIGATION AND NITROGEN
FERTILIZATION USING A CONTINUOUS VARIABLE DESIGN,
Bauder, J.W., Hanks, R.J., James, D.W.
North Dakota State University, Fargo, ND 58102.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1187-1192, November-
December 1975. 3 fig, 6 tab, 16 ref.
Descriptors: *Irrigation, Irrigation effects, *Nitrogen, *Nutrients, Fertilizers,
Fertilization, Crop production. Soil water, Moisture stress.
Continuous variable (CVD) and randomized block, split plot (RBSD) designs were
used to produce data from which production functions were developed relating corn
yield to soil water and nitrogen fertilizer. Data were collected at Logan, Utah
in 1972 and Farmington, Utah in 1973. The CVD water and nitrogen treatments,
respectively, were sequential or continuous and not randomized. The design is com-
pact but has some statistical uncertainty. The CVD had 7 or 8 soil-water (W) levels
and 22 or 24 nitrogen (N) levels compared to 4 W and 5 N levels for RBSD. The area
used for the RBSD was 3 or 4x that used for the CVD. The data analyzed for the
CVD led to the same conclusions as the analysis of the RBSD. The production func-
tion (regression equation) at Logan was different from that at Farmington except
when comparisons were made on a relative basis.
75:03F-059
EFFECT OF LIME ON BORON TRANSPORT TO AND UPTAKE BY COTTON,
Scott, H.D., Beasley, S.D., Thompson, L.F.
Department of Agronomy, University of Arkansas, Fayetteville, AR 72701.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1116-1121, November-
December 1975. 3 fig, 5 tab, 2 equ, 22 ref.
Descriptors: *Boron, *Cotton, *Crop response. Soils, Soil investigations, Soil
chemistry, Moisture stress. Adsorption, Diffusivity, Lime.
Deficiencies of Boron have occurred in cotton grown in coarse textured soils
during periods of moisture stress and in those soils which have been recently
limed. These B deficiencies have generally been attributed to a decrease in soil
B availability to cotton. As a result a greenhouse experiment was conducted to
study (i) the amounts of adsorption and diffusivity rates of B in two silt loams
and (ii) B absorption by cotton grown in pots. Addition of lime increased B
adsorption occurred on the seventh day after its addition but did not differ
appreciably from the one day equilibration time. The adsorption data could not be
accurately described by the Langmuir adsorption equation.
75:03F-060
POTASSIUM IN AN ARID LOESSIAL SOIL: CHANGES IN AVAILABILITY AS RELATED TO CROPPING
AND FERTILIZATION,
James, D.W., Weaver, W.H., Roberts, S., Hunter, A.H.
Utah State University, Logan 84322.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1111-1115, November-
December 1975. 8 fig, 2 tab, 7 ref.
Descriptors: *Potassium, *Fertilizers, *Fertilization, Nutrients, Crop production.
Two K fertilizer experiments were initiated in 1961 in arid central Washington on
a Shano silt loam soil site that had been leveled to accommodate irrigation. The
experiments were continued for 3 years and utilized rates of K fertilizer up to
320 kg K/ha in a randomized complete block design. By 1964 there existed a wide
range of Kst (soil test K) as a result of the fixed random K treatments and partial
exposure of K-deficient subsoils. That year the experiments were altered to com-
pletely randomized designs using both Kst and K fertilizer rates as controlled
variables. The experiments were continued through 1970, providing an evaluation
of the effects of crop management and K fertilization on soil K reserves.
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75:03F-061
INITIAL RELEASE OF NITROGEN FROM UREAFORM UNDER FIELD CONDITIONS,
Hada, A., Kafkafi, U., Peled, A.
Division of Soil Chemistry and Plant Nutrition, Institute of Soils and Water,
Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1103-1105, November-
December 1975. 3 fig, 2 tab, 10 ref.
Descriptors: *Nitrogen, *Nitrite, Nutrients, Crop response, Fertilizers, Fertiliza-
tion, Ureas.
The mineralization of ureaform in the soil has been observed during the three
weeks following application in a small plot of a banana plantation at two different
seasons of the year. In the cooler season ammonium and nitrite accumulated and
persisted for 2 weeks. In the warmer season, only ammonium accumulated during two
days. The rate of mineralization, calculated as first-order reaction, was greater
at the higher temperature, but the rate constants were about 10 times greater in
the field than in previous laboratory experiments. The reasons for this are prob-
ably changes in microbiological activity and mineralization of nitrogen from sources
other than the fertilizer.
75:03F-062
REACTION PRODUCTS OF POLYPHOSPHATES AND ORTHOPHOSPHATES WITH SOILS AND INFLUENCE ON
UPTAKE OF PHOSPHORUS BY PLANTS,
Subbarao, Y.V., Ellis, R. Jr.
Department of Agronomy, Kansas State University, Manhattan, Kansas 66506.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1085-1088, November-
December 1975. 7 fig, 3 tab, 8 ref.
Descriptors: *Phosphorus, *Corn, Crop response, Nutrients, Fertilizers, Fertiliza-
tion, Chemical reactions.
Ammonium polyphosphate and diammonium phosphate were compared as sources of P for
corn in a growth chamber experiment with an alkaline-calcareous soil and a slightly-
acid soil. Reaction products of the two P sources in soils and soil extracts
correlated with results obtained in the growth chamber. Applied P increased dry
weights, uptake of P by the plants, and available soil P in the slightly acid soil.
Ammonium and magnesium orthophosphates, formed as reaction products in the labora-
tory experiments when the two P fertilizer materials were added, should furnish
sufficient P for plant growth.
75:03F-063
EFFECTS OF UNEVEN SPREADING OF FERTILIZER ON CROP YIELDS,
Lutz, J.A. Jr., Jones, G.D., Hawkins, G.W., Hutcheson, T.B. Jr.
Virginia Polytechnic Institute and State University, Blacksburg, VA, Dept. of
Agronomy.
Agronomy Journal, Vol. 67, No. 4, p 526-529, July-August 1975. 3 fig, 7 tab, 5
ref.
Descriptors: *Fertilization, *Fertilizers, *Nutrients, Crop response, Crop
production, Virginia, Corn, Barley, Soybeans, Wheat.
Bulk spreading of fertilizer does not always result in a uniform distribution over
the entire area. The extent to which this distribution affects crop yield is
unknown and should be investigated. As a result, nine experiments were conducted
over a period of several years to determine the effects of uneven distribution
of fertilizer on the yield of corn, barley, soybeans, and wheat. The investiga-
tions were conducted in the three physiographic areas of Virginia. Soil types
varied from thick surface phase sandy loams to a clay loam. Four spread patterns
commonly obtained in farming operations and a no-fertilizer treatment were used.
In 1970, corn on Frederick silt loam and Tatum silt loam responded to fertilization,
but there was no significant differences in yields among spread patterns on
Lodi loam. Significant differences in yields among spread patterns on Davidson
clay loam were observed.
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75:03F-064
EFFECT OF IRRIGATION, LIME, AND FERTILITY TREATMENTS ON THE YIELD AND CHEMICAL
COMPOSITION OF SOYBEANS,
Lutz, J.A. Jr., Jones, G.D.
Virginia Polytechnic Institute and State University, Blacksburg VA. Dept. of
Agronomy.
Agronomy Journal, Vol. 67, No. 4, p 523-526, July-August 1975. 6 tab, 5 ref.
Descriptors: *Soybeans, *Crop response, *Nutrients, *Fertilization, Potassium,
Phosphorus, Irrigation, Irrigation effects.
Data are available on the effects of surface applied plant nutrients on the yield,
quality, oil, and protein contents of soybean seed and on the chemical composition
of the soybean leaves. Very little information is available, however, on the
effects of irrigation and plow sole (30.5 cm) placement of plant nutrients on
these same plant characteristics. In order to determine the effects of irrigation
and plow sole placement of P, K, lime, and micronutrients on the quality, yield,
oil, and protein contents of soybean seeds and on the chemical composition of
the leaves, a field experiment was conducted for 3 consecutive years.
75:03F-065
EFFECT OF METHOD OF NITROGEN APPLICATION ON CORN (ZEA MAYS L.) GROWN ON IRRIGATED
SANDY SOILS,
Rehm, G.W., Wiese, R.A.
Northeast Station, University of Nebraska, Concord.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1217-1220,
November-December 1975. 1 fig, 2 tab, 10 ref.
Descriptors: *Nitrogen, *Nutrients, *Fertilizers, Fertilization, Corn, Crop
response, Irrigation,/Leaching.
Studies were conducted in 1970 and 1972 to determine the influence of method of
nitrogen application on corn production on irrigated, sandy soils. Conventional
preplant and sidedress treatments were compared to situations where either pre-
plant or sidedress applications were supplemented with added N in the irrigation
water. Grain yields were recorded and the N03(-)-N distribution to 150 cm in the
soil profile was measured at the end of the growing season. The influence of
method of application on corn yields was related to the textural profile of the
soil. For a sandy soil with no accumulation of fine-textured material, the appli-
cation of N with the irrigation water increased grain' yields. Also, the corn
crop recovered a higher proportion of the applied N when some fertilizer N was
added with the irrigation water. For a soil type characterized by an accumulation
of fine textured material at 50-70 cm below the surface, method of N application
had no influence on yield since the.downward movement and loss of N03(-)-N was
restricted by the layer of fine-textured material. The data show that the
application of a portion of the N fertilizer requirement with the irrigation water
should be a recommended practice for corn production on sandy soils having no
accumulation of fine-textured material.
75:03F-066
ON A DERIVABLE FORMULA FOR LONG-WAVE RADIATION FROM CLEAR SKIES,
Brutsaert, W.
Cornell University, Ithaca, New York. School of Civil and Environmental Engineer-
ing.
Water Resources Research, Vol. 11, No. 5, p 742-744, October 1975. 1 fig, 1 tab,
16 ref.
Descriptors: *Radiatioh, Mathematical studies, Mathematics.
A derivation is presented for the effective atmospheric emissivity to predict
downcoming long-wave radiation at ground level under a clear sky and for a nearly
standard atmosphere. The results are in good agreement with those obtainable
with empirical formula based on water vapor pressure and temperature. However,
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the proposed formulation has the advantage that its simple functional form is
based on physical grounds without the need for empirical parameters from radiation
measurements. Also, in contrast to the empirical equations, it may be adjusted
in a simple way to reflect changes in climatic and atmospheric conditions.
75-.03F-067
WATER LOSSES FROM AN IRRIGATED SOYBEAN FIELD BY DEEP PERCOLATION AND EVAPOTRANS-
PIRATION,
Carvallo, H.O., Cassel, O.K., Bauer, A.
North Dakota State University, Fargo, ND. Department of Soil Science.
Water Resources Research, Vol. 11, No. 2, p 267, April 1975. 2 fig.
Descriptors: *Soybeans, Irrigation, Irrigation effects, Return flow, Evatrans-
piration, North Dakota, Crop production.
Soil-water flux below the root zone of a soybean crop was measured in the field
at Oakes, North Dakota, during the crop season in 1972 for four water treatments.
Amounts of 0, 30.6, 38.1, and 47.0 cm of water were applied in addition to the
19.5-cm rainfall occurring during the growing season to treatments W-l, W-2,
W-3, and W-4, respectively. Specific in situ unsaturated hydraulic conductivity
for each plot of the Maddock sandy loam soil and hydraulic gradients measured
with tensiometers in the field during the growing season were used to compute the
soil-water flux.
75:03F-068
FIELD CHANNELS: A KEY TO BETTER INDIAN IRRIGATION,
Easter, K.W.
Minnesota Univ., St. Paul, Minnesota. Dept. of Agricultural and Applied Economics.
Water Resources Research, Vol. 11, No. 3, p 389-392, June 1975. 3 tab, 8 ref.
Descriptors: Irrigation, Irrigation effects. Surface irrigation. Flood irrigation,
Irrigation systems.
Two different programs which attempted to improve water use and management were
evaluated in eastern India. The improvement was through the installation of
field channels in existing flood irrigation projects. The channels gave farmers
better control over water on each field. The analysis highlights the importance
of technically trained people and low-cost project designs in making projects via-
ble. Annual net returns of 300-350 rupees per acre were obtained in the Sambalpur
villages with investment costs of only 34 rupees per acre. The contrasting pilot
project in Raipur had a much lower profit potential due to high investment costs.
The analysis adds support to the proposition that India should spend more public
funds on modest improvements in existing flood irrigation systems and much less
on large new irrigation projects.
75:03F-069
THE EFFECTS OF STREAMFLOW VARIATION ON PRODUCTION AND INCOME OF IRRIGATED FARMS
OPERATING UNDER THE DOCTRINE OF PRIOR APPROPRIATION,
Anderson, R.L.
Colorado State University, Ft. Collins, CO 80523. Economics Department. United
States Dept. of Agriculture, Natural Resource Economics Division, Economic
Research Service.
Water Resources Research Vol. 11, No. 1, p 15-22, February 1975. 5 fig, 11 tab,
4 ref.
Descriptors: Irrigation, Irrigation practices, Streamflow, Prior appropriation,
Water supply, Runoff.
Many irrigated farms dependent upon varying streamflow frequently encounter periods
of inadequate water supply because streamflow is inadequate to serve all water
rights. Streams fed by mountain snowmelt exhibit sharply peaked hydrographs.
During the peak runoff period most water rights can be served. Thereafter stream-
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flow declines rapidly, and many of the later water rights are denied water.
Farms that are prohibited from diverting water suffer reduction in crop yields
and income. To get the most benefit from varying flow, streams must be closely
monitored so that as many rights as possible can be served with the original flow
and the return flow that occurs.
75:03F-070
EFFECTS OF SOIL-MOISTURE REGIMES ON THE GROWTH OF BARLEY,
Day, A.D., Thompson, R.K.
Arizona University, Tucson, Arizona. Agricultural Experiment Station.
Agronomy Journal, Vol. 67, No. 3, p 430-432, May-June 1975. 4 tab, 9 ref.
Descriptors: *Moisture stress, *Soil water, *Barley, Crop response, Irrigation,
Irrigation effects.
Effects of soil-moisture stress at three different stages of growth (jointing,
flowering, and dough) on grain yield, grain quality, and plant growth of Spring
barley planted in November were studied under the field conditions at Mesa,
Arizona. The experiment was conducted to determine the limitations to irrigation
water conservation in a semiarid environment. Four by four Latin square designs
were used to compare four irrigation treatments. Effects of soil-moisture stress
for 7 days at the jointing, flowering, and dough stages of growth and/or until
100% of available water in the first 3 feet of soil was depleted were compared with
plants not stressed.
75:03F-071
OPTIMIZATION OF WATER USE EFFICIENCY UNDER HIGH FREQUENCY IRRIGATION — I.
EVAPOTRANSPIRATION AND YIELD RELATIONSHIP,
Howell, T.A., Hiler, E.A.
New Mexico State University, Las Cruces, Agricultural Engineering Department.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 5,
p 873-878, September-October 1975. 2 fig, 5 tab, 6 equ, 20 ref.
Descriptors: *Irrigation, *Irrigation efficiency, *Irrigation practices, Irriga-
tion systems, Evapotranspiration, Crop response, Grain sorghum, Irrigation
effects, Lysimeters, Moisture stress.
An experiment was conducted in 1973 to determine the sensitivity of grain sorghum
to water deficits in three selected growth stages under high frequency irrigation.
Field lysimeters containing undisturbed soil cores were utilized. Rainfall was
removed as a variable by an automatic shelter system. Irrigation treatments
consisted of a well-watered control, a variable level of deficit in all three
growth periods (SDI treatment), and six additional treatments were irrigated three
times per week. Measurements were made to determine irrigation amount, storage
depletion, and drainage amount; hence total crop water use could be determined.
Three empirical yield models (two multiplicative type and one additive type) were
compared to the experimental data. All of these models were quite similar in
formulation and represented the experimental data accurately within the range of
the data.
75:03F-072
DESIGN OF IRRIGATION RUNOFF RECOVERY SYSTEMS,
Stringham, G.E., Hamad, S.N.
Utah State University, Logan, Utah. Department of Agricultural Engineering and
Irrigation Engineering.
Journal of the Irrigation and Drainage Division, Vol. 101, No. IR3, p 209-219,
September 1975. 2 fig, 16 equ, 5 ref, 1 append.
Descriptors: Irrigation, Furrow irrigation, Surface irrigation, Return flow,
Water conservation, Irrigation practices, Irrigation efficiency, Irrigation sys-
tems .
Adequate furrow irrigation requires runoff and the runoff can be controlled by
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using an irrigation runoff recovery system. Such systems have been designed in
the past and used successfully. However, one of the problems encountered has been
the adjustment of set size and furrow discharge rates to accommodate the intermit-
tant flows from recirculating pumps. A design technique has been developed that
permits a constant inflow to all furrows throughout the entire irrigation, requires
changes in set size only twice, permits using a constant discharge from the pump
once it is turned on, and uses all the water applied to the field, i.e., there is
no net runoff from the field. This is accomplished by irrigating the entire first
set from the inflow water and collecting the runoff in a storage reservoir. All
of the remaining sets, except the last one, are irrigated by both the supply
stream and the runoff water, recirculated by pump, and the last set is irrigated
entirely by pumped runoff water. At the end of the last set, no water should re-
main in the storage reservoir. The technique provides ways to determine the number
of furrows in each set, the volume of storage required in the storage reservoir,
and the recirculating pump flow rate. This design technique will be an aid to
irrigation engineers in the design of the IRRS.
75:03F-073
HERBIGATION,
Pischbach, P.E.
Nebraska University, Agricultural Engineering and Extension Irrigation, Lincoln,
Nebraska.
Irrigation Journal, Vol. 25, No. 3, p 22-24, May-June 1975.
Descriptors: Herbicides, Irrigation, Irrigation practices, Irrigation systems,
Irrigation efficiency.
Herbigation? Yes, a new-coined word. What is it? Herbigation is the science of
applying herbicides through an irrigation system. It's a new way to save food
production costs and labor.
75:03F-074
COMPUTER IRRIGATION,
Irrigation Journal, Vol. 25, No. 5, 2 pages, September-October 1975.
Descriptors: Irrigation, Scheduling, Computers, Computer programs. Irrigation
practices.
When to irrigate and how much water to use on crops are decisions which will be
made by computer during the current growing season for a test group of coopera-
ting farmers in western and southeastern Colorado. The farmers are part of a
computer-controlled irrigation program being conducted by the U.S. Interior Depart-
ment's Bureau of Reclamation. Program Coordinator Jerry Buchheim is in charge df
the project, which is monitored by the bureau's giant Control Data CYBER 74 com-
puter at the Federal Center in Denver.
75:03F-075
HERBICIDES AND SURFACE IRRIGATION-DO THEY MAKE A TEAM?,
Schleicher, G.
The Webb Company, 1999 Shepard Road, St. Paul, MN 55116
Irrigation Age, Vol. 9, No. 5, 2 pages, February 1975.
Descriptors: *Herbicides, *Surface irrigation, *Furrow irrigation, Irrigation,
Irrigation practices.
Herbigation through center pivot sprinkler irrigation works. That's the consen-
sus of a growing number of irrigation specialists and irrigating farmers who have
put the concept to use on a surprising variety of crops. But what about the sur-
face irrigator, the operator who uses gated pipe or an open ditch to deliver water
to his fields? Can herbicides be applied as efficiently at ground level as they
are through a sprinkler nozzle? That question has been the target of several pri-
vate and university studies in the last year or two. And while conclusive results
are still somewhat sketchy, it's beginning to look like surface herbigation may
eventually take a place in the irrigating farmer's stack of management tools.
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75:03F-076
HE'S AUTOMATING DEAD LEVEL IRRIGATION,
ROSS, R.
The Webb Company, 1999 Shepard Road, St. Paul MN 55116
Irrigation Age, Vol. 9, No. 6, 3 pages, March 1975.
Descriptors: *Surface irrigation, *Furrow irrigation, Irrigation, Irrigation
practices, Irrigation efficiency.
Dana Fisher is an enthusiastic innovator. Almost before researchers have put
their tentative stamp of approval on an applicable development, it's at work in a
big way on Fisher's 6,000-acre Palo Verde Valley farm. It's that type of non-
traditionalism that created Fisher's open-ditch system of automated irrigation on
dead level fields. Eye-opening labor and water savings triggered the 160-acre
development.
75:03F-077
MAKING SURFACE IRRIGATION WORK WITH AUTOMATION,
Alleman, R.
Irrigation Age, Vol. 9, No. 7, p 38-39, April 1975.
Descriptors: *Surface irrigation, *Furrow irrigation, Irrigation, Water conserva-
tion, Irrigation efficiency, Irrigation systems.
Nebraska farmers Ed Thieszen and Ted Regier have moved to irrigation systems that
cut labor to the minimum, save water, and may increase corn yields. Sound like
new sprinklers? Wrong. Both have installed automatic surface systems.
75:03F-078
A NEW TECHNIQUE FOR CONSERVING WATER,
Humpherys, A.
Idaho
Irrigation Age, Vol. 9, No. 7, p 24-25, April 1975.
Descriptors: *Water conservation, Irrigation, Irrigation systems, Irrigation
efficiency, Irrigation practices.
As our knowledge of soils and plants increases and as we learn more about the
effects of the field environment and cultural treatments on plant growth and
production, we will need to modify present tillage, irrigation, and cultural prac-
tices to take advantage of new concepts. A practice getting recent attention con-
sists of using short, frequent irrigations which vary from daily irrigations to
irrigating every two or three days.
75:03F-079
SPRINKLERS FOR MULTIPLE USE,
Hagood, M.
Washington
Irrigation Age, Vol. 9, No. 8, p 11-12, May-June 1975.
Descriptors: Sprinkler irrigation, Irrigation, Irrigation systems, Irrigation
practices, Fertilization.
Multiple use for full utilization of our natural resources has been popular for
several years. The multiple use concept for irrigation systems can also be bene-
ficial. Besides nonagricultural uses of sprinkler systems, there are many produc-
tion aspects which provide potentially better utilization. These include the
fertilizer, soil amendment and pesticide application, and climate control. And,
although single line systems can be used for purposes other than irrigation, the
real dividends come when systems are automated. Solid sets and center pivots,
particularly, lend themselves to sophisticated and extra dividend benefits. Mul-
tiple purpose systems make it possible to save labor, material, and energy by
requiring fewer trips across the field with machinery and by timely chemical appli-
cation.
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75:03F-080
THE IRRIGATOR'S COUNSELOR,
Schleicher, G.
The Webb Company, 1999 Shepard Road, St. Paul MN 55116.
Irrigation Age, Vol. 10, No. 1, p 20-26, October 1975.
Descriptors: Energy conservation, Water conservation, Irrigation, Scheduling,
Sprinkler irrigation.
This past summer, over 400 High Plains farmers improved their fertility programs,
upgraded their irrigation efficiency, and reduced weed, insect and disease prob-
lems without spending a single extra hour in the field. How? By hiring a profes-
sional consulting firm at McCook, Nebraska, to do their worrying for them.
75:03F-081
IRRIGATION SCHEDULING FOR ENERGY AND WATER CONSERVATION,
Heermann, D.F.
Agricultural Research Service-USDA Fort Collins, Colorado.
Sprinkler Irrigation Association, 1975 Annual Technical Conference Proceedings,
p 7-13, Hyatt-Regency Hotel, Atlanta, Georgia, February 23-25, 1975. 2 fig,
14 ref.
Descriptors: *Water conservation, *Energy conservation, *Scheduling, Sprinkler
irrigation, Surface irrigation.
Many irrigation scheduling schemes have been developed to help the irrigator
conserve water and increase yields. The more complex schemes have been shown to
conserve considerable amounts of water and energy. However, even the simpler
schemes must not be overlooked since they also are good management tools. The
benefits of irrigated agriculture in food production will undoubtedly force con-
tinued irrigation development throughout the world.
75:03F-082
THE FUTURE OF AUTOMATED SPRINKLER IRRIGATION SYSTEMS,
Splinter, W.E.
Nebraska University, Agricultural Engineering Department, Lincoln, Nebraska.
Sprinkler Irrigation Association, 1975 Annual Technical Conference Proceedings,
p 42045, Hyatt-Regency Hotel, Atlanta, Georgia, February 23-25, 1975. 8 ref.
Descriptors: *Sprinkler irrigation, *Automatic control, *Automation, Irrigation,
Irrigation practices, Irrigation efficiency.
Sprinkler irrigation, especially automated forms of sprinkler irrigation, will
play a key role in supplying the U.S. with adequate food resources to meet the
expanding demands internally and to provide diplomatic and balance-of-trade im-
pact on the international scene. As menial labor to provide shovel work for irri-
gation becomes increasingly scarce, there will be continued pressures to increase
initial investment to automate irrigation.
75:03F-083
DRIP IRRIGATION PROGRESS AND PROBLEMS,
Aljibury, F.K.
California University, Cooperative Extension, Parlier, CA
Sprinkler Irrigation Association, 1975 Annual Technical Conference Proceedings,
p 46-47, Hyatt-Regency Hotel, Atlanta, Georgia, February 23-25, 1975.
Descriptors: Irrigation, Irrigation methods, Irrigation practices. Water conser-
vation.
Most drip irrigation installations in California and elsewhere, were made to solve
specific problems of water cost, water shortage, soil conditions, labor expense
and automated water delivery. The acceptance of this method would have been
limited, however, without favorable crop response, production, and favorable costs.
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Field experience shows that drip irrigation is most advantageous under conditions
marginal for other methods of water application.
75:03F-084
DRIP IRRIGATION FILTRATION PROBLEMS AND RESEARCH,
Wilson, D.L.
Controlled Water Emission Systems, El Cajon, California.
Sprinkler Irrigation Association, 1975 Annual Technical Conference Proceedings,
p 51-57, Hyatt-Regency Hotel, Atlanta, Georgia, February 23-25, 1975. 4 ref.
Descriptors: Irrigation water, Irrigation, Irrigation systems, Filtration,
Filters, Water quality.
One of the major concerns in drip irrigation is filtration. It is fairly well
agreed that proper filtration makes the difference between an effective drip
installation and one that is ineffective with many problems and poor efficiency.
In this paper, the drip filtration problem is examined and defined. Existing
equipment and processes to treat the filtration requirement are reviewed. Some
of the equipment and processes under development are discussed.
75:03F-085
"TUNING IN" SAVES WATER, BOOSTS YIELDS ON SANDY SOILS,
ROSS, R.
Irrigation Age, A Webb Publication.
Irrigation Age, Vol. 10, No. 3, November-December 1975. p 18-20.
Descriptors: Irrigation, Irrigation efficiency, Irrigation water, Sprinkler
irrigation, Scheduling.
Any irrigator who can get more yield while using less water is on the right
track to higher profits. Bill Condon, Sterling, Colorado rancher/farmer, has
been in the desired position for three years. By using an irrigation scheduling
program developed by Dr. Dale Heermann, and other Agricultural Research Service
colleagues, stationed at Ft. Collins, Colorado, Condon has been able to get con-
sistent yield increases (yields are now between 150 and 160 bushels of corn per
acre). Water usage has dropped by about 6 inches per year, and that, says Condon,
"adds a year of life to a center pivot every 5 years because we save about 7
revolutions per year."
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Section XVI
WATER QUANTITY MANAGEMENT AND CONTROL
CONTROL OF WATER ON THE SURFACE (GROUP 04A)
75:04A-001
SOLUTIONS FOR UNCONFINED NON-DARCY SEEPAGE,
Volker, R.E.
James Cook University of North Queensland, Townsville (Australia). Department
of Engineering.
Journal of the Irrigation and Drainage Division, Proceedings of American Society
of Civil Engineers, Vol. 101, No. iRl, Proceedings Paper 11203, p 53-65, March
1975. 8 fig, 1 tab, 17 ref, 2 append.
Descriptors: *Porous media, *Darcys law, *Model studies, Digital computers,
Hydraulic conductivity, Reynolds number, Wells, *Seepage, Transmissivity,
Permeameters, Flow nets, Drainage, Rock fill, Boundary processes, Piezometers,
Head loss.
Numerical and experimental studies of non-Darcy flow in porous media were ex-
amined. Laboratory experiments with a screened gravel included radial flow
to a simulated well and a sector and two-dimensional flow through a bank with
vertical sides in a flume. Permeameter tests on the gravel were used to esti-
mate coefficients in the nonlinear relation between head loss and velocity.
Results were presented of analyses performed by a finite difference solution
of the appropriate partial differential equation boundary value problem. The
flow nets and discharges obtained were compared with the experimental results
and the corresponding solutions for Darcy flow.
75:04A-002
ESTIMATING LAND USE CHARACTERISTICS FOR HYDROLOGIC MODELS,
Gluck, W.R. and McCuen, R.H.
Rummel, Klepper and Kahl, Baltimore, Maryland.
Water Resources Research, Vol. 11, No. 1, p 177-179, February 1975. 2 tab,
9 ref.
Descriptors: *Land Classification, *Land use, *Urban mapping, *Model studies,
Watersheds(Basins), Rainfall-runoff relationships, Urban hydrology, Suburban
areas, Hydrology, Equations, *Estimating.
Equations for estimating land use characteristics used in hydrologic models
were presented. The method presented was intended as a reliable alternative
to the more costly, time-consuming process of aerial photography interpretation.
Application of the equations permits prediction of future land use configurations.
Data input takes the form of demographic characteristics (e.g., population den-
sity of housing density) which is frequently available from planning agencies
or others.
75:04A-003
PARAMETERS FOR ESTIMATING ANNUAL RUNOFF AND SOIL LOSS FROM AGRICULTURAL LANDS
IN RHODESIA,
Elwell, H.A., and Stocking, M.A.
Agricultural Engineering Centre, Salisbury (Rhodesia).
Water Resources Research, Vol. 11, No. 4, p 601-605, August, 1975. 2 fig, 4 tab,
12 ref.
Descriptors: *Runoff, *Rainfall-runoff relationships, *Runoff forecasting,
*Soil erosion, *Semiarid climates, Africa, Subtropic, Agricultural runoff,
Rainfall, Rainfall disposition, Soil conservation, Rainfall intensity, Vege-
tation effects, Impact(Rainfall), Grasslands, Cultivation, Arid Climates.
Cumulative values of rainfall energy, momentum, and depth were investigated as
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predictors of annual soil loss and runoff from selected arable and grazing land
field trial plots. Energy parameters were the most accurate predictors of soil
loss from bare soils, explaining 96.4% of the variation in results from a clay
loam and 80.0% from a sandy soil. Momentum, energy, and precipitation depth
parameters were all close in their prediction of soil loss from the vegetated
plots or as predictors of runoff from both bare and vegetated conditions,
and consequently, precipitation depth parameters were selected as being the most
practical for soil loss and runoff estimation under the conditions investigated.
Percentage vegetal cover was shown to be an additional important variable on
grassland.
75:04A-004
SCREENING MODEL FOR CONJUNCTIVE-USE SYSTEMS,
Hamdan, A.S., Meredith, D.D.
Harza Engineering Company, Chicago, Illinois.
Journal of the Hydraulics Division Vol. 101 No. HY10 p 1343-1355. October 1975.
2 fig, 5 tab, 16 ref, 2 append.
Descriptors: *Model studies, Groundwater, Surface waters, Planning, Simulation
analysis.
This paper presents a preliminary screening model for use in planning conjunctive-
ly operated ground-water and surface water systems. The model is a minimum
cost flow network model for which the out-of-kilter algorithm can be used as a
solution technique. To present the model and computational strategy, an example
problem is formulated and analyzed to illustrate how the model can be used to
answer planning and management queries.
75:04A-005
AUTOMATED VALVES FOR SURFACE IRRIGATION PIPELINES,
Humpherys, A.S., Stacey, R.L.
Agricultural Research Service, Kimberly, Idaho. Snake River Conservation Research
Center.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 101, No. IR2, p 95-109, June, 1975. 15 fig, 3 ref, append.
Descriptors: *Hydraulic valves, *Distribution systems, *Irrigation engineering,
*Surface irrigation, *Flow control, Automation, Irrigation systems, Pipes, Water
distribution(Applied), Irrigation practices. Irrigation design, Irrigation oper-
ation and maintenance, Conveyance structures, Irrigation, Water delivery,
Operating costs, Water control, Irrigation efficiency, Design criteria.
Automatic irrigation valves have been developed to control the discharge from
a field pipeline turnout into either gated pipe or directly into irrigation bor-
ders. Design information for 6-inch, 8-inch and 10-inch valves is given. Two
types of water-inflatable bladders are used to open and close the valves which
are designed to operate with water from the irrigation pipeline at pressures
up to approximately 12 pounds per sq inch. Small 3-inch pilot valves, operated
by a 3 volt dc battery powered motor, are used to control opening and closing
of the irrigation valves. This motor/pilotvalve unit can be used with mechanical
and electronic timers, commercial irrigation controllers, or radio transmitter/
receiver units.
75:04A-006
PORTABLE, ADJUSTABLE FLOW-MEASURING FLUME FOR SMALL CANALS,
Replogle, J.A.
U.S. Water Conservation Laboratory, 4331 East Broadway, Phoenix, AZ 85040.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 25 p, 5 fig, 2 append, 5 ref.
Descriptors: *Flow measurement, *Flumes, *Portability, *Water measurement, Flow
rates, Water conservation.
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A portable flume-site survey flume was constructed and used to verify siting of
permanent metering flumes. The portable system consists of a trapezoidal throat
that can be raised and lowered in a flowing field ditch to establish limits of
unsubmerged operation and backwater effects on upstream structures. Mechanical
solutions to problems of maintaining gage-zero on a movable throated flume,
stilling well readout, and movable seals between ditch and flume were presented.
A family of concrete throat sections, differing only in height of installation
from the flume floor, were recommended for the permanent installations. Flows
between about 0.5 cfs (0.01 m3/s) and 25 cfs (0.7 m3/s) can be measured with the
portable system. Satisfactory operation can be achieved with less than 4 inches
(10 cm) head loss to the canal system. Permanent structures can be installed
with high assurance that they will operate as intended, be convenient enough to
be routinely used and rugged enough to remain reliable and accurate.
75:04A-007
REDUCED IRRIGATION TAILWATER RUNOFF FOR INCREASED WATER-USE EFFICIENCY,
Schneider, A.D., New, L.L., Musick, J.T.
Agricultural Research Service, United States Department of Agriculture, Bushland,
Texas.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 18 p, 4 fig, 4 tab, 8 ref.
Descriptors: *Return flow, *Irrigation effects, *Irrigation practices, *Tail-
water, Water conservation, Irrigation water.
Duration of tailwater runoff from 570-m long graded furrows did not significantly
affect field average yields of grain sorghum grown on a slowly permeable soil.
Irrigation water-use efficiency varied inversely with the time of tailwater run-
off. Conclusions from this study were: 1. The field average grain sorghum yield
on 570-m long irrigated furrows of Pullman clay loam was not seriously affected by
tailwater runoff duration. Major yield reduction occurred only in the lower 180 m
of the field; 2. Limiting or reducing tailwater runoff increases the irrigation
water-use efficiency of grain sorghum grown on graded-furrow irrigated Pullman
clay loam. The results should be applicable to other drought-resistant crops on
similar soil; and, 3. A limited tailwater runoff irrigation procedure permits
irrigating larger acreages with a fixed water supply.
75:04A-008
ANNOTATED BIBLIOGRAPHY ON TRICKLE IRRIGATION,
Smith, S.W., Walker, W.R.
Colorado State University, Fort Collins, Colorado. Agricultural Engineering
Department, Environmental Resources Center.
Information Series No. 16, June 1975. 61 p.
(See 75:03F-039)
75:04A-009
AN IMPLICIT METHOD TO SOLVE SAINT VENANT EQUATIONS,
Greco, F., Panattoni, L.
IBM Scientific Center, Pisa (Italy).
Journal of Hydrology, Vol. 24, p 171-185, 1975. 5 fig, 2 tab, 31 equ, 9 ref.
Descriptors: *Mathematical studies, Mathematics, Hydrographs.
An implicit numerical method for solving Saint Venant equations has been defined
for an application relating to the river Arno. This method exploits the linearity
in the discharge of the mass equation, by means of which it is possible to express
the discharge as a function of the water level and to use this expression in the
equation of motion. Then the resulting non-linear equation for a grid element on
the (x,t) plane contains only the water levels as unknown quantities. The solu-
tion of the system of equations for the entire reach, by the use of the Newton
iteration method, is facilitated by the particular form of the matrix of the co-
efficients. The rapid rate of convergence and the limited storage allocation are
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characteristics of this implicit scheme. This method has been compared with other
implicit methods based on the same grid of points.
75:04A-010
SOUTH PLATTE RIVER FLOW CORRELATIONS,
Glover, R.E.
Colorado State University, Fort Collins, Colorado.
Department of Civil Engineering
Journal of the Irrigation and Drainage Division, Vol. 101, No. IR3, p 175-186,
September 1975. 2 fig, 3 tab, 3 equ, 15 ref, 1 append.
Descriptors: *River flow, *River system, Rivers, River forecasting, Colorado,
Water resources.
An effective administration of the water resources of the South Platte River
Valley will require a quantitative advance evaluation of the effects to be expected
from decisions to be made. To serve this need a method of computation is proposed.
In developing this method excellent precedents have been followed. One case will
be cited to illustrate the procedure. Isaac Newton had been developing mathematics
which would permit the computation of an orbit (4). He states: "... and in the
same year (1666). I began to think of gravity extending to the orb of the moon . .
. having thereby compared the force requisite to keep the moon in her orb with
the force of gravity at the surface of the earth and found them to answer pretty
nearly." Note that when he completed it he had an experimentally based law. In
the present case, where direct experiment is precluded because of serious practi-
cal difficulties it can still be possible to develop a technically sound expres-
sion for the flow of ground water and to establish its validity by testing it
against the historic performance of the river. If computed and observed flows are
in agreement the validity of the procedure is confirmed. This was the procedure
followed.
75:04A-011
WHAT'S IN THE FUTURE FOR SPRINKLER IRRIGATION?,
Splinter, W.E.
Nebraska University, Agricultural Engineering Dept.
Irrigation Age, Vol. 9, No. 6, 2 pages, March 1975.
Descriptors: Irrigation, Sprinkler irrigation, Irrigation practices, Irrigation
systems.
Man's recognition of the need for water for plants appears nearly as old as
agriculture. Ancient works in Asia Minor indicate that quite complex irrigation
systems were developed several thousand years ago. Many of the ancient systems
are still in use. The use of external energy to move water appeared first with
the use of wind powered pumping plants. Since its inception irrigation has
required high inputs of effort and management.
75:04A-012
COMPARING THREE MECHANICAL MOVE SPRINKLERS WITH GATED PIPE,
Irrigation Age, Vol. 9, No. 8, p 28-29, May-June 1975.
Descriptors: *Sprinkler irrigation, *Furrow irrigation, Irrigation, Irrigation
systems.
Paul Fischbach, University of Nebraska extension irrigationist, recently spelled
out the positive sides of mechanical move sprinklers vs. gated pipe during the
Sprinkler Irrigation Association's annual technical conference in Atlanta.
75:04A-013
CALIFORNIANS FIGHT SALT WITH WATER,
Irrigation Age, Vol. 9, No. 9, p 14-15, July-August 1975.
Descriptors: Irrigation, Furrow irrigation, Sprinkler irrigation, Soil-salinity,
Salinity, Soils.
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Confronted with two techniques for reducing salt levels while preparing soil in
the Imperial Valley, a Brawley, California farm manager has opted for a combina-
tion of both: row irrigation and sprinkler irrigation. But his emphasis is still
on sprinkling, which has become popular for germinating a crop.
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Section XVII
WATER QUANTITY MANAGEMENT AND CONTROL
GROUNDWATER MANAGEMENT (GROUP 04B)
75:043-001
A DISCRETE KERNEL GENERATOR FOR STREAM-AQUIFER STUDIES,
Morel-Seytoux, H.J., and Daly, C.J.
Colorado State University, Fort Collins. Department of Civil Engineering
Water Resources Research, Vol. 11, No. 2, p 253-260, April 1975. 5 fig, 3 tab,
22 ref, 2 append.
Descriptors: *Surface-groundwater relationships, *Mathematical models, *Cost
comparisons, *Aquifer management, "Computer models, "Conjunctive use, Econo-
mics, Water rights, Drawdown, Water wells, Porosity, Transmissivity, Regulation,
Allumial aquifers, Model studies, Finite element analysis.
A finite difference model of the behavior of an aquifer without stream inter-
action was developed as a first-state component of a management model of a
stream-aquifer system. The model was not built as a usual simulator but as a
discrete impulse response generator. Once the basic response coefficients
were generated, the finite difference model was no longer necessary to simulate
the behavior of the aquifer. Any aquifer response (e.g., return flow to a given
reach for a given week) was expressed as an explicit function of the pumping
rates. A complete description of the 'discrete kernel generator1 was provided
including the basic equations, truncation error propagation, accuracy, and run
costs.
75:04B-002
NEW EQUATIONS FOR DETERMINING THE FORMATION CONSTANTS OF AN AQUIFER FROM PUMPING
TEST DATA,
Boulton, N.S., and Streltsova, T.D.
Sheffield University (England). Department of Civil and Structural Engineering.
Water Resources Research, Vol. 11, Ho. 1, p 148-153, February 1975. 2 fig, 5 tab,
11 ref, 1 append.
Descriptors: *Groundwater, "Pumping, "Aquifer testing, Confined water, Aquicludes,
Permeability, Drawdown, Storage coefficient, Transmissivity, Hydraulics, Hydro-
logic properties, Equations, Sandstones.
New equations were given, based on an extended theory, that take into account
the following factors: the compressibility and anisotropy of the main aquifer;
the partial penetration of the abstraction well; the depth at which the draw-
down in an observation well is measured; the existence of a low-permeability
layer, called "the aquitard,' above the aquifer; and the saturated and unsatu-
rated zones above the water table. A practical method of evaluating the forma-
tion constants for an aquifer from pumping test data was fully discussed. Type
curves based on the new equations were used to analyze data from a pumping test
in the thick Bunter sandstone formation of Shropshire (Great Britain). A correc-
tion for the water derived from storage within the abstraction well was found
to be necessary.
75.-04B-003
ANALYSIS OF FLOW TO AN EXTENDED FULLY PENETRATING WELL,
Javandel, I., and Zaghi, N.
Pahlavi University, Shiraz (Iran).
Water Resources Research, Vol. 11, No. 1, p 159-164, February 1975. 10 fig, 10
ref.
Descriptors: "Groundwater, "Water wells, "Potential flow, Hydraulics, Ground-
water potential, Fourier analysis, Groundwater movement, Water yield, Safe
yield, Discharge(Water).
134
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An analytic solution was derived yielding the potential distribution in a bounded
confined aquifer pumped by a well that was radially extended at the bottom. An
exact solution for the rate of discharge was found by which the effect of local
radial extension on the increase of the pumping rate was studied. Solutions
were evaluated numerically, and the results were presented graphically in terms
of dimensionless parameters. The results showed that production rate is doubled
in some cases by extending the bottom of the well.
75:04B-004
WELL PUMPING IN UNCONFINED AQUIFERS: THE INFLUENCE OF THE UNSATURATED ZONE,
Krosynski, U.I., and Dagan, G.
Technion-Israel Institute of Technology, Haifa. Faculty of Civil Engineering.
Water Resources Research, Vol. 11, No. 3, p 479-490," June 1975. 7 fig, 1 tab,
18 ref.
Descriptors: *Groundwater, *Water table aquifers, *Unsaturated flow, *Unsteady
flow, *Mathematical studies, Capillary conductivity, Hydraulic conductivity,
Soil water movement, Aquifer characteristics, Aquifer testing, Numericak analysis,
Finite element analysis, Drawdown, Equations, Approximation method, Wells.
An approximate analytical solution describing transient flow toward a partially
penetrating well pumped at a constant discharge in a rigid, homogeneous, aniso-
tropic, unconfined aquifer of infinite radial extension and finite depth,
considering flow in the unsaturated zone above the free surface, was presented.
The characteristic hydraulic properties of the unsaturated zone, namely the
retention and hydraulic conductivity curves, were described by analytical expres-
sions that depended on a parameter which roughly represented the effective thick-
ness of the unsaturated zone. To check the validity of the approximate analytical
solution, the problem, free of such approximations, was solved numerically by
a finite element scheme for a representative particular case. Comparison between
analytical and numerical solutions, showed excellent agreement. The influence of
the unsaturated zone was found to be negligible for most common cases encountered.
In the marginal cases of very shallow rigid aquifers and of soils with particu-
larly large unsaturated effective thickness, the influence of the unsaturated
zone upon drawdown was found to be significant only at relatively short times,
close to the pumping well and close to the free surface.
75:048-005
SCREENING MODEL FOR CONJUNCTIVE-USE SYSTEMS,
Hamdan, A.S., Meredith, D.D.
Harza Engineering Company, Chicago, Illinois.
Journal of the Hydraulics Division Vol. 101 No. HY10 p 1343-1355. October 1975.
2 fig, 4 tab, 16 ref, 2 append.
(See 75:04A-004)
75:04B-006
ITERATIVE METHOD OF DETERMINING AQUIFER CONSTANTS,
Gill, M.A.
Ahmadu Bello University, Zaria, Nigeria. Department of Civil Engineering.
Journal of the Irrigation and Drainage Division Vol. 101, No. IR1, p 81-85
March 1975. 1 fig, 1 ref, 2 append.
Descriptors: *Aquifer characteristics, *Aquifers, *Aquifer testing, *Mathematical
studies, This equation.
In the proposed method, it is possible to consider as many terms in the series
of Eq.3 as may be significant for calculating the aquifer constants. Therefore,
the method can be considered as a refinement or extension of Jacob's method in
which only the first two terms of the series are considered. It can be compared
with the Theis method in which the "match" of the drawdown curve with the type
curve is obtained graphically. In the proposed method, the "match" is obtained
algebraically- The aquifer constants determined by the proposed method satisfy
135
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Eq. 3 for the two selected values of s and r2/t. Because the two points are
selected from a smooth curve passing through the test data, the fit generalJ.y
is good at all the other points also.
75:04B-007
PRIVATE CONSTRAINTS ON GROUNDWATER CONTAMINATION,
Walker, W.R., Cox, W.E.
Virginia Polytechnic Institute and State University, Blacksburg. Water Resources
Research Center. uvin
Journal of the Hydraulics Division Proceedings of ASCE, Vol. 101, No. HYJ.U,
p 1333-1341, October, 1975. 29 ref.
Descriptors: *Groundwater, *Water rights, *Water quality control, *Water pollu-
tion control, Hydrologic aspects, Legal aspects, Water pollution sources, Water
supply.
While water rights have been supplemented by direct governmental controls in
the case of surface waters, protection of groundwater quality has been inade-
quate. Various judicial decisions regarding the rights of a groundwater user to
an uncontaminated water supply are presented. The interpretations of court cases
showed no clear patterns of legal action. In many cases, potential sources of
groundwater pollution are essentially unregulated, and in cases where penalties
for groundwater contamination do exist, there is no means for assuring recovery
of losses. A 1970 survey indicated that groundwater constituted about one-third
of public water supplies and provided about 95% of water used by 41 million people
served by private domestic systems in the United States. It was strongly recom-
mended that more comprehensive and effective controls are needed to supplement
the mechanism of water rights and to protect the domestic water supplies.
