EPA-R2-72-094
November 1972                Environmental Protection Technology Series
            Selected  Irri^Jion Return  Flow
             Quality Abstracts 1968-1969

                                      Office of  Research and Monitoring

                                      U.S. Environmental Protection Agency

                                      Washington, D.C. 20460

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            RESEARCH REPORTING SERIES
Research reports of the  Office  of  Research  and
Monitoring,  Environmental Protection Agency, have
been grouped into five series.  These  five  broad
categories  were'established to facilitate further
development  and  application   of   environmental
technology.   Elimination  of traditional grouping
was  consciously  planned  to  foster   technology
transfer   and  a  maximum  interface  in  related
fields.  The five series are:

   1*  Environmental Health Effects Research
   2.  Environmental Protection Technology
   3.  Ecological Research
   4.  Environmental Monitoring
   5.  Socioeconomic Environmental Studies

This report has been assigned to the ENVIRONMENTAL
PROTECTION   TECHNOLOGY   series.    This   series
describes   research   performed  to  develop  and
demonstrate   instrumentation,    equipment    and
methodology  to  repair  or  prevent environmental
degradation from point and  non-point  sources  of
pollution.  This work provides the new or improved
technology  required for the control and treatment
of pollution sources to meet environmental quality
standards.

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                                                     EPA-R2-72-094
                                                     October  1972
         SELECTED IRRIGATION RETURN FLOW

           QUALITY ABSTRACTS 1968-1969



                First Annual Issue
                        by
               Gaylord V. Skogerboe
                  Venus T. Sahnl
                  Wynn R. Walker
              Project No. 13030  FVN
     Dr. James P.  Law, Jr., Project Officer
Robert S.  Kerr Environmental Research Laboratory
        Environmental Protection  Agency
               Ada, Oklahoma 74820
                   Prepared for
       OFFICE  OF RESEARCH AND MONITORING
     U. S.  ENVIRONMENTAL PROTECTION AGENCY
             WASHINGTON, D. C. 20460
   For sale by the Superintendent of Documents, U.S. Government Printing Office
               Washington, D.C. 20W2 - Price S2.75

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                    EPA Review Notice
This report has been reviewed by the Environmental Protection
Agency and approved for publication.  Approval does not signify
that the contents necessarily reflect the views and policies
of the Agency nor does mention of trade names or commercial
products constitute endorsement or recommendation for use.

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                          ABSTRACT
Research related to the quality of irrigation return flow
is being conducted at numerous institutions throughout the
western United States.  Related work is also underway at
other institutions in the United States, as well as other
portions of the world.  Approximately 100 sources of
material have been searched for articles pertinent to the
National Irrigation Return Flow Research and Development
Program.  These articles describe water quality problems
resulting from irrigated agriculture, potential technolo-
gical solutions for controlling return flows, recent
research pertinent to return flow investigations, and lit-
erature associated with institutional constraints in irri-
gation return flow quality control.

This first annual issue of SELECTED IRRIGATION RETURN FLOW
QUALITY ABSTRACTS covers publications printed in 1968 and
1969.  This report was submitted in fulfillment of Project
Number 13030FVN, Contract 14-12-01, under the sponsorship
of the Office of Research and Monitoring, Environmental
Protection Agency.
Key Words:  Fertilizers, Irrigated Land, Irrigated Systems,
Irrigation Water, Nitrates, Phosphates, Return Flow, Salin-
ity, Water Pollution Effects, Water Pollution Sources,
Water Quality Control
                             111

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                      FOREWORD
The first annual issue of SELECTED IRRIGATION RETURN QUALITY
ABSTRACTS has been compiled from approximately 100 sources
of material covering calendar years 1968 and 1969.  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 Pollution
Problems of Irrigation Return Flow" prepared by the Utah
State University Foundation (see abstract 68-69:056-028 on
page 129) contains a bibliography of articles pertinent to
Irrigation Return Flow Quality Control.  The references in
this bibliography include articles and reports prior to 1968.

The first annual issue contains more than 400 abstracts of
documents published during calendar years 1968 and 1969.
The abstracts have been placed into sections according to
the category and subgroup classifications used by the Water
Resources Scientific Information Center  (WRSIC) as published
in the report, "Water Resources Thesaurus."  The abstracts
have been forwarded to WRSIC for inclusion in their bi-monthly
publication, "Selected Water Resources Abstracts."
                         v

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                   TABLE  OF  CONTENTS

Section                                                  Page

   I      WATER CYCLE  - GENERAL (Group 02A)                1

   II     WATER CYCLE  - EVAPORATION AND TRANSPIRA-
            TION  (Group 02D)                               3

   III    WATER CYCLE  - STREAMFLOW AND RUNOFF
             (Group 02E)                                   15

   IV     WATER CYCLE  - GROUNDWATER (Group 02F)          19

   V      WATER CYCLE  - WATER IN SOILS (Group 02G)       37

   VI     WATER CYCLE  - WATER IN PLANTS (Group 021)      63

   VII!   WATER CYCLE  - EROSION AND SEDIMENTATION
             (Group 02J)                                   73

   VIII   WATER CYCLE  - CHEMICAL PROCESSES (Group 02K)   81

   IX     WATER SUPPLY AUGMENTATION AND CONSERVATION -
            SALINE WATER  CONVERSION (Group 03A)          89

   X      WATER SUPPLY AUGMENTATION AND CONSERVATION -
            WATER YIELD IMPROVEMENT (Group 03B)          91

   XI     WATER SUPPLY AUGMENTATION AND CONSERVATION -
            USE OF WATER  OF  IMPAIRED QUALITY  (Group 03C) 93

   XII    WATER SUPPLY AUGMENTATION AND CONSERVATION -
            CONSERVATION  IN  DOMESTIC AND MUNICIPAL USE
             (Group 03D)                                   95

   XIII   WATER SUPPLY AUGMENTATION AND CONSERVATION -
            CONSERVATION  IN  AGRICULTURE (Group 03F)      97

   XIV    WATER QUANTITY  MANAGEMENT AND CONTROL -
            CONTROL OF WATER ON THE SURFACE  (Group 04A) 109

   XV     WATER QUANTITY  MANAGEMENT AND CONTROL -
            WATERSHED  PROTECTION (Group 04D)             115

   XVI    WATER QUALITY MANAGEMENT AND PROTECTION -
            IDENTIFICATION OF POLLUTANTS (Group 05A)    117

   XVII   WATER QUALITY MANAGEMENT AND PROTECTION -
            SOURCES OF POLLUTION (Group 05B)             121
                           Vll

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               TABLE OF  CONTENTS (Cont.)
Section                                                  Paqe
   XVIII  WATER QUALITY MANAGEMENT AND PROTECTION -
            EFFECTS OF POLLUTION (Group 05C)            131

   XIX    WATER QUALITY MANAGEMENT AND PROTECTION -
            WASTE TREATMENT  PROCESSES (Group 05D)       135

   XX     WATER QUALITY MANAGEMENT AND PROTECTION -
            ULTIMATE DISPOSAL  OF WASTES (Group 05E)      139

   XXI    WATER QUALITY MANAGEMENT AND PROTECTION -
            WATER TREATMENT  AND  QUALITY ALTERATION
            (Group 05F)                                  141

   XXII   WATER QUALITY MANAGEMENT AND PROTECTION -
            WATER QUALITY  CONTROL (Group 05G)            143

   XXIII  WATER RESOURCES  PLANNING - TECHNIQUES OF
            PLANNING  (Group  06A)                         149

   XXIV   WATER RESOURCES  PLANNING - EVALUATION
            PROCESS  (Group 06B)                          151

   XXV    WATER RESOURCES  PLANNING - COST  ALLOCA-
            TION, COST SHARING,  PRICING/REPAYMENT
            (Group 06C)                                  155

   XXVI   WATER RESOURCES  PLANNING - WATER LAW AND
            INSTITUTIONS  (Group  06E)                     157

   XXVII  RESOUCES DATA -  NETWORK DESIGN (Group OVA)    159

   XXVIII RESOURCES DATA - DATA  ACQUISITION (Group 07B) 161

   XXIX   PESOURCES DATA - EVALUATION,  PROCESSING AND
            PUBLICATION (Group 07C)                      169

   XXX    ENGINEERING WORKS  -  STRUCTURE  (Group 08A)      171

   XXXI   AUTHOR INDEX                                   173

   XXXII  SUBJECT INDEX                                  183

   XXXIII ACKNOWLEDGMENTS                                211
                         Vlll

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                                  SECTION I


                      WATER CYCLE - GENERAL  (Group 02A)


 68-69:02A-001
 DRAINAGE DESIGN THEORY AND PRACTICE,
 Nwa, E. U., and Twocock, J. G.
 Ministry of Agriculture, Fisheries and Food, Cambridge, England.  Field
 Drainage Experiment Unit.
 Journal of Hydrology, Vol. 9, No. 3, p 259-276, November 1969.  10 fig,
 2 tab, 15 ref.

 Descriptors:  *Drainage systems, *Soil water movement, *Groundwater move-
 ment, *Drainage engineering, Water management  (Applied), Drainage prac-
 tices, Evaluation, Design, On-site investigations. Mathematical studies,
 Model studies, Ditches, Drainage programs, Agricultural engineering.
 Identifiers:  Drainage design theory.

 Several drainage equations were chosen to compare them with the performance
 of an existing drainage scheme.  A review of the drainage theories chosen is
 reported.  The auger-hole method was used to determine the average hydraulic
 conductivity used in the calculation, and the variable drainable porosity
 was determined using Taylor's method.  The drain discharge and the shape of
 the water table were determined by means of a flowmeter, and lines of pie-
 zometers, respectively.  Two rainfree periods were selected for the experi-
 ment.  The water table profile tends to indicate an essentially flat water
 surface.  All the equations tested, except Luthin's, gave an average calcul-
 ated spacing which is larger than the actual spacing.  It is- concluded that
 the site could perform as well as it is doing now with a wider spacing.  More
 research is recommended before one or two equations could be chosen to aid
 the design of drainage schemes.


 68-69.-02A-002
 WATER DISTRIBUTION UNDER SPRINKLER IRRIGATION,
 Pair, Claude H.
 Agricultural Research Service, Kimberly, Idaho, Snake River Research Center.
 Transactions of the American Society of Agricultural Engineers, Vol. 11,
 No. 5, p 648-651, September-October, 1968.  7 tab.

 Descriptors:  *Irrigation efficiency, *Irrigation systems, *Water distribu-
 tion  (Applied), *Sprinkler irrigation, Wind velocity, Rates of application,
 *Uniformity coefficient, Laterals, Infiltration, Idaho, Distribution systems.

 Water distribution from a handmove sprinkler system was studied during a
 normal irrigation season in southern Idaho.  Five types of sprinkler systems
 operating individually and three types of systems operating simultaneously
 had uniform sprinkler heads, nozzle sizes, sprinkler spacing on the lateral,
 nozzle pressure and wind conditions.  Water distribution was compiled from
 spray catch cans.  Comparison of water distribution from three types of
 sprinkler systems operating simultaneously showed that the straight-lateral,
 self-propelled sprinkler gave a higher coefficient of uniformity than the
handmove or side move with trailer line systems.  Multiple irrigations by
handmove portable sprinkler laterals gave acceptable seasonal water distri-
bution as measured by the Christiansen coefficient of uniformity, even
 though some individual irrigations yielded poor water distribution.

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                                     SECTION II


               WATER CYCLE - EVAPORATION AND TRANSPIRATION  (Group 02D)


68-69:020-001
POTENTIAL EVAPORATION AS A MANIFESTATION OF REGIONAL EVAPORATION,
Morton, F. I.
Department of Energy, Mines, and Resources, Ottawa, Ontario, Canada, Hydrologic
Sciences Division.
Water Resources Research, Vol. 5, No. 6, p 1244-1255, December 1969.  5 fig, 2 tab,
14 ref.

Descriptors:  *Evaporation, *Mathematical models, Energy budget, Heat balance, Water
balance, Mass transfer, Meteoric water, Meteorology, Microenvironment, Saturation,
Solar radiation, Temperature, Vapor pressure, Water loss, Evaporators, Humidity,
Evapotranspiration.
Identifiers:  Potential evaporation.

The temperature and humidity of the lower atmosphere are treated as causes of evapor-
ation from a small continuously moist area and as effects of evaporation from a large
area with variable moisture supply.  This leads to the formulation of a model in
which the sum of the regional and potential evaporation is equal to the evaporation
equivalent of the absorbed insolation.  Such a formulation permits the regional evap-
oration, a product of climatic, soil moisture, and vegetation processes, to be esti-
mated by its effects on climatologic or evaporimeter observations.  Test data are
derived from class A evaporation pan observations from the near-arid regions of the
southwestern United States, and the near-humid regions of Ireland and from records of
rainfall and runoff for Irish river catchments.  Comparisons .with the model predic-
tions provide good evidence for the validity of the model and interesting insights
into its hydrologic and climatologic implications.
68-69:020-002
AN EMPIRICAL METHOD FOR ESTIMATING MONTHLY POTENTIAL EVAPOTRANSPIRATION IN NEVADA,
Behnke, Jerold J., and Maxey, George B.
Agricultural Research Service, Fresno, California.
Journal of Hydrology, Vol. 8, No. 4, p 418-430, August 1969.  4 fig, 3 tab, 11 ref.

Descriptors:  *Evaporation, *Nevada, Arid lands, Lysimeters, Estimating, Evaporation
pans, Climates, Topography, Weather, Solar radiation, Evapotranspiration.
Identifiers:  Thornthwaite evapotranspiration.

Monthly potential evapotranspiration values were obtained for several stations
throughout the State of Nevada using the Thornthwaite and Olivier equations.  The
Olivier equation correlated well with lysimeter and adjusted pan data as an estimate
of ET.  On an annual basis the Thornthwaite equation was approximately 50% too low.
A technique was developed to estimate wet bulb depression from temperature data.
This made it possible to solve the Olivier equation using only temperature data as
input.  Climatic conditions in Nevada were such that it was possible to apply the dry
adiabatic lapse rate to a centrally located base station to obtain temperature values
for other locations lacking climatic data.  On a monthly basis, this 'modified' Oliv-
ier equation correlated satisfactorily with the original equation for Nevada loca-
tions ranging in elevation from 2171 to 5136ft and in latitude from 36 deg to 41 deg
N.
68-69:020-003
EVAPORATION FROM DRYING SURFACES BY THE COMBINATION METHOD,
Fuchs, M., Tanner, C. B., Thurtell, G. W., and Black, T. A.
Wisconsin University, Madison, Department of Soil and Water Sciences.
Agronomy Journal, Vol. 61, No. 1, p 22-26, January-February, 1969.  3 fig, 1 tab,
22 ref.

Descriptors:  *Evaporation, Soil temperature, Heat flow.
Identifiers:  Combination formula, *Aerodynamic transfer coefficient.

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 The  combination formula which explicitly includes  the  surface  temperature  is used  to
 predict the hourly evaporation from a drying bare  soil.   The formula  is valid  regard-
 less of the water vapor saturation deficit at the  surface,  but the  measurement of  the
 surface temperature limits  its application to surfaces having  a well-defined boundary
 with the atmosphere.   Agreement with hourly evaporation  measured  by lysimetry  at the
 same site was  only fair because of a thermal lag in  the  energy balance of  the  lysim-
 eter,  but very good (within 1%)  for the  average daily  values where  the effect  of
 thermal lag is negligible.   All combination formulas use an aerodynamic transfer co-
 efficient,  which must  includeadiabatic profile corrections  unless sensible heat flux
 density is  small relative to evaporation.   Eddy correlation measurements of the sens-
 ible heat flux density into the air confirmed the  transfer  coefficient used.   It is
 finally shown  that the additional  measurement of the water  vapor  pressure of the air
 can  be used to relate  the actual evaporation to a  usefully  defined  potential evapora-
 tion.
 68-69 :02D-004
 THE  R  INDEX FOR  PLANT  WATER  REQUIREMENT,
 Yao, A.  Y. M.
 Environmental Data  Service,  Silver  Springs,  Maryland.
 Agricultural Meteorology, Vol.  6, p 259-275,  1969.   12  fig,  2  tab,  7 ref.

 Descriptors:  *Evapotranspiration,  *Model  study, Land use, Soil-water-plant relation-
 ships .
 Identifiers:  *R index, Beta distribution, Kolmogorov-Smirnov  method.

 The  frequency distribution model of the monthly and  the bi-weekly R index, the ratio
 of actual evapotranspiration to potential  evapotranspiration,  is discussed and com-
 pared  with the Beta distribution.   The goodness of fit of the  Beta  distribution to
 the  R  index frequency  distribution  was tested  using  the Kolmogorov-Smirnov method for
 173  station-month and  bi-weekly curves.  For values  of R<0.95, the  Kolmogorov-Smirnov
 test specified no rejection, at the 15% level, of the hypothesis that the R index
 follows  a Beta distribution.  With  R>0.95, 36  of the 173 R index curves failed the K-
 S tests.  However,  R>0.95 has only  very limited value for most agricultural plants.
 The  probability  distribution of R can, therefore, be used as a tool to help solve the
 problems of agricultural land use capability,  long term agricultural planning, irri-
 gation project design, and agricultural drought.
68-69:02D-005
CONCEPTS OF SOIL MOISTURE AVAILABILITY AND THEIR EFFECT ON SOIL MOISTURE ESTIMATES
FROM A METEOROLOGICAL BUDGET,
Baier, W.
Canada Department of Agriculture, Plant Research Institute, Ottawa, Ontario.
Agricultural Meteorology, Vol. 6, p 165-178, 1969.  3 tab, 5 fig, 13 ref.

Descriptors:  *Soil moisture, *Evapotranspiration, *Moisture availability, *Meteor-
ology, Meteorological data. Evaporation, Transpiration.
Identifiers:  *Versatile soil moisture budget.

Soil moisture measurements by means of Colman electrical resistance blocks over 10
years were used to test the effect of various relationships between plant-available
soil moisture (SM) and the ratio of actual  (AE) to potential (PE) evapotranspiration
on soil moisture estimates obtained by the Versatile Budget.  Depending on the type
of relationship used, correlation coefficients  (ranging from 0,76 to 0.85) between
5-day means of SM observations and estimates differed significantly and mean errors
varied from 3% to 39% of the observed seasonal means.  Under the local experimental
conditions, a linear relationship between SM and AE/PE gave estimates most closely
related to the observations.  The results suggest that when a realistic SM vs. AE/PE
relationship is used in the Versatile Budget, a precision of the estimates comparable
to the error involved in measuring soil moisture in the field by conventional methods
can be achieved.

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 68-69:020-006
 EVAPORATION FROM A SIMULATED SOIL SHRINKAGE CRACK,
 Adams, J. E.,  Ritchie, J. T., Burnett, E., and Fryrear, D. W.
 Agricultural Research Service, Temple, Texas.
 Soil Science Society of America Proceedings, Vol. 33, No. 4, p 609-613, July-August,
 1969.  2 tab,  4 fig, 6 ref.

 Descriptors:   *Evaporation, *Evaporation control, *Mulching, Water conservation.
 Identifiers:   *Soil shrinkage crack.

 A simulated soil shrinkage crack, 46 cm wide and 62 cm deep, was constructed in such
 a manner that  depth could be varied by 15.2 cm increments and width could be adjusted
 between 10 and 70 mm by 20 mm intervals.  The walls of the crack were lined with por-
 ous ceramic plates connected to a water supply maintained at -5 mb potential.  The
 simulated crack was installed in the floor of a laboratory wind tunnel located in a
 controlled environment room maintained at 24.0 - 1.5C air temperature and 43 ± 3%
 relative humidity.  Evaporation from the simulated crack walls (ceramic plates) was
 determined for all combinations of four crack widths  (10, 30, 50, and 70 mm), three
 crack depths (30, 45, and 60 cm) and five windspeeds  (0, 2.2, 4.5, 6.7, and 8.9 m
 sec-1).  Total water loss  (evaporation) from the walls of the simulated crack increa-
 sed as any one or all of the three variables (windspeed, crack depth, or crack width)
 increased.  These three variables accounted for 99.1% of the variability in total
 evaporation from the crack walls.  Turbulent air movement within the simulated crack
 was the major  factor affecting the evaporation.  Both straw and gravel mulches re-
 duced evaporation from the crack walls 85 to 90% with no wind and about 60% at 8.9 m
 sec--'- windspeed.  The results suggest that evaporation from soil shrinkage  cracks
 may be reduced by closer plant or row spacing or by surface residues such as trash
 and clod mulches.
68-69:02D-007
SOIL-WATER DIFFUSIVITY VALUES BASED UPON TIME DEPENDENT SOIL-WATER CONTENT DISTRIBU-
TIONS,
Cassel, D. K., Warrick, A. W., Nielsen, D. R., and Biggar, J. W.
California University, Davis, Department of Water Science and Engineering.
Soil Science Society of America Proceedings, Vol. 32, No. 6, p 774-777, December 1968
7 fig, 3 tab, 7 ref.

Descriptors:  *Soil-water infiltration, *Diffusion
Identifiers:  Bulk density.

A laboratory method based upon time dependent soil-water content distributions is
presented for calculating isothermal soil-water diffusivity values for soils at 5 to
15 volume percent water.  The redistribution of water within sealed soil columns was
monitored by gamma-radiation attenuation at approximately 100 to 1,000 hour intervals
over a period exceeding 3 months.  Diffusivity values from numerical integration of
the diffusion equation were obtained easily and compared favorably with those of pre-
vious investigators.
68-69:02D-008
PLANT GROWTH-EVAPOTRANSPIRATION RELATIONS FOR SEVERAL CROPS IN THE CENTRAL GREAT
PLAINS,
Hanks, R. J., Gardner, H. R., and Florian, R. L.
Utah State University, Logan.
Agronomy Journal, Vol. 61, No. 1, p 30-34, January-February, 1969.  5 fig, 1 tab,
9 ref.

Descriptors:  *Evapotranspiration, *Evaporation, *Lysimeters, *Transpiration, Wheat,
Oats, Millet, Water conservation, Water utilization, Dry land farming.
Identifiers:  Great Plains.

Lysimeters, which eliminated runoff and percolation below 90 cm, caused about 10 cm
of additional water to be available for growth of grain sorghum in 1967.  This addi-
tional water doubled yields, with an increase in evapotranspiration of only 50%.
Evaporation from soil in the lysimeter was only 32% of the evapotranspiration, com-
pared with 50% for the soil surrounding the lysimeter.  Evaporation from the soil
within a winter wheat crop during the actively growing period in the spring, was
estimated to be 15 and 37% of evapotranspiration for 1966 and 1967 respectively.

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 Evaporation from the soil within the actively growing crop was  estimated  to be  34 and
 20% of the evapotranspiration for oats and millet,  respectively.   Estimates of  the
 amount of water evaporated from the soil within a crop allowed  for estimation of
 transpiration from measurements of evapotranspiration.  This  data  indicate that pro-
 duction and transpiration are directly related in this dryland  area as de Wit  (3)
 suggests.
 68-69:02D-009
 IN SITU MEASUREMENT OF SOIL AND PLANT  LEAF WATER POTENTIAL,
 Rawlins, S.  L.,  Gardner,  W. R., and Dalton,  F.  N.
 U.S.  Salinity  Laboratory,  Soil  and Water  Conservation  Research Division, Agricultural
 Research Service,  Riverside,  California.
 Soil  Science Society of America Proceedings,  Vol.  32,  No.  4, p 468-470, July-August,
 1968.   2 fig,  6  ref.

 Descriptors:  *Transpiration, *Tensiometers.
 Identifiers:  *Soil water  potential, Thermocouple  psychrometer.

 For a  pepper plant (Capsicum frutescens L.)  growing  in a greenhouse,  soil water po-
 tential was  measured with  tensiometers and a  thermocouple  psychrometer, plant water
 potential  was  inferred from a calibrated  beta gauge, and transpiration was measured
 by weighing  the  soil-plant system.   Water moved through the transpiration stream in
 the direction  of the gradient of the water potential.   Regardless of  the distribution
 cf water in  the  soil,  transpiration was unaffected by  soil water content until it
 dropped to a value corresponding to -6 to -8  bars  water potential.  Below this water
 content, transpiration decreased linearly with  soil  water  content to  a soil water po-
 tential of -37 bars.   At  this time the plant  water potential was below -50 bars and
 the transpiration  rate was near zero.  After  irrigation the plant regained full
 turgor.
 68-69 :02D-010
 A PHYSICAL ANALYSIS  OF DIURNAL  TEMPERATURE REGIMES IN CLEAR AND TURBID WATER LAYERS:
 A PROBLEM IN RICE CULTURE,
 Rose, C. W., and Chapman, A. L.
 CSIRO,  Division of Land Research, Canberra, A.C.T., Australia.
 Agricultural Meteorology, Vol.  5, p  391-409,  1968.  9 fig, 2 tab, 18 ref.

 Descriptors:  *Rice,  *Turbidity, *Water temperature, *Solar radiation, Radiation,
 Diurnal distribution, Irrigation, Thermoperiodism, Evaporation control.
 Identifiers:  Thermal transport.

 Previous work has shown that water temperature is an important factor in the estab-
 lishment of a rice crop by broadcasting pregerminated seed into flooded fields.  In
 the tropics, water temperatures often exceed  the optimum for this method of estab-
 lishment.  At Coastal Plains Research Station (12°33'S 131°20'E) near Darwin, N.T.,
 Australia, a rice field environment  was simulated using tanks.  Diurnal temperature
 profiles were measured in 10- and 30-mm layers of clear water with and without an
 evaporation suppressant, and turbid  water, for the months of December and June.  The
 patterns of temperature in clear and turbid water were consistently different at both
 times of the year.  Marked temperature gradients  (up to l°C/cm) occurred by day in
 turbid water, with maxima at the air-water interface, but gradients in clear water
 were invariably very  small.  The physical theory of radiation absorption and thermal
 transport in a water  layer is presented and used to interpret the observations of
 temperature.  A crucial factor  in the interpretation relates to the conditions which
 govern the onset of convective motion.  The analysis indicates that the temperature
 in clear water layers will be uniform throughout at all times and for all depths used
 in rice culture.  The same will be true in turbid water at night, but during the day
 temperature will decrease with depth.
68-69:020-011
VAPOR LOSSES THROUGH SOIL MULCH AT DIFFERENT WIND VELOCITIES,
Acharya, C. L., and Prihar, S. S.
Punjab Agricultural University, Hissar, India, Department of Soils.
Agronomy Journal, Vol. 61, No. 5 p 666-668, September-October, 1969.  3 tab, 3 fig,
6 ref.

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Descriptors:  *Soil moisture, *Mulching, *Evaporation control, *Wind velocity, Water
vapor.
Identifiers:  Mulch porosity, Mulch thickness.

Rates of water vapor loss, E, through surfactant treated soil mulch of varying por-
osity and thickness were measured in pots exposed to various wind velocities under a
wide range of evaporative demand.  Empirical values of constant 'BD' obtained from
the relation Eo/E = 1+BDZn  (where Eo is the potential evaporation from the medium and
Zn is the thickness of mulch) were expressed in terms of wind velocity (X-^) and por-
osity of mulch (X2) .  Multiple regression of the type BD = q + qj_X-^ + q2x2 was used
to express BD as a function of wind velocity and porosity of mulch within the range
of linearity of the relation Eo/E = f (Zn) .
68-69:020-012
DETERMINATION OF THE SEASONAL AND MONTHLY EVAPORATION NORMALS FROM AGRICULTURAL
FIELDS FROM OBSERVATIONS AT A NETWORK OF STATIONS,
Kuz'min, P. P., Fedorov, S. F. ,  and Pomytkin, B. A.
State Hydrological Inst., Leningrad, USSR.
Trans, from Trudy GGI, No. 151,  p 12-29, 1968.  Soviet Hydrology, Selected Paper
No. 3, p 206-221, 1968.  3 fig,  19 ref, 5 append.

Descriptors:  *Evaporation, *Evapotranspiration, Humidity, Climatology, Energy bud-
get, Meteorology, Soil moisture, Plants, Crops, Vegetation effects.
Identifiers:  *USSR.

A method is given for determining long-period average seasonal and monthly evapora-
tion from agricultural fields during the warm period, May-September,  The method
uses an empirical graphic relationship between crop evaporation coefficient and the
radiational aridity index.  Calculations of evaporations are tabulated and compared
with evaporimeter measurements in all the major geographic regions of the USSR.
68-69.-02D-013
SIMULATION OF EVAPORATION FROM CONSTANT SOURCE WITH FINITE AREAS,
Shih, Chau, and Dracup,  John A.
California University, Los Angeles.
Water Resources Research, Vol. 5, No. 1, p 281-290, February 1969.  8 fig, 1 tab,
9 ref.

Descriptors:  *Evaporation, *Computer models. Mass transfer, Simulation analysis,
Heat budget, Hydrologic budget, Digital computers, Analog computers, Resistance net-
works, Mathematical models. Convection, Diffusion, Lakes, Reservoirs, Winds, Solar
radiation.
Identifiers:  *Hybrid computer methods.

Evaporation from finite areas with constant sources is determined by simulating the
mass transfer equation.   The equation of mass transfer in a turbulent atmosphere
describes the movement of mass, water vapor, and momentum.  The process of transfer-
ring water vapor by evaporation from a constant source can be analyzed by the solution
of this diffusion equation.  A hybrid computer simulation method to solve the three-
dimensional nonuniform diffusion equation is described.  The proposed technique can
handle any geometric configuration of lakes and reservoirs.  Using a finite differ-
ence method, the partial differential equation is transformed into a set of algebraic
equations and the node equations of a passive resistance network plane makes the hy-
brid computer simulation technique applicable to solve problems of this type.  A ver-
tical plane, perpendicular to the direction of the wind, is simulated by a passive
resistance network.  The problem is solved by moving the vertical plane in the direc-
tion of the wind.  Obtaining the solution using a simulation technique involves a
repetitive process of observing voltages on the simulation network.  The entire pro-
cess is performed in the hybrid computer system using the digital computer as the
control.  This is a general method available to analyze the evaporation phenomena
using a mathematical solution of the diffusion equation.

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 68-69 :02D-014
 EVAPORATIVE COOLING OF HEATED IRRIGATION WATER BY SPRINKLER APPLICATION,
 Cline,  J.  N., Wolf, M. A.,  and Hungate,  F.  P.
 Battelle Memorial Institute,  Richland,  Washington.
 Water Resources Research,  Vol. 5,  No.  2, p  401-406,  April  1969.   1  fig,  3  tab,  20  ref.

 Descriptors:  *Heated water,  *Sprinkler irrigation.  Temperature  control, Cooling,
 Irrigation, Evaporation,  Crop production.
 Identifiers:  * Impact temperature,  Relative humidity,  Nozzle pressure. Evaporative
 cooling.

 Heated  water was cooled rapidly to  impact temperatures that produce  optimum growth in
 plants  by  applying the water  with  a standard irrigation sprinkler.   Maximum cooling
 was observed nearest the  sprinkler, where the  smallest droplets  were measured,  and
 temperatures and mean diameters generally increased  with distance from the source.
 Impact  temperatures of the  water droplets approached but did not reach wet bulb tem-
 peratures.   Water as hot  as 50 deg  C was cooled  to droplet temperatures of 25 deg C
 or less when the sprinklers were operated in an  associated arid  climate and at  line
 pressures  greater than 25 psi.  A  theoretical  treatment correlated well with one
 selected set of experimental  data  and with  predicted cooling rates  for specified
 droplets in several typical atmospheric  conditions and one untypical condition  for an
 arid climate.   Only under the condition  of  high  relative humidity at a given ambient
 temperature does it appear  that cooling  might  be  insufficient to produce usable
 sprinkler water from 50 deg C supply water  for crop  production.
 68-69:020-015
 A MODEL FOR  SIMULATING  SOIL WATER REGIME  IN ALTERNATING FALLOW-CROP SYSTEMS,
 Fitzpatrick, E. A.,  and Nix,  H. A.
 Commonwealth Scientific and Industrial Research Organization, Canberra, Australia,
 Div.  of Land Research and Regional  Survey.
 Agricultural iMeteorology, Vol.  6, No. 5,  p 303-319, September 1969.  8 fig, 1 tab,
 36 ref.

 Descriptors:   *Model studies,  *Evaporation, *Evapotranspiration, *Soil water, *Fal-
 lowing, crop  production, Semiarid climates, Cotton, Sorghum, Wheat, Water loss, Water
 balance, Meteorological data,  Climatology, Soil-water-plant relationships.
 Identifiers:   *Soil water reserves, Agronomic practices, Queensland, Australia.

 A set  of simple working functions depicting evaporative loss from an alternating
 fallow-crop  system was  used in a model for simulating soil water regime in sub-humid
 to semi-arid central Queensland.  Despite inadequacies in the data, the model closely
 simulated changes over  time in the  soil water regime.  This was achieved by using
 distinctive  functions for fallowed  and cropped intervals and by making evapotranspir-
 ation  rates  dependent upon status of available soil water and stage of crop develop-
 ment.  Data  were sufficient to  allow formulation of functions for cotton, sorghum,
 and wheat.   The model makes provision for future refinements in data and appears
 promising as a basis for assessing  effects of varied agronomic practices on avail-
 able soil water reserves.
68-69 :02D-016
THE EVAPOTRANSPIRATION COMPONENT OF A PASTORAL EXPERIMENTAL CATCHMENT,
Dunin, F. X.
Soil Conservation Authority, Kew, Australia.
Journal of Hydrology, Vol. 7, No. 2, p 147-157, January 1969.  1 fig, 5 tab, 3 ref.

Descriptors:  *Evapotranspiratior., *Hydrologic budget, Mathematical models, Water
balance, Antecedent precipitation, Runoff, Moisture stress, Rainfall-runoff rela-
tionships. Demonstration watersheds, Model studies, Soil water movement.
Identifiers:  *Australia, Potential evapotranspiration, Parwan Experimental Area
(Australia).

The amount of evapotranspiration occurring from a pastoral catchment was determined
by an assessment of the hydrologic balance within the catchment.  A measure of the
variable for changes in water content was achieved by the evaluation of soil storage
deficits antecedent to runoff events.  Thus, the intervals of time for the determin-
ation of the amounts of evapotranspiration were confined to periods between runoff
events. For tnose intervals when the index of topsoil moisture stress did not exceed
a pF value of 3.5, a ratio of one existed between measured evapctranspiration and

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 the  index  of potential evapotranspiration.  With the use of this ratio in conjunction
 with the soil moisture record, variations in rates of evapotranspiration were pres-
 ented for  the years 1963  to  1966.  Such data indicated that the prevailing land-use
 was  inefficient  in its consumption of water.
 68-69:020-017
 PREDICTING EFFECTS OF WATER  SHORTAGE ON CROP YIELD,
 Stewart, J.  Ian, and Hagan,  Robert M.
 California University, Davis, Dept of Water Science and Engineering.
 Journal of the  Irrigation and Drainage Division, ASCE, Vol. 95, No. IR1, Proc Paper
 6443, p 91-104, March 1969.  9 fig, 14 ref.

 Descriptors:  *Crop production, *Water shortage, *Water utilization, *Water alloca-
 tion  (Policy),  *Planning, Evapotranspiration, Alfalfa, Sorghum, Wheat,  Soil moisture,
 Water management, Precipitation  (Atmospheric), Irrigation efficiency, Moisture defi-
 cit, Water supply, Data collections.

 This paper discusses relationships existing between water use, expressed as evapo-
 transpiration,  and yields of alfalfa, wheat and grain sorghum.  Data assembled from a
 number of sources, was used  to tentatively formulate water production functions in
 both absolute and relative forms.  A detailed hypothetical example of use of such a
 function for water allocation and management planning for maximization  of wheat pro-
 duction during  a water shortage was given.  The example showed the disproportionate
 importance which can be attached to stored soil moisture and in-season  precipitation
 when maximization of total production is the goal.  Conclusions were basically that
 definition of water use-yield relationships can be done for certain crops from exper-
 imental data, and that the functions thus produced would greatly assist planners at
 all levels in making water allocation and management decisions, particularly in sit-
 uations of water shortage.
68-69:020-018
THE EFFECT OF ALBEDO ON THE EVAPOTRANSPIRATION RATE,
Seginer, I.
Cornell University, Ithaca, N.Y.
Agricultural Meteorology, Vol. 6, p 5-31, 1969.  12 fig, 3 tab, 20 ref.

Descriptors:  *Evapotranspiration/ *Irrigation, *Albedo, *Radiation, Energy budget,
Evaporation, Heat flow, -Energy balance, Model studies.
Identifiers:  Long wave radiation.

The problem was to evaluate the possibility of reducing the evapotranspiration of an
irrigated field by increasing its reflectivity to incoming radiation.  A numerical
computation approach was used to solve the differential equations governing the
transfer phenomena in a horizontally homogeneous atmospheric boundary layer and under-
lying soil.  A few preliminary tests showed that although wind velocities were not
accurately predicted, the effect of such inaccuracies on the energy budget results
was not significant.  Comparisons of calculated results for fields with natural
albedo  (0.25) and fields with albedo artificially increased to 0.40, indicated the
following:  (1) Under a clear sky, the relative reduction in net radiation due to the
treatment was about 30%, as compared with only 20% reduction in the solar radiation
absorbed at the surface; (2) The major factors affecting the saving of water were
the albedo and the wetness of the surface.  Wind, surface roughness and thermal
stratification were of only secondary importance; (3) The saving in water due to the
treatment was calculated to be roughly 30% for all wetness conditions.
68-69:020-019
CONTROLLING TRANSPIRATION IN ASPEN WITH PHENYLMERCURIC ACETATE,
Hart, G. E., Schultz, J. D., and Coltharp, G. B.
Utah State University, Logan.
Water Resources Research, Vol. 5, No. 2, p 407-412, April 1969.  3 fig, 3 tab,
10 ref.

Descriptors:  *Evapotranspiration control, *Transpiration control, Stomata, Water
conservation, Forests, Water yield improvement, Watershed management, Forest manage-
ment, Water management  (Applied).
Identifiers:  Phenylmercuric acetate, Aspen trees.

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 A 0.0001 M spray of phenylmercuric acetate was applied by helicopter to  part  of  an
 aspen stand in northern Utah in June,  1967.  The natural fluttering action  of the
 aspen leaves facilitated delivery of the spray to the stomata-bearing underside  of
 the leaves.  Nine days after treatment,  stomata width on treated  trees averaged  2.4
 microns as compared with 4.0 microns measured on untreated trees.   Heat  pulse meas-
 urements indicated reduction in daylight sap velocity from 11  cm/hr to 6 cm/hr.
 Seasonal soil moisture depletion was not significantly affected,  although the pattern
 of water usage was delayed for about 6 weeks on the treated area.
 68-69:020-020
 THE CLIMATOLOGY OF SOIL MOISTURE,  EVAPORATION,  AND  NON-MOISTURE  STRESS DAYS FOR CORN
 IN IOWA,
 Dale,  Robert F.
 Environmental Science Services Administration,  Rockville, Maryland.
 Agricultural Meteorology,  Vol. 5,  No.  2,  p 111-128,  March 1968.   12  fig,  7 tab, 12
 ref.

 Descriptors:  *Climatology,  *Corn  (Field),  *Crop  production,  *Soil moisture, *Evapo-
 ration, Moisture availability, Moisture  stress, Evapotranspiration,  Weather, Precipi-
 tation (Atmospheric),  Iowa,  Corn Belt, Estimating,  Phenology,  Soil-water-plant rela-
 tionships,  Variability.
 Identifiers:  *Potential evapotranspiration,  *Non-moisture  stress.

 The study  is concerned with  the possibility of  utilizing for  regional agricultural
 planning a  method which considers  the  interaction upon  corn crops of potential evapo-
 transpiration,  soil moisture,  and  ease of extraction of available water.  Climatology
 of the number of days  with no  moisture stress in  the critical  growth period of corn
 is given for four Iowa locations.  Climatology  of the input variables is  described
 for these  same  four stations.   Input variables  consist  of evaporation, precipitation,
 and soil moisture under  corn.   Using the  non-stress  day climatology  it was demon-
 strated that areas of  higher than  average precipitation had a  higher frequency of
 unfavorable  weather and  lower  corn yields caused  by  moisture  stress.
 68-69 :02D-021
 USE OF ATMOMETERS  IN ESTIMATING  EVAPOTRANSPIRATION,
 Shannon, John W.
 California Dept of Water Resources,  Sacramento.
 Journal of the Irrigation and Drainage Division, ASCE, Vol. 94, No. IRS, Proc Paper
 No. 6120, p 309-320, September 1968.

 Descriptors:  *Atmometers,  Instrumentation, Evaporation, *Climatic data, *Evapo-
 transpiration, Evaporation  pans, Water requirements, Data collections, Energy,
 *Monthly, *Seasonal, Water  loss.
 Identifiers:  Evaporative demand, Crop coefficients.

 Studies conducted by the California  Department of Water Resources during the past 10
 years show that Livingston  black and white spherical atmometers provided a practical
 means of estimating monthly and  seasonal evapotranspiration.  The difference of evap-
 oration  between the black  and white atmometers was affected primarily by short wave
 energy, whereas evaporation from either the black or white atmometer provided an
 index of the total amount of energy  available for evapotranspiration.  Various stud-
 ies were made, the results  of which  indicated that the type of background has little
 effect upon the difference  in evaporation between the black and white atmometers.
Monthly crop coefficients were developed for some of the principal crops in the
Central Valley of California, which  provided evapotranspiration estimates consistent-
 ly as good as or better than could be obtained using coefficients developed from
United States Weather Bureau Class A evaporation pan data.
68-69 :02D-022
POTENTIAL EVAPOTRANSPIRATION AS INFLUENCED BY WIND,
Skidmore, E. L., Jacobs, H. S., and Powers, W. L.
Kansas State University, Manhattan.
Agronomy Journal, Vol. 61, No. 4, p 543-546, July-August, 1969.  6 fig, 1 tab, 19
ref.
                                      10

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Descriptors:  Evaporation, *Evapotranspiration, *Winds, Wind velocity, Wind speed,
Agronomy, Crops, Water requirements. Great Plains, Effects, Agriculture, Energy
balance, Hydrology, Bibliographies, Soil science.
Identifiers:  *Potential evapotranspiration, Hydrologic models,Net radio-
meter. Van Bavel method.

The contribution of wind to calculated potential evapotranspiration was investigated
with applications for the climate of the Great Plains.  A revised combination model
proposed by van Bavel for computing instantaneous potential evapotranspiration was
used.  The model contains 2 terms that are expressions for the portions of potential
evapotranspiration primarily caused by net radiation and wind.  With ambient water
vapor pressure 20 mb, temperature 30 deg C, wind 2, 4, and 6 m/sec at 2 m with a
roughness length of 1 cm, the contribution of wind-dominant term to evaporation from
a wet surface is 0.15, 0.30, and 0.45 mm/hr, respectively.  At 10-mb vapor pressure
and the same temperature, the corresponding evaporation rates are 0.22, 0.43, and
0.65 mm/hr.  On representative and consecutive nonwindy and windy days at Manhattan,
Kansas  (average daily windspeeds at 45 cm were 0.88 and 2.26 m/sec), the wind-domin-
ant term contributed 33 and 113% respectively, as much as the radiation-dominant term
to the total calculated potential evapotranspiration.  For these 2 days, the ratio of
potential evapotranspiration to net radiation was 0.98 and 1.60.
68-69:020-023
EVAPOTRANSPIRATION AND MICROCLIMATE OF IRRIGATED PASTURES AND ALFALFA UNDER HIGH
ALTITUDE CONDITIONS,
Burman, R. D., and Loudon, T. L.
Wyoming University, Laramie, Dept of Agricultural Engineering.
American Society of Agricultural Engineers, Transactions, Vol. 11, No. 1, p 123-125,
January-February, 1968.  6 fig, 6 tab, 5 ref.

Descriptors:  *Evapotranspiration, *Microclimatology, *Irrigated land, *Irrigation
effects, *Pastures, Alfalfa, Wheatgrasses,  Arid lands, Wyoming, Altitude, Air circul-
ation, Cloud cover, Crop response, Energy budget, Solar radiation.
Identifiers:  *Energy-balance components, *Farson Pilot Farm, Wyoming, *Cool steppes,
*Red Desert, Wyoming, Eden Project, Ryegrasses.

Studies were undertaken in 1962-1966 to investigate evapotranspiration and micro-
climate of high-altitude irrigated pastures.  It was found that evapotranspiration
from ryegrass-alfalfa pastures was higher than evapotranspiration from wheat-grass-
alfalfa pastures, except for a 1-hr midday period when it was lower for the ryegrass-
alfalfa mixture.  The greatest evapotranspiration difference between crops occurred
in the afternoon.  Crop evapotranspiration was influenced considerably more by sky
conditions than by application of irrigation.  Energy-balance components were much
higher in bright sunshine than under cloudy skies.  Air over the pasture was unstable
until late afternoon, with most of the evapotranspiration occurring during the period
of instability.
68-69:020-024
PAN EVAPORATION AND EVAPOTRANSPIRATION FROM CLIMATIC DATA,
Christiansen, Jerald E.
Utah State University, Logan.
Journal of the Irrigation and Drainage Division, ASCE, Vol. 94, No. IR2, Proc Paper
No. 5988, p 243-265, June 1968.  13 tab.

Descriptors:  *Evaporation pans, *Evapotranspiration, *Climatic data, *Mathematical
models. Equations, Data collections, *Analytical techniques, Temperature, Solar
radiation, Wind velocity, Humidity, Elevation.

A formula was developed at Utah State University for estimating pan evaporation from
extraterrestrial radiation and climatic data.  This formula utilizes climatic data
of the type most readily available.  Tables are presented to simplify the application
of the formula where electronic computers are not used.  Three formulas for estimat-
ing evapotranspiration for several agricultural crops using as the principal para-
meters either extraterrestrial radiation, pan evaporation or measured incident radia-
tion, together with climatic data, were also presented.  The planning and design of
irrigation systems in arid regions requires, at the outset, an estimate of water
requirements which this formula can help to supply.
                                     11

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 68-69 :02D-025
 ANTITRANSPIRANTS RESEARCH AND ITS POSSIBLE APPLICATION IN HYDROLOGY,
 Davenport, David C., Hagan, Robert M.,  and Martin,  Paul E.
 California University, Davis.
 Water Resources Research, Vol. 5, No. 3, p 735-743, June 1969.   4  fig,  1  tab,  33  ref.