75:04B-008
HAMMER SEISMIC TIMING AS A TOOL FOR ARTIFICIAL RECHARGE SITE LOCATION,
Bianchi, W.C., Nightingale, H.I.
Agricultural Research Service, Fresno, California. Water Management Research.
Soil Science Society of America Proceedings, Vol. 39, No. 4, p 747-751, July-
August 1975. 4 fig, 4 tab, 14 ref.
Descriptors: *Seismology, *On-site investigations, *Groundwater, *Artificial
recharge, *Water spreading, *California, Seismic properties, Seismic waves, Travel
time, Seismic studies, Alluvial aquifers. Aquifers, Geophysics, Exploration,
Equipment, Groundwater recharge, Recharge ponds, Sites.
Hand carried hammer impact seismic timing equipment utilizes the physics of
seismic wave refraction to explore stratigraphic changes deeper than those found
on soils maps. In alluvial areas, artificial recharge and liquid waste disposal
sites were selected from sandy, single-grained soil series noted for their high
water-transmitting properties through the surface 2m. The surface horizon seismic
velocity exhibited by these soils in the San Joaquin Valley had a very narrow
range (V sub 1 = 315-440 m/sec), which gave good definition to the refraction off
the second horizon (V sub 2 = 610-2,100 m/sec). Accurate information on depth
and horizontal continuity of this second horizon could be obtained in areal surveys.
A third horizon may often be described, but its areal continuity is usually masked
by intermediate discontinuous layers above it of equal or lesser refractivity.
All groundwater recharge by water spreading.
75:04B-009
DRAWDOWN SOLUTIONS FOR SIMULTANEOUS DRAINAGE AND ET,
Skaggs, R.W.
North Carolina State University, Raleigh. Department of Biological and Agricul-
tural Engineering.
Journal of the Irrigation and Drainage Division, American Society of Civil
Engineers, Vol. 101, No. IR4, Proceedings Paper 11804, p 279-291, December 1975.
9 fig, 16 ref, 2 append.
Descriptors: *Drainage, *Seepage, *Drains, *Evapotranspiration, *Water table,
136
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Subsurface drainage, Ditches, Drawdown, Subsurface drains, Tiles, Drainage effects,
Numerical analysis, Graphical methods, Deep percolation, Dupuit-Forchheimer theory,
Groundwater movement, Soil water movement, Hydraulic conductivity.
Numerical methods were used to solve the nonlinear Boussinesq equation for water
table drawdown between parallel drains. The solutions were compared to other
methods of predicting drawdown for initially horizontal, parabolic, and elliptical
profiles, and good agreement was found with methods that considered the nonlinear
aspects of the governing equation. Solutions were presented in graphical form
for simultaneous drainage and ET or deep seepage. Example problems were solved
to show the use of these solutions for evaluating the effect of ET or deep seepage
on water table drawdown and for considering this effect when predicting drain
spacings to satisfy a predetermined drawdown rate. The solutions were also used
in an example to explain apparent discrepancies in field tests of drain spacing
equations.
75:04B-010
GROUND-WATER RECHARGE RATES FROM THERMOMETRY,
Nightingale, H.I.
Agricultural Research Service, Fresno, California.
Ground Water, Vol. 13, No. 4, p 340-344, July-August 1975. 5 fig, 4 tab, 12 ref.
Descriptors: *Groundwater, *Recharge, *Temperature, *Recharge ponds, *Water
temperature, *California, Air temperature, Percolating water, Fourier analysis,
Percolation, Seepage, Infiltration, Groundwater movement, *Artificial recharge,
Statistics.
Basin artificial groundwater recharge rate at the Leaky Acres Recharge Project in
Fresno, California, was evaluated by Fourier analysis of temperature variations
of air, basin water, and groundwater. The weekly mean basin water temperature
correlated well (r=0.982) with weekly mean air temperature. Weekly mean tempera-
ture data of the air, basin water, and recharged groundwater showed that the first
harmonic curve was satisfactory for determining the times of minimum and maximum
temperature when convective transfer of heat was considered. The lag time between
maximum basin water temperature and maximum groundwater temperature at a 16 m
depth, showed water moved at a thermal tracer velocity of 20.8 cm/day. The corres-
ponding infiltration rate measured by the falling-head method in study area basins
was 18.5 cm/day- This indicated that under suitable conditions with simple field
instrumentation groundwater thermometry can be used to estimate the rate and
direction of recharged water movement.
75:04B-011
UPCONING OF THE SALT-WATER-FRESHWATER INTERFACE BENEATH A PUMPING WELL,
Chandler, R.L., McWhorter, D.B.
Colorado State University, Fort Collins. Department of Agricultural Engineering.
Ground Water, Vol. 13, No. 4, p 354-359, July-August 1975. 6 fig, 1 tab, 9 ref.
Descriptors: *Saline water-freshwater interfaces, *Water wells, *Penetration,
Pumping, Saline water, Water table, Anisotropy, Isotropy, Optimization, Permeabil-
ity, Entrainment, Dupuit-Forchheimer theory, Mathematical models, Model studies,
Numerical analysis. Boundaries(Surfaces), Equations, Density, Pressure head,
Discharge(Water).
The upconing of saline water in response to pumping from an overlying layer of
fresh water was investigated by numerical integration of the governing differential
equation. The transition zone between the fresh and saline water was idealized
as an abrupt interface. Full consideration of the nonlinear boundary conditions
on the water table and interfacesurface was included for steady flow toward partial-
ly penetrating pumping wells in both isotropic and anisotropic aquifers. There
exists an optimum well penetration into the fresh-water layer which permits maxi-
mum discharge without salt-water entrainment. The optimum penetration increases
as the vertical permeability is reduced relative to the horizontal permeability.
The maximum well discharge obtainable without salt-water entrainment is greater
137
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for aquifers with a reduced vertical permeability than for isotropic aquifers, a
result that contrasts with previously published conclusions. Previous analyses
which linearize the boundary condition on the interface overestimated the criticaj.
discharge.
75:04B-012
CONJUNCTIVE AVAILABILITY OF SURFACE AND GROUND WATER IN THE ALBUQUERQUE AREA,
NEW MEXICO: A MODELLING APPROACH,
Brutsaert, W.F., Gebhard, T.G.Jr.
Maine University, Orono. Department of Civil Engineering.
Ground Water, Vol. 13, No. 4, p 345-353, July-August 1975. 9 fig, 4 tab, 6 ref.
Descriptors: *Surface-groundwater relationships, Conjunctive use, *Model studies,
*Simulation analysis, *Available water, *New Mexico, Water management(Applied),
Aquifer systems, Computer models, Forecasting, Regression analysis, Groundwater,
Water resources development, Groundwater basins, Groundwater potential.
The relationship of dynamic ground-water availability and aquifer behavior under
projected stresses was modeled by a groundwater system simulator based on a mass
balance of the hydrologic basin. Conditions from extreme dry to extreme wet
were modeled, combined with a range of different water demands. A vast amount of
information was thus obtained in the form of aquifer responses for different con-
ditions. An analogous relationship was constructed from these data by stepwise
multiple regression analysis of the change in water-table elevation at the end of
the previous time period, and lump factor combining surface-water inflow and out-
flow, precipitation, and beneficial and nonbeneficial water uses. Other results
readily obtainable from the simulation runs were river accretion or depletion
curves as a function of time. These curves showed the diversion effects of ground-
water pumping upon the river.
75:048-013
A MULTIPLE-WELL, WATER-LEVEL MEASURING AND RECORDING SYSTEM,
Holbo, H.R., Harr, R.D., Hyde, J.D.
Oregon State University, Corvallis. Forest Research Lab.
Journal of Hydrology, Vol. 27, No. 3/4, p 199-206, December 1975. 4 fig, 3 ref.
Descriptors: *Instrumentation, *Water level recorders, *Remote sensing, Automatic
control, Electronic equipment, Water level fluctuations, Piezometers, Electrodes,
Observation wells, Measurement, Data collections.
An electronic measuring and receding system was designed to make periodic measure-
ments of water level simultaneously in sixteen small-diameter piezometers. The
system can operate unattended from battery power in remote areas for 2-4 weeks.
Output data are easily read and are readily adaptable to computer entry for analy-
sis and plotting.
75:04B-014
PHYSICAL FUNDAMENTALS OF THE MIXING OF SOLUTIONS OF POLLUTANTS AND SEWAGE IN
POROUS MEDIA,
Klotz, D.
Institut fur Radiohydrometric der Gesellschaft fur Strahlen- und Umweltforschung
mbH. 8042 Neuherberg (Munchen). Ingolstadter Laudstrabe 1, Federal Republic
of Germany.
Water Research Vol. 9, No. 12, p 783-790, December 1975. 15 fig, 1 tab, 12 equ,
18 ref.
Descriptors: *Water quality, *Groundwater, Pollution, Porous media, Sewage,
Diffusion, Aquifer characteristics.
The increasing danger of ground-water pollution by pollutants from the environment
and by increasing amounts of sewage requires an exact examination of the mechanisms
of distribution and transport within the water-bearing stratum. Two mixing pro-
cesses occur substantially in case of the simultaneous propagation of two miscible
138
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liquids in a porous medium (water-bearing stratum): hydrodynamic dispersion and
molecular diffusion. If a region of flow is marked in a liquid (ground-water)
flowing through a porous medium with a further liquid (solution of pollutants,
sewage) being miscible therewith, this marked region increases as regards its
extension during the joint movement of the two liquids. A mixing of the "marking
substance" with the flowing liquid occurs, the decrease in concentration of the
"marking substance" being a measure for the degree of intermixture.
75:04B-015
DETERMINING OPTIMAL WELL DISCHARGE,
Helweg, O.J.
Colorado State University, Fort Collins.
Journal of the Irrigation and Drainage Division, Proceedings of the American
Society of Civil Engineers, Vol. 101, No. IR3, Proceedings paper No. 11566, p
201-208, September 1975. 5 fig, 6 ref, 3 append.
Descriptors: *Wells, *Discharge(Water), *Pumping, *Groundwater, *Irrigation,
*Geohydrologic units, Optimization, Methodology, Cost-benefit analysis, Water supply,
Drainage, Design, Cost-benefit ratio, Computers, Equations, Drawdown, Project
planning, Systems analysis, Evaluation.
The cost of pumping groundwater is a major factor in water supply; it is necessary
to pump a given well at the discharge that maximizes the net benefit of the opera-
tion. Previous criteria have ignored the economic aspects of the analysis of this
problem. This paper presents a method for determining the optimum operating
policy of a well, i.e., at which discharge a well owner receives the most water
for his money. A computer code, QOPTIM, is included along with an example of the
analysis. The case treated is pumping an existing well at the optimum discharge,
where drilling the well is a sunk cost. The real world example shows the importance
of considering well losses in any analysis. An appendix lists QOPTIM, which can
be easily used by most engineering offices to find the optimal discharge of a
given well. The choice of criterion for finding the optimal well discharge is
important. Application results of the cost-benefit, optimization method developed
herein show power costs for a well to be $2,350/yr greater if the well is pumped
at two thirds drawdown rather than at the optimal discharge as found using QOPTIM.
139
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Section XVIII
WATER QUANTITY MANAGEMENT AND CONTROL
EFFECTS ON WATER OF MAN'S NONWATER ACTIVITIES (GROUP 04C)
75:04C-001
ENERGY, AGRICULTURE AND WASTE MANAGEMENT,
Jewell, W.J. (Editor)
Cornell University, Department of Agricultural Engineering. Ithaca, New York.
Ann Arbor Science Publishers, Inc. P.O. Box 1425, Ann Arbor, Michigan 48106.
1975. 540 p.
Descriptors: *Energy, *Agriculture, *Waste treatment, *Waste disposal, Food
abundance, Feed lots, Engineering.
Agriculture requires significant energy resources for food and fiber production.
New energy demands have also been created in controlling wastes to improve envi-
ronmental quality. Recently, these two areas have been linked by studies that
emphasize the possibility of converting wastes to energy sources. This book
discusses in detail three main topics: 1) Energy consumed in food production 2)
Technology and energy costs of pollution control, and 3) Potential for producing
energy from agricultural wastes. An outstanding feature is the large amount of
information compiled on anaerobic fermentation, and the discussion of this tech-
nology in producing energy from wastes. To date, few answers have emerged for the
engineers, scientists, and policy makers who must recommend directions for the
future of food production, energy use and environmental pollution control—these
chapters present one of the first attempts to answer these questions. This volume
will be a valuable reference for civil, agricultural, and environmental engineers,
water pollution control officials, microbiologists, wildlife biologists, and pro-
fessors of environmental engineering.
140
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Section XIX
WATER QUANTITY MANAGEMENT AND CONTROL
WATERSHED PROTECTION (GROUP 04D)
75:040-001
SOIL MOISTURE ACCOUNTING COMPONENT OF THE USDAHL-74 MODEL OF WATERSHED HYDROLOGY,
England, C.B.
Agriiultural Research Service, Northeastern Region, United States Department of
Agriculture, Beltsville, Maryland 20705
Water Resources Bulletin, Vol. 11, No. 3, p 559-567, June 1975. 3 fig, 1 tab,
7 ref.
Descriptors: *Soil moisture, *Model studies, Watersheds(Basins), *Hydrology,
Watershed management, Oklahoma.
Soil moisture in two layers of soil near Chickasha, Oklahoma, was simulated, using
USDAHL-74 Model of Watershed Hydrology. Weekly values computed for both layers
compared well with those observed during the 15-month period. Certain key
parameters required adjustments in the model which illustrate the need for accu-
rate input information. The experiment demonstrates that the model, which has
previously given good results in continuous streainflow prediction on watersheds
up to 100 square miles, can also compute soil moisture continuously at a site.
This capability suggests other model uses, for example, in monitoring the dispo-
sition of applied chemicals.
141
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Section XX
WATER QUALITY MANAGEMENT AND PROTECTION
IDENTIFICATION OF POLLUTANTS (GROUP 05A)
75:05A-001
URBAN SEDIMENT PROBLEMS: A STATEMENT ON SCOPE, RESEARCH, LEGISLATION, AND
EDUCATION,
The Task Committee on Urban Sedimentation Problems of the Committee on Sedimenta-
tion of the Hydraulics Division,
American Society of Civil Engineers.
Journal of the Hydraulics Division, Vol. 101, No. HY4, p 329-340, April 1975.
1 tab, 7 ref.
Descriptors: *Sediments, *Sedimentation, Sediment control, Urban runoff,
Urbanization.
Erosion and sediment pollution problems are serious in many urban and urbanizing
areas because such areas and their waters are important to society; therefore,
urban sediment problems need attention. This report hopefully will stimulate
progress toward awareness of urban sediment problems.
75C5A-002
PHOSPHATE DETERMINATIONS IN WATERS USING AN ANION EXCHANGE RESIN,
Blanchar, R.W., Riego, D.
Missouri Agricultural Experimental Station, Missouri University, Columbia.
Journal of Environmental Quality, Vol. 4, No. 1, p 45-49, January-March 1975.
5 fig, 4 tab, 10 ref.
Descriptors: *Phosphates, *Water quality, Water quality control.
Amounts of water samples from 1 to 1000 ml were passed through 10-cc columns of
100- to. 200-mesh Dowex 1-X8 anion-exchange resin. Orthophosphate was quantita-
tively removed from the water sample by the resin and could be eluted from the
column with 25 ml of 1M KC1. Phosphate in the 1M KCl eluent was reacted with
ammonium molybdate, extracted into isobutanol, reduced with SnCl(2), and the
optical density of the blue complex measured. The working range of the method
was between 1 and 8 raicrograms of P. Analysis of water samples indicated that
in the 1 to 20 ppb P range an appreciable amount of the phosphate exists as pyro-
and tripoly-phosphate. The resin method is not specific for dissolved ortho-
phosphate in water, but may give a more valid estimate than direct reaction with
the acid molybdate reagent.
75:05A-003
SOME OBSERVATIONS CONCERNING PREPARATION AND STORAGE OF STREAM SAMPLES FOR DIS-
SOLVED INORGANIC PHOSPHATE ANALYSIS,
Johnson, A.H., Bouldin, D.R., and Hergert, G.W.
Cornell University, Ithaca, N.Y. Dept. of Agronomy.
Water Resources Research, Vol 11, No 4, p 559-562, August, 1975. 3 fig, 9 ref,
4 tab.
Descriptors: *Water analysis, *Phosphates, *Storage, Time, Inorganic compounds,
Analytical techniques, Water pollution sources, Trace elements, Water pollution,
Phosphorus compounds, Water properties, Freezing, Refrigeration, Pollution
identification, New York.
The influence of storage conditons and duration of storage was studied by using
about 100 stream samples from Fall Creek collected near Ithaca, New York. Freez-
ing and refrigerated storage were unsatisfactory, since changes in measured
concentrations were usually observed after relatively short periods of time (24
hr). An isobutanol extraction procedure is described which minimizes storage
problems and is useful for routine analysis of water samples for dissolved
inorganic phosphate.
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75:05A-004
NITRATE MEASUREMENTS USING A SPECIFIC ION ELECTRODE IN PRESENCE OF NITRITE,
Francis, C.W., and Malone, C.D.
Oak Ridge National Lab., Tennessee.
Soil Science Society of America Proceedings, Vol. 39, No. 1, p 150-151, January-
February 1975. 2 fig, 1 tab, 9 ref.
Descriptors: *Nitrates, *Nitrogen compounds, *Analytical techniques, *Instru-
mentation, *Measurement, Inorganic compounds, Chemicals, Denitrification,
Nitrites, Water quality, Colorimetry, Analysis, Estimating, Evaluation, Ions,
Electrodes, *Pollutant identification.
The presence of the nitrite anion N02(-) may lead to a significant error in mea-
suring NO3-N concentrations with a specific ion electrode. Interference by nitrite
was eliminated by complexing the nitrite with sulfanilamide in 0.01 N H2SO4. In
this manner, nitrate levels can be read directly in concentrations ranging from
10 to 5000 ppm NO3-N. The method is particularly useful in denitrification
studies where HC03(-) and COS(—) anions as well as NO2(-) preclude direct NO3-N
measurements.
75:05A-005
THE TIME STABILITY OF DISSOLVED MERCURY IN WATER SAMPLES-I. LITERATURE REVIEW,
Jenne, E.A., Avotins, P.
United States Department of the Interior.
Journal of Environmental Quality, Vol. 4 No. 4 p 427-431. October-December 1975.
49 ref.
Descriptors: *Mercury, *Water quality, *Sampling, Bacteria, Preservation.
Conflicts in the published findings of adequacy of various preservation treatments
for water samples intended for mercury analysis are common and appear to result
from variations in (i) biological effects; (ii) initial concentrations of mer-
cury; (iii) types of containers used; (iv) properties of the water or laboratory
solution (particularly, the dissolved organic and reduced metal cation content);
(v) duration of experiment; (vi) concentration of preservative; (vii) analysis,
whether conducted in the original adequacy employed. Of these variables the
biological effects have been overlooked by most investigators.
75:05A-006
MONITORING AGRICULTURAL POLLUTION USING NATURAL FLUORESCENCE,
Lakshman, G.
Saskatchewan Research Council, Saskatoon.
Water Resources Research, Vol. 11, No. 5, p 705-708, October 1975, 9 fig, 1 tab,
7 ref.
Descriptors: *Monitoring, *Fluorescence, Analytical techniques, *Agricultural
runoff, *Farm wastes, *Water pollution, Data collections, Measurement, Data trans-
mission, Indicators, Pollutants, Water quality, *Pollutant identification, Fluoro-
metry, Surface runoff. Organic compounds, Organic wastes, Nutrients, Sampling,
Feed lots.
Many organic and bio-organic compounds exhibit natural fluorescence in the visible
spectrum. In many cases this is strong enough to be used as a technique to moni-
tor the presence of pollutants from animal wastes on land and in water. A number
of soil and runoff samples from feedlot wastes have been analyzed for the nature
and stability of their natural fluorescence. A strong correlation exists between
the fluorescence emission and the water quality parameters such as total carbon
(TC), total organic carbon (TOO, and total inorganic carbon (TIC). It can be
used in the quantitative measurement of agricultural pollution, and future re-
search should help to exploit the technique for remote sensing applications.
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75:05A-007
VALIDITY OF SOIL-WATER SAMPLES COLLECTED WITH POROUS CERAMIC CUPS,
Hansen, E.A., Harris, A.R. . t-inn
Forest Service (USDA) Cadillac, Michigan. North Central Forest Experiment Station.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 528-536, May June
1975. 9 fig, 2 tab, 8 ref.
Descriptors: *Equipment, *Sampling, *Soil water, Pollutants, Nutrients, Phosphor-
us, Nitrates, Laboratory tests, On-site investigations, Water pollution, Soil
contamination, Soil filters, *Pollutant identification, Water quality.
Laboratory and field tests were made to determine if porous ceramic cups collect
representative samples of nitrate and phosphate from soil water. Substantial bias
and variability were found. Some of the sources of sample bias were soroption,
leaching, diffusion, and screening of phosphate ions by the cup walls. Sample
variability of nitrate ions was strongly influenced by sampler intake rate,
plugging, sampler depth, and type of vacuum system (which simulated different sam-
pler sizes). These factors affect timing of sample collection and, because nutri-
ent concentration in soil water is continually changing, they in turn affect sample
concentration. These factors produced as much .as a 60% range in sample concentra-
tion from 8 samplers installed in a small uniform plot. Added to this variability
is an unknown amount of bias representing the difference between the sample
concentration and the average drainable soil-water concentration. The many factors
affecting the sample concentration together with the demonstrated variability and
unknown bias make interpretation of sampler data difficult. To reduce sample
variability, samplers should be grouped by intake rate. Short sampling intervals,
uniform sampler lengths, and the same initial vacuum should be used for all
samplers.
75:05A-008
METHODS AND DATA REQUIREMENTS FOR RIVER-QUALITY ASSESSMENT,
Rickert, D.A., Hines, W.G., McKenzie, S.W.
Geological Survey, Portland, Oregon.
Water Resources Bulletin, Vol. 11, No. 5, p 1013-1039, October 1975. 5 fig, 1 tab,
32 ref.
Descriptors: *Water resources, *Planning, *Management, *River basins, *Water
quality, Dissolved oxygen, Communication, Simulation analysis, Mathematical
models, Mapping, Systems analysis, Decision making, ^Oregon, Environmental effects.
The U.S. Geological Survey is conducting an intensive river-quality assessment of
the Willamette River basin, Oregon. The objectives are to (1) define a practical
framework for conducting comprehensive river-quality assessments, (2) develop and
document methods for evaluating basin-development alternatives in terms of poten-
tial impacts on river quality, (3) determine the kinds and amounts of data required
to adequately assess various types of river quality problems, and (4) apply the
framework, data, and methods to assess the existing or potential river-quality
problems of the Wilamette River basin. Considered herein are objectives 2, 3,
and 4, by examining the rationales behind the selection and application of methods
and the design of data programs for assessing specific river-quality problems.
The rationales are those developed for assessing (1) the effect of population
and industrial growth and resulting waste discharges on river-dissolved oxygen,
(2) the potentially harmful effects on land and river quality of accelerated ero-
sion resulting from intensive land-use development, and (3) the potential for
nuisance algal growth. The goal of the assessment program and, thus, the context
of the rationales is to provide technically sound information that is appropriate
and adequate for resource planning and management.
75:05A-009
SEDIMENT ROUTING FOR AGRICULTURAL WATERSHEDS,
Williams, J.R.
Agricultural Research Service, Temple, Texas.
Water Resources Bulletin, Vol. 11, No. 5, p 965-974, October 1975, 6 tab, 16 ref.
144
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Descriptors: *Sediment yield, *Agricultural watersheds, *Soil erosion, *Settling
velocity, *Texas, Sheet erosion, Rill erosion, Gully erosion.
A sediment routing technique was developed to route sediment yield from small
agricultural watersheds (less than or equal to 10 sq mi) through streams and
valleys to the outlet of large watersheds (less than or equal to 1000 sq mi) .
The procedure was based on the modified universal soil loss equation and a first
order decay function of travel time and particle size. Deposition was dependent
upon settling velocities of the sediment particles, travel time, and the amount
of sediment in suspension. Sediment routing increases sediment yield prediction
accuracy and allows determination of subwatershed contributions to the total
sediment yield. Also the locations and amounts of floodplain scour and deposition
can be predicted. Another advantage of sediment routing is that measured sediment
yield data are not required. The procedure performed satisfactorily in test
routings on two Texas blackland watersheds. More tests were planned with data
from other physiographic areas.
75:05A-010
SAMPLERS FOR MONITORING RUNOFF WATERS,
Manges, H.L., Nixon, C.C.
Kansas State University, Manhattan, Kansas.
Presented at the 1975 Winter Meeting of the American Society of the Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 10 p, 4 fig, 9 ref.
Descriptors: *Runoff, *Sampling, *Water sampling, Water analysis, Water pollution
effects, WAter pollution control.
A sampler is badly needed for collecting a proportional sample of runoff water
for laboratory analysis. Pollutant load in runoff would be calculated from sample
volume and pollutant concentration measurements. A sampler was designed and built
which divided flow with short tubes. In laboratory tests, sampling ratio became
constant after decreasing with increasing flow rates for unsubmerged flow and was
constant for submerged flow. Sampling ratio was quite variable during field test-
ing because of debris clogging the reservoir below the short tubes. A sampler
using orifices surrounded by short tubes in place of the short tubes alone for
dividing flow had a slightly better sampling ratio for unsubmerged flow and a
constant sampling ratio for submerged flow.
75:05A-011
BACTERIAL FLORA OF SALINE AQUIFERS,
Willis, C.J., Elkan, G.H., Horvath, E., Dail, K.R.
North Carolina State University, Raleigh. Department of Microbiology.
Ground Water, Vol. 13, No. 5, p 406-409, September-October 1975. 1 tab, 10 ref.
Descriptors: *Bacteria, *Methane bacteria, *Analytical techniques, *Aquifers,.
*Microorganisms, *Saline water, Chromatography, Sulfur bacteria, Anaerobic bacter-
ia, Aerobic bacteria, Pollutant identification. Chemistry, Instrumentation, Methane,
Analysis, On-site investigations, Florida, Surface waters. North Carolina, Soils,
Pollutants, Observation wells, Sampling, Water pollution, Industrial wastes,
Artesian aquifers, Injection wells, Waste disposal, Liquid wastes.
The bacterial flora of three unpolluted saline aquifers were examined. Aerobic,
anaerobic, and facultative microorganisms were isolated and classified to genus.
The organisms isolated were those commonly found in surface water and soil. Meth-
anogenic bacteria were present in all aquifers.
75:05A-012
A SEMIAUTOMATED PROCEDURE FOR THE DETERMINATION OF PHOSPHORUS IN WATER, WASTE
WATERS AND PARTICULATES,
Canelli, E., Mitchell, D.G.
New York State Department of Health, Albany.
Water Research, Vol. 9, No. 12, p 1093-1098, December, 1975. 3 fig, 10 ref, 4 tab.
145
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Descriptors: *Phosphorus compounds, *Water analysis, Analytical techniques, Water,
Waste water(Pollution), Dissolved solids, Phosphorus, Phosphates, Silicates, ™«
chemistry, Water properties, Colorimetry, Chemical analysis, *Pollutant laenriri
cation. Water pollution sources.
Improved procedures for the determination of total dissolved phosphorus (TOP),
particulate phosphorus (PP), and dissolved inorganic orthophosphate (DP) are
described. Organic particulate material is solubilized in 5 normal NaOH, and pnos-
phorus compounds are oxidized and mineralized to orthophosphate by persultate 01-
gestion. DP is determined by an improved automated molybdenum blue procedure that
does not require sample pH adjustment or a correction for silicate interference in
the 0-50 mg Si/liter range. The use of 36-position digestion racks allows 32 TDP
or PP samples to be digested in about 1 and 4 hr, respectively. Detection limits
in micrograms of phosphorus/liter are DP, 2; TDP, 5; and PP, 1. Waste water sam-
ples were analyzed for TDP and PP by the nitric acid-sulfuric acid procedure and
by the proposed method. There was no significant difference between the two sets
of data.
75.-05A-013
BACTERIOLOGICAL CRITERIA FOR GROUND-WATER QUALITY,
Allen, M.J., Geldreich, E.E.
Microbiological Quality Control, Water Supply Research Laboratory, U.S. Environ-
mental Protection Agency, National Environmental Research Center, Cincinnati, Ohio
45268.
Ground Water, Vol. 13, No. 1, p 45-51, January-February 1975. 1 fig, 8 tab, 22 ref.
Descriptors: *Groundwater, Groundwater resources, Water quality, Water quality
control, Water pollution, Pollution, Potable water.
Although more than 60 million individuals rely upon the absence of microbial path-
ogens in their marginally-treated or untreated ground-water supplies, an analysis
of reported waterborne disease outbreaks for the period 1946-1970 shows that
contaminated ground-water supplies were responsible for over 50 percent of the
outbreaks. Completed ground-water studies indicate: (1) coliforms and fecal
coliforms are present in a significant percentage of improperly located or inade-
quately protected private supplies, and (2) the apparent absence of coliforms due
to the insensitivity of currently available bacteriological methods does not pre-
clude pathogen occurrences. Excessive bacterial populations, normally not encoun-
tered in finished water, can suppress coliform detection. For this reason, it is
essential that improved bacterial detection methods be developed and other criteria
for untreated ground water be explored by comprehensive field investigations and
laboratory analysis of ground-water supplies for a variety of bacterial parameters.
75:05A-014
VARIATIONS IN THE NATURAL CHEMICAL CONCENTRATION OF RIVER WATER DURING FLOOD
FLOWS, AND THE LAG EFFECT: SOME FURTHER COMMENTS,
Walling, D.E., Foster, I.D.L.
Exeter Univ. CEngland). Dept. of Geography.
Journal of Hydrology, Vol 26, No. 3/4, p 237-244, August 1975. 3 fig, 2 tab, 7 ref.
Descriptors: *Chemical properties, *Correlation analysis, *Flood flow, Flood
routing, Flood peak, Flow characteristics, Hydrographs, Soil moisture, Pollutant
identification, Streamflow, Stbrm runoff, Hydrology, Specific conductivity. Time
Tag, Water chemistry, Calcium, Magnesium, Sodium, Potassium.
Results from several Devon catchments were used to demonstrate the complexity of
variations in the chemical concentration of river water during flood flows. Cer-
tain solute species increased rather than decreased in concentration during storm
events and the "chemographs1 of those species which exhibited dilution were often
complicated by a 'flushing effect.' Some solutes exhibited variable response,
evidencing increased and decreased concentrations during different events. Even
in small catchments, 'chemograph' response can lag behind streamflow response and
examples have been documented where the trough precedes the streamflow peak. Values
146
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of 'chemograph1 lag between zero and 14.5 hours were found at a gauging station on
the Devon River. This variation in lag time was tentatively explained in terms
of catchment moisture status. A multivariate relationship was developed between
'chemograph1 lag and four hydrologic variables: hydrograph rise, preceding flow
level, soil moisture deficit, and a seasonal index.
75:05A-015
DETERMINATION OF TOTAL MERCURY IN SOILS AND SEDIMENTS,
Floyd, M., Sommers, L.E.
Purdue University, West Lafayette, Indiana. Agricultural Experiment Station
and Department o'f Interior, Office of Water Research and Technology.
Journal of Environmental Quality, Vol. 4, No. 3, 1975. p 323-325, 3 tab, 9 ref.
Descriptors: *Mercury, Soils, Sediments, Pollution, Soil tests, Soil chemistry.
A simple one-step digestion procedure was evaluated for extracting total mercury
from soils and sediments. The procedure evaluated involves digesting soil or
sediment samples with concentrated HNO3 and 4N K2Cr207 (2:k,vol/vol) for 4 hours
at 55C and analyzing mercury in the extract by flameless atomic absorption.
Recovery of total mercury from diverse samples was comparable to or exceeded that
obtained by four alternative total mercury procedures. Essentially quantitative
recovery of mercury was obtained when samples were amended with mercuric chloride,
methylmercuric chloride, phenylmercuric acetate, and mercuric sulfide. The
procedure developed was precise with coefficients of variation ranging from 1 to
3%. Parameters affecting the quantitative extraction of total mercury were studied.
75:05A-016
GROUND-WATER POLLUTION PROBLEMS IN THE NORTHWESTERN UNITED STATES,
van der Leeden, F., Cerrillo, L.A., Miller, D.W.
Geraghty & Miller, Inc. Port Washington, New York 11050-
Publications No. EPA-660/3-75-018, 361 p, 60 fig, 48 tab, 459 ref, 3 append.
Descriptors: *Groundwater, *Groundwater resources, *Pollution, *Water quality,
Water quality control, Colorado, Idaho, Montana, Oregon, Washington, Wyoming,
Return flow, Water pollution.
An evaluation of ground-water pollution problems has been carried out in six
states in the northwest: Colorado, Idaho, Montana, Oregon, Washington and Wyo-
ming. The findings of the investigation indicate that, with the exception of
radioactive waste disposal, few cases of grounds-water pollution have been investi-
gated in detail. There is a need for baseline water-equality data and systematic
evaluation of overall ground-water conditions, expecially in urban zones, in areas
of petroleum exploration and development, and at locations of mining and industrial
activity. The most common natural ground-water quality problems, other than high
salinity, are excessive hardness, iron, manganese, and fluoride. Principal sources
of man-caused ground-water quality problems in the approximate order of severity
are: discharge of effluent from septic tanks and sewage treatment plants, irriga-
tion return flow, dryland farming, abandoned oil wells, shallow disposal wells,
unlined surface impoundments, mine tailings and mine drainage, municipal and in-
dustrial landfills, and radioactive waste disposal. Other sources that appear
to be of less importance but still must be considered include: spills and leaks,
application of fertilizers and pesticides, feedlots, and salt-water intrusion.
The findings of the investigation indicate that, with the exception of radioactive
waste disposal, few cases of groundwater pollution have been investigated in
detail.
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Section XXI
WATER QUALITY MANAGEMENT AND PROTECTION
SOURCES AND FATE OF POLLUTION (GROUP 05B)
75:05B-001
WATER QUALITY MODELING BY MONTE CARLO SIMULATION,
Brutsaert, W.F.
Maine University, Orono. Department of Civil Engineering.
Water Resources Bulletin, Vol. 11, No. 2, p 229-236, April 1975. 6 fig, 1 tab,
10 equ, 4 ref.
Descriptors: *Water quality control, *Simulation analysis, *Monte Carlo method,
*Stochastic processes, *Probability, Streams, Equations, Biochemical oxygen de-
mand, Dissolved oxygen, Mathematical models, Systems analysis, Optimum develop-
ment plans, Design, Wastes.
The applicability of Monte Carlo simulation to water quality modeling is
demonstrated using a simple Streeter-Phelps model. The model accounts for the
stochasticity of the input parameters. Triangular probability density function
are shown to be useful in case insufficient information is available to
define meaningful frequency distributions of input parameters. The model output
is presented as probability distributions of stream quality parameters. To
demonstrate the usefulness of the technique, a simple, critical DO-deficit prob-
lem is set up. The technique is applicable to optimizing design and operation
of wstewater treatment systems.
75:058-002
STOCHASTIC WATER QUALITY CONTROL BY SIMULATION,
Shin, C.S.
Texas University, San Antonio. Divison of Environmental Studies.
Water Resources Bulletin, Vol. 11, No. 2, p 256-266, April 1975. 5 fig, 6 tab,
6 equ, 11 ref.
Descriptors: *Water quality control, *Stochastic-processes, *Simulation analysis,
*Reliability, *River basins, *Management, Probability, Computers, Optimization,
Water policy, Standards, Regional analysis, Return flow, Effluents, Treatment
facilities, Streams, Decision making, Biochemical oxygen demand, Dissolved
oxygen, Costs, Systems analysis, Equations, Mathematical models, *Texas.
In order to handle the probabilistic nature of treated waste effluent character-
istics, the reliability associated with a basin-wide quality management goal
has been included in the modeling process. Meanwhile, the quantitative and
qualitative variations of the irrigation return flows and the urban runoff also
exhibit a probabilistic nature in terms of both temporal and spatial measurements.
Computer simulation had been utilized in analyzing the reliability and sensitivity
of a river basin quality management. A simulation-optimization scheme for the
determination of policies in regional water quality management has been developed
subject to specific water quality standards. Stochastic quadratic programming
techniques were used in the optimization analysis, the objective function con-
sisting of minimizing a convex quadratic cost function including the operating
cost, the amortization of capital expenditures and maintenance costs. A series
of simulation models describing the statistical water quality control phenomena
was developed. Meanwhile, a simulation analysis for the description of the
probabilistic nature of the stream quality was developed for the control strate-
gies of the return flows in the regional management system. As an illustration
of the applicability of this water quality control approach, the major waste-
water treatment facilities in the San Antonio River basin were analyzed. The
sensitivity analysis was conducted to assess the most satisfying strategies
for a regional water quality management system subject to probabilistic standards.
75:05B-003
INTEGRATING CHEMICAL FACTORS WITH WATER AND SEDIMENT TRANSPORT FROM A WATERSHED,
Frere, M.H.
Agricultural Research Service, Chickasha, Oklahoma.
148
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Journal of Environmental Quality, Vol. 4, No. 2, p 12-17. January-March 1975
3 fig, 3 tab, 18 ref.
Descriptors: *Mathematical models, *Water pollution sources, Sediment transport,
Agricultural runoff, *Path of pollutants, Chemicals, Pesticides, Leaching, Soil
erosion, Nutrients, Watershed management, Model studies.
A mathematical model that calculates the movement of a chemical as it is trans-
ported through or off of an agricultural watershed is described. Loss of the
chemical between storms by degradation or volatilization is described by a first-
order rate equation. Simple chromatographic theory is used to describe the
chemical distribution in the soil during leaching, assuming a linear adsorption
to the square root of the distance moved. The concentration at the surface
during the storm is calculated to estimate the amounts lost in runoff water and
with interrill erosion. It is assumed that rill erosion removes the chemical
in proportion to the fraction of the area in rills and to the fraction of the
chemical distribution in the soil intercepted by the rills. Mineralization and
uptake are an additional source and sink for nitrate between storms. Lithium
bromide movement on a microplot was used to examine some features of the model.
75:05B-004
DENITRIFICATION IN LABORATORY SANDY COLUMNS,
Davenport, L.A. JR., Lembke, W.D., Jones, B.A. JR.
Soil Conservation Service, Effingham, Illinois
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 1,
p 95-105, January-February 1975. 8 fig, 2 tab.
Descriptors: *Denitrification, *Laboratory tests, *Soil water movement,
*Groundwater, Water analysis, Chemical reactions, Nitrates, Model studies,
Hydraulic models, Subsurface waters, Confined water, Tile drains, Nutrient
removal, Moisture content.
Nitrate was effectively reduced when methanol was added as a substrate material
to a slowly moving solution in porous columns. Applied nitrate was removed at
a rate of 87.4% during 24 days at 24C and 62% during 27 days at 13C. The use
of sawdust as an oxidizable material had little effect upon nitrate removal.
The flux was maintained at approximately 0.23 cm/hr. The production of gases
which accompanied the denitrification process desaturated the methanol columns
and influenced the flow rate. The breakthrough curver observed indicated that
there may have been signigicantly different effective diffusion coefficient for
nitrate as compared with chloride. The passage of nitrate and chloride through
the columns was accompanied by an increase in redox potential and, in some cases,
a discoloration of the effluent. The removal of a high percentage of nitrate
at relatively large pore velocities was encouraging for the prospect of removing
excess nitrate from soil water in the vivinity of tile drains. While a technique
was not described, it could involve a system for water table control with
additions of substrate material introduced by surface application or deep plowing.
75:05B-005
WATER AND SALT TRANSFERS IN SUTTER BASIN, CALIFORNIA,
Tanji, K.K., Henderson, D.W., Gupta, S.K., Iqbal, M., Quek, A.F.
California University, Davis. Department of Water Science and Engineering
Transactions of the American society of Agricultural Engineers, Vol. 18, No. 1,
p 111-121. January-February 1975. 8 fig, 3 tab, 10 ref.
Descriptors: *Water transfer, *Surface-groundwater relationships, *Saline water
intrusion, *Salt balance, *Hydrogeology, Irrigation effects, Saline water-
freshwater interfaces, Hydrology, Salinity, Irrigation, Water quality, Connate
water, Geohydrologic units, Geology, California, Model studies, Water table,
Return flow.
An analysis of water and salt transfers was conducted in Sutter Basin, California.
The average drainage index for the hydrologic years 1964-1972 was estimated as
149
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0.42+ or -0.08 and the average salt balance index for the hydrologic years
1970-1972 as 2.95+ or -1.25. For the 1970 hydrologic year, the flow-weighted
average surface input of salts (precipitation and irrigation water) was 0.74
tons per ha-m and the surface output (return flow) was 5.08 tons per ha-m.
About 40% of the water and 70% of the salt load in the return flow was estimated
to have originated from subsurface origins, mainly rising connate water.
75:058-006
EFFECTS OF FOREST FERTILIZATION ON TWO SOUTHEAST ALASKA STREAMS,
Meehan, W.R., Lotspeich, F.B., Mueller, E.W.
Environmental Protection Agency, Arctic Environmental Research Laboratory,
College, Alaska 99701.
Journal of Environmental Quality, Vol. 4, No. 1, p 50-55, January-March 1975.
7 fig, 9 ref.
Descriptors: *Water quality, *Alaska, *Nitrogen, Watersheds(Basins), Fertiliza-
tion.
Four streams in southeast Alaska were studied to determine the effects of forest
fertilization with urea on basic productivity and water quality. An initial,
short-term increase in ammonia-nitrogen levels increased and remained high
compared to control stream levels during the year following treatment. Concen-
trations did not approach those considered toxic to aquatic life or unsafe for
human consumption. Changes in biomass of periphyton and benthic fauna as a
result of fertilization were not detected.
75:058-007
THE NEEDS FOR WATER QUALITY MODELS ON AGRICULTURAL WATERSHEDS,
Nicholson, H.P.
Southeast Environmental Research Laboratory, United States Environmental Protection
Agency, Athens, GA 30601
Journal of Environmental Quality, Vol. 4,. No. 1, p 21-23, January-March 1975.
6 ref.
Descriptors: *Model studies, *Watershed management, *Agricultural watersheds,
*Water quality, Water quality control.
Man's agricultural acitvities contribute pollutants to surface and ground water.
Preservation of water quality requires greater effort to control these pollutants
including eroded soil, agricultural chemicals, oxygen-demanding organic wastes,
and sometimes heavy metals and pathogens. Management of nonpoint source agricul-
tural pollutants will require the management of runoff or vertical movement from
the source, the efficient selection and use of appropriate pesticides and fertili-
zers, and the retention of animal wastes and plant residues on the land. Manage-
ment programs should be planned for complete drainage basins making use of exis-
ting conservation programs. Mathematical models now under development will aug-
ment current management practices and will enable the application of computer
technology to prediction of the consequences of agronomic practices.
75:058-008
THE WATERSHED APPROACH TO UNDERSTANDING OUR ENVIRONMENT,
Woolhiser, D.A.
United States Department of Agriculture, Fort Collins, CO 80523
Journal of Environmental Quality, Vol. 4, No. 1, p 19-21, January-March 1975.
2 fig, 25 ref.
Descriptors: *Model studies, *Simulation analysis, *Water quality, *Hydrology,
Watersheds(Basins), Computer models.
Current approaches used in modeling a particular part of the human environment--
the agricultural watershed-are reviewed and questions are raised regarding the
objectives, approaches, and interpretation of agricultural water quality models.
150
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Models—either symbolic (mathematical) or material—are essential to understanding
and predicting environmental phenomena on agricultural watersheds. Models des-
cribing the transport of water, sediment, and chemicals through a watershed sys-
tem can become very complicated and frequently must be simplified. Simplifica-
tions inevitably involve distortion and may make interpretation of model parame-
ters difficult. The use of material models may assist in interpreting the para-
meters of mathematical models.
75:058-009
EFFECTS OF SELECTED HERBICIDES ON BACTERIAL POPULATIONS IN NONTREATED AND TREATED
WATER,
Yazar, O., Shievely, J.M., Camper, N.D.
Clemson University, Clemson, South Carolina, Departments of Biochemistry and
Botany.
Water Resources Bulletin, Vol. 11, No. 2, p 294-299, April 1975. 1 fig, 3 tab,
4 ref.
Descriptors: *Bacteria, *Herbicides, Water supply, Water pollution, Water pollu-
tion effects, Water treatment.
Bacterial populations in nontreated and herbicide-treated waters were subjected
to three different herbicides. Diuron, Dichlobenil, and diquat were added
(100 ml/1) to water samples from two fresh water lakes and two herbicide-treated
ponds. Total numbers of bacteria were monitored. Bacterial populations in fresh
lake water decreased after herbicide additions; however, final populations were
significantly greater than the controls. Similar observations were recorded for
bacteria in dichlobenil-and diuron-treated waters. Selective enrichment is
probably expressed in these experiments.
75:05B-010
NITRATE, PHOSPHATE, AND POTASSIUM MOVEMENT INTO DRAINAGE LINES UNDER THREE SOIL
MANAGEMENT SYSTEMS,
Calvert, D.V-
Florida University, Institute for Food and Agricultural Science, Agricultural
Research Center, P- O. Box 248, Fort Pierce, PL 33450
Journal of Environmental Quality, Vol. 4, No. 2, p 183-186, April-June 1975.
3 fig, 4 tab, 13 ref.
Descriptors: *Nitrate, *Phosphate, *Potassium, *Drainage water, *Drainage,
*Leaching, Lime, Soil investigations, Fertilizers, Irrigation, Agriculture.
Nitrate, orthophosphate, and potassium concentrations in drainage water were de-
termined from subsurface drains installed in shallow-tilled (ST), (15cm);
deep-tilled (DT), (107cm); and deep-tilled and limed (DTL) Florida Oldsmar sand
planted to citrus. Total discharge of NO(3)-N was significantly greater from ST
plots than either DT or DTL plots. Peak concentrations and discharge of fertili-
zer nutrients were shown to be a function of rainfall, irrigation, and timing
of fertilizations. Deeply incorporated limestone applications into the subsoil
tended to increase the NO(3)-N and decrease PO(4)-P discharge over than from deep
tillage alone.
75:05B-011
WATER QUALITY IN IRRIGATED WATERSHEDS,
Branson, R.L., Pratt, P.F., Rhoades, J.D., Oster, J.D.
California University, Riverside 92501. Department of Soil Science Agricultural
Engineering.
Journal of Environmental Quality, Vol. 4, No. 1, p 33-40, January-March 1975.
1 fig, 5 tab, 40 ref.
Descriptors: *Return flow, Irrigation, *Irrigation effects, Drainage water,
Agricultural watersheds, Surface runoff.
151
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Historically, attention to water quality in irrigated watersheds has been focused
on irrigation waters and the relationships of their chemical composition to soil
permeability and crop production. Recently, because of environmental concerns,
it has become necessary to look beyond the quality of irrigation waters and con-
sider also the quality of waters that drain from irrigated lands. Irrigation
agriculture affects drainage-water chemical composition. In turn, drainage waters
can influence the quality of receiving waters which may have a variety of bene-
ficial uses to be protected. The two types of drainage waters from irrigated
lands, surface runoff and subsurface drainage or percolation water, are character-
istically different in composition and chemical concentration. The pollution
potential of subsurface drainage waters, with respect to nitrate and total soluble
salts is a particular concern. Studies of individual field conditions are pro-
viding information that can be extrapolated to show the effects of watershed
management on ultimate water quality in receiving stream or ground water. A new
concept has been developed concerning irrigation water management to minimize the
quantity of salt discharged from irrigated lands and thereby help alleviate water
quality degradation associated with disposal of salt-laden subsurface drainage
waters.
75:05B-012
NITRATE REDUCTION AND NITRITE UTILIZATION BY NITRIFIERS IN AN UNSATURATED HANFORD
SANDY LOAM,
Volz, M.G., Belser, L.W., Ardakani, M.S., McLaren, A.D.
California University, Berkeley, Department of Soils and Plant Nutrition.
Journal of Environmental Quality, Vol. 4, No. 2, p 179-182, April-June 1975.
2 fig, 2 tab, 20 ref.
Descriptors: *Nitrate, *Nitrite, Soil investigations, Nitrification, Soil envi-
ronment, Soil management, Agriculture, Soils.
In order to discern any relationship between added nitrate and microbial growth
in a field plot, a Hanford sandy loam was infiltrated for 5 weeks at a rate of
5 cm/day with a solution containing 100 ppm-N and 1.25 meq/liter Cl(-) as KNO(3)
and CaCl(2) respectively. Nitrate -N, NO(2){-)-N and Cl(-) concentrations in
soils solution were determined and corresponding counts of nitrate reducers,
denitrifiers, and NH(4)(+)- and NO(2)(-)-oxidizer populations were made. Ratios
of measured to applied concentrations for both N0(3)(-)-N and Cl(-) were nearly
identical in all solution samples taken from the unsaturated soil profile, i.e.,
nitrate reduction was not pronounced and NO(2)(-)-N was less than 1 ppm.
75:058-013
PHOSPHORUS MOVEMENT IN SOILS; SOIL-ORTHOPHOSPHATE REACTION KINETICS,
Novak, L.T., Adriano, D.C.
Cleveland State University, Cleveland, Ohio. Chemical Engineering Department.
Journal of Environmental Quality, Vol. 4, No. 2, p 261-266, April-June 1975.
5 fig, 3 tab, 20 ref, 1 append.
Descriptors: *Model studies, 'Adsorption, *Phosphorus, *Waste water treatment,
Soil water, Soil chemical properties, Soil chemistry, Kinetics.
This paper presents four models to describe the kinetics of P adsorption-desorp-
tion reactions in soils. The mass transfer model, Langmuir kinetics model, and
Langmuir-Himshelwood models were developed and compared with phosphate adsorption
data on a soil obtained by batch-shaken flask experiments. For P adsorption
times up to 3 hours, the mass transfer and Langmuir kinetics model gave a slightly
better fit of the experimental data. These kinetic data probably represent an
upper bound for unsaturated flow in soils.
75:058-014
THE IMPACT OF MOLYBDENUM-ENRICHED IRRIGATION WATER ON AGRICULTURAL SOILS NEAR
BRIGHTON, COLORADO,
Jackson, D.R., Lindsay, W.L., Heil, R.D.
Colorado State University, Fort Collins, Department of Agronomy.
152
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Journal of Environmental Quality, Vol. 4, No. 2, p 223-229, April-June 1975
10 fig, 4 tab, 25 ref.
Descriptors: *Irrigation water, *Molybdenum, *Soil chemistry, Soil investiga-
tions, Agriculture, Colorado, Alfalfa.
The Mo concentration in water, soils, and alfalfa was monitored for one growing
season to determine the impact of using Mo-enriched irrigation water near
Brighton, Colorado. The concentration of Mo in irrigation water in this area
ranged from 27 to 213 ppb. A significant increase of Mo concentration in
alfalfa and available soil Mo was observed at one site irrigated with water con-
taining 213 ppb Mo. The Mo concentration in the alfalfa at this site increased
during the gmwing season from 4.3 to 7.2 ppm. This level is below the 10 ppm
level considered toxic to livestock. Plant Mo was highly correlated (r=0.94)
with resin-extractable Mo in a greenhouse experiment using soils from three
of the- field sites. Field results were less satisfactory (r=0.51), partially
due to limited indigenous levels of Mo in the soils. A simulation model was
used to assess the potential hazards of irrigating with water containing from
0 to 600 ppb Mo. The impact of Mo on the Brighton area during one growing sea-
son was minimal in relation to uptake of Mo by plants. Further studies are
necessary to assess the long term effects of Mo accumulation in soils and irri-
gated with Mo-enriched waters.
75:058-015
CALCULATED DRAINAGE WATER COMPOSITONS AND SALT BURDENS RESULTING FROM IRRIGATION
WITH RIVER WATERS IN THE WESTERN UNITED STATES,
Oster, J.D., Rhoades, J.D.
United States Department of Agriculture, Agricultural Research Service, River-
side, CA
Journal of Environmental Quality, Vol. 4, No. 1, p 73-79, January-March 1975.
4 fig, 3 tab, 25 ref.
Descriptors: *Model studies, *Simulation analysis, Lysimeters, Alfalfa, Leach-
ing, Return flow, Salinity, Saline water, Irrigation water.
Drainage water compositions were calculated with a computer simulation model
from irrigation water compositons, leaching fractions, aragonite and gypsum
solubilities, and measured partial pressure of CO(2). The calculated compositions
were compared with measured values obtained from lysimeters filled with Pachappa
soil, cropped with alfalfa, and irrigated with eight synthetic waters typical
of rivers in the western U.S. Linear regression analysis, of predicted vs.
measured values for Na(+) and SP4(2-) concentrations, sodium-adsorption-ratio,
electrical conductivity, and salt burden resulted in essentially one-to-one re-
lationships. The gain in salt burden of drainage water at high leaching fractions
due to mineral dissolution was adequately described by assuming the soil solution
was saturated with respect to aragonite. Some evidence for Mg(2+) precipitation
was found. The utility of the simulation model is demonstrated for evaluating
the salinity, sodicity, and pollution hazards of irrigation waters.
75:05B-016
REGIONAL SEWERING AND GROUNDWATER QUALITY IN THE SOUTHERN SAN JOAQUIN VALLEY,
Schmidt, K.D.
Water Resources Bulletin, Vol. 11, No. 3, p 514-525, June 1975. 4 fig, 9 ref.
(See 75:05C-001)
75:05B-017
THE NITROGEN BALANCE OF ARCTIC TUNDRA: PATHWAYS, RATES, AND ENVIRONMENTAL
IMPLICATIONS,
Barsdate, R.J., Alexander, V.
Alaska University, Fairbanks, Department of Marine Science.
Journal of Environmental Quality, Vol. 4, No. 1, p 111-117, January-March 1975.
3 fig, 5 tab, 43 ref.
153
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Descriptors: *Nitrogen, *Alaska, *Leaching, *Denitrification, Ecosystems
The magnitude of the inputs and exports of nitrogen was estimated for the tundra
ecosystem at Barrow, Alaska. Based on new data and on previous investigations,
annual input of nitrogen from all sources was 92.4 mg N/m(2) per year, with the
most important sources being nitrogen fixation (75%) and ammonia in summer rain
(18%). The low input of nitrogen by rain and snow results from both low annual
precipitation and extremely low concentrations of nitrogen compounds in pre-
cipitation. Despite the meager nitrogen supply, the estimated retention is over
80% of the input reflecting insignificant leaching due to the impermeable perma-
frost substrate, low precipitation, and restricted lateral movement of water
over and through the nonfrozen soils. Denitrification also is low, at least
partially due to nutrient deficiency. Interpretations of these data in respect
to the sensitivity of the environment to perturbations, suggest that resource
development or other activities which would have minor or negligible effects in
temperature latitudes, could alter substantially the nitrogen balance of this
arctic ecosystem.
75:05B-018
A GALERKIN-FINITE ELEMENT TECHNIQUE FOR CALCULATING THE TRANSIENT POSITION OF
THE SALTVJATER FRONT,
Segol, G., Finder, G.F., and Gray, W.G.
Princeton University, N.J. Department of Civil and Geological Engineering.
Water Resources Research, Vol. 11, No. 2, p 343-347, April 1975. 7 fig, 13
ref.
Descriptors: *Saline water intrusion, *Groundwater movement, *Finite element
analysis, *Mathematical models, Simulation analysis, Mass transfer, Path of
pollutants, Convection, Mixing.
The set of nonlinear partial differential equations that describe the movement
of the saltwater front in a coastal aquifer may be solved by the Galerkin-finite
element method. Pressure and velocities are obtained simultaneously in order
to guarantee continuity of velocities between elements. A layered aquifer may
be modeled either with a functional representation of permeability or by a
constant value of permeability over each element.
75:058-019
AN EMPIRICAL METHOD OF ESTIMATING THE RETENTION OF PHOSPHORUS IN LAKES,
Kirchner, W.B., and Dillon, P.J.
Toronto University. (Ontario). Department of Zoology.
Water Resources Research, Vol. 11, No. 1, p 182-183, February 1975. 1 fig, 1 tab,
7 ref.
Descriptors: *Nutrients, *Phosphorus, *Model studies, *Lakes, Water balance,
Surface waters, Hydrologic systems, *Canada, *Estimating.
The relationship between phosphorus retention and several other lake and water-
shed parameters was examined for 15 Canadian lakes. Multiple linear regressions
were first attempted, but the model developed from the best correlation would
have required extensive field measurements for accurate predictive use. There-
fore, nonlinear relationships were investigated, resulting in a model relating
the areal water load q sub s in meters per year of a lake to its phosphorus
retention coefficient R sub p. R sub p = p.426 exp(-0.271 q sub s) + 0.574
exp (-0.00949 q sub s). This model was found to be theoretically sound, and the
predicted and measured values were in close agreement with a correlation coeffi-
cient of 0.94. The apparently closer relationship of the phosphorus retention
coefficient to areal water load than to volumetric water load (or water renewal
time) was not explainable.
75:05B-020
ON THE EFFICIENT ALLOCATION OF ENVIRONMENTAL ASSIMILATIVE CAPACITY: THE CASE
OF THERMAL EMISSIONS TO A LARGE BODY OF WATER,
154
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Scherer, C.R.
California University, Los Angeles. Department of Engineering Systems.
Water Resources Research, Vol. 11, No. 1, p 180-181, February 1975. 3 fig, 9 ref.
Descriptors: *Economic efficiency, ""Thermal capacity, "Lakes, *Water quality
control, "Temperature, Standards, Environment, Heated water, Effluents, Flow
rate, Costs, Ports, Size, Cooling towers, Powerplants, Marginal costs, Mathemati-
cal models, Systems analysis, Methodology, *Waste assimilative capacity,
*Thermal pollution.
Considered is the economically efficient level of environmental assimilative
capacity in the case of thermal electric rejected heat discharges to large lakes
subject to temperature standards. A mathematical model relating heated effluent
flow rate and 'near-field1 temperature is used to determine maximum diffusor
port size. Diffusor costs are developed as a function of discharge velocity,
port size being given. Cooling tower costs are also developed for comparison
with diffusor costs in selecting an optimal level of thermal assimilative capacity.
The relationship between this selection process and optimal power plant siting
models is outlined. It is shown that arbitrarily fixing discharge velocity at
some 'practical' level will tend to bias the results of these siting models to-
ward overly conservative use of thermal assimilative capacity. This means,
available capacity will not be fully exploited, and the cost of a given level of
power output will be greater than is necessary.
75:05B-021
WATER QUALITY CHANGES RELATED TO THE DEVELOPMENT OF ANAEROBIC CONDITIONS DURING
ARTIFICIAL RECHARGE,
Wood, W.W., and Bassett, R.L.
Geological Survey, Lubbock, Texas.
Water Resources Research, Vol. 11, No. 4, p 553-558, August 1975. 6 fig, 3 tab,
15 ref.
Descriptors: *Artificial recharge, *Water spreading, *Chemical reactions,
*Anaerobic bacteria, *Texas, Groundwater recharge, *Water quality, Infiltration
rates, Gravitational water, Soil properties, Sulfates, Bicarbonates, Hydrogen
ion concentration, Geology, Data collections, Chemical analysis, *Water reuse.
Artificial recharge basins or spreading sites commonly exhibit reductions in
infiltration rates after prolonged periods of submergence. This loss in infil-
tration rate has often been shown to be associated with a large population of
anaerobic or facultative anaerobic bacteria in the material underlying the basin
floor. An artificial recharge experiment in a spreading basin at Lubbock, Texas,
showed a significant change in the chemical quality of recharged water that was
associated with the growth of anaerobic bacteria. Sulfate-reducing bacteria re-
duced the sulfate concentration of the recharge water at this location by 80 mg/
liter, and the pH decreased 1 unit during the same time period. The change in
chemical quality occurred suddenly and corresponded to a dramatic decrease in the
infiltration rate in the basin. These observations on the chemical changes in
recharged water make it possible to differentiate between anaerobic bacteria and
other causes of reduced hydraulic conductivity in this recharge basin. The
anaerobic conditions appear to start at depth and work toward the surface, thereby
suggesting a process that involves adsorption of organic material and consumption
of dissolved oxygen with depth.
75:056-022
URBAN LAWN INFILTRATION RATES AND FERTILIZER RUNOFF LOSSES UNDER SIMULATED RAIN-
fall,
Kelling, K.A., and Perterson, A.E.
Ball State University, Muncie, Indiana. Department of Natural Resources.
Soil Science Society of American Proceedings, Vol 39, No. 2, p 348-352, March-
April, 1975. 1 fig, 4 tab, 25 ref.
Descriptors: *Path of pollutants, *Urban runoff, "Fertilizers, *Water pollution
sources, "Infiltration, "Rainfall-runoff relationships, Nutrients, Pollutants,
155
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Vegetation effects, Storm runoff, Eutrophication, Soil-water-plant relationships,
Soils, Infiltrometers, Surface waters, Simulated rainfall.
Infiltration runoff measurements were made on nine urban lawns by using a sprink-
ling infiltrometer in conjunction with the application of a complete fertilizer
at three rates. The amounts of inorganic N,P, and K removed with the runoff
water were determined. Results of the infiltration measurements show that the
presence of textural and compaction discontinuities within the soil profile,
formed during building and lawn construction, was probably the greatest factor
affecting infiltration. Where these discontinuities were distinct, water intake
was reduced to about 35% of that for a lawn with an undisturbed profile. For
lawns with similar infiltration characteristics, a first order relationship
appeared to exist between amounts of fertilizer applied and amounts lost. A
second order equation, however, best described the relationship between percent
of applied fertilizer in the runoff and 90-min cumulative infiltration. When
the simulated storm was applied immediately after fertilizer application, fertil-
izer losses averaged 10.6%; however, when fertilizer application was followed
by recommended watering before the intense storm, average losses were reduced to
1.7% of the amount applied.
75:05B-023
NUTRIENT TRANSPORT IN SURFACE RUNOFF AS INFLUENCED BY SOIL COVER AND SEASONAL
PERIODS,
Burwell, R.E., Timmons, D.R., Holt, R.F.
Agricultural Research Service, Morris, Minnesota. North Central Soil Conservation
Research Center.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 523-528, May-June,
1975. 5 tab, 14 ref.
Descriptors: *Nutrients, *Runoff, *Sediments, Nitrogen, Phosphorus, Potassium,
Snowmelt, Precipitation(Atmospheric), Erosion, Agriculture, Chemistry of precip-
itation, Seasonal, Fertilizers, Surface runoff, Crops, On-site investigations,
*Minnesota.
Nitrogen(N), phosphorus (P), and potassium (K) losses in surface runoff water
and sediment were determined for five soil cover conditions on a Barnes loam
soil in west-central Minnesota. The five soil cover conditions studied were:
(1) continuous clean-cultivated fallow, (2) continuous corn, (3) corn in rotation,
(4) oats in rotation, and (5) hay in rotation. Losses of water, sediment, and
nutrients were determined for three seasonal periods: (1) critical runoff peri-
od caused by melting snow and ice, (2) critical erosion period from corn planting
to 2 months later, and (3) noncritical runoff-erosion period exclusive of periods
1 and 2. Much of the annual sediment and nutrient losses occurred during the
critical erosion period. Snowmelt runoff accounted for much of the annual water
and soluble nutrient losses. Average annual quantities of NH4-N and NO3-N
contributed by precipitation exceeded the annual losses in surface runoff, but
ortho-P losses in surface runoff were greater than the amount contributed by
precipitation.
75:05B-024
COMPARISON OF TWO PREDICTIVE NONEQUILIBRIUM ONE-DIMENSIONAL MODELS FOR PHOSPHORUS
SORPTION AND MOVEMENT THROUGH HOMOGENEOUS SOILS,
Enfield, C.G., Shew, D.C.
Robert S. Kerr Environmental Research Laboratory, Ada, OK.
Journal of Environmental Quality, Vol. 4, No. 2, p 198-202, April-June, 1975.
5 fig, 1 tab, 21 ref.
Descriptors: *Phosphorus, *Sorption, *Diffusion, *Simulation analysis, *Model
Studies, Kinetics, Soil chemistry, Soil investigations, Agriculture.
Two models were tested for their ability to predict phosphorus breakthrough
curves. The basic difference between the two models is the method of describing
the kinetics of sorption. It was found, when comparing theoretically predicted
156
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breakthrough curves with experimental breakthrough curves, that the model using
a kinetic equation produced a better fit to the experimental data than a first
order rate equation.
75:053-025
FACTORS INFLUENCING NITRATE TRANSFORMATIONS IN SEDIMENTS,
Terry, R.E., Nelson, D.W.
Indiana Agricultural Experiment Station.
Journal of Environmental Quality, Vol. 4, No. 4, p 549-554, October-December 1975.
7 tab, 16 ref.
Descriptors: *Nitrification, *Denitrification, *Eutrophication, Nitrates,
Temperature, Sediment.
The effects of environmental and procedural factors (e.g., aeration, size of
sample water/sediment ration, nitrate concentration, glucose addition, tempera-
ture, and sterilization) on denitrification in lake and reservoir sediments
were evaluated by incubation nitrate-amended natural sediments in the laboratory -
The standard laboratory procedure adopted for denitrification studies involved
the incubation of small samples of sediment (undried) after addition of a nitrate
solution. Denitrification in sediment-water samples was not enhanced by contin-
uously purging samples with helium to create artificial anaerobic conditions.
Even though glucose additions enhanced denitrification by 25 to 30%, unamended
sediments contained sufficient available organic-D for near maximal rates of
denitrification. Denitrification in sediments increased with increasing temper-
ature over the range of 5 to 23C. However, significant denitrification occurred
at temperatures as low as 5C. The evaluation of factors affecting denitrifica-
tion in sediment show that the environmental conditions likely to exist in natural
sediments are suitable for denitrification. Anaerobiosis and the high organic
matter of most sediments create an ideal environment for microbial denitrifica-
tion. The levels of nitrate in surface water may in part be controlled naturally
by denitrification in sediments.
75:05B-026;
THE TIME STABILITY OF DISSOLVED MERCURY IN WATER SAMPLES-II. CHEMICAL STABILIZA-
TION,
Avotins, P., Jenne, E.A.
United States Department of the Interior, Geological Survey.
Journal of Environmental Quality Vol. 4 No. 4 p 515-519. October-December 1975.
8 fig, 2 tab, 12 ref.
Descriptors: *Bacteria, *Mercury, Water quality, Water pollution, Water pollution
sources, Water, Water pollution effects.
Bacteria were found to be the principal cause of instabiltiy of mercury in labora-
tory solutions. The volatilization loss rate increased rapidly after a variable
lag period and then leveled off with increasing time. The marked reduction in
the loss rate of mercury is a result of its combination with bacterial cells
and metabolites. Reagents which either oxidize or solubilize organics removed
mercury most effectively from sample containers in which mercury-bearing water
had been stored. A small amount of mercury was found to have diffused into the
polyethylene bottles. Solute mercury was most effectively stabilized in labora-
tory solutions and water samples with 0.05% KMnO4 without acidification.
75:056-027
MIGRATION OF SALT FROM FEEDLOT WASTE AS AFFECTED BY MOISTURE REGIME AND AGGREGATE
SIZE,
Amoozegar-Fard, A., Fuller, W.H., Warrick, A.W.
Arizona Agricultural Experiment Station.
Journal of Environmental Quality, Vol. 4 No. 4 p 468-472. October-December 1975.
2 fig, 6 tab, 14 ref.
157
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Descriptors: *Salinity, *Return flow, *Feed lots, Water management(applied),
Water quality control, Soil moisture.
The migration of salt from three different aggregate sizes of feedlot manure
under three moisture regimes was evaluated. The three sizes were small (to
pass a 40-mesh sieve), medium (o.9 cm in diameter, 2.25 cm in length), and large
(4.8 cm in diameter, 2.6 cm in length). The three moisture regimes were: (i)
12 hours saturation, 12 hours drainage by gravity, this step was repeated five
times; (ii) 12 hours saturation, 12 hours drainage by gravity, 48 hours oven
drying at 60C, also repeated five times; and (iii) continuous leaching for 60
hours at a constant rate. After each 12 hour saturation period the leachates
were collected and the electrical conductivity (EC), pH, and concentrations of
K, Na, Ca, Mg, NH4, NO3, Cl, S,P, and eight trace elements determined.
75:056-028
A SIMULATION MODEL OF BIOPHYSIOCHEMICAL TRANSFORMATIONS OF NITROGEN IN TILE-
DRAINED CORN BELT SOIL,
Duffy, J., Chung, C., Boast, C., Franklin, M.
National Science Foundation.
Journal of Environmental Quality, Vol. 4, No. 4, p 477-486, October-December 1975.
8 fig, 1 tab, 30 ref.
Descriptors: *Model studies, *Simulation analysis, *Nitrogen, *Corn, *Drainage,
Water quality. Nitrification, Denitrification, Evapotranspiration, Crop response.
A computer simulation model of nitrogen transformations and transport in soil
in a Corn Belt field was developed to predict nitrate concentrations in tile
effluent as a. function of farm management practices and climatic conditions.
Water flow in the unsaturated and saturated zones, evapotranspiration, and nitro-
gen flow due to mass flow, dispersion, and diffusion are simulated along with
nitrogen transformations of mineralization, immobilization, nitrification, and
denitrification. Growth of corn and soybeans is included. Predicted values of
tile water flow, water table height, nitrate-nitrogen concentrations in the soil
water profile and in the tile effluent compared favorably to measure values for
filed for 1972; also, predictions of nitrate-nitrogen concentrations in tile
effluent for 1970-71 agree well with actual data.
75:05B-029
HEAT DISPpSAL IN WATER ENVIRONMENT,
Harleman, "D.R.F.
Massachusettes Institute of Technology, Cambridge, Massachusettes, Laboratory
for Water Resources and Hydrodynamics.
Journal of the Hydraulics Division, Vol. 101, No. HY9, p 1117-1138, September
1975. 1 fig, 21 ref, 2 append.
Descriptors: *Heated water, Heat transfer, Heating, Water pollution, Water
quality.
A number of analytical and experimental techniques for predicting water tempera-
ture distributions due to waste heat discharges have been examined. Predictive
techniques are needed in the preparation of environmental impact statements for
preoperational site studies in order to evaluate the economic and environmental
costs of alternative cooling water systems. These techniques are also useful
in post-operational studies, inasmuch as field observations can be carried out
only under a limited number of ambient conditions. Mathematical models can be
used in interpretating field data and for providing additional information for
receiving water conditions other than those measured. The use of mathematical
or physical models, or both, for the planning and design of field monitoring pro-
grams has received relatively little attention. It is suggested that a consider-
able amount of time and expense could be saved by making use of temperature
prediction models in planning field surveys.
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75:056-030
NATURAL (15)N ABUNDANCE IN SOIL, LEAVES, AND GRAIN AS INFLUENCED BY LONG TERM
ADDITIONS OF FERTILIZER N AT SEVERAL RATES,
Meints, V.W., Boone, L.V., Kurtz, L.T.
Illinois University, Department of Agronomy and Illinois Agricultural Experiment
Station, Urbana, IL.
Journal of Environmental Quality, Vol. 4 No. 4, p 486-490, October-December 1975.
4 fig, 1 tab, 20 ref.
Descriptors: *Fertilization, *Fertilizers, *Nitrogen, *Corn, *Soybeans, Crop
response.
Soil, leaf, and grain natural (.15)N abundance was measured in corn and soybean
plots which had received various rates of fertilizer N for 20 years. Soil (15)N
abundance did not significantly reflect the amount of fertilizer N applied and
should not be used to estimate fertilizer N additions. Corn leaf and grain (15)N
abundance reflected additions of fertilizer N only at low rates of fertilizer N
applied and should not be used to estimate fertilizer N additions. Corn leaf
and grain (15)N abundance reflected additons of fertilizer N only at low rates of
fertilizer N applied. Soybean leaf (15)N abundance reflected a decrease in
symbiotic N fixation with additional increments of fertilizer N applied.
75:05B-031
RELATIONSHIPS BETWEEN SORPTION AND DESORPTION OF PHOSPHORUS BY SOILS,
Ballaux, J.C., Peaslee, D.E.
Institute of Tropical Agriculture, Ibadan, Nigeria.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 275-278, March-
April 1975. 1 fig, 7 tab, 22 ref.
Descriptors: *Sorption, *Phosphorus, *Soil properties, Soil investigations,
Soil chemistry, Soils.
Relationships between the sorption and desorption of P were investigated for five
soils ranging in clay content from 16 to 51%, Langmuir adsorption isotherms for
some soils were curvilinear when the "P concentration in the equilibrium solution
was >10micro-g/ml. To evaluate sorption at higher concentrations of P, values
of adsorption maxima (b) and indices of bonding energy (k) were estimated from
tangents to six segments of each isotherm. Within each soil, the six pairs of b
and k values were related according to the equation k=(a/b)(n), where n was a
unique characteristic for each soil.
75:05B-032
SORPTION OF SULFUR DIOXIDE BY CALCAREOUS SOILS,
Yee, M.S., Bohn, H.L., Miyamoto, S.
Arizona University, Tucson, 85721
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 268-270. March-
April 1975. 5 fig, 3 tab, 14 ref.
Descriptors: *Sorption, *Sulfur, *Sulfur compounds, *Calcareous soils, Soil
chemistry, Soil chemical properties, Pollutants.
The capacities and rates of calcareous soils to sorb SO2 were measured by a steady-
state method in which a stream of air plus S02 passed rapidly through the soil.
At room temperature, air-dry calcareous soils were saturated with S02 within 10
to 15 min from a dry gas stream. The sorption capacities, 0.4 to 1.6 g of S/100
g of soil at 0.34% S02 in air, increased with SO2 concentration and specific
surface of the soils. Moisture in the air and/or soils increased the S02 sorption
capacities to 0.8 to 6.4 g of S/100 g, approximately equivalent to the acid-
titratable basicities, but saturation required several hours. The initial sorption
rate ranged from 0.06 to 0.29% S/min in the moist soils.
EFFECT OF ANION EXCLUSION ON THE MOVEMENT OF CHLORIDE THROUGH SOILS,
159
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Appelt, H., Holtzclaw, K., Pratt, P.F.
Racultad de Ciencias Quimicas, Universidad de Chile, Casilla 233, Santiago,
Chile.
Soil Science Society of America Proceedings, Vol. 39, No. 2, p 264-267, March-
April 1975. 2 fig, 4 tab, 14 ref.
Descriptors: *Soil chemistry, *Chlorides, *Soil chemical properties, Soil
investigation, Soil properties, California, Cation exchange.
The effects of anion exclusion on the movement of chloride through soils was
studied using a variety of subsurface soil samples from southern California. The
data reported, suggest that the nature of the clay mineral, clay content, satu-
ration percentage and iron ioxide content together with the cation-exchange
capacity are important soil characteristics related to the volume of exclusion.
General equations that are based only on specific charge, seem to be oversimpli-
fications. Another serious limitation of general equations obtained under labor-
atory conditions is their extrapolation to field conditions. The high variability
regarding salt distribution commonly found in the field, makes the use of correc-
tion factors, such as volume of exclusion, of limited value. More studies under
field conditions are necessary before quantitative predictions can be made using
general equations obtained with disturbed soil samples in the laboratory.
75:05B-034
LONGITUDINAL DISPERSION IN NATURAL CHANNELS,
Day, T.J.
Geological Survey of Canada, Ottawa (Ontario).
Water Resources Research, Vol. 11, No. 6, p 909-918, December 1975. 11 fig, 5
tab, 31 ref.
Descriptors: *Dispersion, *Channel flow, Natural flow, *Tracers, *Mixing, Flow,
Flow profiles, *Path of pollutants, Convection, Movement, Water pollution, Channels,
On-site investigations.
The longitudinal dispersion of fluid particles in natural channels was investiga-
ted in an extensive series of experiments in small mountain streams (New Zealand).
These experiments extended over a maximum distance of 2,250 m, a mean velocity
range of 0.32-1.57 m/s, and a mean flow width range of 2.7-21.8 m. It was conclu-
sively shown for these channels and others as well that the spread or standard
deviation of an initially concentrated mass increases linearly with distance and
not as its square root, as is necessary for the application of Taylor's mixing
model. One consequence of the linearity is an ever-increasing dispersion coeffi-
cient along the channel. It was also shown that the time-concentration curve of
a dispersing tracer mass maintains a persistent asymmetry. This persistent asym-
metry and the continued linear spreading appeared to be characteristic of disper-
sion in natural channels and as such showed the inadequacies of applying Taylor's
analysis.
75:05B-035
NEW TRITIUM DATA ON MOVEMENT OF GROUNDWATER IN WESTERN FRESNO COUNTY, CALIFORNIA,
Poland, J.F., Stewart, G.L.
Geological Survey, Sacramento, California.
Water Resources Research, Vol. 11, No. 5, p 716-724, October 1975, 8 fig, 2 tab,
10 ref.
Descriptors: *Water pollution sources, *Tritium, *Groundwater, *Path of pollutants,
*California, Data collections, Sampling, Water wells, Nuclear explosions, Radio-
activity effects, Evaluation.
As a result of thermonuclear explosions that began in 1954, tritium concentrations
in precipitation and streamflow in the northern hemisphere have fluctuated greatly.
Well waters along two traverse lines in western Fresno County, California were
sampled in 1963 and tested for tritium concentration. Haskell et al, (1966)
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estimated from the apparent thermonuclear tritium concentrations that ground-
water had moved westward in the lower waterbearing zone at a maximum velocity of
14-16.5 miles (23-27km) in 9 years. The maximum velocities and permeabilities
estimated from the 1963 sampling were about an order of magnitude greater than
the velocities and permeabilities suggested by prior hydrologic and geologic
evidence. Consequently, in 1966-1970 the U.S. Geological Survey sampled and test-
ed the tritium concentrations of well waters along the same two traverses but also
extended the sampling eastward. On the basis of these analyses it is concluded
that (1) thermonuclear tritium had not invaded the lower zone by 1970 within the
extent of the 1963 sampling and (2) although the maximum westward movement of
groundwater in the lower zone from 1955 to 1970 is indeterminate, it has been less
than 4 miles (6.5 km) from the recharge area in 15 years.
75:058-036
SOLUTE TRAVEL-TIME ESTIMATE FOR TILE-DRAINED FIELDS: II. APPLICATION TO EXPERI-
MENTAL STUDIES,
Jury, W.A.
California University, Riverside. Department of Soil Science and Agricultural
Engineering.
Soil Science Society of America Proceedings, Vol. 39, No. 6 p 1024-1028, November-
December 1975. 3 fig, 5 tab, 11 ref.
Descriptors: *Leaching, *Water quality, *Effluents, *Drainage water, *Solutes,
*Path of pollutants, Pollutants, Mathematical models, Forecasting, Wastes, Fertil-
izers, Water pollution sources, Tiles, Drains, Excess water(Soils), Monitoring,
Data collections, Legislation.
The model of Jury (1975) for estimating travel time from surface application to
point of discharge for tile-drained fields was applied to data from published
studies of tile-drain effluent concentrations and solute flux. In all systems the
observed values were consistent with model calculations, and in circumstances
where an exact comparison was possible the agreement between measured and predicted
values was very good. Measures proposed for improving water quality by requiring
standards for effluent discharge levels were discussed and criticized, and model
simulations of projected monitoring policies of typical field systems were used
to demonstrate the potential for misinterpreting the relationship between surface
inputs and output levels.
75:05B-037
SOLUTE TRAVEL-TIME ESTIMATES FOR TILE-DRAINED FIELDS: I. THEORY,
Jury, W.A.
California University, Riverside. Department of Soil Science and Agricultural
Engineering.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1020-1024, November-
December 1975. 6 fig, 14 ref.
Descriptors: *Leaching, *Water quality, *Effluents, *Drainage water, *Solutes,
*Path of pollutants, Pollutants, Mathematical models, Forecasting, Wastes, Fertil-
izers, Water pollution sources, Tiles, Drains, Excess water(Soils) .
A model based on papers by D. Kirkham (1949, 1958) was proposed for calculating
solute travel times and effluent water quality for tile-drained soil profiles for
cases of ponded and unsaturated surface water input. Variables required for
utilization of the model were drain spacing, depth of tile, depth to impermeable
zone, soil porosity, and mean discharge rate over the time of study. By using
dimensionless variables a characteristic travel-time parameter was introduced
which represented a system and allowed the model calculations to be summarized on
a single graph. Simulations were run for cases of miscible displacement, step-
function surface solute input, and periodic surface solute input; differences
between ponded and unsaturated leaching were discussed for tile systems,
75:058-038
IDENTIFICATION IN NONLINEAR, DISTRIBUTED PARAMETER WATER QUALITY MODELS,
161
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Yih, S.M., Davidson, B.
Rutgers - The State University, New Brunswick, New Jersey. Department of Chemical
and Biochemical Engineering.
Water Resources Research, Vol. 11, No. 5, p 693-704, October 1975. 9 fig, 6 tab,
47 ref.
Descriptors: *Model studies, *Water quality, *Estuarine environment, *New Jersey,
Water pollution control, Estuaries, Salinity, Tides, Water pollution, *Path of
pollutants, *Delaware River, Dispersion.
Systematic and efficient numerical algorithms were developed and applied to the
identification of unknown functional parameters in nonlinear estuarine water
quality models based on input-output measurements. As an illustration of the
methodology the longitudinal dispersion coefficient was identified from an intra-
tidal, time-varying, variable area, salinity intrusion model by using both simu-
lated data and actual data from the Delaware River estuary. A comparison among
three proposed algorithms through extensive simulation research showed that
Marquardt's algorithm emerged as the most efficient one. Effects of noise content
and the number of data measurement locations on parameter sensitivity were inves-
tigated. Actual monitored salinity data for 3 days in September 1965 were tested
in the saline portion of the Delaware River estuary. The spatial variation of
the longitudinal dispersion coefficient for this period was estimated. The results
obtained indicated that the methodology is generally applicable. It represents
a different and supplementary alternative to the methods based on analytical
predictions and empirical correlations.
75:05B-039
NITRATE, PHOSPHORUS, AND SULFATE IN SUBSURFACE DRAINAGE WATER,
Baker, J.L., Campbell, K.L., Johnson, H.P., Hanway, J.J.
Iowa State University, Ames. Department of Agricultural Engineering.
Journal of Environmental Quality. Vol. 4, No. 3, p 406-412, July-September,
1975. 2 fig, 4 tab, 17 ref.
Descriptors: *Eutrophication, *Tile drainage, *Groundwater, *Nutrients, Nitrates,
Nitrogen, Sulfates, Phosphorus, Phosphates, Subsurface drainage. Fertilization,
Flow rates, Agriculture, Iowa.
To determine nutrient losses associated with subsurface drainage water and the
effect fertilization rate has on these losses, measurements were made of flow,
nitrate-nitrogen, phosphate-phosphorus, total phosphorus, and sulfate-sulfur in
subsurface drainage water from tile-drained cropland in Iowa. Annual nutrient
losses were variable; phosphorus, sulfate-sulfur, and nitrate-nitrogen losses
ranged from 0 to 0.04, 0 to 32, and 0 to 93 kg/ha, respectively, and were depen-
dent on amount of water lost. Because of low phosphorus concentrations, losses
with subsurface drainage water were insignificant compared to losses associated
with surface runoff. Sulfate-sulfur and nitrate-nitrogen concentrations appeared
to be inversely related. Tile drainage water with consistently high nitrate-
nitrogen relative to surface runoff was believed responsible for high nitrate-
nitrogen contents sometimes found in rivers draining central Iowa. Nitrate from
saturated and unsaturated soil indicated that water waves or pulses with different
nitrate-nitrogen concentrations move through the soil causing variations in sub-
surface drainage water with time and flow rate. The large amounts of nitrate-
nitrogen lost from some tile drains with modest fertilization and variations in
tile drains make it impossible to ascribe nitrate-nitrogen loss to fertilizers
alone. Nitrate-nitrogen loss represents an economic and energy waste as well as
an environmental hazard.
75:058-040
PHOSPHORUS IN SURFACE RUNOFF FROM A DECIDUOUS FOREST,
Singer, M.J., Rust, R.H.
Minnesota University, St. Paul. Department of Soil Science.
Journal of Environmental Quality, Vol. 4, No. 3, p 307-311, July-September 1975.
4 fig, 2 tab, 26 ref.
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Descriptors: *Phosphorus, *Rainfall-runoff relationships, *Eutrophication,
*Surface runoff, *Deciduous forests, Minnesota, Snowmelt, Forest soils. Soil ero-
sion.
Phosphorus loss in surface runoff from a deciduous forest ecosystem was determined
in Lake Minnetonka, Minnesota, watershed. Runoff was highest in March due to mel-
ting snowpack, in May due to continuous heavy rains, and in July due to intense
short duration rains on dry soil. Runoff in other months was related to rain-
fall amount, intensity, and soil moisture. Most small storms did not precipitate
runoff. Intense storms often exceeded the soil's infiltration rate, dislodged
soil particles, with consequent runoff. The canopy reduced precipitation intensity
and amounts reaching the soil surface. Forest litter had a large water holding
capacity and rapid infiltration rate which protected soil mineral from direct
rainfall impact and reduced runoff. Any melting snow in December-January saturated
lower snow layers but did not create runoff. Spring runoff volume was determined
by snowpack depth, water content, air temperature, and presence or absence of
frozen soil surfaces. Yearly runoff volume and timing varied greatly. March
runoff had more phosphorus but in other months phosphorus concentration was in-
versely related to runoff volume. Sediment phosphorus loss was linearly correlated
with maximum precipitation. Care should be given in extrapolating the findings
for the rate of phosphorus loss from the test plot to an entire forest.
75:05B-041
NITRATE MOVEMENT AND ITS DISTRIBUTION IN THE SOIL PROFILE OF DIFFERENTIALLY
FERTILIZED CORN WATERSHEDS,
Schuman, G.E., McCalla, T.M., Saxton, K.E., Knox, H.T.
Agricultural Research Service, Cheyenne, Wyoming.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1192-1197, November-
December 1975. 4 fig, 2 tab, 20 ref.
Descriptors: *Nitrates, *Fertilizers, *Soil profiles, *Soil-water movement, *Ion
transport, *Iowa, Analytical techniques, Inorganic compounds. Leaching, Nutrient
removal, Water pollution sources, Path of pollutants, Water quality. Nitrogen,
Soil analysis, Irrigation effects, Soil tests, Percolation, Groundwater, Root
zone, Agriculture, Loess, Contour farming. Corn(Field), Agricultural watersheds.
Nitrate movement within the 6.1-m soil profile of a watershed in southwestern
Iowa, fertilized at 448 kg N/ha per yr, resulted in a 720-kg/ha increase in
N03-N below the corn root zone during the 3-year study. The NO3-N concentration
of the baseflow from the watershed increased during this period, indicating that
some of the leached NO3-N reached the groundwater. The watershed fertilized at
the recommended N rate (168 kg/ha per yr) did not increase the quantity of N03-N
below the corn root zone; however, some NO3-N leaching did occur. Between April
1971 and April 1974, the accumulation of NO3-N in the profile of the excessively
fertilized watershed moved from the 1.0- to 3.1-m depth. The watershed fertilized
with 168 kg N/ha per yr did not show any zones of significant NO3-N accumulation
in the soil profile at any of the sampling dates. The depth to the water table on
the lowest contour sampled on the excessively fertilized watershed was 4.6 and
4.9 m in April 1973, and April 1974, respectively. The average N03-N concentration
for these two sampling dates at the water table depth increased from 3.7 to 12.9
ppm. The average NO3-N concentration at the water table depth on the normally
fertilized watershed was 2.0 and 4.5 ppm in April 1973 and April 1974, respectively,
with a water table depth of 3.0 m.
75:05B-042
INFILTRATION OF ORGANIC PHOSPHATE COMPOUNDS IN SOIL,
Rolston, D.E., Rauschkolb, R.S., Hoffman, D.L.
California University, Davis. Department of Land, Air, and Water Resources.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1089-1094, Novem-
ber-December 1975. 6 fig, 19 ref.
Descriptors: *Infiltration, *lrrigation practices, *Soil types, *Fertilizers,
*Phosphorus compounds, Leachate, Groundwater movement, Penetration, Soil properties,
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Phosphates, Nutrient removal, Phosphorus, Soil analysis, Evaluation, Soil chemistry,
Soil bacteria, Soil moisture, Soil water, Organic compounds, Clay loam.
Organicphosphate compounds may be moved greater distances into soil than is
possible with inorganic phosphates, inasmuch as organic phosphates must be enzyma-
tically hydrolyzed to orthophosphate before soil reactions inhibit movement. The
hydrolysis in solution and movement in soil of six organic phosphates were inves-
tigated in order to evaluate possible advantages of the compounds as fertilizers.
The compounds studied were glycerophosphate, methyl ester phosphate, glycol phos-
phate, ethyl ester phosphate, glucose 1-phosphate, and glucose 6-phosphate. The
infiltration of organic P compounds into Panoche clay loam soil and glycerophos-
phate into five soils differing in texture, clay type', organic matter, and pH and
into one soil at three water contents was investigated by infiltrating organic
P solution into columns of dry or moist soil at a rate of 66 kg of P/ha. Inorgan-
ic P concentration in bicarbonate extracts was measured as a function of soil
depth at the termination of infiltration. The movement of P from organic compounds
was compared with the movement of potassium phosphate. All the organic phosphates
hydrolyzed at similar rates. The P from all the organic compounds moved to
approximately the 12-cm depth in the calcareous Panoche clay loam soil with only
slight differences in P concentration above that depth, whereas inorganic phos-
phate moved no more than 2-3 cm. The enzymatic hydrolysis rate of glycerophosphate
and the resulting P distribution after infiltration was influenced by soil type.
75:05B-043
FLUOMETURON AND WATER CONTENT DISTRIBUTIONS DURING INFILTRATION: MEASURED AND
CALCULATED,
Wood, A.L., Davidson, J.M.
Oklahoma State University, Stillwater. Department of Agronomy.
Soil Science Society of America Proceedings, Vol. 39, No. 5, p 820-825, September-
October 1975. 7 fig, 1 tab, 20 ref.
Descriptors: *Path of pollutants, Pollutant identification, *Adsorption, Herbi-
cides, *Dispersion, *Infiltration, Laboratory tests, Numerical analysis, Soil
moisture.
Laboratory columns of Cobb sand were used to study the movement and distribution
of surface applied 1,l-dimethyl-3-(a,a,a,-trifluoro-m-tolyl) urea (fluometuron)
for three infiltration rates and two initial soil-water contents. Fluometuron
movement showed little dependence on initial soil-water content for a given infil-
tration rate. Experimental data indicated that equilibrium existed between the
adsorbed and solution phases for all infiltration rates and initial soil-water
contents studied with the exception of the ponded infiltration into airdry soil
case. A simultaneous numerical solution of the water and solute transport equa-
tion described a fluometuron pulse, for large infiltration rates, which lagged
the experimental data. The agreement between calculated and measured distributions
was improved when the infiltration rate was reduced. The shape of the fluometuron
pulse was reasonably well described by the mathematical model.
75:05B-044
NITROGEN MOVEMENT IN A SHALLOW AQUIFER SYSTEM OF THE NORTH CAROLINA COASTAL PLAIN,
Daniels, R.B., Gilliam, J.W., Gamble, E.E., Skaggs, R.W.
Soil Conservation Service, Raleigh, North Carolina.
Water Resources Bulletin, Vol. 11, No. 6, p 1121-1130, December 1975. 4 fig,
1 tab, 3 ref.
Descriptors: *Nitrogen, Movement, *Aquifers, *Coastal plains, Water pollution,
Waste water disposal, *North Carolina, *Path of pollutants, Aquicludes, Groundwater,
Porous media, Water table aquifers, Nitrates, Ammonium salts, Nitrites, Chemical
wastes, Water pollution sources. Flow, Migration, Waste disposal, Waste storage,
Industrial wastes, Groundwater movement.
Concentrations of ammonium- and nitrate-nitrogen of about 10,000 ppm moved from
an untreated surface storage pond into the groundwater in the sandy beds of the
surficial sediments in northeastern North Carolina. This high concentration of
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nitrogen moved through the permeable sandy beds with the groundwater above the
Yorktown Formation aquiclude to the Chowan River with only minor dispersion normal
to the hydraulic gradient. There was essentially no nitrogen movement into the
Yorktown aquiclude even though solutions of 2,000 ppm (soil basis) had been in
the overlying sediments for 2 to 3 years. The possibility of the nitrogen moving
into the deeper aquifers used for community water supplies is very small. Only
the shallow groundwater above the Yorktown Formation in the immediate area will
be contaminated with nitrogen because there is little lateral dispersion away
from the flow of groundwater toward the Chowan River.
75:058-045
COMPARISON OF THERMAL SCANNING AND IN SITU TECHNIQUES FOR MONITORING THERMAL
DISCHARGES,
Marmer, G.J., Tokar, J.V., Madding, R.P.
Argonne National Lab., Illinois.
Water Resources Bulletin, Vol. 11, No. 6, p 1157-1180, December 1975. 15 fig,
3 ref.
Descriptors: *Remote sensing, *Infrared radiation, *Thermal pollution, *Heated
water, *Path of pollutants, Nuclear powerplants, Great Lakes, *Lake Michigan,
*Isotherms, Aircraft, Temperature, Water cooling, Water pollution sources, Water
temperature, Lakes.