 Descriptors:  *Transpiration control, *Water conservation, Chemcontrol, Stomata,  Wat-
 er yield, Water management (Applied), Watershed management.
 Identifiers:  *Antitranspirants.

 Research on antitranspirants may have application in increasing the yield of water
 from watersheds by reducing transpirational losses  from vegetation under  certain  en-
 vironmental conditions.   There are 3 broad groups of antitranspirants:  (1)  reflecting
 materials that decrease  the heat load on the leaf,  (2)  film-forming materials  that
 hinder  the escape of water vapor from the leaf,  and (3)  stomata-closing materials
 that increase stomatal resistance.  Antitranspirants are most effective in decreasing
 transpiration when other resistances in the passage of water to the roots,  through
 the plant, and to the atmosphere  are not great,  when there is good coverage of the
 stomatal bearing leaf surfaces (except  for reflecting materials),  when new foliar
 growth  following treatment is minimal,  and when optimum concentrations and applica-
 tion rates are used.
 68-69:020-026
 AN INDEX OF  CROP WATER STRESS RELATED TO WHEAT  AND  GRAIN  SORGHUM  YIELDS,
 Nix,  H.  A.,  and  Fitzpatrick,  E.  A.
 CSIRO, Canberra  (Australia),  Division of Land Research  and  Regional  Survey.
 Agricultural Meteorology,  Vol.  6, No.  5,  p 321-337,  September  1969.   4  fig,  4  tab,
 21 ref,  3 append.

 Descriptors:   *Moisture stress,  *Crop production, *Evapotranspiration,  *Soil-water-
 plant relationships,  *Soil water, Moisture deficit,  Climatic data, Rainfall, Plant
 physiology,  Wheat,  Sorghum, Environmental effects,  Data collections,  Regression
 analysis,  Phenology.
 Identifiers:   *Stress index,  *Queensland, Australia.

 Soil-water regimes  for wheat  and grain sorghum  were  studied in  experiments in  central
 Queensland.  Analysis of the  ratio  of estimated actual  to potential  evapotranspira-
 tion  at  defined  intervals  of  growth for both crops  revealed a critical  growth  period
 from  ear emergence  to early grain development.  Ratios  calculated for this 'critical1
 period correlated more closely with yield than  other  indices used to  characterize
 crop  water environment.  A simple index incorporating available soil water supply
 and potential  evaporative  demand gave  highly significant correlations with yields.
 This  index accounted  for 60-83%  of  the yield variation  within the different  varieties
 under study.   After checking  these  findings against wheat yield data  in Queensland
 for the  1952-1965 period,  it  would  appear than  intra-seasonal and year-to-year varia-
 tion  in  yield  is largely a function of anthesis date  in relation to  the then pre-
 vailing  environmental moisture stress.
68-69:020-027
EVAPOTRANSPIRATION AS AFFECTED BY PLANT DENSITY AND WATER-TABLE DEPTH,
Stewart, E. H., Browning, J. E., and Burt, E. 0.
Plantation Field Laboratory, Fort Lauderdale, Florida.
Transactions of the American Society of Agricultural Engineers, Vol. 12, No. 5,
p 646-647, September-October 1969.  3 fig, 1 tab, 3 ref.

Descriptors:  *Evapotranspiration, *Water balance, *Bermudagrass.
Identifiers:  *Florida.


Studies were made to determine the relation of evapotranspiration to percentage of
plant cover and depth to water table for use in water budget studies.  A 3-year dif-
ferential water-table study was made using Tifway bermudagrass planted in 12 non-
weighing evapotranspirometers.  The installations consisted of 12 waterproof rectan-
gular tanks, 5ft deep, each having a plot area of approximately 1/1000 acre.  Plant-
cover studies were made using 0-, 1/3-, 2/3-, and full-sod cover treatments in three
replicates.  A modified randomization of treatments was used so that the three rep-
licate plots assigned to each of the four plant-cover treatments included the three
                                      12

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differential water-table level plots used in the previous study.  The plant cover
study was a 3-year study with depth to water-table maintained at a depth of 24 in.
the first year, 36 in. the second, and 12 the third,  A linear relationship exists
between degree of plant cover and annual evaportranspiration of Tifway bermudagrass
grown on Arzel fine sand with 12-, 24-, and 36-in. water tables.  Evapotranspiration
increased with sod cover at water-table depths of 24 and 36 in., but decreased slight-
ly for water table depth of 12 in.  The ratio between evapotranspiration from no sod
or partial sod and full sod was related to the depth to water table and the amount,
frequency and distribution of rainfall.
68-69:02D-028
ROLE OF EVAPORATION IN THE MIGRATION OF SALTS INTO THE ATMOSPHERE,
Nemeryuk, G. Ye.
Groskiy Agricultural Institute, Ordzhonikidze.
Soviet Hydrology:  Selected Papers, No. 6r p 618-625, 1969.  7 tab, 8 ref.

Descriptors:  *Evaporation, Evapotranspiration, Transpiration, Sublimation, *Salts,
*Chlorides, Chemistry of precipitation, *Atmosphere, Sea water.
Identifiers:  *Hydrochemistry.

The purpose of this study is to verify the validity of the assumption that salts are
removed during evaporation from the water surface in relation to the problem of the
origin of salts found in atmospheric precipitation.  The ion composition of vapor of
solutions was studied.  The migration of salts with water vapor was established in
two ways.  First, an isothermal distillation of Na2C03, Na2S04, NaCl, and CaCl2 solu-
tions was accomplished at room temperatures in a closed space in the laboratory in
the presence of hygroscopic substances.  Tests were run upon completion of the exper-
iments to determine the volumes of salts transported.  In the.field, vapor from nat-
ural soil and plant solutions was collected in chambers where the vapor condensed on
a surface cooled with dry ice.   Upon completion of the experiment, a chemical analy-
sis of the condensates was performed according to recommended methods.  Evaporation
is an important link in salt exchange through the atmosphere under natural conditions.
Migration of salts with water vapor differs from the mechanism by which salts enter
the atmosphere with sea spray.   The reason for the migration of ions with water vapor
is their hydration and apparently also exchange adsorption between liquid and gaseous
phases .
68-69:020-029
DEVELOPING A PHYSICAL-CHEMICAL MODEL FOR A PLANT GROWTH SYSTEM,
Chen, L. H., Huang, B. K,, and Splinter, W. E.
North Carolina State University, Raleigh, Dept of Biological and Agricultural Engi-
neering.
Transactions of the American Society of Agricultural Engineers, Vol. 12, No. 5,
p 698-702, September 1969.  8 fig, 9 ref.

Descriptors:  *Model studies, *Plant growth, Growth rates, Plant growth substances.
Plant Physiology, *Photosynthesis, Energy conversion, Respiration.

A model is developed which describes plant growth as a function of photosynthesis
and respiration.  The modeling of plant growth was considered essential for systems
engineering of agricultural production.  A functional relationship between photosyn-
thesis, respiration and growth was developed.  The model showed considerable promise,
the general relationship between growth rate constant and each environmental factor
were conformable to experimental results.
68-69:020-030
PLANT GROWTH-EVAPOTRANSPIRATION RELATIONS FOR SEVERAL CROPS IN THE CENTRAL GREAT
PLAINS,
Hanks, R. J., Gardner, H. R., and Florian, R. L.
Utah State University, Logan, Dept of Soils and Meteorology.
Agronomy Journal, Vol. 61, No. 1, p 30-34, January-February 1969.  5 fig, 1 tab, 9
ref.

Descriptors:  *Evaporation, Lysimeters, Transpiration, Crops, Runoff, Percolation,
Sorghum, Wheat.
Identifiers:  Great Plains.


                                      13

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Lysimeters, which eliminated runoff and percolation below 90 cm, caused about 10 cm
of additional water to be available for growth of grain sorghum in 1967.  This addi-
tional water doubled yields, with an increase in evapotranspiration of only 50 percent.
Evaporation from soil in the lysimeter was only 32% of the evapotranspiration, com-
pared with 50%  for the soil surrounding the lysimeter.  Evaporation from the soil
within a winter wheat crop during the actively growing period in the spring, was es-
timated to be 15 and 37% of evapotranspiration for 1966 and 1967 respectively.  Evap-
oration from the soil within the actively growing crop was estimated to be 34 and
20% of the evapotranspiration for oats and millet, respectively.  Estimates of the
amount of water evaporated from the soil within a crop allowed for estimation of
transpiration from measurements of evapotranspiration.  This data indicate that pro-
duction and transpiration are directly related in this dryland area as de Wit (3)
suggests.
                                      14

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                                     SECTION III


                   WATER CYCLE - STREAMFLOW AND RUNOFF (Group 02E)


68-69:02E-001
A METHOD OF ANALYZING TRANSIENT FLUID IN MULTILAYERED AQUIFERS,
Javandel, Iraj, and Witherspoon, Paul A.
Pahlavi University, Shiraz, Iran.
Water Resources Research, Vol. 5, No. 4, p 856-869, August 1969.  10 fig, 13 ref.

Descriptors:  Transients, *Unsteady flow, *Aquifers, Methodology, Theis equation,
Fluid flow, *Groundwater flow, Anisotrophy, Permeability, Drawdown, Numerical
analysis, Groundwater, Pumping, Analysis.
Identifiers:  *Transient flow, Finite element method, Two-part aquifers, Boundary
conditions.

A new approach to transient fluid flow in multilayered aquifers of anisotropic sys-
tems was developed using the finite element method.  This is a numeric technique in
which an initial boundary value problem is converted to a variational problem and
applied to a discrete system of elements.  The method was used to investigate poten-
tial distributions in multilayered aquifers of finite radial extent being pumped at
constant rate using completely penetrating wells.  An analysis of 2-layer systems
with permeability contrasts of up to 100:1 indicates that at early time the drawdown
behavior can vary significantly from the Theis solution,  depending on where observa-
tions are made.  As time increases, results converge on the Theis solution, regard-
less of the permeability contrast.  A 13-layer aquifer containing either isotropic
or anisotropic layers was also examined.  Results are in general agreement with the
behavior for 2-layer systems.
68-69:02E-002
DESIGN OF RECIRCULATING IRRIGATION SYSTEMS,
Bondurant, J. A.
Agricultural Research Service, Kimberly, Idaho.
American Society of Agricultural Engineers, Transactions, Vol. 12, No. 2, p 195-198,
1969.  6 fig, 3 ref.

Descriptors:  *Runoff, *Water reuse, *Irrigation systems, *Surface irrigation, Irri-
gation efficiency, Irrigation water, Idaho, Farm equipment, Operating costs, Irriga-
tion engineering. Agricultural engineering, Equations, Arid lands, Design criteria.
Pumping plants, Cost analysis, Flow rates. Water utilization.
Identifiers:  *Recirculating irrigation systems.

Irrigation is necessary for many crops in arid or semiarid regions.  When water costs
are high or when it is desirable to control surface flow of silt and chemical contam-
inants in irrigation runoff water, a recirculation system may be considered.  When
irrigation runoff is collected it should be recirculated to a different field.  Maxi-
mum improvement in efficiency is achieved by using stored runoff water to reduce
stream size for cutback irrigation.  A design example is given for an Idaho farm of
105 irrigated acres.  A method is presented for determining amount and rates of run-
off and time and size of cutback.  Since annual operating costs depend to a large
extent on design and efficiency of the pumping installation, great emphasis is placed
on these factors.  The necessary design data are listed and the equations for design
calculations are given.
68-69 :02E-003
A COMPARISON OF NITROGEN LOSSES FROM UREA AND AMMONIUM NITRATE IN SURFACE RUNOFF
WATER,
Moe, P. G.,  Mannering, J. V., and Johnson, C. B.
Purdue University Agricultural Experiment Station, Lafayette, Indiana.
Soil Science, Vol. 105, No. 6, p 428-433, 1968.  3 fig, 3 tab, 9 ref.

Descriptors:  *Nitrogen, *Surface runoff, *Ammonium compounds, *Urea.

Small plots were established on a Zanesville silt loam having a 13% slope and a frag-
ipan at 24-34 in.  Half the plots were maintained in an established fescue sod
clipped to a height of 3-4 in. and the other half were second-year fallow plowed in


                                      15

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 mid-May and disced two times in mid-July.  Pellets of ammonium nitrate and urea were
 broadcast on the surface at rates equivalent to 400 Ibs/acre of N.   A rainfall simu-
 lator was used to apply 2% in. of water at preselected times.  Runoff was sampled at
 5-minute intervals and analyzed for ammonium, nitrate, and urea N.   Total N loss from
 all plots ranged between 2.4 - 12.7% of the applied N.  Urea was present only in run-
 off from sod plots; most of the area was rapidly hydrolyzed in the  soil.  NH4+-N was
 less susceptible to runoff loss in urea plots than ammonium nitrate plots, probably
 because urea moved more deeply into the soil with water than the highly ionized
 ammonium nitrate.
 68-69:02E-004
 GEOMETRIC SHAPING AND CONTOURING OF LAND AS RELATED TO POTENTIAL FOR SURFACE-WATER
 STORAGE,
 Doty,  C.  W.,  and Wiersma,  J.  L.
 Agricultural  Research Service,  Brookings, South Dakota.
 Amar.icar.  Society cf Agricultural Engineers, Transactions,  Vol.  12,  No.  4,  p  325-332,
 May-June,  1969.   8 fig,  3  tab,  12 ref.

 Descriptors:   *Water storage,  *Surface  runoff,  *Erosion  control,  *Water conservation,
 *Soxi  conservation,  Terracing,  Contour  farming,  Runoff,  South Dakota, Corn Belt,
 Shape,  Storage capacity,  Planting management, Crop production.
 Identifiers:   *Geometric  shaping, *Listing, *8-row bedding.

 In  the  Corn Belt 60-75% of annual runoff and 75-90% of annual erosion occurs  during
 the first  60  days of the  corn  season (planting  to  second cultivation).   Since it  is
 impossible to apply a crop canopy to the soils,  surface  configurations  on  the land
 are necessary to store water and reduce runoff.  The study was  designed to discover
 which of  six  various geometric  shapes had the greatest water-holding capacity.  This
 capacity would determine  ability to decrease runoff and  erosion.   It was concluded
 that listing  and 8-row bedding were the most beneficial  configurations,  provided  they
 were coupled  with very accurate  contouring.
 68-59:02E-005
 CHLORINATED  INSECTICIDES  IN  RUNOFF  WATER AS AFFECTED  BY  CROP  ROTATION,
 Epstein, E., and  Grant, W. J.
 Agricultural Research  Service,  Orono,  Maine.
 Soil  Science Society of America Proceedings, Vol.  32,  No.  3,  p  423-426, May-June,
 1968.   6 tab,  20  ref.

 Descriptors:   *Pesticides, *Runoff, *Rotations, Water  pollution sources, Path of
 pollutants, DDT,
 Identifiers:   Crop rotation  effects.

 The concentration and  amounts of 3  chlorinated  insecticides were  lower in runoff from
 a rotation system of potato, oats,  and  sod than under  continuous  potato cropping.
 Runoff  samples from natural  runoff  plots  were collected  following each storm, and
 the amounts of DDT, endrin,  and endosulfan were analyzed with a gas chromatograph.
 The amounts of pesticides in runoff were  small  compared  to the  amount applied.  The
 concentrations of the  insecticides  in  the runoff  (soil-water  suspension) were gener-
 ally greater than those found in the settled soil  (sludge).
68~69:02E-OC6
EFFECTS OF CULTIVATION AND GRASS ON SURFACE RUNOFF,
Dragoun, Frank J.
Agricultural Research Service, Coshocton, Ohio.
Paper No. K-28, presences at 50th Annual Meeting of American Geophysical Union,
Washington, D.C.", April 21-25, 1969.  13 p, 3  fig, 3 tab, 7 ref.

Descriptors:  * Rainfall-runoff reiationsnips,  Cultivation, ^Surface runoff, *Water
yield improvement, Grasslands, Crops, Land use. Watersheds  (Basins), Runoff, Nebraska,
Great l-'la: _"-,, Watershed management.
Idart'fiars:  Hastings, Nebraska.

More than a million acrss of marginal cropland have been, converted to permanent vege-
tation in the Great Plains, and; conversion is proposed for many more acres.  This
report presents results of research showing the effect cf drastic changes in land use


                                      16

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on watershed  surface runoff  from  4-acre watersheds near Hastings, Nebraska.  Surface
runoff was  significantly reduced  two years after converting marginal cultivated
fields to perennial grass, and was representative of runoff from native meadow after
the  third year.  Conversely,  runoff increased greatly the first year after native
meadow was  placed  in cultivation.
 68-69:02E-007
 RUNOFF VOLUME PREDICTION FROM DAILY CLIMATIC DATA,
 Knisel, Walter G., Jr., Baird, Ralph W., and Hartman, Monroe A.
 Agricultural Research Service, Riesel, Texas.
 Water Resources Research, Vol. 5, No. 2, p 84-94, February 1969.  8 fig, 9 ref.

 Descriptors:  *Rainfall-runoff relationships, *Soil moisture, *Runoff forecasting,
 Model studies, Mathematical models, Digital computers, Hydrologic budget, Discharge
 (Water), Infiltration, Inflow, Streamflow, Water balance, Evaporation, Precipitation
 intensity, Duration curves, Hydrograph analysis, Hydrographs.
 Identifiers:  Soil moisture reservoir, Runoff prediction.

 A two-soil-moisture-reservoir model is developed to improve  the estimate accuracy of
 a runoff-volume-prediction model.  Soil moisture accounting  in the two reservoirs is
 an intermediate step to runoff prediction.  A decay-type function describes the mois-
 ture depletion between days of rainfall.  The moisture depletion constant in the func-
 tion varies by season with soil moisture, pan evaporation, and mean daily temperature.
 The runoff prediction equation relates runoff to rainfall and soil moisture at the
 beginning of the storm.  Computed runoff volumes are compared with values observed on
 a 3-acre native grass-meadow watershed for an 11-year period.  Accumulated computed
 amounts for the period agree within 1% of the accumulated observed amounts.
68-69:02E-008
APPLICATION RATES AND RUNOFF IN CENTER-PIVOT SPRINKLER IRRIGATION,
Kincaid, D. C., Heermann, D. F., and Kruse, E. G.
Colorado State University, Fort Collins, Dept of Agricultural Engineering.
American Society of Agricultural Engineers, Transactions, Vol. 12, No. 6, p 790-794,
797, November-December, 1969.  9 fig, 4 tab, 4 ref.

Descriptors:  *Rates of application, *Application methods, *Sprinkler irrigation,
*Runoff, *Soil types, Irrigation systems, Irrigation practices, Irrigation design,
Irrigation efficiency, Slopes, Soil surfaces, Estimating, Data collections, Consump-
tive use, Soil water, Discharge  (Water), Infiltration.
Identifiers:  *Center-pivot sprinkler systems, *Soil intake rates, *Potential runoff,
*Actual runoff.

Application rates and expected runoff in relation to different soil types were ana-
lyzed for the center-pivot sprinkler irrigation system.  Potential runoff theory
using modified experimental intake constants was applied to field situations.
Results were compared with experimental estimates of actual runoff.  Given a certain
amount of potential runoff from a particular area, actual runoff depends on slope,
roughness of soil surface, and position with respect to other runoff areas.  Special
attention should be given to soil surface conditions and intake rates when applying
center-pivot systems to sloping lands.
6S-69:02E-009
QUICK-RETURN SUBSURFACE FLOW,
Jamieson, D. G., and Amerman, C. R.
Agricultural Research Service, Beltsville, Maryland, Hydrograph Lab.
Journal of Hydrology, Vol. 8, No. 2, p 122-136, June 1969.  1 tab, 16 ref.

Descriptors:  *Soil water movement, *Subsurface runoff, *Routing, *Surface-ground-
water relationships, Water storage, Model studies, Mathematical models, Simulation
analysis, Infiltration, Overland flow, Percolation.
Identifiers:  Quick-return subsurface flow.

One of the least understood of all hydro-logic problems is that of lateral flow in the
soil's upper horizons.  The nature and quantity involved in this quick-return flow
are unkown and have to be inferred from the shape of the observed hydrograph.  An
attempt has been made to mathematically simulate the flow phenomenon using rainfall
as input and a system of interconnected, nonlinear reservoirs as the operator.

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                                     SECTION IV
                       WATER CYCLE - GROUNDWATER  (Group 02F)


 68-69:02F-001
 DISPERSION AT THE  INTERFACE OF MISCIBLE LIQUIDS IN A SOIL,
 Li, W. H., and Yeh, G. T.
 Syracuse University, Syracuse, N.Y.
 Water Resources Research, Vol. 4, No. 2, p 369-377, April 1968.  7 fig, 10 ref.

 Descriptors:  *Ground water, Porous media, *Saline water, *Dispersion.
 Identifiers:  *Fick's law, *Miscible liquids.

 When two miscible  liquids flow through a porous medium  (e.g., fresh water and salt
 water in an aquifer), the dispersion at the interface is described by Pick's law
 with a velocity-dependent coefficient.  In the first part of this paper, the horiz-
 ontal flow of two  liquids is used to demonstrate that the influence of gravity and
 the effects of the differences in density and viscosity are usually negligible.  Then
 solutions are presented for the dispersion at the interface of liquids in two-dimen-
 sional flow.
68-69:02F-002
CONSTRUCTION OF PIEZOMETERS, AND METHOD OF INSTALLATION FOR GROUND WATER OBSERVATIONS
IN AQUIFERS,
Obbink, J. Groot.
Commonwealth Scientific and Industrial Research Organization, Merbein, Victoria, Div
of Horticultural Research.
Journal of Hydrology, Vol. 7, No. 4, p 434-443, April 1969.  9 fig.

Descriptors:  *Piezometers, *0bservation wells, *0peration and maintenance, Instru-
mentation, Well casings, Well filter, Wellpoints, Wells, Well screens, Drilling,
Aquifers.
Identifiers:  Well drilling, Well jetting  (Drilling).

Over the period of 1952-1963, groundwater studies were carried out by C.S.I.R.O. in
various irrigation districts in South Australia, Victoria, and New South Wales.  Pie-
zometers were installed to observe the behavior of ground water in aquifers underly-
ing these areas.  A description is given of 2 types of screens which have been used
and the methods of installation by jetting or rotary drilling.  A detailed descrip-
tion of jetting equipment is given and the use of both types of screens discussed.
The material encountered was recent riverine clays and sand, and one particular pie-
zometer site is illustrated.  Testing and maintenance of the installed piezometers
are described.
68-69:02F-003
ENTRY VELOCITY CONTROL LIMITS DRAIN SEDIMENTATION,
Willardson, L. S., Fouss, J. L., Reeve, R. C., and Fansey, N. R.
Agricultural Research Service, Brawley, California.
Journal of Irrigation and Drainage Division, ASCE, Vol. 94, No. IR4, December 1968.
4 fig, 1 tab, 10 ref.

Descriptors:  *Drainage, *Drains, *Sedimentation, Ground water, Filters, Tiles.

Control of the velocity of water entering a subsurface drain will effectively prevent
sedimentation.  An anti-sedimentation concept based on the Stokes Law settling veloc-
ity of particles is described in detail.  The essential element for implementation of
the concept is an entrance flow path or channel to the drain in which both the magni-
tude and direction of the inflow velocity of water are controlled.  Laboratory tests
are reported for different sized particles, shapes of opening, and cross-sectional
areas of flow.  Tentative design criteria are suggested.  The prevention of sediment
entry into drains by this method is not by a filtering process.
                                      19

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 68-69:02F-004
 REDUCED  SODIUM  EXCHANGE  CAPCITY  IN UNSATURATED FLOW,
 Mokady,  R.  S.,  and Bresler, E.
 National and University  Institute of Agriculture, Rehovoth, Israel.
 Soil  Science Society of  America  Proceedings, Vol. 32, No. 4, p 463-467, July-August,
 1968.  7 fig, 1  tab, 11  ref.

 Descriptors:  *Ion exchange, Diffusion, Anisotropy, Hydrodynamics.
 Identifiers:  Flow through porous media.

 Flowing water with a reduced degree of saturation seems to reduce the apparent or
 effective cation-exchange capacity.  The experiment was performed by running water
 through  a layered soil,  thus obtaining unsaturated flow conditions.  It is suggested
 that  the flow direction  induces  anisotropy with respect to molecular diffusion.  The
 hydrodynamic dispersion  in the flow direction is almost unaffected.  At the same
 time, there must be some locations off the main water stream with which there is
 negligible  mixing or molecular exchange by diffusion.  One may associate to these
 isolated locations a prevailing  direction normal to the mainstream.  In this case,
 it can be said  that the  unsaturated flow induces anisotropy on ion transfer by mixing
 or molecular diffusion.
68-69 :02F-005
SOLUTION OF UNUSUAL SUBSURFACE DRAINAGE PROBLEM,
Brand,  E. W.
Nottingham University, Nottingham, England.
Journal of the Irrigation and Drainage Division, ASCE ,  Vol. 94, No. IR2 ,  p 199-221,
June 1963.  11 fig, 2 tab, 2 ref.

Descriptors:  * Drainage, *Groundwater , * Irrigation, Drawdown ,  Pumping, Wells,
Corrosion, Highways.
     ifiers:  Antwerp, Belgium.
    ti
Details are given of all the stages in the design of the sophisticated subsurface
drainage svstem in the city of Antwerp, including the execution of extensive field
pumping tests, the analysis of the alternative solutions to the problem, and the
study of the hydraulics of the horizontal intake pipes adopted to effect the ground-
water lowering.  The possible effect of precipitation of ferric oxide from the
grcundwater is considered.  This most important factor complicated the design, and
necessitated complete submergence of the intake system.
68-69:02F-006
SOME PROBLEMS CONNECTED WITH OPERATION OF DRAINAGE SYSTEMS,
Daishev, T. I., and Sannikcv, G. P.
International Commission on Irrigation & Drainage Bulletin, p 15-21, July 1968 -
January 1969,  2 tab.

Descriptors:  *Drainage, Drainage engineering,* Drainage systems, *Tile drainage. Sub-
surface drainage, *Freezing, *Weed control, *Herbicides, Muck soils, *Silting, Peat,
Reclamation.

This paper considers some factors causing failure of individual parts of a drainage
system. Particular attention is paid to the following problems: the influence of kyr-
ogen phenomena or. the safety and operation of drainage; protection of channels con-
structed in soils most subjected to the frost influence; chemical measures for remov-
ing undesirable plants from drain channels. The main factors leading to silting of a
closed drainage line are as follows: measures for drain protection do not correspond
to the nature of silting and physico-mechanical properties of soil and the quality of
construction works is not sufficiently high. Frozen mineral soils are permeable dep-
ending on moist content during freezing. As to the permeability of frozen peats, it
is not yet sufficiently investigated.  The main factors defining depth of peat freez-
ing are:  daily average negative temperatures in winter; snow cover density and depth;
moisture content of soil.  To prevent slope deformation caused by freezing and thaw-
ing, it is necessary to cover the slope surface with a 15-20 cm layer of soils, which
are not subjected to frost influence.  Use of chemical methods of weed control in-
stead of mechanical, thermal or biological, reduces expenses by 1.5 - 2.0 times and
increases labor productivity by 5-10 times.
                                       20

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68-69:02F-007
THE MOVEMENT OF RADIOACTIVE SODIUM AND RUTHENIUM THROUGH A SIMULATED AQUIFER,
Champlin, J. B. F., and Eichholz, G. G.
Georgia Institute of Technology, Atlanta.
Water Resources Research, Vol. 4, No. 1, p 147-158, February 1968.  8 fig, 20 ref.

Descriptors:  *Groundwater, *Pollution, *Soils, Radioactivity, Aquifer, Sodium,
Potassium, Calcium.

The interaction of water solutions with the particulate matter composing a natural
aquifer is of steadily increasing interest with the new emphasis on pollution of our
natural resources.  As a means of studying the contribution made by water to the
transport of ionic materials through soils, radioactive solutions were injected into
a model aquifer containing 725 kg of sand with dimensions of 1x2x0.25 meters.  As the
radioactivity passed through the sand, its progress was followed by a collimated Gei-
ger Muller tube situated on the exterior of the bed.  The appearance of the radio-
activity in the effluent, which marked the arrival of the sodium front, was found to
be correlated with an increase in suspended particulate matter, potassium and calcium
concentrations, and overall conductivity.  Of particular significance was that por-
tion of the radioactivity shown to be related directly to the filterable mass of par-
ticles in the effluent, despite the high solubility of the ion used.  The results
with the sodium were compared with those of similar tests on the movement of trival-
ent ruthenium, which is not soluble at the pH of the solutions used.  Both the sodium
and ruthenium studies indicated that a significant amount of radioactivity was trans-
ported through the test bed on particulate matter which was large enough to be
trapped on 0.45 micron membrane filters.
68-69:02F-008
WATER USE BY COTTON FROM LOW AND MODERATELY SALINE STATIC WATER TABLES,
Namken, L. N., Wiegand, C. L., and Brown, R. G.
Agricultural Research Service, Weslaco, Texas.
Agronomy Journal, Vol. 61, No. 2, p 305-310, March-April, 1969.  4 fig, 4 tab, 11 ref.

Descriptors:  *Lysimeters, *Salinity, *Ground water, Saline water, Water table. Per-
vious soils, Cotton, Irrigation.
Identifiers:  *Capillary zone salinity.

A 4-year lysimeter study was conducted to determine the contribution of low to moder-
ately saline, shallow static water tables to the total water use and yield of cotton
grown on deep, permeable soils.  Water tables controlled at 91-, 183-, and 274-cm
depths contributed 51.4, 26.4, and 17.3% of the total water use under the high mois-
ture treatment and 60.6, 48.9, and 39.2% under the low moisture treatment.  Total
water use consisted of soil profile depletion, rainfall, irrigations, and additions
of water to maintain the water tables.  Water uptake from the 274-cm water table was
strongly related to the salinity level (electrical conductivity of saturated soil
extract, ECp) of the capillary  (183- to 274- cm) zone.  Lint cotton yields were rel-
ated to the total amount of water obtained from the table as well as to the salinity
level of the capillary zone.  Moderate salinity (ECg of 10 to 14 mmhos/cm) of the
capillary zone reduced monthly and seasonal water use from the water tables as com-
pared with the low salinity (ECQ of 2 to 3 mmhos/cm) conditions.  The high moisture
treatment delayed significant use of water from 183- and 274- cm water tables until
late in the season, when irrigations were discontinued and the upper soil profile
dried.
68-69:02F-009
PERFORMANCE OF TILE DRAINS UNDER IRRIGATION IN SOUTHERN ALBERTA,
Rapp, E., and Laliberte, G. E.
Lethbridge, Alberta, Canada, Dept of Agriculture.
Canadian Agricultural Engineering, Vol. 10, No. 2, p 64-69, 1968.  2 tab, 6 fig,
11 ref.

Descriptors:  Irrigation, *Saline soils, *Saturated soils, *Drainage systems, *Tile
drainage. Arid lands, Semiarid climates, Groundwater, Subsurface drainage, Drainage
effects. Loam, Sands, Tiles, Irrigation engineering, Water table.
Identifiers:  *Canada, Alberta.

In an arid environment where irrigation is necessary to agricultural production, tile
drains are often used to prevent water logging and salinity or to reclaim soil that


                                      21

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 was originally saline.   The proportion of water applied that must be  handled  by  the
 drainage system will vary according to soil,  water and climatic conditions.   The
 study was conducted in  southern Alberta to provide guidelines for designing irriga-
 tion drainage systems for that area.   Five tile drain systems were tested  in  areas of
 sandy loam and loams over sand for a  12-year  period.   Two interceptor tile drain sys-
 tems proved highly effective in removing excess water and salts.   The performance of
 three relief tile drains was highly variable.  Since  salinity of  the  effluent from
 relief drains showed no decrease with time, they were judged doubtful for  reclamation
 purposes although they  did effectively remove excess  water.   If relief drains are to
 be used, the authors suggest that spacing should be no more  than  700  to 800 feet to
 achieve greater effectiveness.
 68-69:02F-010
 PLASTIC  ORIFICE INSERTS  FOR SUBSURFACE IRRIGATION,
 Whitney,  L.  F., and  Lo,  K.  M.
 Massachusetts  University, Amherst,  Dept of Agricultural  Engineering.
 American Society of  Agricultural  Engineers,  Transactions, Vol.  12, No.  5, p  602-604,
 607,  September-October,  1969.   3  fig,  6 tab,  4  ref.

 Descriptors:   *Subsurface irrigation,  *Irrigation design, *Plastics,  *0rifices,
 *Pipes,  Flow rates.  Equipment,  Irrigation  systems, Nozzles, Orifice flow, Pipe flow,
 Porous media,  Application methods.  Costs,  Design, On-site tests, Tubes, Water distri-
 bution  (Applied).

 Economies  in water use,  plus advantages of liquid fertilizer  and herbicide injection,
 have  made  subsurface irrigation the object of much study.  Research has shown that
 the major  problem of using  plastic  pipe for  underground  irrigation networks  lies in
 developing a discharge orifice  that resists  clogging  from internal water impurities
 and external soil particles.  Three orifice  designs were investigated: porous media,
 in-wall  orifices  protected  by labyrinths,  and plastic  insert  orifices.  Results of
 the study  were disappointing for porous media and in-wall orifice designs, the latter
 being completely  unreliable.  A plastic insert  orifice was designed which featured
 uniform water  distribution,  easy  installation,  and low manufacturing  cost.
68-69:02F-011
AN APPLICATION OF SURFACE GEOPHYSICAL TECHNIQUES TO THE STUDY OF WATERSHED HYDROLOGY,
Shields, Ronald R., and Sopper, William E.
Geological Survey, Helena, Montana.
Water Resources Bulletin, Vol. 5, No. 3, p  37-49, September 1969.  6 fig, 2 tab,
16 ref.

Descriptors:  *Hydrogeology, *Surveys, *Geophysics, *Seismic studies, *Electrical
studies, Aquifers, Water table, Water management  (Applied), Subsurface mapping, Small
watersheds, Water storage, Springs, Streams.
Identifiers:  Groundwater prospecting  (Geophysical).

The applicability of geophysical methods to experimental watershed research is demon-
strated by a study of a 106-acre forested watershed in central Pennsylvania.  Data
from a shallow seismic refraction study and an electrical resistivity study of the
watershed were used to determine the depth of soils, their volumes, depth to bedrock,
configuration of the bedrock surface and delineation of the bedrock surface and of
the water table.  With this information on the subsurface conditions, the hydrologic
properties of the watershed were described in greater detail.  This information is of
value in explaining the watershed's response to various watershed treatment practices
that eventually will be used.
68-69:02F-012
DETERMINING SPECIFIC YIELD OF THE OGALLALA AQUIFER BY THE NEUTRON METHOD,
Jones,  Ordie R., and Schneider, Arland D.
Agricultural Research Service, Bushland, Texas.
Water Resources Research, Vol. 5, No. 6, p 1267-1272, December 1969.  5 fig, 2 tab,
10 ref.

Descriptors:  *Specific yield, *Aquifers, *Alluvium, *Nuclear moisture meters, Texas,
Instrumentation, Surveys, Radioactivity, Water levels, Water level fluctuations, Per-
meability .


                                       22

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Identifiers:  Ogallala Formation, Neutron moisture,meters, Pumping tests, Aquifer
testing.

The specific yield of the Ogallala formation, a water table aquifer, was determined
with a neutron moisture meter.  An access tube penetrated a 12-foot section of the
aquifer.  This section was saturated by recharging water to the aquifer and then
dewatered by pumping for 11 days.  The specific yield of the aquifer was calculated
from neutron moisture measurements made at saturation after most gravity drainage had
occurred.  The average specific yield for 25 measurements made at 1/2-foot intervals
was 0.22.  This value compares favorably with the specific yields determined by trac-
tor techniques and laboratory analysis of cores.  However, the specific yield deter-
mined by the neutron method was 50% greater than the specific yield determined by
pumping tests.
68-69:02F-013
METHOD FOR COMPUTING GROUNDWATER LEVEL FLUCTUATIONS,
Vol'ftsun, I. V.
Translated from State Hydrolog^c Institute (Trudy GGI),  No. 165, p 128-147, 1969.
Soviet Hydrology: Selected Papers, Issue No.  2, p 115-130, 1969.  7 fig, 4 tab, 2 ref,
3 append.

Descriptors:  *Water level fluctuations, *Groundwater, *Water balance, *Hydrologic
budget. Infiltration, Precipitation (Atmospheric), Recharge, Evapotranspiration,
Discharge  (Water), Groundwater movement, Water table, Surface-groundwater relation-
ships .
Identifiers:  Groundwater-level fluctuations.

A water balance method can be used to calculate groundwater-level fluctuations during
the growing season.  For coarse-texture soils and a groundwater.depth of about 1.5 m,
when the seepage time of precipitation through the aeration zone is 1 day or less,
when there is no backwater from rivers or lakes, and no water exchange between aqui-
fers , the method of computation described can be used to precalculate the groundwater
level one day in advance.  It can also be used to predict fluctuations of flow over a
long period preceding a given data, from precipitation,  air moisture deficit, and
wind speed data.  It is possible to determine the effect of human activity, such as
for example, the planting of forests,  various agricultural practices, etc., on
groundwater level regime and surface runoff in the catchment.
68-69:02F-014
THE USE OF THE GEOELECTRIC METHOD FOR INVESTIGATING GEOLOGIC AND HYDROLOGIC CONDI-
TIONS IN SANTA CLARA COUNTY, CALIFORNIA.
Page, Leo M.
Santa Clara Valley Water Conservation District, California.
Journal of Hydrology, Vol. 7, No. 2, p 167-177, January 1969.  8 fig, 1 tab, 5 ref.

Descriptors:  *Electrical studies, *Resistivity, *Surveys, *Groundwater, Geophysics,
Aquifers, Water table, Water levels, Water level fluctuations. Porosity, Permeability,
Transmissivity, Water yield, Discharge  (Water).
Identifiers:  *Santa Clara County (Calif.).

The basic procedures used in electric resistivity exploration of geologic and hydro-
logic conditions in Santa Clara County, California are described.  Typical examples
of resistivity information checked against drilling and well testing are included.
The advantages of the resistivity method are low cost, ease of operation, speed,
accuracy, and ease of training operations.  The initial cost of the equipment used
was about 51,000 and the maintenance cost was about $100 per year.  Since 1964, over
800 electric soundings to depth of 200-500 ft and over 10,000 shallow profiles were
made.  The Wenner and Schlumberger electrode configurations are used.  The usual pro-
cedure is to run a grid of profiles to learn the general geological properties of an
area and then to make several probes to learn the vertical extent of the major geo-
hydrologic zones.  Recent water level conditions in the county are mapped.
                                       23

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 68-69:02F-015
 TILE CLOGGING BY IRON AND MANGANESE IN IMPERIAL VALLEY,  CALIFORNIA.
 Grass,  Luther B.
 Agricultural Research Service,  Brawley,  California.
 Journal of Soil Water Conservation, Vol. 24,  No. 4,  p 135-138,  July-August 1969.
 7 fig,  2 tab, 19 ref.

 Descriptors:  *Drain tiles,  *Tile drains,  *Iron oxides,  Manganese  compounds.  Drain-
 age, Drainage engineering.  Drainage systems,  Tiles,  Tile drainage, Drains,  Deposi-
 tion, Chemical precipitation,  Soil types,  Operation  and  maintenance,  Irrigation opera-
 tion and maintenance, Bibliographies,  Iron bacteria.
 Identifiers:  *Clogging,  Imperial Valley (Calif.),  Imperial  Irrigation  District
 (Calif.}.

 Tile drains are used extensively in the  Imperial Valley  of California to  control
 water tables and prevent  salt  accumulation in soils.   By 1955,  water  tables had dev-
 eloped  over some tile lines, reducing  crop growth either by  restricting root  growth
 or by increasing salinity.   When opened  for inspection,  the  lines  were  found  clogged
 by black and red deposits composed of  manganese and  iron oxides.   Theories  proposed
 to explain the deposits are:  (1)  the problem predominates near  faults,  (2)  the prob-
 lem is  peculiar to  certain soil  textures,  and (3)  the type of tile used contributes
 to the  problem.   A  survey was made of  tile lines in  the  Imperial Valley.   The sever-
 ity of  clogging varied widely  and the  deposits  were  observed in various physical
 forms.   The survey  indicated that formation of  red or black  deposits  was  not  related
 to location, soil type, kind of  tile material,  or length of  time the  drains had been
 in service.   Tile systems clogged with iron and manganese deposits can  be reclaimed
 effectively by treatment  with  sulfur dioxide  gas and  water.
 68-69:02F-016
 DRAIN  INSTALLATION FOR NITRATE REDUCTION,
 Willardson, L.  S., Meek,  B. D.,  Grass,  L.  B., Dickey, G. L., and Bailey, J. W.
 Agricultural Research Service, Brawley, California.
 Groundwater, Vol. 8, No.  4, p 11-13, July-August 1970.  2  fig,  2 tab, 2 ref.

 Descriptors:  *Denitrification,  *Biodegradation, *Nitrates, *Groundwater,  *Drainage
 systems,  Subsurface drainage, Drawdown, Water level  fluctuations,  Saturated flow,
 Unsaturated flow, Aeration.
 Identifiers:  Groundwater denitrification.

 A  field experiment was installed near Firebaugh in the San Joaquin Valley  of Calif-
 ornia  to  test submerged drains as a means  of denitrification of groundwater.  Labora-
 tory and  field  experiments show  that denitrification occurs in  saturated soil where
 there  is  ample  organic carbon available for bacterial metabolism.  Denitrification
 and dilution of high nitrate groundwater were accomplished in the  field study.
68-69:02F-017
GROUNDWATER MOVEMENT TOWARD ARTIFICIAL CUTS,
Kashef, Abdel-Aziz I.
North Carolina State University, Raleigh.
Water Resources Research, Vol. 5, No. 5, p 1032-1040, October 1969.  3 fig, 2 tab,
11 ref.

Descriptors:  *Groundwater movement, *Saturated flow, *Steady flow, *Excavation,
Drainage, Water table, Water levels, Aquifers, Hydraulic conductivity, Aquicludes,
Seepage, Inflow.
Identifiers:  Drainage to excavations.

Artificial cuts, such as open channels and highway cuts, produce an imbalance in the
original groundwater system.  The developed drawdowns due to these cuts under the
condition of saturated steady flow are studied theoretically by analyzing the seep-
age through trapezoidal sections of earth entailing the complexity of the free sur-
face.  The procedure is then extended to actual cases of extensive aquifers where
such cuts exist.  The proposed method is compared with some of the available rigorous
mathematical solutions, such as those given by Falkovich, Mikhailov, Meletchenko,
Pavlovsky, and Polubarinova-Kochina.  The proposed method is simpler in its applica-
tion and also gives a complete solution for the free surface, the discharge face, the
rate of flow, and the hydropotential distribution within the affected region, whereas
the rigorous methods are planned essentially for the solution of the free surface
only.

                                     24

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68-69:02F-018
PERMEABILITY OF ORTHOTROPIC POROUS MEDIUMS,
Szabo, Barna A.
State University of New York, Buffalo.
Water Resources Research, Vol. 4, No. 4, p 801-808, August 1968.  4 fig, 1 tab,
13 ref.

Descriptors:  *Porous media, *Mohr circle, *Permeability,  Darcy's Law, Groundwater,
Hydraulics, Mathematical studies.
Identifiers:  Transformation law, Orthotropic,  Porous mediums.

A mathematical definition of permeability is developed from the assumption that orth-
otropic porous mediums obey Darcy's Law in the three directions normal to the struc-
tural planes of symmetry of the medium.  This assumption leads to the conclusion that
permeability obeys the transformation law definitive of second-order tensors; and
that consequently a permeability quadric  (the Mohr circle representation of transfor-
mation of permeability components and permeability invariants) can be defined.  It
was concluded that permeability, because of its transformation properties, is analo-
gous to these conceptually unrelated physical objects.  This analogy permitted the
application of the Mohr circls to represent the transformation of permeability com-
ponents in any principal plane.
68-69:02F-019
NUMERIC STUDIES OF A COMPOSITE SOIL MOISTURE GROUNDWATER SYSTEM,
Hornberger, G. M., Remson, Irwin, and Fungaroli, A. A.
Drexel Institute of Technology, Philadelphia, Pa.
Water Resources Research, Vol. 5, No. 4, p 797-802, August 1969.  5 fig, 1 tab, 7 ref.

Descriptors:  *Groundwater movement, *Soil water movement, *Mathematical models,
Model studies, Infiltration, Percolation, Water table, Darcy's' Law, Dupuit-Forch-
heimer theory.
Identifiers:  Soil water-groundwater relations.

A model of transient moisture movement in a composite soil moisture-groundwater sys-
tem is described.  The model was used to study two-dimensional flow in response to a
falling water table. The solution provided information about the interaction of the
saturated and unsaturated portions of the subsurface system.  The results of the com-
posite model are compared with those obtained from three one-dimensional groundwater
models.  That soil moisture and nonlinearity do not have a significant effect on the
position of the water table in the system studied is inferred.
68-69:02F-020
SIMILARITY APPROXIMATION FOR THE RADIAL SUBSURFACE FLOW PROBLEM,
Drake, R. L., Molz, F. J.,  Remson, Irwin, and Fungaroli, A. A.
Drexel Institute of Technology, Philadelphia, Pa.
Water Resources Research,  Vol. 5, No. 3, p 673-684, June 1969.  3 fig, 1 tab, 12 ref.

Descriptors:  *Mathematical models, *Mathematical studies, *Approximation method,
*Groundwater movement, Flow, Porous media, Saturated flow, Unsaturated flow, Synthe-
tic hydrology, Simulation analysis, Computer programs, Digital computers.
Identifiers:  *Similarity approximation, Radial groundwater flow.

A useful mathematical technique in the study of radial flow of underground water is
the application of similarity transformations, such as Boltzmann's transformation.
The transformations lead to approximations that are shown to be valid if certain
physical parameters satisfy given limiting conditions.  A nonlinear partial differ-
ential equation is formulated describing the radial flow of soil moisture.  A simil-
arity approximation is used to transform the partial differential equation into a
nonlinear ordinary differential equation.  Criteria by which to judge the applica-
bility of the similarity approximation are derived.  Several monotonicity properties
of the transformed moisture as a function of the similarity variable are derived.
The properties are used to develop numeric procedure for the solution of the trans-
formed equation.  The procedure is used to study the radial flow of soil moisture to
a cylindric sink for diffusivities which vary linearly, quadratically, and exponen-
tially with soil moisture.   The solutions show that the moisture front steepens with
increasing nonlinearity.
                                      25

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 68-69:02F-C21
 UNSTEADY SEEPAGE FLOW BETWEEN FULLY-PENETRATING TRENCHES,
 Karadi,  Gabor,  Krizek,  Raymond J...  and Elnagger,  Hameed
 Wisconsin University,  Milwaukee,  Dept of Mechanics.
 Journal  of Hydrology,  Vol.  6, No. 4,  p 417-430, August 1968.   9  fig,  3  ref.

 Descriptors:   *Ur.steady flow, *Groundwater movement,  *Drainage effects,  *Ditches,
 Dupuit-Forchheimer theory,  Digital  computers.
 Identifiers:   Matrix computation  methods.

 Unsteady seepage flow  between 2 fully penetrating trenches  is  analyzed  for homogen-
 eous  isotropic  porous  media characteristics.   The solution  may be  extended to  a
 cross-anisotropic porous medium.  The method  uses matrix mathematics  to  solve  a  non-
 linearized equation derived from  Dupuit-Forchheimer  approximations and  the replace-
 ment  of  partial differential equations with a  system of ordinary differential  diff-
 erence equations.  The  method may easily be adopted  to computers and  handles compli-
 cated boundary  and initial  conditions as well  as  allowing step by  step  treatment of
 the non-linearity of the differential equation.  The results calculated  are in better
 agreement with  experimental results than are  results obtained  by the  use of linear-
 ized  field equations.
 68-69:02F-022
 PERMEABILITY CALCULATED  FROM DESATURATION  DATA,
 Laliberte,  Garland  E., Brooks, Royal  H., and  Corey,  Arthur  T.
 Canada Dept of Agriculture,  Lethbridge, Alberta.
 ASCE  Proceedings, Journal  of the  Irrigation and Drainage Div., Vol.  94, No.  IR1,
 Paper No.  5843,  p 57-71, March 1968.  '3 fig,  3 tab,  23  ref,  2 append.

 Descriptors:  *Permeability,  *Porous  media, *Soils,  *Pore pressure,  Drainage, Model
 studies, Equations,  Soil compaction,  Saturation,  Regression  analysis.
 Identifiers:  Capillary  pressure-permeability relationships, Porosity-permeability
 relationships, Kozeny equations.

 An equation is presented for calculating saturated permeability  from capillary
 pressure-desaturation data.   The  use.  of this  equation along  with  the relative per-
 meability  equations  of Brooks and Corey is prooosed  for calculating  the permeability
 of both saturated and partially saturated  media.  The analysis leading to the devel-
 opment of  the equation is  based on  theory  developed  in  the  petroleum industry.  The
 equation utilizes parameters  introduced by Brooks and Corey  for describing the hyd-
 raulic behavior  of partially saturated porous media  on  the  drainage  cycle.   In lab-
 oratory measurements, the  permeability of  tnree disturbed soils each packed  at 5
 different  values of  porosity was determined at various  capillary  pressures.  Predic-
 ted relationships were calculated using capillary pressure-desaturation data in the
 new equation and in  the relative permeability equations of  Brooks and Corey.  Calcul-
 ated  and experimental values  of permeability  agreed  within  27% over  the range of
 capillary  pressures  studied.
68-69:02F-023
LABORATORY EVALUATION OF SELECTED RADIOISOTOPES AS GROUND-WATER TRACERS,
Jennings, A. Ray, and Schroeder, Melvin C.
Texas AiM University, College Station.
Water Resources Research, Vol. 4, No. 4, p 829-838, August 1968.  2 fig, 3 tab,
16 ref.

Descriptors:  *Tracers, *Radioisotopes, *Grouna-water  ^ovement. Velocity  distribu-
tion pattern, *Ion exchange, Adsorption.
Identifiers:  *Groundwater tracers, Radioactivity.

Tracer appearance results from movement along the most direct flow path, and thus
arrival of the maximum concentration is the best index for determining average water
velocity.  Antimony 121, cerium 141. chromium 51, indium 114, ruthenium 103, and
strontium 85 in cheiate form were tested, as the unchelated ions are subject to
greater decay by adsorption and ion exchange.  Distribution-coefficient measurements
were made under static conditions for crushed illitic shale and limestone.  These
measurements can be used to predict the eiution history of a tracer from an exchange
column.  Comparisons of the predictions, the tracer eiution histories, and eiution
histories for chloride pulses indicate that cbeiated chromium 51 is an adequate
grcundwater tracer.   Average velocity 31 .jroaiidv/a!:or is equal to the sum of the


                                      26

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tracer velocity plus the product of the tracer velocity, the distribution coeffi-
cient, and the bulk density of the aquifer divided by its effective porosity.  The
distribution coefficient for an ideal tracer is zero; the average velocity of this
tracer is equal to the average groundwater velocity.
68-69:02F-024
TWO-DIMENSIONAL SEEPAGE OF BONDED WATER TO FULL DITCH DRAINS,
Warrick, A. W., and Kirkham, Don.
Iowa State University, Ames, Dept of Agronomy.
Water Resources Research, Vol. 5, No. 3, p 685-693, June 1969.  4 fig, 8 ref.

Descriptors:   *Drainage systems, *Ditches, *Seepage, *Mathematical models, Synthetic
hydrology, Drainage engineering, Dewatering, Hydraulic conductivity, Anisotropy,
Soils, Soil water movement, Groundwater movement.
identifiers:   Nomogram.

Seepage of ponded water to full, equally spaced ditch drains is analyzed mathematic-
ally, considering 4 distinct cases.  In the first case, an impermeable soil barrier
is present at  a finite depth, and the ditches are a finite distance apart; in the
second case, no impermeable soil barrier is present, and the ditches are a finite
distance apart; in the third case, an impermeable barrier is present, but the ditches
are in effect  an infinite distance apart; and in the fourth case, no impermeable
barrier is present, and the ditches are in effect an infinite distance apart.  The
ditches may penetrate part or all of the way to an impermeable barrier.  Schwartz-
Christoffel transformations are used to solve the first case.  Solutions for the
other 3 cases  are found by taking limiting values of the first case.  Flow nets ill-
ustrate the results.  In one calculated example, the flow rate without an impermeable
barrier is 10% greater than when an impermeable barrier exists at a depth of 0.2
times the ditch sei.iispacing. The flow nets illustrate the rapid decrease in surface
water intake at increasing distances from the ditch.  A nomogram gives seepage rates
when no impermeable barrier is present and infinitely wide spacing is used.  An ill-
ustration shows that the nomograph is useful to estimate seepage rates for flow media
of finite depth and width.
68-69:02F-025
ROOTZONE SALT PROFILES AND ALFALFA GROWTH AS INFLUENCED BY IRRIGATION WATER SALINITY
AND LEACHING FRACTION,
Bower, C. A., Ogata, G.,  and Tucker, J. M.
Agricultural Research Service, Riverside, Calif.
Agronomy Journal, Vol. 61, No. 5, p 783-785, September-October 1969.  1 tab, 3 fig,
2 ref.

Descriptors:  *Arid lands, *Irrigation water, *Drainage water, *Saline water, *Plant
growth, Saline soils, Lysimeters, Alfalfa, California, Root zone, Soil-water-plant
relationships.

Alfalfa was grown in 24 lysimeters at Riverside, California, with 12 irrigation water
salinity and leaching fraction treatments.  Plant yield was related to the salinity
that developed in the root zone.  The first increments of leaching were most effect-
ive in preventing salt accumulation in the soil.  At high leaching fractions, much
of the water applied beyond that required for evapotranspiration was of little effect
in lowering soil salinity.
68-69:02F-026
THE INFILTRATION COMPONENT OF A PASTORAL EXPERIMENTAL CATCHMENT, PARTS 1 AND 2,
Dunin, F. X.
Soil Conservation Authority, Kew, Australia.
Journal of Hydrology, Vol. 7, No. 2, p 121-146, January 1969.  8 fig, 6 tab, 13 ref.

Descriptors:  *Surface-groundwater relationships. *Hydrograph analysis, Rainfall-
runoff relationships, Rainfall disposition, Infiltration, Recharge, Streamflow, Run-
off, Bank storage, Base flow, Water storage, Antecedent precipitation, Demonstration
watersheds, Model studies, Water management  (Applied).
Identifiers:  *Australia, Parwan Experimental Area, Antecedent soil moisture.
                                      27

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 A method of hydrographic analysis is proposed for  the determination of  the  average
 infiltration rate during specified intervals  of  a  surface  runoff  event.   This method
 uses the continuity equation to follow the  disposition of  the  rainfall  during the
 selected hydrograph intervals,  using a measure of  the surface  detention relations
 for the catchment under study.   The variation of the  infiltration rate  during the
 runoff event under analysis was expressed as  an  inverse exponential relationship
 between infiltration rate and accumulated soil moisture.   Description of infiltration
 characteristics  in this form facilitates the  assessment of hydrologic effects of
 changed land-use.   Infiltration characteristics  of a  series of runoff events were com-
 pared as a  measure of the efficacy of hydrographic analysis and also to  provide a
 mathematical description of the infiltration  component of  the  experimental  catchment.
 This involved the estimation of soil moisture antecedent to runoff production by an
 indirect method  based on the simulation of  runoff  production.
                                               The comparison  demonstrated  that in-
 filtration  characteristics were consistent  with  either of  two  relationships derived
 from hydrographic analysis.  The variation  of the  infiltration performance  between
 these two sets of infiltration  characteristics was shown to be seasonal  and was
 attributed  to swelling of the colloid fraction of  the soil.
 68-69:02F-027
 HYDRODYNAMIC DISPERSION  IN A  SATURATED HOMOGENEOUS POROUS MEDIUM AT LOW PECLET NUM-
 BERS AND NON-HOMOGENEOUS SOLUTION,
 Bachmat, Yehuda.
 Guelph University, Ontario, Canada.
 Water Resources Research, Vol.  5, No. 1, p 139-143, February  1969.  7 ref.

 Descriptors:   *Dispersion, *Diffusion, *Porous media, Flow, Groundwater movement,
 Density, Circulation, Fluid mechanics, Mass transfer, Mixing.
 Identifiers:   Binary solutions. Density gradient.

 The coefficient of mechanical dispersion of a solute in a homogeneous porous medium
 saturated by a binary diluted solution is derived, taking into account nonuniform
 density and viscosity fields.   It is shown that in the neighborhood of a vanishing
 macroscopic velocity, a  nonuniform density field induces a macroscopic dispersion
 resulting from the variation of microscopic density gradients and from horizontal
 variations of  the macroscopic density.  Both together yield the macroscopic effect
 of density instability on solute redistribution phenomena in  porous materials.
68-69:02F-028
THE USE OF GRAVITY SHAFTS FOR GROUNDWATER RECHARGE - PHASE I,
d'Errico, T. R., and Skodje, M. T.
North Dakota Water Resources Research Inst., Fargo.
Research Project Technical Completion Report, Water Resources Research Inst. WI-222-
002-70, January 1970.  22 p, 2 tab, 8 fig.

Descriptors:  Laboratory tests. Permeability, Turbidity, *Sedimentation, *Shafts
(Excavations), Groundwater recharge, North Dakota.
Identifiers:  Sheyenne River  North Dakota), *Gravity recharge. Sand-filled shafts,
Clogging patterns, Air-binding.

The hydraulic characteristics of shafts consisting of uniformly graded sand were
studied in the laboratory to predict their applicability for the recharge of glac-
ially deposited aquifers overlain with impervious soils.  Water containing various
levels of turbidity was applied to shafts consisting of three different sizes of
sand.  Piezometers were used to measure the head-loss gradients.  At the completion
of each test, the amount of sediment trapped in the different levels of the shaft was
determined.  Permeabilities of the three sand sizes using clear tap water were ob-
served to be 14,400, 4,500, and 3,400 GPD per square foot.  No  'airbinding' of the
shafts was noted, and the clogging of the shafts was limited to the upper three
inches of the shaft.  Below this layer the permeability remained constant.  Field
tests should be conducted to determine whether periodic restoration of the upper
level of the shaft is more economical and practical than shaft abandonment and re-
placement.  Two different shaft designs are proposed for use with these two methods
of operation.  The permeability of the shaft is decreased more rapidly when higher
turbidities are applied.  Sedimentation of the Sheyenne River water as a method of
reducing the sediment loading does not appear practical except during high river
stages when turbidities exceed 100 mg per liter.


                                     28

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68-69:02F-029
GROUNDWATER STUDIES IN THE SABI VALLEY, RHODESIA, USING NATURAL TRITIUM MEASUREMENTS,
Wurzel, P., and Ward, P. R. B.
Agricultural Research Council of Central Africa.
Journal of Hydrology, Vol. 8, No. 1, p 48-58, May 1969.  2 fig, 1 tab, 10 ref.

Descriptors:  *Groundwater movement, *Tracers, *Tritium, Base flow, Laboratory tests,
Electrolysis, Radio-chemical analysis, Surface-groundwater relationships.
Identifiers:  *Sabi Valley (Rhodesia).

Environmental tritium was used as a groundwater tracer in the Sabi Valley Alluvial
plain in Rhodesia, and flow data was obtained on a regional scale.  It is shown that
its groundwater movement is closely approximated by direct flow and the tritium con-
tent in boreholes is related to tritium input in 2 areas of recharge.  The prelimin-
ary results indicate that the Sabi River is playing a greater part in the groundwater
regime of the alluvial plain than originally anticipated.  Velocity of movement of
the groundwater is deduced as 2-5ft/day.  The low level tritium counting system used
in the authors' laboratory is briefly described, and the limit and accuracy of meas-
urement is discussed.
68-69:02F-030
THE MECHANISM OF NATURAL GROUNDWATER RECHARGE AND DISCHARGE-1.  ONE-DIMENSIONAL,
VERTICAL, UNSTEADY, UNSATURATED FLOW ABOVE A RECHARGING OR DISCHARGING GROUND-WATER
FLOW SYSTEM,
Freeze, R. Allan.
Dept of Energy, Mines and Resources, Calgary, Alberta, Canada.
Water Resources Research, Vol. 5, No. 1, p 153-171, February 1969.  9 fig, 2 tab,
33 ref.

Descriptors:  *Unsteady flow, *Saturated flow, *Unsaturated flow, *Infiltration,
Mathematical models, Evaporation, Water-level fluctuations, Percolation, Recharge,
Discharge  (Water), Darcy's Law, Soil water movement, Groundwater movement. Rainfall
intensity.
Identifiers:  Transient flow.

The unsaturated flow processes of infiltration and evaporation are in physical and
mathematical continuity with the parallel saturated processes of recharge and dis-
charge.  Water table fluctuations result when the rate of groundwater recharge or
discharge is not matched by the unsaturated flow rate created by infiltration or
evaporation.  A water table rise provides the source of replenishment to the ground-
water zone that allows the prevailing rate of recharge to continue.  This dynamic
water table behavior can be simulated by a one-dimensional, numerical mathematical
model involving transient flow through an integrated saturated - unsaturated system.
The solutions are applicable to homogeneous, isotropic soils in which the functional
relationships show hysteresis properties.  The model allows upper boundary conditions
of constant rate rainfall, ponded water, evaporation, and redistribution.  It can be
used to determine the water table fluctuation that will arise from a given set of
initial conditions, boundary conditions, and soil type.  The effects of variations
in the parameters that control the flow are examined to arrive at a better under-
standing of the mechanism of natural groundwater recharge and discharge.
68-69:02F-031
DETERMINING THE RATIO OF HORIZONTAL TO VERTICAL PERMEABILITY BY AQUIFER-TEST
ANALYSIS,
Weeks, Edwin P.
Geological Survey, Madison, Wis.
Water Resources Research, Vol. 5, No. 1, p 196-214, February 1969.  6 fig, 1 tab,
22 ref.

Descriptors:  *Groundwater movement, *Permeability, Anisotropy, Aquifers, Beds,
Unsteady flow, Porosity, Interstices, Piezometers, Piezometry, Theis equation,
Drawdown, Water level fluctuations.
Identifiers:  Aquifer anisotropy, Vertical permeability, Horizontal permeability.
Aquifer testing, Pumping tests, Partially penetrating wells.

The ratio of horizontal to vertical permeability may be determined by analysis of
drawdown data from piezometers or partially penetrating observation wells near a
                                      29

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 partially penetrating production well.   The analyses are made by comparing measured
 drawdowns in the piezometers to those predicted if the production well  fully pene-
 trated the aquifer.   The differences between the measured and predicted drawdowns
 are determined,  and  the distances from the pumped well at which these differences
 would occur in an isotropic aquifer are determined from an equation.  The  permea-
 bility ratio is  computed as the square of the ratio of actual distances to computed
 distances.  The  ratio of horizontal to vertical permeability in glacial outwash  in
 central Wisconsin was determined from 5 aquifer tests to range from about  2 to about
 20.
 68-69:02F-032
 IDENTIFICATION OF NONLINEAR PARAMETERS OF  GROUNDWATER BASINS  BY HYBRID  COMPUTATION,
 Vemuri,  Venkateswararao,  and Karplus,  Walter  J.
 California University,  Los  Angeles.
 Water  Resources Research, Vol.  5,  No.  1, p 172-185,  February  1969.   8 fig,  13 ref.

 Descriptors:   *Groundwater  basins,  *Aquifers,  *Computer  models,  *Parametric hydrology,
 *Water table,  Analog  computers.  Digital computers, Data  processing,  Equations, Hydro-
 logic  data,  Transmissivity,  Input-output analysis, Systems  analysis, Boundaries
 (Surfaces),  California, Contours,  Storage  coefficient, Mathematical  models.
 Identifiers:   *Parameters,  *Hybrid  computers,  Algorithms, San Fernando  Valley, Calif-
 ornia.

 Identification of parameters of  an  unconfined  aquifer in which the dynamics of the
 water  table were describable by  a  partial  differential equation can  be  looked upon as
 a  control  system problem  in distributed parameters systems.   A maximum  principle was
 used in  conjunction with  a  steepest descent algorithm and the transmissibility of an
 aquifer  was  identified  starting  from observed  values of  input-output as data.  This
 algorithmic  procedure was blended with a heuristic method to  identify the storage
 coefficient and the boundary of  an  aquifer in  the San Fernando Valley basin in the
 city of  Los  Angeles.  Some  typical  results of  computations  carried out  on the hybrid
 computer were  presented.  This work demonstrates the computational advantages in com-
 bining analog  and digital hardware, not only  in terms  of the  gain in computational
 time but also  in terms  of the flexibility  offered by the system.
 68-69:02F-033
 DRAINING AREA UNDERLAIN BY  HIGHLY PERMEABLE  SHALLOW  SAND AQUIFER,
 Allen, R. R., and Myers, V.  I.
 Agricultural Research Service, Washington, D.C.
 Transactions of ASAE, Vol.  12, No.  1, p  29-31, January 1969.   6 fig, 5 ref.

 Descriptors:  *Aquifers, *Drainage  systems,  *Drains, *Tiles, *Subsurface drainage,
 Permeability, Sands, Texas,  Electrical resistance, Electrical  conductance, Analog
 models, Model studies, Water table, Flow measurement, On-site  data collections,
 Effluents, Soil water movements.

 This paper reports a field  and electrical resistance analog study of subsurface tile
 drainage of an area near Raymondville, Texas, where  the top of the sand aquifer was
 10 ft. below ground surface.  A subsurface tile drain, placed  8 ft. deep, yielded
 considerable effluent yet had a limited  effect on the water table.  Field and elec-
 trical analog data indicated that the underlying aquifer supplied 70 to 75% of the
 total tile flow.  It was suggested  that  successful water table control might be
 achieved.
68-69:02F-034
POINT DILUTION METHODS OF INVESTIGATING GROUND WATER FLOW BY MEANS OF RADIOISOTOPES,
Drost, Walter, Klotz, Dietmar, and Koch, Arnd.
Institut fur Radiohydrometrie, Munich, Federal Republic of Germany.
Water Resources Research, Vol. 4, No. 1, p 125-146, February 1968.  15 fig, 3 tab,
30 ref.

Descriptors:  *Tracers, *Radioactive isotopes, Dyes, Groundwater, *Wells, Dams, Per-
meability, Piezometers, Porous materials, Model tests, Underseepage, Field tests.
Seepage, Bibliographies, *Groundwater flow.
Identifiers:  Radiation detectors, Gold isotopes, Foregin testing. West Germany,
*Dilution method, *Water wells.


                                      30

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The distortion of the flow field by a well must be known to apply the point dilution
method of measuring groundwater flow by tracers.  The distortion can be calculated
if aquifer permeability is less than or equal to gravel pack permeability, and if
gravel pack permeability is less than or equal to well screen permeability.  The
tracer must be adequately mixed during the dilution procedure.  Experiences obtained
from model tests are applied to field investigations.  Peak-to-peak and total count
methods were used in wells having a vertical flow to determine depths and rates at
inflow and outflow.  The direction of groundwater flow was determined by the point
dilution method; a radioactive tracer is injected into the well screen water column
and measured by a collimated probe that is sensitive to the direction of incident
radiation.  Using tracers that are fixed on the soil is advisable; Gold 198 is the
most suitable tracer.  Strong, vertical currents in a well present a serious obstacle
to field measurements of the rate and direction of groundwater flow.
68-69:02F-035
DRAWDOWNS DUE TO PUMPING FROM STRIP AQUIFERS,
Bokhari,  S. M. H.,  Strachan, J. K., and Turner, A. K.
Irrigation & Power Dept, Govt. of West Pakistan, Lahore.
Journal of the Irrigation & Drainage Div, ASCE, Vol. 94, No. IR2, Proc.  Paper 5981,
p 233-242, June 1968.  4 fig, 1 tab, 7 ref.

Descriptors:  Drawdown, *Groundwater,  *Pumping, Strip aquifer, Water resources,
*Wells.

Drawdown patterns due to pumping from wells in long narrow  (strip)  aquifers are
dependent mainly on the type of side boundary  (recharge, impermeable).  A theoretical
solution is developed for an idealized confined aquifer with impermeable boundaries,
and the results compare favorably with those obtained from complementary tests using
a membrane analog.   Solutions are also given for the simpler case of recharge boun-
daries.  Either the mathematical or membrane solutions should be suitable for field
purposes, including certain conditions of unconfined flow.
68-69.-02F-036
CONJUNCTIVE USE OF GROUND AND SURFACE WATERS,
Doody, James J.
California State Dept of Water Resources, Los Angeles.
Journal of American Water Works Assn., Vol. 61, No. 8, p 395-397, August 1969.

Descriptors:  *Conjunctive use, *Model studies, *Mathematical models, *Groundwater
basins, *California, Optimization, Economics, Computer models, Digital computers.
Water management (Applied), Water resources development, Surface waters.
Identifiers:  Groundwater basin models.

Partial or total application of the methods will provide much of the data necessary
for making current management decisions as to the best way of meeting future water
demands.  Not only can a few arbitrarily selected operational plans be compared by
its use, but the tools are also provided whereby an optimum plan can be derived by
the local water agency.  The economic impact of various legal and political con-
straints on the optimum plan can also be evaluated.  Because this method is written
in general terms and preserved in computer programs, it permits rapid updating and
adjustment of operating criteria as conditions change, as more geologic and hydro-
logic information becomes available, and as experience is gained in actual opera-
tions.
68-69:02F-037
LAND SUBSIDENCE ALONG THE DELTA-MENDOTA CANAL, CALIFORNIA,
Prokopovich, N. P., and Herbert, D. J.
Bureau of Reclamation, Sacramento, California.
American Water Works Assn., Vol. 60, No. 8, p 915-920, August 1968.  11 fig.

Descriptors:  *Subsidence, *0verdraft, *California, *Canals, Drawdown, Water levels,
Irrigation water, Damages, Flooding, Submergence.
Identifiers:  Delta-Mendota Canal  (Calif.).
                                      31

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 Land subsidence caused by groundwater overdraft is changing the  gradient  of  the
 Delta-Mendota Canal,  California.   Bridges  are submerged  and the  canal  lining is  1-6
 ft.  lower than when it was installed in some locations.   Replacement of well water
 by canal water for irrigation has ended the overdraft, but continued lag  subsidence
 may be expected to amount to as much as 2  ft.  in the  next 25  years.
 68-69:02F-038
 THE  INVESTIGATION OF WATER FLOW THROUGH POROUS  MEDIUMS  BY  MEANS  OF  RADIOTRACERS,
 Ellis,  W.  R. ,  Kevi,  L.,  and Wiebenga,  W.  A.
 Australian Atomic Energy Commission Research  Establishment,  Lucas Heights, N.S.W.
 Water  Resources  Research, Vol.  4,  No.  2,  p  413-416,  April  1968.   2  fig,  1  tab,  6 ref.

 Descriptors:   *Groundwater movement,  *Dispersion,  *Tracers,  Hydraulic models, Poros-
 ity, Porous media,  Sands, Dupuit-Forchheimer  theory.
 Identifiers:   Bromine radioisotopes.

 The  radioisotope bromine 82 was used to measure the  flow of  water through  a packed
 sand column.   It was shown that the commonly  accepted Dupuit-Forchheimer assumption
 did  not apply  under  these conditions.   Some information was  also obtained  on lateral
 dispersion using iron gauzes and copper 64 solution.
 68-69:02F-039
 CONCEPTS  IN  GROUND  WATER MANAGEMENT,
 Mann, John F., Jr.
 Journal of American Water Works Assn., Vol.  60, No.  12, p  1336-1344, December 1968.
 22 ref.

 Descriptors:   *Groundwater, Groundwater mining, Water quality, Thermal pollution.
 Aquifers, Groundwater  flow, Groundwater movement, Groundwater basins, Groundwater
 recharge, Salinity,  Water reuse,  Filtration,  Quality control, Waste water treatment,
 Turbidity, Temperature  control, Waste water  disposal. Water  table, Bibliographies,
 Safe yield.
 Identifiers:   *Groundwater management, Artificial replenishment, Groundwater hydro-
 logy.

 The goals of groundwater  management are part  of a general  objective of serving pres-
 ent and future demands  for water  at minimum  cost and acceptable quality.  The goals
 should be coldly practical, recognizing that  almost  every  use of water results in
 some biological, chemical, or thermal deterioration.  In most basins, the goal is
 continued usability.  The trend is toward better control of  the amounts and patterns
 of extractions, augmenting recharge to ground storage, decreasing evapotranspirative
 waste or outflows that  go to waste, controlling mineral and  thermal pollution, in-
 tensifying use of groundwater storage, and avoiding  damage caused by high water
 tables or land-surface  subsidence.  Management objectives  are aided by powerful com-
 puter techniques  (developed mainly within the last 10 years) that predict and test
 the effects of many  assumptions on the groundwater body.
68-69 :02F-040
TRANSIENT FUNCTIONS FOR LAND DRAINAGE,
Jenab, S. A., Bishop, A. A., and Peterson, Dean F.
Utah  State University, Logan, Dept of Agricultural and Irrigation Engineering.
ASCE  Proc. , Journal of Irrigation & Drainage Div., Vol. 95, No. IR3, Pap 6768,
p 361-373, September 1969.  9 fig, 3 tab, 8 ref, append.

Descriptors:  *Drainage, *Runoff, *Infiltration, *0verland flow, *Mathematical
studies, Drainage effects. Drainage engineering, Drawdown, Diffusion, Transmissivity,
Water storage, Recession curves, Discharge  (Water).
Identifiers:  Land drainage.

Solution of the diffusion equation for a line sink in a plane yields the error func-
tion.  By superposition and integration, functions which describe the transient
position and rate of fall of a water table under artificial drainage are developed
for multiple drains.  These may be used to determine in situ values of transmissivity
and storage as well as for discharge.  A means of using the method for any initial
water table position is presented and some design examples are given.
                                      32

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68-69:02F-041
UNCONFINED AQUIFER CHARACTERISTICS AND WELL FLOW,
Esinaili, Houshang, and Scott, Verne H.
Engineering Science, Inc., Oakland, California.
American Society of Civil Engineers Proceedings, Journal of the Irrigation and Drain-
age Division, Vol. 94, No. IR1, Paper No. 5872, p 115-136, March 1968.  6 fig, 3 tab,
25 ref.

Descriptors:  *Groundwater movement, *Unsteady flow, *Aquifer characteristics, Hyd-
raulic conductivity, Storage coefficient, Darcy's law, Dupuit-Forchheimer theory,
Injection wells, Withdrawal.
Identifiers:  Unsteady radial flow.

Numerical solutions are developed for determination of aquifer characteristics and
unsteady radial flow through injection wells in unconfined aquifers under constant
drawdown and injection pressure conditions.  These solutions are based on a numerical
solution of the basic differential equation of flow.  Appropriate dimensionless para-
meters are introduced to transform the basic differential equation of flow into an
explicit form.  Dimensionless graphical solutions are presented for the rate and
accumulative volume of discharge and recharge and the radius of expansion of recharge
mounds versus time for a range of drawdown and injection pressure values.  Numerical
examples are presented by applying these solutions to hypothetical field conditions.
68-69:02F-042
AN AQUIFER TEST USED TO INVESTIGATE A QUALITY OF WATER ANOMALY,
Jorgensen, Donald G.
Geological Survey, Huron, South Dakota.
Ground Water, Vol. 6, No. 6, p 18-20, November-December 1968.  4 fig, 1 tab, 5 ref.

Descriptors:  *Water quality, *Groundwater,  Aquifers, Artesian wells, South Dakota,
Leakage.
Identifiers:  Aquifer tests, Avon  (South Dakota).

An aquifer test and analyses of water samples showed that the anomalous quality of
water in a municipal well in Avon, South Dakota was caused by leakage from a nearby
abandoned well tapping another aquifer.  The test used the city well and 1 observa-
tion well.  Analysis of test data indicated a transmissibility of 450gpd per ft be-
fore the cone of influence reached the recharge boundary and IVOOgpd per ft after
reaching it.  A graphical method located an image well in about the same area as a
50-yr-old capped city well.  The abandoned well was finished in the Dakota aquifer,
which has a higher potentiometric surface than the Codell aquifer, in which the city
well is finished.  Leakage of the casing of the old well is further indicated by
chemical quality of the water, which has about the composition and temperature of a
mixture of Codell and Dakota water.
68-69:02F-043
LATERAL MOVEMENT OF WATER THROUGH THE UNSATURATED ZONE OF AN UNCONFINED AQUIFER,
Mobasheri, Fereidoun, Shahbazi, M.,  and Todd, D. K.
California University, Los Angeles,  School of Engineering and Applied Science.
California University Water Resources Center Contribution No. 106, November 1965.
39 p, 10 fig, 3 tab, 12 ref, 2 append.

Descriptors:  *Unsaturated flow, *Aquifers, *Groundwater movement, *Model studies,
*Hydraulic models, Permeability, Water table, Analytical techniques, Interfaces,
Hydraulic conductivity, Moisture tension.
Identifiers.  Lateral unsaturated flow.

Unsaturated lateral flow in unco;,fined aquifers was studied by mathematical analysis,
sand-box, and sand-column moiel studies.  The hydraulic conductivity decreased as the
negative pressure of the porous media increased.  The calculated equivalent depth of
the -ansar.jrai.3d zone for the sand used in the investigation was 35 cm.  The flow rate
through unsaturated zone increased with a decreasing rate as the unsaturated zone
depth inci.iased while the hydraulic gradient was kept constant.  The rate of lateral
flew movement could also be calculated to a reasonable accuracy from flow net dia-
grams or the graphical integration of the area under a characteristic conductivity
curve.  An example of the application of the results can be shown by the determina-
tion of underflow at Cedar Springs Damsite in Southern California where flow through
unsaturated zone was neglected although the average depth of the aquifer was only

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 12 ft.  The material is predominantly medium-grained sand with lenses of gravel and
 cobbles.  As the average depth of the aquifer is 12 ft, the lateral flow through the
 unsaturated zone could amount to 11% of the total lateral flow.
 68-69:02F-044
 GEOCHEMICAL TRACING OF MINERAL WATER SOURCES IN THE SOUTH WESTERN DEAD SEA BASIN,
 ISRAEL,
 Maxor,  E.,  Rosenthal,  E., and Ekstein,  J.
 Weizmann Institute of  Science, Rehovoth (Israel).
 Journal  of  Hydrology,  Vol.  7, No.  3, p  246-275, March 1969.   8  fig,  3  tab,  21  ref,
 2 append.

 Descriptors:   *Geochemistry,  *Chemical  analysis, *Water chemistry,  *Mineral water,
 *Hydrogeology,  Sampling,  Water quality, Dossolved  solids,  Aquifer characteristics,
 Water temperature, Wells, Springs,  Thermal water,  Fresh water,  Saline  water, Salts,
 Lake basins,  Trace elements,  Radioactivity.
 Identifers:   *Israel,  Dead  Sea Basin.

 Chemical composition of thermal and mineral waters along the southwestern shores of
 the Dead Sea  was investigated.  Data included 108  chemical analyses  of different
 water samples,  taken from 36  wells  and  springs. Chemical  composition  of  the waters
 was used as  a tracing  tool  for the  determination of various  groups of  waters in the
 investigated  area.  Three distinct  water groups were found in the area.   The Kikar-
 Noit group waters  had  temperatures  ranging up to 42 deg C  and contained up  to  17g/l
 dissolved solids.   The Zohar-Yesha  group waters had temperatures  of  33 deg  C to 39
 deg C,  50-190g/l dissolved  solids,  and  up  to 40 mg/1 H sub 2 S.   The third  group con-
 sisted of fresh waters.   This report deals with the geographical  extension  of  the
 established water  groups  and  the mutual relations  between  them.
 68-69:02F-045
 ANALOG-DIGITAL  MODELS  OF  STREAM-AQUIFER SYSTEMS
 Moulder,  E. A.,  and  Jenkins,  C.  T.
 Geological  Survey, Denver,  Colorado.
 Ground Water, Vol. 7,  No.  5 p 19-24,  September-October  1969.   8  fig,  3  ref.

 Descriptors:  *Computer models,  *Analog models,  *Digital computers, *Surface-
 groundwater relationships,  Conjunctive  use, Model  studies,  Simulation analysis,
 Optimization, Water  management (Applied),  Streams, Aquifers,  Water demand, Water
 rights.
 Identifiers:  Hybrid computer models.

 The best  features of analog and  digital computers  were  combined  to make a management
 model of  a  stream-aquifer  system.  The  analog model provides  a means  for synthesizing
 verifying,  and  summarizing  aquifer properties; the digital  model permits rapid cal-
 culation  of the  effects of  water-management practices.  Given specific management
 alternatives, a  digital program  can be  written that will optimize operation plans
 of stream-aquifer systems.  The  techniques are demonstrated by application to a study
 of the Arkansas  River  Valley  in  southeastern Colorado.
68-69:02F-046
CHEMICAL CHANGES IN TILE-DRAIN FILTERS AND DITCH BANKS CAUSED BY ANAEROBIOSIS,
Ford, H. W., and Seville, B. C.
Citrus Experiment Station, Lake Alfred, Florida.
Transactions of the American Society of Agricultural Engineers, Vol. 11, No. I, p 41-
42, January-February, 1968.  1 tab,.8 ref.

Descriptors:  Drainage, *Tile drainage, Drainage system, *Soii chemical properties.
Ditches, Backfill, Filters, *Sav.'dust, Hydrogen sulfide, Iron compounds, Anaerobic
conditions, *Iron bacteria.
Identifiers:  *Slag.

The rapid destruction of slag gravel filters under continuous flow was initiated by
H2S, a bacterial metabolite formed under suitable conditions in an anaerobic flooded
environment.  Bisulfide ions apparently reacted with calcium in the slag, destroying

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the buffering capacity as well as physical structure.  FeS accumulated as deposits
around slag and sawdust filters and may be the principal factor reducing infiltra-
tion rates.  Heavy deposits in the soil were present only on topsoil organic matter
used to "blind" the tile.  FeS observed in the surface of seepage zone of ditch banks
may have an adverse effect on hydraulic conductivity.
68-69.-02F-047
GROUND WATER MANAGEMENT AND RECLAIMED WATER,
Owen, L. W.
Orange County Water District, Santa Ana, California.
Journal of American Water Works Association, Vol. 60, No. 2, p 135-144, February 1968.
2 fig, 1 tab.

Descriptors:  *Ground water, Waste water (Pollution), Reclaimed water, Water manage-
ment  (Applied), Water reuse, Water supply.

Studies by the Orange County Water District have attempted to view the overall water
management problem and develop a program to meet reasonable objectives.  In order to
understand the contemplated use of wastewater reclamation in this or any area, the
overall water requirement and supply problems have been evaluated.  With the six
water sources and technologic capability available to the Orange County Water District;
there are many possible ways to meet water quantity and quality requirements.  The
challenge is to find the most economical method consistent with public safety.  The
future role of wastewater reclamation will depend upon the need, feasibility, and
economics of the treatment process.
68-69.-02F-048
MOVEMENT OF SALT IN SATURATED SOILS COLUMNS,
Mokady, R. S., Ravina, I., and Zaslavsky, D.
Israel Institute of Technology, Haifa.
Israel Journal of Chemistry, Vol. 6, p 159-165, 1968.  3 fig, 3 ref.

Descriptors:  *Saturated soils, *Salts, *Calcium chloride, Porous media clays,
Chromatography, Hydrodynamics.
Identifiers:  Malkia clay soil.


The leaching of salts through porous media is described using the theory of hydro-
dynamic dispersion on chromatography.  Calcium chloride solutions were passed
through a saturated non-expanding clacium clay soil.  The breakthrough curves were
found to depend on the CaC12 concentrations and on the rate of flow.  The results
are explained by ion exclusion and hydrodynamic dispersion mechanisms.


68-69:02F-049
THEORY OF FLOW IN AQUICLUDES ADJACENT TO SLIGHTLY LEAKY AQUIFERS,
Neuman, S. P., and Witherspoon, P. A.
California University, Berkeley, Department of Civil Engineering.
Water Resources Research, Vol. 4, No. 1, p 103-112, February 1968.  5 fig, 14 ref.

Descriptors:  *Groundwater,  *Aquifers, *Aquicludes, Wells, Drawdown.
Identifiers:  *Hydrologic systems, Theis solution.

The theory of flow in aquicludes that are adjacent to slightly leaky aquifers is pre-
sented for two cases:  (a) aquicludes of finite thickness, and (b) aquicludes of
semi-infinite thickness.   By slightly leaky, we simply mean that when the aquifer is
being pumped at constant rate, the drawdowns in the aquifer will be predicted by the
Theis solution, even though some slight movement of water through adjacent confining
beds occurs.  It is assumed that flow is essentially horizontal in the aquifer and
vertical in the aquiclude.  On this basis, analytical expressions for drawdown in
the aquiclude are developed for each case.  The results are presented in the form of
type curves that can be used for aquiclude evaluation.  The effect of multiple-well
fields is considered in each case.
                                      35

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68-69:02F-050
AGRICULTURE'S EFFECT ON NITRATE POLLUTION OF GROUNDWATER,
Stewart, B. A., Viets,  F. G., and Hutchinson, G. L.
Agricultural Research Service, Fort Collins, Colorado.
Journal of Soil and Water Conservation, Vol. 23, No. 1, p 13-15, January-February
1968.  1 fig, 1 tab, 8  ref.

Descriptors:  *Nitrate, *Water pollution, *Fertilizers, *Soil profiles, *Groundwater,
*Agriculture, *Wastes,  Alfalfa, Grasslands.
Identifiers:  Irrigated row crops. Domestic wells, Feedlots.

Contributions of fertilizers applied to soil and wastes from concentrated livestock
feeding operations to pollution of groundwater were studied in the middle South
Platte River Valley in Colorado.   Amounts of nitrate moving through 129 soil profiles
studied varied widely with land use.  Average total nitrate N to a depth of 20 ft in
Ibs/acre was 1436 under feedlots, 506 under irrigated row crops, 261 under dryland
row crops, 90 under native grassland, and 79 under alfalfa.  The average annual loss
of N to groundwater under irrigated row crops was estimated at 25 to 30 Ibs/acre.
Feedlots located near homesteads had much more effect on nitrate content of water
from domestic wells than did cropped land.
                                      36

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                                      SECTION V


                      WATER CYCLE - WATER IN SOILS  (Group 02G)


68-69:02G-001
DISPERSION AT THE INTERFACE OF MISCIBLE LIQUIDS IN A SOIL,
Li, W. H., and Yeh, G. T.
Syracuse University, Syracuse, New York.
Water Resources Research, Vol. 4, No. 2, p 369-377, April 1968.  7 fig, 10 ref.
 (See 68-69:02F-001)
68-69:02G-002
ENTRY VELOCITY CONTROL LIMITS DRAIN SEDIMENTATION,
Willardson, L. S., Fouss, J. L., Reeve, R. C., and Fansey, N. R.
Agricultural Research Service, Brawley, California.
Journal of the Irrigation & Drainage Division, ASCE, Vol. 94, No. IR4, December 1968.
4 fig, 1 tab, 10 ref.
(See 68-69:02F-003)
68-69:02G-003
INFILTRATION RATES AS AFFECTED BY DESERT VEGETATION,
Lyford, Forest P., and Qashu, Hasan K.
Arizona University, Tucson.
Water Resources Research, Vol. 5, No. 6, p 1373-1376, December 1969.  3 fig, 3 tab,
4 ref.

Descriptors:  *Infiltration, *Vegetation effects, *Arid lands, Soil-water-plant rela-
tionships, On-site tests, Soil water movement.
Identifiers:  Paloverde, Creosote bush.

Infiltration of water into two soils measured at radial distances from the stems of
paloverde  (Cercidium microphyllum) and creosote bush  (Larrea tridentata) were found
to average nearly three times greater under plants than in the openings.  Bulk den-
sity was lower and organic matter content was higher  in topsoil under plants than in
the openings.
68-69:02G-004
IRRIGATION INVESTIGATIONS IN OTAGO, NEW ZEALAND, IV. PHYSICAL PROPERTIES OF SOILS OF
THE ARROW BASIN AND UPPER CLUTHA VALLEY,
Rickard, D. S., and Cossens, G. G.
Winchmore Irrigation Research Station, Private Bag, Ashburton, Dept of Agriculture.
New Zealand Journal of Agricultural Research, Vol. 11, p 701-732, 1968.  5 fig,
11 tab, 4 ref.

Descriptors:  *Soil physical properties, *Irrigation, *Soil horizons, Rainfall,
Available moisture, Wilting point, *Soil analysis.
Identifiers:  New Zealand, *yellow-brown earth, *yellow-grey earth.

Physical properties, including the percentage of fine particles, organic carbon, 15-
bar retention, field capacity, and available moisture show consistent increases be-
tween virgin soil groups formed under semi-arid  (brown-grey earths), sub-humid  (yellow
-grey earths), and humid  (yellow-brown earths) climates.  Bulk density values dec-
rease throughout the same sequence.  There is a tendency for similar changes to occur
with soils of increasing ground surface age within the brown-grey earths.  There is
an insufficient range of ground surface ages to establish this tendency for the other
groups.  Irrigation and associated management have tended to alter the properties of
a particular soil group in the direction of those of the group formed under a higher
rainfall.  This tendency is not true for the bulk density, which is in most cases
higher under irrigation.  The available moisture held in the top 12 in. of the soils
studied ranged from 1.58 in. to 4.30 in.  If irrigation was applied at the wilting
point, the soils in the three zonal groups would retain the following approximate
amounts:  brown-grey earths, 2 in. to 2^ in.; yellow-grey earths, 2^ in. to 3h in.;
yellow-brown earths, 3 in. to 4 in.
                                      37

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 68-69:02G-005
 DRAINAGE  WITH  PERFORATED PLASTIC  TUBING,
 Klock,  G.  0.,  Boersma,  L.,  Watts,  D.  G.,  and  Brooks,  R.  H.
 Forest  Hydrology Laboratory,  Wenatehee, Washington.
 Agronomy  Journal,  Vol.  61,  No.  1,  p 56-68,  January-February,  1969.   3  fig,  1  tab,
 4  ref.

 Descriptors:   *Drainage,  *Subsurface  drainage,  *Alfalfa,  *Manganese, *Water table.
 Identifiers:   Plastic  tubing.

 The  feasibility  of placing  drains at  shallow  depths and  close together to improve
 drainage  conditions on  a planosol was evaluated.   Field  lysimeters were obtained by
 surrounding  soil blocks with  vertical sheets  of heavy plastic penetrating well into
 the  impermeable  subsoil.  Perforated  plastic  tubing placed  22.5  feet (approx. 6.9 m)
 apart at  a depth of 20  inches  (approx.  51 cm) provided adequate  drainage.  Dupuit
 alfalfa yielded  better  than 10  T/A dry matter.  Manganese levels were below concen-
 trations  considered toxic.  When  a spacing  of 45.0 feet  (approx. 13.7 m) was  used,
 the  alfalfa  yields were greatly reduced,  and  the manganese  concentrations were well
 above levels considered toxic.
 68-69:02G-006
 TRANSPORT  IN SOILS:  THE BALANCE OF MOMENTUM,
 Raats, P.  A. C., and Klute, A.
 Agricultural Research Service, Madison, Wisconsin.
 Soil Science Society of America Proceedings, Vol. 32, No. 4, p 452-456, July-August,
 1968.  30  ref.