Two methods of measuring the behavior of thermal plumes were compared by applica-
tion to plumes at Point Beach Nuclear Power Plant on Lake Michigan. The classical
in situ method, which employs surface and subsurface thermistor probes extended
from a boat whose position is determined by a microwave ranging system, was
contrasted with a remote sensing technique which utilizes an aircraft-mounted
infrared scanner operating in the 8-14 micron range. Principal characteristics
of plume description were isothermal configurations, areas contained within iso-
therms, and centerline temperature decay. The in situ method was slow and subject
to effects of external forces over the test period, and it required interpolative
judgment to generate isotherms; but it did provide information on subsurface as
well as surface temperatures. Thermal scanning produced a considerably more de-
tailed picture of surface temperature but it was subject to distortion by surface
skin effects during extremely calm conditions. Good agreement between the methods
was found in four of five occasions; the fifth instance was a case of quiescent
conditions distorting the results of thermal scanning. It was proposed that the
methods be used jointly to achieve the best possible picture of thermal plume
behavior.
75:05B-046
SUSPENDED SEDIMENT AND TURBIDITY IN IRRIGATION RETURN FLOWS - A PROTOTYPE STUDY,
Hobson, S., Autry, B., McGuire, B.
Soil Conservation Service, Spokane, Washington.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 12 p, 2 fig.
Descriptors: *Suspended solids, *Suspended load. Sediment discharge, Sediment
load. Sediment yield. Turbidity, Surface irrigation.
Field measurements of inflow and outflows quantity and quality (suspended sedi-
ments and turbidity) were taken from five farm units. Canals, wasteways, and
sediment basins were similarly measured. The results provide prototype baseline
relationships of the effects of surface irrigation on these two parameters.
75:056-047
CHLORIDE CONTAMINATION IN ALUM CREEK, CENTRAL OHIO,
Pettyjohn, W.A.
Ohio State University, Columbus. Department of Geology and Mineralogy.
Ground Water, Vol. 13, No. 4, p 332-339, July-August 1975. 8 fig, 7 ref.
Descriptors: *Water pollution, *Chlorides, *Brines, *0hio, Brine disposal, Oil
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fields, Injection wells, Wastes, Pollutants, Surface waters, Groundwater, Water
pollution sources, *Path of pollutants, Seepage, Soil contamination, Water quality,
Taste, Discharge(Water), Sampling, Water analysis.
Periodically, Alum Creek at the Westerville water treatment plant contains exces-
sive concentrations of chloride, producing a salty taste. The chloride is not
removed during the water treatment process. Uncontaminated surface water and
groundwater throughout Alum Creek basin contain less than 25 mg/1 of chloride.
Larger concentrations are related to man's activity in the basin, particularly oil
production. The chloride content in samples of contaminated surface water ranged
from 26 to nearly 28,000 mg/1, while samples from oil-field brine pits ranged
between 3,000 and 57,000 mg/1. Even a brief examination of the data indicates
that most of the chloride contamination in Alum Creek is due to: (1) the discharge
of oil-field brines directly into the mainstem or its tributaries in the upper
reaches of the basin, or (2) the discharge of contaminated groundwater into streams.
In many areas, the highly mineralized groundwater that is now seeping into the
streams may have been contaminated a decade ago.
75:05B-048
ASSESSING UNRECORDED ORGANIC POLLUTION FROM AGRICULTURAL, URBAN, AND WOODED LANDS,
Yu, S.L., Whipple, W. Jr., Hunter, J.V.
Rutgers—The State University, New Brunswick, N.J.
Water Research, Vol. 9, No. 10, p 849-852, October 1975. 5 fig, 4 tab, 9 ref.
Descriptors: *Biochemical oxygen demand, *Water pollution, *Organic wastes,
*Water pollution sources, *Regression analysis, *New Jersey, Streamflow, Frequency
analysis, Watersheds(Basins), Runoff, Sampling, Analysis.
An investigation was conducted of the organic pollution for seven small New Jersey
watersheds representing agricultural, urban, and wooded lands. The 5-day biochem-
ical oxygen demand (BOD) was used as a main index of organic pollution. Data
obtained for 2.5 yr period indicated background BOD concentrations averaging from
0.5 to 2.0 mg/1 in all streams, except that a value of 9.0 mg/1 was obtained for
a residential-commercial-industrial area. During or after rainstorms, the BOD
loadings, in pounds per day per unit area, usually became more than ten times the
background amount for all streams. No significant correlation was found between
BOD concentration and flow rate, but good correlations were obtained between BOD
loadings and flows. The seasonal pattern of BOD loading distribution was examined.
The frequency distribution of BOD concentrations and loadings were also obtained.
75:05B-049
A SUMMARY OF THE BIOGEOCHEMISTRY OF NITROGEN COMPOUNDS IN GROUND WATER,
Behnke, J.
California State University, Chico.
Journal of Hydrology, Vol. 27, No. 1/2, p 155-167, October 1975. 4 fig, 1 tab,
55 ref.
Descriptors: *Nitrogen compounds, *Nitrates, *Water quality, *Groundwater, *Ni-
trogen cycle, *Biochemistry, Ammonia, Nitrites, Fertilizers, Inorganic compounds,
Nitrogen, Monitoring, Measurement, Data collections, Agricultural chemicals, Sur-
face runoff, Water chemistry, Water pollution, Path of pollutants, Water pollu-
tion sources.
The biogeochemistry of nitrogen compounds in groundwater is exceedingly complex.
The exclusive chemical monitoring of nitrates in groundwaters is overly simplistic
and may lead to errors in data interpretation. Nitrogen compounds are biodegrada-
ble, and an understanding of the physical, chemical, and biologic systems through
which transient water is moving is important in analyzing chemical data. Ground-
water nitrate contamination is generally encountered in shallow aquifers which
have direct or indirect hydraulic continuity with the ground surface. Surface
sources of groundwater nitrate contamination related to man's activities include
domestic sewage, agricultural practices, and high-density animal confinement.
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75:058-050
VERSATILE MULTIRANGE ANALYTICAL MANIFOLD FOR AUTOMATED ANALYSIS OF NITRATE-NITRO-
GEN,
Jackson, W.A., Frost, C.E., Hildreth, D.M.
United States Department of Agriculture, Agricultural Research Service, Watkins-
ville, GA 30677.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 592-593, May-June
1975. 2 fig, 1 tab, 9 ref.
Descriptors: *Nitrates, *Nitrogen, Nutrients, Laboratory equipment, Laboratory
tests, Soil chemistry.
This note describes a technique for extending up to 100 ppm the limits of deter-
mining nitrate-nitrogen in solution using a Technicon Autoanalyzer system. The
same modified analytical manifold can be used to determine three concentration
ranges of nitrate nitrogen 0^1, 0-10, and 0-100 ppm. To change concentration
range, change the sample entry point in the manifold and standardize the instru-
ment within the proper range.
75:058-051
SUBSURFACE BIOLOGICAL ACTIVITY IN RELATION TO GROUND-WATER POLLUTION,
McNabb, J.F., Dunlap, W.J.
Subsurface Environmental Branch, Robert S. Kerr Environmental Research Laboratory,
U.S. Environmental Protection Agency, P.O. Box 1198, Ada, Oklahoma 75820.
Ground Water, Vol. 13, No. 1, p 33-44, January-February 1975. 62 ref.
Biological activity occurring in subsurface regions below the soil zone may be of
considerable importance in determining the fate and effect of pollutants in ground
water, but this possibility has received little previous attention. This paper
comprises a discussion of subsurface biological activity in regard to ground-water
pollution as reflected by available literature references. The subsurface environ-
ment is discussed in terms of factors likely to be of greatest significance in
regard to the development of biological systems, and previous investigations of
subsurface microbial activity are reviewed. Available information indicates the
presence in the upper continental crust of the earth of numerous regions, particu-
larly those of sedimentary origin, which are probably suitable habitats for many
microbial species. Previous investigations of subsurface microbial activity clear-
ly show the presence of diverse microbial populations in many subsurface regions
below the soil zone. Hence, microbial activity appears both possible and probable
in most subsurface regions of importance in regard to ground water. Further
elucidation of the extent and nature of microbial activity in subsurface regions
is needed in developing methods for predicting the impact on ground-water quality
of pollutants released into the earth's crust.
75:05B-052
DEVELOPMENT OF FRESH GROUND WATER NEAR SALT WATER IN WEST VIRGINIA,
Wilmoth, B.M.
United States Environmental Protection Agency, 303 Methodist Building, Wheeling,
West Virginia 26003.
Ground Water, Vol. 13, No. 1, p 25-31, January-February 1975. 2 fig, 1 tab, 7 ref.
Descriptors: *Saline water, *Saline water intrusion, West Virginia, Groundwater,
Water quality, Water pollution.
Salt-water migration into relatively shallow rocks in the western half of West
Virginia is already rather far advanced. Because of the wide distribution of
salty ground water and connate brine at various depths, it is difficult to deter-
mine how much of the contamination is natural and how much is the result of sub-
surface industrial activities. Although some local salt-water problems are the
result of oil and gas operations, much of the regional near-surface salt water
is a natural condition unrelated to deep drilling or other industrial activities.
75:056-053
ON RADIOACTIVE WASTE MANAGEMENT: AN ANALYSIS OF THE PARAMETERS CONTROLLING
SUBSURFACE CONTAMINANT TRANSFER,
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Schwartz, F.W.
Department of Geology, Alberta University, Edmonton, Alta. (Canada).
Journal of Hydrology, Vol. 27, p 51-71, 1975. 9 fig, 12 equ, 15 ref.
Descriptors: *Radioactivity, *Radioactivity effects, *Model studies, Soil water
movement.
The problem of subsurface, radioactive-contaminant transfer is investigated
theoretically through the development of a two-dimensional model which considers
the simultaneous flow of water and mass. In addition to the well-known physical
transport processes, convection and dispersion, the model treats radioactive
decay and cation exchange which are two of the most important concentration atten-
uation processes. The influence of factors, which control the transport processes,
on subsurface contaminant distributions is demonstrated through the simulation
and analysis of a series of hypothetical cases. With respect to the physical
transport processes, hydraulic conductivity, porous medium dispersivity and the
location of the contaminant inflow zone are considered as controlling parameters.
75:058-054
NITRATE REDUCTION BY DENITRIFYING BACTERIA IN SINGLE AND TWO STAGE CONTINUOUS
FLOW REACTORS,
Dodd, D.J.R., Bone, D.H.
Department of Chemical Engineering, Queen's University, Kingston, Ontario, Canada.
Water Research, Vol. 9, No. 3, p 323, 328, March 1975. 6 fig, 1 tab, 5 equ, 18
ref.
Descriptors: *Denitrification, *Nitrate, *Bacteria, Chemical reactions.
Denitrification by a mixed bacterial population of medium was studied in batch, a
single stage continuous flow stirred reactor (CFSTR) and a two stage CFSTR at
30 degrees C. The optimum pH for denitrification, nitratase, nitrite reductase
activities and growth was found to be 7.5 in batch culture.
75:05B-055
NITRIFICATION IN RIVERS IN THE TRENT BASIN,
Curtis, E.J., Durrant, K., Barman, M.M.
Water Research Centre (Stevenage Laboratory), England.
Water Research Vol. 9, No. 3, p 255-268, March 1975. 4 fig, 3 equ, 13 tab, 15 ref.
Descriptors: *Nitrification, *Bacteria, Sediments, Chemical reactions.
The presence of autotrophic nitrifying bacteria in the waters and sediments of
both the River Trent and its polluted tributary the River Tame was established
and their concentrations determined. Nitrification was shown to occur mainly in
the sediments, where it was estimated that at least 80 per cent of the oxidation
of ammonia occurred.
75:05B-056
DENITRIFICATION WITH A BACTERIAL DISC UNIT,
Davies, T.R., and Pretorius, W.A.
National Institute for Water Research of the Council for Scientific and Industrial
Research, P.O. Box 395, Pretoria, South Africa.
Water Research, Vol. 9, No. 3, p 459-463, March 1975. 5 fig, 12 ref.
Descriptors: *Denitrification, *Bacteria, Anaerobic conditions, Anaerobic bacteria,
Chemical reactions.
An enclosed rotating disc unit was operated anaerobically as a denitrifying system,
with methanol as the hydrogen donor. The C:N ratio necessary for complete deni-
trif ication was found to be 2.6:1. Optimum pH for denitrification lay in the
range between pH 7.0 and -8.5. Q sub 10 values were 1.38 between 10 and 30 C,
-2.66 above 30 C and 13.06 below 10 C.
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75:05B-057
WATER POLLUTION FROM NONPOINT SOURCES,
McElroy, A.D., Chiu, S.Y., Nebgen, J.W., Aleti, A., Vandegrift, A.E.
Midwest Research Institute, Kansas City, Missouri 65110.
Water Research Vol. 9, No. 7, July 1975. p 675-681, 3 tab, 18 ref.
Descriptors: *Water quality, Water quality control, Return flow, Agriculture,
Mining.
The goals of water quality management have shifted profoundly in recent times
from protection of public health to several, and often conflicting, beneficial
uses of receiving waters. Resource protection has become an object of public
policy. It is essential that nonpoint as well as point sources of pollutants be
controlled to achieve current objectives of water quality management. The aim of
this study was to assess the nature and extent of nonpoint source pollution in
the United States from four major industrial activities: agriculture, silviculture,
mining, and construction.
75:058-058
NATURAL SOIL NITRATE: THE CAUSE OF THE NITRATE CONTAMINATION OF GROUND WATER IN
RUNNELS COUNTY, TEXAS,
Kreitler, C.W., Jones, D.C.
Bureau of Economic Geology, The Texas University, Austin, Texas 78712.
Ground Water, Vol. 13, No. 1, p 53-61, January-February, 1975. 11 fig, 1 tab,
13 ref.
Descriptors: *Nitrate, *Texas, Groundwater, Water quality, Water pollution, Soils,
Soil investigations.
The ground waters of Runnels County, Texas, are highly contaminated with nitrate.
The average nitrate concentration of 230 water samples was 250 mg/1 N03. The
natural variations of the stable nitrogen isotopes N14 and N15 identified natural
soil nitrate as the predominant source. Nitrate from animal wastes was of minor
importance. Dryland farming since 1900 has caused the oxidation of the organic
nitrogen in the soil to nitrate. Minimal fertilizer has been used because of the
lack of suitable water for irrigation. During the period 1900-1950, nitrate was
leached below the root zone but not to the water table. Extensive terracing after
the drought in the early 1950"s has raised the water table approximately 6 meters
and has leached the nitrate into the ground water. Tritium dates indicate that
the ground water is less than 20 years old.
75:05B-059
LOSSES OF DIURON, LINURON, FENAC, AND TRIFLURALIN IN SURFACE DRAINAGE WATER,
Willis, G.H., Rogers, R.L., Southwick, E.M.
United States Department of Agriculture, Southern Region, Louisiana Agriculture
Experiment Station, Baton Rouge , LA.
Journal of Environmental Quality, Vol. 4, No. 3, 1975. p 399-402, 5 tab, 27 ref.
Descriptors: *Return flow, *Runoff, *Herbicides, Water pollution. Water quality.
Pollution, Aquatic environment, Aquatic life, Drainage water.
Diuron, linuron, fenac, and trifluralin were applied to plots designed for sampling
surface runoff. Over a 3-year period, highest concentrations in runoff were
usually associated with rainstorms that occurred soon after application. Maximum
seasonal losses were less than 0.12, 0.30, 2.90, and 0.05% of the applied diuron,
linuron, fenac, and trifluralin, respectively. The data suggest that with proper
use on agricultural land in the lower Mississippi River Valley these herbicides
pose little threat to adjacent aquatic areas.
75:056-060
NITROGEN LOSSES FROM SOILS OF THE NORTH CAROLINA COASTAL PLAIN,
Gambrell, R.P., Gilliam, J.W., Weed, S.B.
North Carolina Agricultural Experimental Station, Raleigh, NC. North Carolina
University.
169
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Journal of Environmental Quality, Vol. 4, No. 3, 1975. p 317-323.
Descriptors: *Nitrogen, *Denitrification, *Nutrients, Soils, Soil investigations,
Drainage, Drainage effects, Fertilizers, Fertilization, North Carolina, Return
flow, Sediments, Corn.
Nitrogen balances were measured for a moderately well-drained and a poorly drained
soil in the North Carolina Coastal Plain to evaluate the effect of drainage on
the fate of unutilized fertilizer N. Approximately one-half of the fertilizer
N applied to each soil was not utilized by the crop. Most of the nitrogen lost
by surface runoff from both soils was organic nitrogen associated with the sediment.
However, there was a measurable increase in loss of nitrogen from fertilized plots
as compared to unfertilized plots. The poorly drained soil (27% organic matter)
had approximately 50% less surface runoff than did the moderately well-drained
soil (2% organci matter). However, the concentration of N in runoff from the
poorly drained soil was almost twice as great resulting in nearly identical N
losses from the two soils. Much of the total surface loss of N from corn occurred
during the first few months after planting.
75:05B-061
POLLUTION OF SURFACE IRRIGATION WATERS BY PLANT PATHOGENIC ORGANISMS,
Steadman, J.R., Maier, C.R., Schwartz, H.F., Kerr, E,D.
Nebraska University, Lincoln, Nebraska 68503.
Water Resources Bulletin, Vol. 11, No. 4, p 796-804, August 1975. 3 fig, 3 tab,
20 ref.
Descriptors: *Pollution, Water quality, Irrigation, Irrigaiton water, Surface
irrigation, Pathology, Return flow.
Systematic sampling of waterways and irrigation runoff from agricultural lands in
the North Platte Project of Nebraska in July and' August of 1972-1974 demonstrated
that phytopathogenic organisms were disseminated. The organisms monitored inclu-
ded the bean common blight bacterium, the bean white mold fungus and various nema-
todes. Although many types of nematodes often were recovered from irrigation
water, Heterodera sp. cysts which cause significant disease problems in the valley
were found infrequently. Patterns of movement of the bacterial and fungal organ-
isms were correlated with previous or current season infection of bean plants.
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Section XXII;
WATER QUALITY MANAGEMENT AND PROTECTION
EFFECTS OF POLLUTION (GROUP 05C)
75:05C-001
REGIONAL SEWERING AND GROUNDWATER QUALITY IN THE SOUTHERN SAN JOAQUIN VALLEY,
Schmidt, K.D.
Water Resources Bulletin, Vol. 11, No. 3, p 514-525, June 1975. 4 fig, 9 ref.
Descriptors: *Soil disposal fields, *Sewage effluents, *Sewage treatment,
*Sewage disposal, Groundwater, Groundwater movement.
Sewage effluent is commonly disposed of on land in arid regions, and the majority
usually recharges the groundwater. Few evaluations have been made of the effect
of effluent disposal on groundwater quality in the west. Groundwater hydrologists
are rarely involved with treatment plant design and operation or effluent disposal
in the San Joaquin Valley, California. The author's purpose is to evaluate the
effect of regional sewering programs on groundwater quality in this valley.
Research was conducted on past studies of sewage effluent disposal. An extensive
water sampling program was undertaken near the Fresno Sewage Treatment Plant.
Chloride contents were used to trace recharged effluent. The extent of recharged
effluent was delineated and traced for about ten miles. Sampling between the
plant and the urban Fresno area indicated a high probability of large-scale leak-
age of raw sewage into groundwater.
75:05C-002
A SIX-YEAR WATER, PHOSPHORUS, AND NITROGEN BUDGET FOR SHAGAWA LAKE, MINNESOTA,
Malueg, K.W., Larsen, D.P., Schults, D.W., Mercier, H.T.
United States Environmental Protection Agency, Corvallis.
Journal of Environmental Quality, Vol. 4, No. 2, p 236-242, April-June 1975.
11 fig, 5 tab, 11 ref.
Descriptors: *Phosphorus, *Nitrogen, *Water pollution, *Water pollution effects,
Eutrophication, Hydrologic budget, Nutrients, Waste water, Minnesota.
Water, phosphorus, and nitrogen budgets of eutrophic Shagawa Lake, Minnesota
were determined from 1967-1972 to assist in defining the significance of the
loading from the city of Ely secondary waste water treatment plant to the trophic
state of the lake. Ely's municipal waste water accounted for about 80% of the
P, 24% of the N, and only 2% of the water to Shagawa Lake while the major tribu-
tary, Burntside River, accounted for 66% of the water, 42% of the N, and only 11%
of the P to the lake. An average of 30% of the P was retained within the lake.
The water and nutrient budgets, along with field and laboratory studies, indica-
ted that high levels of P from the municipal waste water treatment plant were
mainly responsible for the eutrophic condition of Shagawa Lake.
75:05C-003
THE RESPONSES OF SOILS AND SOIL MICROORGANISMS TO SILVER IODIDE WEATHER MODIFICA-
TION AGENTS,
Sokol, R.A., Klein, D.A.
Colorado State University, Fort Collins, Department of Microbiology.
Journal of Environmental Quality, Vol. 4, No. 2, p 211-214, April-June, 1975.
4 fig, 18 ref.
Descriptors: *Soil chemistry, *Soil microorganisms, *Cloud seeding, *Organic
matter, *Silver iodide, Microbial degradation, Soil environment.
To determine the consequences of Agl weather modification agent accumulation to
the soil microbial environment, the effects of added silver compounds to micro-
bial growth, anaerobic cellulose degradation, and the soil environment adjacent
to a cloud seeding generator were investigated. Silver ion inhibited microbial
growth in culturals at low concentrations and cultures saturated with Agl displayed
171
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an inhibition of growth initiation. An analysis of the soil surrounding a seed-
ing generator site in Steamboat Springs, Colorado indicated that deposited silver
tends to remain near the soil surface. Alterations in the soil environment due
to high silver concentrations were indicated by .consistently higher organie matter
levels, water contents, microbial populations and rates of soil respiration.
These results suggest that high concentrations of seeding agent potentially can
alter the soil microbial environment by inhibiting organic matter decomposition,
but that the silver levels which accumulate in seeded target areas should have
no overt effects on the soil environment.
75:050-004
EUTROPHICATION OF MICROPONDS,
Batchelder, A.R.
United States Department of Agriculture, Western Region Agricultural Research
Service and Colorado Agricultural Experimental Station.
Journal of Environmental Quality, Vol. 4, No. 4, p 520-526, October-December 1975.
3 fig, 6 tab, 14 ref.
Descriptors: *Eutrophication, *Algae, *Nutrients, Water quality, Soil investiga-
tions.
Three soils having different chemical and physical properties were flooded with
deionized water and used as bottom soils for greenhouse microponds. The submerged
soils supplied sufficient nutrients to the overlying water to sustain algal growth
for 489 days in two successive floodings of 219 and 270 days each. Differences
in electrical conductivity, pH, and nutrient concentration were observed among
the three soils and a control nutrient solution. During the first flooding, in-
digenous algae prevailed in the soil systems, but during the second flooding the
dominant algal genera were less diversified.
75:05C-005
SOLUBLE SALTS AND NITRATE DISTRIBUTION IN IRRIGATED LETTUCE BEDS,
Hummadi, K.B., Fangmeir, D.D., Tucker, T.C.
Arizona University, Tucson, Department of Soils,
Transactions-of the American Society of Agricultural Engineers, Vol. 18, No. 4,
p 686-689, July-August 1975. 6 fig, 2 tab, 9 ref.
Descriptors: *Irrigation, *Irrigation effects, *Salinity, *Saline soils,
*Lettuce, Nitrate, Sprinkler irrigation, Furrow irrigation, Irrigation practices.
The salt and nitrate content was measured in lettuce beds irrigated by sprinkler,
furrow between beds. Furrow irrigation continually increased the salt content
of the surface 2.5 cm of soil in the bed particularly in the center of the bed.
Sprinkler irrigation slightly decreased the salt content during the season. Be-
low 7.5 cm the irrigation method had little effect.
75:05C-006
INTERACTION BETWEEN AQUATIC PLANTS AND BED SEDIMENTS IN MERCURY UPTAKE FROM FLOW-
ING WATER,
Mortimer, D.C., Kudo, A.
Ottawa River Project, Joint study by National Research Council of Canada Labora-
tories and Ottawa University.
The Journal of Environmental Quality, Vol. 4, No. 4, p 491-495, October-December
1975. 6 fiq, 4 tab, 8 ref.
Descriptors: *Mercury, *Aquatic environment, *Aquatic life, *Aquatic plants,
Aquatic soils.
Bed sediment from a known zone in the Ottawa River study area and cuttings of Elo-
dea densa were set out in aquaria in a 24-day controlled, flowing water experiment.
Elodea was planted in sediment and in glass beads, and sediment was exposed with
and without plants, all in the same aquaria for 7 days before the addition of
mercuric chloride were continuously metered into the input water to yield aquar-
ium levels of 0.2,2, and 10 micro-g/liter. There was no signigicant difference
in the uptake rate between the two forms of mercury. Uptake was proportional
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to water concentration over the entire 17-day exposure period in both plants and
sediment. Methyl mercury was more toxic to plant growth in this time interval
than inorganic mercury.
75:050007
INVESTIGATION AND REHABILITATION OF A BRINE-CONTAMINATED AQUIFER,
Fryberger, J.S.
Engineering Enterprises, Inc., P.O. Box E, Norman, Oklahoma 73069.
Ground Water, Vol. 13, No. 2, p 155-160, March-April 1975. 4 fig, 1 tab, 7 ref.
Descriptors: *Aquifers, *Groundwater, *Brine disposal, Arkansas, Water quality,
Pollution, Water pollution.
Faulty disposal of oil field brine through an "evaporation" pit and later through
a faulty disposal well resulted in the contamination of one square mile of an
alluvial aquifer in southwestern Arkansas. The physical parameters of the conta-
mination are defined, and some of the chemical changes that occur as the brine
moves through the aquifer are explained. In addition, alternate methods of aqui-
fer rehabilitation are explored, and the costs of rehabilitation are compared
with potential benefits. It is concluded that rehabilitation is not now econo-
mically justified,
75:05C-008
COMBINED EFFECTS OF LOW OXYGEN AND SALINITY ON GERMINATION OF A SEMI-DWARF
MEXICAN WHEAT,
Aceves-N., E., Stolzy, L.H., Mehuys, G.R.
Colegio de Postgraduados, Excuela Nacional de Agricultura, Chapingo, Mexico.
Agronomy Journal, Vol. 67, No. 4, p 530-532, July-August 1975. 4 fig, 1 tab,
7 ref.
Descriptors: *Oxygen, *Oxygen requirements, *Wheat, Crop response, Salinity,
Soil salinity, Germination, Seeds.
The simultaneous occurrence of low oxygen and high salinity conditions is common
in a wide range of irrigated soils. The combined effects of 02 and osmotic poten-
tial stresses on germination of wheat were tested under growth chamber conditions.
A range of 02 concentrations and salinity levels were chosen to simulate soil
aeration and salinity combinations that might be expected to occur in well-aerated,
fine-textured, saline, and saline-sodic soils. Daily observations of number of
seeds germinated and days to first germination were recorded.
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Section XXIII
WATER QUALITY MANAGEMENT AND PROTECTION
WASTE TREATMENT PROCESSES (GROUP 05D)
75:050-001
BIOLOGICAL DENITRIFICATION AND ITS' APPLICATION IN TREATMENT OF HIGH-NITRATE
WASTE WATER,
Francis, C.W., Callahan, M.W.
Oak Ridge National Laboratory, Oak Ridge, TN
Journal of Environmental Quality, Vol. 4 No. 2, p 153-163, April-June 1975.
2 fig, 1 tab, 82 ref.
Descriptors: *Nitrate, *Nitrite, *Nitrogen, *Waste water, *Waste water treatment,
*Denitrification, Waste water disposal, Fertilizers.
One method of removing nitrate nitrogen from waste water effluents appears to
be biological denitrification. Considerable research regarding denitrification
of municipal and agricultural waste water containing relatively low concentrations
of nitrate has been conducted. However, very little research has been carried
out on the feasibility of applying the process to waste water effluents which
contain in excess of 1,000 ppm NO(3)-N. Waste water effluents containing this
magnitude of nitrates are generated in fertilizer and explosive manufacturing
operations. Large quantities of nitrates are also expected to be produced at
future nuclear fuel processing and uranium oxide fuel fabrication plants. This
review comprehensively evaluates the various requirements for biological denitri-
fication in respect to NO(3)-N concentrations as well as quantity and type of
carbon substrate and complementary cations. It also assesses which engineering
design, e.g., modified activated sludge units, packed-bed reactors, or anaerobic
columns, may be most applicable in biological denitrification of waste streams
containing concentrations greater than 1,000 ppm NO(3)-N.
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Section XXIV
WATER QUALITY MANAGEMENT AND PROTECTION
ULTIMATE DISPOSAL OF WASTES (GROUP 05E)
75:05E-001
OUTLOOKS FOR THE FUTURE OF DEEP WELL DISPOSAL,
Conrad, E.T., Hipson, N.E.
Water Resources Bulletin, Vol. 11, No. 2, p 370-378, April 1975. 1 fig, 4 tab,
6 ref.
Descriptors: *Wells, *Waste disposal, *Waste disposal wells, Wastes, Groundwater.
This paper presents a rationale for estimating the quantities of industrial
waste that may be disposed of by deep well injection. For the purpose of this
discussion, deep well injection refers to disposal to a saline aquifer (not a
potable water supply) and does not include injection of oil field brine. Litera-
ture discussing regulation and curtailment of deep well injection of industrial
wastes presents the argument that little is known about this method, which is true
to an extent. Industrial wastes have been disposed of by deep well injection for
which only 162 are currently operating. However, related experience has been
deep wells now being utilized for this purpose.
75:05E-002
DO HEAVY METALS PREVENT THE AGRICULTURAL USE OF MUNICIPAL SLUDGE,
Jorgensen, S.E.
Royal Danish School of Pharmacy, Copenhagen.
Water Research, Vol. 9, p 163-170, 1975. 13 fig, 5 tab, 16 ref.
Descriptors: *Heavy metals, *Agriculture, *Sludge disposal, Groundwater, *Soil
disposal fields, Soil treatment, Soil-water-plant relationships, Humus.
The chemical binding of heavy metals on different samples of soil was found. The
pollution of heavy metals in soils by use of sewage sludge can be controlled by
maintaining the pH at 7.0 or more and applying sludge preferably on soil with a
high content of humus and clay. More than 200 tons of municipal sewage sludge can
be applied per acre total, e.g. 20 tons per year over a 10 year period, without
any danger. In most cases, lead is the metal limiting the amount of sludge that
can be used due to its possible contamination of ground water.
75:05E-003
EFFLUENT FOR IRRIGATION - A NEED FOR CAUTION?,
Walker, W.H.
Illinois State Water Survey, Urbana, Illinois 61801.
Ground Water, Vol. 13, No. 1, p 11-15, January-February 1975. 24 ref.
Descriptors: *Water quality, *Water quality control, Water pollution, Return
flow, Irrigation, Irrigation practices. Sewage, Sewage effluents, Sewage treat-
ment.
Existing pollution protection laws prohibit surface-water dilution of effluents
and sludges. Drying, burning, or distilling them is very costly, causes air
pollution, and produces potentially hazardous chemical residues which still must
be disposed of in some nonpolluting fashion. There are no "technologically feas-
ible, economically reasonable" alternative methods of effectively treating these
wastes to an acceptable quality level for discharge to streams. For these reasons,
land disposal of sewage effluent and sludges now is being widely promoted and em-
ployed as the best available method of treatment. Most operating facilities for
land disposal of effluents are not monitored adequately to provide required data
to quantitatively evaluate the total buildup and possible subsequent release of
toxic chemicals in contiguous soil, plant, and water environments. Considering
the potential danger to public health which may result if widespread use of this
particular waste disposal practice is employed, it is imperative that all such
permitted sites be monitored and evaluated in detail for all possible adverse
effects, and the results of these findings then considered in the design and oper-
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ation of future installations, if minimal pollution from this practice is to be
assured in the future. Concurrent with this work, research must be expedited and
greatly expanded to develop effective alternative treatment methods to employ
where land disposal of effluent proves to be impracticable.
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Section XXV
WATER QUALITY MANAGEMENT AND PROTECTION
WATER TREATMENT AND DISTRIBUTION (GROUP 05G)
75:05F-001
PRECIPITATION OF PHOSPHATE FROM SOLUTION USING ALUMINUM SALT,
Hsu, P.H.
Cook College, Rutgers University, The State University of New Jersey, New Bruns-
wick, New Jersey 08903. Department of Soils and Crops.
Water Research, Vol. 9, No. 12, p 1155-1161, December 1975. 8 fig, 5 tab, 1 egu,
18 ref.
Descriptors: *Phosphate, *Chemical precipitation, Water guality, Waste water,
Waste water treatment.
In the absence of any interfering component, the optimum pH range and the effec-
tiveness of aluminum phosphate precipetation were found to vary with the initial
ratio of phosphate to aluminum in sample preparation. Phosphate was almost com-
pletely removed from solution when aluminum was in large excess. At maximum,
1 mole of phosphate was precipitated by 1 mole of aluminum, but this occurred
only when phosphate was in large excess.
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Section XXVI
WATER QUALITY MANAGEMENT AND PROTECTION
WATER QUALITY CONTROL (GROUP 05G)
75:05G-001
OBJECTIVES OF WATER QUALITY PLANNING,
Krause, K.S.
Kansas Water Resources Board, Topeka.
Journal of the Hydraulics Division, Proceedings of American Society of Civil
Engineers, Vol. 101, No. HY3, Paper No. 11200, p 471-476, March 1975.
Descriptors: *Warer resources, *Planning, *Water quality control, Hydraulics,
Decision making, Land use, Natural resources, Conservation, Irrigation, Educa-
tion, Public health, Environment.
Planning is a useless effort if it does not produce a viable procedure for
reaching its objectives. Our political process is presently atuned to crisis
reaction, producting short-range decisions and simplistic solutions to problems
which often serve to confuse and delay the adoptions of hard viable solutions.
The control of water quality is noble objective in itself; however, the need
for it is symptomatic of a much deeper and profound disease that must be cured
or prevented before a completely successful water quality control program can
be achieved. The disease is that of 'living beyond our resource means'. To
overcome this, the nation objectives should be to: (1) minimize natural resource
waste; (2) protect the public health and ecosystem; (3) provide for a system of
control that has a practical probability of being achieved; and (4) provide
for a positive decision-making process that leads to the rapid consumation of
the objectives previously stated.
75:05G-002
GROUND-WATER'S ROLE IN WATER QUALITY MANAGEMENT,
Osgood, J.O.
Pennsylvania Department of Environmental Resources, Harrisburg. Bureau of Water
Quality Management.
Journal of the Hydraulics Division, Proceedings of the American Society of
Agricultural Engineers, Vol. 101, No. HY3, P 517-521, March 1975.
Descriptors: *Groundwater, *Water quality contol. State jurisdiction, Water
management (Applied), Surface waters. Water pollution, Hydrogeology, *Pennsyl-
vania, Administration, Water quality standards.
Federal legislation requires each state to protect the quality of its surface
waters, yet this protection is stated only indirectly for subsurface waters.
Because surface waters/groundwater evaluation must be integrated in water quality
monitoring, the state of Pennsylvania was one of the first to design a
Comprehensive Water Quality Management Plan (COWAMP) to protect groundwater as
a vital resource. Over two-thirds of that state's public water supply and 99%
of its private water supplies are dependent upon groundwater. The slow migra-
tion of contaminated surface water has been demonstrated to cause groundwater
pollution. Examples of this are landfill leachate, leaking industrial water
impoundments, gasoline spills flushed to the soil, improperly developed spray
irrigation sites, and urban runoff infiltration. The COWAMP plan considers
groundwater in its role as a major water supply, including new developments in
well construction. Groundwater is also seen as a transporting medium for
contaminant dispersion; for example gasoline spills move on top of the water
table and fumes may migrate up through the soil into buildings as it flows.
Additionally, activities affecting the recharge/discharge balance influence
waste water treatment and related costs. COWAMP hopes to identify existing
hydrogeological characteristics, to study man's impact on existing resources,
and to evaluate alternatives. This involves considering areas of poor water
quality, areas requiring special protection, such as recharge zones, important
watersheds; large population centers, and areas where major population growth
is predicted.
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75:050-003
SALINITY CONTROL AND FEDERAL WATER QUALITY ACT,
Bessler, M.B., Maletic, J.T.
Bureau of Reclamation, Denver, Colorado. Water Quality Office.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol. 101,
No. HY5, Proceeding paper No. 11321, p 581-594, May 1975. 6 fig, 1 tab, 17 ref.
Descriptors: *Salinity, *Water quality control, *Colorado River, *Water manage-
ment (Applied), Water resources development, Comprehensive planning, Standards,
Economic impact, Evaluation, River basins, Simulation analysis, Computer models,
Constraints, Mathematical models, Systems analysis, Federal jurisdiction, South-
west U.S.
Salinity as a mineral pollutatnt is receiving increased attention in the Western
U.S. in terms of economic impacts. The salinity control problem on the Colorado
River is examined in relation to the Federal Water Quality Act, PL 92-500.
Even basin-wide slainity controls as presently envisioned will not be able to
meet anticipated salinity standards and the 'zero discharge1 goals of the Act.
Described is the Colorado River Water Quality Improvement Program (CRWQIP),
only one element of an entire matrix of management plans in the Colorado River
Basin. CRWQIP has five categories of control under present study: river system
management; point source control; diffuse source control; irrigation source
control; and return flow utilization. Options that may be required for the pre-
sent nondegradation policy are: minimize deep percolation losses from irrigation;
desalt return flow and divert brine stream from the system; desalt water prior
to select use; divert and reuse saline flows for nonagricultural use; and
combinations of foregoing. Discussed is the use of the Colorado River Simulation
Model. A new planning strategy of total water management is suggested to identi-
fy and evaluate water needs, water resources, physical technology, management
technology, and other nonphysical constraints. Thus, specific economic limita-
tions and institutional constraints identified under the various management op-
tions will assist in setting attainable salinity levels within a river basin in
lieu of meeting rigid zero discharge limitations for each user. Systems analysis
tools are advocated for comprehensive basinwide management.
75:05G-004
HYDROGEOLOGY AND WATER QUALITY MANAGEMENT,
Landon, R.A.
Moody and Associates, Incorporated, Harrisburg, Pennsylvania. Environmental
Services Division.
Journal of the Hydraulics Division, American Society of Civil Engineers, Vol.
101, No. HY2, Proceedings paper 11137, p 285-289, February 1975.
Descriptors: *Management, *Hydrogeology, *Water quality, Aquifer management,
Environmental effects, Land use, Topography, Soils, Geology, Geochemistry,
Surface-groundwater relationships, Groundwater movement, Discharge (Water),
Model studies, Methodology, Geologic mapping, Maps, *Pennsylvania, Hydraulics.
Numerous environmental and water quality investigations were completed which
are largely two-dimensional in that the environmental and land-use factors were
evaluated from a surficial standpoint only, with minimum concern given to the
third dimension of depth, and therefore, the majority of the hydrogeologic
framework lying below land surface. An integral part of Comprehensive Water
Quality Management Planning (COWAMP) program for Pennsylvania is a definition of
the hydrogeologic framework that controls the occurrence of ground water,
as well as data describing the quantity and quality of that resource. Recogni-
tion of the fact that the environment is a complex interweaving of many variables,
and the strong control exerted by the natural physical components comprising the
hydrogeologic framework can be expected to minimize or avoid the deleterious
and sometimes catastrophic results of the omission of such recognition.
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75:050-005
LEGAL PERSPECTIVE ON WATER QUALITY MANAGEMENT,
Blazey, D.R. . _a
Department of Environmental Resources, Commonwealth of Pennsylvania, Harrisburg, PA
Journal of the Hydraulics Division, Vol. 101, No. HY5, p 595-601, May 1975. 12 ret.
Descriptors: *Legal aspects, *Water quality control, Water quality, Water
quality standards, Water resources development, Pennsylvania.
It has become increasingly obvious that wastewater treatment requirements and
water supply are critical determinates of growth patterns. If we run a costly
interceptor through prime farm land, it is likely that urbanization of one sort
or another will follow. If stream discharge standards are set sufficiently high
to protect the fragile ecosystems of first and second-order streams, development
in those watersheds will be discouraged. If we make water allocations based upon
an uncritical acceptance of growth projections we may not only jeopardize inter-
related water quality objections but may also irreparably upset stable environmen-
tal relationships in the donor or recipient area. Water quality planning should
not just be sewer planning for narrow public health and water quality goals,
it should analyze all the complex elements of our dependence upon water and should
recommend a management system consistent with the long-term survival of human
life and the natural surroundings which we cherish.
75:05G-006
WATER RIGHTS AND WATER QUALITY MANAGEMENT,
Walker, W.R., Cox, W.E.
Virginia Water Resources Research Center, Blacksburg, VA.
Journal of the Hydraulics Division, Vol. 101, No. HY3, p 511-516, March 1975.
17 ref.
Descriptors: *Water rights, *Water quality control, *Institutional constraints,
Institutions.
It appears that the basic institutional weaknesses of water rights make them
unsuitable as a primary water quality management device. The comparative advan-
tages of the administrative agency approach are such that few would seriously
question its desirability. Yet water rights still function in an important sup-
plemental capacity. Although there are substantial obstacles to successful legal
action in connection with the violation of such rights, successful suits are
brought and the deterrent effect with regard to other polluters serves to assist
administrative efforts. Also of continuing importance is the function of judi-
cially enforced water rights in relieving inequities between individual parties.
Even if a management program achieves water quality goals such that the general
public interest is being served, it is possible that localized problems still
could exist. The courts are the ideal institution in this situation for applying
the principles of private rights and distributing the losses resulting from water
quality alteration between the parties involved in accordance with some concept
of social justice.
75:05G-007
A NOTE ON COST-EFFECTIVENESS IN DATA ACQUISITION IN WATER QUALITY MANAGEMENT,
Nielsen, K.S., Friborg, N., and Bundgaard-Nielsen, M.
Vandkvalitetsinstitut, Soborg(Denmark).
Water Resources Research, Vol. 11, No. 2, p 357-358, April 1975. 2 fig, 1 ref.
Descriptors: *Water quality, *Management, *Sarapling, *Costs, Equations, Effluents,
Monitoring, River basins, Optimization, Constraints, Algorithms, Systems analysis,
Mathematical models.
An iterative procedure for sampling in water quality management is presented.
The procedure, which utilizes constrainted mixed integer programming, establishes
a relationship between cost of sampling and relative uncertainty in total dis-
charge into the water sytem and at the same time provides an optimal frequency
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matrix for sampling. The frequency of sampling at each discharge is treated as
an independent variable.
75:05G-008
MODELS OF LAND AND WATER ALLOCATION TO IMPROVE ENVIRONMENT AND WATER QUALITY
THROUGH SOIL LOSS CONTROLS,
Heady, E.O., Nicol, K.J.
Iowa State University, Ames. Center for Agricultural and Rural Development; and
Iowa State University, Ames. Department of Economics.
Water Resources Research, Vol. 11, No. 6, p 795-800, December 1975. 4 fig, 5 tab,
4 egu, 3 ref.
Descriptors: *Water quality control, *Environment, *Water allocation (.Policy) ,
Land resources, Agriculture, United States, Water supply, Crops, Livestock, Tech-
nology, Evaluation, Economic impact, Optimization, Constraints, Equations, Mathe-
matical models, Systems analysis.
A soil loss, land-water allocation optimization model has been developed that is
applicable to all agricultural land in the United States. The model includes
223 producing areas, 1891 land resource areas, and 51 water supply regions. Dif-
ferent cropping systems and technologies are defined for each crop and livestock
system in each of the 1891 land resource regions. The programming model is thus
of very large scale, including also a transportation submodel and market regions.
As a means of water quality improvement, limits are placed in the per acre per
year soil loss as a means of reducing sedimentation and the transport of nitrogen
and phosphates into streams. A nitrogen balance equation limits fertilizer pur-
chases and forces utilization of livestock wastes in the region. The model forces
a land use system and set of technologies over the country and interregionally
having soil loss unrestricted, at 10 tons per acre, at 5 tons per acre, and at 3
tons per acre. The unrestricted and 5-ton limits are reviewed in this paper in
relation to impacts on soil loss (reduced about 25%), crop distribution, technology,
water use, and farm prices.
75:05G-009
RECLAMATION OF SOILS CONTAMINATED WITH RADIOACTIVE STRONTIUM,
Lagerwerff, J.V., Kemper, W.D.
Agricultural Research Service, Beltsville, Maryland.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1077-1080, November-
December 1975. 3 fig, 3 tab, 13 ref.
Descriptors: *Land reclamation, *Strontium radioisotopes, *Leaching, *Radioacti-
vity, *Soil contamination, Reclamation, Fallout, Radiochemical analysis, Environ-
mental effects, Leachate, Radioactivity techniques, Chemical analysis, Analytical
techniques, Soil management, Gypsum , Dispersion, Tracking techniques, Pollutants,
Pollution abatement, Colorado, Soil treatment.
Evesboro loamy sand, Sassafras sandy loam, and Fort Collins silt loam were treated
with a mixed Ca-Sr solution to give about 95% saturation with Ca and 5% saturation
with Sr. Samples of these soils were place in acrylic cylinders and leached with
0.06N CaC12 to remove Sr. The leachings were mechanically controlled at various
rates for different periods of time. Extracting the leached soil samples with IN
HC1 yielded residual Sr equal to 0.43, 0.47, and 0% of the Sr exchange capacity
of the Evesboro, Sassafras, and Fort Collins soils, respectively. There was gen-
eral agreement between Sr concentrations measured at various depths and those
calculated on the basis of the Lapidus-Amundson equation, especially so with hea-
vier soils. The Evesboro and Fort Collins soils were also tagged with carrier-
free Sr85 and, mounted in columns, leached with 0.06N solutions of either CaC12
or SrC12. The removal of Sr85 was more complete from the Evesboro than from the
Fort Collins soil, and from the center than from the edge of the columns. Short-
term leaching capability of SrC12 .exceeded that of CaC12 where Sr85 was present in
amounts small enough to be adsorbed mostly on specific soil adsorption sites.
Where larger amounts .of Sr85 had been adsorbed, Ca was equally effective as Sr in
replacing the contaminant.
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75:050-010
SALINITY POLICY FOR COLORADO RIVER BASIN,
Skogerboe, G.V., Walker, W.R.
Colorado State University, Fort Collins. Department of Agricultural Engineering.
Journal of Civil Engineers, Vol. 101, No. HY8, p 1067-1075, August, 1975. 1 fig,
13 ref.
Descriptors: *Salinity, *Colorado River, *Water policy, *Water quality control,
*Water law, Water pollution, Saline water, Salts, Irrigation water, Desalination,
Colorado River Basin, Colorado River Compact, Mexican Water Treaty, Water resources,
Mexico, Water supply, Impaired water quality, Costs, Arizona, California, Water
management(Applied).
Increasing salinity concentrations in the Colorado River are threatening the
utility of water resources in the downstream areas of Arizona, California, and
the Republic of Mexico. The U.S. Environmental Protection Agency reports that
existing damages to lower basin users would increase from $16,000,000 annually
in 1970 to $51,000,000 annually by the turn of the century if planned developments
do not include appropriate salinity control measure. A brief description of the
most important salinity control measures is given along with a short summary of
the Colorado River Compact, the Upper Colorado River Compact, and the Mexican
Water Treaty. The water quality goal for the Colorado River to maintaining salin-
ity concentrations in the lower stem at or below present levels would be better
than setting numerical standards. This policy should be applied to each state
by offsetting salinity detriments resulting from each new development with salinity
control measures that will maintain a net .salt balance leaving state boundaries.
75:050-011
GEOCHEMICAL FACTORS AFFECTING ARTIFICIAL GROUNDWATER RECHARGE IN THE UNSATURATED
ZONE,
Wood, W.W., Signor, D.C.
Geological Survey, Lubbock, Texas.
Transactions of the ASAE, Vol. 18, No. 4, p 677-683, July-August 1975. 11 fig,
1 tab, 14 ref.
Descriptors: *Geochemistry, *Artificial recharge, *Groundwater, *Chemcontrol,
Chemical analysis, Recharge, Texas, New Mexico, Ion exchange, Anion exchange,
Cation exchange, Hydrogen ion concentration, Adsorption, Hydrology.
Recent research on artificial groundwater recharge has focused on spatial-temporal
aspects. The type and magnitude of chemical controls at a site are studied.
Chemical considerations are placed into two categories: the change in geometry
of the interstitial pore space and the prediction of the quality of the water with
time. The observations discussed fall into the second category. The recharge
facility used, a 9.4-ha basin near Lubbock, Texas, is typical of the Southern High
Plains of Texas and New Mexico, and the water was imported from Lake Meredith,
near Amarillo. Porous ceramic cups were used to collect water samples at depths
of 0.6, 2, 8, 16, 23, and 33 meters, first daily and then weekly. Chemical
analyses were performed for pH, bicarbonate and specific conductance. Chloride
concentration increased with depth. Ion exchange was one of the most important
chemical processes observed in the system. Cation and anion exchange took place,
but cation exchange dominated. This could be an important consideration in a
predictive model, depending on whether or not the water is intended for human
consumption. Some sulfate adsorption takes place and the effects are still being
studied. Desorption of silica was the other major mechanism that affected the
water quality. Sulfate reduction signaled a hydrologic change but the effect was
small because of the rapid loss of hydraulic conductivity. Some mineral solution
occurred but also had a very small effect. Studies should be conducted at
other sites on the Southern High Plains of Texas and New Mexico, including more
detailed analyses. With enough pertinent data incorporated into a model, accurate
predictions can be made on water quality changes.
75:05G-012
VARIATION OF SUSPENDED SEDIMENT LOAD IN THE PALOUSE REGION OF THE NORTHWEST -
182
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McCool, O.K., Papendick, R.I.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 20 p, 4 fig, 9 tab, 11 ref.
Descriptors: *Suspended load, *Suspended solids, *Sediment yield, *Sediment
load, *Sampling, Water quality, Return flow, Water quality control, Water pollu-
tion.
Sediment concentrations in the Palouse small-grain dryland region of the North-
west are extremely variable on a daily, seasonal, and annual basis. Runoff
events of from one to a few days in length can account for large percentages of
the annual sediment discharge, and the sediment transport of a given year can be
as large as the total of 4 or 5 other years. Sampling programs based on weekly
samples, even at stations with excellent streamflow records, can give extremely
misleading results. Sampling programs of 1 or 2 years' duration can also give
extremely misleading results. If money and personnel constraints dictate a low-
frequency short-duration sampling program, then it is essential that some typical
portion of the study area be monitored with a high-frequency longer-duration
sampling program to assess the results and for adjustment purposes.
75:05G-013
WATER QUALITY CONTROL THROUGH SINGLE CROP AGRICULTURAL, NO. 4,
Lundberg, K.R., Trihey, P.T.
Bemidji State College, Minnesota. Center for Environmental Studies.
Available from the National Technical Information Service, Springfield, Va 22161.
Environmental Protection Agency, Report EPA-660/2-75-026, June 1975. 116 p, 6 fig,
24 tab, 27 ref, 2 append.
Descriptors: *Farm wastes. Nitrogen, Peak, Rice, Nutrients, Phosphorus, Water
quality control, Surface waters, Crops response, Consumptive use, Bioassay,
Minnesota, Agriculture.
A study was conducted to determine effects on water quality from flooded paddies
used for the commercial culture of wild rice, Zizania aquatica. Water samples
were taken from flooded impoundments of fertilized peat and mineral soils as well
as unfertilized peat soils. Weekly changes in the chemical and physical parame-
ters of water entering, within, and discharged from paddies were measured through
the summer. No significant changes were observed in the receiving water until
fall draindown occurred when increases in dissolved solids, total Kjeldahl-nitro-
gen and total phosphorus occurred in the Clearwater River. Algal assay tests
indicated that the increase in nutrients released from rice paddies were not sig-
nificantly greater than would be expected in normal runoff in the area and much
less than the amounts released from most agricultural endeavors. Consumptive
water use was 20-22 inches per acre (51-56 cm/ha).
75:056-014
AN ECONOMIC INVESTIGATION OF TAX POLICIES FOR CONTROLLING EFFLUENT DISCHARGE,
Sassone, P.G., Ferrar, T.A.
Georgia Institute of Technology, Atlanta. Industrial Management.
Journal of Environmental Management, Vol. 3, p 43-57, 1975. 4 fig, 15 ref.
Descriptors: *Pollution taxes(Charges), *Resource allocation, *Industrial wastes,
Pollution abatement, Behavior, Industries, Economics.
It is generally assumed that effluent charges will not result in efficient resource
allocation because of uncertainties facing firms and political constraints. This
study investigates when, and under what conditions, an effluent charge is likely
to improve resource allocation. A mathematical analysis demonstrates an effluent
charge can work in some instances. For the two (or few) firm separable case,
certain specific psychological conjectures must characterize each firm's feeling
about his adversary's potential response. As long as each firm feels that its
adversary's reaction will be less intense than an eye-for-an-eye, an effluent
charge will work. This study further shows an effluent taker case. Retaliation
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is not a viable strategy in the many-firm milieu. Since determining conjectures
is nearly impossible, reservations are expressed regarding the recommendation for
only an effluent charge policy in the few-firm situation. A good environmental
policy might be a dual system composed of effluent charges for effluent-taking
firms coupled with regulation (the current overall policy) for effluent oligopo-
lists. Such a policy would eliminate the uncertainty which characterizes the
oligopolistic situation and allow the advantages of effluent charges to improve
the effluent-takers' market.
75:05G-015
PROSPECTS OF HYDROMETRY IN THE LIGHT OF MODERN TECHNOLOGY,
Framji, K.K.
International Commission on Irrigation and Drainage, p 20-28, January 1975.
44 ref.
Descriptors: *Hydrometry, *Measurement, Technology, Water quality, Water quality
control, Water measurement.
The prospects from the use of modern technology that is, the application of modern
sciences and the use of modern tools and materials are clearly bright for the
development of precise methods and instruments of hydrometry. Sciences and tech-
nologies, such as computers-science electronics, ultrasonic and telemetry, the
use of light-weight plastics and special non-ferrous alloys, the application of
sapecially-designed hydrometric ships and aluminium and fibreglass boats, all
point to future prospects of achieving high degrees of precision and uniformity
in measurements. Also in the not too distant future the use of space craft and
earth satellites for automatic transmission of automatically observed data is
no longer in the realm of fantasy. The sky is the limit.
75:05G-016
CONTROL OF WATER POLLUTION FROM CROPLAND VOLUME 1-A MANUAL FOR GUIDELINE DEVELOP-
MENT,
Stewart, B.A., Woolhiser, D.A., Wischmeier, W.H., Caro, J.H., Frere, M.H.
Agricultural Research Service, U.S. Department of Agriculture, Washington, D.C.
Prepared as a joint publication of Office of Research and Development, EPA, and
Agricultural Research Service, USDA. July 1975. 40 fig, 21 tab,
Descriptors: *Return flow, Sediments, Nutrients, Pesticides, Crop production,
Agriculture, Pollution,.Water quality.
Engineering and agronomic techniques to control sediment, nutrient, and pesti-
cide losses from cropland were identified, described, and evaluated. Methodology
was developed to enable a user to identify the potential sources of pollutants,
select a list of appropriate demonstrated controls, and perform economic analyses
for final selection of controls. The information is presented in the form of
regional maps, decision flow charts, tables, and brief technical highlights.
75:05G-017
NATURAL METHODS OF PURIFYING WASTE WATERS AND UTILIZING THEM IN AGRICULTURE,
BIBLIOGRAPHY, PARTS 1 & 2,
L'vovich, A.I. (Editor)
U.S. Army Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire.
Draft Translation 505, December 1975. 110 p.
Descriptors: *Wastewater, *Agriculture, *Water supply, Irrigation, Sewage
treatment.
This bibliography gives a list of Russian published material on agricultural
utilization of waste waters and natural methods of purifying them on agricultural
and municipal irrigation fields. Materials on questions of self-purification of
the soil from pollutants and sanitary and hygenic evaluations of soi], methods
are presented as completely as possible. The bibliography was updated in 1971
to contain a total of 2,200 title.
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75:050-018
A SYSTEMATIC PROCEDURE FOR TAXING AGRICULTURAL POLLUTION SOURCES,
Walker, W.R.
Colorado State University, Fort Collins, Colorado 80523. Agricultural Engineer-
ing Department.
Engineering Mechanics Section, Civil & Environmental Technology Program,
National Science Foundation, Washington, D.C. 20550. October 1975, 98 p, 12 tab,
22 fig, 33 ref.
Descriptors: *Model studies, *Agriculture, *Pollution, *Colorado River Basin,
*Taxes, Tax rates, Salinity.
A methodology for taxing diffuse agricultural pollution sources is presented
which is based upon deriving linkages between three economic and hydrologic
modeling systems. The procedure involves modeling the hydro-quality system in
the agricultural area in order to identify the specific processes causing water
quality degradation. Then, these results are linked through a pollution coeffi-
cient to an economic externalities model describing the detriments incurred by
downstream uses of water with poor quality characteristics. And finally, an in-
put-output model is developed from which input coefficients and business multipli-
ers are calculated as a means of assessing the local economic impact of alterna-
tive taxing policies. The Grand Valley in Western Colorado is taken as the case
study for this project since it is one of the more significant sources of salinity
in the Colorado River Basin. The analysis evaluates the potential for taxing
agricultural croplands in the valley as a means of controlling salinity related
damages in the lower Colorado River Basin. Four groups of taxing strategies
are investigated: (.1) directly attributable detriments, (2) per acre equivalent
salt loading, (3) salinity or pollution coefficients, and (4) values of gross
revenue per acre. A discussion of how each tax could be applied is presented.
75:050-019
AGRICULTURE AND CLEAN WATER (PROCEEDINGS OF A CONFERENCE ON AGRICULTURAL WATER
POLLUTION CONTROL),
Chappelow, C.C. Jr. (Editor)
Midwest Research Institute, 425 Volker Boulevard, Kansas City, Missouri 64110.
Proceedings of'a Conference held on April 3, 1975, in Kansas City, Missouri.
Descriptors: *Return flow, *Agriculture, *Pollution, Sediments, Erosion, Fertili-
zers, Nutrients, Livestock, Water quality, Water quality control.
A 1-day conference was held to promote a constructive dialogue on the development
of plans for the control of agriculture related nonpoint source pollution arising
from sediment erosion, fertilizer runoff, livestock wastes and pesticide residues.
The morning session was devoted to an analysis of the state of the art on non-
point source pollution related to agriculture with presentations on: (1) region^
al aspects and viewpoints; (2) agricultural pollution control; (3) technical
basis of control; (4) conservation districts; (5) soil conservation; and (6) plant
nutrients. The luncheon session was concerned with an economic overview, consis-
ting of an address on economic problems and opportunities of pollution control.
The afternoon session was designed to explore elements of control strategy plan-
ning for nonpoint pollution from agricultural sources with papers on: (1) the
states' role; (2) one state's approach; and (3) the role of the farmer and agri-
business. The afternoon session was concluded with a panel discussion on the
development of a practicable agricultural pollution control plan. Over 175 indi-
viduals from 20 different states representing local, state, regional, and federal
agricultural and environmental agencies attended the conference. Also, included
in the 75 different organizations represented at the conference were attendees
from farmer associations, educational institutions, and agribusiness.
75:05G-020
ANNOTATED BIBLIOGRAPHY ON TRICKLE IRRIGATION,
Smith S.W., Walker, W.R.
Colorado State University, Fort Collins, Colorado. Agricultural Engineering
Department, Environmental Resources Center.
Information Series No. 16, June 1975. 61 p.
(See 75:03F-039)
185
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75:05G-021
THE DETERMINATION OF CADMIUM, LEAD, COPPER AND ZINC IN GROUND WATER, ESTUARINE
SEWAGE AND SEWAGE EFFLUENT BY ANODIC STRIPPING VOLTAMMETRY,
Gardiner, J., Stiff, M.J. ,
Water Research Centre, Stevenage Laboratory, Elder Way, Stevenage, Herts, England.
Water Research Vol. 9, No. 5/6, p 517-523, May-June 1975. 1 fig, 1 equ, 8 tab,
22 ref.
Descriptors: *Water quality, *Water quality control, *Trace elements, *Cadmium,
Lead, Copper, Water pollution.
Anodic stripping voltammetry (ASV) using the thin-film mercury electrode was
shown to be a successful technique for the determination of total (free plus com-
plexed) trace metal concentrations in various types of aqueous sample. The method
developed involved the minimum of sample treatment and required only simple and
inexpensive equipment. The practical limit of sensitivity was about 0.1 micro-g/1
for cadmium, lead and copper. The determination of zinc was found to be compli-
cated by the formation of an intermetallic compound with copper. Interference by
other trace metals and by complexing agents was investigated. Photochemical oxi-
dation for the decomposition of complexes of the metals with organic ligands in
filtered sewage and sewage effluent was found to be successful, although the
process is slower for cadmium than for the other metals. Good agreement with a-
tomic absorption spectroscopy was obtained for all the types of aqueous sample
investigated. Possible improvements of the ASV technique are discussed.
75:05G-022
DETERMINATION OF CHLORIDE IN WATER WITH A HgS/Hg2C12 ELECTRODE,
Sekerka, I., Lechner, J.F., Wales, R.
Canada Centre for Inland Waters, Burlington, Ontario, Canada.
Water Research Vol. 9, No. 7, p 663-665, July 1975. 1 fig, 4 tab, 13 ref.
Descriptors: *Chloride, *Water quality, *Water quality control, Waste water.
Electrodes, Laboratory equipment.
The application of a new type of solid state chloride ion sensitive electrode,
based on HgS/Hg2C12 has been investigated for manual and automated measurements
of chloride in natural, industrial and waste water. The electrode displays Ner-
stian response for the range 0.05-3.500 ppm of chloride and can be used for con-
centrations down to 0.05 ppm (5 x 10 to the minus 7th power M). Achieved values
of standard deviation, recovery and comparative tests from a variety of water
samples are highly satisfactory- Inherent simplicity and sensitivity together with
obtained results demonstrate the usefulness of the proposed method in routine
analyses.
75:05G-023
EFFECT OF SURFACE APPLIED SULFURIC ACID ON WATER PENETRATION INTO DRY CALCAREOUS
AND SODIC SOILS,
Yahia, T.A., Miyamoto, S., Stroehlein, J.L.
Arizona Univ-, Tucson, Dept. of Soils, Water and Engineering.
Soil Science Society of America Proceedings, Vol. 39. No. 6, p 1201-1204, November-
December 1975. 3 fig. 4 tab, 8 ref.
Descriptors: *Soil treatment, *Calcareous soils, *Revegetation, *Infiltration,
Penetration, Sulfur compounds, *Southwest U.S., Gypsum, Dispersion, Percolation,
Soils, Calcium carbonate, Surface waters. Vegetation regrowth, Range management,
Chemical wastes, Irrigation practices, Chemicals, Physical properties. Soil amend-
ments, Acids, Alkaline soils. Reclamation, Soil structure, Soil moisture.
Sulfuric acid, a surplus by-product of copper smelters in the Southwest, was
studied to determine a possible role in reclamation and revegetation of calcareous
and sodic range soils. The rate of water penetration into dry calcareous soils
was measured in columns as well as boxes after concentrated (93%) sulfuric acid
was applied to the soil surfaces. The rate of penetration increased with increasing
186
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acid application rates, but then decreased, with optimum application rates ranging
from 5 to 15 metric tons/ha. Acid was especially effective in increasing the rate
of penetration into sodium-affected calcareous soils. When acid was applied as
a band on the soil surface, the wetting front advanced in an elongated semicircular
form with depth. Surface applied acid was more effective than surface applied
gypsum in increasing water penetration into sodium-saturated soils. Sulfuric
acid may be useful for increasing water penetration into and subsequently aiding
in revegetation of sodium-affected soils of semi-arid regions.
75:05G-024
A GENERAL LINEAR APPROACH TO STREAM QUALITY MODELING,
Arbabi, M., Elzinga, J.
IBM Corporation, Gaithersburg, Maryland 20706.
Water Resources Research Vol. 11, No. 2, p 191-196, April 1975. 3 tab, 14 ref.
Descriptors: *Dissolved oxygen, Water quality, Water quality control, Water
pollution, Model studies, Optimization.
The problem of meeting stream dissolved oxygen standards while optimizing some
objective is treated. New properties of the oxygen sag equation allow the con-
straint set of such mathematical programs to be described to a high degree of ac-
curacy by linear inequalities; except for upper and lower bounds on pollutant dis-
charges, three linear constraints at most are required per reach. Constraint
elimination techniques are developed that can further reduce the number of con-
straints necessary. As a means of highlighting the potential power of these
techniques to large-scale models they are applied to two well-known examples from
the literature.
75:05G-025
COMPARISON OF METHODS FOR THE DETERMINATION OF TOTAL PHOSPHORUS IN WATERS CONTAINING
PARTICULATE MATERIAL,
O'Connor, P.W., Seyers, J.K.
Grants from the Ministry of Agriculture and Fisheries, and The Department of
Scientific and Industrial Research, New Zealand.
Journal of Environmental Quality, Vol. 4, No. 3, 1975. p 347-350, 4 tab, 18 ref.
Descriptors: *Phosphorus, Water quality, Water quality control, Water sampling,
Sediments.
Perchloric acid digestion compared favorably with Na2CO3 fusion for the determina-
tion of total P in a range of waters containing varying concentrations of both P
and particulate material. The recovery of particulate P by persulfate digestion
tended to decrease with increasing particulate material concentration in both
natural unfiltered samples and in filtered samples to which particulate material
was added. Recovery of added soil particulate P by persulfate digestion also
decreased with increasing particle size. Low recovery of P by persulfate digestion
was caused by the incomplete extraction of P occluded within oxides and hydrous
oxides of iron. Between 58 and 86% of the P not recovered by persulfate digestion
was in the inorganic form. Persulfate digestion is not recommended for the
determination of total P in waters containing particulate inorganic materials of
soil origin. Perchloric acid digestion is considered to be a more suitable method
for such samples.
75:056-026
WILLINGNESS TO PAY AS A BEHAVIOURIAL CRITERION FOR ENVIRONMENTAL DECISION-MAKING,
Fischer, D.W.
Waterloo University, (.Ontario) . Dept. of Man-Environment Studies.
Journal of Environmental Management,. Vol. 3, No. 1, p 29-41, 1975. 1 fig, 39 ref.
Descriptors: *Environment, *Decision making, *Social aspects, Social values,
Methodology, Attitudes, Economics, Behavior, Market value, Pricing, Surveys, Pol-
lution taxes(Charges).
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The economic nature of environmental quality questions and the inherent problems
in the use of willingness-to-pay as a behavioral criterion for environmental mana-
gers is summarized. Development of an adequate theory or structure of social value
which incorporates a variety of variables is necessary before attempting to apply
economic techniques to environmental quality decisions, since environmental quality
levels have little to do with market transactions or exchanges. Willingness-to-pay
studies suffer from a lack of adequate information. Environmental damages are
often perceived to be less than actually exist, and, in some cases, are concealed.
Economic incentives for displaying, distorting, or hiding information are also
important considerations, as is people's perceptions of their role in society.
Willingness-to-pay evaluations ignore those who are not directly involved and those
of future generations, both of which groups may have a strong demand for high
environmental quality. Problems in determining actual individual preferences, and
in the use of prices are also considered. The use of surveys in willingness-to-pay
analysis are subject to the disparity between what people say and what they
mean.
75:050-027
MODELS IN WATER QUALITY PLANNING,
Abendt, R.W.
Institut fur Siedlungswasserwirtschaft, Universitat Karlsruhe, Karlsruhe (Federal
Republic of Germany)
Ecological Modelling, Vol. 1, No. 3, p 205-217, September 1975. 7 fig, 2 equ,
11 ref.
Descriptors: *Model studies, *Mathematical modeling, Water quality. Decision
making, Water quality control, Planning.
This paper is to show the range of applicability of water quality models. It is
intended to clarify the purpose of modelling with respect to the exactness of re-*
suits and to investigate problems of data collection. The data quantity and ob-
jective of modelling influence the model structure, i.e., the mathematical complex-
ity. Two principal errors are investigated: first, the error caused by the
mathematical abstractions of the natural processes in a model, and on a subsequent
level, the wrong parameter estimates in a model. Furthermore, the difference
between a deterministic descriptive, and a statistical approach, is discussed. In
both model types, input and objectives are the same. But the methodology is
fundamentally different. A practical example is presented based on a two-parameter
water quality model. It is the Neckar River quality model, the limits and practi-
cability of which are discussed in this context.
75:056-028
MATHEMATICAL MODELLING AND ENVIRONMENTAL DECISION-MAKING,
Biswas, A.K.
Environmental Systems Branch, Department of Environment, Ottawa, Ontario. (Canada)
Ecological Modelling, Vol. 1, No. 1, p 31-48, May 1975. 1 fig, 15 ref.
Descriptors: *Mathematical modeling, *Model studies, *Decision-making, Water ~
resources, Environment, Environmental engineering.
The primary role of a decision-maker is to make right decisions on the basis of
available information and within the allowable time and resources constraints. The
two basic types of models used for decision-making, technocratic and incremental,
are discussed, and so are the common criteria of the decision-making process in a
real world. The intensity and diversity of demands on our limited water resources
have increased to such an extent that decision-makers are finding it increasingly
difficult to consistently attain the needed flexibility and dexterity. Thus, even
though decision-making has become exceedingly complex at present, and will become
more so in the future, it is apparent that the average decision-maker has been
provided with few, if any, new tools and concepts in the past several decades. One
of these very few techniques is systems analysis.
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Section XXVII
WATER RESOURCES PLANNING
TECHNIQUES OF PLANNING (GROUP 06A)
75:06A-001
A SCREENING MODEL FOR WATER RESOURCES PLANNING,
Viessraan, W. Jr., Lewis, G.L., Yomtovian, I., Viessman, J.J.
Nebraska University, Lincoln. Water Resources Research Institute
Water Resources Bulletin, Vol. 11, No. 2, p 245-255, April 1975. 2 fig, 3 tab,
3 ref.
Descriptors: Water resources, *Planning, *Linear programming, *Economic effi-
ciency, *Simulation analysis, *Flood Control, Optimization, Regional development,
Management, Streamflow, Costs, Benefits, Flood damage, Alternative planning.
Surface waters, Water utilization, Reservior storage, Recreation, Constraints,
Evaluation, Hydrologic aspects, Mathematical models, Systems analysis, *Nebraska.
Optimization and simulation are combined in a procedure to select the most
efficient arrangement of components for regional water resources development
and management policy. The technique is applied to the Elkhorn River basin in
Nebraska, which extends over 7,000 square miles and includes 184 proposed res-
ervoirs. Structure sizes, locations and operating policies are selected for
optimal plans based on economic efficiency and regional development. Model input
consists of an historical or simulated sequence of unregulated annual and within-
year period streamflows at each water use or management site. The proposed
model is intended as a preliminary screening tool; it is easy to apply, has
minimal data requirements, and has a sound physical base. Use of the model,
which utilizes linear programming, in decision making for flood control is-con-
sidered in detail. Objectives employed in evaluating alternatives include both
net annual benefit maximization and annual cost minimization. Results indicate
that substantial savings in time and costs over conventional planning techniques
are effected. Agreement between model output and agency design values was noted.
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Section XXVIII
WATER RESOURCES PLANNING
COST ALLOCATION, COST SHARING, PRICING/REPAYMENT (GROUP 06C)
75:06C-001
AN IMPLICIT APPROACH TO PRICING AGRICULTURAL WATER TRANSFERS TO URBAN USES,
Walker, W.R., Skogerboe, G.V.
Colorado State University, Agricultural Engineering Department, Fort Collins,
Colorado 80523.
Water Resources Bulletin, Vol. 11, No. 4, p 751-758, August 1975. 6 fig, 6 ref.
Descriptors: *Model studies, Mathematical modeling, Optimization, Urbanization,
Water quality, Water transfer, Water shortage, Water quality standards.
The increased agricultural efficiency of the American farmer has been a substan-
tial impetus to this nation's rapid urbanization. In many western regions where
total water supplies are limited, urbanization has required the transfer of
heretofore agricultural water rights to the urban use. A major problem in such
transfers has been the value or price of the water. A management level model of
a typical urban water system was developed to optimize water supply, distribution,
and wastewater treatment alternatives. The values of agricultural transfers were
determined as the cost advantages of increasing allowable reuse levels of urban
effluents which imply the use of a downstream right. This procedure is justified
by the economic theory of alternative cost. Results for a test application to
the Denver, Colorado area indicate values on the order of $1,000 per acre-foot of
transferable water depending on effluent water quality restrictions and operational
policies.
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Section XXIX
WATER RESOURCES PLANNING
WATER LAW AND INSTITUTIONS (GROUP 06E)
75:06E-001
A FRAMEWORK FOR EVALUATING INSTITUTIONAL AND SOCIO-ECONOMIC ISSUES OF LAND
TREATMENT OF WASTE WATER,
Christensen, L.A.
Economic Research Service, United States Deaprtment of Agriculture, Upper Darby,
PA 19082
Journal of Environmental Quality, Vol. 4, No. 2, p 145-153, April-June 1975.
1 fig, 1 tab 27 ref.
Descriptors: *Waste water disposal, *Waste water, *Waste water treatment,
*Land management, *Instituional constraints, Research priorities. Agriculture.
Land treatment of waste waters is receiving considerable attention as a waste
water management alternative to meet water quality requirements. The many
questions raised with the land treatment approach encourage a multidisciplinary
planning approach. The systematic investigation of institutional and economic
questions should be made concurrent with technical and engineering studies. An
investigation of this waste water treatment alternative must address the questions
of (i) what institutional arrangements will be used to acquire the use of the
necessary land, and (ii) how the land treatment system will be managed. Many fac-
tors influence the acreage required for land treatment systems including community
size, the type of waste water being treated, management systems used, land avail-
ability, and soil type. An extensive area would be required for a large metropol-
itan area such as Detroit. Smaller communities or power plants would require
less area. A number of ways to acquire rights to land are suggested, each with
different implications for the affected farmers and the authority responsible for
the operation of the system. These include fee simple acquisition, easement pur-
chases, and the formation of waste water cooperatives. Some potential management
options for fee simple sites include purchase and manage, and purchase and lease-
back.
75:06E-002
CONFLICTS IN WATER TRANSFER FROM IRRIGATION TO MUNICIPAL USE IN SEMIARID ENVIRON-
MENTS ,
Cluff, C.B., DeCook, K.J.
Arizona Water Resources Research Center, Tucson.
Water Resources Bulletin, Vol. 11, No. 5, p 908-918, October 1975. 4 fig, 3 tab,
8 ref.
Descriptors: *Water transfer, *Urbanization, *lrrigation water, *Competing uses,
*Water reuse, Land use, *Crop production, Municipal water, Water rights, Water
delivery, Water demand, Water law, Water distribution, Legal aspects, Arizona,
Alternative water use, Administration, Institutional contraints.
Continued transfer of water from agricultural to urban use is seen as inevitable
in Arizona as a result of increased population pressure. Conflict thus generated
has been minimized in the Phoenix region where direct urbanization of irrigated
land has shifted water supply from one use to another on the same site. This
is not the case in the Tucson region, where irrigated lands are more remote. To
obtain water for municipal use, the City, entirely dependent on groundwater, is
buying and retiring farmlands in an adjacent agricultural area in order to acquire
the water rights tied to the land by Arizona water law. Forced farmland retire-
ment has created conflicts and problems including planning for future use of the
land, as reclamation is especially difficult in semiarid regions. The loss of
food crop production occurs in a time of accelerating world food shortage. Ex-
change of treated municipal waste-water for irrigation water is being considered,
but many attendant problems must be resolved.
191
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Section XXX
WATER RESOURCES PLANNING
ECOLOGIC IMPACT OF WATER DEVELOPMENT (GROUP 06G)
75:06G-001
NATURAL AND AGRICULTURAL ECOSYSTEMS,
Smith, D.F., Hill, D.M.
College of Advanced Education, Launceston, Tasmania, Australia.
Journal of Environmental Quality, Vol. 4, No. 2, p 143-145, April-June 1975.
1 fig.
Descriptors: *Ecosystems, Agriculture, Management.
It is argued that the task of creating awareness of environmental problems will
require more than the bringing together of papers from a range of disciplines.
It will depend on new consciousness and channels of communication. As an example
of problems with terms, this paper analyses the use of natural and agricultural
ecosystems, suggesting that on all valid criteria these form a continuum, rather
than two discrete systems.
75:06G-002
PROCEDURE FOR SELECTING A MINIMAL ENVIRONMENTAL IMPACT ROUTING FOR A WATER CONVEY-
ANCE CANAL,
Wells, D.M., Mertes, J.D., Allen, B.L., Click, A.N.
Texas Tech Univ., Lubbock, Dept. of Civil Engineering.
Water Resources Bulletin. American Water Resources Association, Vol. 11, No. 4,
p 714-733, August 1975. 12 fig, 1 tab, 4 ref.
Descriptors: *Environmental effects, *Comprehensive planning, *Water resources
development, Water conveyance, Canals, Routing, Assessment, Coasts, Evaluation,
Water supply, Texas, Multiple-purpose projects, Computers.
Several techniques for selecting a least environmental impact corridor have been
proposed. Two approaches have been found workable: computer graphics and overlay
mapping. This report combines features of both approaches to determine an appropri-
ate routing for a water conveyance canal. The evaluation study was conducted
by an interdisciplinary planning team. Environmental factors were mapped and
weighted on overlay maps. Alternative routes were identified and carefully studied.
Several critical environmental implications were noted. Aesthetic factors, out-
door recreation interpretation, visitor safety and disruption of human and animal
travel routes were considered. Evaluation of an environmental analysis procedure
requires close examination of the project objectives, scope, and ultimate decision-
making body that will ultimately utilize the findings. Size and scale of project
play important roles when examining cost figures. The overlay map procedure pro-
vides an effective graphic media through which the process of selecting and evalua-
tina alternative linear corridors can be presented. The importance of an inter-
disciplinary planning team cannot be stressed enough.
192
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Section XXXI
RESOURCES DATA
DATA ACQUISITION (GROUP 07B)
75:07B-001
A DUAL-INTERVAL, LIGHT-ACTIVATED SIGNAL GENERATOR—ITS APPLICATION TO SEDIMENT
SAMPLING,
Edens, C.D., DeCoursey, D.G.
Agricultural Research Service, United States Department of Agriculture, Chickasha,
OK.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 3,
p 505-507, May-June 1975. 4 fig.
Descriptors: *Sediment load, *Sediment transport, *Sediment yield, *Sampling.
Since records of sediment in the field are not available on a continuous basis,
water samples must be collected periodically and analyzed for concentration.
The device described is a less expensive improvement over available stage and
time-activated methods of determining when samples should be taken. To signal
the sampler, the device uses light-sensitive rectifiers, activated by light
shining through the holes in a disc-mounted on the stage recorder.
75:078-002
BULK DENSITY SAMPLER FOR DEEP SOIL PROFILES,
Holtzclaw, K.M., Rible, J.M., Pratt, P.F.
California University, Riverside.
Soil Science Society of America Proceedings, Vol. 39, No. 6, p 1220-1223,
November-December 1975. 4 fig, 2 tab, 3 ref.
Descriptors: *Sampling, *Bulk density, *Instrumentation, *Soils, *Soil profiles,
Drilling, Drilling equipment, Fertilizers, Irrigation, Salts.
A bulk density sampler, adapted from a conventional commercial type, was con-
structed and used to obtain soil samples at more than 50 sampling sites from depths
to 30 m. This sampler increased the speed with which samples were taken because
it was readily added to or detached from the drilling unit between sequences of
drilling. Evaluations showed that the sampler obtained bulk density values quite
comparable to those found with an undisturbed soil core method.
193
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Section XXXII
RESOURCES DATA
EVALUATION, PROCESSING AND PUBLICATION (GROUP 07C)
75:07C-001
A TAX SYSTEM FOR GROUNDWATER MANAGEMENT,
Maddock, T., Ill, and Haimes, Y.Y.
Geological Surver, Reston, Virginia.
Water Resources Research, Vol. 11, No. 1, p 7-14, February 1975. 4 tab, 14 ref.
Descriptors: *Water management(Applied), *Taxes, *Groundwater resources,
Water allocation(Policy), Administration, Water distribution(Applied), Water
rights, Water conservation, Irrigation water.
A tax scheme was developed to create an incentive among users to conserve ground-
water and reduce the external diseconomies that pumping produces. Quotas are
established for wells by using an agricultural management model. If a user
pumps more than the quota established for his well, he may be assessed a tax;
if a user pumps less than his quota, he may be entitled to a rebate. However,
taxes are collected and redistributed in such a way that zero taxes are accumu-
lated from year to year.
194
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Section XXXIII
ENGINEERING WORKS
STRUCTURES (GROUP 08A)
75:08A-001
DRAINAGE MAINTENANCE PROGRAMS IN OHIO COUNTIES,
Nolte, B.H.
The Ohio State University, Columbus, Ohio.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975, Chicago, Illinois. 4 p, 2 tab, 7 ref.
Descriptors: -*Drainage, *Drainage engineering, Ohio, Cost analysis.
Drainage maintenance programs have increased dramatically in Ohio counties during
the past 18 years. Over 11,000 km of channel are being maintained. It is estima-
ted that an additional 970,000 hectares could have better drainage from future
outlet construction and maintenance in Ohio.
195
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Section XXXIV
ENGINEERING WORKS
HYDRAULICS (GROUP 08B)
75:08B-001
CORRUGATED PLASTIC DRAIN TUBING USED AS UNDERGROUND CONDUIT,
Misra, M.K., Beasley, R.P.
Missouri University, Columbia. Department of Agricultural Engineering.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 2,
p 260-262, March-April 1975. 7 fig, 2 tab, 2 ref.
Descriptors: *Drains, *Drainage systems, *Excess water (Soils), *Hydraulic
models, Drainage practices, Pipes, Storm drains, Drainage water, Tiles,
Conduits, Subsurface drains, Drainage, Sediment transport, Soils, Movement,
Sediments.
Model studies were made to investigate the effect of high water velocity on the
extent of soil movement when corrugated plastic drain tubing is used as conduits
for underground terrace outlets on steep slopes. No significant amount of
sediment was drawn into the tubing, even when the slope was 10% and velocity
approached 9 ft. per sec. The magnitude of the flow from the tubing to the soil
was low in cohesive soils. But, with less cohesive soils this outflow was
greater and there was considerable movement of soil from around the tubing.
75:088-002
GRAPHIC DETERMINATION OF SUB-MAIN PIPE SIZE FOR SOLID-SET SPRINKLER IRRIGATION
ON STEEP, NON-UNIFORM SLOPES,
DeTar, W.R.
Pennsylvania State University, University Park, PA, Department of Agricultural
Engineering.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 3,
p 503-504, 507, May-June 1975. 3 fig, 1 tab, 1 ref.
Descriptors: *Sprinkler irrigation, *Irrigation, *Irrigation engineering,
*Hydraulic design, *Hydraulics.
Analytical solutions to the problem of selecting the proper size for sub-main
descending steep, irregular slopes for solid-set irrigation systems can be
tedious. A simple graphical method is presented here for obtaining fairly
uniform pressures along the sub-main. The method is particularly useful for
any solid-set system that repeatedly uses the same lateral size and spacing.
75:08B-003
GENERALIZED NOMOGRAPHIC SOLUTION OF HOOGHOUDT EQUATIONS,
Sakkas, J.G.
Public Power Corporation, Athens (Greece). Hydroelectric Project Design Branch.
Journal of the Irrigation and Drainage Division, Proceedings of American Society
of Civil Engineers, Vol. 101, No. IRl, Proceedings Paper 11182, p 21-39, March
1975. 4 fig, 8 tab, 16 ref, 2 append.
Descriptors: *Drainage, *Drains, *Groundwater, *Water Table, Dupuit-Forchheimer
theory, Hydraulic conductivity, Rainfall, Irrigation water. Graphical analysis.
The equation of drain spacing developed by Hooghoudt has gained considerable
popularity among drainage design engineers because it is sufficiently accurate
and possesses a simple mathematical expression. The latter is due to the notion
of equivalent depth which he introduced. On the contrary, the application of the
equation is quite cumbersome, requiring a trial-and-error procedure. In recent
years drainage design for unsteady flow conditions also utilized the notion of
equivalent depth. To simplify the use of both the drain spacing and the equiva-
lent depth equations, they were put into dimensionless form containing fewer
independent variables. An array of values suffices for quick and inexpensive
determination of the equivalent depth. Tables of dimensionless equivalent depth
196
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also were prepared. A unique dimensionless nomographic solution of the drain
spacing equation was obtained and was displayed in a set of five graphs. Work
relevant to Hooghoudt equations by two investigators was analyzed with the aid
of this analysis.
75:08B-004
POINT SOURCE DISPERSION IN TURBULENT OPEN CHANNELS,
Atesmen, K.M.
Bogazici University, Istanbul (Turkey), Department of Mathematics.
Journal of the Hydraulics Division, Proceedings of American Society of Civil
Engineers, Vol. 101, No. HY7, Paper 11413, p 789-799, July 1975. 12 fig, 7 ref.
2 append.
Descriptors: *Open channel flow, *Dispersionr *Numerical analysis, *Fluid mecha-
nics, Hydraulics, *Turbulent flow, Distribution, *Velocity, Mathematics, Analysis,
Variability.
The effect of the initial distribution of dispersant was investigated by obtaining
solutions for different initial instantaneous point and plane source distributions.
The governing equations were converted to a tractable system of moment equations
which was solved by a numerical method for the zeroth, first, second, third, and
fourth moments of the longitudinal concentration distribution. The initial instan-
taneous point source was located at 9, 9.25, 9.50, 9.75, and 1.0 fractions of the
flow depth. During the initial period of dispersion, the convective transport
produced a considerable deviation of the moments of the dispersing cloud from
the Gaussian long dispersion time conditions. The longitudinal dispersion in a
turbulent open-channel flow was found to be strongly dependent on the vertical
location of an instantaneous point source.
75:08B-005
DESIGN OF DRIP IRRIGATION MAIN LINES,
Wu, I-p.
Hawaii University, Honolulu. Department of Agricultural Engineering.
Journal of the Irrigation and Drainage Division, Proceedings of the American
Society of Civil Engineers, Vol. 101, No. IR4, Proceedings paper No. 11803,
p 265-278, December 1975. 9 fig, 3 tab, 12 equ, 9 ref.
Descriptors: *Irrigation, *Irrigation design, *Irrigation systems, *Energy
gradient, Optimization, Computer programs, Cost comparisons, Pipes, Design, Size,
Simulation analysis, Dynamic programming, Equations, Evalation, Hazen-Williams
equation, Systems analysis.
A drip irrigation system should be designed to meet water requirements of crops,
to possess the capacity to provide extra water during unusually dry period, to
distribute water into fields with acceptable uniformity, and to have the lowest
cost. The main lines of a drip irrigation system can be designed using a straight
energy gradient line. This provides a very simple technique for selecting main
lines of a drip irrigation system can be designed using a straight energy gradient
line. This provides a very simple technique for selecting main line sizes that
can be applied especially to evaluate alternative field layouts. An optimal
shape of the energy gradient curve is determined as a curve a little bit below
the straight energy gradient line. The cost difference between using the straight
energy gradient line and the optimal energy gradient line is small, and only
around 2%. The developed technique can be used for any kind of topographic condi-
tion, uniform or nonuniform, up and down slopes. A straight line energy gradient
line can be established when a main line provide is drawn and the available
water pressure is determined. The concept can be applied for different types of
pipes for sprinkler system design, for water supply pipe systems, or transporting
systems for other fluids.
75:08B-006
RESISTANCE TO FLOW IN A COMBINED CHANNEL,
Rice, C.E., Araveeporn, R.
Oklahoma State University, Stillwater. Department of Agricultural Engineering.
197
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Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 5,
p 869-872, September-October, 1975. 6 fig, 3 ref.
Descriptors: *Open channel flow, *Flood plains, *Roughness(Hydraulic), Hydraulics,
Streams, Roughness coefficient, Channel flow, Hydraulic radius, Mannings equation,
Flow, Laboratory tests, Flow resistance.
These experiments studied the flow characteristics in a combined channel with
different hydraulic properties, main channel to floodplain widths and areas,
slopes, and roughness. The results showed: (1) the hydraulic radius as ordinari-
ly computed in a regular channel results in erroneous discharge values for a com-
bined channel in the depth range immediately above bankfull stage of the main
channel; (2) the floodplain flow appeared to have some retarding effect on the
flow in a main channel; (3) the combined channel Manning coefficient increased
as the floodplain width increased; (4) as the flood plain width decreased, the Man-
ning coefficients for the floodplain and main channel approached the same value at
floodplain to main channel depth ratios less than about 0.4; (5) the Manning coef-
ficient for the combined channel reflects the effect of channel geometry as well
as the effects of boundary roughness and slope; (6) the hydraulic radius of the
floodplain was greater with a divider separating the two sections than without a
divider separating the two sections than without a divider for the same depth of
flow in the main channel; (7) none of the methods commonly used to compute uniform
flow discharge in a combined channel gave good results over the complete range of
flow depths; and (8) except at very shallow floodplain depths, there was no differ-
ence in water surface elevation between the main channel and floodplain sections.
75:086-007
VORTEX VELOCITY PREDICTION WITH EMPHASIS DIRECTED TOWARD VORTEX TUBE SEDIMENT
TRAP DESIGN,
Edling, R.J., Barfield, B.J., Haan, C.T.,
Agricultural Engineering Department, University of Nebraska, Scottsbluff,
Nebraska.
Presented at the 1975 Winter Meeting of the American Society of Agricultural
Engineers, December 15-18, 1975. Chicago, Illinois. 25 p, 5 fig, 2 tab, 23 equ,
14 ref.
Descriptors: *Sediments, *Sediment control, *Mathematical model, *Model studies.
The variation in coefficients relating mean velocity, wall velocity and vortex
perimeter velocity indicate the values from the empirical technique, if used,
could only be considered as rough estimates. The agreement between the expected
pattern of stream function and the predicted pattern and approximation of upper
slot and mainstream measured velocities by the mathematical model encourage fur-
ther work with the model. Closer agreement between measured and predicted values
is desirable, however, it is felt that the present model gives a first order
approximation. It is recommended that changes in the lower boundary conditions
for turbulence kinetic energy, dissipation and vorticity be studied. Successful
prediction of the point mean velocity and turbulent parameters in conplex flows
would have many applications.
75:08B-008
ANNOTATED BIBLIOGRAPHY ON TRICKLE IRRIGATION,
Smith, S.W., Walker, W.R.
Colorado State University, Fort Collins, Colorado. Agricultural Engineering
Department, Environmental Resources Center.
Information Series No. 16, June 1975. 61 p.
(See 75:03F-039)
75:08B-009
ENERGY GRADIENT LINE FOR DRIP IRRIGATION LATERALS,
Wu, I-p., Gitlin, H.M.
University of Hawaii, Honolulu, Hawaii.
198
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Journal of the Irrigation and Drainage Division, Vol. 101, No. IR4, p 323-326,
December 1975. 1 fig, 14 equ, 2 ref, 1 append.
Descriptors: *Irrigation, *Irrigation design, *Hydraulics, *Irrigation systems,
Mathematical analysis, Computers.
The derived mathematical equations for the energy gradient lines can be applied
to hydraulic analysis of irrigation systems to both drip and sprinkler. Also,
the equations can be used to simplify computer simulations for irrigation system
studies and design.
199
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Section XXXV
ENGINEERING WORKS
SOIL MECHANICS (GROUP 08D)
75:080-001
SOIL BULK DENSITIES AFTER THIRTY YEARS UNDER DIFFERENT MANAGEMENT REGIMES,
Northup, M.L., Boyle, J.R.
Grand Valley State Colleges, Allendale, Mich.
Soil Science Society of America Proceedings, Vol. 39, No. 3, p 588, May-June 1975,
Descriptors: *Soil density, *Bulk density, *Nutrients, *Cultivation, Soil
properties, Soil investigations, Soils, Soil compaction.
Variability of soil bulk density must be known to convert accurately concentra-
tions of nutrients in a soil to absolute quantities. This study shows that culti-
vation increases the bulk density of some soils and simultaneously lowers its
variability. Extablishment of prairie and pine vegetation on cultivated soils
has not created significant differences in this property between vegetation types
in 30 years.
200
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Section XXXVI
ENGINEERING WORKS
ROCK MECHANICS AND GEOLOGY (GROUP 08E)
75:08E-001
SHALE CHISELING - EFFECT ON WATER YIELD,
Shanholtz, V,0., Burford, J.B., Engman, E.T.
Virginia Polytechnic Institute, and State University, Blacksburg. Agricultural
Engineering Department.
American Society of Agricultural Engineers, Vol. 18 No. 6, p 1100-1104,
November-December 1975. 6 fig, 1 tab, 21 ref.
Descriptors: *Water yield, *Shales, *Chiseling, Runoff, Erosion, Hydrology.
The Soil and Water Conservation Research Division of the Agricultural Research
Division of the Agricultural Research Service (ARS), in cooperation with the
Potomac Valley Soil Conservation District, the SES, and the West Virginia Agricul-
tural Experimental Station initiated hydrologic studies at a site located near
Moorefield, West Virginia. Their general objectives were to study the basic
factors affecting the hydrograph of surface runoff from pasture on shallow soils
formed on shale and to evaluate the effect of shale chiseling on water yield and
the hydrograph of surface flow. Generally, this report will be limited to the
hydrologic response of the experimental area as reflected by water yields.
201
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Section XXXVII
ENGINEERING WORKS
MATERIALS (GROUP 08G)
75:08G-001
OUTFLOW FROM VARIOUS SUBSURFACE DRAINAGE MATERIALS,
Sommerfeldt, T.G.
Research Station, Agriculture Canada, Lethbridge, Alberta, Canada.