 Descriptors:  *Soil physics, *Darcy's Law, *Soil moisture, *Flow, *Momentum equation,
 Saturated  soils, Unsaturated flow.
 Identifiers:  *Balance of  forces, *Deformable soils, Continuum theory.

 The mechanics of the fluid phase(s) of a  soil is discussed on the basis of a balance
 of momentum for each phase.  Saturated as well as unsaturated soils are considered.
 It is shown that with certain assumptions the balance of momentum for a fluid phase
 reduces to Darcy's Law.  The meaning and  some possible generalizations of the various
 assumptions are considered.  The form of  Darcy's Law appropriate to soils whose solid
 phase undergoes a deformation is deduced.
68-69:02G-007
EFFECT OF WATER TABLE DEPTH AND FLOODING ON YIELD OF MILLET,
Williamson, R. E., Wiley, C. R., and Gray, T. N.
U.S. Department of Agriculture, Raleigh, North Carolina.
Agronomy Journal, Vol. 61, No.  2, p 310-313, March-April, 1969.  4 fig, 2 tab, 16 ref.

Descriptors:  *Drainage, *Aeration, Flooding.

Yields of millet  (Pennisetum glaucum  (L.)R. Br.) grown in both sheltered and nonshel-
tered soil tanks increased with water table depth to a depth of 76 cm.  In the shel-
tered tanks yields were similar for all water table depths greater than 61 cm.  The
N, P, and K contents of plants  grown with water tables at 15 or 30 cm in the shel-
tered tanks were significantly  lower than for deeper water table depths.  Except for
the tanks with 15- and 30-cm water tables, the oxygen content by volume was generally
above 18% at the 15-cm depth, indicating that the region of greatest root mass (0 to
8 cm) was probably well aerated.  Since yields were affected by water table depths
down to 76 cm, it appears that  the few roots extending below the 8-cm depth were
nevertheless necessary to supply nutrients to the plant.  Yield data suggest that 02
was low in a portion of the root zone where water tables were less than 76 cm below
the surface.  Two days of flooding 4 weeks before the first harvest reduced the first
harvest yield 40%, but did not affect the second harvest yield.  Flooding at earlier
or later dates caused less yield reduction.
                                       38

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  68-69:020-008
 INTERDEPENDENCE OF WATER DROP ENERGY AND CLOD SIZE ON INFILTRATION AND CLOD STABILITY,
 Moldenhauer, W. C., and Kemper, W. D.
 Iowa State University, Ames, Dept of Agronomy.
 Soil Science Society of America Proceedings, Vol. 33, No. 1, p 297-301, January
 February, 1969.  8 fig, 3 tab, 17 ref.

 Descriptors:  *Infiltration, *Impact  (Rainfall), *Soil structure, *Soil surface,
 *Runoff, Soil erosion.
 Identifiers:  Soil surface sealing.

 The decline of intake rates as successive increments of water drop energy were applied
 to various sizes of soil fragments of two Iowa and two Colorado soil types is present-
 ed.   There was a wide spread between intake rate of the 8- to 20-mm size range and
 those of all other sizes after the first increment  (1.25 cm as 5-mm drops) was applied.
 The intake rate of the 8- to 20-mm size declined rapidly after the first or second
 increment.  Final intake rates were not correlated with aggregate stability in this
 study.  There was a negative correlation between clay content and final intake rates.
 Final intake rates after disintegration of large soil fragments in many cases were
 lower than when initial size ranges were small.
68-69:02G-009
THE PREDICTION OF EVAPORATION, DRAINAGE, AND SOIL WATER STORAGE FOR A BARE SOIL,
Black, T. A., Gardner, W. R., and Thurtell, G. W.
Wisconsin University, Madison, Dept of Soil and Water Science.
Soil Science Society of America Proceedings, Vol. 33, No. 5, p 655-660, September -
December, 1969.  8 fig, 18 ref.

Descriptors:  *Evaporation,  *Drainage, *Infiltration, *Soil moisture, Capillary
action, Lysimeters, Irrigation, Deep percolation, Diffusivity, Water storage, Water
loss. Soil water.
Identifiers:  Plainfield sand, Conductivity.

Evaporation, drainage, and changes in storage for a bare Plainfield sand were measured
with a lysimeter during June, July, and August, 1967, under natural rainfall condi-
tions.  Cumulative evaporation at any stage was proportional to the square root of time
following each heavy rainfall.  The drainage rate was found to be an exponential func-
tion of water storage.  Both relations can be predicted from flow theory with knowl-
edge  of soil capillary conductivity, diffusivity, and moisture retention characteris-
tics.  Using these two relations and daily rainfall data, the water storage in the top
150 cm was predicted over the season to within 0.3 cm.
68-69:02G-010
RELATION OF WATER APPLICATION TO EVAPORATION AND STORAGE OF SOIL WATER,
Gardner, H. R., and Gardner, W. R.
Agricultural Research Service, Fort Collins, Colorado.
Soil Science Society of America Proceedings, Vol. 33, No. 2, p 192-196, March - April,
1969.  8 fig, 1 tab, 7 ref.

Descriptors:  *Evaporation, *Water storage, *Diffusivity, Rainfall, Irrigation.
Identifiers:  Rago loam, McGrew sandy loam.

Evaporation was measured from columns of Rago loam and McGrew loamy sand, to which
water had been added at several rates ranging from 0.25 cm/day to 10.2 cm every 20
days.  The water lost by evaporation varied from 100% of the total applied for the
smallest and most frequent addition to 31.2% for thf: 10.2 cm of water added to McGrew
soil every 20 days.  The losses from repeated cycles of the individual treatments
tended to approach a constant value that was less than the potential loss.  As the
amount added was increased for a given evaporation period, the loss tended to approach
a constant value that also was rruch less than the potential loss.  The cumulative
evaporation curves were scaled to dimensioniess variables and compared with a theoret-
ical solution of the diffusivity equation for finite media.  Using this scaling-com-
parison technique, the losses frcm sail with two different potential evaporations were
comoared with predicted curves.
                                      39

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 68-69:02G-011
 FACTORS  IMPORTANT IN  THE CALCULATION OF  HYDRAULIC  CONDUCTIVITY,
 Kunze, R.  J.,  Uehara,  G.,  and  Graham,  K.
 Michigan State University,  East Lansing,  Dept of Soil  Science.
 Soil  Science Society  of America Proceedings,  Vol.  32,  No.  6,  p  760-765,  November-
 December,  1968.   8  fig, 1  tab,  12  ref.

 Descriptors:   *Soil moisture,  *Hysteresis,  Pressure  head,  Computer.
 Identifiers:   Millington-Quirk  method, Matching  factor.

 The calculation of  hydraulic conductivity by  a modified Millington-Quirk method with
 a  matching factor gave conductivity values  closely approximating  experimentally
 measured values.   The  technique requires  knowledge of  the  moisture characteristic
 and the  saturated conductivity.  A number of  factors that  affect  the calculated
 values and improve  the computational results  were  investigated.   Calculated conduc-
 tivity values  decreased with an increasing  number  of pressure classes at low moisture
 contents.   For all  soils tested, the calculated conductivities were less than the
 experimental values at the  terminal point of  the moisture  characteristic.  This dis-
 crepancy was partially corrected by a  small change in  the  Millington-Quirk equation,
 by extending the  moisture  characteristics to  higher  suction values, and  by reducing
 the number of  pressure classes  to  approximately 10.  A matching factor,  the ratio of
 measured over  calculated saturated conductivity, was found necessary for obtaining
 the best fit of  calculated  and  measured data.  Two conductivity functions calculated
 separately from  each moisture characteristic  forming a hysteresis loop converged as
 the hysteresis loop was translated to  higher  tensions.  All computations were done
 by computer.
 68-69:02G-012
 SOIL MOISTURE CONTENT,  TILTH, AND  SOYBEAN RESPONSE WITH  SURFACE AND SUBSURFACE
 DRAINAGE,
 Fausey, N. R., and  Schwab, G. D.
 Agricultural Research  Service, Wooster, Ohio.
 Agronomy Journal, Vol.  61, No. 4,  p  554-557, July-August, 1969.  5 fig, 5 ref.

 Descriptors:  *Penetration, *Soil  moisture, *Subsurface  drainage, *Surface drainage.
 Identifiers:  Soil  crust, Soybean  yield, Soybean roots.

 Soil properties and soybean response were compared for plots having different levels
 of drainage.  The plots were established on a silty clay lakebed soil in northern
 Gh±o.  The soil and crop characteristics compared were:  (1) average soil moisture
 content at four depths  in the upper  30 cm during the seedbed preparation period
 (April and May);  (2) soil tilth immediately preceding seedbed preparation as express-
 ed by crust properties  and resistance to surface penetration; and (3) stand estab-
 lishment, root and  top  growth, and soybean yield.  On plots with no drainage, crop
 stand was sparse and crop growth essentially nil.  There were long periods with
 ponded water, and crusting and adverse structure of the  surface soil were much in
 evidence.  Among drained plots, there were no measurable differences in crust bulk
 density and soybean stand.  Plots  having subsurface or combined surface-subsurface
 drainage had lower moisture content, less resistance to  surface penetration, smaller
 crust units, taller plants, better developed root systems, and greater yields than
 plots with surface drainage alone.
68-69:02G-013
EXPERIMENTAL EVALUATION OF INFILTRATION EQUATIONS,
Skaggs, R. W., Huggins, L. E., Monke, E. J., and Foster, G. R.
Purdue University, Lafayette, Indiana, Dept of Agricultural Engineering.
American Society of Agricultural Engineers, 1968 Annual Meeting, Paper No. 68-213,
Logan,  Utah  June 1968.  26 p, 6 fig, 3 tab, 18 ref.

Descriptors:  *Infiltration, *Experimental data, Analysis, Soils, Time, Soil erosion,
Surface runoff, Bibliographies, Erosion, Field tests, Soil moisture,  Soil physical
properties, Runoff, Soil science, Agriculture, Hydrology.
Identifiers:  Evaluation, Rainfall-runoff relation, *lnfiltration rate, Equations,
Rainfall simulators, Wetting front, Regression analysis.

Ar. analysis of infiltration equations proposed by Green and Ampt, Hortan, Phillip,
       Ltan ',-::--S made using experimental data obtained in erosion studies with a plot

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size rainfall simulator.  An overland flow analysis was used to determine the infil-
tration rate-time relationship from the runoff hydrograph.  Regression fits of the
four equations to experimental data for 52 tests on 13 soils showed that all of the
equations adequately described the infiltration rate-time relationship.  Values of
the equation parameters for each run analyzed are presented in the paper.
68-69:02G-014
SOLVING THE NON-LINEAR DIFFUSION EQUATION FOR THE RADIAL FLOW OF WATER TO ROOTS,
Passioura, J. B., and Cowan, I. R.
C.S.I.R.O., Division of Land Research, Canberra City, A.C.T., Australia.
Agricultural Meteorology, Vol. 5, p 129-134, 1968.  3 fig, 6 ref.

Descriptors:  *Diffusion, *Soil water movement, *Flow, *Root systems, Model studies.
Identifiers:  *Radial flow.

The non-linear diffusion equation for the radial flow of water to a root can be
solved approximately by assuming that 39/3t is either zero (steady state) or constant
(steady rate).  The accuracy of such solutions has been in doubt, so they are here
compared with exact solutions obtained numerically.  It is shown that the approximate
solutions agree well with the numerical ones for biologically possible conditions.
The "steady rate" method is somewhat more accurate than the "steady state" one.
68-69:02G-015
TILLAGE INFLUENCES WATER INTAKE,
Burwell, R. E., Sloneker, L. L., and Nelson, W. W.
Agricultural Research Service, Morris, Minnesota.
Journal of Soil & Water Conservation, Vol. 23, No. 5, p 185-187, September-October,
1968.  3 tab, 9 ref.

Descriptors:  Cultivation, *Soil surfaces, *Infiltration, *Runoff, *Weathering, Soil
treatment, Loam, Clay loam, Soil texture, Soil erosion, Soil moisture, Mulching,
Water storage, Artificial precipitation.
Identifiers:  *Roughness (Soil), Sealing.

The studies were conducted to determine the influence of different tillage methods on
soil surface condition and subsequent infiltration.  Artificial rainfall was applied
at the rate of 5 inches per hour to various surface conditions on loam, clay loam and
sandy clay loam.  Surface conditions were created by moldboard plowing, moldboard
plowing-disking-harrowing,  rotary tillage and mulch tillage.  Infiltration before
runoff started on freshly-tilled bare surfaces increased as tillage-induced random
roughness increased.  Infiltration was not closely related to this roughness after
rainfall or fall-to-spring weathering caused surface seal development.  Infiltration
before runoff began was twice as high on freshly plowed surfaces as on freshly
plowed-disked-harrowed surfaces.  Fall mulch-tilled surfaces provided eight times
greater infiltration capacity before runoff started and four times greater infiltra-
tion during runoff the following spring than did fall plowed surfaces which were
disked and harrowed in the spring.  The tillage-infiltration relationships that were
studied could possibly be used to increase infiltration and reduce the runoff from
arid soils.
68-69:020-016
PSYCHROMETRIC MEASUREMENT OF SOIL WATER POTENTIAL IN SITU UNDER COTTON PLANTS,
Lang, A. R. G.
Commonwealth Scientific and Industrial Research Organization, Griffith (Australia).
Soil Science, Vol. 106, No. 6, p 460-464, December 1968.  4 fig.

Descriptors:  *Soil moisture, Soil water movement, *Moisture content, *Cotton,
*Hygrometry, Soil-water-plant relationships, Root systems, *Measurement,  Instrumen-
tation, Moisture uptake, Variability, Temperature, Absorption, Diurnal, Nocturnal,
Translocation.
Identifiers:  *Soil water potential, Water potential, *Psychrometers.

Water potentials were measured directly and continually at 9 different positions in
16 liter volumes of soil, while water was removed via the roots of intact cotton
plants in Australia.  Measurements were made using Spanner thermocouple psychrometers
                                     41

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 inserted into cages previously buried in the soil.   Water  potentials  displayed  the
 expected patterns:  water potential decreased more rapidly  during the  day  than night,
 while day by day it decreased.  The results  confirmed by direct measurement  that
 cotton plants continue to withdraw water from soils  at soil  water potentials less
 than -3000J kg super -1.  The apparatus, which may have application in  the field, and
 the variability of  results were discussed in detail.   Part of  the variability was
 probably caused by  uneven distribution of roots.   The probable error  of the  mean
 water potential at  a given time was small relative to the  changes in  water potential
 with time.
 68-69:02G-017
 ADSORPTION  OF  SODIUM FROM IRRIGATION WATER BY  FOUR TEXAS  SOILS,
 Thomas,  Grant  W.,  and Yaron,  Bruno.
 Texas  A&M University,  College Station.
 Soil  Science,  Vol.  106,  No.  3,  p  213-219,  September 1968.   6  fig,  4  tab.

 Descriptors:   *Sodium, Alkaline water,  *Adsorption,  Saline  water,  *Soil chemistry,
 Leaching, Electrolytes,  Chromatrography, Equilibrium, Mineralogy,  *Irrigation water,
 *Cation  exchange,  Clay minerals,  Flow rates, Texas,  Hydraulic  conductivity.
 Identifiers:   *Soil  columns.

 The adsorption of  sodium from saline water  during  flow  through chromatographic col-
 umns was  studied utilizing four soil types  from Texas having different soil mineral-
 ogy texture and cation exchange capacity.   Eight synthetic  and two natural well
 waters were used to  leach the soils.  It was concluded  that the relationship between
 SAR and  ESP of soil  did  not  give  a significant correlation  when sodium containing
 water  flowed through soil columns.   The exception  was the surface of the soil.  The
 total  electrolyte  concentration of the  sodic water influenced  the rate of sodium
 adsorption.  At equilibrium  soil  mineralogy and the  cationic composition exerted a
 greater  influence  over the exchangeable sodium percentages.  Mica and montmorillon-
 itic soils had a greater affinity for Na than did  montmorillonitic soils.  Flow of
 water  in  field conditions from  equilibrium  hydraulic conductivity could not be deter-
 mined .
68-69:02G-018
ANALYSIS OF VARIATIONS IN  SOIL MOISTURE STORAGE IN ROW CROP PLANTINGS AS A FUNCTION
OF AGROMETEOROLOGICAL FACTORS,
Kleshchenko, A. D., and Chirkov, Yu.  I.
State Hydrological Institute, Leningrad  (USSR).
Soviet Hydrology Selected  Papers No.  3, p 270-277, 1968.  3 tab, 11 ref., Translated
from Trudy Gidro-meteorologcheskogo nauchno-issledovatel' skogo tsentra SSSR, No. 14,
p 107-116, 1968.

Descriptors:  *Soil moisture, * Soil-water-plant relationships, *Water storage, *Vege-
tation effects, *Meteorology, Correlation analysis, Regression analysis, Evapotrans-
piration, Moisture content,  Statistical methods, Correlation analysis, Regression
analysis.
Identifiers:  USSR.

Meteorological observations  in Moscow and Kaluga provinces were related to soil mois-
ture content and row crop  data by multiple regression analysis.  The meteorological
data used were air temperature, relative humidity, moisture deficit, wind force,
clouds, number of days  with precipitation, and the amount of precipitation.  Crop
data were leaf surface area, density of planting, stage of plant development and soil
moisture, in corn and potatoes.  Correlation coefficients were calculated and tabula-
ted.  The variation in soil moisture was determined mainly by precipitation, number
of rainy days, and cloudiness, and less by the stage of plant development, initial
moisture and wind velocity.
68-69:02G-019
SOIL HYDRAULIC CONDUCTIVITY AS AFFECTED BY SODIC WATER,
Yaron, Bruno, and Thomas, Grant W.
Texas A&M University, College Station.
Water Resources Research, Vol. 4, No. 3, p 545-552, June 1963.
6 fig,  3 tab,  12 ref,
                                      42

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Descriptors:  *Hydraulic conductivity, Water quality, Permeability, Pervious soils,
Porosity, *Saturated flow, Soil chemical properties, Soil water movement, *Soil
water, Irrigation, Bentonite, Expansive clays, Expansive soils, Ion exchange, Leach-
ing.
Identifiers:  *Sodic water, Swelling clays, NA-bentonite, Experimental soil systems.

The hydraulic conductivities of mixtures of soil and glass beads in columns were de-
termined during the flow of dilute sodium-calcium solutions through the mixtures.
Flow was continued until equilibrium was achieved.  A curvilinear decrease in hydrau-
lic conductivity was found as the exchangeable sodium approached equilibrium.  The
shape of the curve depended on the nature of the soil and the cationic composition
and total salt content of the solutions.  The hydraulic conductivity became constant
only when a constant exchangeable sodium content was achieved along the soil column.
A semiempirical method of predicting the hydraulic conductivity was developed.
Agreement between calculated and observed values was found to be reasonably good.
68-69:020-020
A NUMERICAL METHOD FOR ESTIMATING INFILTRATION, REDISTRIBUTION, DRAINAGE AND EVAPOR-
ATION OF WATER FROM SOIL,
Hanks, R. J., and Klute, A.
Agricultural Research Service, Fort Collins, Colorado.
American Society of Agricultural Engineers, Annual Meeting, Paper No. 68-214, Logan,
Utah, June 1968.  16 p, 7 fig, 1 tab, 8 ref.

Descriptors:  *Numerical method, * Infiltration, Drainage, *Evaporation, Moisture con-
tent, Soils, *Soil moisture, Computer programming, Boundary values, Hysteresis, Water
table, Diffusion, Soil science, Wetting and drying tests.
Identifiers:  Soil columns, Soil moisture movement, One-dimensional, *Soil-water re-
lationship, Potential evaporation, Conductivity.

A numerical method was developed for estimating one-dimensional infiltration of water
into soil where water added by precipitation at the surface was equal to or greater
than the infiltration rate.  The method estimated redistribution of water within the
soil after precipitation had stopped, taking into account hysteresis in the water
content-pressure relation.  Drainage into a water table was considered.  The method
allowed for evaporation at a rate determined by external climatic conditions or at a
rate determined by internal soil conditions.  Graphs are given of:  (1)  water content-
pressure relations; (2) cumulative flow-time relations and water content profiles for
an infiltration, redistribution, evaporation problem;  (3) water content profiles
after redistribution,  using wetting and drying curves with and without hysteresis;
and  (4) cumulative flow, water content profiles, and pressure profiles for a drainage
evaporation problem.
68-69:02G-021
SALT AND WATER BALANCE, COACHELLA VALLEY, CALIFORNIA,
Bower, Charles A., Spencer, James R., and Weeks, Lowell O.
Agricultural Research Service, Riverside, California.
Journal of Irrigation & Drainage Division, ASCE, Vol. 95, No. IR1, Proc Paper No.
6437, p 55-64, March 1969.  2 fig, 4 tab, 6 ref.

Descriptors:  *Irrigated land, *Drainage effects, *Salt balance, *Water balance,
*Leaching, Drainage water, Irrigation effects. Drains, Salts, California, Arid lands,
Evapotranspiration, Soil chemistry. Tile drains, Input-output analysis, Ions.
Identifiers-  *Coachella Valley, California, Salt balance index.

This study reported salt and water balance conditions in irrigated land by years for
the period 1957-1965, and compared measured and calculated values for leaching and
evapotranspiration, as well as indicating nature and extent of chemical reactions
occurring in soil as a consequence of irrigation.  The salt balance index (output/
input) for irrigated land was highly related to both area of irrigated land having
tile drainage and leaching percentage, the index becoming close to one when about
half the land became tiled and when leaching percentage increased to about 30.  At
salt balance evapotranspiration, taken as the difference between depths of applied
and drainage water, agreed within about 10% of that calculated by the Blaney-Criddle
formula.  About 10% of the applied salt appeared to precipitate in soil largely as
calcium carbonate and magnesium in water replaced exchangeable sodium in soil during
irrigation operations.
                                     43

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 68-69:020-022
 THE  VERTICAL MOVEMENT  OF WATER IN  STRATIFIED  POROUS MATERIAL.   1.  INFILTRATION,
 Childs,  E.  C.,  and  Bybordi,  M.
 Agricultural Research  Council,  Cambridge  (England).
 Water  Resources Research,  Vol.  5,  No.  2,  p  446-459, April  1969.  9 fig, 1 tab,
 14 ref.

 Descriptors:   *Infiltration,  *Soil water  movement, *Unsaturated  flow, Soil profiles,
 Permeameters,  Mathematical models, Percolation, Model  studies,  Hydraulic models.
 Identifiers:   Heterogeneous  soil profiles.  Vertical permeability.

 The  infiltration law of  Green and  Ampt is extended to  include heterogeneous profiles.
 Formulas are developed to  express  3 relationships.  The  infiltration law is derived
 for  a  profile  consisting of  a succession  of n different  layers with conductivity de-
 creasing from  the surface.   An expression is  derived for the conductivity profile
 that will give  a specified infiltration law,  and  in particular  a linear infiltration
 law  with specified  parameters.  This expression serves to  determine the conductivity
 when the infiltration  law  is  observed.  Experiments are  described  to measure the in-
 filtration  rates into  layered columns  or  porous material,  the results of which con-
 firm the theory.
 68-69:02G-023
 SUBSURFACE DRAINAGE BY TRANSIENT-FLOW THEORY,
 Dumm, Lee D.
 Bureaufcof Reclamation, Denver, Colorado.
 ASCE P|BC., Journal of Irrigation & Drainage Division, Vol. 94, No. IR4, Paper No.
 6315, p 505-519, December 1968.  12 fig, 6 tab, 13 ref.

 Descriptors:  *Subsurface drainage, *Mathematical studies, *Unsteady flow, *Drawdown,
 Groundwater, Seepage, Discharge  (Water), Irrigation, Water balance, Hydrologic bud-
 get, Evapotranspiration.
 Identifiers:  Drain spacing, Transient flow theory.

 The transient-flow theory is used as a basis for determining spacing relationships of
 subsurface drains.  Steady-state flow theory does not adequately describe the chang-
 ing conditions of subsurface drainage.  Research work from Australia and Canada and
 data from a Bureau of Reclamation project were used for checking the validity of the
 mathematical developments of the transient-flow theory under many varying field con-
 ditions.  An actual field problem is given as an example of how field investigational
 data and other available data are used in developing drain-spacing requirements under
 various specified conditions.  Discharge formulas are given and their validity is
 verified by the Australian and Canadian research work.
68-69:02G-024
LEACHING REQUIREMENT FOR EXCHANGEABLE-SODIUM CONTROL,
Rhoades, J. D.
Agricultural Research Service, Riverside, California.
Soil Science Society of America Proceedings, Vol. 32, No. 5, p 652-656, September-
October 1968.  4 fig, 2 tab, 16 ref.

Descriptors:  *Irrigation water, *Sodium, *Leaching, *Cation exchange, *Equations,
Drainage water, Water quality. Saline water, Salts, Root zone, Permeability, Adsorp-
tion, Soil water. Salinity, Arid lands, Lime, Salt tolerance.
Identifiers:  *Leaching requirement, Sodium adsorption ratio, Sodium hazard.

Estimation of the leaching fraction required to maintain the SAR (Sodium-Adsorption
Ratio)  in irrigation water at the lower limit of the plant-rooting zone below some
limiting value was described.  Plant tolerances to sodium and soil permeability reg-
ulate the limiting SAR.  Prediction of SAR values for a calcareous soil was accom-
plished by use of a formula equating the leaching requirement for salinity control
from irrigation and soil waters.
                                      44

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68-69 :02G-025
CHARACTERIZATION OF SOIL AERATION DURING SPRINKLER IRRIGATION,
Stegman, E. C., Erickson, A. E., and Kidder, E. K.
North Dakota State University,   Fargo   /  Dept of Agricultural Engineering.
American Society of Agricultural Engineers, Transactions, Vol. 11, No. I,  p 16-20,
January-February 1968.  6 fig, 2 tab, 20 ref.

Descriptors:  *Sprinkler irrigation, *Aeration, *Infiltration, *Saturation, *Rates
of Application, Soil moisture, Soil structure, Irrigation, Irrigation water, Irriga-
tion efficiency, Irrigation practices, Oxygen, Pores.
Identifiers:  *Soil aeration, *Pore space saturation, *Soil oxygen deficiency,  *0xy-
gen diffusion rate, *Soil intake rate, Desorption.

Various investigators have concluded that there are beneficial effects when sprinkler
irrigation systems apply water at rates well below the normal soil intake  rate.  Data
suggest that decreased soil saturation reduces soil oxygen deficiency.  Therefore a
study was undertaken to develop a practical technique of evaluating aeration adaqaacy
of soils during irrigation.  It was first necessary to know the degree of  pore  space
saturation which could be tolerated by a given soil.  This could be realistically
evaluated by combining oxygen diffusion rate measurements with a soil-moisture-reten-
tion test.  Infiltration tests were conducted and it was clearly demonstrated that
the rate of application influenced the degree of profile saturation.  A feasible
application rate existed such that degree of pore space saturation was not exceeded
in the transmission zone of each of the soils tested.
68-69.-02G-026
EFFICIENT WHEAT IRRIGATION WITH LIMITED WATER,
Schneider, A. D., Musick, J. T., and Dusek, D. A.
Southwestern Great Plains Research Center, Bushland, Texas.
Transactions of the ASAE, Vol. 12, No. 1, p 23-26, January 1969.  5 fig, 4 tab, 7 ref.

Descriptors:  *Irrigation efficiency, *Wheat,  *Crop production, *Water utilization,
*Growth stages, Timing, Soil moisture, Irrigation water, Texas, Plant physiology,
Moisture stress, Moisture deficit, Soil-water-plant relationships, Winter, Rates of
application, Moisture availability, Precipitation (Atmospheric).

A study was conducted at Bushland, Texas during three wheat seasons to determine the
combinations of spring irrigations at four selected stages of plant development that
produced the best water-use efficiencies and to determine some effects on yields and
plant development caused by delaying or deleting irrigations.  The study showed that
irrigation timing was critical when less than an optimum amount of water was applied
to winter wheat.  Every number and timing of the four irrigations was used so that
the effect of any combinations of irrigations could be evaluated.  The most critical
period for adequate soil moisture was from booting through early grain filling.  Mod-
erate soil-moisture stress during early spring did not reduce yields appreciably if
soil moisture was adequate during this critical period.
68-69:02G-027
WATER RELEASE AS A SOIL PROPERTY RELATING TO USE OF WATER BY PLANTS,
Richards, Sterling J.
California University, Riverside, Dept of Soil Physics.
American Society of Agricultural Engineers, Transactions, Vol. 11, No. 1, p 74-75,
1968.  4 fig, 5 ref.

Descriptors:  *Moisture availability, Irrigation practices, Retention, Soil aggreg-
ates, Soil classification, Soil horizons, Soil structure, Field capacity, Wilting
point, Tensiometers, Water storage, Moisture tension, Sudangrass, Water-plant rela-
tionships, Soil mechanics.
Identifiers:  *Water-release curves, Resistance block.

The volume fraction of soil water released to growing plants is proposed as a soil
property for comparing soils or evaluating structural changes in a soil.  Water re-
lease is measured as a function of soil suction, utilizing a tensiometer and a resis-
tance block.  A procedure utilizing soil containers and Sudangrass is detailed.  Be-
cause most field situations present various soil horizons and rooting characteristics
of crops soil-water depletion varies with depth, it is recommended that tensiometers
or blocks be used in each recognized soil horizon and separate water release curves
be drawn.  Total irrigation water depth would be the sum of all the horizons.


                                     45

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 Examples of water-release curves are given for three soils with widely varying tex-
 tures.   Two soils,  in spite of wide differences in texture,  had almost identical
 water-release curves.  Treatment of one soil with an aggregating agent,  VAMA,  result-
 ed in a marked increase in water release.   Water release curves appear to  have advan-
 tages over other procedures for evaluating the property of a soil to  store water  for
 plant use.
 68-69:02G-028
 CONTINUOUS MONITORING OF SOIL MOISTURE TENSION PROFILES,
 Bianchi,  W. C.,  and Tovey,  Rhys.
 American  Society of Agricultural  Engineers,  Transactions,  Vol.  11,  No.  3,  p  441-443,
 447,  May-June 1968.  10  fig,  6 ref.

 Descriptors:   *Moisture  tension,  *Monitoring,  *Measurement,  *Tensiometers, *Equipment,
 Irrigation, Tension,  Soil moisture,  Soil  water,  Strain  gages, Lysimeters,  Manometers,
 Instrumentation,  Calibrations, On-site data  collections. Pressure,  Electrical  equip-
 ment.
 Identifiers:   *Soil moisture  tension,  *Pressure  transducers,  transducers, Scanning
 systems.

 Although  conventional gage  or manometer-type tensiometers  cannot  be used  for long-
 term  measurement of changes in soil  moisture tension, pressure  transducers can be
 effectively employed. Minimum-cost  hydraulic  scanning  and electronic scanning sys-
 tems  were studied and soil  moisture  tensions under  irrigated  alfalfa were  measured.
 Multipoint electronic scanning of many individual strain-gage tensiometers yielded
 reliable  field data throughout the growing season.   In  order  to attribute  soil mois-
 ture  tension  changes  directly to  changes  in  evapotranspiration, it  is necessary to
 thermally isolate the measurement system.  Zero  shift of the  transducers  is  the most
 important limitation  of  the pressure transducer  system.  External means of zero cali-
 bration are required, such  as raising  or  creating a  water  table above transducers in
 lysimeters.
 68-69:02G-029
 ANALYSIS OF  INFILTRATION  INTO  DRAINING  POROUS MEDIA,
 Whisler, Frank D., and Watson, Keith  K.
 Agricultural Research Service, Phoenix, Arizona.
 American Society of Civil  Engineers,  Proceedings, Journal of  Irrigation & Drainage
 Division, Vol. 95, No. IR4,  Paper No. 6946, p 481-491, December 1969.  13 fig, 10
 ref, append.

 Descriptors:  *Infiltration, *Drainage, *Groundwater movement, *Soil water movement,
 Flooding, Irrigation, Water  spreading,  Numerical analysis, Saturated flow, Filtra-
 tion, Hysteresis, Wetting, Drying, Recharge, Sands, Mathematical studies.
 Identifiers:  Wetting fronts.

 Numerical analysis was applied to the inundation of a draining sand column.  A method
 was proposed whereby hysteresis could be considered.  For Botany sand, after periods
 of short drainage between  inundations,  infiltration is rapid.  For longer periods of
 drainage, the ensuing infiltration is slower, but the water moves through the media
 with a much steeper front.   The effects of hysteresis are dynamic, depending upon the
 stage of drainage ana the  relationship  used.  Using a strictly wetting curve gives a
 better prediction than a strictly draining curve.
68-69:02G-030
INFILTRATION OF WATER INTO NONUNIFORM SOIL,
Bouwer, Herman.
Agricultural Research Service, Phoenix, Arizona.
American Society of Civil Engineers, Proceedings, Journal of Irrigation & Drainage
Division, Vol. 95, No. IR4, Paper 6937, p 451-462, December 1969.  5 fig, 2 tab, 11
ref, append.

Descriptors:  *Infiltration, *Soil water movement, *Irrigation, *Water spreading,
Percolation, Runoff, Wetting, Hydraulic conductivity, Mathematical studies, Mathema-
tical models.
Identifiers:  Nonuniform soils.
                                     46

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A simplified procedure for calculating infiltration into soil of nonuniform water
content or hydraulic conductivity, or both, is presented.  The procedure is based on
the Green and Ampt model of piston flow.  Input data consist of the difference in
water content before and after wetting, the hydraulic conductivity after wetting, and
the water entry value of the soil.  Techniques for measuring these parameters in the
field are briefly described.  The procedure is applied to calculate infiltration-time
relationships for flood irrigation of a coarse-textured and a fine-textured soil, and
to evaluate the effect of nonuniform inundation time on irrigation efficiency.  The
results show that the usual recommendation of allowing an inundation-time difference
of not more than 25% of the time required for the desired amount of water to infil-
trate into soil can give irrigation efficiencies of 90% or more.  Thus, larger dif-
ferences in inundation time can be allowed in practice, particularly if the hydraulic
conductivity of the soil decreases with depth.
68-69:02G-031
MOVEMENT OF WATER AND SALT THROUGH A CLAY-WATER SYSTEM:  EXPERIMENTAL VERIFICATION OF
ONSAGER RECIPROCAL RELATION,
Letey, J., and Kemper, W. D.
California University, Riverside, Dept of Soil Physics.
Soil Science Society of America Proceedings, Vol. 33, No. 1, p 25-29, January-Febru-
ary 1969.  2 fig. 2 tab, 12 ref.

Descriptors:  *Osmosis, *Saline water systems, *Soil water movement, *0smotic
pressure, Salinity.
Identifiers:  *Onsager relation, Nonequilibrium thermodynamics.

Equations that describe the movement of solution and salt through a soil system in
which there are both hydrostatic and osmotic pressure gradients are presented.
These equations are:  Jv = -L  ?P + LDD VTT ,  J  = L   VP - L  VTT,'and J /C  =  (-L  +

V)p) VP + (~L_ + L  )  VTT where J  is the flux of solution, J  the difference in velo-

city between water and salt, J  is flux of salt, P is pressure, TT is osmotic pres-
sure, C  is the average solute concentration, and L is phenomenological coefficients.

The Onsager reciprocal relation states that L   = L  .  This relation was found to be

valid for a clay-water-salt system.
68-69:02G-032
SOIL WATER TRANSLOCATION IN A HIGH WATER TABLE AREA,
Benz, L. C., Willis, W. 0., Sandoval, F. M. and Mickelson, R. H.
Agricultural Research Service, Mandan, North Dakota.
Water Resources Research, Vol. 4, No. 1, p 95-101, June 1968.  6 fig, 2 tab, 18 ref.

Descriptors:  *Soil water, *Water table, *Soil temperature, *Confined water, *Trans-
location, Soil water movement. Specific yield, Saline soils, Mulching, Soil surfaces,
Thermocline, Winter, Freezing, Soil profiles, Climatic data.
Identifiers:  *Straw.

This paper reports results of a field experiment conducted to evaluate soil water,
water table and soil temperature relationships in an area having a high water tab-'e,
saline soil and artesian water.  Soil surface treatments were straw cover and no
cover—both without cropping.  Soil water content increased during winter, depending
on the surface treatment.  Average water content of the soil profile increased more
than the amount of water theoretically available on the basis of the specific yield
and the corresponding water table drop.  The additional water was apparently obtain-
ed from artesian groundwater.  Changes in soil water content and water table depth
were associated with soil temperature.  As soil temperature decreased during the
winter, the water table receded, and soil water content increased in the surface
horizons by migration of water from the subsoil.
68-69:02G-033
THE ADAPTABILITY OF AN EXACT SOLUTION TO HORIZONTAL INFILTRATION,
Brutsaert, Wilfried.
Cornell University, Ithaca, New York.
Water Resources Research, Vol. 4, No. 4, p 785-789, August 1968.  3 fig, 12 ref,
1 append.



                                     47

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 Descriptors:  *Infiltratior., Porous media, Seepage, Soil, Moisture, Permeability,
 Darcy's law, Capillary conductivity.
 Identifiers:  *Flow equations, Horizontal infiltration.

 A mathematical solution is provided for the concentration-dependent diffusion equa-
 tion.  The equation is shown to be adaptable to the problem of horizontal infiltra-
 tion, a phenomenon of one-dimensional flow in a partly saturated porous medium,  by a
 suitable approximation of algebraic functions describing the moisture content capil-
 lary suction and the moisture content capillary conductivity relationships.  One of
 the theoretical results that compares favorably with published experimental data
 gives the cumulative infiltration as a simple power function.  Specific equations
 are derived and calculations are plotted.
 68-69:02G-034
 A STEADY-STATE METHOD FOR DETERMINING DIFFUSION COEFFICIENTS IN SOIL,
 Tinker, P. 3.
 Oxford University (England), Soil Science Laboratory.
 Journal of Soil Science, Vol. 20, No. 2, p 336-345, September 1969.   4 fig,  1 tab,
 15 ref.

 Descriptors:   *Diffusivity,  *Cations, *Soil chemistry,  Ion transport,  Soil chemical
 properties,  Laboratory tests, Ion exchange, Electrolytes.
 Identifiers:   Soil diffusivity.

 A simple method for determining steady-state diffusion  coefficients  of cations in
 ooil with cation exchange papers as sources and sinks may  be used at a range of
 moisture contents.  It was tested on the inter-diffusion of Ca and Mg  in a Coral Rag
 clay soil.  Sectioning and analysis of the soil after the  steady state was reached
 give a plot  of composition with distance along the cell which was similar to the
 curved Ca-Mg  exchange isotherm,  and indicated that nearly  all the flux was through
 the liquid phase.   Values of the tortuosity factor could therefore be  found.  There
 were indications that bicarbonate ions were formed and  increased the flux in some
 experiments.   Transient-state diffusion coefficients were  measured in  the same exper-
 iments,  and  agreed fairly well with the steady-state results.
 68-69:02G-C35
 THE  EFFECT  OF OSMOTIC  PRESSURE GRADIENTS ON WATER MOVEMENT IN  UNSATURATED  SOIL,
 Letey,  J.,  Kemper,  W.  D.,  and Noonan,  L.
 California  University,  Riverside,  Dept of Soil  Physics.
 Soil Science  Society of America Proceedings,  Vol. 33,  No.  1, p 15-18,  January-
 February  1969.   2  fig,  5 tab,  6 ref.

 Descriptors:   *Soil water  movement,  *Unsaturated flow,  *0smotic pressure,  Osmosis,
 Clays,  Salinity, Evaporation,  Percolation,  Diffusion,  Flow measurement,  Fluid mech-
 anics,  Permeability.
 Identifiers:   Concentration  gradients.

 Water movement,  in  response  to osmotic  pressure gradients,  was measured  in clay  loam
 and  sandy loam soils at soil water suctions from 0.08  to 15 bars.  Movement  in res-
 ponse to osmotic pressure  gradients were compared to movement  in response  to hydrau-
 lic  pressure  gradients  in  the  soil water suction range  from 0.08 to  0.65 bars.   At
 suction less  than  0.5 bars,  the amount  of water moved by osmotic pressure  gradients
was  generally less  than 4% of  the  water moved by hydraulic  gradients of  equal magni-
 tude.
68-69:02G-036
THE PERMEABILITY OF A POROUS MEDIUM DETERMINED  FP.CM CERTAIN PROBABILITY LAWS FOR PORE
SIZE DISTRIBUTION,
Brutsaert, Wilfried.
Cornell University, Ithaca, New York,  School of Civil Engineering.
Water Resources Research, Vol. 4, Mo.  2, p  425-454, April 1963.   3  fig, 20 ref.

Descriptors:  *Permeability, *Forous media. *Kathematical models, Soil moisture move-
ment, Hydraulic models. Porosity, Dupuit-Forchheimer theory.
Identifiers:  Series-parallel porosity model, Soil moisture-suction relationship,
Porosity-permeability relationships.


                                      4y

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An equation derived for the permeability of a porous medium based on the general
principles of the series-parallel model contains a double integral which is solved
for several continuous probability laws describing the distribution of the sizes of
the interstices of the porous medium.  The agreement between calculated results and
available experimental data is satisfactory.
68-69:02G-037
PORE SIZE DISTRIBUTIONS AS MEASURED BY THE MERCURY INTRUSION METHOD ANT THEIR USE IN
PREDICTING PERMEABILITY,
Klock, G. 0., Boersma, L., and DeBacker, L. W.
Oregon Agricultural Experiment Station, Corvallis.
Soil Science Society of America Proceedings, Vol. 33, No. 1, p 12-15, January-Febru-
ary 1969.  5 fig, 2 tab,  8 ref.

Descriptors:  *Permeability, *Porous media, *Porosity, Equations, Regression analysis,
Soil water movement, Permeameters, Capillary action, Saturated flow, Unsaturated flow.
Identifiers:  Mercury intrusion porosimeter, Pore size distribution, Miilington aid
Quirk equation.

Equations for predicting  the permeability of porous media using pore size distribu-
tion are reviewed and a mercury intrusion method for obtaining pore size distribution
information from samples  is described.  Calculated and measured permeability values
of 35 glass bead and 28 sand samples were compared and agree closely.  Permeabilities
and pore size distributions of 54 systematically selected particle size classes of
glass beads and sand were measured.  Limits of the particle size classes ranged from
44-53 to 208-246 microns  for the particle diameters.  Miilington and Quirk's equation
was used to calculate the permeabilities.  The calculated permeabilities agree with
the measured values only when a correction factor is used.
68-69:020-038
INDEPENDENT MEASUREMENT OF MATRIC AND OSMOTIC POTENTIAL OF SOIL WATER,
Oster, J. D., Rawlins, S. L., and Ingvalson, R. D.
Agricultural Research Service, Riverside, California.
Soil Science Society of America Proceedings, Vol. 33, No. 2, p 188-192, March-April
1969.  3 fig, 15 ref.

Descriptors:  *0smotic pressure, *Water chemistry, *Solutes, Moisture stress, Dens-
ity, Soil water movement, Diffusion, Instrumentation, Tensiometers, Moisture tension.
Identifiers:  Matric potential  (Soil water), Salt exclusion, Psychrometry.

A technique is described that uses the operating principles of the thermocouple psy-
chrometer and the porous plate apparatus to measure the ir.atric and osmotic  potentials
of soil water without extraction of a significant amount of soil solution.   The tech-
nique was tested on a Na-saturated Gila soil to which NaCl solutions with osmotic
potentials of -1, -2, and -6 bars were added.  The standard error of measurement of
the soil water potential components was about 0.04 bar.  The measured osmotic poten-
tials of the soil were lower than those of the added solutions, which can be explain-
ed by salt exclusion although mineral dissolution could contribute to these results.
The technique also permitted measurement of the partial molar volume of soil water
with an accuracy of about 1%.  Within this precision, the partial molar volume of
soil water in this study was shown to be the same as that of pure water.
68-69:02G-039
DISPLACEMENT FRONT UNDER PONDED LEACHING,
Luthin, James N., Fernandez, Pedro, Masloc, Boris, Woerner, Jack, and Robinson,
Frank.
California University, Davis, Dept of Water Science & Civil Engineering.
Journal of the Irrigation & Drainage Division, ASCE,  Vol. 95, No. IR1, Proceedings
Paper No. 6446, p 117-125, iMarch 1969.  4 fig, 7 ref.

Descriptors:  *Leaching, *Saline soils, *Drains, *Ponding, *Salts, Drainage, Irriga-
tion water, Dispersion, Soil chemistry, Soil surfaces, Equa-ions, Theoretical anal-
ysis, Analytical techniques.
Identifiers:  *Displacement, Kirkham's equation.
                                     49

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 Leaching of tile-drained soils by ponding water on the  soil  surface  was  examined both
 experimentally and theoretically.  A method of analyzing movement of the displacement
 front was presented.   The method was based on piston-type displacement of saline soil
 water by the added leaching water.   In this initial analysis presence of precipitated
 salts, hydrostatic dispersion, and soil-chemical reactions were  ignored.   Experimen-
 tal results obtained  on a 15 by 6 by 3 foot tank showed satisfactory agreement  to
 theoretical results obtained by solving Kirkham's equation for the ponded water case.
 Results indicated that ponded leaching was inefficient  in removing salts midway bet-
 ween drains.   Intermittant leaching by applying excessive amounts of irrigation water
 should be more efficient in controlling soil salinity.
 68-S9:02G-040
 EFFECT  OF  SOIL PROFILES  ON MOVEMENT  OF WATER ON  SUBSURFACE  IRRIGATION,
 Whitney, L.  F.,  Muta,  Kazuki,  and  Pira,  E.  S.
 Massachusetts  University,  Amherst, Dept of  Agricultural  Engineering.
 American Society of Agricultural Engineers,  Transactions, Vol.  12,  No.  1, p  98-99,
 January-February 1969.   7  fig,  1 tab,  6 ref.

 Descriptors:   *Subsurface  irrigation,  *Irrigation  systems,  *Interfaces,  *Soil  text-
 ure,  *Soil profiles, Topsoil,  Subsoil,  Irrigation  design, Soil  water movement, Water
 pressure,  Soil moisture.

 Research was concerned with the reaction of water  movement  when water from a pressur-
 ized  source  reached the  interface  between soils  of different  textures.   The benefi-
 cial effects  of a layered soil  profile  for subsurface  irrigation were demonstrated.
 This  is particularly useful in  subsurface irrigation  of  turf  areas  such  as golf cour-
 ses which are  constructed  to specifications.   In irrigation or  crops, however, the
 pipe  network must be placed below  tillage level.   If  the nozzles  lie below the inter-
 face, it is  unlikely that  irrigation water  will  reach shallow-rooted crops.  If the
 nozzles are  above the  interface, i.e.,  the  top 16  inches of soil  is homogeneous, then
 subsurface irrigation  can  be effectively employed.
 68-69 :02G-041
 HEXADECANOL  IN  SOIL -  ITS LOCATIONAL  STABILITY AND  INFLUENCE ON MODULUS OF RUPTURE,
 Myhrman, Matts  A., and Evans, D. D.
 Arizona Agricultural Experiment Station, Tucson.
 Soil Science Society of America Proceedings, Vol. 33, No. 2, p 203-205, March-April
 1969.  2 tab, 9 ref.

 Descriptors:  *Soil structure, *Soil  amendments, *Hexadecanol, *Soil water movement,
 Soil aggregates, Soil  texture, Soil treatment, Soil chemical properties. Soil physi-
 cal properties, Permeability, Soil management, Soil strength.
 Identifiers:  Hexadecanol in  soil.

 Modulus of rupture was reduced 65% for a sandy loam soil and 57% for a silt loam soil
 by addition of  0.4% (by weight) dry powdered hexadecanol.  Emulsified hexadecanol,
 powdered commercial tallow alcohol, and smaller dosages had less effect.  Less than
 2% of the C-14  tagged  hexadecanol placed in a 1-cm thick layer of sandy soil moved
 under either saturated or unsaturated flow conditions.  Movement probably took place
 in the form of  small buoyant  particles.
68-69:02G-042
SOIL MOISTURE AVAILABILITY FOR TRANSPIRATION,
Molz, F. J., Remson, Irwin, and Fungaroli, A. A.
Drexel Institute of Technology, Philadelphia, Pa.
Water Resources Research, Vol. 4, No. 6, p 1161-1169, December 1968.  4 fig, 1 tab,
16 ref.

Descriptors:  *Soil water movement, *Evapotranspiration, Mathematical models, Diffu-
sion, Unsaturated flow, Root zone, Soil moisture.

A differential equation is presented describing radial flow of soil moisture to a
single vertical sink, for instance a root, in an infinite soil mass which is initial-
ly at a uniform moisture content.  The relationship between moisture content and dif-
fusivity for the soils studied may be represented by an exponential function.  A num-
erical solution of the differential equation is used to determine the soil-moisture


                                      50

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 flux.  The results  show  that  for specific soils the decrease in soil moisture with
 time occurs mainly  in  the  immediate vicinity of the sink.  Moisture flux increases
 with initial moisture  content but is essentially time independent.  In natural sys-
 tems the  flux would probably decrease with time because of multiple root interfer-
 ence.  At large  soil-moisture contents, actual transpiration is limited by and equiv-
 alent  to  potential  transpiration.  At small soil-moisture contents, actual transpira-
 tion is limited  by  and equivalent to potential soil-moisture availability.
 68-69:02G-043
 SEEPAGE FROM CHANNELS THROUGH LAYERED POROUS MEDIUMS,
 Jeppson, Roland W.
 Utah State University, Logan.
 Water Resources Research, Vol. 4, No. 2, p 435-445, April 1968.  7 fig, 5 ref.

 Descriptors:  * Seepage, *Channels, *Porous media, *Anisotropy, Mathematical models,
 Groundwater movement. Soil water movement, Surface-groundwater relationships, Approx-
 imation method, Digital computers.
 Identifiers:  Finite difference methods, Layered porous mediums.

 Solutions to steady-state free surface problems of seepage from channels through por-
 ous mediums consisting of layers of different permeabilities are obtained by using
 the methods of finite differences.  In the formulation of the problem, the magnitudes
 of the coordinates x and y are considered the dependent variables, and the potential
 function and the  stream function are considered the independent variables.  The meth-
 od permits the shape of the interface that separates the two layers with different
 permeabilities to be specified.  In the event that each layer is anisotropic, but
 with different ratios of horizontal to vertical permeabilities, the interface between
 the two layers is restricted to being horizontal.  Example solutions are given for
 arbitrarily specified interfaces for both the case of seepage from a trapezoidal
 channel through homogeneous isotropic mediums in each layer  (but of different permea-
 bilities) and the case of anisotropic mediums in which the ratio of horizontal to
 vertical permeabilities is different for each layer.
68-69:02G-044
FIELD MEASUREMENT AND USE OF SOIL-WATER PROPERTIES,
Davidson, J. M., Stone, L. R., Nielson, D. R.,  and LaRue, M. E.
Oklahoma State University, Stillwater, Dept of Agronomy.
Paper No. H-43, presented at 50th Annual Meeting of American Geophysical Union,
Washington, D.C., April 21-25, 1969.  33 p, 16 fig, 4 tab, 15 ref.

Descriptors:  *Soil water movement, *Water properties, Soil orofiles, Hydraulic con-
ductivity, Soil texture, Soil types, Drainage effaces. Drainage, Hysteresis, Darcy's
law.
Identifiers:  *Field measurement, Silty clay, Loamy sand.

Three soil profiles were used for measuring the relationships between the hydraulic
conductivity and soil-water content.  The physical properties of soils varied from
homogeneous to heterogeneous and the surface texture ranged from loamy sand to silty
clay.  No measurable hysteresis was shown from the hydraulic conductivity values
which were calculated from the drainage data.  The Darcy's equation and other assump-
tions were used to predict the rate at which water drained from each soil profile.
68-69:02G-045
A SOLUTION FOR VERTICAL INFILTRATION INTO A DRY POROUS MEDIUM,
Brutsaert, Wilfried.
Cornell University, Ithaca, New York.
Water Resources Research, Vol. 4, No. 5, p 1031-1038, October 1968.  4 fig, 1 tab,
9 ref.

Descriptors:  *Infiltration, *Unsaturated flow, *Porous media, *Mathematical studies,
Soil moisture, Hydraulic conductivity, Diffusivity, Diffusion, Capillary conductiv-
ity, Darcy's law.
Identifiers:  *Vertical infiltration.
                                     51

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 An exact solution  is  presented for the second  term of  the  series  expansion of  the
 numerical solution of the concentration-dependent  diffusivity  equation  of  J. R.
 Philip,   The use of simple algebraic functions describing  the  water  content-capillary
 suction  and  water  content-capillary conductivity relationships of porous media makes
 the exact solution possible.   Terms higher  than second order are  negligible because
 of fast  convergence.   Use of  a previous solution for the first term  of  the exoansion
 together with this solution for the second  term is a satisfactory method of calculat-
 ing vertical infiltration.  The method was  found to be in  good agreement with  results
 of infiltration experiments on Columbia silt loam.
 68-69:02G-046
 STEADY GRAVITATIONAL CONVECTION  INDUCED  BY A  LINE  SOURCE  OF  SALT  IN A  SOIL,
 Raats, P. A. C.
 Agricultural Research  Service, Madison,  Wisconsin.
 Soil  Science Society of  America  Proceedings,  Vol.  33, No.  4,  D  483-487, July-August
 1969.  5  fig,  11  ref.

 Descriptors:   *Convoction,  *Diffusion, *Aqueous  solutions, *Salts, Solutes,  Saturated
 flow, Unsaturated  t ,ow.  Soil water  movement,  Groundwater  movement, Mass transfer,  Ion
 transport, Hydraulic conductivity,  Soil  texture.
 Identifiers:   Salt solution convection.

 A  theoretical  analysis of  steady gravitational convection from  a  line  source of  salt
 in a  saturated or  in a uniformly partially saturated  soil is  presented.  The flow
 pattern of the water-solute mixture and  the distribution  of  the salt are shown to
 depend upon the source strength  of  the line source, the effective mass diffusion co-
 efficient of the  salt  in the soil,  the hydraulic conductivity of  the soil, and a para-
 meter describing  the increase  in density due  to  the added solute.  Qualitatively,  the
 analysis agrees with experimental observations.  Theory and  experiment both  indicate
 that  gravitational convection  can be significant only if  the  hydraulic conductivity
 is large., which may be the  case  if  the soil is coarse textured  and the water content
 is no*- too small.
 68-69:02G-047
 PLANNING AND INTERPRETING  SOIL PERMEABILITY MEASUREMENTS,
 Bouwer, Herman.
 Agricultural Research Service, Phoenix, Arizona.
 American Society of Civil  Engineers, Proceedings, Journal of  the  Irrigation & Drain-
 age Division, Vol. 95, No.  IR3, Paper No.  6775, p 391-402, September 1969.  4 fig,
 3 tab, 19 ref, append.

 Descriptors:  *Perrr,eability,  *3oi] water movement, ^Measurement,  *Planning, Instru-
 mentation, Drainage engineering,  Infiltration, Hydraulic conductivity, Irrigation
 design.
 Identifiers:  Soil permeability measurement.

 Field techniques for measuring soil hydraulic conductivity  (below the water table as
 well as above, or ir. the absence  of, a water table) are considered.  In selecting a
 technique for a given situation,  care should be taken that the soil region and domin-
 ant flow direction in the  system  to be analyzed or predicted  are  as closely duplica-
 ted by the technique as possible.  If the  soil region covered by  an individual meas-
 urement is small compared  to  that of the actual system, measurements at different
 depths and locations are necessary.  The resulting values will seldom if ever be uni-
 form and simplification to  manageable media may be required.  The average hydraulic
 conductivity of a randomly  heterogeneous medium must lie between  the harmonic and the
 arithmetic mean.  Studies with a  resistance network analog show that this avarage
 hydraulic conductivity is best estimated by the geometric mean.
68-69:02G-048
EFFECTS OF PETROLEUM MULCH ON SOIL WATER CONTENT AND SOIL TEMPERATURE,
Kowsar, Ahang, Boersma, L., and uarman, G. D.
Oregon State University, Corvallis, Dept of Soils.
Soil Science Society of America Proceedings, Vol. 33, No. 5, p 783-786, September-
October 19P9.  6 fig, 1 tab, 14 ref.

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 Descriptors:   *Soil management,  *Mulching, *Soil moisture, *Soil temperature, Evapo-
 ration  control,  Soil  conservation, Infrared radiation, Soil physical properties.
 Water loss.  Storage capacity.  Soil water movement.
 Identifiers:   Petroleum mulch.

 Soil temperature and  soil water  content were measured at  2-hour intervals in mulched
 and unmulched  chehalis silty clay loam subjected to a diurnal temperature cycle.  At
 the time  the soil  temperatures attained their maximum value at a depth of 1 cm, the
 mulch-covered  soil was 5C warmer than the bare soil; at all other times the differ-
 ence in temperature between bare and mulched soil was smaller.  In the upper 1 cm of
 mulched soil,  water was lost but the soil gained water at depths where seedlings are
 normally  placed.   It  was concluded that the petroleum mulch improved soil water and
 soil temperature conditions.
 68-69:020-049
 COMPUTATION OF THE DESALINIZATION OF SALINE SOILS UNDERLAIN BY A WATER-PERMEABLE
 LAYER,
 Savel'yeva, R. V., and Baron, V. A.
 Soviet Hydrology:  Selected Papers, Issue No. 1, p 94-98, 1969.  1 fig, 7 ref.
 Translated from  Izvestiya Akad nauk Uzb SSR, ser. tekh nauk No. 3, p 39-43, 1969.

 Descriptors:  *Saline soils, *Leaching, *Land management, Diffusion, Ion transport,
 Mass transfer, Groundwater movement, Soil water movement. Permeability, Heat trans-
 fer, Convection, Salinity, Water quality, Soil chemical properties.
 Identifiers:  *Soil desalination, USSR.

 The salt regime  of soil water forms under the effect of molecular ditfusion, sorption,
 filtration, and  thermal and pressure diffusion.  The gradients of thermal and pres-
 sure diffusion are 4-5 orders of magnitude lower than the gradients of the concentra-
 tion of matter.  Knowing the initial salinization profile, the leaching rate  (magni-
 tude of filtration flow), porosity, the coefficient of convective diffusion, the
 thickness of the fine-earth mantle, and salt concentration of the leaching water,
 the salt regime  of soils may be calculated.
68-69:020-050
LABORATORY METHOD FOR SUPPLYING MOISTURE UNIFORMLY TO SOIL BY CONDENSATION,
Trent, D. S., Larson, M. B., Shen, C. Y., Postlewaite, J. E., and Wolfe, J. W.
Battelle Memorial Institute, Richland, Washington.
American Society of Agricultural Engineers, Transactions, Vol. 11, No. 4, p 519-522,
July-August 1968.  6 fig, 5 ref.

Descriptors:  *Soil moisture, Condensation, *Air circulation, *Thermal conductivity,
*Temperature control, Temperature, Flow rates, Irrigation, Plant physiology, Equa-
tions, Instrumentation.

The three experimental objectives were:  (1) to determine if it were theoretically
possible to uniformly condense moisture in a cooled soil test bed from the flow of
water-saturated air, (2) to discover a practical means of controlling such moisture
deposition, and  (3) to decide if the technique were a suitable instrument to aid lab-
oratory research in plant physiology.  Theory demonstrates that it is probably impos-
sible, and certainly impractical, to obtain perfect moisture uniformity.  However,
the greatest uniformity can be achieved by minimum variation in temperature.  To con-
trol this temperature distribution, pins made from material having a higher thermal
conductivity than the porous bed are placed in the bed parallel to the flow.  The
pins, attached to a cooling plate, appear to increase significantly the effective
conductivity of the bed.  The experiment indicates that optimum uniform moisture de-
position is achieved by adjusting the flow rate until the midpoint temperature is
within the theoretically allowed variation.
68-69:02G-051
WATER MOVEMENT IN DRY SOILS I. PHYSICAL FACTORS AFFECTING SORPTION OF WATER BY DRY
SOIL,
Rose, D. A.
Rothamsted Experimental Station, Harpenden, Herts, England.
Journal of Soil Science, Vol. 19, No. 1, p 81-93, March 1968.  9 fig, 4 tab.
                                     53

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 Descriptors:   *Soil  water movement,  Soil  moisture,  Arid  lands,  Atmosphere, Diffusiv
 ity,  *Temperature,  Salinity,  Evaporation  control, Environmental effects,  *Sorption,
 Water vapor,  Water  transfer,  Equations, Soil  aggregates,  *Moisture  content,  *Soil
 physics.

 The  paper  considered effects  of  various soil  physical  conditions on uptake of water
 from a moist  atmosphere by a  soil  sufficiently  dry  that  both  liquid and vapor compon-
 ents  of  flow  may  be  important.   Water extraction by growing plants  will dry  soil in
 the  root zone to  c pF 4.2 and natural evaporation can  dry surface layers  to  c pF 6 or
 even  drier in arid regions.   Theoretical  aspects of water movement  in dry soils were
 explained  using 5 equations.   Sorption took place in soil columns that were  in a tur-
 bulent atmosphere at constant temperature and relative humidity. Diffusivity rose to
 a  maximum  and then fell as water content  increased.  Effects  of environment  and man-
 agement were  studied in the areas  of temperature, pressure, porosity, organic manure,
 aggregate  size, still atmosphere,  mulching, salinity,  evaporation suppressants, igni-
 tion  and degradation of structure.   In the dry  soils tested,  water  movement  was a
 mixture of liquid and vapor transfer and  the  relative  importance of the two  modes of
 flow  varied from  soil to soil.   The  data  showed the  effect of pre-treatment  on diff-
 usivity and sorptivity,  but there  was no  experience  yet  to indicate what  changes
 might have agricultural significance.
 68-69:02G-052
 CONDUCTIVITY INSTRUMENTATION FOR  IN  SITU MEASUREMENT OF SOIL SALINITY,
 Enfield, C. G., and Evans, D. D.
 Burr-Brown Research Corp., Tucson, Arizona.
 Soil Science Society of America Proceedings, Vol.  33, No.  5, p  787-789, September-
 October 1969.  8 fig, 1 tab, 5 ref.

 Descriptors:  *Electrical conductance,  *Instrumentation, *Salinity, *Soil chemical
 properties, Soil physical properties.  Soil temperature, Aqueous solutions.
 Identifiers:  Soil salinity meters.

 A transducer has been developed which  is capable of assessing,  in situ, the electri-
 cal conductivity of soil water.   The transducer is constructed of porous glass with
 platinum electrodes and operates  over  the entire field moisture range.  The trans-
 ducer is accurate to within 10% when measured with an associated solid state meter
 in a conductivity range of 1-20 millimhos/cm at 25C and a  temperature range of 5-45C.
 Typically, the time required to achieve 63% of equilibrium response, in aqueous solu-
 tions, is less than 2 hours.
68-69:02G-053
QUICK-RETURN SUBSURFACE FLOW,
Jamieson, D. G., and Amerman, C. R.
USDA Hydrograph Laboratory, Beltsville, Maryland.
Journal of Hydrology, Vol. 8, No. 2, p 122-136, June 1969.  1 tab, 16 ref.

Descriptors:  *Soil water movement, *Subsurface runoff, *Routing, *Surface-ground-
water relationships, Water storage, Model studies, Mathematical models, Simulation
analysis, Hydrograph analysis. Systems analysis, Infiltration, Overland flow. Per-
colation .
Identifiers:  Quick-return subsurface flow.

One of the least understood of all hydrologic problems is that of lateral flow in the
soil's upper horizons.  The nature and quantity involved in this quick-return flow
are unknown and have to be inferred from the shape of the observed hydrograph.  An
attempt has been made to mathematically simulate the flow phenomenon using rainfall
as input and a system of interconnected, nonlinear reservoirs as the operator.
                                     54

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 68-69:020-054
 ACTIVATION ANALYSIS: A NEW TECHNIQUE FOR SOIL MOVEMENT STUDIES,
 Beer, Craig E., and Hendrickson, R. A.
 Iowa State University, Ames.
 Agricultural Engineering, Vol. 50, No. 3, p 144-145, March 1969.  1 fig.

 Descriptors:  Soils, *Radioisotopes, *Tracers, *Sediment transport, * Isotopes, Move-
 ment, Gamma rays, Irradiation, *Sediment distribution, Laboratory tests, Hydrologic
 cycle, Hydrology.
 Identifiers:  *Activation analysis, *Lanthanum.

 Laboratory test results show that lanthanum used as a tracer element in activation
 analysis permits detailed study of elements within a hydrologic cycle.   In activation
 analysis, certain elements are irradiated with nuclear particles to produce radioiso-
 topes.  By counting the rate of disintegration of these radioisotopes,  a quantitative
 evaluation of the amount of the original element present is possible.  A soil-lanth-
 anum test sample mixture was irradiated with thermal neutrons.   Analysis showed that
 over 90% of the lanthanum adhered to the soil.  The ultimate objective is to use
 lanthanum as a tracer element in activation analysis to study the origin and movement
 of sediments in certain phases of the hydrologic cycle. The procedure will involve
 mixing lanthanum in soil on a larger scale to produce a seeding batch.   The treated
 soil will then be placed in the field at predetermined points.   Sampling will be done
 immediately after seeding and at points along the flow path.  The apparent ability of
 lanthanum to adhere to inert particles can make its use virtually unlimited.
68-69 :02G-055
MISCIBLE DISPLACEMENT IN AN UNSATURATED GLASS BEAD MEDIUM,
Krupp, H. K., and Elrick, D. E.
Guelph University, Ontario  (Canada).
Water Resources Research, Vol. 4, No. 4, p 809-815, August 1968.  '6 fig, 1 tab,
12 ref.

Descriptors:  *Porous media, *Soil water movement, *Mixing, Water structure, Pore
pressure, Model studies, Tracers.
Identifiers:  *Miscible displacement, *Chemical transport, Unsaturated medium, Pore
volumes.

In order to analyze the mixing behavior of solutes in a porous medium over a wide
range of water contents, a series of miscible displacement experiments was conducted
in an unsaturated glass bead medium, at constant average water content during each
displacement.  Variation in the form of the breakthrough curve with decreasing water
content was not large and was not related in a simple way to the water content; how-
ever, there was a consistent shift of the breakthrough curve to the left of the
relative concentration value of 0.5 and 1 pore volume and a long tail or slow appro-
ach to the final relative concentration of 1.0.  Some of these effects may be attrib-
uted to the presence of  'stagnant' liquid in the pores.  Tbe earliest appearance of
tracer in the effluent was observed at a saturation fraction in the range of 0.54 to
0.56.  This behavior is largely the result of disorder in the sample liquid.  Both
filled and partially filled pores and pore sequences were present in different amou-
nts and mixing was not simply related to moisture content.  At the higher water con-
tents, flow in filled pores was dominant, whereas at lower water contents flow in
partially filled pores and surface films dominated the displacement.
68-69:02G-056
THEORY AND EXPERIMENT IN CANAL SEEPAGE ESTIMATION USING RADIOISOTOPES,
Krishnamurthy, K., and Rao, S. M.
Bhabha Atomic Research Center, Bombay  (India).
Journal of Hydrology, Vol. 9, No. 3, p 277-293, November 1969.  6 fig, 2 tab, 14 ref.

Descriptors:  *Canal seepage, *Radioactivity techniques, *Tracers, *Tracking tech-
niques, *Reviews, On-site investigations, Seepage, Soil water movement, Groundwater
movement, Mathematical studies, Mathematical models.
Identifiers:  *India, Ganga Canal.

A brief survey of the many existing computational and experimental methods in esti-
mating seepage losses from unlined canals is given.  A new method is suggested in
which the filtration velocity of seepage is measured using radioisotopes.  The
                                     55

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 seepage  rate  is  then  computed  from the  knowledge  of  the phreatic curve and Numerov's
 theoretical formula for  laterally spreading  seepages  from  unlined canals.  A prac-
 tical  application  of  the procedure to estimate  seepage losses  from Ganga Canal near
 Roorkee,  India is  also described.
 68-69:020-057
 STEADY-STATE POTENTIAL  AND  MOISTURE-PROFILES  IN LAYERED POROUS MEDIA,
 Poulovassilis, A.
 Athens  School of Agriculture, Athens  (Greece), Dept of Agricultural Chemistry.
 Soil  Science, Vol.  107,  No.  1,  p  47-52,  January 1969.  12  fig, 10 ref.

 Descriptors:  *Soil moisture, *Porous  media,  *Moisture tension, Potential flow.
 Identifiers:  *Moisture  profiles,*Layered  soil.

 The shape of the steady-state potential  and moisture profiles in a layered porous
 column  has been examined both theoretically and experimentally.  It has been shown
 that  the general shape  of such  a  profile depends upon the  layer sequence and the
 suction value prevailing at  the junction which depends not only upon the magnitude
 of the  flow rate*  but  also  for the first  junction upon its position with respect
 to the  water table and  for  the  subsequent  ones upon the width of the layers.
 68-69:02G-058
 PERMEABILITY OF ORTHOTROPIC POROUS MEDIUMS,
 Szabo, B. A.
 New York State University, Buffalo.
 Water Resources Research, Vol. 4, No. 4, p 801-808, August 1968.  4 fig, 1 tab,
 13 ref.
 (see 68-69:02F-046)
68-69:02G-059
INFILTRATION AS INFLUENCED BY TILLAGE-INDUCED RANDOM ROUGHNESS AND PORE SPACE,
Burwell, R. E., and Larson, W. E.
Agricultural Research Service, Morris, Minnesota.
Soil Science Society of America Proceedings, Vol. 33, No. 3, p 449-452, May-June 1969.
3 fig, 3 tab, 9 ref.

Descriptors:  *Infiltration, *Rainfall-runoff relationships, *Soil erosion, Cultiva-
tion, Soil texture, Runoff, Soil physical properties. Permeability, Porosity, Soil
conservation, Soil mechanics, Soil stabilization, Surface runoff, Erosion control.
Identifiers:  Erosion index, Random roughness.

During simulated rainfall, increases in tillage-induced random roughness and pores
space increased water infiltration before runoff started but did not significantly
influence infiltration throughout a 5-cm runoff period.  Random roughness provided a
greater accounting of infiltration variation among tillage treatments to initial
runoff than did total pore volume of the tilled layer.  Freshly turnplowed alfalfa-
bromegrass sod on Barnes loam and Nicollet sandy clay loam soil provided random
roughness and pore space conditions that could accommodate without 'failure' the
major portion of rainfall energy  (as evidenced by El) expected in west central and
southwestern Minnesota during the first 2 months following row crop planting.  This
is the critical runoff-erosion period in the Corn Belt.
68-69:02G-060
SOIL-WATER MOVEMENT IN RESPONSE TO IMPOSED TEMPERATURE GRADIENTS,
Cassel, D. K., Nielsen, D. R., and Biggar, J. W.
California University, Davis, Dept of Water Science and Engineering.
Soil Science Society of America Proceedings, Vol. 33, No. 4, p 493-500, July-August
1969.  10 fig, 4 tab, 21 ref, 1 append.

Descriptors:  *Soil water movement, *Convection, *Water temperature, *Thermodynamic
behavior, *Diffusion, Mass transfer, Diffusivity, Water vapor, Thermodynamics,
Unsaturated flow.
Identifiers:  Temperature gradient, Ficks law.
                                      56

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Redistribution of soil water within insulated, uniformly packed, horizontal samples
of unsaturated Columbia fine sandy loam at several soil-water contents was studied
in response to imposed temperature gradients ranging from 0.5 to l.OC/cm.  Soil bulk
density and initial, transient, and final soil-water-content distributions were det-
ermined each 0.5-cm along the column by gamma-radiation attenuation.  Initial, trans-
ient, and final soil temperature distributions were monitored by glass-encased ther-
mistors at 2-cm intervals-both at the center and 0.3 cm from the column wall.  Appar-
ent thermal and isothermal soil-water diffusivity values were calculated using trans-
ient water content data.  The observed net water flux was found to increase with dec-
reasing water content.  For Columbia soil the observed mean net water flux across
1-cm sections of the soil showed acceptable agreement with that predicted by the
theory of Philip and deVries; Pick's law and the modified Taylor-Cary irreversible
thermodynamic equation both underpredicted the observed fluxes.
68-69:02G-061
THE EFFECT OF THE CONCENTRATION AND MOVEMENT OF SOLUTIONS ON THE SWELLING, DISPER-
SION, AND MOVEMENT OF CLAY IN SALINE AND ALKALI SOILS,
Rowell, D. L., Payne, D., and Ahmad, N.
Reading University  (England), Dept of Soil Science.
Journal of Soil Science, Vol. 20, No. 1, p 176-188, March 1969.  6 fig, 14 ref.

Descriptors:  *Expansive soils, *Ion exchange, *Water chemistry, *Alkaline soils,
*Saline soils, Permeability, Hydraulic conductivity, Expansive clays, Impervious
soils, Electrolytes, Montmorillonite, Adsorption, Laboratory tests, Soil mechanics.
Dispersion, Diffusion.
Identifiers:  Swelling clays, Swelling soils.

Changes in permeability of a soil containing montmorillonite, and the swelling of
orientated aggregates of extracted clay have been found and compared with the con-
centrations at which aggregates dispersed in stationary solutions, and the concentra-
tions at which soil suspensions dispersed when shaken.  The results indicate that  (a)
permeability begins to decrease at the same concentrations as the clay begins to
swell, (b) the changes in permeability are directly controlled by the swelling of
clay until clay dispersion and movement begins,  (c) the concentration at which clay
disperses depends on the mechanical stress applied, (d) when small mechanical stres-
ses are applied, the proportion of the clay which swells and disperses depends dir-
ectly on the exchangeable sodium percentage, and (e) large mechanical stresses may
disperse most of the clay even at low exchangeable sodium percentages.
68-69:020-062
AN ANALYSIS OF THE VERTICAL INFILTRATION OF WATER INTO SOIL COLUMNS,
Thames, John L., and Evans, D. D.
Arizona University, Tucson, Dept of Agricultural Chemistry.
Water Resources Research, Vol. 4, No. 4, p 817-828, August 1968.  10 fig, 4 tab,
8 ref.

Descriptors:  *Infiltration, *Soil, *Porous media, *Soil density, Regression analy-
sis, Flow characteristics.
Identifiers:  *Flux equations, Vertical water infiltration.

To investigate the behavior of soil water movement during infiltration and thereby
determine the applicability of flux equations involving soil water content gradients
as the apparent driving force, an experimental study was made of vertical infiltra-
tion of water.  Sandy loam and silt loam soil materials were used as experimental
media.  Water was allowed to enter air-dry columns of soil at a small constant suc-
tion, and the subsequent distribution was followed with a gamma radiation attenua-
tion device.  An analytical expression of water content as a function of depth and
time was obtained by multiple regression analysis, from which it was possible to
determine the instantaneous flux and the water concentration gradient at given water
contents.  Nonlinearity at low water gradient was evidenced for both soils through-
out a wide range of water contents; the magnitude and direction of departure from
linearity were similar for both soils.  A new empirical flow equation was obtained
by modifying the diffusivity equation for unsaturated flow.  Under this modification,
derived by raising the water-content gradient to a power greater than unity, the
parameter analogous to soil-water diffusivity becomes a function of both water con-
tent and water-content gradient.
                                      57

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 63-69:02G-063
 INFILTRATION OF WATER INTO SOILS AS INFLUENCED BY SURFACE SEAL DEVELOPMENT,
 Edwards,  W. M., and Larson, W. E.
 Agricultural Research Service, Coshocton, Ohio.
 Transactions of the American Society of Aaricultural Engineers, Vol.  12,  No.  4,
 p 463-465,  1969.   4 fig,  1 tab, 11 ref.

 Descriptors:  *Infiltration, *Penetration,  Soil surfaces, Unsaturated flow. Hydraulic
 conductivity, *Impact (rainfall), *Raindrops,  Soil water, Numerical analysis,  Model
 studies .
 Identifiers:  Ida silt loam.

 A numerical solution of the water-flow equation for estimating infiltration into a
 homogenous  soil was used  to describe the effect of a developing surface seal  on  infil-
 tration of  water.   Saturated conductivity for  the surface 0.5 cm of six Ida silt
 loams was determined as a function of length of exposure to simulated rainfall and
 used  in the computer solution to describe infiltration into a soil, the surface  of
 which is  exposed  to raindrop impact.  Estimated two-hour infiltration was reduced by
 as much as  50 percent by  surface sealing.  The suction gradient through the surface
 seal  increased with decreasing conductivity of the seal and with increasing conduc-
 tivity of the layer below the seal.  Low conductivities of saturated  surface  seals
 were  partially offset by  strong suction gradients which move water through the sur-
 face  at rates considerably higher than the  saturated conductivities of the seals.
 68-69:02G-064
 MOISTURE  PROFILES  IN  LAYERED  POROUS MATERIALS DURING STEADY-STATE INFILTRATION,
 Bybordi,  M.
 Cambridge University,  Massachusetts,  School  of Agriculture.
 Soil  Science, Vol.  105,  No. 6,  p  379-383..  June 1968.  3  fig,  8  ref.

 Descriptors:  *Infiltration,  *Groundwater  movement,  Soil moisture,  Soil  physical  pro-
 perties,  Hydraulic  conductivity,  *Darcy's  law. Pares,  Porous  media,  Saturated  flow.
 Identifiers:  *Moisture  profiles,  *Layerftd porous  material.

 A knowledge of  the  dependence of  the hydraulic conductivity and of  the pore  water
 suction of a porous material  upon the degree of saturation permits  an application of
 Darcy's law to  the  calculation  of the moisture profile in a variety of situations.
 This  paper investigates  the applicability  of the procedure to the situation  where the
 soil  profile is layered,  the  pore space  geometry which determines the dependence  of
 hydraulic conductivity upon moisture  content being a function of distance  above the
 water table.  Saturated  and unsaturated  hydraulic  conductivities were established for
 sand  of less than  60  mesh and for sand of  44-60 mesh.   Experiments  were  run  in 200 cm
 column with 100 cm  of  coarse  sand under  100  cm of  fine sand to  establish a steady
 state moisture  profile.   Good agreement  was  found  between the theoretical  moisture
 profiles  and the experimental profiles for a range of  flow rates.
68-69:02G-065
AN ESTIMATION OF SORPTIVITY FOR  INFILTRATION  STUDIES FROM MOISTURE MOMENT CONSIDERA-
TIONS ,
Youngs, E. G.
Agricultural Research Council, Cambridge, England, Unit of  Soil  Physics.
Soil Science, Vol. 106, No. 3, p  157-163, September 1963.   4  fig, 1  tab, 9  ref.

Descriptors:  *Infiltration, Ground water movement, *Soil moisture,  *Hydraulic con-
ductivity, Porous media, Moisture content, Moisture tension.
Identifiers:  *Sorptivity, *Philip's equation, *Moment.

Since Philip's infiltration theory is based on more general properties  than the  ini-
tial moisture content of the porous material, sorptivity has  been calculated from a
knowledge of the hydraulic conductivity and suction relationships with  moisture  con-
tent for a given porous material.  The equations for the analysis of water  uptake by
the moment method are developed for the horizontal and vertical  infiltration cases.
Using the Boltzmann transformation '.-. = xt",  the moment of  the horizontal case is
transformed and a theoretical value for sorptivity based on moisture content is  de-
rived.  Theoretical values and experimental values for A were  compared with  satisfac-
tory agreement.  For the vertical infiltration case, the value for the  coefficient B
in the equation i = AV*E" - B:. was estimated by comparing it with  the  infiltration eq-
uation of Green and Ar.ipt.  The v,;,or feels tnst cne Constant A  can be  obtained  US-
          nation for A i:i the li'.-r'..;'.. :.,al ca^e -arid the constant B can be put equal

                                     58

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to  2/3K0.  The theoretical and experimental values for cumulative infiltration show
good agreement for low values of t for the material tested.  However, results for
large t indicate that care is required in choosing the constant B and using Philip's
equation for vertical infiltration studies.  The results of an experimental investi-
gation of the rate of change of the moment of moisture during water uptake by hori-
zontal columns is given.
68-69:020-066
DETERMINING WATER CONTENT OF DIFFERENT SOILS BY THE NEUTRON METHOD,
Luebs, R. E., Brown, M. J., and Laag, A. E.
Agricultural Research Service, Riverside, California.
Soil Science, Vol. 106, No. 3, p 207-212, 1968.  4 fig, 2 tab, 8 ref.

Descriptors:  *Soil water, *Measurements, *Moisture content, Neutron meters.
Identifiers:  Neutron method.

The relationship between count rate obtained with the neutron method and soil water
content below the 30-cm depth differed for several soils.  The maximum difference ob-
served was equivalent to 4.4 percent water by volume or approximately 0.8 surface cm
for a 15-cm depth increment.  Curve slopes were similar for the soils investigated.
Higher count rates were associated with a higher bulk density of the soil.  Soils for
which the counting rate difference was the greatest differed 0.3 g/cc in bulk density.
Counting rates for soils of the same series were closely related to bulk density in
contrast to the lack of a relationship among series.  The most accurate soil water
determinations, by the neutron method, require calibration for the soil in question
including the consideration of bulk density changes in the profile.  A high linear
correlation between count rate and soil water content was obtained for the 0- to 15-
cm layer.  Repeated field determinations of soil water content in the undisturbed 0-
to 15-cm layer can be satisfactorily obtained by calibrating for the particular soil
and carefully controlling depth of measurement.
68-69:02G-067
EVALUATION OF DYES FOR TRACING WATER MOVEMENT IN ACID SOILS,
Corey, J. C.
Savannah River Laboratory, Aiken, South Carolina.
Soil Science, Vol. 106, No. 3, p 182-187, 1968.  3 fig, 3 tab, 9 ref.

Descriptors:  *Acidic soils, *Tracers, Path of Pollutants, Evaluation.
Identifiers:  Erio Floxine 2G  (Acid Red 1), Crimson Gr Hi Cone  (Acid Red 14),
Alphazurine B Cone (Acid Blue 26).

Suitable nonfluorescent dyes for illustrating streamlines in kaolinitic, acid soils
are Erio Flxoine 2G Supra  (Acid Red 1), Crimson Gr Hi Cone  (Acid Red 14), and Alpha-
zurine B Cone (Acid Blue 26).  None of these dyes moved as rapidly as water.  Dyes
with two sulfonic acid groups moved more readily through acid soils than did dyes
with one sulfonic acid group.  Dyes were used to trace divergence of streamlines
around, coarse gravel lenses during unsaturated flow in finely textured soil.
68-69:02G-068
IN SITU DETERMINATION OF PHYSICAL PROPERTIES OF THE SURFACE LAYER OF FIELD SOILS,
De Vries, J.
British Columbia University, Vancouver, Canada, Dept of Soil Science.
Soil Science Society of America Proceedings, Vol. 33, No. 3, p 349-353, May-June 1969.
9 fig, 3 tab, 5 ref.

Descriptors:  *Soil water, Saturated soils, Physical properties, Soil surfaces,
*Gamma rays.
Identifiers:  Random emission, Collimated beam, Water retention curve.

A set of gamma ray attenuation vs. soil water matrie potential data was obtained in
situ by saturating an undisturbed block of soil, and by lowering the water level in
steps and measuring the count rate through the soil and the corresponding water mat-
ric potential at each step.  Relative water contents were calculated from the count
rates by use of a rational calibration equation.  The corresponding matric potential
was measured with a low impedance tensiometer  .  A partial water retention curve was
plotted from these data, from which in turn the air intrusion value and the aeration


                                      59

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 porosity were inferred.  It was shown that collimation is essential  for  measurements
 within the 1-cm thick surface layer,  but it is not required for measurements  within
 the bulk of a layered system.  With a 5-mc cesium-137  source,  a collimated  beam and a
 4-min counting time, the precision was * 0.6% water content due only to  errors  assoc-
 iated with random emission.  There was good agreement  between  a partial  water reten-
 tion curve obtained in situ and the one obtained with  an outflow method  in  the  lab-
 oratory.
 68-69:02G-069
 DEGRADATION OF WATER QUALITY IN IRRIGATION RETURN FLOWS,
 Law,  J.  P., Jr.,  Davidson,  J.  M.,  and Read, L.  W.
 Robert S.  Kerr Water Research  Center, Ada, Oklahoma.
 Oklahoma State University,  Agricultural Experiment Station Bulletin  B-684,  October
 1970.   26  p,  7 fig,  6 tab,  27  ref,  1 append.

 Descriptors:   *Water quality,  *Return flow, *Irrigation water,  *Salinity, Nitrates,
 Nitrogen,  Fertilizers, Border  irrigation,  Furrow irrigation,  Alkalinity,  Sulfates,
 Calcium, Magnesium,  Sodium, Ammonium compounds.
 Identifiers:   Tillman clay  loam,  Hollister clay loam.  Total dissolved  solids.

 Research has  been conducted concerning regional effects of irrigation  return  flows,
 but few  results are  available  for  evaluation of the quality characteristics of  re-
 turn flow from individual field plots.  The locale selected had  been  in cotton produc-
 tion  for 15 years prior to  initiation of the  study during which time uniform  treat-
 ments  of irrigation  water,  pesticides and  fertilizers  had been  applied.   Soil samples
 were  taken at 4 locations in 3 rows to a depth  of 96 inches prior  to the  first  irri-
 gation and then repeated after the  irrigation season to establish  the  salinity  chan-
 ges within the soil  profile.   Samples of the  surface flows in the  field along with
 soil  moisture extract samples  at different depths were taken  throughout the study.
 Data  indicate a 20%  degradation in  water quality in the surface flows  and a five  to
 eight  fold increase  in salinity in  the percolating water.  The  drainage waters  from
 the irrigation area  were sufficiently degraded  to adversely affect both surface and
 groundwater resources in the area.
 68-69:02G-070
 INFILTRATION OF  WATER INTO  SOILS  AS  INFLUENCED  BY  SURFACE  SEAL DEVELOPMENT,
 Edwards,  W. M.,  and  Larson,  W.  E.
 Agricultural Research Service,  Coshocton, Ohio.
 Transactions of  the  American Society of Agricultural Engineers, Vol. 12, No. 4, p 463
 -465,  1969.  4 fig,  I tab,  11 ref.

 Descriptors:   *Infiltration,  *Penetration,  Soil  surfaces,  Unsaturated  flow, Hydraulic
 conductivity,  *Impact (Rainfall),  *Raindrops, Soil water,  Numerical analysis. Model
 studies .
 Identifiers:   Ida silt loam.

 A numerical solution of the  water-flow equation  for estimating infiltration into a
 homogenous soil  was  used to  describe the effect  of a developing surface seal on in-
 filtration of water.   Saturated conductivity  for the surface  0.5 cm of six Ida silt
 loams  was determined as a function of length  of  exposure to simulated  rainfall and
 used in the computer solution to  describe infiltration  into a soil, the surface of
 which  is  exposed to  raindrop  impact.  Estimated  two-hour infiltration  was reduced by
 as much as 50 percent by surface  sealing.   The  suction  gradient through the surface
 seal increased with  decreasing  conductivity of  the seal and with increasing conduc-
 tivity of the  layer  below the seal.  Low conductivities of saturated surface seals
 were partially offset by strong suction gradients which move water through the sur-
 face at rates condiderably higher than the  saturated conductivities of the seals.
68-69:02G-071
EFFECTS OF TILLAGE, NO TILLAGE, AND MULCH ON SOIL WATER AND PLANT GROWTH,
Jones, J. N., Jr., Moody, J. E., Lillard, J. H.
Agricultural Research Service, Blacksburg, Virginia.
Agronomy Journal, Vol. 61, No. 5, p 719-721, September-October, 1969.
7 ref.
(See 68-69:03F-027)
2 fig,  3 tab,
                                      60

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68-69:02G-074
CHROMATOGRAPHIC MODEL FOR PREDICTING  PESTICIDE  MIGRATION IN SOILS,
King, P. H., and McCarty, P. L.
Virginia Polytechnic Institute and Stanford University.
(See 68-69:05A-007)
                                     61

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                                     SECTION VI


                      WATER CYCLE - WATER IN PLANTS (Group 021)


68-69:02I-001
EVALUATION OF COTTON RESPONSE TO RATES, SOURCES, AND TIMING OF NITROGEN APPLICATION
BY PETIOLE ANALYSIS,
Amer, F., and Abuamin, H.
University of Alexandria, United Arab Republic, Dept of Soils.
Agronomy Journal, Vol. 61, No. 4, p 635-637, July-August 1969.  1 fig, 1 tab, 12 ref.

Descriptors:  *Ammonium compound. Calcium, Nitrogen, Cotton.
Identifiers:  Availability coefficient.

Three experiments were conducted on a calcareous clay loam soil to determine the re-
lationship between nitrate-nitrogen content of cotton (Gossypium barbadense) petiole
and yield;  and to employ the petiole analysis technique for evaluation of calcium
nitrate, ammonium nitrate, and urea as N sources and evaluation of timing of N appli-
cation.  Increase in cotton yield associated with unit increment of petiole nitrate
was proportional to the decrement from the maximum and the data were fitted to the
exponential equation of Spillman.  Cotton yield was not affected by N source and
time of application, but petiole nitrate was sensitive to both.  Calcium nitrate was
the best fertilizer and the availability coefficients of N in ammonium nitrate were
0.714 and 0.511, respectively.  Splitting the applied N in thirds proved superior to
a split into two applications or to a single total application, and the availability
coefficients ratios were 20.889, and 0.566, respectively.
68-69:02I-002
GROWTH, YIELD, AND YIELD COMPONENTS OF SAFFLOWER AS AFFECTED BY IRRIGATION REGIMES,
Erie, L. J., and French, 0. F.
U.S. Water Conservation Laboratory, Phoenix, Arizona.
Agronomy Journal, Vol. 61, No. 1, p 111-113, January-February 1969.  1 fig, 5 tab.

Descriptors:  Consumptive use, *Irrigation, Available water, Soil moisture, Seeds.
Identifiers:  *Frio safflower, Yield per unit of water, Irrigation management.

Three to nine irrigations were given in eight irrigation treatments of fall-planted
Frio safflower.  Irrigations were given when 60 or 72% of the available water in the
top 120 cm of soil was depleted.  Five different irrigation cutoff dates were com-
pounded on the soil moisture depletion treatments, ranging from 3 weeks before first
blossoming until harvest.  The yield of safflower seed increased with each increment
of irrigation water to a maximum yield obtained with seven irrigations given until
the last blossoms opened  (3,961 kg/ha).  Consumptive use for this treatment was 107
cm of water.  When the last irrigation was given at the first flowering data, seed
yield was reduced over 800 kg/ha.  Giving the last irrigation about 10 days before
blossoming reduced yields nearly one-half.  Weight per seed, oil content, and seeds
per head also increased with irrigations up to seven, and the percentage of hollow
seed decreased.  The seven-irrigation regime also resulted in the greatest yield per
centimeter of water used by the plant.  The level of moisture depletion before irri-
gation had no significant effect on any of the factors studied.
68-69 :02I-003
NITROGEN CONTENT OF GRAIN AS INFLUENCED BY WATER SUPPLIED TO THE PLANT,
Stone,  J. F., and Tucker, B. B.
Oklahoma State University, Stillwater, Dept of Agronomy.
Agronomy Journal, Vol. 61, No. 1, p 76-78, January-February 1969.  4 fig, 2 tab,
4 ref.

Descriptors:  *Crop production, *Fertilization, Wheat, Sorghum, Irrigation, *Nitro-
gen, *Protein, Plant physiology.
Identifiers:  *Grain quality.