Transactions of the American Society of Agricultural Engineers, Vol. 18, No. 1,
p 85-88, 94, January-February 1975. 8 fig. 2 tab, 16 ref.
Descriptors: *Drainage, *Drainage engineering, *Drainage systems, *Drains,
Lysimeters.
In lysimeters, the discharge from 55-, and 105-mm-ID perforated plastic drains
and 105-mm-ID clay tile drains, with and without gravel or fiberglass envelopes,
was determined in CL and FSL soil. In the field, the rate and volume of discharge
from 65-mm flexible plastic and 105-mm clay tile drains, installed with fiberglass
envelopes in 1968, were determined between 1969 and 1971. The soil, which was
coarse textured, was flooded five times in 1969, six times in 1970, and twice in
1971. Generally, no one drain produced greater discharge than another.
75:08G-002
STRUCTURAL PERFORMANCE OF BURIED PLASTIC DRAIN TUBING,
Watkins, R.K., Shupe, O.K., Willardson, L.S.
Engineering Experiment Station
American Society of Agricultural Engineers, Vol. 18 No. 6, p 1082-1084, 1088,
November-December 1975. 6 fig, 5 ref.
Descriptors: *Drainage, *Drains, *Drainage Practices, *Plastic pipes. Plastics,
Backfill.
Structural performance tests of corrugated high density polyethylene plastic
drain tubing in soil showed that ring deflection is influenced primarily by
settlement of the soil around the tubing and secondarily by bedding. The tubing
deflects mostly during the backfilling operation. Excessive ring deflection ini-
tiates wall buckling and reversal of curvature. Care in forming bedding and in
placing sidefill material reduces ring deflection. Reversal of curvature and
wall buckling are not total structural failures but do represent performance limits
for the tubing.
75:08G-003
ELONGATION CHARACTERISTICS OF CORRUGATED PLASTIC TUBING,
Schwab, G.O., Brehm, R.D.
Ohio State University, Agricultural Engineering Department.
American Society of Agriculture Engineers, Vol. 18 No. 6, p 1114-1117, November-
December 1975. 5 fig 7 ref.
Descriptors: *Plastic pipe, *Plastics, *Drainage, *Drainage design, Backfill.
The widespread adoption of corrugated plastic tubing for subsurface drainage in
Europe and in the United States has taken place since about 1962. Because of
such rapid acceptance, test procedures and research have not kept pace with usage.
Elongation (stretch) is one of many factors which influences the diametral stiff-
ness (also called strength) of corrugated tubing. The objectives of this study
were to determine the effect of tube elongation on stiffness, to develop a labor-
atory test procedure to measure this effect, and to evaluate elongation of tubing
installed with different equipment and varying conditions in the field. Tubing
sizes were limited to 76, 102, and 152-mm (3,4, and 6-in.) diameters because
larger sizes are normally not installed in continuous lengths and stretching is
not a problem.
202
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Section XXXVIII
AUTHOR INDEX
Abendt, R.W.
75:05G-027
Abudelgawad, G.
75:02K-005
Aceves-N, E.
75:030-004
75:050008
Ackerson, R.C.
75:021-010
Addink, J.W.
75:02G-009
Adriano, 0. C.
75:02G-006
75:058-013
Ahuja, I.R.
75:02G-031
Alberts, E.E.
75:020-004
Aldabagh, A.S.Y.
75:03F-002
Aleti, T.
75:056-057
Alexander, V.
75:05B-017
Aljibury, F.K.
75:03F-083
Alleman, R.
75:03F-077
Allen, B.I.
75:06G-002
Allen, M.J.
75:05A-013
Allen, S.E.
75:03F-012
75:03F-056
Allison, G.B.
75:02F-025
Amar, A.C.
75:02F-009
75:02F-030
Amoozegar-Fard, A.
75:05B-027
Anderson, J.E.
75:020-003
Anderson, R.L.
75:03F-069
Andre, J.P.
75:02G-098
Appelt, H.
75:026-081
75:02G-099
75:056-033
Araveeporn, R.
75:086-006
Arbabi, M.
75:05G-024
Ardakani, M.S.
75:026-003
75:026-037
75:056-012
Arulanadan, K.
75:02J-005
Arya, L.M.
75:02G-040
75:02G-041
75:026-042
Atesmen, K.M.
75:08B-004
Atkinson, R.J.
75:02K-008
Autry, 6.
75:056-046
Avotins, P.
75:05A-005
75:056-026
Aylor, 0.E.
75:020-004
Baker, D.R.
75:026-008
6aker, J.L.
75:056-039
ealigar, V.C.
75:026-109
Ballaux, J.C.
75:056-031
8anbury, E.E.
75:026-117
Barber, S.A.
75:021-007
Barefoot, A.D.
75:03F-032
Barfield, 6.J.
75:088-007
Barsdate, R.J.
75:056-017
Bartholic, J.F.
75:03F-035
Bassett, R.L.
75:05B-021
Batchelder, A.R.
75:050004
Batty, J.C.
75:03F-020
Bauder, J.W.
75:03F-058
Bauer, A.
75:026-036
75:026-067
75:021-004
75:03F-067
Baur, J.R.
75:026-011
8aweja, A.S.
75:026-113
Bear, J.
75:02F-021
75:02F-022
Beardsell, M.F.
75:03F-048
eeasley, R.P-
75:08B-001
8easley, S.D.
75:03F-059
Beaty, E.R.
75:03F-046
8eer, C.E.
75:02J-002
75:02J-003
75:03F-002
Behnke, J.
75:056-049
Belser, L.W.
75:026-003
75:026-037
75:026-092
75:056-012
Ben-Asher, J.
75:026-104
Bennett, O.L.
75:03F-007
203
-------
Benson, C.S.
75:02C-001
Bernstein, L.
75:030-002
75:03F-047
Bessler, M.B.
75:05G-003
Bhatnagar, V.K.
75:03F-051
Bianchi, W.C.
75:048-008
Bielorai, H.
75:02F-013
Billings, G.K.
75:02F-036
Bishop, A.A.
75:030-006
Biswas, A.K.
75:050-028
Black, C.A.
75:02G-112
75:02K-006
Blackburn, W.H.
75:020-049
Blair, B.
75:020-124
Blake, G.R.
75:02G-040
75:020-041
75:020-042
Blanchar, R.W.
75:05A-002
Blazey, D.R.
75:05G-005
Boast, C.
75:05B-028
Bohn, H.L.
75:058-032
Bosenga, S.J.
75:020-013
Bone, D.H.
75:05B-054
Boneh, A.
75:02E-003
Boone, L.V.
75:058-030
Bosmajian, G.
75:03B-004
Bouldin, D.R.
75:05A-003
Boulton, N.S.
75:048-002
Bouma, J.
75:02G-059
Bouwer, H.
75:03B-001
Bovey, R.W.
75:026-011
Bowers, S.A.
75:026-029
Boyd, C.E.
75:02H-002
Boyle, F.W.
75:02F-002
Boyle, J.R.
75:08D-001
Bradford, B.N.
75.-03F-056
Bradford, J.M.
75:02J-004
Brandt, A.
75:026-104
Branson, R.L.
75:05B-011
Bravo, N.J.
75:026-064
Brehm, R.D.
75:03F-021
75:086-003
Bremner, J.M.
75:026-089
Bresler, E.
75:020-001
75:020-002
75:026-022
75:020-023
75:020-055
75:020-119
75:03F-033
Brooks, O.L.
75:03F-049
Brooks, R.H.
75:020-026
Broughton, R.S.
75:026-063
Brown, J.
75:020-002
Brown, K.W.
75:026-108
75:026-125
Brown, R.L.
75:026-080
Browning, V.D.
75:026-066
75:021-003
Bruce, R.R.
75:02J-007
Brun, L.J.
75:030-007
Brusewitz, G.H.
75:026-008
Brustkern, R.L.
75:026-086
Brutsaert, W.
75:02D-010
75:03F-066
75:04B-012
75:05B-001
Buchanan, D.W.
75:03F-035
Bundgaard-Nielsen,M.
75:056-007
Burford, J.B.
75:08E-001
Burford, J.R.
75:026-089
Burman, R.D.
75:020-007
Burnett, E.
75:026-011
Burwell, R.E.
75:02E-004
75:05B-023
Busch, J.R.
75:03F-027
75:03F-028
Buss, G.R.
75:020-114
Butler, J.D.
75:021-001
Byara, L.
75:03F-055
Byrnes, B.H.
75:026-107
Callahan, M.W.
75:050-001
Calvert, D.V.
75:058-010
Campbell, K.L.
75:058-039
Campbell, M.D.
75:026-002
204
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Campbell, R.B.
75:021-008
75:03F-014
75:03P-030
Camper, N.D.
75:056-009
Cannell, R.Q.
75:02G-097
Carlson, R.D.
75:03F-028
Caro, J.H.
75:050-016
Carr, J.C.
75:02E-001
Carstenson, W.A.
75:02G-117
Carter, C.E.
75:05G-004
Carter, D.L.
75:02J-014
Carvallo, H.O.
75:03F-067
Cassel, O.K.
75:020-036
75:02G-046
75:02G-052
75:03F-067
Cerrillo, L.A.
75:05A-016
Chandler, R.L.
75:046-011
Chappelow, C.C.Jr.
75:056-019
Chaudhary, T.N.
75:03F-051
Chauhan, H.S.
75:02F-013
Cheng, H.H.
75:020-084
Chien, S.H.
75:02G-112
75:02K-006
Childs, S.W.
75:03C-005
Chiu, S.Y.
75:05B-057
Christensen, L.A.
75:06E-001
Chu, S.T.
75:02F-011
Chung, C.
75:058-028
Clark, R.A.
75:03F-047
Clark, R.N.
75:03F-024
Cluff, C.B.
75:06E-002
Coleman, N.T.
75:02G-010
75:020-081
75:020-099
Conrad, E.T.
75-.05E-001
Corey, A.T.
75:02G-026
Corey, F.C.
75:03F-005
Coulman, G.A.
75:02G-005
75:020-006
Cox, W.E.
75:04B-007
75:050-006
Crosson, P.R.
75:03F-041
Crow, F. R.
75:03B-003
Curtis, E.J.
75:05B-055
Dagan, 0.
75:02G-048
75:048-004
Dail, K.R.
75:05A-011
Daly, C.J.
75:048-001
Dancer, W.S.
75:03F-018
Dane, J.H.
75:020-085
Daniels, R.B.
75:05B-044
Davenport, L.A.Jr.
75:058-004
David, W.P.
75:02J-002
75:02J-003
Davidson, 8.
75:05B-038
Davidson, J.M.
75:020-008
75:05B-043
Davies, T.R.
75:058-056
Davis, S.
75:020-007
Day, A.D.
75:03F-070
Day, T.J.
75:05B-034
De Andrade, L.
75:02K-019
DeBoer, D.W.
75:02F-011
DeCook, K.J.
75:06E-002
DeCoursey, D.G.
75:02B-001
75:078-001
DeJong, J.F.
75:02J-013
Dennis, C.W.
75:020-087
Dennis, R.E.
75:03F-037
DeTar, W.R.
75:088-002
Dickerson, J.D.
75:020-024
75:02J-006
Dillon, P.J.
75:05B-019
Diner, N.
75:02G-104
Dirksen, C.
75:020-016
Diskin, M.H.
75:02E-003
Distefano, N.
75:02F-020
Dixon, R.M.
75:020-056
Dodd, D.J.R.
75:058-054
Doner, H.E.
75:020-091
75:020-092
Donnan, W.W.
75:020-004
205
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Doty, c.w.
75:021-008
75:03F-014
Dowdell, R.J.
75:02G-097
Drablos, C.J.W.
75:020-061
Drake, J.J.
75:02F-023
75:02K-003
Dreyfus, D.A.
75:03F-011
Drossos, M.E.
75:02J-009
Duckstein, L.
75:02F-010
Duffy, J.
75:058-028
Dunlap, W.J.
75:05B-051
Durrant, K.
75:058-055
Dusek, D.A.
75:03F-003
75:03F-008
75:03F-012
Dutc-her, L. C.
75:02F-034
Dylla, A.S.
75:03F-025
Dzienia, S.
75:020-038
75:02K-018
Easter, K.W.
75:03F-068
Eck, H.V.
75:020-116
Edens, C.D.
75:078-001
Edling, R.J.
75:088-007
Edmond, C.W.
75:03F-037
El-Swaify, S.A.
75:020-120
Elkan, O.K.
75:05A-011
Ellis, B.C.
75:020-005
Ellis, R.Jr.
75:03F-062
Elwell, H.A.
75:04A-003
Elzeftawy, A.
75:02G-057
Elzinga, J.
75:050-024
Emerson, W.W.
75:020-120
Enfield, C.G.
75:058-024
England, C.B.
75:040-001
Engman, E.T.
75:08E-001
Everardo, N.
75:03C-004
Falayi, 0.
75:020-059
Fangmeir, D.D.
75:05C-005
Farrell, D.A.
75:020-040
75:020-041
75:020-042
Feddes, R.A.
75:020-022
75:020-023
Feigenbaum, S.
75:02K-014
Fenn, L.B.
75:020-082
Ferrar, T.A.
75:050-014
Finley, W.W.
75:03F-024
Fischbach, P.E.
75:03F-073
Fischer, D.W.
75:050-026
Fisher, H.D.
75:020-029
Fitzsimmons, D.W.
75:03F-027
75:03F-028
Floyd, M.
75:05A-015
Fok, Y-S
75:020-033
Forrester, R.I.
75:03F-019
Foster, G.R.
75:02J-010
Foster, I.D.L.
75:05A-014
Fox, S.D.
75:03F-022
Framji, K.K.
75:05G-015
Francis, C.W.
75:05A-004
75:050-001
Francois, L.E.
75.-03C-002
75:03F-047
Frank, K.D.
75:03F-006
Franklin, M.
75:058-028
Freeze, R.A.
75:02F-016
Freney, J.R.
75:020-090
Frere, M.H.
75:058-003
75:05G-016
Friborg, N.
75:050-007
Frost, C.E.
75:058-050
Fryberger, J.S.
75:05C-007
Fuller, W.H.
75:058-027
Gairon, S.
75:020-047
Gamble, E.G.
75:058-044
Gambrell, R.P-
75.-02G-126
75:058-060
Gardiner, J.
75:050-021
Gebhard, G. Jr.
75:048-012
Geist, J.M.
75:02G-034
Geldreich, E.E.
75:05A-013
Ghate, S.R.
75:02G-062
206
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Ghildyal, B.P.
75:021-011
Ghuman, B. S.
75:02G-015
Giddens, J.
75:02K-012
Gilfilian, R.E.
75:02C-001
Gill, A.C.
75:02J-017
Gill, M.A.
75:04B-006
Gilliam, J.W.
75:02G-126
75:05B-044
75:058-060
Gitlin, H.M.
75:086-009
Click, A.N.
75:06G-002
Glover, R.E.
75:04A-010
Gluck, W.R.
75:04A-002
Golan, A.
75:02E-003
Goldberg, D.
75:026-104
Goldstein, R.A.
75:020-011
Gomez, S.P.
75:026-102
Goodwin, C.
75:020002
6orbet, D.W.
75:03F-045
Grant, K.E.
75:02J-015
Grant, L.O.
75:03B-005
6rass, L.B.
75:026-069
Gray, W.G.
75:05B-018
Greco, F.
75:04A-009
Greer, J.D.
75:03F-013
6reiner, W.H.
75:02J-016
Gumbs, F.A.
75:02G-027
75:03F-055
Gupta, S.K.
75:05B-005
Gureghian, A.B.
75:02G-073
Gurley, G.E.
75:03F-013
Haan, C.T.
75:08B-007
Hadas, A.
75:03F-061
Hagan, R.M.
75:03F-004
Hage, K.D.
75:020-005
Hagen, L.J.
75:02J-006
Hagood, M.
75:03F-079
Hague, I.
75:026-111
Haimes, Y.Y.
75:07C-001
Hall, W.D.
75:02F-026
Hamad, S. N.
75:03F-001
75:03F-020
75:03F-072
Hamdan, A.S.
75:04A-004
75:04B-005
Hanks, R.J.
75:030005
75:03F-058
Hansen, E.A.
75:026-020
Hanway, J.J.
75:026-035
75:026-105
75:05B-039
Hareleman, D.R.F.
75:05B-029
Hargrove, R.S.
75:026-121
Harman, M.M.
75:05B-055
Harmon, R.S.
75:02K-003
Harmsen, K.
75:02G-122
Harper, L.A.
75:02J-007
Harr, R.D.
75:04B-013
Harris, A.R.
75:026-020
Hart, W.E.
75:03F-029
Haubold, R.G.
75:02F-031
Haun, J.R.
75:021-006
Hauser, V.L.
75:02A-001
Hawkins, 6.W.
75:026-114
75:03F-063
Hazard, J.W.
75:026-034
Heady, E.0.
75:02F-032
75:056-008
Hedlund, J.D.
75:03F-026
Heermann, D.F.
75:03F-010
75:03F-081
Hefez, E.
75:02F-021
75:02F-022
Heil, R.D.
75:058-014
Heilman, P-
75:02K-017
Heinemann, H.6.
75:02J-011
Helweg, O.J.
75:048-015
Henderson, D.W.
75:05B-005
Hergert, 6.W.
75-.05A-003
Hess, J.W.
75:02K-003
Hildreth, D.M.
75:05B-050
207
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Hiler, E.A.
75:02A-001
75:02G-001
75:030-001
75:03F-015
75:03F-023
75:03F-057
75:03F-071
Hill, D.M.
75:060-001
Hillel, D.I.
75:02G-060
75:038-002
Hines, W.G.
75:05A-008
Hipson, N.E.
75.-05E-001
Hobson, S.
75:05B-046
Hochberg, M.
75:02K-015
Hodgdon, A.
75:026-053
75:020-106
Hoffman, D.L.
75:058-042
Hoffman, G.J.
75:030-003
Holbo, H.R.
75:048-013
Holt, R.F.
75:058-023
Holtzclaw, K.M.
75:058-033
75:078-002
Hopmans, P.A.M.
75:021-013
Horn, G.C.
75:03F-050
Horton, M.L.
75:02G-075
Horvath, E.
75:05A-011
Howell, T.A.
75:030-001
75:03F-015
75.-03F-023
75:03F-071
Hsu, P.H.
75:05F-001
Huang, P.M.
75:02G-039
Huang, W.
75:03F-009
Huck, M.G.
75:02G-066
75:021-003
Hughes, M.W.
75:02F-025
Hughes, T.D.
75:021-001
75:02K-010
Hummadi, K.B.
75:050-005
Humpherys, A. S.
75:03F-078
75:04A-005
Hunter, A.H.
75:03F-060
Hunter, J.V.
75:058-048
Hutcheson, T.B.Jr.
75:03F-063
Hyde, J.D.
75:048-013
Incropera, F.P-
75:021-002
Iqbal, M.
75:058-005
Jackson, D.R.
75:058-014
Jackson, M.L.
75:02G-100
Jackson, R.D.
75:02G-025
Jackson, W.A.
75:058-050
Jacobsen, O.S.
75:02J-019
Jaiswal, C.S.
75:02F-013
James, D.W.
75:02K-016
75:03F-058
75:03F-060
Jardine, G.D.
75:03F-022
Javendel, I.
75:048-003
Jenne, E.A.
75:05A-005
75:028-026
Jensen, M.E.
75:028-007
75.-03F-036
Jewell, W.J.
75:040-001
Johnson, A.H.
75:05A-003
Johnson, H.P-
75:058-039
Johnson, J.W.
75:02K-020
Jones, B.A.Jr.
75:058-004
Jones, D.C.
75:058-058
Jones, G.D.
75:03F-063
75:03F-064
Jones, J.B.
75:03F-046
Jorgensen, S.E.
75:02J-019
75:05E-002
Jurinak, J.J.
75:02K-007
Jury, W.A.
75:03F-054
75:058-036
75:058-037
Kaddah, M.T.
75:030-009
Kafkafi, U.
75:03F-061
Karmeli, D.
75:03F-038
Kashef, A-A.I.
75:02F-038
75:02L-001
Keller, J.
75:03F-020
75:03F-038
Kelling, K.A.
75:058-022
Kemper, W.D.
75:02G-053
75:026-106
75:056-009
Kerr, E.D.
75:058-061
Kerr, J.P.
75:03F-048
208
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Khasawneh, P.E.
75:021-009
Langrauir, D.
75:02K-004
Lundberg, K.R.
75:050-013
King, L.G.
75:020-004
King, T.G.
75:020-110
Kinniburgh, D.G.
75:020-100
Kirchner, W.B.
75:056-018
Kissel, D.E.
75:020-082
Klein, D.A.
75:050003
Klotz, D.
75:048-014
Knox, H.T.
75:05B-041
Kostrinsky, M.
75:03F-044
Krause, K.S.
75:050-001
Kreith, F.
75:020-003
Kreitler, C.W.
75:05B-058
Kroszynski, U.I.
75:046-004
Kudo, A.
75:050-006
Kurtz, L.T.
75:02K-020
75:056-030
Laag, A.E.
75:020-009
Labadie, J.W.
75:02F-001
Lagerwerff, J-V.
75:050-009
Lahav, N.
75:02K-015
Lakshman, 0.
75:05A-006
Lambert, J.R.
75:020-065
75:020-110
Lance, J.C.
75:020-043
Landon, R.A.
75:050-004
Larsen, D.P.
75:050002
Larson, W.E.
75:02E-004
Lavkulich, L.M.
75:020-019
75:02K-001
Lechner, J.F.
75:050-022
Lees, S.J.
75:020-045
75:020-076
Legg, J.O.
75:03F-034
Lehman, W.F.
75:030009
Lembke, W.D.
75:020-002
75:056-004
Leonard, R.A.
75:02J-007
Letey, J.
75:020-018
Lewis, G.C.
75:03F-027
75:03F-028
Lewis, G.L.
75:06A-001
Lianf, T.
75:03F-009
Ligon, J.T.
75:02G-065
Lindsay, W.L.
75:020-118
75:056-014
Linebarger, R.S.
75:020-043
Loch, J.P.G.
75:020-119
Loken, Jan-Per
75:020-092
Lomen, D.0.
75:020-072
Lotspeich, F.6.
75:056-006
Luebs, R.E.
75:02D-009
Lund, L.J.
75:02K-005
Lundberg, P.E.
75:03F-007
Luthin, J.N.
75:02F-018
Lutz, J.A.Jr.
75:020-114
75:03G-063
75:03F-064
Lutz, J.F.
75:020-111
Luxmoore, R.J.
75:020-011
L'Vovich, A.I.
75:050-017
Lyles, L.
75:02J-006
McCalla, T.M.
75:058-041
McCarl, B.
75:02K-009
McCool, O.K.
75:050-012
McCreery, R.A.
75:03F-046
McCuen, R.H.
75:04A-002
McElroy, A.D.
75:056-057
McGregor, K.C.
75:03F-013
McGuire, B.
75:056-046
McHenry, J.R.
75:02J-017
Mcllhenny, R.C.
75:02G-093
McKenzie, S.W.
75:052-008
McLaren, A.D.
75:020-003
75:020-037
75:056-012
McLean, E.G.
75:02G-113
75:02G-123
McNabb, J.F.
75:056-051
McNeal, 6.L.
75:02G-084
209
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McVea, C.
75:02H-002
McWhorter, D.B.
75:046-011
Haas, E.V.
75:030-003
Madding, R.P.
75:058-045
Maddock, T. Ill
75:070001
Maier, C.R.
75:058-061
Maletic, J.T.
75:05G-003
Malo, D.D.
75:020-052
Malone, C.D.
75:05A-004
Malueg, K.W.
75:050-002
Malzer, G.L.
75:021-007
Manges, H.L.
75:05A-010
Mankin, J.B.
75:020-011
Mansell, R.S.
75:020-057
Marais, J.N.
75:03F-052
Marei, S.M.
75:02F-015
Marelli, H.J.
75:02J-013
Marmer, G.J.
75:058-045
Martinec, J.
75:02F-006
Mathers, A.C.
75:020-124
Mathias, E.L.
75:03F-007
Matzdorf, K.D.
75:02G-052
Mazur, A.R.
75:02K-010
Meehan, W.R.
75:058-006
Meek, B.D.
75:030-009
Mehuys, G.R.
75:020-018
75:030-004
75:05C-008
Meints, V.W.
75:058-030
Melville, G.E.
75:020-090
Menzel, E.G.
75:02A-002
Mercado, A.
75:02F-036
Mercier, H.T.
75:050002
Meredith, D.D.
75:04A-004
75:048-005
Merkle, M.G.
75:020-011
Mertes, J.D.
75:06G-002
Meyer,- L.D.
75:02J-010
75:02J-013
Miles, D.L.
75:020-009
Miller, D.E.
75:02G-054
Miller, D.W.
75:05A-016
Miller, E.E.
75:020-012
Miller, G.A.
75:020-044
Miller, G.E.
75:020-029
Miller, R.D.
75:02G-119
Minton, N.A.
75:03F-049
Misra, M.K.
75:088-001
Misra, R.D.
75:03F-004
Mitchell, A.L.Jr.
75:038-003
Miyamoto, S.
75:03F-017
75:03F-042
75:058-032
75:05G-023
Moldenhauer, W.C.
75:02E-002
Monke, E.J.
75:02J-013
Morel-Seytoux, H.J.
75:02A-003
75:02F-033
75:02G-086
75:048-001
Mortimer, D.C.
75:05C-006
Mualem, Y.
75:02G-048
Mueller, E.W.
75:058-006
Mulder, D.
75:020-007
Mulliner, H.R.
75:03F-006
Munn, D.A.
75:020-123
Musick, J.T.
75:03F-003
75:03F-008
75:03F-012
75:04A-007
Myers, R.J.K.
75:020-094
Nagadevara, V.S.S.V.
75:02F-032
Nakayama, F. S.
75:021-012
Nash, P.A.
75:020-009
Nash, V.E.
75:020-109
Naylor, D.V.
75:03F-027
75:03F-028
Nebgen, J.W.
75:048-057
Neghassi, H.M.
75:03F-010
Nelson, D.W.
75:03K-002
75:058-025
Nelson, I.D.
75:03F-005
Nelson, S.O.
75:03F-016
Neptune, A.M.L.
75:020-105
210
-------
Neuman, S.P-
75:02F-003
75:02G-022
75:02G-023
New, L.L.
75:04A-007
Nicholson, H.P-
75:058-007
Sicol, K.J.
75:050-008
Nielsen, D.R.
75:021-012
Nielsen, K.S.
75:05G-007
Nightingale, H.I.
75:04B-008
75:04B-010
Nikolov, S.
75:02J-010
Nixon, C.C.
75-.05A-010
Nolte, B.H.
75:03F-021
75:08A-001
Northup, M.L.
75:080-001
Novak, L.T.
75:02G-005
75:02G-006
75:05B-013
Nutbrown, D.A.
75:02P-007
75:02F-024
Obrigewitsch, R.P.
75:021-012
O'Connor, G.A.
75:02G-102
O'Connor, P.W.
75:05G-025
Olness, A.
75:02A-002
Olsen, J.
75:026-053
75:026-106
Olsen, R.A.
75:02K-011
Olsen, R.A.
75:03F-053
Onken, A.B.
75:02G-121
Onstad, C.A.
75:02E-002
75:02J-001
Orhun, A.
75:02F-018
Osgood, J.O.
75:050-002
Oster, J.Di
75:058-011
75:058-015
Osterkamp, T.E.
75:02C-001
Outcalt, S.I.
75:02C-002
Page, A.L.
75:02K-005
Panattoni, L.
75:04A-009
Papendick, R.I.
75:056-012
Parfitt, R.L.
75:02K-008
Parker, M.B.
75:03F-049
Parlange, J-Y.
75:020-004
75:026-014
75:026-028
75:026-030
75:026-058
Parnas, H.
75:026-096
Patel, P.M.
75:03C-008
Patrick, W.H.Jr.
75:026-093
75:026-095
Peaslee, D.E.
75:050-031
Peled, A.
75:03F-061
Perry, C.E.
75:03F-049
Perry, L.J.Jr.
75:03F-053
Peterson, A.E.
75:05B-022
Peterson, L.R.
75:02F-034
Petryk, S.
75:038-004
Pettyjohn, W.A.
75:05B-047
Phene, C.J.
75:03F-030
Philip, J.R.
75:026-050
75:026-068
75:03F-019
Phung, H.T.
75:03F-035
Piest, R.F.
75:02E-004
75:02J-004
Pinder, 6.F.
75:058-018
Ping, C.L.
75:026-084
Poland, J.F.
75:058-035
Pratt, P.F.
75:026-010
75:026-081
75:026-099
75:02K-019
75:058-011
75:058-033
75:078-002
Pretorius, W.A.
75:058-056
Prihar, S.S.
75:026-015
75:03F-051
Pruitt, W.O.
75:03F-004
Quek, A.F.
75:058-005
Raats, P.A.C.
75:02F-037
75:021-005
Rai, 0.
75:026-118
Rakov, K.
75:026-116
Raphael, D.
75:02K-009
Rasnake, M.
75:026-071
Rath, A.
75:02F-020
Rausch, D.L.
75:02J-011
Rauschkolb, R.S.
75:058-042
Ravelo, C.J.
75:03F-023
211
-------
Rawlins, S.L.
75:030003
Reddel, D.L.
75:02G-001
75:03F-015
Reddy, G.B.
75:02K-012
Reddy, K.R.
75:020-095
Reeves, M.
75:02G-012
Reginato, R.J.
75:02G-025
Rehm, G.W.
75:03F-065
Reicosky, D.C.
75:021-008
75:03F-014
Reid, I.
75:02G-103
Reid, J.D.
75:036-005
Replogle, J.A.
75:04A-006
Reuss, J.O.
75:02K-013
Rhoades, E.D.
75:02A-002
Rhoades, J.D.
75:05B-OH
75:05B-015
Rhoads, F.M.
75:03F-045
Rible, J.M.
75:078-002
Rice, C.E.
75:08B-006
Rice, R.C.
75:020-006
Richardson, C.
75:020-011
Rickert, D.A.
75:05A-008
Riecken, F.F.
75:02G-044
Riego, D.
75:05A-002
Ritchie, J.C.
75:02J-017
Robbins, C.W.
75:02J-014
75:03F-037
Roberts, S.
75:03F-060
Robinson, F.E.
75:030-009
Roche, M-A.
75:02H-001
Rogers, R.L.
75:05B-059
Rolston, D.E.
75:021-012
75:056-042
Ross, R.
75:03F-076
75-.03F-085
Roster, G.R.
75:02J-001
Roux, P-
75:02F-029
Royer, J.M.
75:020-021
Rubin, H.
75:02F-005
Russo, D.
75:03F-033
Rust, R.H.
75:05B-040
Ryan, J.
75:03F-017
75:03F-042
Safar, M.M.
75:02F-038
Sagar, B.
75:02F-010
Sakai, W.S.
75:020-017
Sakkas, J.G.
75:088-003
Sands, M.B.
75:02J-018
Sanks, G.D.
75:021-001
Santillan-Medrano, J.
75:02K-007
Sassone, P.G.
75:05G-014
Saxton, K.E.
75:056-041
75.-02K-019
Scherer, C.R.
75:058-020
Schiele, L.H.
75:020-067
75:021-004
Schimmelpfennig, H.
75:02G-024
Schleicher, G.
75:03F-075
75:03F-080
Schmidt, K.D.
75:056-016
75:05C-001
Schneider, A.D.
75-.04A-007
Schults, D.W.
75:050-002
Schuman, G.E.
75:02E-004
75:058-041
Schuster, J.C.
75:02J-008
Schwab, G.0.
75:020-004
75:020-061
75:020-064
75:03F-021
75:080-003
Schwartz, F.W.
75:056-053
Schwartz, H.F.
75:058-061
Scott, H.D.
75:03F-059
Seely, E.H.
75:028-001
Seginer, "L.
75:03F-044
Segol, G.
75:058-018
Seifert, W.J. Jr.
75:03C-001
Sietz, W.D.
75:02J-018
Sekerka, I.
75:05G-022
Selim, H.M.
75:02F-012
75:02G-032
212
-------
Selim, M.S.
75:020-032
Seyers, J.K.
75:050-025
Shaffer, M.J.
75:02G-102
Shah, D.B.
75:020-005
75:02G-006
Shainberg, I.
75:02K-014
Shamir, U.
75:02F-021
75:02G-022
Shanholtz, V.O.
75:02E-001
75:02G-071
75:08E-001
Shearer, G.
75:03F-034
Shepherd, W.
75:020-012
Shew, D.C.
75:058-024
Skaggs, R.W.
75:02G-062
75:02G-070
75:04B-009
75:05B-044
Skidmore, E.L.
75:02G-024
75:02G-117
Skogerboe, G.V.
75:02G-009
75:050-010
75:060-001
Smajstria, A.G.
75:02G-001
Smart, R.St.C.
75:02K-008
Smika, D.E.'
75:03F-010
Smith, D.F.
75:06G-001
Smith, J.C.
75:02L-001
Smith, S.J.
75:02A-002
75:020-029
Stacey, R.L.
75:04A-005
Stafford, E.
75:02K-009
Stanford, 0.
75:02G-038
75:02K-018
75:03F-007
Starr, J.L.
75:020-058
Steadman, J.R.
75:05B-061
Steenberg, K.
75:020-115
Stegman, E.G.
75:020-067
75:021-004
Stevens, R.G.
75:02K-013
Stewart, B.A.
75:020-124
75:05G-016
Stewart, G.L.
75:05B-035
Shievely, J.M.
75:05B-009
Smith, S.W.
75:03F-039
Stewart, J.I.
75:03F-004
Shih, C.S.
75:05B-002
Shimshi, D.
75:020-001
75:020-002
Shockley, P.A.
75:03F-043
Shull, H.
75:03F-025
Shuman, F.L.Jr.
75:020-109
Shuman, L.M.
75:020-083
Shupe, O.K.
75:080-002
Signer, D.C.
75:050-011
Singer, M.J.
75:058-040
Singer, P.C.
75:02F-027
Singh, B.R.
75:020-115
Smolen, M.D.
75:020-071
Snyder, W.M.
75:02J-007
Sokol, R.A.
75:050-003
Sommerfeldt, T.G.
75:080-001
Sommers, L.E.
75:02K-002
75:05A-015
Southwick, E.M.
75:058-059
Spencer, J.R.
75:020-007
Spitze, R.G.F.
75:02J-018
Splinter, W.E.
75:03F-082
75:04A-011
Sposito, 0.
75:05A-003
75:02G-101
Spotts, J.W.
75:020-108
Stetson, L.E.
75:03F-005
75:03F-016
Stiff, M.J.
75:050-021
Stocking, M.A.
75:04A-003
Stollar, R.L.
75:02F-029
Stolzy, L.H.
75:02G-018
75:030-004
75:050008
Stone, L.R.
75:02G-075
Strateener, 0.
75:020-001
Streltsova, T.D.
75:04B-002
Stringham, G.E.
75:03F-001
75:03F-072
Stroehlein, J.L.
75:03F-017
75:03F-042
75:05g-023
213
-------
Suarez-Hernandez, A.
75:02G-035
Subbarao, Y.V.
75:03F-062
Swank, W.T.
75:020-011
Swartzendruber, D.
75:02G-047
75:038-002
Swift, L.W.
75:020-011
Syers, J.K.
75:02G-100
Tabatabai, M.A.
75:02G-105
Talpaz, H.
75:02G-060
Tan, K.H.
75:03F-046
Tanji, K.K.
75:05B-005
Tanner, C.B.
75:03F-054
Taori, A.
75:020-003
Towner, G.D.
75:02F-015
Trafford, B.D.
75:026-087
Train, R.E.
75:03F-040
Trihey, P-T.
75:05G-013
Tsuji, G.Y.
75:020-017
Tu, C.K-W.
75:026-063
Tuamsangiem, K.
75:026-078
Tucker, T.C.
75:05C-005
Tullock, R.J.
75:026-010
Turk, L.J.
75:02F-026
75:02F-035
Turner, N.C.
75:026-028
Unger, P.W.
75:026-051
Verma, S.M.
75:026-015
Viessman, N.J-
75:06A-001
Viessman, W. Jr.
75:06A-001
Visvalingam, M.
75:026-074
Volk, 6.M.
75:03F-050
Volker, R.E.
75:04A-001
Volz, M.6.
75:026-003
75:026-092
75:05B-012
Wales, R.
75:056-022
Walker, W.H.
75:05E-003
Walker, W.R.
75:03F-039
75:048-007
75:056-006
75:056-010
75:056-018
75:060001
The Task Committee
on urban sedimenta-
tion problems of
the committee on
sedimentation of
the hydraulics di-
vision
75:05A-001
Unhanand, K.
75:026-078
Vachaud, 6.
75:026-021
Vallderuten, R.
75:026-095
Wallace, A.
75:030008
Wallihan, E.F.
75:030008
Walling, D.E.
75:05A-014
Taylor, 6.S.
75:02F-018
Terman, G.L.
75:03F-056
Terry, R.E.
75:058-025
Thompson, L.F.
75:03F-059
Thompson, R.K.
75:03F-070
Timmons, D.R.
75:058-023
Todorovic P.
75:02F-004
75:02J-012
Tokar, J.V.
75:058-045
Tomar, V.S.
75:021-011
van Bavel, C.H.M.
75:026-060
van Breemen, N.
75:026-122
van Cleemput, 0.
75:026-093
van der Leeden, F.
75:05A-016
Van Doorne, W.
75:026-079
van 6enuchten, M.T.
75:02F-002
75:026-046
Vandegrift, A.E.
75:058-057
Vanden Berg, A.
75:02F-019
Vander Pol, R.A.
75:026-038
75:02K-018
Walmsley, M.E.
75:026-019
75:02K-001
Walter, N.F.
75:026-044
Warkentin, B.P.
75:026-027
Warrick, A.W.
75:026-072
75:058-027
Watanabe, R.T.
75:026-017
Watkins, R.K.
75:086-002
Watson, K.K.
75:026-025
75:026-045
75:026-076
Watts, D.6.
75:03F-005
214
-------
Weaver, W.H.
75:02K-016
75:03F-060
Weed, S.B.
75:02G-126
75:056-060
Weeks, L.V.
75:02G-018
Weisbrod, M.
75:020-002
Weisman, R.N.
75:020-008
Welch, L.F.
75:02K-020
Weller, G.
75:02C-002
Wells, B.R.
75:03F-043
Wells, D.M.
75:06G-002
Wells, L.G.
75:02G-062
Wendt, C.W.
75:02G-121
Whipple, W.Jr.
75:05B-048
Whisler, F.D.
75:02G-043
White, W.B.
75:02K-003
Whittemore, D.O.
75:02K-004
Wier, D.R.
75:02G-112
Wierenga, P.J.
75:02F-002
75:02G-046
75:02G-085
75:02G-102
Willetts, B.B.
75:02J-009
Williams, C.H.
75:02G-090
Williams, J.R.
75:05A-009
Willis, C.J.
75:05A-011
Willis, G.H.
75:05B-059
Wilmoth, B.M.
75:05B-052
Wilson, D.L.
75:03F-084
Wind, G.P.
75:02G-079
Wischmeier, W.H.
75:05G-016
Wood, A.L.
75:05B-043
Wood, F.O.
75:03F-012
Wood, W.W.
75:05B-021
75:05G-011
Woolhiser, D.A.
75:05B-008
75:056-016
Worcester, B.K.
75:02G-052
75:030-007
Worstell, R.V.
75:03F-031
Wright, J.L.
75:020-007
Wu, I-P.
75:03F-009
75:08B-005
75:08B-009
Yazar, 0.
75:05B-009
Yee, M.S.
75:058-032
Yeh, W.W-G.
75:02F-014
75:02F-017
Yih, S-M.
75:05B-038
Yomtovain, I.
75:06A-001
Yoo, K.H.
75:03F-027
Yoon, Y.S.
75:02F-017
Young, R.E.
75:02G-066
75:021-003
Youngner, V.B.
75:021-010
Youngs, E.G.
75:02G-073
75:02G-088
Yu, S.L.
75:058-048
Zaghi, N.
75:048-003
Zilli, W.B.
75:02F-027
Wiersma, 0.
75:03F-052
Wyatt, G.M.
75:02J-004
Wiese, R.A.
75:03F-065
Yahia, T.A.
75:05G-023
Wigley, T.M.L.
75:02F-008
75:02F-023
Wilke, O.C.
75:02G-121
75:03F-057
Willardson, L.S.
75:02G-007
75:08G-002
Yakowitz, S.
75:02F-010
Yare, B.S.
75:02F-028
Yaron, 0.
75:020-001
75:020-002
215
-------
Section XXXIX
SUBJECT INDEX
Absorption
75:02G-014
75:02G-016
75:02G-022
75:02G-023
75:02G-029
75:02G-030
Acids
75:02G-112
75:03F-017
75:03F-037
75:03F-042
75:056-023
Administration
75:05G-002
75:06E-002
75:070-001
Adsorption
75:026-081
75:02G-099
75:02G-100
75:02K-016
75:03F-059
75:05B-013
75:05B-043
75:05G-011
Advection
75:020-013
75:03F-054
Aeration
75:02G-053
75:02G-069
75:030-004
Aerobic
75:02J-019
Aerobic Bacteria
75:05A-011
Aerobic Conditions
75:026-095
Africa
75:04A-003
Aggregates
75:026-027
Agricultural Chemicals
75:058-049
Agricultural Engineering
75:03F-001
Agricultural Runoff
75:02A-001
75:026-060
75:04A-003
Agricultural Runoff
(cont.)
75:05A-006
75:05B-003
Agricultural Watersheds
75:02A-002
75:05A-009
75:05B-007
75:05B-011
75:05B-041
Agriculture
75:02A-001
75:020-001
75:020-002
75:02E-004
75:026-004
75:026-030
75:02G-031
75:02J-015
75:03C-003
75:03C-004
75:03C-006
75:03C-008
75:03F-005
75:03F-011
75:03F-012
75:03F-020
75:03F-029
75:03F-035
75:03F-040
75:03F-041
75:03F-048
75:04C-001
75:05B-010
75:05B-012
75:05B-014
75:05B-023
75:058-024
75:05B-039
75:05B-041
75:05B-057
75:05E-002
75:056-008
75:056-013
75:056-016
75:056-017
57:056-018
75:056-019
75:06E-001
75:066-001
Agronomy
75:026-030
75:026-031
75:026-052
Air-earth Interfaces
75:026-022
75:026-056
Air Entrainment
75:026-053
Air Pollution
75:03C-003
Air Temperature
75:048-010
Aircraft
75:05B-045
Alaska
75:02C-001
75:02C-002
75:05B-006
75:05B-017
Alcohols
75:03B-003
Alfalfa
75:026-114
75:026-124
75:03C-003
75:03C-007
75:03F-037
75:03F-047
75:05B-014
75:05B-015
Algae
75:02K-012
75:05C-004
Algorithms
75:056-007
Alkaline Soils
75:056-023
Alluvial Aquifers
75:04B-001
75:048-008
Alpine
75:026-019
75:02K-001
Alternative Planning
75:06A-001
Alternative Water
Use
75:06E-002
Aluminum
75:02G-100
75:026-114
75:026-120
75:02K-014
Ammonia
75:02F-027
75:026-032
75:02K-013
75:03F-042
75:058-049
216
-------
Ammonification
75-.02G-094
75:03F-042
Ammonium Compound
75:03F-018
Ammonium Salts
75:03F-018
75:05B-044
Anaerobic
75:02J-019
Anaerobic Bacteria
75-.05A-011
75:058-021
75:05B-056
Anaerobic Conditions
75:02G-089
75:020-095
75:058-056
Analog Models
75:02F-021
Analysis
75:02F-003
75:05A-004
75:05A-011
75:056-048
75:088-004
Analytical Techniques
75:02D-003
75:02E-001
75:02F-014
75:02F-017
75:02F-018
75:02F-037
75:02G-029
75:020-102
75:02K-002
75:05A-003
75:05A-004
75:05A-006
75:05A-012
75:058-041
75:050-009
Anion Exchange
75:050-011
Anions
75:020-045
75:020-121
Aniosotrophy
75:02F-003
75:020-017
75:020-022
75:020-023
75:04B-011
Antecedent Moisture
Content
75:020-049
75:020-103
Antitranspirants
75:020-003
Appalachian Mountain
Region
75:020-011
Application Equipment
75:038-003
Application Methods
75:03C-002
Approximation Method
75:048-004
Aquatic Environment
75:058-059
75:05C-006
Aquatic Life
75:02H-002
75:058-059
75:05C-006
Aquatic Plants
75:05C-006
Aquatic Soils
75:05C-006
Aquatic Weeds
75:02H-002
Aquicludes
75:02F-013
75:02F-015
75:048-002
75:058-044
Aquifer Character-
istics
75:02A-003
75:02F-001
75:02F-003
75:02F-010
75:02F-014
75:02F-016
75:02F-019
75:02F-020
75:02F-023
75:02F-026
75:02L-001
75:-4B-004
75:048-006
75:048-014
Aquifer Management
75:02F-038
75:048-001
75:050-004
Aquifer Systems
75:02A-003
75:02F-008
75:02F-038
75:048-012
Aquifer Testing
75:02F-003
75:02F-010
75:048-002
75:048-004
75:048-006
Aquifers
75:02A-003
75:02F-003
75:02F-005
75:02F-008
75:02F-009
75:02F-010
75:02F-012
75:02F-013
75:02F-014
75:02F-015
75:02F-016
75:02F-017
75:02F-019
75:02F-020
75:02F-021
75:02F-022
75:02F-025
75:02F-031
75:02F-035
75:02F-036
75:02L-001
75:048-006
75:048-008
75:05A-011
75:058-044
75:05C-007
Arctic
75:02C-002
75:02K-001
Arid Climates
75:04A-003
Arid Lands
75:020-002
75:020-049
75:020-069
Arizona
75:020-072
75:050-010
75:06E-002
Arkansas
75:05C-007
Arsenic Compounds
75:020-039
Artesian Aquifers
75:02F-038
75:05A-011
Artesian Heads
75:02F-021 ;
Artificial Recharge
75:048-008
75:048-010
75:058-021
75:050-011
Assessment
75:060-002
Atmosphere
75:020-010
75:020-011
75:02K-009
217
-------
Atmospheric Pressure
75:02F-035
75:02G-050
75:020-101
Attitudes
75:05G-026
Australia
75:02F-025
Automatic Control
75:03F-082
75:048-013
Automation
75:03F-082
75:04A-005
Available Water
75:02G-029
75:04B-012
Backfill
75:08G-002
75:08B-003
Bacteria
75:02G-037
75:05A-005
75:05A-011
75:058-026
75:058-054
75:05B-055
75:058-056
Bank Erosion
75:02J-003
Barley
75:020-009
75:02G-115
75:03F-063
75:03F-070
Base Flow
75:02F-024
Beans
75:03F-056
Bed Load
75:02J-008
75:02J-009
75:02J-012
Beds
75:02F-012
Behavior
75:050-014
75:05G-026
Benefits
75:06A-001
Bentonite
75:02G-047
Bermudagrass
75:020-006
75:021-010
Bicarbonates
75:02F-023
75:02K-003
75:05B-021
Bioassays
75:056-013
Biochemical Oxygen
Demand
75:058-001
75:05B-002
75:058-048
Biochemistry
75:056-049
Bogs
75:026-019
75:02K-001
Border Irrigation
75:026-056
Boron
75:02E-002
75:03F-059
Boundaries(Surfaces)
75:02F-005
75:02F-021
75:026-014
75:026-022
75:020-056
75:04B-011
Boundary Layers
75:02F-012
Boundary Processes
75:026-058
75:04A-001
Brine Disposal
75:05B-047
75:05C-007
Brines
75:058-047
Bromides
75:026-121
Bulk Density
75:026-013
75:026-017
75:02G-018
75:026-025
75:020-027
75:020-036
75:026-101
75:026-109
75:07B-002
75:080-001
Cadmium
75.-02K-007
75:056-021
Calcareous Soils
75:058-032
75:056-023
Calcite
75:02F-023
75:02K-003
Calcium
75:02G-113
75:021-007
75:02K-016
75:02K-019
75:05A-014
Calcium Carbonate
75:026-082
75:05G-023
Calcium Chloride
75:03C-002
Calibrations
75:02J-003
California
75:026-010
75:026-080
75:048-008
75:048-010
75:058-005
75:058-033
75:058-035
75:050-010
Canada
75:02G-019
75:02K-001
75:058-019
Canals
75:066-002
Canopy
75:020-001
75:020-002
75:02D-009
75:02J-010
Capillary Action
75:026-053
Capillary Conducti-
vity
75:026-053
75:048-004
Capillary Fringe
75:026-048
Capillary Water
75:026-048
75:026-086
Carbon
75:02G-038
75:026-105
75:02J-017
75:02K-012
Carbon Dioxide
75:02F-023
75:02K-003
Carbon Radioisotopes
75:02F-008
75:026-013
218
-------
Carbonate Rocks
75:02F-023
75:02K-003
Carbonates
75:02F-023
75:02F-036
75:02K-003
Cation Exchange
75:020-044
75:02G-098
75:05B-033
75:056-011
Cations
75:02H-001
Channel Flow
75:058-034
75:08B-006
Channels
75:038-001
75:058-034
Chemcontrol
75:05G-011
Chemical Analysis
75:02A-002
75:020-100
75:020-102
75:02H-001
75:05A-012
75:058-021
75:050-009
75:050-011
Chemical Potential
75:02K-004
Chemical Precipita-
tion
75.-05F-001
Chemical Properties
75:020-100
75:02K-004
75:02K-013
75:05A-014
Chemical Reactions
75:020-093
75:020-100
75:02K-004
75-.02K-005
75:02K-006
75:02K-007
75:02K-008
75:02K-009
75:02K-014
75:02K-019
75:03F-062
75:058-004
75:058-021
75:058-054
75:058-055
75:058-056
Chemical Wastes
75:058-044
75:050-023
Chemicals
75:05A-004
75:058-003
75:050-023
Chemistry
75:02F-023
75:02K-003
75:05A-011
Chemistry of Pre-
cipitation
75:058-023
Chiseling
75:03F-014
75:086-001
Chlorides
75:020-010
75:020-015
75:020-121
75:058-033
75:058-047
75:050-022
Chlorine Radioisb-
topes
75:020-046
Chromatography
75:02H-001
75:05A-011
Chromium
75:02F-028
Clay Form
75:020-029
75:058-042
Clay Minerals
75:020-019
Clays
75:020-029
75:020-030
75:020-047
75:020-083
75:020-110
Climate
75:020-007
75:02F-023
75:02K-003
Climatic Data
75:020-065
75:03C-005
Climatology
75:020-00*5
Cloud Seeding
75:02J-006
75:05C-003
Coasts
75:02L-001
75:060-002
Coastal Plains
75:058-044
Cohesive Soils
75:02J-005
Colluvium
75:020-019
Colorado
75:03F-022
75:04A-010
75:05A-016
75:058-014
75:050-009
Colorado River
75:03F-011
75:050-003
75:050-010
Colorado River
Basin
75:050-010
75:050-018
Colorado River
Compact
75:050-010
Colorimetry
75:05A-004
75:05A-012
Columns
75:020-010
Communication
75:05A-008
Competing Uses
75:06E-002
Comprehensive Plan-
ning
75:050-003
75:060-002
Compressibility
75:02F-016
Computer Models
75:02C-002
75:02E-001
75:02F-018
75:02F-021
75:02F-024
75:020-070
75:020-076
75:020-102
75:02L-001
75:048-001
75:048-012
75:058-008
75:050-003
Computer Programs
75:020-001
75:020-001
75:03F-074
75:08B-005
Computers
75:020-001
75:03F-074
75:04B-015
219
-------
Computers
(cont.)