Results of independent studies involving wheat  (Triticum aestivum L.) and grain sor-
ghum (Sorghum bicolor  (L.) Moench) indicate that a linear relationship exists between
nitrogen fraction in the grain and the quantity of water applied to the soil surface
                                     63

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 just prior to  and through vegetative growth  of  the  plant.   The  effect was noted con-
 sistently in studies in Oklahoma and Texas.   The  designated purpose of  these studies
 was  to  determine  effects of fertilizer  amounts  and  irrigation amount and timing on
 the  production of crops.  The  studies were conducted  at widely  separated locations
 over eight growing seasons.  The effect was  noted by  chance during evaluation of one
 of  the  studies and was found to  exist in  data found in the  literature and in data
 from other studies of the authors.
 68-69:021-004
 INFLUENCES  OF  WATER MANAGEMENT  AND  FERTILITY ON RICE GROWTH AND YIELD,
 Oelke,  E. A.,  and Mueller,  K. E.
 California  University,  Davis, Dept  of Agronomy.
 Agronomy Journal, Vol.  61,  No.  2, p 227-230, March-April  1969.  1  fig, 4 tab, 12 ref.

 Descriptors:   *Rice,  *Nitrogen,  *Water management, Plant  populations, Moisture con-
 tent.
 Identifiers:   Dry weight  accumulation. Leaf area.

 Several water  management  systems  for water-seeded rice  (Oryza sativa L.), each with
 several nitrogen levels,  were compared for 3 years as to  their influence on growth
 and yield.  A  shallow (4cm) water depth all season consistently gave higher yields
 than  intermediate  (8cm),  deep  (18cm), or  fluctuating  (4cm and then 18cm) water depths.
 Relative fertility  and  varietal  responses were similar  for all water management sys-
 tems.   Daytime water  temperature, tillers per plant, shoot dry weight, plant popula-
 tion, active leaf area  per  plant, panicles per plant, panicles per square meter,
 total nitrogen in the shoots at  30  days,  and total nitrogen in the grain were greater
 in shallow  water than in  the other  water  management systems.  Seedling emergence and
 flowering were earlier  in shallow water,  but lodging was  greater and total nitrogen
 in the  straw was lower  than in  the  other  systems.  The  greater number of panicles
 per square  meter was  the  yield  component  which contributed most significantly to the
 higher  yields  obtained  with shallow water.
68-69 :02I-005
EFFECT OF IRRIGATION ON RECOVERY OF APPLIED NITROGEN BY COTTON,
Doss, B. D., and Scarsbrook, C. E.
Agricultural Research  Service, Thorsby, Alabama.
Agronomy Journal, Vol. 61, No. 1, p 37-40, January-February 1969.  3 fig, 7 tab,
10 ref.

Descriptors:  *Irrigation, Nitrogen, Cotton, Fertilizer, Root development.
Identifiers:  Dry matter production, Root growth, Soil moisture extraction.

Field studies were conducted on a Greenville fine sandy loam to determine the effects
of soil moisture regime and N rate on recovery of applied N by cotton.  In general,
irrigation decreased the percentage of N in plants but tended to increase total N
uptake as a result of  the increase in dry matter production.  Applied N increased
both the N percentage  and total N uptake of plants, either with or without irrigation.
The slopes of the linear regression equations for nitrogen recovery on nitrogen
applied for irrigated  cotton were about twice as large as those for unirrigated cot-
ton.  Five years' data for both irrigated and unirrigated cotton closely fit the re-
gression equation log  Y = 2.333 + 0.727 log^^where Y = dry matter yield and X = N
uptake.
68-69 :02I-006
MOISTURE CONTENT OF COTTON LEAVES AND PETIOLES AS RELATED TO ENVIRONMENTAL MOISTURE
STRESS,
Longenecker, D. E., and Lyerly, P. J.
Texas A&M University, El Paso, Dept of Agronomy.
Agronomy Journal, Vol. 61, No. 5, p 687-690, September-October, 1969.  3 fig, 16 ref.

Descriptors:  *Cotton, *Moisture content, *Soil moisture, Irrigation, *Moisture
stress, Soil-water-plant relationships.
Identifiers:  *Petioles.
                                      64

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Moisture content of topmost mature cotton (gossypium) leaves and petioles, from
irrigation to permanent wilting, was determined directly in two studies -- one in
the greenhouse and one in the field.  Fresh weight moisture percentages of both
leaves and petioles were shown to decrease gradually as soil moisture was depleted,
dropping more rapidly near permanent wilting.  Petioles showed consistently higher
moisture percentages and more uniform depletion curves than leaves throughout the
moisture extraction periods.  This suggests that cotton petioles may be more reliable
and more useful indicators of the constantly changing plant-soil-moisture relation-
ship than leaves.
68-69:021-007
RESTORING PRODUCTIVITY ON PULLMAN SILTY CLAY LOAM SUBSOIL UNDER LIMITED MOISTURE,
Eck, H. V.
Agricultural Research Service, Bushland, Texas.
Soil Science Society of America Proceedings, Vol. 33, No. 4, p 578-581, July-August
1969.  5 fig, 1 tab, 10 ref.

Descriptors:  *Soil water, *Soil-water-plant relationships, *Nitrogen, Fertilization,
Productivity, Water requirements, *Crop response.
Identifiers:  *Water use efficiency, Topsoil removal and accumulation.

Applied fertilizer restored grain sorghum (Sorghum vulgare) yields on 10-cm cut Pull-
man silty clay loam to 93% of those obtained on uncut soil.  On 20-, 30-, and 41-cm
cuts, yields were restored to 87% of those on uncut soil.  Soil water storage, water
use, and water-use efficiency data revealed that differences in soil water storage
and use were responsible for differences in yield when fertility was not limiting.
Topsoil removal decreased and fill increased water-holding capacity of the soil pro-
file.  Topsoil removal decreased water loss from fallowed soil, but fill had little
effect.  N was the only added nutrient required to produce highest yields obtained
under limited moisture conditions in this study.  Inadequately fertilized treatments
used less water than adequately fertilized ones, but water-use efficiency was greater
where plant nutrients were adequate.
68-69 :02I-008
EFFECT OF MOISTURE REGIMES AND HARVESTS ON EFFICIENCY OF WATER USE BY TEN FORAGE
CROPS,
Powell, R. D., and Kardos, L. T.
The Pennsylvania State University, Agricultural Experiment Station.
Soil Science Society of America Proceedings, Vol. 32, No. 6, p 871-874, November-
December 1968.  6 tab, 10 ref.

Descriptors:  *Legumes, *Crop production, *Irrigation effects, Irrigation efficiency,
Evapotranspiration.
Identifiers:  *Grasses, *Blaney-Criddle values, *Harvest effects.

The total amounts and rates of depletion of soil water required to produce dry matter
by 10 crops were studied.  Two experiments with forages were conducted, one being
managed to simulate pasture and the other being managed for hay.  Three levels of
soil moisture management were used in each experiment:  control  (MQ), irrigation when
the available soil water at the 10 cm depth was 85% depleted  (M]_), and irrigation
when available soil water at the 10 cm depth was 30% depleted  (M2).  On the basis of
total harvest for all the species, most efficient use of water occurred at the Mg
irrigation level.  Also, most efficient use of water occurred prior  to the first
harvest and least efficient use usually occurred during the period after the  first
harvest but 'jric^ to tha second harvest.  Ladino clover and ladino-orchardgrass
'Trifoliu.-, r -. -oens-Diictylis glcnc-rata) harvested to simulate pasture  were less effi-
cient ir. :.&:ng water than the other forages which were managed for hay.  Alfalfa
svaias  (Mec.Lcaco saliva) managed for hay were more efficient than  the other swards
and the legume-grass ccinbinatLO:,t differed only slightly frorr, legumes alone.  Mea-
sured values for rates of moisture depletion per day of all unirrigated forages were
generally s.Toiler ~han values computed by using the Elaney-Criddle formula.  The
measured values of the irrigated forages approached the Blaney-Criddle values more
closelv.
                                     65

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 68-69:021-009
 SOIL WATER SUPPLY AND DEPLETION PATTERN DIFFERENTIATE  AMONG ZEA MAYS  L.  SINGLE- AND
 DOUBLE-CROSS HYBRIDS,
 Bruce,  R.  R. ,  Sanford,  J.  O.,  Grogan,  C.  O.,  and Myhre,  D.  L.
 Agricultural Research Service,  Watkinsville,  Georgia.
 Agronomy Journal, Vol.  61, p 416-421,  May-June  1969.   6  fig,  9  tab, 6 ref.

 Descriptors:  *Irrigation, *Crop response,  *Corn,  *Irrigation effects, Crop produc-
 tion,  *Phenology,Soil water.
 Identifiers:  *Zea mays L.

 The  relationship of irrigation response of  several double-  and  single- cross  Zea
 mays L.  hybrids  to inbred  line composition  and  effectiveness  in supplying  the plant
 water  requirements from the soil water supply was  investigated.  An experiment in-
 volving  25 double-cross hybrids showed that 15  of  these  hybrids gave  a 10% or greate:
 grain  yield response to irrigation,  whereas the remainder showed very little  or no
 yield  increase.   Certain hybrids produced about as well  without irrigation as the
 highest  yielding irrigation-responsive hybrids.  Subsequent experiments  examined the
 irrigation response of  several  single-cross hybrids and  their double-cross products.
 In a season of severe drought  requiring major irrigation, yield response of the
 double-cross products to irrigation  was predicted  very well by  averaging the  yield
 response of the  four non-parental single  crosses of the  four  inbreds  involved.
 68-69:021-010
 NITROGEN ECONOMY OF  CROPPED AND UNCROPPED FLOODED RICE  SOILS UNDER FIELD CONDITIONS,
 Racho, V. V., and De Datta, S. K.
 The  International Rice  Research Institute, Los  Banos, Laguna, Philippines.
 Soil Science, Vol. 105, No. 6, p  419-427, June  1968.  6  fig, 2  tab, 23 ref.

 Descriptors:  *Nitrogen, Fertilization,  *Flood  irrigation, Crop production, Rice,
 Nitrogen cycle.

 Most of the mineral  nitrogen present  in  a flooded Maahas clay was ammonium nitrogen.
 Although the amount  at  transplanting  was closely related to the amount of nitrogen
 fertilizer added, the amount in all treatments  at harvest was similar, suggesting
 that there was no carry-over of fertilizer nitrogen, irrespective of rates of appli-
 cation, for a succeeding rice crop.   Substantial amounts of mineral nitrogen remain-
 ing  in the soil at harvest represent  a reserve  for use by a subsequent crop provided
 the  soil is kept submerged in the  interim.  The data indicate that if adequate fer-
 tilizer nitrogen is  incorporated  before  transplanting,  it should not be necessary on
 this soil to apply further nitrogen at the panicle primordium initiation stage of an
 early maturing, lodging-resistant  rice variety.  Considerable quantities of nitrogen
 were unaccounted for at harvest and the  amount  increased with fertilizer application
 These discrepancies  remain unexplained and indicate the need for further research.
 Plant nitrogen analyses suggested  that rate of  nitrogen fertilizer application did
 not affect the removal  of soil nitrogen by the  rice crop.  Estimated fertilizer rec-
 overy by the plant decreased with  increased fertilizer application.
68-69 = 021-011
FUNCTIONS FOR COTTON  (GOSSYPIUM HIRSUTUM L.) PRODUCTION FROM IRRIGATION AND NITROGEN
FERTILIZATION VARIABLES: II. YIELD COMPONENTS AND QUALITY CHARACTERISTICS,
Grimes, Donald W., Dickens, W. L., and Anderson, W. D.
California University, Davis, Dept of Water Science and Engineering.
Agronomy Journal, Vol. 61, No. 5, p 773-776, September-October 1969.  3 fig, 3 tab,
"If 'f~ fTi •*"

Descriptors:  *Crop response, *Cotton, *Irrigation efficiency, *Plant growth, *Nitro-
gen, Arid lands, California, Soil-water-plant relationships, Statistics, Crop produc-
tion, Fibers  (Plant) .
identifiers:  ^Production function, Plant quality.

Tests were conducted on 2 soils in the arid San Joaquiri Valley of California to de-
velop relationships of applied irrigation water and nitrogen to cotton yield compo-
nents, plant height and fiber quality.  Equations were developed relating plant hei-
ght, flowers, bolls and lint quality to the amount of water applied for 3 levels of
nitrogen.  There was a positive correlation between yield and number of flowers and
bolls.  Plant height continued to increase with additional water, but beyond a cer-
tain ooint lint yield responded negativelv.  Fiber quality was primarily a function
of '.-."tor rather than nitrogen.

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68-69:02I-012
FUNCTIONS FOR COTTON  (GOSSYPIUM HIRSUTUM L.)  PRODUCTION FROM IRRIGATION AND NITROGEN
FERTILIZATION VARIABLES: I.YIELD AND EVAPOTRANSPIRATION,
Grimes, D. W., Yamada, H. , and Dickens, W. L.
California University, Davis, Dept of Water Science and Engineering.
Agronomy Journal, Vol. 61, p 769-773, September-October 1969.  6 fig, 2 tab, 13 ref.

Descriptors:  *Crop production, *Crop response, *Fertilization, *Irrigation, *Cotton,
Nitrogen, Evapotranspiration, Soil moisture.
Identifiers:  *Production function, Second-degree polynomial, Water-use efficiency.

Cotton lint yield, evapotranspiration (ET) , and efficiency of water use were charac-
terized with 2nd-degree polynomials as functions of the quantity of irrigation water
and nitrogen applied on two widely different  soils.  Excessive vegetative plant de-
velepment at high input levels of irrigation water and nitrogen resulted in production
functions for lint yield having negative interaction coefficients.  By placing lint
yield on a relative basis for the two soils,  it was possible to express relative
yields as a function of ET with a single quadratic regression equation (R. Y. = 266.4
+ 10.72 (ET) - 0.079(ET}2; R2 = 0.78).  Total seasonal ET increased at a decreasing
rate with increased water application up to an addition of 119 cm of water during the
entire growing season.  Peak daily rates of soil moisture depletion were 1.07 cm,
occurring near the time when maximum leaf area was attained.  Water use efficiency
(kg lint per cm of water used)  was improved  in some cases with the addition of
nitrogen.
68-69:021-013
EFFECTS OF EXTERNAL SALT CONCENTRATIONS ON WATER RELATIONS IN PLANTS: VI. EFFECTS
OF THE EXTERNAL OSMOTIC WATER POTENTIAL ON SOLUTE REQUIREMENT, SALT TRANSPORT, KINE-
TICS AND GROWTH RATES OF LEAVES,
Oertli, J. J.
California University, Riverside, Dept of Soils and Plant Nutrition.
Soil Science, Vol. 105, No. 5, p 302-310, 1968.  12 fig, 9 ref.

Descriptors:  *Salts, *Soil-water-plant relationships, *Osmotic pressure, *Plant
growth, *Arid lands, Salinity, Plant physiology. Air environment, Soil environment,
Environmental effects, Vegetation effects, Leaves, Moisture stress, Turgidity, Solu-
tes,  Soil water, Cytological studies, Barley, Kinetics, Xylem, Growth rates, Iso-
therms .
Identifiers:  *Water potential, *Salt transport (Plants).

This is one of a series of reports on effects of salt in soil water on plant-water
relations.  The experiment measured osmotic potential in the petiole and external
solution using a Mechrolab vapor pressure osmometer.  Turgor pressure of expanding
leaf cells was arbitrarily set at 5 bars.  The external solute requirement required
to maintain this turgor pressure as water potential varied was measured.  The re-
sults are presented in graphic form.  Different turgor pressures would result in par-
allel shifts in the curve.  Results indicate that solute requirements to maintain
turgor pressure in leaves increase in proportion to external water stress.  Salt
transport through the plant decreases in efficiency with increasing salt accumula-
tions.  In elongating cells solute requirements must be met continuously.  It fol-
lows then that cell expansion and leaf growth should be less at either low or high
salt concentrations.  The optimum level will be somewhere in the middle.  Experimen-
tal results with barley seedlings supported this conclusion.  It was observed that
high atmospheric moisture stress, common in arid lands, decreased growth rates by
increasing solute requirements.  Growth reduction, even without visible leaf injury
caused by salinity, is a result of osmotic relationships.
68-69:021-014
EFFECTS OF EXTERNAL SALT CONCENTRATIONS ON WATER RELATIONS IN PLANTS: IV. THE COM-
PENSATION OF OSMOTIC AND HYDROSTATIC WATER POTENTIAL DIFFERENCES BETWEEN ROOT XYLEM
AND EXTERNAL MEDIUM,
Oertli, J. J., and Richardson, W. F.
California University, Riverside, Dept of Soils and Plant Nutrition
Soil Science, Vol. 105, No. 3, p 177-183, 1968.  7 fig, 10 ref.

Descriptors:  *Salinity, *Osmotic pressure, *Hydrostatic pressure. Circulation  (Pla-
nts), Plant physiology, Transpiration, Moisture uptake, Microenvironment, Soil-water
-plant relationships, Irrigation effects, Root zone, xylem.



                                     67

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 Experiments  on  sunflower  plants  and  tomato  plants  show  that  variations of the osmotic
 potential  difference  between  root xylem  and external medium  are nearly compensated
 for  by variations  of  the  hydrostatic potential  difference, so  that their sum stays
 nearly independent of external-solution  concentrations  having  osmotic potentials of
 0  to -5 bars.   Increasing salt concentrations only altered this relationship slightly
 while reducing  transpiration  rates substantially.  This absence of proportionality
 between transpiration rate change and change in the net osmotic-hydrostatic potential
 differences  is  probably the result of a  solute  accumulation  at the root surface and
 in the root  free space.   Other explanations include change of  root permeability for
 water,  due to the  salinity, or systematic error in experimental procedures.
 68-69:021-015
 EFFECTS OF  EXTERNAL  SALT  CONCENTRATIONS ON WATER RELATIONS  IN PLANTS: V. SIGNIFICANCE
 OF EXTERNAL WATER-POTENTIAL AND  SALT-TRANSPORT KINETICS ON  RATE OF CELL EXPANSION,
 Oertli, J.  J.
 California  University,  Riverside, Dept of Soils and Plant Nutrition.
 Soil Science, Vol. 105, No. 4, p  216-222, 1968.  2 fig, 18  ref.

 Descriptors:  *Salinity,  *Saline  soils, *Soil-water-plant relationships, *Plant phys-
 iology, *Plant growth,  *0smotic  pressure, Turgidity, Xylem, Kinetics, Cytological
 studies.
 Identifiers:  *Turgor pressure,  Salt transport.

 Soil salinity generally results  in a reduction of plant growth.  This report theor-
 etically investigates the effect  of external salt concentration and of the solute
 transport on cell elongation.  When internal hydrostatic pressure exceeds external
 pressures,  plant cells  elongate.  If water transport into the cell occurs in response
 to salt addition to  the vacuole,  the rate-limiting factor is probably the salt, and
 not the water transport.  Solute  requirement is a function  of total water potential
 at the root surface.  Salt transport rates depend upon external concentration and
 obey kinetics of decreasing efficiency.  The cell elongation rate depends upon exter-
 nal concentration; the  time for unit elongation decreases,  passes through a minimum
 and subsequently increases in the range of saline conditions.  Experimental support
 of the conclusions will be presented in a subsequent paper.
68-69:02I-016
ALFALFA WATER TABLE INVESTIGATIONS,
Tovey, Rhys.
Agricultural Research Service, Reno, Nevada.
American Society of Civil Engineers Proceedings, Journal of the Irrigation and Drain_
age Division, Vol. 95, No. IR4, Paper 6974, p 525-535, December 1969.  7 fig, 1 tab,
7 ref.

Descriptors:  *Evapotranspiration, *Consumptive use, *Alfalfa, *Groundwater movement,
*Water level fluctuations, Water table, Irrigation, Irrigation water, Irrigation
efficiency, Water demand, Water utilization, Lysimeters, Soil moisture.
Identifiers:  Water use  (Alfalfa).

Use of water by alfalfa growing under high water table conditions was studied to de-
termine the irrigation requirement.  A thre-e-season average of consumptive use and
yield of alfalfa, disregarding soil textures, showed an almost straight-line relation-
ship with water table depth for the nonirrigated treatment.  The nonirrigated alfalfa
showed the effects of static water table depth on the consumptive use and yield of
alfalfa.  Peak consumptive use occurred when the alfalfa was at or approaching the
one-tenth bloom stage and temperatures were high.  Only minor differences in the
growth of alfalfa were found for the various static water table, soil, and irrigation
treatments.  The alfalfa plants in the lysimeters showed good root development, with
roots in the saturated zone and enlarged white rootlets extending below the water
table level.  Pan evaporation, net radiation, and the Olivier method adequately pre-
dicted cumulative consumptive use for an 8-ft water table, but were low for 2-ft and
4-ft water table depths.  None of the prediction methods reflected peak consumptive
use periods for alfalfa grown in the presence of static shallow water tables.
                                      68

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68-69:021-017
CROP RESPONSES TO RAINFALL MULTIPLIERS,
Wittmuss, H. D., and Ehlers, P. L.
Nebraska University, Lincoln, Agricultural Experiment Station.
American Society of Agricultural Engineers Transactions,  Vol.  11,  No.  4,  p 484-486,
July-August 1968.  1 fig, 4 tab, 7 ref.

Descriptors:  *Water harvesting, *Water utilization, *Crop response,  *Irrigation
efficiency, *Semiarid climates, Great Plains (Nebr), Sorghum,  Wheatgrass,  Crop prod-
uction, Soil-water-plant relationships, Rainfall, Bench leveling,  Slopes,  Water yield
improvement.
Identifiers:  *Rainfall multipliers, *Sealed contributing areas.

In a study of water-use efficiency in a semiarid area of  Nebraska, rainfall multipli-
ers were installed.  They consisted of sealed contributing areas on a  3%  slope above
level bench areas.  The increased available water was used on grain sorghum and in-
termediate wheatgrass plots.  With 100, 150, 200, and 250 percent of  rainfall avail-
ability, the sorghum plots yielded 3.9, 3.6, 3.2, and 2.8 bu per acre-inch of water,
respectively (1963).  The grain yield was highest on the  195 percent  plot.  With
100, 150, 200,  and 250 percent of rainfall availability,  the wheatgrass plots yielded
130, 140, 171,  and 148 Ib of hay per acre-inch of water,  respectively  (1964-1966).
In 1966 irrigated plots of wheatgrass produced 50 percent more hay than any rainfall
multiplier plot during the three-year period.  However, the plots receiving 200 per-
cent rainfall in 1965 produced as much hay per unit of water as the irrigated plots.
Further studies are needed to improve water harvesting and efficient  water utiliza-
tion in semiarid areas such as the Great Plains.
68-69:021-018
MONITORING COTTON PLANT STEM RADIUS AS AN INDICATION OF WATER'STRESS,
Namken, L. N., Bartholic,  J. F., and Runkles, J. R.
Agricultural Research Service, Weslaco, Texas.
Agronomy Journal, Vol. 61, p 891-893, November-December 1969.  3 fig,  4 ref.

Descriptors:  *Cotton, *Soil-water-plant relations.
Identifiers:  Water stress, Transducer, Growth characteristics,  Leaf water potential.

Cotton plant water stress  was monitored continuously during a drying cycle by measur-
ing microchanges in plant  stem radius with a linear variable displacement transducer
(LVDT).  Plant stem contraction was directly related to the degree of  leaf water
stress, and plant stem radius was very responsive to changes in the energy load at
the evaporating surface.  The LVDT provided a stable, trouble-free method for monit-
oring relative plant water stress under field conditions without destroying plant
tissue.
68-69:021-019
EFFECTS OF VERTICALLY HETEROGENEOUS SOIL SALINITY ON PLANT GROWTH AND WATER UPTAKE,
Shalhevet, J., and Bernstein, L.
California University, Riverside.
Soil Science, Vol. 106, No. 2, p 85-93, August 1968.  5 fig, 2 tab.

Descriptors:  *Saline soils, *Alfalfa, *Root systems, Equations, Growth chambers,
*Crop response, Osmosis, Salt tolerance, Irrigation effects, *Moisture uptake, fbsorp-
tion, On-site data collections, Soil-water-plant relationships, Root zone, Water
utilization.

By means of a root-compartment technique, the effect of non-uniform distribution of
salts in the soil on alfalfa growth and water uptake was studied at Riverside, Calif-
ornia.  The root system was divided by a horizontal wax membrane into two equal depth
sections.  Each chamber was salinized and irrigated separately through a wick distri-
bution system.  It was found that mean salinity of the root zone was a good estimate
of effective salinity and that the salinity of both chambers was equally significant
in causing yield reductions.  Water uptake from each chamber was strongly influenced
by salinity of both chambers.  It decreased as salinity of the chamber increased and
increased at about half the rate as salinity of the complementary chamber increased.
Total plant water potentials were also computed from water-uptake rates and soil-
water potentials, using linear-flow equations.
                                      69

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 68-69:02I-020
 AERODYNAMIC  AND  SURFACE  FACTORS  IN EVAPORATION,
 Szeicz,  G.,  and  Endrodi,  Gabriella.  and  Tajchman,  S.
 Rothamsted Experimental  Station,  Harpenden,  Hertfordshire  (England) .
 Water  Resources  Research,  Vol.  5,  No.  2,  p  380-394, April  1969.   6  fig,  3 tab, 44
 ref .

 Descriptors:   *Evapotranspiration,  *Evaporation,  *Crops, Energy budget,  Diffusion,
 Advection, Stomata,  Winds,  Turbulence, Solar radiation.
 Identifiers:   Eddy conductivity,  Roughness  (Aerodynamic).

 Measurements were  made of the  roughness  length and other aerodynamic qualities of
 pine forest, lucerne, and potatoes in  Germany, and analyzed with  additional data
 obtained from  publications.  For  pliable  crops, roughness  length  decreases by 1/2 for
 winds  of 1-3 m/sec;  in this  range  of winds,  roughness  length  is approximately equal
 to 1/10  the  crop height.   Eddy conductivities are  about 3  times open-water values for
 crops  and 30 times open-water  values for  trees.   Stomatal  diffusion resistance values
 in trees are always 2-4  times  as  great as in crops, with winds from 1.0-1.5 cm/sec.
 Energy balance computations  give  estimates  of evaporation  for open  water, pine forest,
 potatoes, and  lucerne that agree  within  5-15% with measurements in  England and Calif-
 ornia.
 6S-69:02I-021
 INFLUENCE  OF TEMPERATURE AND  LEACHATE  ON  GERMINATION OF ATRIPLEX POLYCARPA,
 Cornelius,  D.  R.,  and  Hylton,  L.  0.
 Agricultural Research  Service,  Berkeley,  California.
 Agronomy Journal,  Vol.  61, No.  2,  p  209-211, March-April  1969.  3 fig, 2 tab, 3 ref.

 Descriptors:   Browse utilization,  Range management, Ranges, *Inhibitors, Plant growth
 substances, *Germination, Plant growth, *Vegetation establishment, Soil moisture,
 *Soil  temperature.
 Identifiers:   *Desert  saltbush, *Atriplex polycarpa, *Browse plant.

 Desert  saltbush, Atriplex polycarpa, a valuable native browse plant, occurs on dry
 rangeland  in central and southern  California.  Germination was determined at tempera-
 tures  from 5 to  35C at  5° intervals.   Highest germination occurred at 20C on the 5th
 day in  germinators and  at 15C  after  14 and  30 days.  Germination declined uniformly
 from the 15 or 20C level to lowest and highest temperatures.  For treatment A one set
 of seed and blotters was moistened with tap water for duration of 30 days.  In treat-
 ment B  the  seed was soaked  (leached) for  48 hours; then tap water was used to keep
 blotters and seed  moist.  In  treatment C  seeds were kept moist by using the leachate
 from the seed  that had  been soaked.  Highest germination occurred after treatment B;
 lowest  after treatment  C; and  treatment A was between C and B in effectiveness.  The
 presence of some undetermined  substances  in the leachate  severely inhibited germina-
 tion in treatment  C.  Partial  removal of  the leachate from the seed enhanced germina-
 tion in treatment  B.
63-69:021-022
PLANT MOISTURE STRESS:  A PORTABLE FREEZING-POINT METER COMPARED WITH THE PSYCHRO-
METER,
Cary, J. W., and Fisher, H. D.
Snake River Conservation Research Center, Kimberly, Idaho.
Agronomy Journal, Vol. 61, No. 2, p 302-305, March-April 1969.  5 fig, 2 tab, 11 ref.

Descriptors:  *Diffusion, *Moisture stress, *Hygrometry, Soil-water-plant relation-
ships .
Identifiers:  *Plant-water relations, *Freezing-point depression.

A small portable instrument for measuring the freezing-point depression of plant
tissue has been developed for field use.  The instrument is easy to operate and can
be constructed from, materials costing less than S100.  Moisture stress measurements
made with the freezing-point meter on a variety of plants were compared with vapor
pressure psychrometer measurements.  Variation between duplicates in the freezing
point averaged 1.2 bars, but differences between stress measurements made with the
psychrometer and freezing-point instrument averaged 2.6 bars.

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68-69:02I-023
SURVIVAL OF PLANTS UNDER PROLONGED FLOODED CONDITIONS,
Yu, P.  T., Stolzy, L. H., and Letey, J.
California University, Riverside, Dept of Soils and Plant Nutrition.
Agronomy Journal, Vol. 61, No. 6, p 844-846, November-December 1969.  2 tab, 2 ref.

Descriptors:  *Aeration, Corn, Tomatoes, Barley, *Flooding, Root systems, Soil-plant-
water relationships.
Identifiers:  *Root porosity, *Internal aeration, Flooded treatments.

Barley (Hordeum vulgare L.;, corn (Zea mays L .)  , sunflower (Helianthus annus L.),
tomato (Lycopersicum esculentum L.), and "Pato" and "Inia" varieties of wheat
(Triticum vulgare L.) were grown in Kriiium-stablized Yolo loam in pot culture under
greenhouse conditions until the root systems were well established.  The plants were
then subjected to full-flooded, half-flooded, and temporarily-flooded treatments.
Observations of plant growth rates under treatments were made by periodically measur-
ing top and root length.  Plants were harvested after 2 to 4 weeks of treatment and
the air-filled root porosity was measured for each root system.  Reduction in growth
rates and dry weights for all plants was observed in full-flooded as compared to
non-flooded conditions.  These results suggest that tolerance to excess moisture was
related to plant internal aeration which might be achieved by increases in root por-
osity.   Reduction in weight and growth rates was significant in full-flooded but not
significant in half-flooded conditions when compared to control.
68-69:02I-024
EFFECTS OF TILLAGE, NO TILLAGE, AND MULCH ON SOIL WATER AND PLANT GROWTH,
Jones,  J. N., Jr., Moody, M. E., Lillard, J. H.
Agricultural Research Service, Blacksburg, Virginia
Agronomy Journal, Vol. 61, No. 5, p 719-721, September - October, 1969.  2 fig, 3 tab,
7 ref.
(See 68-69:03F-027)

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                                     SECTION VII

                 WATER CYCLE - EROSION AND SEDIMENTATION (Group 02J)


68-69:02J-001
INTERDEPENDENCE OF WATER DROP ENERGY AND CLOD SIZE ON INFILTRATION AND CLOD STABILITY,
Moldenhauer, W. C., and Kemper, W. D.
Iowa State University, Ames, Dept of Agronomy.
Soil Science Society of America Proceedings, Vol. 33, No. 1, p 297-301, January -
February 1969.  8 fig, 3 tab, 17 ref.

Descriptors:  *Infiltration, *Impact (Rainfall), *Soil structure, *Soil surface,
*Runnoff, Soil erosion.
Identifiers:  Soil surface sealing.

The decline of intake rates as successive increments of water drop energy were
applied to various sizes of soil fragments of two Iowa and two Colorado soil types is
presented.  There was a wide spread between intake rate of the 8- to 20-mm size range
and those of all other sizes after the first increment (1.25 cm as 5-mm drops) was
applied.  The intake rate of the 8- to 2-mm size declined rapidly after the first
or second increment.  Final intake rates were not correlated with aggregate stability
in this study.  There was a negative correlation between clay content and final in-
take rates.  Final intake rates after disintegration of large soil fragments in many
cases were lower than when initial size ranges were small.
68-69:02J-002
ADSORPTION OF PHOSPHORUS BY LAKE SEDIMENT,
Harter, R. D.
Connecticut Agricultural Experiment Station, New Haven.
Soil Science Society of America Proceedings, Vol. 32, No. 4, p 514-518, July-August
1968.  5 fig, 1 tab, 12 ref.

Descriptors:  *Sediments, *Phosphorus, Eutrophication, Algae.
Identifiers:  *NaOH and NH.F extractable phosphorus

The sediment of a eutrophic lake is capable of adsorbing a large amount of phosphorus
from the water.  To study the sorption mechanism, between 0 and 2.2 mg P was added to
0.1-g sediment samples  (1:50 sediment-solution ratio).  After equilibrium had been
established, P remaining in solution was determined, and adsorbed P was extracted
with 0.5N NH.F and O.lN NaOH.  Whereas all P adsorbed into the NaOH-extractable frac-
tion appeared to occur as an iron phosphate, NH,F apparently extracted P bonded by
two different mechanisms.  When less than about 0.1 mg P was added, NH.F extracted a
tightly bonded form of P, probably occurring as an aluminum phosphate.  When more
than 0.1 mg P was added, additional P in a more loosely bonded form was adsorbed
into the NH.F-extractable fraction.  The loosely bonded P appeared to be independent
of Al content of the sediment, and could be removed by successive water extraction.
The capability of the sediment to adsorb considerably loosely bonded P means that
large influxes of P into the lake may be held temporarily and subsequently released
to growing plants and algae.
68-69:02J-003
A SYSTEM FOR MEASURING AND SAMPLING RUNOFF CONTAINING SEDIMENT AND AGRICULTURAL
CHEMICALS FROM NEARLY LEVEL LANDS,
Willis, G. H., Laflen, J. M., and Carter, C. E.
Agricultural Research Service, Baton Rouge, Louisiana.
American Society of Agricultural Engineers, Transactions, Vol. 12, No. 5, p 584-587,
September-October 1969.  1 fig, 4 tab, 7 ref.

Descriptors:  *Sediments, Chemicals, Water resources, Agriculture, Head loss, *Run-
off, Samplers, Rainfall, Watersheds (Basins), Parshall flumes, Weirs, Volume, Analy-
sis, Endrin, Chromatography, Clays, Water pollution, Silts, Pollutants, Models,
*Agricultural chemicals, Measurement,  *Water pollution sources, Pesticides, Nitrates,
Water analysis.
Identifiers:  Coshocton sampler.
                                      73

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 Controversies over suggestions that agricultural  chemicals  might be  polluting water
 resources of this  nation make  it imperative  that  the  quality  of runoff  from agricul-
 tural lands be characterized accurately.   To do this,  special care must be exercised
 to collect samples that truly  represent the  runoff.   A Parshall flume,  Geib multislot
 divisor,  sump pump,  and storage tanks,  appropriately  arranged, provided a system  that
 measured  runoff with reasonable accuracy  and collected representative samples of  the
 runoff.   Very little head loss through  the system was  experienced.   The vertical  dis-
 tance from the flume entrance  to the divisor outlet was only  4.5 in.  There were
 little differences in silt,  clay,  N03-N,  or  endrin contents in overall  comparisons
 between slot and channel samples for all  flow rates and sediment concentrations test-
 ed.   All  endrin entering the system was recovered, proportionately,  in  the sample.
 68-69:02J-004
 SOIL  EROSION CONTROL  PRACTICES  IN  PERSPECTIVE,
 Jacobson,  P.
 Harza Engineering  Company,  Chicago,  Illinois.
 Journal  of Soil  and Water Conservation, Vol.  24, No. 4, p  123-126, August 1969.
 2  fig, 10  ref.

 Descriptors:  *Soil erosion,  *Erosion control,  *Check structures, *Farm management,
 Contour  farming, Embankments, Land forming, Land management, Slope protection, Soil
 conservation, Strip cropping, Terracing, Water  control.
 Identifiers:  *Tillage practices.

 Many  standard soil erosion  control practices  have proven impossible to sell to far-
 mers,  and  some are no longer  applicable to farming practices now in use.  The stand-
 ard practices are  reviewed  and  suggestions are  made for their modification or replace-
 ment  in  cases of lack of use  or obsolescence.   Contouring  is not suitable for large-
 scale  mechanized farming in humid  areas.  Crop  rotation is no longer necessary to add
 nitrogen,  and is not used by  farmers who do not need grass crops.  Strip cropping is
 seldom used in corn areas or  by non-users of  grass.  Terracing is effective if con-
 structed properly but more  research on the relation of terrace shape to land and
 climate  conditions is needed  to utilize the system well.  Tillage practices are used
 well  in  many cases, but more  need  to be established for various crop-weather-runoff
 situations.  It  is concluded  that  Corn Belt farmers will accept only no-flow till-
 plant  minimum tillage programs with water control by storage fills across waterways.
 Use of this system can reduce downstream sediment and nutrient loads to very low
 levels.
68-69:02J-005
USE OF RADIOACTIVE 59Fe FOR TRACING SOIL PARTICLE MOVEMENT  PART I. FIELD STUDIES OF
SPLASH EROSION,
Coutts, J. R. H., Randil, M. F., Nowland, J. L., and Tinsley, J.
University of Aberdeen, Dept of Soil Science.
Journal of Soil Science, Vol. 19, No. 2, 1968.  6 fig, 3 tab, 3 plates, 5 ret.

Descriptors:  *Rainfall, *Impact rainfall, *Soil erosion, Soil mechanics, Wind eros-
ion, Slopes, Raindrops, *Radioactivity techniques.

-^Fe appeared to be a suitable tracer for investigating soil particle movements and
experimental results have demonstrated quantitatively that, when a dilute radioactive
FeCl^ solution is applied to soils of varied texture, this isotope is firmly absorbed
and shows little tendency to downward movement by leaching.  Addition of the chelat-
ing compound di-ethylene triamine penta-acetic acid  (DTPA) greatly improves the
uniformity of absorption.  The surface movement of labelled soil particles was read-
ily detected by direct scintillation counting of grid reference points over trays of
soil exposed in the field or of core samples transported to the laboratory, and less
sensitivity by autoradiographs on X-ray film applied to the surface of ground plots.
Under the summer and winter weather conditions prevailing at Aberdeen, the displace-
ment of soil from bare surfaces by rain splash is markedly affected by wind speed
and direction.  Even with light showers, relatively low wind speeds and slopes not
exceeding 6°, some of the labelled soil particles migrated distances of 60 cm from
the treated areas in the centre of ground plots 2 m square.
                                      74

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68-69:02J-006
USE OF RADIOACTIVE 59Fe FOR TRACING SOIL PARTICLE MOVEMENT  PART II.  LABORATORY
STUDIES OF LABELLING AND SPLASH DISPLACEMENT,
Coutts, J. R. H,, Kandil, M. F., and Tinsley, J.
University of Aberdeen, Dept of Soil Science.
Journal of Soil Science, Vol. 19, No. 2, 1968.  6 fig, 9 tab, 9 ref.

Descriptors:  *Rainfall, *Impact rainfall, *Soil erosion. Soil mechanics,  Wind eros-
ion, Slopes, Raindrops, *Radioactivity techniques.

The field studies reported in Part I were complemented by laboratory  investigations
on the labelling of soils and the movement of soil particles by simulated  rainfall
splash.  Of various labelling techniques tested, the most uniform absorption of
as  shown  by autoradiographs,  was secured by adding DTPA chelating reagent to the
FeCl, solution used for wetting soil peds under vacuum.  Studies on the specific rad-
ioactivity of the Atterberg textural fractions, separated from clay loam,  sandy loam,
loam and peat soils before and after labelling, showed in all cases that the clay
fraction was dominant in retention of  "Fe.  The radioactivity was so firmly absorbed
that its movement could be used to trace both the horizontal and vertical  displace-
ments of labelled soil particles by scintillation counting of autoradiographic tech-
niques.  Tests with a rainfall, simulator showed a close correlation between the
weights and radioactivities of splashed soil particles.  Gravimetric  data  obtained
from unlabelled clay loam and sandy loam soils subjected to  'rainfall1  of  differing
intensity, drop size and height of fall gave a linear relationship on a logarithmic
scale between mass of particles and distance of splash.  Calculation  of the kinetic
energy lost by water drops on impact with the soil and that imparted  to the splashed
soil particles show that the relationship depends principally on the  rainfall inter
sity and the texture of the soil.
68-69:02J-007
SOIL MOVEMENT ON IRREGULAR SLOPES,
Young, Robert A., and Mutchler, Calvin K.
Agricultural Research Service, Morris, Minnesota.
Water Resources Research, Vol. 5, No. 5, p 1084-1089, October 1969.  2 fig, 4 tab,
11 ref.

Descriptors:  *Soil erosion, *Model studies, *Simulated rainfall, Gully erosion, Rill
erosion, Sheet erosion, Runoff, Slopes, Topography, Soil conservation, Rainfall
intensity, Tracers, Dye releases.
Identifiers:  Soil erosion test plots, Soil movement tracers.

Soil loss and runoff were measured from concave, uniform, and convex slopes subjected
to simulated rainfall.  Fluorescent glass particles and microrelief measurements were
used to determine soil movement patterns in the slopes.  For slopes of equal average
steepness, a concave shape greatly reduced the total sediment loss in comparison with
that from either a uniform or convex slope.  Average slope steepness was not a good
indicator of soil delivery past a given point except for a uniform slope.  In general,
soil losses from irregular slopes depend on the steepness of a short section of that
slope immediately above the point of measurement.  Soil movement off the plots was
primarily transported by raindrop splash to a rill system and then transported down
the slope by runoff in the rill system.  A breakdown of the rill system occurred on
the bottom of the concave slopes because of decreasing local steepness, resulting in
sheet flow and sediment deposition.
68-69:02J-008
GRADED FURROWS FOR WATER EROSION CONTROL,
Richardscn, C. W. ,  Baird, R. W.,  and Fryrear,  D. W,
Blacklands Experiment Watershed,  Riesel,  Texas.
Journal of Soil and Water Conservation, Vol. 24, No. 2, p 60-63, March-April 1969.
5 fig, 2 tab, 4 ref.

Descriptors:  *Furrow systems, *Erosion control, *Grading, *Runoff, *Slopes, Terrac-
ing, Irrigation efficiency, Texas, Crop production, Demonstration watersheds. Cul-
tivated lands, Peak discharge.

At the Blackland Research Center, Temple, Texas, and the Blacklands Experimental
Watershed, Riesel,  Texas, research is underway to evaluate the effectiveness of a
system of graded furrows as an erosion control measure.  A system of furrows with a


                                     75

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 1 percent grade successfully controlled erosion on areas  with  slopes  up  to  3 percent.
 Operating farm equipment on the furrow ridges  was  not appreciably  more difficult
 than on flat-tilled areas,  and crop yields were comparable  to  yields  obtained on
 nearby conventionally tilled areas.  Runoff and soil  loss data from graded  furrows
 up to 930 feet long indicated that both unit runoff and soil loss  increased as  fur-
 row length increased.  Graded furrows appeared to  be  a method  of increasing the effi-
 ciency of field operations  while protecting the soil  from erosion.
 68-69:02J-009
 USE  OF  TRACER  TECHNIQUE  IN  SOIL  EROSION  RESEARCH,
 McHenry,  J.  Roger.
 Agricultural Research  Service, Oxford, Mississippi.
 American  Society  of  Agricultural Engineers  Transactions, Vol.  11, No. 5, p 619-625,
 September-October 1968.   2  fig,  2 tab, 31 ref.

 Descriptors:   *Tracers,  *Radioisotopes,  *Soil erosion, Tagging, Alpha rays, Tritium,
 Beta rays, Gamma  rays. Bibliographies, Sampling, Half  life, Radioactivity, Research
 equipment, Radiation measurement,  Soil science, *Erosion.
 Identifiers:   Scintillation  counters.

 A review  is  given for  those  considering  the use of radioactive tracers in soil eros-
 ion  research.  The selection and characteristics of a  tracer,  including half life,
 specific  activity, type  of emission, and chemical and  physical form are discussed.
 The  method for calculating the required  amount of the  tracer is described; the gen-
 eral theory  of using tagged  particles as tracers and of isotopic dilution is given.
 Selecting and  preparing  a radioisotope,  and tagging and seeding particles in the
 experimental area, are described.  Methods  are outlined for detection, sample count-
 ing,  and  data  reduction.  Advantages and disadvantages are presented for using radio-
 isotopes  as  tracers.   In erosion research,  the measurement of volume movement of a
 soil mass is difficult to evaluate.  If  the entire soil mass can be traced or if the
 tracer  can be  mixed  uniformly in the system samples, quantitative results can be
 calculated.  These conditions do not usually occur and the result is that tracer
 data are  more  qualitative than quantitative.
68-69 :02J-010
EFFECT OF EROSION-CONTROL LAND TREATMENT ON FLOW FROM AGRICULTURAL WATERSHEDS,
Harrold, Lloyd L., and Dragoun, Frank J.
Agricultural Research Service, Washington, D.C.
American Society of Agricultural Engineers Transactions, Vol. 12, No. 6, p 857-861,
November-December 1969.  8 tab, 16 ref.

Descriptors:  *Flow, *Water yield, *Land treatment, *Agricultural watersheds, *Eros-
ion-control, Storm runoff, Terraces.
Identifiers: *Coshocton, Ohio; *Hastings, Nebraska; *Riesel, Texas; *Treynor, Iowa;
Deep loess.

Farming methods that increased the area of grass and trees effectively reduced soil
erosion and caused a reduction in annual surface water yield by about 30 percent in
Ohio, Nebraska, and Texas.  Although level bench terraces in deep loess of western
Iowa has little effect on total annual water yield, its stream flow came mostly from
aquifers and was distributed fairly uniformly throughout the year.  On unterraced
watersheds, much of the flow occurred as flashy storm surface runoff.  These level
terraces caused noticeable reduction in flood peak discharge rates.  Major flood
peaks in Ohio, Nebraska, and Texas were not affected by erosion-control land treat-
ment.  Watershed modeling techniques are not yet advanced to the point of predicting
downstream effects on streamfiow resulting from headwaters land use changes.
68-69 :02J-011
EFFECTS OF UNIT WEIGHT AND SLOPE ON EROSION,
Foster, Richard L,, and Martin, Glen L.
Cornell,Howland, Hayes and Merryfield, Seattle, Washington.
American Society of Civil Engineers Proceedings, Journal of Irrigation & Drainage
Division, Vol. 95, No. IR4,  Paper No. 6984, p 551-561, December 1969.  9 fig, 2 tab,
6 ref,  append.
                                      76

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Descriptors:  *Erosion, *Soil erosion, *Slopes, *Soil compaction. Drainage,  Rainfall,
Roads, Rainfall-runoff relationships, Model studies. Laboratory tests.  Statistical
methods.
Identifiers:  Slope-erosion relations.

Laboratory tests were performed on a fine grained soil to determine the effect of unit
weight and slope on erosion and runoff.  The tests were conducted on slopes  of 1:1,
2:1, and 3:1 using unit weights of 80, 85, 90 and 95 Ib per cu ft and a simulated
rainfall intensity of 6 in. per hr.   After collecting the runoff water  and solid par-
ticles, the weight of solids eroded  and the volume of runoff water were determined.
The results and analyses of this study indicate that the slope and unit weight have
definite effects on the erosion of unprotected slopes.  These indications are: (1)
On the flattest slope, the specimens compacted to the lowest unit weight experience
the highest rate of erosion; (2) on  the steepest slope, the specimens compacted to
the highest unit weight experience the highest rate of erosion; and (3) for  a given
unit weight, there is a unique slope from which the maximum amount of erosion will
occur.
68-69:02J-012
RELATION OF SOIL PROPERTIES TO ITS ERODIBILITY,
Wischmeier, W. H.,  and Mannering, J. V.
Agricultural Research Service, Lafayette, Indiana.
Soil Science Society of America Proceedings, Vol. 33, No. 1, p 131-137, January-
February 1969.  1 fig, 4 tab, 17 ref.

Descriptors:  *Soil erosion, *Runoff, *Soil physical properties, Soil conservation,
Erosion control, Soil stability. Soil strength, Bulk density, Particle size, Soil
structure. Soil aggregates, Permeability, Porosity, Soil texture, Saturation, Sands,
Silts, Clays, Organic matter, Hydrogen ion concentration, Crops> Grasses, Slopes.
Identifiers:  Soil-loss prediction, Soil erodibility, Soil detachment.

A soil's inherent erodibility, which is a major factor in erosion prediction and
land-use planning,  is a complex property dependent both on its infiltration capacity
and on its capacity to resist detachment and transport by rainfall and runoff.  The
relations of these capacities to soil physical and chemical properties were investi-
gated in a 5-year field, laboratory, and statistical study including 55 selected
Corn Belt soils.  Properties that contributed significantly to soil-loss variance
included percentages of sand, silt, clay, and organic matter; pH, structure and bulk
density of plow layer and subsoil; steepness and concavity or convexity of slope;
pore space filled by air; residual effects of sod crops; aggregation; parent material;
and various interactions of these variables.  An empirical aquation was derived for
calculating the universal soil-loss equation's erodibility factor K for specific
soils.  Tests of the equation against soils of the older erosion-research stations,
for which the erodibility factor is known, substantiated its general applicability
over a broad range of medium-textured soils.
68-69:02J-013
INTERRELATIONSHIP BETWEEN PHYSIOGRAPHY, HYDROLOGY, SEDIMENTATION, AND SALINIZATION
OF THE LODDON RIVER PLAINS, AUSTRALIA,
Macumber, P. G.
Geological Survey of Australia, Melbourne.
Journal of Hydrology, Vol. 7(1969), No. 1, p 39-57, November 1963.  5 fig, 1 plate,
2 tab, 18 ref.

Descriptors:  *Saline soils, *Saturated soils, *Land reclamation, *Drainage, Irri-
gation practices, Flood control, Leaching, Alluvium, Water table.
Identifiers:  Australia, Loddcn River, Aaolian soils.

The causes of salinization of the Loddon River plain, Australia, were studied to
attempt to find a means of halting the deterioration of irrigated farms and grazing
land.  The pattern of salinization was found to be closely linked to the fluvial and
aeolian patterns of Quaternary sedimentation, with the most severe salinization in
clays and fine soils.  Flood control projects eliminated the winter sheet flood
which leached salt from the upper soil profile each year, while summer irrigation
causes rising water tables and soil salinization.  Alluvial sand aquifers are found
along some of the streams; pumping them heavily as groundwater drains can be done
locally to lower the water table and alleviate soil salinity.  Buried alluvial aqui-
fers parallel to surface drainage were found and may also be pumped for drainage.
                                      77

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 68-69 :02J-014
 SOIL EROSION AND CONSERVATION IN NORTHERN JORDAN,
 Beaumont,  P.,  and Atkinson,  K.
 Durham University (England),  Dept of Geography.
 Journal of Soil and  Water Conservation,  Vol.  24, No.  4,  p  144-147, August 1969.
 4  fig.

 Descriptors:   *Soil  erosion,  *Erosion control,  *Social aspects, Farm management, Land
 management,  Soil conservation,  Governments, Vegetation establishment, Water control,
 Cover crops.
 Identifiers:   *Jordan.

 The way of life of the  people in northern Jordan promotes  continued misuse of the
 land and hinders the adoption of erosion control programs.   In work completed thus
 far, attention has been almost  exclusively concentrated  on improving areas of land
 owned by the government.   Relatively little consideration  has been given to the im-
 provement of agricultural practices which are,  in  the final analysis, the root cause
 of the  erosion problem.   The  government's role  in  new programs should be confined to
 financing large capital projects,  for example,  dam construction, and intensifying
 research concerning  the relative productivity of different agricultural patterns and
 crops.   Villages should implement conservation  at  the local level under their own
 initiative.  This will  be difficult to instigate in a traditionally rural society.
 68-69:02J-015
 SEDIMENTATION  IN  THE  NATION'S  RESERVOIRS,
 Dandy,  Farris  E.
 Agricultural Research Service,  Oxford, Mississippi.
 Journal of  Soil and Water Conservation, Vol.  23, No.  4, p  135-137, July-August 1968.
 5  fig,  1 tab,  15  ref.

 Descriptors:   *Reservoir silting,  Sediment yield, Reservoir  storage, Trap efficiency.
 Identifiers:   Reservoir storage depletion.

 Reservoir sedimentation data compiled by the  U.S. Department of Agriculture Sedimen-
 tation  Laboratory are summarized.   The Nation's  968 reservoirs range from small ponds
 to over 1 million acre-ft.  Annual average storage loss was  150,000 acre-ft, about
 0.2% of initial total capacity,  well within the  design requirements of most reser-
 voirs.   Average depletion rates are much higher  in reservoirs of 100 acre-ft or less,
 which account  for only a small  part of total  reservoir capacity, but are 40% of the
 total number of reservoirs.  Depletion was less  than  1% for  58% of the reservoirs
 larger  than 100,000 acre-ft, over  3% for 15%  of  the reservoirs, and in excess of 10%
 for only 2% of the reservoirs.   Average sediment accumulation rates, in general, de-
 crease  as drainage area increases.  Prediction of depletion  rates can be successful
 only if local  empirically determined relationships are used.  The conclusions reached
 are that the depletion rate of  0.2% is not alarming,  the 3%  rate in small upland
 reservoirs  seems  excessive, and if present rates continue, about 20% of small reser-
 voirs will  be  half filled with  silt in 30 years.
68-69-.02J-016
SMALL AMOUNTS OF SURFACE MULCH REDUCE SOIL EROSION AND RUNOFF VELOCITY,
Kramer, L. A., and Meyer, L. D.
Agricultural Research Service, Lafayette, Indiana.
Transactions of the American Society cf Agricultural Engineers, Vol. 12, No. 5,
p 638-641, September 1969.  8 fig, 2 tab, 15 ref.

Descriptors:  *Erosion, *Rill erosion, Soil erosion, *Erosion control, Impact  (rain-
fall) , Slope stability, Runoff, Simulated rainfall, *Mulching, Water management
(Applied).

This paper presents results of a study of various rates of surface mulch as they
affect soil loss and runoff velocity under a broad range of degrees and lengths of
slope.  Tests were conducted under controlled laboratory conditions on two soil par-
ticle sizes composed of glass spheres averaging 33 and 121 microns in diameter.
Erosion rate and runoff velocity were measured for a factorial set of the following
treatment levels:  mulch rate - equivalent to straw at 0, 1/8, 1/4, 1/2, and 1 ton
per acre; slope steepness - 4, 6, 8,  and 10 percent; slope length - equivalent to
40,  70, and 100 ft at a runoff rate of 1.5 in per hr.  All treatment level combina-
_ions were tested randomly within ea;h soil particle size group.  The length of a


                                      "3

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test or run was 30 min.,  unless a very high erosion rate limited it to a shorter
period.  Compared with no-mulch conditions, mulch rates of 1/2 to 1 ton per acre
greatly reduced the erosion rate and runoff velocity for a wide range of slope steep-
nesses and lengths.  Lower mulch rates effectively reduced erosion of fine-sand size
but not silt-size particles.  Much of the effectiveness of a surface mulch applica-
tion in reducing erosion and runoff velocity was lost when rilling, or flow under the
mulch layer, occurred.
68-69:02J-017
CONTROLLING WATER EROSION WITH GRADED ROWS,
Carter, C. E., and Carreker, J. R.
Agricultural Research Service, U.S. Department of Agriculture.
Transactions of the American Society of Agricultural Engineers,  Vol. 12,  No.  5,
p 677-680, September 1969.  4 fig, 5 tab,  7  ref.

Descriptors:  *Erosion, Corn, Runoff, Agriculture, Rainfall.
Identifiers:  Graded-row concept of controlling erosion.

Graded rows effectively controlled erosion from sloping loess soil.   Measurements
showed that graded rows reduced erosion 44 percent over non-graded rows,  and  during
one series of storms, graded rows reduced  erosion 78 percent  over up-and-down-hill
rows.  Frequent row breakages, particularly  on the steeper slopes, caused variation
in the amount of erosion among slopes; however, during storms where no row breakover
occurred, there was no significant difference between runoff  or  erosion and slope.
Corn yield increased as slope steepness decreased.
                                      79

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                                    SECTION VIII


                    WATER CYCLE - CHEMICAL PROCESSES  (Group 02K)


68-69:02K-001
THE MOVEMENT OF RADIOACTIVE SODIUM AND RUTHENIUM THROUGH A SIMULATED AQUIFER,
Champlin, J. B. F., and Eichholz, G. G.
Georgia Institute of Technology, Atlanta.
Water Resources Research, Vol. 4, No. 1, p 147-158, February 1968.  8 fig, 20 ref.

Descriptors:  *Groundwater, *Pollution, *Soils, Radioactivity, Aquifer, Sodium,
Potassium, Calcium.

The interaction of water solutions with the particulate matter composing a natural
aquifer is of steadily increasing interest with the new emphasis on pollution of our
natural resources.  As a means of studying the contribution made by water to the
transport of ionic materials through soils, radioactive solutions were injected into
a model aquifer containing 725 kg of sand with dimensions of 1x2x0.25 meters.  As the
radioactivity passed through the sand, its progress was followed by a collimated
Geiger Muller tube situated on the exterior of the bed.  The appearance of the radio-
activity in the effluent, which marked the arrival of the sodium front, was found to
be correlated with an increase in suspended particulate matter, potassium and calcium
concentrations, and overall conductivity.  Of particular significance was the portion
of the radioactivity shown to be related directly to the filterable mass of particles
in the effluent, despite the high solubility of the ion used.  The results with the
sodium were compared with those of similar tests on the movement of trivalent ruth-
enium, which is not soluble at the pH of the solutions used.  Both the sodium and
ruthenium studies indicated that a significant amount of radioactivity was transpor-
ted through the test bed on particulate matter which was large enough to be trapped
on 0.45 micron membrane filters.
68-69:02K-002
REDUCTION OF SULFATE TO SULFIDE IN WATERLOGGED SOIL,
Connell, W. E., and Patrick, W. H-, Jr.
Louisiana State University, Alexandria, Dept of Agronomy.
Soil Science Society of America Proceedings, Vol. 33, No. 5, p 711-715, September-
October 1969.  6 fig, 1 tab, 9 ref.

Descriptors:  *Sulfate, *Sulfides, *Saturated soils, *Anaerobic conditions, Sulfur
compounds, *Reduction, Soil chemistry, Oxidation-reduction potential.

A study was made of sulfate reduction to sulfide in waterlogged soils supplied with
an energy source.  Sulfate reduction was more rapid in surface soil than in subsur-
face layers with sulfide appearing 2 days after waterlogging samples of a surface
soil.  The amount of sulfide precipitated from added ^S in two soils was approxi-
mately equivalent to the amounts of ferrous iron released by waterlogging.  Added
Fe203 was effective in precipitating H2S.  Sulfate reduction was retarded by nitrate.
Addition of oxygen to highly reduced soils caused a rapid decrease in sulfide cont-
ent, with one-half of the sulfide being oxidized in 15 minutes and all the sulfide
oxidized after 8 hours.
68-69:02K-003
CROP SEEDLING UPTAKE OF DDT, DIELDRIN, ENDRIN,  AND HEPTACHLOR FROM SOILS,
Beall, M. L., Jr., and Nash, R. G.
Agricultural Research Service, Beltsville, Maryland.
Agronomy Journal, Vol. 61, No. 4, p 571-575, July-August 1969.  4 tab, 24 ref.

Descriptors:  *Insecticides, Pesticides, Residues, Absorption, Alfalfa, *Endrin,
*DDT, Heptachlor, Crops.
Identifiers:  Crop seedling.

In greenhouse experiments, soybean, wheat, corn, alfalfa, bromegrass, and cucumber
seedlings took up various amounts of DDT, dieldrin, endrin, and heptachlor residues
fro- five soils treated with 0.5 or 5.0 ppm insecticide.  Residue concentrations in
plants were usually well below the soil treatment rates, though endrin and heptachlor
residues in alfalfa and bromegrass exceeded the treatment rate of some soils.  The


                                      81

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 order  of  residue  uptake  in  increasing amounts was DDT  < dieldrin < endrin < heptach-
 lor.   Correlations  calculated between residues  in seedlings and several soil charac-
 teristics revealed  that  organic  matter negatively affected the uptake of DDT, dield-
 rin, and  heptachlor.   Silt  negatively affected  endrin  uptake.  Soil moisture content
 at  0.33 bar  tension negatively affected DDT and dieldrin uptake by alfalfa.  No
 significant  correlations were found between uptake and soil pH, cation exchange ca-
 pacity, or clay content.  Soil analysis, 14 or  20 months after insecticide applica-
 tion,  revealed residues  of  the insecticides, in increasing order of persistence, to
 be  heptachlor < dieldrin ~  endrin  < DDT.  Correlations calculated between residues in
 soils  and the soil  characteristics above revealed that persistence was positively
 correlated with soil  organic matter.
 68-69:02K-004
 AVAILABILITY CHARACTERISTICS OF AND PLANT RESPONSE TO NITROGEN SOURCES,
 McCants, C. B.
 North Carolina  State University, Raleigh, Dept of Soil Science.
 Agronomy Journal, Vol.  61, No. 3, p 353-356, May-June 1969.  2 fig, 6 tab, 10 ref.

 Descriptors:  *Nitrogen, *Fertilizers, *Leaching, Tobacco, Moisture content, Ureas.
 Identifiers:  Nitrogen  availability. Plant response to nitrogen, Controlled release
 fertilizers. Cottonseed meal.

 The relative availability characteristics of nitrogen in urea, cottonseed meal, a
 commercial urea-formaldehyde product, and an experimental urea-wax material were
 studied through successive leachings in model lysimeters in the laboratory and by
 leaching and plant growth in the greenhouse.  The effects of the nitrogen sources on
 yield and chemical composition of field-grown tobacco were studied under different
 moisture regimes.  The  total release of nitrogen from the urea-wax source was compar-
 able to that from urea  but significantly higher than from urea-formaldehyde or cot-
 tonseed meal sources.   The rate of N release during the first 21 days was not differ-
 ent among the urea-wax, urea-formaldehyde, and cottonseed meal sources; thereafter,
 it was higher from urea-wax.  When differences in crop response occurred among the
 different sources, the  yield and quality index were higher from urea-wax than from
 cottonseed meal or urea-formaldehyde.  These results and data from other research
 suyaest that the probability of practical contributions of slow release fertilizers
 in the commercial oroduction of annual field crops is quite small.
68-69:02K-005
EFFECT OF TIME AND METHOD OF NITROGEN APPLICATION AND SOURCE OF NITROGEN ON THE
YIELD AND NITROGEN CONTENT OF CORN,
Stevenson, C. K., and Baldwin, C. S.
Ridgetown College of Agricultural Technology, Ridgetown, Ontario, Canada.
Agronomy Journal, Vol. 61, No. 3, p 381-384, May-June 1969.  6 tab, 11 ref.

Descriptors:  *Ureas, Ammonium compounds, Nitrogen, Corn, Clays, Grains  (Crops).

Fall plowdown, spring preplant,  and side-dress applications of nitrogen were compared
in field experiments on Brookston clay, Brookston clay loam, and Haldimand silt loam
soils.  Ammonium nitrate, urea,  and anhydrous ammonia were compared at 56, 112, 168,
and 224 kg N/ha.  Spring application  (preplant or side-dress) produced higher grain
yields than fall application in all experiments regardless of the rate of nitrogen
applied.  Preplanting the nitrogen was as effective in increasing grain yield as the
side-dress method.  Yield results with fall-applied nitrogen were poorer on the clay
soil than the loam soils.  Spring application of nitrogen gave 370 to 2,610 kg/ha
higher yield of corn grain than fall application on clay soils, and 200 to 1160 kg/ha
higher yield of corn grain on the loam soils.  No rate of nitrogen applied in the fall
or in the spring.  The nitrogen content of the grain varied with the time and method
of application of nitrogen.  Grain from plots that received nitrogen in the fall was
markedly lower in percent nitrogen than grain from plots that received nitrogen in
the spring.
68-69:02K-006
TRAVEL OF NITROGEN IN SOILS,
Preul, H. C., and Schroepfer, G. J.
Minnesota University, Minneapolis, Dept of Civil Engineering.
Journal of the Water Pollution Control Federation, 'Vol. 40, No. 1, p 30-48, January
1968.  15 fig, 5 tab, 6 ref.


                                      82

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Descriptors:  *Adsorption, *Nitrogen, Saturation, Soils, Nitrification.
Identifiers:  *Laboratory-scale studies.

A laboratory-scale study of the movement of nitrogen through soil showed that adsorp-
tion and biological action are the main controlling factors.  Physical adsorption
inhibits the travel of NH4+N, but is limited by the presence of other ions.  Little
inhibition of N03~N occurs at wastewater pH.  Adsorption dominates and biological
interference with NH^ movement is minimal when oxygen is limited, e.g., when soil is
saturated.  Undar well-aerated conditions, nearly complete nitrification occurs with-
in a few feet of the influent surface.


68-59:02K-007
THE RESPONSE OF MACROBENTHOS TO IRRIGATION RETURN WATER,
Kreis, Douglas, and Johnson, William.
Robert S. Kerr Water Research Center, FWPCA, Ada, Oklahoma.
Journal of the Water Pollution Control Federation, Vol. 40, No. 9, p 1614-1621,
September 1968.  3 fig, 2 tab,. 7 ref.

Descriptors:  *Wastewater, *Maiyflies, *Caddisf lies, *3enthic, *L~.rvae, *Bloodworms,
*Annelids, *Macrobenthos, * Irrigation return water.
Identifiers:  Klamath River, California; Klamath River, Oregon; Lost River, Californ-
ia; Lost River, Oregon.

Macrobenthos communities of the Lose and Klamath Rivers of Oregon and California were
surveyed to determine the response of benthic macroinvertebrates to irrigation return
water.  Lost River macrobenthos populations changed from associations of mayfly
nymphs, and caddisfly and beetle larvae to associations of bloodworms and annelids.
These changes were related to downstream increases in irrigation return water.  De-
creases in mayfly nymphs, caddisfly larvae, and scud populations, and increases in
bloodworms and annelid populations, were noted downstream from a large agricultural
drain in the Klamath River.
68-69:02K-008
LABORATORY AND FIELD TESTS OF POND SEALING BY CHEMICAL TREATMENT,
Sewell, John I.
Tennessee University, Knoxville, Dept of Agricultural Engineering.
Agricultural Experiment Station Bulletin No. 437, March 1968.  14 p, 4 fig, 5 tab, 4
ref.

Descriptors:  *Seepage, *Permeability,  *Reservoir leakage, *Reservoirs, *Darcy's Law,
Lagoons, Ponds, Farm ponds, Water holes.
Identifiers:  *Pond sealing.

Over 500 permeability tests with 8 soil-dispersing chemicals were conducted on 9 Ten-
nessee soil types.  Sodium pyrophosphate treatments at 2 and sodium carbonate (soda
ash) at 5 tons per acre were the most successful.  These treatments costing approxi-
mately $375 per acre for chemicals reduced the permeability of the 9 soils from 1/10
to 1/100 of the permeability of identical but untreated samples.  Laboratory test
results suggest that at least 1 ft. of well-compacted, relatively impervious seal
blanket over porous areas of pond floors is necessary to prevent rupture of the seal
blanket under 10-ft. heads.  Nine seriously leaking ponds were treated according to
the best procedures developed in the laboratory.  Eight of these treated ponds held
well; and between January 1 and November 15, 1967, the mean ratio of minimum to maxi-
mum pond depths was 0.74.  One pond developed serious leaks which were successfully
repaired to a pond depth of 6 feet.  The field tests substantiated the laboratory
tests in that chemical treatments can,  for certain situations, be effective in re-
ducing reservoir seepage.
68-69:02K-009
STEADY STATE STUDIES OF NITRIFICATION IN SOIL:  THEORETICAL CONSIDERATIONS,
McLaren, Douglas A.
California University, Berkeley, Dept of Soils and Plant Nutrition.
Soil Science Society of America Proceedings, Vol. 33, No. 2, p 273-276, March-April
1969.  1 fig, 17 ref.

Descriptors:  *Equilibriurr., *Nitrif icatior.,  *Soil chemistry, *Theoretical analysis,
Nitrogen cycle, Nitrates, Nitrites, Ammonium.
Identifiers:  Miscible displacement, dynamics.

                                      83

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 The author states that since,  in nature,  ammonia  produced  by  microbial  action or
 added as fertilizer is subjected to downward translocation;  therefore, continuous
 flow laboratory columns would  be more nearly  representative of  field conditions than
 reperfusion methods.   Equations are set up  for  consecutive  reactions in an  idealized
 soil column and solved for  concentrations of  metabolites as functions of  time and
 depth within the column under  steady state  conditions.  The reactions of  ammonium  ion
 to  nitrite ion to nitrate  ion  were so expressed for  columns with maximum  numbers of
 nitrifying organisms.
 68-69:02K-010
 INTERACTION  OF  PESTICIDES  WITH NATURAL  ORGANIC MATERIAL,
 Wershaw,  R.  L.,  Burcar,  P.  J.,  and  Goldberg,  M.  C.
 Geological Survey, Denver,  Colorado.
 Environmental Science  ana  Technology, Vol.  3, No.  3,  p  271-273, March  1969.   3 fig,
 1  tab,  9  ref.

              *Pesticide kinetics,  *Sorption, *Solubility,  *Humic acids, DDT, 2, 4,
              ,  Persistence,  Pesticide residues,  Soil, Soil  chemical properties
              Pesticide  solubi1ization.

 Sodium  humate solubilizes  DDT  and humic  acid  strongly sorbs  2, 4, 5-T.  The solubil-
 ity of  DDT in 0.5% sodium  humate solution is  at  least 20  times its solubility in pure
 water.  Solutions of 2,  4,  5-T  of  .0000121  g/ml  and 0.1 N NaCl were mixed with humic
 acid.   Adsorption data are  shown graphically.  Ion exchange  may play a part in this
 sorption.
 63-69:02K-011
 THEORETICAL CONSIDERATION OF THE CALCIUM SULFATE-BICARBONATE-CARBONATE INTERRELATION
 IN  SOIL  SOLUTION,
 Nakayama, F. S.
 Agricultural Research  Service,  Phoenix, Arizona.
 Soil Science Society of America Proceedings, Vol. 33, No. 5, p 663-672, September -
 October  1969.   5 fig,  2 tab, 13 ref.

 Descriptors:  *Thermodynamics,  *Water chemistry, *Bicarbonates, *Carbonates, *Sul-
 fat.es, Water qualitv,  Aqueous solutions, Soil physical properties, Soil chemical prop-
 erties,  Gypsun, Reclamation, Soil water, Ions, Soil moisture, Acidity, Chemical po-
 tential.
 Identifiers:  *Ion-pairs distributions, Activity, Activity coefficients.

 The probable distributions of the ion-pairs calcium-sulfate and calcium-carbonate and
 complex  calciu:a bicarbonate ion in solution are discussed thermodynamically and
 graphically in  terms of suifate, carbonate, bicarbonate, and hydrogen ion activities.
 In  alkali media where  the carbonate form predominates, the calcium-carbonate species
 will dominate Uie caiciur.'-sulfate and calcium-bicarbonate forms, and is a significant
 part of  the total calcium in solution.  The complexed and undissociated forms of Ca
 represent a significant portion of the total Ca in solution at equilibrium.  Reclama-
 tion projects involving the improvement of soil physical and chemical properties us-
 ing gypsum and other Ca sources require an understanding of these relationships.
63-69 -.02K-012
SULPHATE REDUCTION IN WATERLOGGED SOILS,
Bloomfield, C.
Rothamsted Experimental Station, Harpenden  (England).
Journal of Soil Science, Vol. 20, No. 1 p 207-221, March 1969.  8 fig, 3 tab, 35 ref.

Descriptors:  *Saturated soils, *Sulfates, *Water chemistry, *Biodegradation, *Sul-
fur bacteria, Anaerobic bacteria, Sulfides, Hydrogen sulfide, Organic matter.
Identifiers:  Sulfate reduction, Desulfovibrio.

To study the factors that influence the release of free hydrogen sulfide, flooded
soils were incubated with plant material and either sodium sulphate or elemental
sulfur.  Residual sulphate, FeS and hydrogen sulfide were measured throughout the
reaction.  Less free hydrogen sulfide was evolved from a periodically waterlogged
soil than from a well-drained soil comparable HCi- and dithionite-soluble Fe content.
With a readily soluble synthetic iron oxide as the source Fe, a slight excess of Fe


                                      84

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over the sulfate-equivalent sufficed to prevent loss of hydrogen sulfide.  The native
organic matter in the well-drained Rotharasted top-soil seemed to have no effect in
promoting loss of hydrogen sulfide, but the FeS :  hydrogen sulfide ratio was strongly
influenced by the nature of the plant material used as the source of energy.   With
either sodium sulfate or S, considerably more free hydrogen sulfide was evolved with
lucerne than with rice blade.  With S, the pH of the incubated mixtures was close to
that of the nominally S-free system, whereas with sodium sulfate the mixture became
quite alkaline.  More free hydrogen sulfide was evolved under the more alkaline con-
ditions obtained with sodium sulfate, which suggests that it is the initial mobiliza-
tion of Fe that governs the distribution of the reduced S, rather than the pH-solu-
bility relations of FeS.  An oxidized surface layer is very effective in retaining
sulphur in the soil.
68-69:02K-013
THE MEASUREMENT AND MECHANISM OF ION DIFFUSION IN SOILS,
Vaidyanathan, L. B., Drew, M. C., and Nye, P. H.
Oxford University, Soil Science Laboratory.
Journal of Soil Science, Vol. 19, No. 1, p 94-107, 1968.  8 fig, 1 tab, 12 ref.

Descriptors:  *Diffusion, Potassium, Moisture content, Nutrients, *Approximation
me thod.
Identifiers:  Impedance factor, Hydrogen resin paper.

Integral diffusion coefficients for K in two contrasting soils, containing different
levels of exchangeable K, are calculated from measurements of diffusive flux to a
hydrogen resin paper.  The diffusion coefficients are larger, the higher the exchange-
able K level or moisture content.  Diffusive flux of K in these soils can be account-
ed for entirely by diffusion through the soil solution in the pores.  Impedance fac-
tors calculated compare satisfactorily with values for similar soils reported by
other workers.  The concentration dependence of the diffusion coefficient is shown to
be causally related to the nature of the sorption isotherm.  A method for estimating
the differential diffusion coefficient at any concentration is described.  It can
also be calculated from the slope of the sorption isotherm at the chosen concentra-
tion, if the value of the impedance factor at the relevant moisture content is known
and if diffusion other than through solution only is negligible.
68-69:02K-014
A COMPARATIVE STUDY OF NITRIFICATION IN SOILS FROM ARID AND SEMI-ARID AREAS OF ISRAEL,
Etinger-Tulczynska, R.
Bacteriology Laboratory, Rehovot, Israel.
Journal of Soil Science, Vol. 20, No. 2, p 307-317, 1969.  10 tab, 16 ref.

Descriptors:  *Nitrification, *Arid lands, *Subhumid climates, Nitrogen, Sodium com-
pounds, Ammonium compounds, Potassium compounds.
Identifiers:  Israel, Chloromycetin, Nitrosomonas-Nitrobacter.

The influence of different factors on the nitrification of an added ammonium salt and
inherent soil-N in soils from arid and semi-arid areas of Israel was investigated.
Nitrification of ammonium-N proceeded rapidly at 28""C but was inhibited partially or
completely in soils incubated at 37-40°C.  In contrast, nitrate formation from inher-
ent soil-N proceeded better at 37-40cC than at 28CC.  Bacteriological examination
showed that a temperature of 37-40^C had an injurious effect on the population of
nitrifiers, especially the nitrate-forming bacteria.  Nitrification by the Nitrosom-
onas-Nitrobacter group in culture media was also markedly inhibited at 37°C as com-
pared with that at 28CC.  Chloromycetin at a concentration of 25 mg per 100 g soil,
and potassium chlorate at a concentration of 10  M, suppressed the formation of nit-
rate from ammonium-N more strongly than that from inherent soil-N.  Marked differen-
ces in the two nitrification processes in the soils investigated provided good evi-
dence that the greater part of nitrate originating from soil-N is produced by some
process other than that which is responsible for nitrification of ammonium-N.
68-69:02K-015
PHOSPHORUS ADSORPTION SITES IN SOILS,
Harter,  R. D.
Connecticut Agricultural Experimental Station, New Haven.
Soil Science Society of American Proceedings, Vol. 33, No. 4, p 630-632, July-August
1969.  3 tab, 10 ref.

                                      85

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 Descriptors:   *Phosphorus,  *Soil properties,  Organic  matter, Aluminum,  Iron.
 Identifiers:   *Extractable  phosphorus.

 Regression analysis of phosphorus adsorption  as  a  function  of  five  soil characteris-
 tics indicates that organic matter is  important  in the  initial bonding of phosphorus
 by soils.   It is,  therefore,  proposed  that  phosphorus is  initially  bonded to anion
 exchange sites on  organic matter, and  subsequently transformed into less soluble iron
 and aluminum  phosphates.
 68-69.-02K-016
 LYSIMETER STUDIES  ON TRACER NITROGEN IN FOREST  SOIL:   I. NITROGEN LOSSES BY LEACHING
 AND  VOLATILIZATION AFTER ADDITION  OF UREA  -N15,
 Overrein,  L. N.
 Norwegian Forest Research Institute,  Vollebekk, Norway.
 Soil Science,  Vol.  106,  No.  4,  p 280-290,  1968.   4  fig,  2  tab, 17 ref.

 Descriptors:   *Lysimeter,  Nitrogen,  Leaching Urea,  Fertilizer, Physical properties,
 Forest  soils.
 Identifiers:   Gas-sampling system.

 A  description  is presented of a lysimeter  system  in combination with a gas-sampling
 apparatus,  developed to  study nitrogen transformations in  40 cm deep soil profiles
 with a  natural stratification.  This  investigation  deals with experiments on urea-N-'-
 at rates  from  100  to 1000  kg N/ha  added to raw  humus in  lysimeters exposed to natural
 environmental  conditions in  a boreal  forest.  The analytical procedure includes de-
 termination of N2<  NO, N20,  N02, and  the isotope-ratio analysis of the respective gas-
 eous components by  analytical-preparative  gas chromatography in combination with
 scanning  mass  spectrometry.  The 12-week experimental period had a total precipita-
 tion of about  370  mm.  During this time, the accumulated loss of nitrogen by leaching
 in the  forest  soil  was slight,  or  even negative, at urea application rates less than
 250  kg N/ha.   The  1000 kg  urea-N/ha  treatment was followed by a leaching loss equal
 to 5 percent of the added  fertilizer-N.  The retention of urea-N reported is mainly
 attributed  to  processes  involving  the formation of  non-leachable complexes of fertil-
 izer-N and  organic  matter  in raw humus.  Urea added to raw humus induced losses of
 original  humus nitrogen  by leaching  and volatilization.  The higest total accumul-
 ated loss of ammonia was equal  to  3.5 percent of added urea-N.
68-69:02K-017
NITROGEN, PHOSPHORUS, AND POTASSIUM  INFLUENCE YIELD AND CHEMICAL COMPOSITION OF
BLUEJOINT FORAGE,
Laughlin, W. M.
Agricultural Research Service, Palmer, Alaska, Crops Research Division.
Agronomy Journal, Vol. 61, No. 6, p  961-964, November-December 1969.  2 fig, 8 tab,
18 ref.

Descriptors:  *Wheatgrasses, Alaska, Subarctic, Calcium, *Nitrogen, *Phosphorus,
Boron, *Potassium, Manganese, Copper, Molybdenum, Cobalt, Fertilizers.
Identifiers:  Barium, Alaska.

Field studies were conducted in the Matanuska Valley with bluejoint (Calamagrostic
canadensis)  from 1963-7 with annual applications of three N rates with and without P
and K.  N application increased dry-matter yields, N and Mg content, and N, P, and K
uptake.  N response increased each year when P was used.  N decreased Ca,  Al,  B,
Ba, and Dr concentrations.  P application increased dry-matter yields, stand density,
P, Ca, Mg, K, and Mn contents, and N, P, K, Ca, and Mg uptake and decreased the N
percentage.   K application increased dry-matter yield and K and Cu content only when
P was used.   K depressed Ca, Mg, Ba, B, Sr, and Zn contents.  Native bluejoint re-
sponds favorably to N and K fertilization when adequate P is used.
68-69:02K-018
2, 4-D DIFFUSION IN SATURATED SOILS:  A MATHEMATICAL THEORY,
Lindstrom, F. T., Boersma, L., and Gardiner, H.
Oregon State University, Corvallis.
Soil Science, Vol. 106, No. 2, p 107-113, 1968.  3 fig, 2 tab, 6 ref.

Descriptors:  ^Diffusion, *Saturated soils, *Chemicals, Clays, Organic matter.  Herb-
icides, Soil water.

                                       86

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Identifiers:  2,4-D acid, pH.

A simple theory for describing the movement of chemicals in soil by diffusion is pre-
sented.  An experimental procedure for measuring the value of the diffusion coeffi-
cient of the chemical and the retentive ability of the soil is described.  The general
applicability of this procedure is illustrated by determining coefficients for 2,4-D
acid using nine different soils of varying pH, clay content, organic matter, and ion
exchange capacity.
68-69:02K-019
STUDIES ON EXCHANGE OF SODIUM FROM SOILS BY LEACHING WITH CALCIUM SULFATE,
Chaudhry, G. H., and Warkentin, B. P.
McGill University, Quebec, Canada.
Soil Science, Vol. 105, No. 3, p 190-197, 1968.  4 fig, 4 tab, 17 ref.

Descriptors:  *Sodium, *Leaching, *Calcium sulfate, Clays, Magnesium, Saturation.
Identifiers:  Sodium-calcium exchange.

The exchange of sodium from soils and clay minerals was studied by leaching columns
of the materials with calcium sulfate.  The exchangeable sodium percentage was rapidly
reduced to 5 to 10 percent; further reductions were slow and required large amounts
of leaching solution.  After sodium no longer appeared in the leachate, from 3 to 6
percent exchangeable sodium remained on the clay.  Complete replacement of sodium by
leaching was not possible.  Replacement of magnesium did not begin until the rapid
exchange of sodium was completed.  Differences in solute mixing among the different
clays were more important than differences in sodium-calcium exchange constants, re-
sulting in an efficiency of replacement in the order:  attapulgite > kaolinite >
halloysite » illite > montmorillonite.  The initial rapid exchange of sodium led to
a uniform concentration of sodium remaining where less than symmetry amounts of cal-
cium were used.
68-69:02K-020
FIXATION OF ATMOSPHERIC NITROGEN BY NON-LEGUMES IN WET MOUNTAIN MEADOWS,
Porter, L. K., and Grable, A. R.
Agricultural Research Service, Fort Collins, Colorado.
Agronomy Journal, Vol. 61, No. 3, p 521-523, May-June 1969.  1 fig, 5 tab, 8 ref.

Descriptors:  *Nitrogen, *Irrigation, Organic matter, Legumes, *Grasslands, Water
tables, Microorganisms.
Identifiers:  *Moutain meadows, Nonlegumes.

Mountain soils subjected to excessive irrigation and high water tables accumulate
organic matter in sod mats.  Meadow soils often contain two or three times more N
than equal areas of adjacent dry soils.  Symbiotic nitrogen fixation by legumes is
one possible source of N for sod mat formation.  Fixation of N2 by free-living organ-
isms has also been postulated and was verified by the laboratory studies reported
here.  Nitrogen fixation by sod mats containing no legumes was determined at 18°C in
atmospheres containing N2  -  Both photosynthetic and nonphotosynthetic organisms
appeared to fix N2.  In 10 days, mats in the dark fixed from 0.76 to 1.90 kg KT2~-'-
and illuminated mats fixed from 3.72 to 6.86 kg N ha"-'-.
                                      37

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                                     SECTION IX


                     WATER SUPPLY AUGMENTATION AND CONSERVATION

                         SALINE WATER CONVERSION  (Group 03A)


68-69:03A-001
ECONOMIC FRAMEWORK FOR SALINITY CONTROL PROJECTS,
Coffey, Philip J.,  and Ortolano, Leonard.
Harvard University, Cambridge, Massachusetts.
Journal of the American Water Works Association, Vol. 61, No. 5, p 237-241, May 1969.
2 fig, 2 tab, 16 ref.

Descriptors:  *Salinity, *Water pollution control, *Economic justificatinn, Cost-
benefit analysis, Mathematical models, Marginal benefits, Marginal costs, Dissolved
solids, Water users, River flow, Optimum development plans, Water management (Ap-
plied) .
Identifiers:  Differential equations, Graphical methods.

A systematic approach for finding the optimal level and type of salinity control on a
river was presented, and a hypothetical example demonstrated its use.  The objective
was to determine the minimum total pollution cost, which was the sum of upstream con-
trol costs  (a decreasing function of downstream residual salinity), and downstream
users costs  (an increasing function of salinity).  Differential equations of cost as
a function of total dissolved solids were derived and solved.  The necessary first
and second order conditions for cost minimization or benefit maximization were ob-
tained.  A graphical method was presented which extrapolated between four possible
treatment levels.  The method can be applied in situations where the level of water
use is static.
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                                      SECTION X


                     WATER SUPPLY AUGMENTATION AND CONSERVATION

                         WATER YIELD IMPROVEMENT (Group 03B)


68-69:038-001
LIQUID-LIMIT DETERMINATION FOR INDICATING EFFECTIVENESS OF CHEMICALS IN POND SEALING,
Sewell, J. I., and Mote, C. R.
Tennessee University, Knoxville, Dept of Agricultural Engineering.
Transactions American Society of Agricultural Engineers, Vol. 12, No. 5, p 611-613,
September-October 1969.  6 fig, 3 tab, 6 ref.

Descriptors:  Ponds, *Soil sealants. Seepage, *Permeability, Dispersing agents,
*Liquid limits, Reservoirs, Plasticity index, Reservoir leakage, Soils, Soil proper-
ties, Soil mechanics.
Identifiers:  Soil pasticity, *Seepage control, Permeability tests, Canal sealants,
Sodium carbonate, Sodium phosphates, *Chemical sealants.

Rapid and accurate methods are needed for selecting chemical pond sealers and deter-
mining application rates for a given soil.  A probably satisfactory method involves
running standard constant-head permeability tests on treated soil samples, but con-
siderable laboratory equipment may be required and at least 30 days delay to reach
steady-state permeameter discharge rates may be necessary.  A quicker and simpler
method for evaluating chemical treatment of some soils would be determining the dec-
rease in liquid-limit from chemical treatment.  Chemical dispersing agents used as
pond sealers break soil aggregates into finer particles, reduce soil permeability,
and increase fluidity of the soil-water system; and determination of liquid-limit is
a method for measuring changes in the fluidity of the soil-water system.  Laboratory
tests made on 7 Tennessee soils treated with sodium carbonate and sodium pyrophos-
phate evaluated the accuracy of liquid-limit as a measurement of permeability.  Res-
ults showed liquid-limit correlation with permeability for 5 plastic soils, and no
correlations for a soil of plasticity and a soil of low plasticity.
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                                     SECTION XI


                     WATER SUPPLY AUGMENTATION AND CONSERVATION

                    USE OF WATER OF IMPAIRED QUALITY  (Group 03C)


68-69:03C-001
SOME EFFECTS OF HIGH SALINITY ON GERMINATION AND EMERGENCE OF BARLEY,
Donovan, T. J., and Day, A. D.
Arizona Agricultural Experiment Station, Tucson.
Agronomy Journal, Vol. 61, No. 2, p 236-238, March-April 1969.  3 tab, 9 ref.

Descriptors:  *Salinity, *Barley, *Plant growth, *Salt tolerance, *Germination, Arid
lands. Soil-water-plant relationships, Saline soils, Seeds, Plant physiology, Ariz-
ona, Saline water.
Identifiers:  Emergence (Seedlings).

Salinity frequently limits crop production in arid and semiarid agricultural regions.
Thirty-nine barley varieties and lines were germinated in distilled water and in a
water and sandy loam culture salinized to various concentrations.  Most commercial
varieties of barley had lower germination rates than did California Mariout and sev-
eral saline tolerant strains developed by the USDA.  Emergence in salinized soils
was comparable to germination in water solutions.  At moderate salinity levels most
of the barleys performed well.  At high salinity only the California Mariout and the
salt tolerant strains were satisfactory.  All the barleys were delayed in emergence
in the highly saline media.  In saline areas, tolerant barleys should be used, or if
irrigation practices permit maintenance of low salinity during germination, higher
salinity at later stages may not greatly affect yields .  Laboratory methods are use-
ful in screening barley varieties but should be supplemented by field trials.
68-69:03C-002
QUALITY OF WATERS FROM PLAYAS ON THE SOUTHERN HIGH PLAINS,
Lotspeich, Frederick B., Hauser,  Victor L, and Lehman, Oliver R.
Agricultural Research Service, Bushland, Texas.
Water Resources Research, Vol. 5, Mo.  1, D 48-58, February 1969.  8 fig, 5 tab, 16
ref.

Descriptors:  *Water quality, *Water chemistry, *Playas, * Surface runoff, *Texas,
Runoff, Water storage, Groundwater, Aquifers, Salts, Nitrates, Hydrogen ion concen-
tration, Electrical conductance. Watersheds (Basins), Dissolved solids. Sodium.

It is estimated that 2.5 to 3.0 million acre-feet of surface runoff accumulate an-
nually in the thousands of playas that dot the southern High Plains.  Most of this
water is wasted by evaporation, but much of it could be conserved by storage in the
aquifer.  However, past lack of knowledge about its quality has impeded progress.
A study was conducted to determine the quality of water from 13 playas in an area
extending about 100 miles from northeast to southwest and covering two major soil
types.   The change in water quality with time was also determined.  Playa water con-
tained less salts than groundwater and was of excellent quality for irrigation.  Nit-
rate contents were less than 1.0 mg/liter in nearly all playas.  Almost no nitrogen
applied as fertilizer was washed into playas by runoff water.  High and variable
amounts of suspended solids contained in playa waters were substantially reduced by
settling in deep reservoirs protected from wind and wave action.
68-69-.03C-003
SODIUM HAZARD OF IRRIGATION WATERS AS INFLUENCED BY LEACHING FRACTION AND BY PRECIP-
ITATION OR SOLUTION OF CALCIUM CARBONATE,
Bower,  C. A., Ogata, G., and Tucker, J. M.
Agricultural Research Service, Riverside, California.
Soil Science, Vol. 106, No. 1, p 29-34, July 1968.  4 fig, 5 tab.

Descriptors:  *Sodium, *Irrigation water, *Leaching, *Chemical precipitation, *Cal-
cium carbonate, Hydrogen ion concentration, Lysimeters, Alfalfa, Salinity, Loam,
Adsorption, Cation exchange, Drainage water, Calcium, Magnesium.
Identifiers:  Leaching fraction, Steady state values.
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 Calcareous  Pachappa  sandy loam in  lysimeters  growing  alfalfa was  irrigated with six
 waters  having  variable  Na/(Ca  + Mg)  and  HC03/(C1=S04)  ratios at leaching  fractions
 of  .1,  .2,  .3,  and  .4,  until the sodium  adsorption ratio of the drainage  water be-
 came  constant.   Increased leaching repressed  precipitation of CaC03 from  the waters
 and enhanced solution of  CaC03 from the  soil.  At any leaching fraction,  the amount
 and fraction of applied HC03 that  precipitated as CaC03 from the  water or the amount
 of CaCO3  that  dissolved from the soil  was highly related to a calculated  pH value of
 the water which was  dependent  primarily  upon  the Ca,  Mg, and HC03 concentrations of
 the water.  When the sodium-adsorption ratio  of the drainage waters from  the lysim-
 eters had become constant,  the salt and  exchangeable  Na that had  accumulated in the
 soil  increased with  depth.
 68-69:030-004
 PEANUT RESPONSE TO UNIFORM AND NON-UNIFORM SOIL SALINITY,
 Shalhevet, J., Reiniger,  P., and  Shimshi, D.
 National and Univ. Inst.  of Agriculture, Rehovoth  (Israel), Volcani Inst. of Agricul-
 ture Research.
 Agronomy Journal, Vol.  61, No. 3, p  384-387, May-June 1969.  3 fig, 3 tab, 5 ref.