75:05B-002
75:060-002
75:088-009
Conductivity
75:02C-001
75:020-026
75:020-027
Conduits
75:08B-001
Confined Water
75:02F-024
75:048-002
75:058-004
Conjunctive Use
75:048-001
75:048-012
Connate Water
75:058-005
Connecticut
75:020-004
Conservation
75:056-001
Consolidation
75:02F-016
Constraints
75:02P-022
75:050-003
75:050-007
75:050-008
75:06A-001
Consumptive Use
75:020-001
75:020-006
75:050-013
Contour Farming
75:058-041
Convection
75:02F-005
75:020-046
75:020-055
75:021-005
75:02J-012
75:058-018
75:058-034
Conveyance Structures
75:04A-005
Cooling Towers
75:058-020
Copper
Cores
Corn
75:02G-059
75:020-123
75:021-002
75:021-008
75:02K-020
75:03F-004
75:03F-006
75:03F-007
75:03F-014
75:03F-051
75:03F-053
75:03F-056
75:03F-062
75:03F-063
75:03F-065
75:058-028
75:058-030
75:058-041
75:058-060
Correlation Analysis
75:02F-016
75:02F-025
75:05A-014
Cost Analysis
75:08A-001
Cost-Benefit Ratio
75:048-015
Cost Comparisons
75:048-001
75:088-005
Costs
75:058-002
75:058-020
75:050-007
75:050-010
75:06A-001
75:050-021
75:020-046
75:020-057
75:020-062
Cotton
75:021-013
75:03F-059
Crop Production
75:020-009
75:020-060
75:020-117
75:020-124
75:021-008
75:021-013
75:02J-015
75:02J-018
75:02K-020
75:03C-002
75:020-009
75:020-060
75:020-117
75:020-124
75:021-008
75:021-013
75:02J-015
75:02J-018
75:02K-020
75:038-005
75:03C-002
75:03C-003
75:03C-005
75:03C-006
75:03C-007
Crop Production
(cont.)
75:03C-008
75:03C-009
75:03F-004
75:03F-010
75:03F-012
75:03F-013
75:03F-014
75:03F-041
75:03F-043
75:03F-045
75:03F-049
75:03F-050
75:03F-053
75:03F-055
75:03F-056
75:03F-058
75:03F-060
75:03F-063
75:03F-067
75:050-016
75:06E-002
Crop Response
75:020-009
75:020-063
75:020-067
75:020-077
75:020-114
75:020-115
75:020-124
75:021-001
75:021-002
75:021-004
75:021-006
75:021-008
75:021-009
75:021-010
75:021-012
75:021-013
75:02K-020
75:03C-001
75:03C-004
75:03C-005
75:03C-007
75:03C-008
75:03C-009
75:03F-003
75:03F-004
75:03F-006
75:03F-007
75:03F-008
75:03F-010
75:03F-012
75:03F-014
75:03F-022
75:03F-023
75:03F-030
75:03F-034
75:03F-038
75:03F-039
75:03F-043
75:03F-045
75:03F-046
75:03F-047
75:03F-048
75:03F-049
75:03F-050
75:03F-051
75:03F-052
75:03F-053
75:03F-055
220
-------
Crop Response
(cont.)
75:03F-056
75:03F-059
75:03F-061
75-.03F-062
75:03F-063
75:03F-064
75:03F-065
75:03F-070
75:03F-071
75:04A-008
75:05B-028
75:056-030
75:050-008
75:05G-013
75:05G-020
75:08B-008
Crops
75:020-117
75:05B-023
75:05G-008
Cultivated Lands
75:02A-002
75:02J-017
Cultivation
75:02G-051
75:026-059
75:02G-097
75:02J-002
75:02J-017
75:04A-003
75:080-001
Currents (Water)
75:02F-005
Cycles
75:020-004
75:02G-060
Darcys Law
75:02G-001
75:026-052
75:02G-075
75:04A-001
Data Collections
75:02G-056
75:04B-013
75:05A-006
75:05B-021
75:05B-035
75:05B-036
75:058-049
Data-Processing
75:020-005
Data Transmission
75:05A-006
Deciduous Forests
75:020-011
75:058-040
Decisio'n Making
75:03F-011
75:05A-008
75:058-002
Decision Making
(cont.)
75:05G-001
75:05G-026
75:05G-027
75:050-028
Decomposing Organic
matter
75:020-095
75:020-096
Deep Percolation
75:020-004
• 75:04B-009
Delaware River
75:05B-038
Deltas
75:02F-026
Denitrification
75:02G-003
75:02G-037
75:02G-038
75:020-089
75:020-093
75:020-095
75:02G-126
75:02K-018
75:05A-004
75:056-004
75:05B-025
75:058-028
75:05B-054
75:058-056
75:056-060
75:058-017
75:050-001
Density
75:048-011
Deposition (Sedi-
ments)
75:02F-026
75:02J-001
Depth
75:02F-012
75:020-050
75:020-057
75:020-075
75:021-005
Desalination
75:050-010
Dew
75:03F-048
Deserts
75:020-018
Design
75:020-056
75:03F-038
75:048-015
75:058-001
75:088-005
Design Criteria
75:04A-005
Diffusion
75:020-005
75:020-010
75:02F-004
75:02F-014
75:02F-024
75:020-014
75:020-016
75:02G-028
75:02G-030
75:020-046
75:020-055
75:020-084
75:048-014
75:056-024
Diffusivity
75:020-010
75:02F-004
75:02F-014
75:02F-037
75:020-014
75:020-016
75:020-027
75:020-031
75:020-104
75:03F-059
Digital Computers
75:04A-001
Discharge (Water)
75:02C-001
75:020-004
75:02F-006
75:02F-015
75:048-003
75:046-011
75:048-015
75:056-047
75:050-004
Dispersion
75:02E-002
75:02F-004
75:02F-005
75:02F-006
75:02F-025
75:020-001
75:020-058
75:02J-012
75:058-034
75:058-038
75:058-043
75:050-009
75:050-023
75:088-004
Dissolved Oxygen
75:03C-004
75:05A-008
75:058-001
75:056-002
75:050-024
Dissolved Solids
75:05A-012
Distribution
75:021-005
75:088-004
221
-------
Distribution Patterns
75:02F-016
75:02G-015
75:020-102
75:02J-012
75:03F-044
Distribution Systems
75:04A-005
Ditches
75:02F-015
75:02G-023
75:04B-009
Diurnal
75:020-004
75:02D-006
Dolomite
75:02F-023
75:02K-003
Drag
75:020-010
Drainage
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
:02D-011
:02F-011
: 026-002
:02G-004
:02G-007
:02G-026
:02G-057
:02G-060
:02G-061
:02G-063
:02G-064
:02G-071
:02G-078
:02G-080
:02G-085
:02G-088
:02G-126
:02I-005
:03C-005
:03F-002
:03F-021
:03F-051
:04A-001
:04B-009
:04B-015
:05B-028
:05B-060
:08A-001
:08B-001
:08B-003
:086-001
086-002
;08G-003
Drainage Design
75:02F-011
75:02G-087
Drainage Effects
75:02G-026
75:02G-102
75:02G-045
75:026-054
75:02G-063
75:02G-078
75:02G-087
Drainage Effects
(cont.)
75:02G-088
75:02G-126
75:048-009
75:05B-060
Drainage Engineering
75:02G-002
75:02G-004
75:02G-007
75:02G-062
75:02G-064
75:03F-002
75:08A-001
75:08G-001
Drainage Practices
75:02P-011
75:02G-061
75:02G-062
75:02G-063
75:02G-064
75:02G-078
75:03F-021
75:08B-001
75:08G-002
Drainage Systems
75:02G-007
75:02G-063
75:02G-073
75:02G-078
75:03F-002
75:03F-021
75:08B-001
75:08G-001
Drainage Water
75:05B-010
75:056-011
75:056-036
75-.05B-037
75:05B-059
75:08B-001
Drains
75:02F-011
75:02G-007
75:02G-062
75:026-073
75:02G-078
75:026-087
75:03F-002
75:03F-021
75:046-009
75:056-036
75:056-037
75:086-001
75:086-003
75:086-001
75:086-002
Drawdown
75:02F-003
75:02F-019
75:04B-001
75:046-002
75:04B-004
75:04B-009
75:046-015
Drilling
75:07B-002
Drilling Equip-
ment
75:07B-002
Drought Resistance
75:020-009
Dry Farming
75:03F-055
Dry Seasons
75:03F-055
Drying
75:026-027
75:02G-048
Dupuit-Forcheimer
Theory
75:02F-015
75:02F-018
75:02F-030
75:046-009
75:046-011
75:086-003
Dynamic Programming
75:026-060
75:088-005
Earth Pressure
75:026-101
Ecology
75:020-003
Economic Efficiency
75:056-020
75.-06A-001
Economic Impact
75-.03F-002
75:056-002
75:056-008
Economic Justifi-
cation
75:02F-032
Economics
75:02F-032
75:03F-002
75:046-001
75:056-014
75:056-026
Ecosystems
75:056-017
75:066-001
Eddies
75:020-010
Education
75:056-001
Efficiencies
75:03F-020
222
-------
Effluents
75:05B-002
75:05B-020
75:05B-036
75:05B-037
75:05G-007
Electric Power
75:03F-005
Electric Power Costs
75:03F-016
Electric Power De-
mand
75:03F-016
Electrical Conductance
75:02C-001
Electrodes
75:02G-043
75:02G-044
75:02G-121
75:04B-013
75:05A-004
75:05G-022
Electronic Equipment
75:02G-017
75:026-029
75:048-013
Energy
75:020-013
75:03F-005
75:03F-020
75:04C-001
Energy Budget
75:020-012
75:020-013
Energy Conservation
75:03F-080
75:03F-081
Energy Gradient
75:08B-005
Engineering
75:04C-001
Entrainment
75:04B-011
Environment
75:020-005
75:021-002
75:03F-040
75:03F-041
75:056-020
75:05G-001
75:05G-026
75:05G-028
Environmental Con-
trol
75:021-002
75:03C-004
75:03F-040
Environmental Effects
75:02G-069
75:021-002
75:03F-041
75:05A-008
75:05G-004
75:05G-009
75:06G-002
Environmental Engineer-
ing
75:05G-028
Equations
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
02A-
020-
02F-
02F-
02F-
02F-
02F-
02F-
02F-
02F-
02F-
02F-
02F-
02F-
02F-
02F-
026-
026-
026-
026-
026-
026-
026-
02G-
02G-
026-
026-
026-
026-
02J-
02L-
04A-
04B-
04B-
04B-
04B-
05B-
05B-
05G-
05G-
08B-
001
008
001
003
004
005
012
013
014
015
017
021
022
024
025
037
013
014
022
033
•046
•050
•055
•058
068
•072
•073
•101
•104
002
•001
002
002
•004
•Oil
•015
•001
•002
•007
•008
•005
Equilibrium
75:026-012
75:020-013
75:02G-101
Equipment
75:02G-047
75:02G-059
75:02G-061
75:026-107
75:04B-008
75:05A-007
Erosion
75:02E-002
75:02F-032
75:026-049
75:02J-004
75.-02J-005
75:02J-006
75:02J-007
75:02J-008
75:02J-009
75:02J-010
75:02J-013
75:02J-015
75:02J-016
75:02J-018
75:03F-013
75:05B-023
75:056-019
75:08E-001
Erosion Control
75:02J-008
75:02J-009
75:02J-010
75:02J-016
75:03F-013
Erosion Rates
75:02E-002
75:02F-023
75:02J-001
75:02J-005
75:02J-008
75:02J-009
75:02J-013
Estimating
75:020-005
75:020-013
75:026-012
75:04A-002
75:05A-004
75:05B-019
Estuaries
75:05B-038
Estuarine Environ-
ment
75:058-038
Eutrophication
75:05B-022
75:058-025
75:058-039
75:058-040
75:05C-002
75:05C-004
Evaluation
75:026-102
75:048-015
75:05A-004
75:058-035
75:058-042
75:056-003
75:056-008
75:06A-001
75:066-002
75:088-005
Evaporation
75:020-001
75:020-002
75:020-004
75:020-005
75:020-007
223
-------
Evaporation
(cont.)
75:020-008
75:020-010
75:020-012
75:020-013
75:02G-022
75:02G-055
75:02G-060
75:021-005
75:038-001
75:03B-003
75:03F-024
75:03F-032
75:03F-054
Evaporation Control
75:03B-003
Evaporation Pans
75:020-001
Evapotranspiration
75:020-001
75:020-002
75:020-006
75:020-007
75:020-009
75:020-011
75:02F-025
75:020-023
75:020-054
75:020-072
75:020-075
75:020-077
75:020-110
75:03B-001
75:030-005
75:03F-004
75:03F-028
75:03F-032
75:03F-039
75:03F-048
75:03F-054
75:03F-067
75:03F-071
75:04A-008
75:048-009
75:05B-028
75:050-020
75:08B-008
Excess Water (Soils)
75:05B-036
75:056-037
75:086-001
Expansive Clays
75:020-047
Expansive Soils
75:020-101
Exploration
75:046-008
Fallout
75:050-009
Fallowing
75:020-060
Farm Wastes
75:05A-006
75:050-013
Federal Jurisdiction
75:050-003
Feed Lots
75:04C-001
75:05A-006
75:05B-027
Fertilization
75:020-077
75:020-082
75:020-106
75:020-123
75:02J-019
75:02K-010
75:02K-012
75:02K-020
75:03C-008
75:03F-006
75:03F-007
75:03F-018
75:03F-034
75:03F-039
75:03F-042
75:03F-043
75:03F-046
75:03F-049
75:03F-050
75:03F-051
75:03F-053
75:03F-055
75:03F-056
75:03F-058
75.-03F-060
75:03F-061
75:03F-062
75:03F-063
75:03F-064
75:03F-065
75:03F-079
75:04A-008
75:05B-006
75:056-030
75:056-039
75.-05B-060
75:050-020
75:086-008
Fertilizers
75:02A-002
75:020-082
75:020-123
75:021-009
75:02K-010
75:02K-020
75:030-008
75:03F-006
75:03F-007
75:03F-018
75:03F-034
75:03F-035
75:03F-042
75:03F-043
75:03F-050
75:03F-053
75:03F-055
75:03F-058
75:03F-060
75:03F-061
Fertilizers
(cont.)
75:03F-061
75:03F-062
75:03F-063
75:03F-065
75:056-010
75:05B-022
75:058-023
75:05B-030
75:058-036
75:058-037
75:058-041
75:058-042
75:058-049
75:058-060
75:050-001
75:050-019
75:078-002
Field Capacity
75:020-001
75:020-002
75:020-049
75:020-103
75:020-104
Field Crops
75:020-023
75:038-002
Films
75:038-003
Filters
75:03F-084
Filtration
75:03F-084
Finite Element
Analysis
75:02F-017
75:02F-018
75:020-022
75:020-023
75:020-073
75:048-004
75:04B-001
75:058-018
Fish
75:02H-002
Flood Control
75:06A-001
Flood Damage
75:06A-001
Flood Flow
75:02A-003
75:02E-003
75:05A-014
Flood Irrigation
75:020-069
75:030-009
75:03F-068
Flood Peak
75:05A-014
224
-------
Flood Plains
75:03B-003
75:08B-006
Flood Routing
75:05A-014
Flooding
75:02G-053
Florida
75:02F-008
75:05A-011
Flow
75:02G-022
75:020-030
75:020-032
75:020-047
75:02J-012
75:03B-004
75:056-034
75:058-044
75-.08B-006
Flow Characteristics
75:038-004
75:05A-014
Flow Control
75:04A-005
Flow Measurement
75:020-072
75:04A-006
Flow Nets
75:02F-012
75:02F-018
75:04A-001
Flow Profiles
75:02C-001
75:02J-012
75:058-034
Flow Rates
75:02F-012
75:020-072
75:020-091
75:02J-010
75:04A-006
75:05B-020
75:058-039
Flow Resistance
75:088-006
Fluid Mechanics
75:08B-004
Flumes
75:04A-006
Fluorescence
75:05A-006
Fluorometry
75:05A-006
Foliar
75:03C-002
Food Abundance
75:04C-001
Forage Grasses
75:03F-046
75:03F-055
Forages
75:03F-046
Forecasting
75:02A-001
75:02F-021
75:02F-022
75:048-012
75:056-036
75:058-037
Forest Soils
75:058-040
Forest Watersheds
75:02D-004
Forests
75:020-004
Fourier Analysis
75:048-003
75:048-010
Frazil Ice
75:02^-001
Free Surfaces
75:02F-018
Freezing
75:02C-001
75:05A-003
Frequency Analysis
75:058-048
Freshwater
75:02C-002
Frozen Ground
75:020-119
Frozen Soils
75:02G-119
Fungicides
75:02K-010
Furrow Irrigation
75:020-106
75:03F-001
75:03F-003
75:03F-008
75:03F-014
75:03F-019
75:03F-028
75:03F-029
75:03F-072
75:03F-075
75:03F-076
75:03F-077
75:04A-012
75:04A-013
75:05C-005
Furrow Systems
75:03F-001
Geochemistry
75:02F-008
75:02F-023
75:02H-001
75:02K-003
75:02k-004
75:050-004
75:050-011
Geographical Re-
gions
75-.02K-003
Geohydrologic
Units
75:048-015
75:056-005
Geologic Investi-
gations
75:02K-005
Geologic Mapping
75:050-004
Geological Surveys
75:02K-005
Geology
75:058-005
75:05B-021
75:05G-004
Geomorphology
75:020-019
75:02K-001
Geophysics
75:048-008
Geothermal Studies
75.-03C-006
Germination
75:05C-008
Glacial Soils
75:020-052
Grain Sorghum
75:02G-075
75-.03C-008
75:03F-053
75:03F-071
Grains (Crops)
75:02G-075
75:03F-041
Graphical Methods
75:048-009
Grasses
75:020-117
75:021-001
75:02K-012
75:03F-007
75:03F-046
75:03F-055
225
-------
Grasslands
75:020-012
75:026-019
75:04A-003
Gravimetric Analysis
75:020-004
75:02G-018
Gravitational Water
75:02G-045
75:02G-068
75:02B-021
Gravity
75-.02G-027
Grazing
75.-02A-002
Great Lakes
75:020-013
75:056-045
Great Plains
75:02A-001
Groundwater
75:02E-002
75:02F-003
75:02F-004
75:02F-008
75:02F-010
75:02F-013
75:02F-014
75:02F-015
75:02F-018
75:02F-019
75:02F-020
75:02F-022
75:02F-023
75:02F-028
75:02F-029
75:02F-030
75:02F-031
75:02F-034
75:02F-035
75:02F-036
-75:02F-037
75:02F-038
75:02G-015
75:02G-073
75:02H-001
75:02K-003
75:02L-001
75:03B-001
75:030-005
75:04A-004
75:048-002
75:048-003
75:048-004
75:048-005
75:048-007
75:048-008
75:048-010
75:048-012
75:048-014
75:048-015
75:05A-013
75:05A-016
75:058-004
75:058-016
75:058-035
Groundwater
(cont.)
75:058-039
75:058-041
75:058-044
75:058-047
75:058-049
75:058-051
75:05B-052
75:058-058
75:05C-001
75:05C-007
75:05E-001
75:05E-002
75:05G-002
75:05G-011
75:088-003
Groundwater Availa-
bility
75:02F-034
Groundwater Basins
75:02E-002
75:02F-001
75:02F-009
75:02F-033
75:02F-034
75:048-012
Groundwater Move-
ment
75:02A-003
75:02F-004
75:02F-005
75:02F-006
75:02F-009
75:02F-010
75:02F-012
75:02F-013
75:02F-015
75:02F-016
75:02F-017
75:02F-018
75:02F-0«24
75:02F-025
75:02F-026
75:02G-012
75:02G-032
75:02G-052
75:02L-001
75:048-003
75:046-009
75:048-010
75:058-016
75:058-018
75:058-042
75:058-044
75:05C-001
75:05G-004
Groundwater Potential
75:02F-012
75:02G-032
75:048-003
75:048-012
Groundwater Recharge
75:02E-002
75:02F-008
75-.02F-009
75:02F-025
75:02F-030
Groundwater Re-
charge (cont.)
75:02G-060
75:048-008
75:05B-021
Groundwater Re-
sources
75:02F-029
75:02F-030
75:02F-033
75:02F-034
75:05A-013
75:05A-016
75:070-001
Growth Stages
75:020-009
Gullies
75:02J-004
Gully Erosion
75:02J-002
75:05A-009
Gypsum
Hail
75:05G-009
75:05G-023
75:02J-006
Hardwood
75:020-011
Hawaii
75:02G-017
75:03F-009
Hazen-Williams
Equation
75:08B-005
Head Loss
75:04A-001
Heat
75:02F-037
Heat Flow
75:020-005
75:020-013
Heat Transfer
75:020-010
75:02F-005
75:02F-037
75:05B-029
Heated Water
75:056-020
75:058-029
75:058-045
Heating
75:056-029
Heavy Metals
75:05E-002
Herbicides
75:02G-011
226
-------
Herbicides
(cont.)
75:03F-075
75:05B-043
75:058-059
Heterogeneity
75:02G-050
75:02G-056
Hexadecanol
75:03B-003
Hickory Trees
75:020-011
Height
75:02F-013
75:02F-015
Homogeneity
75:02F-016
75:02F-017
75:02G-001
Humidity
Humus
75:020-005
75:020-010
75:05E-002
Hybrid Computers
75:02F-021
Hydraulic Conductiv-
ity
75:020-006
75:02F-012
75:02F-016
75:02F-017
75:02G-016
75:026-018
75:026-022
75:026-023
75:02G-031
75:02G-032
75:02G-042
75:02G-047
75:02G-050
75:02G-052
75:02G-053
75:02G-054
75:026-057
75:02G-059
75:02G-075
75:02G-104
75:02L-001
75:04A-001
75:043-004
75:04B-009
75:083-003
Hydraulic Design
75:088-002
Hydraulic Gradient
75:02F-025
75:02G-023
75:026-047
Hydraulic Models
75:058-004
Hydraulic Models
(cont.)
75:088-001
Hydraulic Proper-
ties
75:02F-026
75:026-047
75:026-060
Hydraulic Radius
75:088-006
Hydraulic Valve
75.-04A-005
Hydraulics
75:02A-003
75:02F-004
75:02F-014
75:02F-019
75:02J-004
75:038-004
75:Q3F-038
75:048-002
75:048-003
75:056-001
75:05G-004
75:088-002
75:088-004
75:088-006
75:088-009
Hydrochemical Pro-
perties
75:02F-026
Hydrodynamics
75:026-050
75:026-068
Hydrogen Ion Concen-
tration
75:02C-001
75:02K-003
75:02K-004
75:058-021
75:056-011
Hydrogeology
75:02F-001
75:02F-008
75:02F-025
75:02K-003
75:058-005
75:056-002
75:056-004
Hydrograph Analysis
75:02F-006
Hydrographs
75:02E-003
75:02F-020
75:04A-009
75:05A-014
Hydrologic Aspects
75:020-004
75:02E-001
75:048-007
75:06A-001
Hydrologic Budget
75:05C-002
Hydrologic Cycle
75:02E-003
Hydrologic Data
75:02F-022
Hydrologic Proper-
ties
75:02F-036
75:04B-002
Hydrologic Systems
75:02B-001
75:02E-003
75:02F-033
75:02F-036
75:02H-001
75:058-019
Hydrology
75:02A-
75:02A-
75:028-
75:020-
75:02E-
75:02E-
75:02F-
75:02F-
75:026-
75:04A-
75:040-
75:05A-
75:05B-
75:058-
75:056-
75:08E-
•001
•003
•001
•005
•001
•002
•024
•033
•012
002
•001
•014
•005
008
Oil
001
Hydrometry
75:056-015
Hydrothermal
Studies
75:02F-037
Hysteresis
75:026-012
75:026-021
75:026-025
75:026-027
75:026-045
75:026-047
75:026-048
75:026-085
75:026-103
Ice
75:02C-001
75:026-019
Idaho
75:020-007
75:05A-016
Identifiers
75:020-002
Illite
75:02K-014
227
-------
Impact (Rainfall)
75:04A-003
Imapaired Water Quality
75:05G-010
Impervious Membranes
75:026-088
Indicators
75:05A-006
Industrial Wastes
75:05A-011
75:058-044
75:056-014
Industries
75:056-014
Infiltration
75:020-002
75:02F-006
75:026-001
75:026-009
75:026-012
75:026-014
75:026-015
75:026-022
75:026-023
75:026-027
75:026-028
75:026-030
75:026-032
75:026-033
75:026-045
75:026-049
75:026-050
75:026-052
75:026-053
75:026-054
75:026-055
75:026-056
75:026-057
75:026-059
75:026-060
75:026-068
75:026-085
75:026-086
75:026-102
75:026-103
75:026-104
75:026-116
75:02K-015
75:03B-002
75:03B-003
75:03F-033
75:04B-010
75:05B-022
75:056-042
75:05B-043
75:056-023
Infiltration Rates
75:026-009
75:026-012
75:026-028
75:026-056
75:026-068
75:026-085
75:05B-021
Infiltrometers
75:026-056
75:03B-002
75:05B-022
Infrared Radiation
75:026-024
75:05B-045
Injection Wells
75:05A-011
75:05B-047
Inorganic Compounds
75:05A-003
75:05A-004
75:05B-041
75:05B-049
Input-Output Analysis
75:02E-003
75:02P-001
Installation
75:03F-020
Institutional Con-
straints
75:056-006
75:06E-001
75:06E-002
75:066-001
Institutions
75:056-006
Instrumentation
75:026-020
75:026-021
75:026-024
75:026-025
75:026-029
75:026-056
75:026-102
75:048-013
75:05A-004
75:05A-011
75:07B-002
Interfaces
75:020-010
Interstices
75:026-053
Ion Exchange
75:02F-026
75:056-011
Ion Transport
75:026-001
75:026-046
75:05B-041
Iowa
Ions
75:026-081
75:026-099
75:026-102
75:02H-001
75:02K-003
75:05A-004
75:02A-001
75:02F-032
75:026-035
75:026-105
75:02J-001
75--02J-003
75:02J-004
75.-02J-016
75:058-039
75:058-041
Iron
75:026-100
75:026-120
75:026-122
75:02K-008
75:02K-014
75:02K-015
Iron Compounds
75:02K-004
Iron Oxides
75:02K-004
75:02K-008
Irrigated Land
75:03F-036
Irrigati
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
on
:02D-
: 02D-
:02D-
:02D-
:02F-
:026-
:026-
:026-
:026-
:026-
:026-
:026-
:026-
:026
:026'
:026'
:026'
:026'
:026-
:02I-
:02I-
:02I-
:02I-
:02I-
:02I-
:02J-
:03C-
:03C-
:03C-
:03C-
:03F-
:03F-
:03F-
:03F-
:03F-
:03F-
:03F-
:03F-
:03F-
:03F-
:03F-
:03F
001
002
006
007
025
002
009
052
053
054
066
067
072
•075
•077
•079
•092
•102
•106
•003
•004
•005
•008
Oil
•013
•014
•001
•005
•006
•008
•001
•003
•004
005
006
•008
•Oil
•012
014
015
016
-020
228
-------
Irrigation
(cont.)
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
03F-022
03F-024
03F-025
03F-026
03F-027
03F-028
03F-029
03F-031
03F-033
:03F-036
:03F-038
:03F-039
:03F-044
:03F-045
:03F-051
:03F-052
:03F-055
:03F-057
:03F-058
:03F-064
:03F-065
:03F-067
:03F-068
:03F-069
:03F-070
:03F-071
:03F-072
:03F-073
:03F-074
:03F-075
:03F-076
:03F-077
:03F-078
:03F-079
:03F-080
:03F-082
:03F-083
:03F-084
:03F-085
:04A-005
:04A-008
:04A-011
:04A-012
:04A-013
:04B-015
:05B-005
:05B-010
:05B-011
:05B-061
:05C-005
:05E-003
:05G-001
:05G-017
:05G-020
:07B-002
:08B-002
:08B-005
:08B-008
:08B-009
Irrigation Design
75:02G-077
75:03C-005
75:03F-001
75:03F-015
75:03F-029
75:03F-031
75:03F-039
75:03F-044
75:04A-005
75:04A-008
Irrigation
(cont.)
75:05G-020
75:086-005
75:088-008
75:08B-009
Irrigation Effects
75:02D-007
75:02E-004
75:02F-011
75:02G-054
75:02G-067
75:02G-069
75:02G-071
75:020-077
75:02G-102
75:02G-106
75:021-004
75:021-008
75:021-013
75:02J-014
75:030001
75:030002
75:030008
75:03F-003
75:03F-004
75:03F-005
75:03F-014
75:03F-016
75:03F-023
75:03F-024
75:03F-025
75:03F-027
75:03F-031
75:03F-033
75:03F-035
75:03F-039
75:03F-045
75:03F-052
75:03F-055
75:03F-058
75:03F-064
75:03F-067
75:03F-068
75:03F-070
75:03F-071
75:04A-007
75:04A-008
75:05B-005
75:05B-011
75:056-041
75:050005
75:05G-020
75:08B-008
Irrigation Efficiency
75:026-054
75:02G-077
75:03C-005
75:03F-015
75:03F-022
75:03F-026
75:03F-031
75:03F-036
75:03F-038
75:03F-039
75:03F-044
75:03F-057
75:03F-071
75:03F-072
75:03F-073
75:03F-076
Irrigation Effi-
ciency (cont.)
75:03F-077
75:03F-078
75:03F-082
75:03F-085
75:04A-005
75:04A-008
75:05G-020
75:086-008
Irrigation Engi-
neering
75:02G-002
75:026-009
75:02G-007
75:03F-001
75:03F-029
75:03F-039
75:04A-005
75:04A-008
75:056-020
75:088-002
75:088-008
Irrigation Methods
75:03F-083
Irrigation Opera-
tion & Mainte-
nance
75:04A-005
Irrigation Opera-
tion and Manage-
ment
75:03F-005
Irrigation Prac-
tices
75:02F-003
75:026-066
75:026-077
75:026-102
75:021-011
75:03F-003
75:03F-004
75:03F-015
75:03F-016
75:03F-022
75:03F-023
75:03F-026
75:03F-027
75:03F-028
75:03F-029
75:03F-031
75:03F-033
75:03F-038
75:03F-039
75:03F-045
75:03F-069
75:03F-071
75:03F-072
75:03F-073
75:03F-074
75:03F-075
75:03F-076
75:03F-078
75:03F-079
75:03F-082
75:03F-083
75:04A-005
75:04A-007
229
-------
Irrigation Practices
(cont.)
75:04A-008
75:04A-011
75:058-042
75:05C-005
75:05E-003
75:05G-020
75:05G-023
75:08B-008
Irrigation Systems
75:02G-053
75:02G-077
75:03C-005
75:03F-001
75:03F-016
75:03F-019
75:03F-023
75:03F-029
75:03F-031
75:03F-032
75:03F-038
75:03F-039
75:03F-057
75:03F-068
75:03F-071
75:03F-072
75:03F-073
75:03F-077
75:03F-078
75:03F-079
75:03F-084
75:04A-005
75:04A-008
75:04A-011
75:04A-012
75:05G-020
75:08B-005
75:086-008
75:08B-009
Irrigation Water
75:030-002
75:030-003
75:03F-006
75:03F-026
75:03F-029
75:03F-042
75:03F-084
75:03F-085
75:04A-007
75:05B-014
75:058-015
75:05B-061
75:05G-010
75:06E-002
75:070001
75:08B-003
Irrigation Water
Costs
75:03F-020
Isotherms
75:058-045
Isotope Fractionation
75:02F-008
Isotope Studies
75:02F-008
75:026-013
75:02H-001
Isotropy
75:02F-017
75:02G-001
75:048-011
Kansas
75:02A-001
Kaolinite
75:02G-017
75:02G-113
Kinetics
75:058-013
75:05B-024
Labor
75:02G-030
Laboratory Equipment
75:02G-109
75:058-050
75:05G-022
Laboratory Tests
75:020-003
75:02G-018
75:020-027
75:02G-031
75:02G-043
75:02G-044
75:02G-046
75:020-047
75:020-076
75:026-050
75:026-057
75:026-068
75:026-104
75:026-109
75:02K-011
75:05A-007
75:058-004
75:05B-043
75:05B-050
75:088-006
Lake Basins
75:02H-001
Lake Huron
75:020-013
Lake Michigan
75:05B-045
Lake Sediments
75:02H-001
Lakes
75:020-008
75:020-013
75:026-019
75:02H-001
75:038-003
75:05B-019
75:058-020
75:058-045
Land Classification
75:04A-002
Land Management
75:06E-001
Land Reclamation
75:03F-017
75:03F-018
75:056-009
Land Resources
75:056-008
Land Use
75:03F-020
75:04A-001
75:056-001
75:056-004
75:06E-002
Latent Heat
75:020-005
Lawns
75:020-006
Leachate
75:05B-042
75:056-009
Leaching
75;
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
026-015
026-084
026-091
026-092
020-106
021-005
02K-015
03C-001
03F-018
03F-027
03F-028
03F-035
03F-036
03F-047
03F-065
058-003
058-010
05B-015
058-017
058-036
05B-037
058-041
050-009
Lead
75:02K-007
75:050-021
Least Squares
Method
75:02F-001
75:02F-019
Leaves
75:020-003
75:030-002
75:03C-003
Legal Aspects
75:048-007
75:050-005
75:06E-002
Legislation
75:02F-032
75:02F-033
75:02J-016
75:058-036
230
-------
Lettuce
75:050-005
Lichens
Lime
75:02K-001
75:03F-059
75:05B-010
Limestones
75:02F-023
75:02K-003
Linear Programming
75-.02F-014
75:02F-022
75:02J-018
75:06A-001
Liquid Wastes
75:05A-011
Livestock
75:05G-008
75:05G-019
Loam
Loess
75:02G-055
75:02G-056
75:02G-059
75:020-075
75:05B-041
Lysimeters
75:02D-009
75:02F-006
75:02G-011
75:020-102
75:02G-125
75:030001
75.-03F-047
75:03F-071
75:058-015
Magnesium
75:02K-014
75:02K-016
75:05A-014
Management
75:02G-001
75:02F-011
75:03F-036
75:05A-008
75:056-002
75:05G-007
75:056-004
75:06A-001
75:06G-001
Mannings Equation
75:08B-006
Mapping
Maps
75:05A-008
75:05G-004
Marginal Costs
75:05B-020
Market Value
75:05G-026
Mass Transfer
75:02D-013
75:02F-004
75:05B-018
Mass Wasting
75:02J-004
Mathematical Analysis
75:021-009
75:08B-009
Mathematical Models
75:02E-001
75:02E-001
75:02F-005
75:02F-012
75:02F-020
75:02F-022
75:02F-025
75:02G-001
75:02G-006
75:02G-012
75:02G-022
75:02G-023
75:02G-032
75:02G-045
75:026-046
75:02G-048
75:02G-050
75:026-055
75:026-058
75:026-064
75:026-068
75:026-072
75:026-073
75:026-079
75:021-006
75:02J-001
75:02J-002
75:02J-003
75:02J-007
75:030-005
75:03F-033
75:04B-001
75:048-011
75:05A-008
75:05B-001
75:05B-002
75:05B-003
75:05B-018
75:05B-020
75:058-036
75:058-037
75:056-003
75:056-007
75:056-008
75:056-027
75:056-028
75:06A-001
75:060001
75:086-007
Mathematical Studies
75:02F-003
75:02F-004
75:02F-014
75:02F-017
75:02F-019
75:02F-020
75:02F-031
Mathematical
ies (cont
75:02F-
75:026-
75:026-
75:026-
75:026-
75:02G-
75:026-
75:02J-
75:03F-
75:04A-
75:04B-
75:048-
Stud-
•037
•014
•030
•032
•033
073
086
012
066
009
004
006
Mathematics
75:02E-001
75:02F-014
75:02F-024
75:026-030
75:026-104
75:03F-066
75:04A-009
75:088-004
Measurement
75:026-056
75:026-072
75:026-074
75:048-013
75:05A-004
75:05A-006
75:058-049
75:056-015
Melt Water
75:020-002
75:02F-006
Mercury
75:05A-005
75:05A-015
75:058-026
75:050-006
Meteorological Data
75:020-011
Methane
75:05A-011
Methane Bacteria
75:05A-011
Methodology
75-.02K-002
75:046-015
75:058-020
75:056-004
75:056-026
Mexican Water
Treaty
75:056-010
Mexico
75:030-004
75:056-010
Microbial Degrada-
tion
75:050-003
231
-------
Microclimatology
75:021-008
Microorganisms
75:02G-096
75:05A-011
Migration
75:05B-044
Mineralogy
75:020-019
Mining
75:05B-057
Minnesota
75:058-023
75:05B-040
75:05G-013
Mixing
75:05B-018
75:058-034
Model Studies
75:02A-003
75:020-002
75:02D-001
75:020-002
75:020-005
75:020-008
75:020-010
75:020-011
75:02E-001
75:02E-002
75:02E-003
75:02F-001
75:02F-004
75:02F-010
75:02F-013
75:02F-015
75:02F-018
75:02F-020
75:02F-021
75:02F-023
75:02F-024
75:02F-025
75:02F-030
75:02F-033
75:02F-036
75:02G-001
75:02G-002
75:02G-005
75:02G-006
75:02G-008
75:02G-009
75:02G-027
75:02G-032
75:02G-045
75:026-048
75:02G-060
75:02G-064
75:02G-065
75:02G-068
75:02G-070
75:026-071
75:02G-072
75:02G-079
75:02G-088
75:02G-096
75:026-098
75:026-102
Model Studies
(cont.)
75:026-110
75:02G-118
75:026-119
75:026-122
75:021-002
75:021-006
75:02J-001
75:02J-002
75:02J-003
75:02J-007
75:02J-019
75:02K-009
75:03F-009
75:03F-010
75:03F-015
75:03F-057
75:04A-001
75:04A-002
75:04A-004
75:04B-001
75:04B-005
75:04B-011
75:04B-012
75:040-001
75:05B-003
75:05B-004
75:05B-005
75:05B-007
75:058-008
75:05B-013
75:05B-019
75:05B-024
75:058-028
75:058-038
75:058-053
75:056-004
75:056-018
75:056-024
75:050-027
75:056-028
75:06C-001
75:08B-007
Moisture
75:020-012
75:026-021
75:026-025
75:026-029
75:021-012
Moisture Availability
75:026-021
75:026-025
75:026-029
75:026-051
Moisture Content
75:020-004
75:02F-018
75:026-001
75:026-016
75:026-021
75:026-025
75:026-026
75:026-027
75:026-028
75:026-029
75:026-045
75:02G-050
75:026-051
75:02G-052
Moisture Content
(cont.)
75:026-054
75:020-055
75:02G-057
75:026-060
75:020-101
75:020-103
75:026-104
75:05B-004
Moisture Meters
75:026-074
Moisture Stress
75:020-009
75:020-012
75:021-008
75:021-013
75:03F-052
75:03F-058
75:03F-059
75:03F-070
75:03F-071
Moisture Tension
75:026-026
75:026-045
75:026-054
75:020-109
75:020-110
75:021-008
75:03C-007
Molybdenum
75:058-014
Momentum Equation
75:02A-003
Monitoring
75:05A-006
75:058-036
75:058-049
75:05G-007
Montana
75:03C-007
75:05A-016
Monte Carlo Method
75:02F-016
75:058-001
Montmorillonite
75:026-017
Movement
75:020-004
75:02G-068
75:02J-012
75:05B-034
75:058-044
75:088-001
Mulching
75:02G-060
Multiple Purpose
Projects
75:066-002
Municipal Water
75:06E-002
232
-------
Natural Flow
75:02L-001
75:053-034
Natural Resources
75:05G-001
Nebraska
75:06A-001
Negative Pore Pressure
75:02G-026
Nematicides
75:03F-049
Nematodes
75:03F-049
Neutron Activation
Analysis
75:02G-074
Neutron Absorption
75:02G-074
Nevada
75:02G-049
New Jersey
75:02F-028
75:058-038
75:05B-048
New Mexico
75:046-012
75:056-011
New York
75:05A-003
Nitrates
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
:02A-002
:02G-003
:02G-037
:02G-046
:02G-071
:02G-091
:02G-092
:02G-095
:02G-097
:02G-124
:02K-013
:02K-017
:03F-018
:05A-004
:05B-004
:05B-010
:05B-012
:05B-025
:05B-039
:05B-041
:05B-044
:05B-049
:05B-050
:05B-054
:05B-058
;05C-005
:050-001
Nitrates
(cont.)
75:02K-010
75:02K-013
75:02K-017
75:05B-012
75:058-025
75:05B-028
75:05B-055
Nitrite Soil Inves-
tigations
75:05B-012
Nitrites
75:02G-003
75:02K-013
75:03F-061
75:05A-004
75:05A-007
75:05B-012
75:05B-044
75:05B-049
75:050-001
Nitrification
75:020-046
75:020-094
Nitrogen
75
75:
75;
75
75:
75
75
75
75
75:
75:
75:
75:
75;
75:
75:
75:
75:
75;
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75;
75:
75:
75:
75:
75:
75:
75;
75;
75:
75:
75;
75:
75:
75;
75:
02A-002
02E-004
02G-034
02G-071
02G-080
02G-082
02G-089
02G-094
02G-095
02G-105
02G-124
02G-126
02J-017
02J-019
02K-002
02K-009
02K-010
02K-012
02K-017
02K-018
02K-020
03C-008
03F-007
03F-018
03F-027
03F-034
03F-043
03F-046
03F-050
03F-053
03F-055
03F-058
03F-061
03F-065
05B-006
05B-017
05B-028
05B-023
05B-030
05B-039
05B-041
05B-044
05B-049
05B-050
05B-060
05C-002
05D-001
05G-013
Nitrogen Compounds
75:02K-002
75:05A-004
75:05B-049
Nitrogen Cycle
75.-02G-126
75:05B-049
Nitrogen Fixation
75:02K-012
75:02K-020
Non-Uniform Flow
75:02F-016
North America
75:02F-023
75:02K-003
North Carolina
75:026-126
75:05A-011
75:058-044
75:05B-060
North Dakota
75:02G-052
75:030-007
75:03F-067
Nuclear Explosions
75:058-035
Nuclear Meters
75:026-074
Nuclear Moisture
Meters
75:020-057
Nuclear Powerplants
75:058-045
Numerical Analysis
75:02F-014
75:02F-017
75:02F-018
75:02F-019
75:02F-021
75:02F-024
75:026-016
75:026-022
75:020-023
75:020-031
75:026-045
75:026-046
75:020-055
75:02G-060
75:02G-073
75:048-004
75:048-009
75:048-011
75:05B-043
75:088-004
Nutrient Removal
75:021-009
75:02J-017
75:058-004
75:058-041
75:05B-042
233
-------
Nutrients
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
02A-
02G-
026-
026-
021-
02J-
02J-
02K-
02K-
02K-
02K-
02K-
03F-
03F-
03F-
03F-
03F-
03F-
03F-
03F-
03F-
03F-
03F-
03F-
05A-
05A-
058-
058-
058-
05B-
05B-
05B-
05B-
05C-
05C-
05G-
05G-
05G-
08D-
002
075
115
023
009
017
019
Oil
012
017
018
020
027
028
035
051
056
058
060
061
062
063
064
065
006
007
003
019
022
•023
•039
•050
•060
•002
•004
013
016
019
001
Oak Trees
75:020-011
Observation Wells
75:02F-003
75:02F-020
75:046-013
75:05A-011
Ohio
75:02G-123
75:02J-001
75:05B-047
75:08A-001
Oil Fields
75:05B-047
Oil Wells
75-.05B-047
Oklahoma
75:02A-002
75:03B-003
75:03F-032
75:040-001
On-site Investigations
75:020-006
75-.02F-006
75:02G-021
75:02G-025
On-Site Investiga-
tions
75:026-052
75-.02G-059
75-.02G-074
75:04B-008
75:05A-007
75:05A-011
75:05B-023
75:05B-034
On-Site Tests
75:020-023
75-.02G-029
75:03C-005
Open Channel Flow
75:03B-004
75:08B-004
75:088-006
Open Channels
75:03B-001
75:03B-004
Operating Costs
75:04A-005
Operations
75:03F-020
Optimization
75:02E-001
75:02E-003
75:02F-001
75:02F-014
75:02F-022
75:02G-030
75:04B-011
75:04B-015
75:058-002
75:05G-007
75:050-008
75:056-024
75:06A-001
75:06C-001
75:088-005
Optimum Development
Plans
75:058-001
Oregon
75:05A-008
75:05A-016
Organic Compounds
75:02G-081
75:026-099
75:05A-006
75:05B-042
Organic Matter
75:026-083
75:026-089
75:026-090
75:026-095
75:026-096
75:026-117
75:02J-019
75:02K-018
75:03F-046
75:05C-003
Organic Wastes
75:05A-006
75:058-048
Orifice Flow
75:026-064
75:03F-057
Orifices
75:02G-064
75:03F-057
Osmotic Pressure
75:03C-005
Overburden
75:026-101
Overland Flow
75:02J-002
75:02J-003
Oxidation-Reduction
Potential
75:02G-069
75:02K-004
Oxides
75:02K-004
Oxygen
75:03F-030
75:05C-008
Oxygen Requirements
75:03C-004
75:05C-008
Oxygenation
75:03C-004
Ozone
75:02F-027
75:03C-003
Parametric Hydro-
logy
75:02E-001
75:02F-001
75:02F-016
75:02F-022
Particle Size
75:02J-013
Pasture Management
75:03F-048
Pastures
75:020-012
75:026-117 .
75:03F-048
Path of Pollutants
75:026-015
75:02J-012
75:05B-003
75:05B-018
75:05B-022
75:056-034
75:056-035
75:058-036
75:058-037
234
-------
Path of Pollutants
(cont.)
75:058-038
75:058-041
75:058-043
75:058-044
75:058-045
75:058-047
75:058-049
Pathology
75:058-061
Peak
75:056-013
Peanuts
75:03F-045
Penetration
75:048-011
75:058-042
75:05G-023
Pennsylvania
75:050-002
75:050-004
75:050-005
Perched Water
75:020-075
Percolating Water
75:03F-025
75:048-010
Percolation
75:020-001
75:020-015
75:020-026
75:020-027
75:020-068
75:020-073
75:020-104
75:03F-025
75:048-010
75:058-041
75:050-023
Permafrost
75:020001
75:020-019
75:02K-001
Permeability
75:02F-019
75:02F-026
75:020-032
75:020-053
75:020-103
75:020-104
75:048-002
75:048-011
Permeameters
75:020-047
75:020-119
75:04A-001
Persistence
75:020-003
Pesticides
75:020-084
75:02J-007
75:058-003
75:050-016
Phase Diagrams
75:02K-004
Phenols
75:020-003
Phosphates
75:02F-027
75:020-099
75:02K-006
75:02K-008
75:02K-011
75:05A-002
75:05A-003
75:05A-012
75:058-010
75:058-039
75:058-042
75:05F-001
Phosphorus
75:02A-002
75:02E-004
75:020-005
75:020-006
75:020-105
75:020-110
75:020-124
75:02H-002
75:02J-017
75:03F-027
75:03F-052
75:03F-062
75:03F-064
75:05A-007
75:05A-012
75:058-013
75:058-019
75:058-023
75:058-024
75:058-031
75:058-039
75:058-040
75:058-042
75:050-002
75:050-013
75:050-025
Phosphorus Compounds
75:05A-003
75:05A-012
75:058-042
Photosynthesis
75:021-002
75:021-013
Phreatophytes
75:038-001
Phreatophytic Control
75:038-001
Physical Properties
75:020-019
75:02K-004
75:050-023
Physicochemical
Properties
75:020-101
Piezometers
75:020-074
75:04A-001
75:048-013
Pine Trees
75:020-011
Pipes
75:020-061
75:04A-005
75:088-001
75:088-005
Planning
75:020-002
75:03F-011
75:04A-004
75:048-005
75:05A-008
75:050-001
75:050-027
75:06A-001
Plant Growth
75:020-001
75:020-009
75:020-041
75:020-054
75:021-012
75:03C-002
75:03C-003
75:03C-004
Plant Morphology
75:020-049
Plant Physiology
75:020-009
75:020-012
75:020-067
75:021-004
75:03C-002
75:03C-004
Plant Tissues
75:020-067
75:021-004
75:021-012
Planting Manage-
ment
75:020-009
Plastic Deformation
75:020-061
Plastic Pipes
75:020-061
75:080-002
75:080-003
Plastics
75:020-061
75:080-002
75:080-003
Pollutants
75:020-011
235
-------
Pollutants
(cont.)
75:05A-006
75:05A-007
75:05A-011
75:05B-022
75:058-032
75:058-036
75:058-037
75:058-047
75:05G-009
Pollution
75:02F-029
75:020-115
75:03F-040
75:048-014
75:05A-013
75:05A-015
75-.05A-016
75:058-051
75:058-059
75:058-061
75:050007
75:05G-016
75:050-018
75:050-019
Pollution Abatement
75:050-009
75:050-014
Pollution Identifi-
cation
75:05A-003
75:05A-007
75:058-043
Pollution Taxes (Charges)
75:050-014
75:050-026
Porous Media
(cont.)
75:02F-018
75:02F-019
75:02F-037
75:020-001
75:020-013
75:020-014
75:020-022
75:020-056
75:020-086
75:04A-001
75:048-014
75:058-044
Portability
75:04A-006
Ports
75:058-020
Ponding
Ponds
75:020-068
75:02F-012
75:02H-002
Pondweeds
75:02H-002
Pore Pressure
75:020-026
75:020-053
75:020-057
Pore Water
75:020-058
Pores
75:020-048
75:020-053
75:020-059
Porosity
75:02F-016
75:048-001
Porous Media
75:02F-004
75:02F-005
75:02F-016
Potable Water
75:05A-013
Potassium
75:020-113
75:020-123
75:02K-014
75:02K-016
75:02K-019
75:03F-056
75:03F-060
75:03F-064
75:05A-014
75:058-010
75:058-023
Potential Flow
75:02F-018
75:020-032
75:048-003
Potentiometric Level
75:02F-012
75:02F-025
75:020-075
75:02L-001
Power Plants
75:058-020
Precipitation (Atmos-
pheric)
75:02A-002
75:021-007
75:058-023
Precipitation Inten-
sity
75:020-012
75:02J-002
75:02J-003
Preservation
75:05A-005
Pressure
75:020-056
Pressure Head
75:020-006
75:020-050
75:020-056
Pressure Head
(cont.)
75:020-057
75:048-011
Pricing
75:050-026
Prior Appropria-
tion
75:03F-069
Probability
75:02F-004
75:058-001
75:058-002
Profiles
75:020-013
75:020-058
75:020-101
Project Planning
75:048-015
Public Health
75:050-001
Pump Testing
75:02F-003
Pumping
75:02A-003
75:02F-025
75:02L-001
75:03F-020
75:048-002
75:048-011
75:048-015
Radiation
75:03F-066
Radioactive Dating
75:02F-008
Radioactivity
75:058-053
75:050-009
Radioactivity
Effects
75:058-035
75:058-053
Radioactivity
Techniques
75:050-009
Radiochemical
Analysis
75:050-009
Radioisotopes
75:02F-006
Raindrops
75:02J-002
Rainfall
75:02A-001
75:02J-006
75:038-002
236
-------
Rainfall
(cont.)
75:03B-005
75:03F-035
75:04A-003
75:088-003
Rainfall Disposition
75:020-103
75:04A-003
Rainfall Intensity
75:02A-001
75:020-012
75:020-060
75:02J-006
75:03B-002
75:04A-002
Rainfall-Runoff Rela-
tionships
75:02A-001
75:02A-002
75:02E-003
75:020-012
75:04A-002
75:04A-003
75:05B-022
75:05B-040
Range Management
75:02A-002
75:050-023
Ranges
75:02A-002
Rates of Application
75:03B-003
Recession Curves
75:02F-006
Recharge
75:02F-021
75:020-045
75:048-010
75:050-011
Recharge Ponds
75:048-008
75:048-010
Reclamation
75:03F-011
75:050-009
75:050-023
Recreation
75:06A-001
Reflectance
75:020-024
Refrigeration
75:05A-003
Regional Analysis
75:058-002
Regional Development
75:03F-011
75:06A-001
Regolith
75:02K-001
Regression Analysis
75:020-001
75:020-034
75:048-012
75:058-048
Regulation
75:048-001
Reliability
75:058-002
Remote Sensing
75:048-013
75:05B-045
Research and Develop-
ment
75:038-003
Research Priorities
75:020-004
75:06E-001
Reservoir Design
75:02J-011
Reservoir Operation
75:02J-011
Reservoir Releases
75:02J-011
Reservoir Silting
75:02J-011
Reservoir Storage
75:06A-001
Reservoirs
75:02J-011
Resource Allocation
75:05G-014
Retardants
75:038-003
Retention
75:020-017
75:020-027
75:020-051
75:020-104
Return Flow
75:02A-003
75:020-071
75:020-080
75:020-092
75:020-102
75:020-106
75:02J-010
75:02J-014
75:02J-017
75:03F-026
75:03F-027
75:03F-028
75:03F-036
75:03F-047
75:03F-067
Return Flow
(cont.)
75:03F-072
75:04A-007
75:04A-010
75:05A-016
75:058-002
75:058-005
75:058-011
75:058-015
75:058-027
75:058-057
75:05B-059
75:058-060
75:058-061
75:05E-003
75:050-012
75:050-016
75:050-019
Revegetation
75:050-023
Reynolds Number
75:04A-001
Rice
75:020-122
75:021-011
75:030009
75:03F-043
75:050-013
Rill Erosion
75:02J-001
75:02J-002
75:02J-007
75:02J-010
75:05A-009
River Basins
75:05A-008
75:058-002
75:050-003
75:050-007
River Forecasting
75:04A-010
River Systems
75:04A-010
Rivers
75:04A-010
Rock Fill
75:04A-001
Rock Properties
75:020-112
Rocks
75:020-112
Root Development
75:020-040
75:020-066
75:020-109
75:021-003
75:021-009
75:030004
237
-------
Root Distribution
75:02G-040
75:02G-066
75:021-003
75:030005
Root Systems
75:020-001
75:020-002
75:02G-022
75:02G-023
75:02G-040
75:02G-041
75:02G-042
75:02G-066
75:021-003
75:021-007
75:021-009
Root Zone
75:020-002
75:020-006
75:02G-040
75:02G-041
75:02G-042
75:02G-055
75-.02G-075
75:02G-106
75:02G-110
75:021-005
75:03F-032
75:058-041
Rotation
75:020-059
Roughness (Hydraulic)
75:08B-006
Roughness Coefficient
75:086-006
Routing
75:06G-002
Runoff
75:02A-001
75:02A-002
75:02E-001
75:02E-004
75:02P-006
75:02G-012
75:02G-059
75:02G-060
75:02J-001
75:02J-002
75:02J-010
75:02J-011
75:02J-013
75:036-002
75:03F-001
75:03F-069
75:04A-003
75:04A-010
75:05A-010
75:058-023
75:05B-048
75:05B-059
75:08E-001
Runoff Forecasting
75:02A-001
75:04A-003
Safe Yield
75:04B-003
Saline Lakes
75:02H-001
Saline Soils
75:021-001
75:030-005
75:03C-007
75:05C-005
Saline Water
75:02F-031
75:021-005
75:02L-001
75:03C-001
75:030-002
75:030-003
75:03F-047
75:04B-011
75:05A-011
75:058-015
75:056-052
75:050-010
Saline Water-Fresh-
Water Interfaces
75:02F-031
75:02F-038
75:02L-001
75:048-011
75:05B-005
Saline Water Intrusion
75:02F-031
75:02L-001
75:05B-005
75:056-018
75:05B-052
Saline Water Systems
75:02F-031
Salt Ceder
75:038-001
Salt Tolerance
75:021-001
75:021-010
75:030-002
75:030-008
75:030-009
75:030-047
Salts
75:
75:
75:
75:
75:
75:
75:
Sampling
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
Sands
02G-015
02G-075
021-005
02R-017
030-002
05G-010
078-002
02E-004
02G-020
02G-027
02G-051
05A-005
05A-006
05A-007
05A-010
05A-011
058-035
058-047
058-048
05G-007
05G-012
078-001
076-002
Salinity
75;
75;
75;
75;
75;
75;
75;
75;
75;
75:
75:
75:
75:
75;
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
02F-005
02G-055
02H-001
021-005
021-010
02K-017
030-001
030-003
030-004
030-007
030-008
030-009
03F-036
03F-047
04A-013
058-005
058-015
05B-027
050-005
05G-003
05B-038
050-008
05G-010
05G-018
"Salt Balance
75:021-005
75:030-005
75:058-005
75:02G-028
75:02G-029
75:02G-055
75:02G-057
75:02G-083
Sandstones
75:02E-002
75:048-002
Saturated Flow
75:02F-004
75:02F-012
75:02F-016
75:02G-001
75:02G-014
75:02G-032
75:02G-047
75:02G-073
Saturated Soils
75:020-004
75:02G-001
75:02G-014
75:02G-032
75:02G-053
75:02G-074
75:020-093
75:02G-122
Saturation
75:020-053
75:020-056
75:02K-003
75:02K-004
238
-------
Scheduling
75:02G-067
75:021-004
75:03F-022
75:03P-036
75:03F-074
75:03F-080
75:03F-081
75:03F-085
Scour
75:02J-003
75:02J-008
75:02J-009
Seasonal
75:020-006
75:020-011
75:02G-103
75:02K-003
75:05B-023
Sedimentation
75:02J-004
75:02J-011
75:02J-018
75:05A-007
Sediment Control
75:02J-014
75:02J-016
75:05A-001
75:086-007
Sediment Discharge
75:02J-012
75:03F-021
75:Q5B-046
Sediment Distribution
75:02J-012
Sediment Load
75:02J-007
75:02J-012
75:03F-021
75:05B-046
75:050-012
75:07B-001
Sediment Transport
75:02E-002
75:02J-001
75:02J-002
75:02J-004
75:02J-012
75:03F-021
75:05B-003
75:07B-001
75:088-001
Sediment Yield
75:02A-002
75:02G-049
75:02J-001
75:03F-021
75:05A-009
75:058-046
75:05G-012
75:07B-001
Sediments
75:02F-032
Sediments
(cont.)
75:02J-007
75:02J-012
75:02J-014
75:02J-016
75:02J-017
75:02J-018
75:02J-019
75:05A-001
75:05A-015
75:058-023
75:058-025
75:05B-055
75:058-060
75:05G-016
75:05G-019
75:050-025
75:086-001
75:088-007
Seed Treatment
75:03F-012
Seeds
75:03F-037
75:05C-008
Seepage
75:020-004
75:02F-012
75:02F-013
75:02F-015
75:02G-012
75:02G-022
75:026-032
75:02G-047
75:02G-068
75:02G-110
75:038-001
75:04A-001
75:048-009
75:048-010
75:05B-047
Seismic Properties
75:048-008
Seismic Studies
75:048-008
Seismic Waves
75:048-008
Seismology
75:04B-008
Semiarid Climates
75:026-049
75:04A-003
Settling Velocity
75:05A-009
Sewage
75:02G-043
75:048-014
75:05E-003
Sewage Disposal
75:02G-043
75:058-016
75:05C-001
Sewage Effluents
75:05C-001
75:05E-003
Sewage Treatment
75:05C-001
75.-05E-003
75:05G-017
Shales
75:08E-001
Shear
75:020-010
Shear Stress
75:020-010
Sheet Erosion
75:02A-001
75:021-001
75:02J-002
75:02J-003
75:05A-009
Sierozems
75:02G-069
Silicates
75:05A-012
Silts
75:02G-029
75:026-049
Silver Iodide
75:05C-003
Simulated Rainfall
75:026-012
75:026-049
75:026-059
75:03B-002
75:05B-022
Simulation Analysis
75:02A-003
75:020-001
75:020-002
75:020-008
75:020-011
75:02E-001
75:02E-002
75:02F-009
75:02F-024
75:026-001
75:026-008
75:026-023
75:026-065
75:02J-002
75:02J-003
75:03F-015
75:04A-004
75:048-005
75:048-012
75:05A-008
75:058-001
75:058-002
75:058-008
75:058-015
75:058-018
75:058-024
75:05B-028
239
-------
Simulation Analysis
(cont.)
75:05G-003
75:06A-001
75:08B-005
Sinks
Sites
Size
Slopes
75:02F-025
75:04B-008
75:056-020
75:08B-005
75:02F-012
75:02F-013
75:02F-015
75:02G-032
75:020-052
75:02J-001
Sludge Disposal
75:05E-002
Slurries
Snow
75:03B-003
75:02C-002
75:02F-006
Snowmelt
75:020-002
75:02J-003
75:05B-023
75:05B-040
Social Aspects
75:05G-026
Social Values
75:05G-026
Sodium
75:02G-035
75:02K-016
75:03F-017
75:05A-014
Sodium Chloride
75:030002
Soil
75:02G-025
Soil Aggregates
75:02G-053
75.-02G-059
75:02G-060
Soil Amendments
75:03F-037
75:05G-023
Soil Analysis
75:02G-102
75:058-041
75:05B-042
Soil Bacteria
75:02G-003
75:02G-037
75.-05B-042
Soil Chemical Proper-
ties
75:02G-035
75:02G-038
75:02G-039
75:02G-102
75-.02G-120
75:02K-013
75:058-013
75:05B-032
75:058-033
Soil Chemistry
75:02F-023
75:02G-034
75:02G-035
75:02G-037
75:02G-038
75:02G-083
75:02G-083
75:026-089
75:026-091
75:02G-102
75:02G-111
75:026-120
75:026-123
75:02K-006
75:02K-007
75:02K-008
75:02K-013
75:02K-016
75:02K-018
75:02K-019
75:03C-004
75:03F-046
75:03F-059
75:05A-015
75:058-013
75:05B-014
75:05B-024
75:05B-031
75:058-032
75:058-033
75:058-042
75:05B-050
75:050-003
Soil Compaction
75:03F-049
75:080-001
Soil Conservation
75:02J-004
75:02J-015
75:02J-018
75:04A-003
Soil Contamination
75:05A-007
75.-05B-047
75:05G-009
Soil Density
75:02G-021
75:02G-025
75:02G-057
75:08D-001
Soil Disposal
Fields
75:058-016
75:05C-001
75:05E-002
Soil Engineering
75:02G-108
Soil Environment
75:02G-037
75:02G-116
75:03C-004
75:03F-008
75:03F-030
75:058-012
75:05C-003
Soil Erosion
75:Q2A-
75:026-
75:026-
75:02J-
75:02J-
75:02J-
75:02J-
75:02J-
75:02J-
75:04A-
75:05A-
75:058-
75-.05B-
•002
•024
•059
•001
002
•003
•013
016
018
003
004
003
040
Soil Filters
75:05A-007
Soil Formation
75:02G-019
Soil Gases
75:026-053
75:03C-004
Soil Horizons
75:026-116
75:02G-122
75:02K-001
75:03F-030
Soil Investigations
75:026-003
75:026-005
75:026-006 -
75:026-008
75:026-010
75:026-021
75:026-025
75:026-034
75:026-035
75:026-036
75:026-037
75:026-038
75:02G-039
75:026-044
75:026-062
75:026-076
75:026-079
75:026-081
75:026-084
75:026-089
75:02G-090
75:026-091
75:026-092
240
-------
Soil Investigations
(cont.)
75:02G-093
75:020-094
75:02G-096
75:02G-097
75:020-098
75:020-099
75:020-107
75:020-108
75:020-109
75:020-111
75:020-112
75:020-113
75:020-114
75:020-115
75:020-116
75:020-117
75:020-118
75:020-120
75:020-121
75:020-122
75:020-123
75:020-124
75:020-125
75:020-126
75:02J-013
75:02K-006
75:02K-007
75:02K-008
75:02K-011
75:02K-015
75:02K-016
75:02K-018
75:02K-019
75:03F-008
75:03F-030
75:03F-059
75:058-010
75:05B-012
75:058-014
75:058-024
75:058-031
75:058-033
75:058-058
75:058-060
75:050004
75:080-001
Soil Management
75:020-035
75:020-051
75:020-056
75:020-059
75:020-060
75:03F-008
75:058-012
75:050-009
Soil Mechanics
75:020-030
75:020-031
75:020-107
75:02J-004
Soil Microorganisms
75:020-069
75:050003
Soil Moisture
75:020-001
75:020-004
75:020-006
Soil Moisture
(cont.)
75:020-009
75:020-011
75:020-012
75:02F-025
75:020-015
75:020-016
75:020-021
75:020-022
75:020-023
75:020-024
75:020-025
75:020-026
75:020-029
75:020-030
75:020-031
75:020-045
75:020-048
75:020-051
75:020-054
75:020-055
75:020-058
75:020-060
75:020-065
75:020-066
75:020-067
75:020-068
75:020-069
75:020-072
75:020-074
75:020-076
75:020-079
75:020-101
75:020-103
75:020-104
75:021-003
75:021-004
75:030-005
75:03F-010
75:03F-015
75:03F-022
75:03F-030
75:03F-031
75:03F-052
75:040-001
75:05A-014
75:058-027
75:058-042
75:058-043
75:050-023
Soil Moisture Meters
75:020-021
75:020-024
75:020-025
75:020-029
75:020-103
Soil Moisture Movement
75:03F-031
Soil Physical Proper-
ties
75:020-012
75:020-016
75:020-017
75:020-021
75:020-025
75:020-031
75:020-042
75:020-052
75:020-053
Soil Physical
Properties
75:020-054
75:020-102
75:030004
75:030005
75:03F-019
Soil Physics
75:020-030
75:020-031
75:030004
Soil Pressure
75:020-027
75:020-036
75:020-045
Soil Profiles
75:020-001
75:020-002
75:020-054
75:020-074
75:020-075
75:020-102
75:020-116
75:020-124
75:021-005
75:058-041
75:078-002
Soil Properties
75:020-005
75:020-023
75:020-024
75:020-027
75:020-029
75:020-031
75:020-036
75:020-039
75:020-040
75:020-041
75:020-042
75:020-044
75:020-051
75:020-053
75:020-054
75:020-059
75:020-060
75:020-076
75:020-101
75:020-105
75:020-108
75:020-117
75:020-119
75:020-120
75:02K-013
75:030004
75:03F-008
75:03F-046
75:058-021
75:058-031
75:058-033
75:058-034
75:058-042
75:080-001
Soil Salinity
75:030-008
75:04A-013
75:050-008
241
-------
Soil Structure
75:02G-017
75:02G-049
75:02G-053
75:020-117
75:05G-023
Soil Surfaces
75:020-002
75:02G-024
75:02G-052
75:02G-056
75:03B-003
Soil Temperature
75:02G-069
Soil Tests
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
02G-021
02G-025
02G-034
02G-037
02G-043
02G-044
02G-062
02G-069
02G-076
02G-092
02G-105
02G-107
02G-108
02G-109
02G-114
02G-115
02G-121
02G-125
02J-013
03F-030
05A-015
05B-041
Soil Texture
75:02G-017
75:02G-036
75:02G-051
75:02G-054
75:02G-083
75:026-084
75:02G-091
75:03F-008
Soil Treatment
75:05E-002
75:05G-009
75:05G-023
Soil Types
75:02G-053
75:020-054
75:02K-001
75:05B-042
Soil Water
75:020-002
75:020-004
75:020-006
75:02P-023
75:02G-012
75:026-016
75:02G-017
75:02G-018
75:026-020
75:02G-021
Soil Water
(cont.)
75:02G-021
75:02G-024
75:026-025
75:020-028
75:02G-029
75:026-030
75:026-031
75:020-032
75:026-036
75:026-040
75:026-041
75:026-042
75:026-045
75:02G-046
75:026-048
75:026-051
75:026-052
75:026-062
75:020-063
75:020-066
75:026-067
75:026-070
75:026-073
75:026-076
75:026-078
75:026-085
75:026-087
75:020-101
75:026-110
75:020-116
75:020-119
75:021-003
75:021-004
75:021-005
75:021-013
75:030-007
75:03F-010
75:03F-019
75:03F-025
75:03F-058
75:03F-070
75:05A-007
75:05B-013
75:05B-042
Soil Water
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
Movement
020-006
02F-011
02G-008
02G-010
020-012
026-033
026-015
026-016
026-018
026-021
026-023
020-026
02G-030
020-031
020-032
02G-04Q
02G-041
020-042
026-045
02G-050
026-052
026-054
026-055
020-057
02G-058
Soil Water Move-
ment (cont.)
75:026-062
75:026-063
75:026-067
75:020-068
75:020-072
75:020-073
75:026-075
75:026-079
75:026-085
75:026-086
75:026-087
75:020-102
75:020-104
75:020-110
75:020-119
75:03C-005
75:03F-019
75:03F-025
75:03F-033
75:03F-038
75:03F-057
75:04B-004
75:04B-009
75:05B-004
75:05B-041
75:05B-053
Soil-Water-Plant
Relationships
75:020-009
75:020-019
75:020-022
75:02G-023
75:026-040
75:026-041
75:026-042
75:026-054
75:026-065
75:026-066
75:02G-067
75:026-069
75:020-090
75:020-103
75:021-003
75:021-004
75:021-011
75:02K-001
75:030003
75:030-004
75:05E-002
Soils
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
75
:02C-002
: 020-011
: 020-001
:02G-003
:02G-005
:026-006
:026-010
:020-018
:02G-021
:02G-024
:026-030
:02G-031
:02G-032
:026-046
:026-055
:02G-056
:020-068
:026-078
: 020-081
242
-------
Soils
(cont.)
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75
75
75
75
75
75
02G-082
02G-083
:02G-084
:02G-088
:02G-089
:02G-090
:02G-092
:02G-093
:02G-094
:02G-097
:02G-098
:02G-099
:02G-105
:02G-107
:02G-111
:02G-113
:02G-118
:023-120
:02G-122
:02G-123
:02K-018
:02K-019
:03F-043
:03F-059
:04A-013
:05A-015
:05B-012
:05B-022
:05B-031
:05B-058
:05B-060
:05G-004
:05G-023
:07B-002
:08B-001
:08D-001
Solar Radiation
75:02A-001
Solubility
75:02K-004
Solutes
75:02F-005
75:02G-001
75:020-008
75:02G-013
75:02G-055
75:02G-058
75:02G-075
75:03F-033
75:056-037
75:05G-036
Sorghum
75:03C-001
75:03F-003
75:03F-004
75:03F-012
75:03F-023
Sorption
75:02G-016
75:05B-024
75:058-031
75:058-032
Southwest U.S.
75:05G-003
75:05G-023
Soybeans
75:02G-040
75:02G-041
75:026-042
75:02K-020
75:03F-041
75:03F-049
75:03F-052
75:03F-063
75:03F-064
75:03F-067
75:058-030
Spatial Distribution
75:02F-016
75:02G-036
Specific Conductivity
75:05A-014
Specific Weight
75:02L-001
Specific Yield
75:02F-003
75:02F-017
Spectrophotometry
75:02G-029
Spring Waters
75:02K-003
Sprinkler
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
75:
Irrigation
02G-009
02G-069
03C-002
03F-023
03F-024
03F-025
03F-032
03F-044
03F-079
03F-080
03F-081
03F-082
03F-085
04A-011
04A-012
04A-013
05C-005
08B-002
Sprinkling
75:030002
Stable Isotopes
75:02F-008
Stability
75:026-027
75:026-068
Standards
75:058-002
75:058-020
75:056-003
State Jurisdiction
75:056-002
Statistical Models
75:02F-016
Statistical Models
(cont.)
75.-02J-012
Statistical Methods
75:02F-004
Statistics
75:048-010
Steady Flow
75:02F-013
75:02F-016
75:026-001
75:026-057
75:026-059
75:026-073
Step Functions
75:038-001
Stochastic Pro-:
cesses
75:02F-004
75:02F-016
75:02J-012
75:058-001
75:058-002
Storage
75:026-059
75:026-060
75:05A-003
Storage Capacity
75:026-051
Storage Coefficient
75:02F-019
75:02L-001
75:048-002
Storm Drains
75:088-001
Storm Runoff
75-.02J-001
75:02J-004
75:05A-014
75:058-022
Storms
75:026-012
Stratification
75:02F-005
75:02F-012
Stream Erosion
75:02J-002
75:02J-003
Streamflow
75:02A-003
75:02J-003
75:03F-069
75:05A-014
75-.05B-048
75:06A-001
Streams
75:02C-001
75:026-019
243
-------
Streams
(cont.)
75
75
75
Stress
75
75
Stress Analysis
75
75
Strontium
75
03B-001
05B-001
05B-002
02G-067
021-004
02G-067
021-004
021-007
Strontium Radioiso-
topes
75:05G-009
Subarctic
75:02C-001
Subsoil
75:02G-114
75:020-126
75:02K-012
Subsurface Drainage
75:02G-073
75:04B-009
75:05B-039
Subsurface Drains
75:04B-009
75:088-001
Subsurface Flow
75:020-006
75:02F-037
Subsurface Investi-
gations
75.-05B-051
Subsurface Irrigation
75:020-065
75:03F-019
75:03F-057
Subsurface Runoff
75:02F-006
75:02F-012
Subsurface Waters
75:02F-014
75:02F-020
75:02F-023
75:02G-011
75:02G-030
75:02G-045
75:02G-056
75:058-004
Subtropic
75:04A-003
Suburban Areas
75:04A-002
Sugar Beets
75:021-012
Sugar Beets
(cont.)
75:03F-022
75:03F-037
Sulfates
75:021-007
75:05B-039
Sulfur
75:02G-090
75:02G-105
75:02K-013
75:058-032
Sulfur Bacteria
75:05A-011
Sulfur Compounds
75:058-032
7,5:05G-023
Surface-Groundwater
Relationships
75:02A-003
75:02F-017
75:048-001
75:048-012
75:058-005
75:050-004
Surface Irrigation
75:02G-106
75:03C-001
75:03F-003
75:03F-008
75:03F-027
75:03F-028
75:03F-029
75:03F-068
75:03F-072
75:03F-075
75:03F-076
75:03F-077
75:03F-081
75:04A-005
75:058-046
75:058-061
Surface Runoff
75:02A-001
75:02A-002
75:02E-003
75:02J-001
75:05A-006
75:058-011
75:058-023
75:058-040
75:058-049
Surface Tension
75:020-010
Surface Waters
75:04A-004
75:04B-005
75:05A-011
75:058-019
75:058-022
75:05B-047
75:05G-002
75:05G-013
75:050-023
75:06A-001
Surveys
75:05G-026
Suspended Load
75:02A-001
75:02J-003
75:02J-012
75:058-046
75:050-012
Suspended Solids
75:02J-002
75:02J-012
75:058-046
75:05G-012
Systems Analysis
75:02E-003
75:02F-022
75:048-015
75:05A-008
75:058-001
75:058-002
75:058-020
75:050-003
75:050-007
75:050-008
75:06A-001
75:088-005
Tailwater
75:04A-007
Taste
75:058-047
Taxes
75:050-018
75:070001
Tax Rates
75:05G-018
Technology
75:05G-008
75:05G-015
Temperature
75:020-002
75:020-005
75:02F-008
75:02F-005
75:02F-023
75:02F-037
75:02G-013
75:020-017
75:02G-094
75:02K-003
75:02K-018
75:048-010
75:058-020
75:058-025
75:058-045
Tensiometers
75:020-006
75:02G-018
75:020-025
75:020-027
75:020-052
75:020-057
75:020-075
75:021-005
75:03F-045
244
-------
Testing
75:02F-003
Texas
75:02A-001
75:02F-026
75:05A-009
75:05B-002
75:05B-021
75:05B-058
75:05G-011
75:060-002
Theis Equation
75:02P-019
75:02F-024
75:02L-001
75:04B-006
Theoretical Analysis
75:020-010
75:02E-003
75:02F-013
Thermal Capacity
75:05B-020
Thermal Pollution
75:05B-020
75:056-045
Thermal Water
75:02F-037
Thermodynamics
75:02G-012
75:02G-101
Thin Films
75:03B-003
Thunderstorms
75:02J-006
Tides
75:05B-038
Tile Drainage
75:056-039
Tile Drains
75:05B-004
Tiles
Till
Time
75:04B-004
75:05B-036
75:05B-037
75:02G-052
75:03F-012
75:03F-013
75:05A-003
Time Lag
75:05A-014
Tobacco
75:020-003
Topography
75:05G-004
Topsoil
75:02A-002
Trace Elements
75:05A-003
75:05G-021
Tracers
75:02F-006
75:02G-046
75:02G-121
75:058-034
Tracking Techniques
75:05G-009
Tractive Forces
75:02J-004
Trafficability
75:03F-032
Transmissivity
75:02F-010
75:02F-014
75:02F-019
75:02F-020
75:02F-021
75:02F-022
75:04A-001
75:04B-001
75:04B-002
Transpiration
75:020-003
75:020-004
75:020-009
75:02G-066
75:021-003
75:021-005
75:021-010
75:021-013
75:03C-004
Transpiration Con-
trol
75:020-003
Travel Time
75:021-005
75:04B-008
Treatment Facilities
75:05B-002
Turf
Tritium
75
75
75
:02F-006
:02F-025
i05B-035
Tubes
75:026-074
Tundra
75:02C-002
Turbidity
75:
Turbulent
75
75
05B-046
Flow
;020-010
:08B-004
75:021-010
75:03F-050
Turf Grasses
75:021-010
75:03F-050
Uniformity Coef-
ficient
75:03F-025
75:03F-032
United States
75:03F-020
75:05G-008
Unsaturated Flow
75:020-006
75:02F-018
75:02F-037
75:02G-001
75:02G-016
75:02G-022
75:02G-023
75:020-030
75-.02G-031
75:020-045
75:02G-050
75:020-055
75:020-057
75:02G-068
75:02G-072
75:020-075
75:020-104
75:048-004
Unsteady Flow
75:02F-003
75:02F-014
75:02F-016
75:02F-017
75:02F-018
75:02F-024
75:020-001
75:020-055
75:020-057
75:020-104
75:048-004
Urban Hydrology
75:04A-002
Urban Run-off
75:05A-001
75:058-022
Urbanization
75:05A-001
75:06C-001
75:06E-002
Ureas
Utah
75:03F-043
75:03F-050
75:03F-061
75:02F-035
Vapor Compression
Distillation
75:02K-002
245
-------
Vapor Pressure
75:020-005
Variability
75:02G-103
75:02K-003
75:086-004
Vegetation
75:020-006
75:020-011
75:02K-001
75:038-001
75:038-004
Vegetation Effects
75:02A-002
75:038-004
75:04A-003
75:058-022
Vegetation Regrowth
75:05G-023
Velocity
75:02F-006
75:02G-050
75:020-058
75:021-005
75:088-004
Virginia
75:03F-063
Viscosity
75:02F-013
75:02F-015
Void Ratio
75:02G-101
Volumetric Analysis
75:02G-018
Washington
75-.05A-016
Waste Assimilative Ca-
pacity
75:058-020
Waste Disposal
75:02G-005
75:03F-017
75:040-001
75:05A-011
75:058-044
75:05E-001
Waste Disposal Wells
75:05E-001
Waste Storage
75:058-044
Waste Treatment
75:040001
Waste Water
75:02F-027
75:02G-006
75:05A-012
75:05C-002
75:050-001
Waste Water
(cont.)
75:05F-001
75:056-017
75:05G-021
75:05G-022
75:06E-001
75:050-001
Waste Water Disposal
75:058-044
75:050-001
75:06E-001
Waste Water Treatment
75:02F-027
75:02G-080
75:058-013
75:05F-001
75:06E-001
Wastes
75:058-001
75:058-036
75:058-037
75:058-047
75:05E-001
Water
75:02K-004
75:05A-012
75:058-026
Water Allocation
(Policy)
75:05G-008
75:07C-001
Water Analysis
75:02K-002
75:05A-003
75:05A-010
75:05A-012
75:058-004
75:058-047
Water Balance
75:02G-060
75:058-019
Water Chemistry
75:02F-023
75:02F-026
75:02G-019
75:02G-071
75:02H-001
75:02H-002
75:02K-001
75:02K-003
75:02K-004
75:05A-012
75:05A-014
75:058-049
Water Conservation
75:02F-034
75:02G-060
75:03F-024
75:03F-026
75:03F-031
75:03F-037
75:03F-072
75:03F-077
Water Conservation
75:03F-078
75:03F-080
75:03F-081
75:03F-083
75:04A-006
75:04A-007
75:07C-001
Water Consumption
75:020-004
Water Control
75:04A-005
Water Conveyance
75:06G-002
Water Cooling
75:058-045
Water Delivery
75:04A-005
75:06E-002
Water Demand
75:03F-020
75:03F-026
75:06E-002
Water Distribution
(Applied)
75:026-015
75:04A-005
75:06E-002
75:07C-001
Water Hyacinth
75:02H-002
Water Law
75:056-010
75:06E-002
Water Level Fluc-
tuations
75:048-013
Water Level Record-
ers
75:048-013
Water Levels
75:02C-001
75:02F-021
75:02F-022
Water Loss
75:020-002
75:020-003
75:038-001
Water Management
(Applied)
75:02G-060
75:026-070
75:02L-001
75:03C-005
75:048-012
75:058-027
75:056-002
75:056-003
75:056-010
75:07C-001
246
-------
Water Measurement
75:02G-029
75:04A-006
75-.05G-015
Water Policy
75:03P-011
75:056-002
75:05G-010
Water Pollution
75:02F-028
75:02F-029
75:020-015
75:02G-020
75:02G-071
75:02G-080
75:02J-012
75:03F-027
75:03F-028
75:05A-003
75:05A-006
75:05A-007
75:05A-011
75:05A-013
75:05A-016
75:05B-026
75:05B-029
75:058-034
75:058-038
75:056-044
75:056-047
75:056-048
75:05B-049
75:058-051
75:05B-052
75:058-058
75:056-059
75:05C-002
75:050-007
75:05E-003
75:05G-002
75:056-010
75:05G-012
75:05G-021
75:05G-024
Water Pollution Con-
trol
75:05A-010
75:058-026
75:05C-002
Water Pollution
Sources
75:02J-012
75:04B-007
75:05A-003
75:05A-012
75:058-003
75:05B-022
75:056-026
75:056-035
75:058-036
75:058-037
75:058-041
75:058-044
75:058-045
75:058-047
75:058-048
75:058-049
Water Pressure
75:020-021
75:020-025
75-.02G-068
Water Properties
75:02K-004
75:05A-003
75:05A-012
Water Quality
75:02E-002
75:02E-004
75:02F-023
75:02F-028
75:02F-029
75:02F-036
75:02F-038
75:02G-011
75:020-071
75:02H-002
75:02J-007
75:02J-011
75:02J-017
75:02K-003
75:03C-005
75:030006
75:03F-026
75:03F-040
75:03F-042
75:03F-084
75:046-014
75:05A-002
75:05A-004
75:05A-006
75:05A-007
75:05A-008
75-.05A-013
75:05A-016
75:058-005
75:058-006
75:056-007
75:058-008
75:058-021
75:056-026
75:058-028
75:056-029
75:058-036
75:058-037
75:056-038
75:058-047
75:058-049
75:058-051
75:058-052
75:058-057
75:056-058
75:058-059
75:056-061
75:050-004
75:050-007
75:05E-003
75:05F-001
75:050-007
75:050-012
75:050-015
75:050-016
75:050-019
75:050-021
75:050-022
75:050-024
75:050-025
75:050-027
75:060-001
Water Quality
Control
75:02E-004
75:02F-028
75:02F-029
75:048-007
75:05A-002
75:05A-005
75:05A-013
75:05A-016
75:056-001
75:058-002
75:058-007
75:058-020
75:056-027
75:058-057
75:05E-003
75:050-001
75:050-002
75:050-003
75:050-005
75:050-006
75:050-008
75:050-010
75:050-012
75:050-013
75:050-015
75:050-019
75:050-021
75:050-022
75:050-024
75:050-025
75:050-027
Water Quality
Standards
75:050-002
75:050-005
75:060-001
Water Requirements
75:02D-009
Water Resources
75:02F-038
75:03F-011
75:04A-010
75:05A-008
75:050-001
75:050-010
75:050-028
75:06A-001
Water Resources
Development
75:048-012
75:050-005
75:060-002
Water Reuse
75:058-021
75:06E-002
Water Rights
75:048-001
75:046-007
75:05G-006
75:06E-002
75:07C-001
Water Sampling
75:02F-028
75:02F-029
247
-------
Water Sampling
(cont.)
75:02G-020
75:05A-010
75:05G-025
Water Shortage
75:06C-001
Water Spreading
75:048-008
75:058-021
Water Storage
75:020-051
Water Supply
75:02B-001
75:020002
75:03F-011
75:03F-026
75:03F-069
75:048-007
75:048-015
75:05G-008
75:05G-010
75:05G-017
75:06G-002
Water Supply Develop-
ment
75:028-001
Water Table
75:02F-017
75:02F-035
75:02G-013
75:02G-023
75:02G-073
75:026-074
75:02G-088
75:026-110
^5:038-001
75:03F-051
75:048-009
75:048-011
75:058-005
75:088-003
Water Table Aquifers
75:02F-013
75:02F-015
75:048-004
75:058-044
Water Temperature
75:02D-005
75:02K-003
75:048-010
75:058-045
Water Transfer
75:058-005
75:06C-001
75:06E-002
Water Treatment
75:026-080
Water Utilization
75:020-006
75:02D-009
75:03F-009
Water Utilization
(cont.)
75:03F-020
75:03F-026
75:06A-001
Water Vapor
75:02D-003
Water Wells
75-.02F-003
75:02F-018
75:02F-021
75:048-001
75:048-003
75:048-011
75:058-035
Water Yield
75:08E-001
Water Zoning
75:02F-034
Watershed Management
75:02A-002
75:026-056
75:02J-004
75:040-001
75:058-003
75:058-007
Watersheds (Basins)
75:020-011
75:02E-001
75:026-011
75:026-012
75:026-049
75:02J-001
75:02J-002
75-.02J-003
75:02J-004
75:02J-017
75:04A-002
75:040-001
75:058-006
75:058-008
75:058-048
Weather
75:020-005
75:020-007
75:038-005
Weather Modification
75:028-001
75:020-007
75:038-005
Weather Patterns
75:038-005
Wells
75:02L-001
75:04A-001
75:048-004
75:048-015
75:05E-001
West Virginia
75:058-052
Wettability
75:026-053
Wetting
75:020-002
75:026-027
75:026-031
75:026-048
75:026-050
75:026-053
Wheat
75:020-001
75:020-002
75:021-006
75:030-004
75:03F-003
75:03F-012
75:03F-034
75:03F-063
75:050-008
Wind Velocity
75:020-005
75:038-003
75:03F-D24
75:03F-044
Winds
75:038-003
75:03F-032
Wyoming
75:05A-016
Yield Equations
75:021-006
75:03F-010
Zeta Potential
75:026-047
Zinc
75:026-083
75:026-115
75:02K-015
Zone of Aeration
75:030-004
Zone of Saturation
75:026-074
248
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-600/2-77-094
2.
3. RECIPIENT'S ACCESSION>NO.
TITLE AND SUBTITLE
SELECTED IRRIGATION RETURN FLOW QUALITY
ABSTRACTS 1975
5. REPORT DATE
May 1977 (Issuing
6. PERFORMING ORGANIZATION CODE
AUTHOR(S) ~~ ~
G. V. Skogerboe, S. W. Smith, and W. R. Walker
8. PERFORMING ORGANIZATION REPORT NO.
PERFORMING ORGANIZATION NAME AND ADDRESS
Agricultural Engineering Department
Colorado State University
Fort Collins, Colorado 80523
10. PROGRAM ELEMENT NO.
1HB617
11. CONTRACT/GRANT NO.
R-800426
12. SPONSORING AGENCY NAME AND ADDRESS
Robert S. Kerr Environmental Research Lab,
Office of Research and Development
U.S. Environmental Protection Agency
Ada, Oklahoma 74820
- Ada, OK
13. T.y?E Of REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/15
15. SUPPLEMENTARY NOTES
16. 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 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. 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, and the third annual issue covers calendar years 1972 and 1973, and the fourth
annual issue lists abstracts of 1974 publications. This annual issue lists 501
publications printed in 1975. This report was submitted in fulfillment of Grant
Number R-800426 under the sponsorship of the Office of Research and Development,
Environmental Protection Agency.
(Skogerboe-Colorado State)
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COS AT I Field/Group
Fertilizers, Irrigation, Irrigated land,
Salinity, Water pollution
Irrigation systems, Irri-
gation water, Nitrates,
Phosphates, Return flow,
Water pollution effects,
Water pollution sources,
Water quality control
2C
18. DISTRIBUTION STATEMENT
Release Unlimited
19.
Unclassified
257
20. SECURITY CLASS (This page)
22. PRICE
EPA Form 2220-1 (9-73)
249
U.S. GOVERNMENT PRINTING OFFICE: 1977-757-056/6436 Region No. 5-11
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