 Descriptors:  *Peanuts, *Saline soils,  *Plant growth, *Crop response, *Crop produc-
 tion, Arid lands, Irrigation, Evapotranspiration, Adsorption, Germination, Growth
 stages, Seeds, Plant physiology,  Salinity, Salt tolerance, Soil profiles.
 Identifiers:  *Soil salinity, *Water uptake, Israel.

 Peanuts grown in artificially salinized plots showed a 50 percent yield reduction at
 an EC sub e of 4.7 mmhos/cm and a 20 percent reduction at an EC sub e of 3.8 mmhos/
 cm.  As long as there was equal mean soil salinity, the shape of the soil salinity
 profile did not affect  yield reduction.  As salinity increased, total ET decreased,
 but it would appear that  the reduction  in water uptake resulting from increased soil
 salinity was the consequence of reduced growth, rather than the cause of it.  The de-
 crease in ET efficiency at high salinity levels was due not to transpiration, but to
 evaporation from plots  having an  incomplete plant cover.  Salt tolerance was higher
 during germination than during any subsequent growth stage.  At an EC sub e of 13
 mmhos/cm a 50 per cent  reduction  in germination was obtained.  There was a similar
 50 percent reduction in seedling development at an EC sub e of 7.2 mmhos/cm.
68-69:03C-005
EXPERIMENT IN THE LEACHING OF SALINE LAND IN SOUTHERN KAZAKHSTAN,
Kalinin, Ya. D.
Soviet Hydrology: Selected Papers, Issue No. 2, p 201-209, 1969.  2 fig, 8 tab, 7 ref.
Translated from Hydraulic Engineering and Reclamation (Gidrotekhnika i melioratsiya),
No. 8, p 66-75, 1969.

Descriptors:  *Leaching, *Saline soils, *Land reclamation, *Irrigation, Drainage,
Irrigation effects, Irrigation practices, Salinity, Salt balance, Soil management.
Identifiers:  *USSR, *Kazakhstan.

Saline lands in Kazakhstan were leached for the first time over a large area (1100
hectares) at state farm No. 1, located in the area of the Arys'-Turkestan irrigation
system  (northwestern part of Chimkent Province).  The site of  this irrigation system
is between the gently sloping piedmont plain of the Kara-Tau Ridge and the old allu-
vial plain of the Syr-Dar'ya River.  The elevations of this area are 200-240 m and
the slopes, 0.001-0.006.  The mean annual precipitation is 184-210 mm with a weak
maximum in the winter-spring period.  The mean annual air temperature is 12-12.7 deg
C.  The frost-freeperiod lasts 195 days with a mean daily temperature sum of 4300
deg C.  The average annual relative air humidity is 53% and evaporative power reaches
1500 mm per year.  Prior to leaching, a salt survey was performed.  It was found that
of the total area of the irrigated area, 38.6% was saline, including 29.8% with soil
salinity ranging from 0.7 to 3.0%.  The permissible residual salinity after leaching
was found to be 0.3-0.4% with allowance for the composition of the initial salts.
Leaching removed 145,000 metric tons of salts  (69%), including 29,300 metric tons of
the chloride ion (96%), from the upper meter of the soil, originally containing
211,000 metric tons of salt.
                                      94

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                                     SECTION XII


                     WATER SUPPLY AUGMENTATION AND CONSERVATION

               CONSERVATION IN DOMESTIC AND MUNICIPAL USE (Group 03D)


68-69:030-001
CONSERVATION OF WATER IN AGRICULTURE, INDUSTRY, AND MUNICIPAL USE,
Ackerman, Edward A.
Carnegie Institution of Washington, Washington, D.C.
Water Resources Bulletin, Vol. 4, No. 1, p 3-20, March 1968.  4 fig, 1 tab.

Descriptors:  *Water conservation, Pesticides, Sediments, *Hydrologic cycle, Meteoric
water, Evaporation, Evapotranspiration, Precipitation (Atmospheric), Quality control,
*Water management  (Applied), Decision making, *Agricultural chemicals, Waste dispos-
al, Planning, Social values, Communication, Aesthetics,  Pollutants.
Identifiers:  *Atmospheric reservoir, *Quality conservation, *Water supply, Biosphere,
Development, Urban impact, Recycle.
Factors to be considered in planning research and development are related to water
conservation practices.  Effective conservation lies in recognition by policy leader-
ship of the following:  (1) water problems are not divisible; (2) effective water man-
agement means integrated management; and  (3) future conservation actions must be
based on broad and effective public communication.  A conservation system, including
man and his environment, is described as a variant of the hydrologic cycle.  Main-
tenance of water quality is as important as conserving quantity; pollution control,
as a part of conservation, is being increasingly recognized and attacked in urban and
industrial areas.  The more difficult problem of agricultural pollution by sediment,
leached salts, pesticides, and other sources is receiving more attention.  Objectives
for water quality conservation are presented: (1) the traditional approach which
stresses natural waste disposal functions of streams but does not consider aesthetic
and other values; and  (2) a new approach which proposes that water as a part of the
human environment, like air, should be as clean as we can make it.  Integrated plan-
ning and development is a central objective.
                                      95

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                                    SECTION XIII


                     WATER SUPPLY AUGMENTATION AND CONSERVATION

                       CONSERVATION IN AGRICULTURE (Group 03F)


68-69:03F-001
DESIGN OF AN AUTOMATED SURFACE IRRIGATION SYSTEM WITH REUSE SYSTEM,
Fischbach, Paul E.
Nebraska University, Lincoln.
Paper, American Society of Civil Engineers National Irrigation & Drainage Specialty
Conference, Phoenix, Arizona, p 219-236, November 1968.  10 fig, 7 ref.

Descriptors:  Automatic control, Automation, *Irrigation systems, Field tests, Irri-
gation design, *Water reuse, *Surface irrigation, Hydraulic gates and valves, Land
forms, Slopes, Furrow irrigation, Pumping plants, Furrows, Irrigation, Tensiometers,
Control systems, *Irrigation canals, Gate control.
Identifiers:  Reuse.

Design and component features for an automatic surface irrigation system with provis-
ion for reuse of runoff water are described.  Requirements for the system are: a
supply of water available on demand; an enclosed pipe system designed to carry water
from the source to the point of release for irrigation; a method of sequencing irri-
gation sets; control of the water flowing over the land surface; a runoff collection
and return system; soil moisture sensing devices that sense the need for water to
start and stop the system; and electrical controls.  Land forming, row direction,
furrow stream size, length of run, and application time are discussed.  To test and
evaluate the theories propounded, an automatic surface irrigation system with runoff
water reuse was operated for 3 seasons at the University of Nebraska field laboratory
Mead, Nebraska.  The system is described and results are discussed.
68-69:03F-002
AUTOMATION OF SURFACE IRRIGATION SYSTEMS,
Haise, Howard R., and Kruse, E. Gordon.
Agricultural Research Service, Fort Collins, Colorado.
Proceedings National Irrigation and Drainage Specialty Conference, ASCE, Phoenix,
Arizona, p 175-200, November 13-16, 1968.  13 fig, 9 ref.

Descriptors:  *Surface irrigation, *Turnout gates, *Laterals, Automatic  control,
Water distribution.
Identifiers:  *Fluidic diverters, *Water-powered cylinders, *Center pivot gates,
Float valves.

Two systems for automating surface irrigation are described.  One uses pneumatic
valves remotely controlled by tone telemetry to open and close turnouts at timed
intervals.  The other uses water-powered cylinders activated by float valves to
operate center pivot gates.  Large fluidic diverters have also been evaluated for
irrigation applications.  The automation components can be adapted to furrow, border,
dike, and basin irrigated fields supplied by open ditches or buried pipelines.  Sev-
eral field systems have been installed and evaluated.
68-69:03F-003
A HYDRODYNAMIC DETERMINATION OF CUTBACK STREAM SIZES OR IRRIGATION FURROWS,
Wilke, 0. C., and Smerdon, E. T.
Florida University, Gainesville, Dept of Agricultural Engineering.
American Society of Agricultural Engineers Transactions, Vol. 12, No. 5, p 634-637,
September-October 1969.  11 fig, 10 ref.

Descriptors:  *Hydrodynamics, *Flow, *Furrows, *Furrow irrigation, * Irrigation engin-
eering, Irrigation design. Channels, Streamflow, Runoff, Water management  (Applied),
Equations, Water loss, Infiltration, Mathematical models, Volume, Wetting, Applica-
tion methods.
Identifiers:  *Cutback, *Cutback sizes. Steady state.

In order to avoid runoff losses, the stream should be reduced after the wetting front
nears or reaches the end of the furrow.  Two methods of determining the required cut-
back size are volume balance analysis and numerical integration of the steady state

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 equations  of  motion  for  shallow flow.   These  two  methods were  studied and  graphic
 design  relationships  presented.   Good  field verification of  the volume balance method
 was  achieved,  but  more experimentation should be  conducted.  It would then be poss-
 ible to design an  automated  cutback  system which  could  apply water uniformly without
 runoff  losses.
 68-69:03F-004
 WIND VARIATION AND  SPRINKLER  WATER  DISTRIBUTION,
 Seginer,  I.
 Technion,  Haifa,  Israel,  Dept of Agricultural Engineering.
 Journal of the Irrigation and Drainage Division, American  Society of Civil Engineers,
 Vol. 95,  No.  IR2, p 261-274,  June 1969.   10  fig, 4  tab,  5  ref.

 Descriptors:  *Irrigation,  Sprinkler  irrigation, Wind velocity, Water distribution
 (Applied).

 The superimposed  distribution pattern of  a moving sprinkling lateral is not equal to
 that of a  solid set employing the same sprinklers,  whenever wind variations occur
 between positions of the  lateral.   Variations perpendicular to the lateral have the
 most significant  effect,  resulting  in convergence or divergence of two adjacent pat-
 terns.  The uniformity  coefficient  increases  (improves)  and the mean depth of water
 increases  with increased  convergence.  The effect on the uniformity coefficient is
 more pronounced as  the  spacing between lateral positions increases.  For every wind
 regime there  is an  optimum  direction  of the  laterals for which the overall uniformity
 is highest.
68-69 :03F-005
SAVE THAT WATER,
Patterson, P. M.
Irrigation Age, p 16-19, March 1970.

Descriptors:  *Irrigation practices, *Irrigation, Irrigation design, *Irrigation effi-
ciency, Water delivery, Water distribution  (Applied), *Water reuse, *Irrigation eng-
ineering, Management.
Identifiers:  Texas High Plains, *Tailwater return system.

Tailwater loss and tailwater return systems have been the subject of intensive study
in the Texas High plains for the past several years.  These studies began in 1963
and were conducted by the High Plains Underground Water Conservation District in
Lubbock.  Studies indicated that on the average, 20 percent of the water being pumped
will be lost without a tailwater return system.  Representatives of underground water
conservation districts will design tailwater return system on request of the farmer.
The following information is needed for design:  (1) number of wells contributing to
tailwater;  (2) size of wells;  (3) number of acres irrigated by contributing wells;
(4) slope of the land;  (5) type of soil.  Examples of the costs and benefits of tail-
water systems currently in use in the Texas High Plains area are given.
68-69 :03F-006
THE CLIMATE OF THE COTTON CROP: PHYSICAL CHARACTERISTICS AND MICROCLIMATE RELATION-
SHIPS,
Stanhill, G., and Fuchs, M.
Volcani Institute of Agricultural Research, Rehovoth, Israel.
Agricultural Meteorology, Vol. 5, No. 3, p 183-202, May 1968.  9 fig, 5 tab.

Descriptors:  *Cotton, *Climatic data, *Irrigation effects, Humidity, *Microclima-
tology, Air temperature, Growth stages, Semiarid climates, Energy budget, *Crop res-
oonse, Vapor pressure, Wind velocity, Albedo, Water loss, Hygrometry, Soil tempera-
ture, Anemometers, Solar radiation, Heat.
Identifiers:  *Aerodynamics,  *Energy balance, Israel, Solar elevation, Physical char-
acteristics, Heat storage.

A study of the radiative and aerodynamic characteristics of two irrigated cotton
crops was made in a semi-arid zone of Israel,  Some of the physical characteristics
of the irrigated cotton crop of importance in the modification of the crop microclim-
ate were studied and the relationship between the climate over the crop and that mea-
sured at an adjacent open site were determined.  Air temperature was always less and


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humidity greater at the irrigated crop than over the bare soil.  Results obtained
were compared with those previously reported in the literature for this crop in order
to see to what extent they may be considered as being of general application.  Micro-
climate is a factor of great importance in determining yield and water loss from ag-
ricultural crops.
68-69:03F-007
HANDLING WATER BY COMPUTER,
McMullin, R. J.
Salt River Project, Arizona.
Reclamation Era, Vol. 55, No. 3, p 14-17, August 1969.

Descriptors:  *Water delivery, "Water supply, *Computers, Data processing, * Irrigation
water, Water rights, Irrigation.
Identifiers:  Salt River Project.

A description is given of the computer system used for managing waters supplied in
the Salt River Project.  The two system/360 central processing units at the project
administrative headquarters are connected to 15 remote 1050-type communications ter-
minals.  The teleprocessing network enables employees in the project field offices
to promptly and efficiently fill orders for irrigation water.  The central master
file contains the water  rights for each acre of land, an updated record of each water
account, and an accounts receivable record.  The computer is used to furnish water to
subdivision lots and handle the billings.  The system is also used for billing elec-
tricity accounts.
68-69:03F-008
EFFECT OF IRRIGATION AND CLIPPING ON SEED PRODUCTION AND CHASMOGAMY OF SERICEA GLNO-
TYPES,
Donnelly, E. D., and Patterson, R. M.
Auburn University, Alabama, Dept of Agronomy and Soils.
Agronomy Journal, Vol. 61, No. 4, p 501-502, July-August 1969.  2 tab, 13 ref.

Descriptors:  *Seeds, Irrigation, Agriculture, Forages.
Identifiers:  Cleistogamous, Lespedeza cuneata, Seed yield, Clipping.

Seed yield and proportion of chasmogamous seed as affected by irrigation and clipping
were determined for 18 lines of sericea, Lespedeza cuneata.  Seed yields were in-
creased by irrigation regardless of clipping management; however, irrigation did not
increase the percentage of chasmogamous seed.  Clipping in June drastically reduced
seed yield and percentage of chasmogamous seed.  Irrigation of clipped sericea fur-
ther reduced chasmogamous seed percentage below that of nonirrigated clipped sericea.
Lines reacted differently to irrigation and clipping both as to proportion of seed
types and seed yield.
68-69:03F-009
INFLUENCE OF IRRIGATION INTERVAL AND PLANT DENSITY ON ALFALFA SEED PRODUCTION,
Abu-Shakra, S., Akhtar, M., and Bray, D. W.
Beirut American University, Beirut, Lebanon, Faculty of Agricultural Sciences.
Agronomy Journal, Vol. 61, No. 4, p 569-571, July-August 1969.  1 tab, 6 ref.

Descriptors:  *Irrigation.
Identifiers:  Components of seed yield, Hairy Peruvian plants.

Irrigation applied once every 2 weeks, providing a seasonal total of 25.7 cm of
water, produced the greatest seed yield, as well as an increase in the number of
pods per raceme, number of seeds per pod, and 1,000-seed weight.  Plants irrigated at
3 or 4-week intervals produced the highest number of hard seeds.  The 50 x 50 cm
plant spacing produced well developed alfalfa plants which gave relatively high seed
yields of 80 kg/dunum (1,000 m2) in 1966 and 65 kg/dunum in 1967.  The variety
'Hairy Peruvian ' produced more pods per raceme and more seeds per pod resulting in
greater seed yield than that from the varieties 'African' and 'Chilean. '  The Hairy
Peruvian plants were the shortest of the three varieties grown.
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 68-69:03F-016
 FUTURE  IRRIGATION  DEMAND  IN THE  SUSQUEHANNA BASIN,
 Miller,  Howard.
 Chesapeake  Bay-Susquehanna Rivers  Basins  Project, Susquehanna Field Station.
 American Society of  Civil Engineers  Proceedings, Journal of  the Irrigation and Drain-
 age  Division, Vol. 94,  No. IR4,  Paper No.  6278, p 391-399, December 1968.  2 fig,
 8  tab,  2 ref.

 Descriptors:  *Irrigation, *Forecasting,  *Water utilization, Pennsylvania, New York,
 Low  flow, Droughts,  Water loss,  Water resources, Water supply, Seepage.
 Identifiers:  Susquehanna River  Basin.

 Some years  hence,  during drought years, irrigation probably  will have significant and
 locally  detrimental  effects on the surface water economy of  the Susquehanna Basin,
 that is,  barring changes in water  laws or watershed development projects.  Support
 for  the  theory that  practice of  irrigation will grow comes from an analysis of rain-
 fall frequency and crop production deficiencies in drought years.  From this, average
 annual profit per  acre  can be estimated.  From designs of irrigation systems under a
 range of conditions,  annual costs  per acre can be estimated.  By logic, it can be
 assumed  that crops with the greatest profit potential will be irrigated in the future.
 Tempering the synthetic predictions  with  consideration of current irrigation practice
 and  trends, predictions of future  irrigation withdrawals are made.  Whether irriga-
 tion withdrawals will be significant or detrimental depends  on amounts of streamflow
 available during drought periods and the  frequency of such drought occurrences.
68-69 -.03F-017
VARIABLE ROW SPACING OF  IRRIGATED COTTON AS A MEANS FOR REDUCING PRODUCTION COSTS
AND CONSERVING WATER,
Longenecker, D. E., Thaxton, E. L., Jr., and Lyerly, P. J.
Texas Agricultural Experiment Station, El Paso
Agronomy Journal, Vol. 61, p 101-104, January-February 1969.  3 fig, 3 tab, 10 ref.

Descriptors:  *Irrigation practices, *Water conservation, Irrigation efficiency,
*Cotton, Evaporation control, Crop yield.
Identifiers:  *Variable  row spacing, Skip row effect.

Results of three years '  field studies of a new irrigation cotton row spacing pattern
are reported.  This new  pattern, called Variable Row Spacing  (V.R.S.), consisted of
alternate wide (1.37 m)  and narrow  (0.66 m) rows with furrows only between the 0.66-m
rows.  Purpose of the new pattern was to conserve water and reduce production costs.
Tests on both sloping and level irrigation systems are reported.  The V.R.S. system
was shown to be effective in maintaining yields while simultaneously presenting
opportunity for reducing production costs through application of less water per irri-
gation, reductions in evaporation, more efficient utilization of applied water, more
effective weed control,  and earlier maturity of the crop.  A partial skip-row effect
was believed to be obtained without skipping any rows.  Chief obstacle to adoption
of the new system by growers has been inability of commercial spindle pickers to
harvest the variable row spacing pattern.
68-69 :03F-018
CONSUMPTIVE USE DERIVED FROM EVAPORATION PAN DATA,
Hargreaves, George H.
USAID,  Bogota, Columbia.
American Society of Civil Engineers Proceedings, Journal of the Irrigation and Drain-
age Division, Vol. 94, No. IR1,  Paper Mo. 5863, p 97-105, March 1968.  5 tab, 10 ref.

Descriptors:  *Evapotranspiration,  *Evaporation, *Consumptive use, *Climatic data,
Irrigation programs, Rainfall, Evaporation pans.
Identifiers:  Irrigation requirements, Evapotranspiration calculations.

Evapotranspiration measurements  or computations provide basic information for the
computation of irrigation requirements.  Unfortunately, in underdeveloped or develop-
ing countries both evapotranspiration and weather data are usually of limited avail-
ability and for some proposed project areas nonexistent.  Formulas and methods are
required by engineers working on design and development of irrigation.  These must
permit  the evaluation of needs and  requirements for irrigation with an absolute mini-
mum of  data.  Formulas are given for computing evaporation from climate data.  Ratios
of evapotranspiration to Class A pan evaporation are given for a large number of


                                      102

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crops.  Crops are grouped together or assigned general classifications whenever poss-
ible.  Consumptive use coefficients converting evaporation to evapotranspiration are
given by 10% increments of the crop growing season or vegetative cycle.  A method of
computing utilizable rainfall is presented and a formula is given for converting
evapotranspiration to irrigation requirements.  Irrigation requirements may be com-
puted with several levels of data availability if temperature and rainfall measure-
ments at the disposal of the engineer constitute the minimum of data required.
68-69:03F-019
SURFACE IRRIGATION HYDRAULICS-KINEMATICS,
Hart, William E., Bassett, Day L., and Strelkoff, Theodor
California University, Davis, Dept of Water Science and Engineering.
American Society of Civil Engineers Proceedings, Journal of the Irrigation and Drain-
age Division, Vol. 94, No. IR4, Paper No. 6284, p 419-440, December 1968.  8 fig,
18 ref, 3 append.

Descriptors:  *Surface irrigation, *Infiltration, Storage, Hydraulics, Mathematical
models, Mathematical studies, Unsteady flow, Non-uniform flow, Open channel flow,
Recession curves.
Identifiers:  Irrigation water advance, Irrigation water recession.

The mathematical solutions of surface irrigation flow and infiltration are reviewed.
Their similarities lead to easy classification and simplification.  An approach is
proposed which uses defined shape factors to solve the advance of water, surface
storage, storage depletion, recession, and infiltration during unsteady nonuniform
flow over a porous bed.  True solutions of the mass-conservation equation are ana-
lyzed and compared.  Methods of numerically solving the equations are developed and
discussed.  Solutions are presented as dimensionless advance curves which can be used
for field applications.
68-69:03F-020
SALT BALANCE, IRRIGATION EFFICIENCY, AND DRAINAGE DESIGN,
Bouwer, Herman.
Agricultural Research Service, Phoenix, Arizona.
Journal of the Irrigation and Drainage Division, ASCE,  Vol. 95, No. IR1, Proc.  Paper
No. 6465, p 153-170, March 1969.  4 fig, 3 tab, 27 ref.

Descriptors:  *Salt balance, *Salt tolerance, *Irrigation efficiency, *Leaching,
*Drainage systems, Irrigation water, Root zone. Equations, Water utilization, Water
requirements, Rates of application, Drains, Design, Salts, Crop response, Water
table.
Identifiers:  *Leaching efficiency, Salt concentration.

A simplified procedure was presented to predict how much irrigation water was neces-
sary, in addition to that for evapotranspiration, to maintain salt balance in the
root zone.  The key factor in the procedure was the leaching efficiency, which ap-
peared to range from 0.2 for fine textured soils to 0.6 for coarse textured soils.
Also taken into account were salt tolerance of the crop, salt concentration of the
irrigation water and evapotranspiration.  The procedure accurately predicted known
leaching requirements for salt balance of 3 irrigated regions.  In defining irriga-
tion efficiency, distinction was made between efficiency of water utilization and
efficiency of water application.  In conclusion, it was shown that drainage flow from
the root zone decreased with time after an irrigation and that the water table re-
sponse of a system of parallel drains to this flow could be computed for design of a
drainage system to avoid high water tables.
68-69:03F-021
EFFECTS OF TILLAGE, NO TILLAGE, AND MULCH ON SOIL WATER AMD PLANT GROWTH,
Jones, J. N., Jr., Moody, J. E., and Lillard, J. H.
Agricultural Research Service, Blacksburg, Virginia.
Agronomy Journal, Vol. 61, No. 5, p 719-721, September-October 1969.  2 fig, 3 tab,
7 ref .

Descriptors:  *Soil-water-pIant relationships, *Cultivation, *Mulching, Management,
*Water conservation, Corn, Soil mo-.stare.
Identifiers:  *Zero iillaae, *Kil2a-.; so1, plnr.t ir.y,  *Wo tor ;ise efficiency.

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 Seedbeds  for  corn  (Zea  mays  L.)  were  prepared  by both conventional  tillage and the
 no-tillage method,  each with and witnout  surface mulches.  The mulches consisted of
 killed  grass  sod on the no-tillage  plots  and straw applied on plots with conventional
 tillage.  No-tillage plots without  a  mulch were obtained by removing the killed sod.
 Mulched treatments,  whether  of  undisturbed killed sod on the no-tillage plots, or of
 straw on  conventional plots,  gave the lowest values  for runoff and  the highest values
 for  soil  water content  and yield of corn.  Soil water conserved by  the mulches was
 reflected in  an average grain yield increase of 1,932 kg/ha.  Differences in total
 soil water among treatments  were significant to a depth of 30 cm.  The effect of
 tillage was minor,  but  the data indicate  the value of the killed sod mulch in the no-
 tillage system.
 68-69:03F-022
 IRRIGATING WITH CUT-BACK FURROW  STREAMS,
 Sakkas, J. G. , and  Hart, W. E.
 Thessaloniki University, Greece
 Journal of the Irrigation and Drainage Division, ASCE, Vol. 94, No. IR1, p 91-96,
 March 1968.  2 tab,  3 ref.

 Descriptors:  *Drainage, *Irrigation,*Water distribution  (Applied), Siphons, Furrow
 irrigation.

 Nonuniformity of water distribution in irrigated fields results from unequal intake-
 opportunity times along the run.  The cut-back of  inflow  (as suggested by previous
 workers) allows a large initial  stream and was proposed to eliminate this inequality.
 This requires a variable number  of furrows to be brought under irrigation at the beg-
 inning of successive time intervals.  A mathematical analysis of the variation is
 presented and the results are summarized in tables which give the number of furrows
 started at the beginning of each time interval and being irrigated during each time
 interval.  These tables enable the irrigator to distribute correctly the available
 quantity of water and, when using siphons, to estimate the number of siphons required
68-69:03F-023
THE INFLUENCE OF IRRIGATION, ROW SPACING, PLANT POPULATION, AND INOCULATION ON THE
YIELD OF SOYBEANS IN CANTERBURY,
Dougherty, C. T.
Lincoln College, Canterbury, New Zealand, Plant Science Department.
New Zealand Journal of Agricultural Research, Vol. 12, p 367-380, 1969.  6 tab, 5 ref

Descriptors:  *Irrigation, *Soybeans, *Plant populations, Agronomy, Cultivation,
Soil-water-plant relationships.
Identifiers:  Plant density, Inoculation.

A 25 factorial design was used to evaluate the influence of irrigation, row spacing,
plant density, and inoculation on the growth and yield of Harosoy and Chippewa soy-
beans (Glycine max (L) Merrill) in Canterbury, New Zealand, in 1966-67.  Higher
yields were obtained from soybeans grown in 20 in. rows and at populations of 110,000
plants per acre than from those grown in 40 in. rows and at populations of 60,000
plants per acre.  Irrigation and inoculation did not increase grain yields.
68-69:03F-024
SOIL WATER STORAGE DURING FALLOW IN THE CENTRAL GREAT PLAINS AS INFLUENCED BY TILLAGE
AND HERBICIDE TREATMENTS,
Smika,  D. E., and Wicks, G. A.
Nebraska Agricultural Experiment Station, North Platte, Nebraska
Soil Science Society America  Proceedings, Vol. 32, No. 4, p 591-595, July-August,
1963, 6 tab, 12 ref.

Descriptors:  *Mulching, *Tillage, Herbicide, Wheat moisture availability, Soil water,
Identifiers:  Wheat-fallow rotations.

Soil water storage during the fallow period of winter wheat-sorghum-fallow (Triticum
aestivum and Sorghum Vulgare) and alternate winter wheat-fallow rotations was mea-
sured during three fallow periods.  Storage was greater when herbicides rather than
•jcnventional tillage practices were used as a result of treatments was distributed
throughout -he profile in the 3-year rotation, but the greatest increase occurred in


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the upper 60 cm of soil.  In the 2-year rotation the nearly 14-cm increase in avail-
able water due to treatment was also present in the entire profile, but most of the
storage increase occurred to a depth of 210 cm, with soil water content to a depth of
180 cm being at or near field capacity.

Soil water storage for the total fallow period of the 3-year rotation ranged from
18.6 to 22.3 cm, having corresponding storage efficiencies of 35.4 and 42.4%, for
conventional tillage and complete herbicide treatments, respectively.  Water storage
for the complete fallow period of the 2-year rotation ranged from 18.6 cm with spring
plowing  (bare soil) to 23.8 cm with tillage stubble mulch to 32.5 cm with complete
use of herbicides, and had storage efficiencies of 25.0, 32.0, and 43.7%, respective-
ly.
68-69:03F-025
WATER CONSERVATION OVER WINTER IN THE NORTHERN PLAINS,
Willis, W. 0., and Haas, H. J.
Agricultural Research Service, Mandan, North Dakota
Journal of Soil and Water Conservation, Vol. 24, No. 5, p 184-186, September - Octo-
ber, 1969.  5 fig, 24 ref.

Descriptors:  *Precipitation, Soil moisture, Evaporation, Erosion, Runoff, Corn,
Agriculture, Water conservation.
Identifiers:  No-tillage system.

Data presented show that available soil moisture was always greater in the no-tillage
system at planting.  These differences, although they gradually decreased because of
greater plant demands, continued throughout the growing season.  The killed sod mulch
insulated the soil and thereby suppressed evaporation, which is the primary mode of
soil water loss for 1 to ~Lh months after seedbed preparation.  For the soils represent-
ed and the climatic conditions experienced during this study, the no-tillage system
produced higher corn yields with less runoff, less evaporation, and negligible ero-
sion.  This resulted in more efficient use of water for crop production.  In Virginia
the no-tillage system appears to be exceedingly advantageous.  Steeper slopes in
good grass sods can be planted to corn without fear of erosion due to excessive run-
off.
68-69:03F-026
ROOT DEVELOPMENT AND PHOSPHORUS UPTAKE BY TOMATO PLANTS UNDER CONTROLLED SOIL MOIS-
TURE CONDITIONS,
Thorup, R. M.
Chevron Chemical Company, Fort Madison, Iowa.
Agronomy Journal, Vol. 61, No. 5, p 808-811, September-October, 1969.

Descriptors:  *Root development, *Phosphorus, *Moisture availability, Tomatoes, Root
systems, Soil-water-plant relationships.
Indentifiers:  *Split-root techniques.

The effect of soil moisture tension upon root growth and phosphorus uptake by tomato
plants was studied using a split-root technique.  Root systems were developed in
soil maintained at three different moisture levels--one well below PWP, another
slightly below PWP, and a third within the "available" range.  Root growth was very
restricted at the lowest level of soil moisture--ataining a maximum length of 20 mm.
At the level slightly below PWP, roots grew to a length of 90 mm, with substantial
secondary root development.  Maximum growth was attained at the moisture level main-
tained above PWP.  At this level, roots reached a length of 150 mm and exhibited
extensive secondary branching.  Phosphorus uptake was measure by use of radioactive
P.  At all three moisture levels, phosphorus was taken up by the plants.  A signifi-
cant increase in uptake accompanied each increase in soil moisture.  Moisture was
transferred through the plant root system from zones of low tension to zones of high
tension within the soil.
68-69:03F-027
TRICKLE IRRIGATION - A PROMISING SECOND TOOL FOR A BREAKTHROUGH IN FOOD PRODUCTION IN
TROPICAL, SUBTROPICAL AND DESERT AREAS,
van't Woudt, B. D.
FAO Regional Office, Bangkok, Thailand.
International Commission on Irrigation and Drainage Bulletin, p 88-93, July 1968 -

                                     105

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 January 1969.   2 fig,  1  tab,  8 ref,  1 append.

 Descriptors:   Irrigation,  *Fertilization,  *Irrigation  practices,  Irrigation effici-
 ency,  Soil-water-plant relationship,  *Application  equipment,  *Saline water, Irri-
 gation systems,  Crop response.
 Identifiers:   *Trickle irrigation. Drip  irrigation.

 A method,  developed in Israel, is  discussed,  through which  a  water-fertilizer mix is
 continuously dripped on  the  soil at  the  base  of  a  crop plant  under  field conditions.
 Early  results,  results from  related  work,  and  field observations  show that this
 method may produce unexpectedly high yields,  allow water of high  salinity to be used,
 reduce drainage  problems and  permit  complete  automatization under field conditions in
 such a way that  water  and  fertilizer  applications  completely  cover  but do not exceed
 plant  needs.   Cost of  installation may vary from US$1,000 to  $3,000  per hectare, but
 results may pay  for this investment  within a  short time.  Further development work
 and the need for a start with a moderate research  program under south and east Asian
 conditions are discussed.
 68-69:03F-028
 SIMULATION  OF  WIND  EFFECTS ON  SPRINKLER  PERFORMANCE,
 Allison,  S. V.,  and Hesse, V.  L.
 Litton  International Development  Corporation, Athens, Greece.
 Journal of  the  Irrigation and  Drainage Division, ASCE, Vol. 95, No. IR4, p 537-550,
 December  1969.   9 fig, 12 ref.

 Descriptors:   *Irrigation, *Irrigation efficiency, *Sprinkler irrigation. Computers,
 Model studies,  Wind velocity,  Wind pressure.

 A brief review  of the literature  relating  to wind effects on sprinkler performance is
 followed  by presentation of a  method by  which system performance was simulated under
 winds varying in both speed and direction.  This approach will permit the results of
 sprinkler tests performed anywhere in the  world to be transferred to other locations
 for which adequate  wind data exist.  Relationships between uniformity and efficiency
 of irrigation are presented.   The recommendation of sprinkler manufacturers and pre-
 vious researchers,  to the effect  that the  solution to the wind problem is simply to
 reduce  spacings, is confirmed.
68-69:03F-029
PLASTIC PIPE AND WATER QUALITY,
Farish, C. A.
National Sanitation Foundation, Ann Arbor, Michigan.
Journal of American Water Works Association, Vol. 61, No. 9, p 480-482, September,
1969.

Descriptors:  *Water quality, *Plastic pipes, Public health, Water pollution, Quality
control.
Identifiers:  *NSF Plastic standards.

There are several grades of plastics pipe available.  Water works officials should
insist upon such products meeting public health standards and sound engineering and
physical standards before they use plastics for potable water.  The plastics industry
is growing rapidly and new materials are being developed and will continue to be de-
veloped.  Old compounds are being modified to improve their properties.  Compounds
which are safe and suitable for hot water applications are becoming available; this
could lead to a broader acceptance of plastics piping in general water distribution
and expanded household applications.  The role of the National Sanitation Foundation
as an objective third party will be to continue its efforts in providing unbiased
certification of those plastics which do not adversely affect water quality.  The
"NSF" seal signifies the product is nontoxic, will not adversely affect the taste,
odor, or appearance of the standards to which it is produced and identified.  Plastic
pipe that has been proven through years of research and testing as public health safe
for potable water use will not adversely affect water quality.
                                      106

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68-69:03F-030
IRRIGATION TIMING AND AMOUNTS,
Linacre, E. T., and Till, M. R.
Macquarie University, N.S.W., Australia, School of Earth Sciences.
The Journal of the Australian Institute of Agricultural Science,  p 175-189,  September
1969.

Descriptors:  *Irrigation, Irrigation practices, Supplemental irrigation,  *Evapotrans-
piration, Leaching, Plant growth, Plant physiology, Soil-water-plant relationships,
Crop response, Infiltration, *Timing, *Water requirements, *Irrigation programs,
*Tensiometers, *Atmometers, *Evaporation pans.
Identifiers:  Sorption blocks, Australia.

This review deals with determining when irrigation is due, particularly by the use of
soil-moisture tension meters or sorption blocks, or by water budgeting.  Several ap-
proximations are given for determining soil moisture deficits to be used in a water
budget.  Crop evaporation estimates were made from measurements with an evaporimeter
of atmometer, or from some formula such as Penman's.  Brief accounts were given of
advisory schemes, operated by central agencies in various parts of the world to aid
the farmer in planning irrigation timing and amounts.
                                     107

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                                      SECTION XIV


                        WATER QUANTITY MANAGEMENT AND CONTROL

                     CONTROL OF WATER ON THE SURFACE (Group 04A)


68-69:04A-001
DESIGN OF RECIRCULATING IRRIGATION SYSTEMS,
Bondurant, J. A.
Agricultural Research Service, Kimberly, Idaho.
American Society of Agricultural Engineers, Transactions, Vol. 12, No.  2,  p 195-198,
201, 1969.  6 fig, 3 ref.
(See 68-69:02E-002)
68-69:04A-002
A STUDY OF THE SPECIFIC YIELD IN LAND-DRAINAGE SITUATIONS,
Dos Santos, A. G., Jr., and Youngs, E. G.
Cambridge University (England), School of Agriculture.
Journal of Hydrology, Vol. 8, No. 1, p 59-81, May 1969.  11 fig, 24 ref.

Descriptors:  *Specific yield, *Soil water, *Drainage, Gravitational water, Porosity,
Permeability, Specific retention,  Water storage, Percolation, Infiltration,  Aqui-
fers.
Identifiers:  Soil air content.

From the definition of the specific yield in an unconfined aquifer, it is shown that
the true specific yield is a function of the horizontal position and time and may be
obtained from the measurements of localized fluxes and localized water-table  move-
ments.  With the assumption of vertical flow above the water table, the specific
yield is derived as the sum of the air content at the surface and the ratio of the
rate of change of the volume of water held in the moisture profile above the  water
table to the rate of rise or fall of the water table.  Since the latter ratio can be
small in certain circumstances, the air content at the surface by itself is often a
fair approximation to the specific yield.  Results of measurements of all the specif-
ic yields, obtained in non-steady state drainage experiments using a completely per-
meable drain installation and a plastic drain installation in a hydraulic model sand
tank, are presented.  With the use of a virtual specific yield given by the air con-
tent at the surface in the midplane position between drain lines, calculated  assum-
ing steady state conditions with a stationary water table height and drain discharge
for a given drain installation, rise and decay curves for the water table are calcul-
ated and compared with experiment, and fair agreement found.
68-69:04A-003
PREDICTING FIELD DISTRIBUTIONS OF SPRINKLER SYSTEMS,
Branscheid, Volker 0., and Hart, William E.
California University, Davis, Dept of Water Science and Engineering.
American Society of Agricultural Engineers Transactions, Vol. 11, No. 6, p 801-803,
808, November-December 1968.  2 fig, 2 tab, 5 ref.

Descriptors:  *Sprinkler irrigation, *Distribution patterns, *Forecasting, Irriga-
tion systems, *Water distribution (Applied), Distribution systems. Irrigation design,
Irrigation efficiency, Spatial distribution, Laterals, Uniformity coefficient, Winds,
Wind velocity.
Identifiers:  Juxtapositioning.

Distribution of water over a field by sprinkler irrigation is an important aspect of
system design and should therefore be known in advance.  An approach was given for
prediction of field distributions from single-sprinkler patterns.  The theoretical
method takes into consideration actual location of sprinklers in the field at the
time of their operation.  A single sprinkler and a lateral line of 13 equally spaced
sprinklers were operated independently of one another at a test site.  In order that
their climatic conditions would be similar, both installations were run at the same
time.  The HSPA uniformity coefficient was used as a measure of uniformity.  Lateral
line sprinkler patterns, when combined, gave assumed field distribution.  Single
sprinkler data, when juxtaposed and overlapped, predicted field distribution as
                                     109

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 indicated by the uniformity coefficient.   Results show that the juxtapositioning pro-
 cedure is a valid one.
 68-69:04A-004
 SALT PENETRATION TECHNIQUE FOR SEEPAGE MEASUREMENT,
 Bouwer, Herman, and Rice,  R.  C.
 Agricultural Research Service, Phoenix, Arizona.
 American Society of Civil  Engineers Proceedings,  Journal  of  the  Irrigation and Drain-
 age Division, Vol.  94,  No. IR4, Paper No.  6304,  p 481-492, December  1968.  7  fig,
 2 tab,  2 ref.

 Descriptors:  *Seepage,  *Infiltration..  *0pen channel  flow, *Tracers,  *0n-site tests,
 Laboratory tests. Reservoirs,  Canals, Irrigation.
 Identifiers:  Salt  penetration, Seepage tracers.

 Seepage rates in open channels or reservoirs are  determined  from the  rate of  salt
 penetration into the bottom material.  A portion  of the bottom is covered with crys-
 tals of a non-deflocculating  salt.   After  dissolving,  part of the salt enters the
 bottom  with the seepage  flow.   The  rate of advance of  the peak of the resulting salt
 concentration 'wave' in  the bottom material is measured with an  electrical conductiv-
 ity probe.   Laboratory  studies showed that the seepage rate could be  calculated by
 multiplying this salt penetration rate  by  the porosity of bottom material.  A field
 study in a  reservoir showed excellent agreement between the seepage obtained  in this
 manner  and  the rate of  fall of the  water surface.  The salt-penetration technique is
 simple  and  it can be carried out under  a wide variety  of  canal conditions.
 68-69:04A-005
 DISTRIBUTION OF  PESTICIDES  IN  SURFACE WATERS,
 King,  P.  H., Yeh,  H.  H., Warren,  P.  S.,  and  Randall, C. W.
 Virginia  Polytechnic  Institute, Blacksburg,  Dept of Sanitary Engineering.
 Journal of  the American Water  Works  Association, Vol.  61, No. 9, p 483-486, September
 1969.  7  fig, 2  tab,  7 ref.

 Descriptors:  *Pesticide kinetics, *Pesticide removal, *Adsorption, Soils, Coals,
 Distribution patterns, Activated  carbon, Clays, Algae, Water purification, Water
 quality,  Water chemistry.
 Identifiers:  Pesticide sorption.

 Several papers on  pesticide distribution in  water, pesticide sorption in soil, and
 pesticide removal  technology are  reviewed and summarized, and experimental data are
 presented on pesticide sorption by soils, algae, and activated carbon.  The pesti-
 cides  studied are  lindane and  parathion.  Experimental results are shown by sorption
 isotherms.  In general, high-clay soils adsorbed about twice as much pesticide as
 sandy  soils.  Algae sorbed about  10  times as much as soils.  Coal adsorbed about 2\
 times  as  much as soil, and activated carbon  adsorbed about 4 orders of magnitude
 more than soil.
68-69:04A-006
MECHANICAL STRUCTURES FOR FARM IRRIGATION,
Humpherys, Alan S.
Agricultural Research Service, Kimberly, Idaho.
American  Society of Civil Engineers Proceedings, Journal of the Irrigation and Drain-
age Division, Vol. 95, No. IR4, p 463-479, December 1969.  17 fig, 2 tab, 3 ref, 3
append.

Descriptors:  *Automation, *Irrigation systems, *Automatic control, *Control struc-
tures, *Hydraulic gates, Irrigation, Irrigation practices, Irrigation engineering,
Turnouts, Mechanization, Water control, Movable dams, Water distribution (Applied),
Timing, Farm equipment, Control systems, Check structures, Check dams, Furrow irriga-
tion.

Mechanical, automatic irrigation structures that can save water and labor are being
developed for surface irrigation systems.  The timer-controlled and automatic water-
pressure-controlled structures are being tested in various types of irrigation sys-
tems.  A specially designed mechanical timer is used to control semiautomatic irriga-
tion checks and gates.  Generalized design information is presented for a timer-

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controlled check dam for lined and unlined ditches.  A pressure gate that opens and
closes automatically when water in the channel approaches a certain depth is describ-
ed.  Other structures include a drop gate, metal apron gate, and water level control
checks.  Certain operational problems such as rodent and weed control require greater
emphasis with automatic irrigation than with conventional systems.
68-69:04A-007
A CLIMATOLOGICAL-TECHNOLOGiCAL METHOD FOR ESTIMATING IRRIGATION WATER REQUIREMENTS
FOR MAXIMUM CROP YIELDS,
Changnon, Stanley A., Jr.
Illinois State Water Survey, Urbana.
Journal of Soil and Water Conservation, Vol. 24, No. 1, p 12-15, January-February
1969.  4 tab, 13 ref.

Descriptors:  *Irrigation efficiency, *Irrigation water, *Crop production, Crop re-
sponse, Regression analysis. Forecasting, Irrigation practices, Supplemental irriga-
tion, Illinois, Consumptive use, Evapotranspiration, Climates, Weather, Rainfall,
Temperature.
Identifiers:  Irrigation water requirements.

A method is given for estimating irrigation water requirements, using regression ana-
lysis of weather and crop production data including preseason precipitation, monthly
mean temperatures, and monthly precipitation.  The data used are from Illinois for
the period 1930-1963.  The results of analysis are tabulated for the 12 regional sub-
divisions of Illinois in terms of % increase of yield, weather types, July-August
conditions, and frequency of yield increase for given amounts of irrigation water.
The frequency information is accurate enough to use in planning irrigation water sup-
plies anywhere historical climate and yield data are available.
68-69:04A-008
SOME ENVIRONMENTAL EFFECTS OF DRAINAGE IN FLORIDA,
Storch, William V., and Taylor, Robert L.
Central and Southern Florida Flood Control District, West Palm Beach.
American Society of Civil Engineers Proceedings, Journal of the Irrigation and Drain-
age Division, Vol. 95, No. IR1, Paper No. 6460, p 139-151, March 1969.  6 fig.

Descriptors:  *Drainage, *Wetlands, *Florida, *Environmental effects, Citrus fruits,
Economics, Estuaries, Flood control, Irrigation, Sedimentation, Water quality, Fish,
Ecology, Plants, Social aspects, Conservation, Public rights.
Identifiers:  Lake Okeechobee-Everglades Basin  (Florida).

In 1959, intensive agricultural development started in a 780 sq mi region lying east
of Lake Okeechobee in south Florida.  In this  'wetland' region of flats, sloughs and
ponds effective drainage to coastal waters has been the key to agricultural expansion
By 1967 approximately 20% of the region was planted in citrus.  Changes in the natur-
al environment within the region took place almost immediately after drainage was
initiated and indicates that the natural environment in adjacent areas can be affec-
ted as well.  The effect of drainage on the immediate economic environment of the reg-
ion has been favorable to date.  However, natural environmental changes have produced
tensions, with economic overtones, in the social environment resulting in conflict
between agricultural and conservationist interests.  Based on the experience gained
in this region it is suggested that the proper function of public government is to
evaluate the possible environmental effects of drainage programs and to use its fi-
nancial, persuasive and regulatory powers to guide total environmental change in ac-
cordance with its estimate of the best public interest.
68-69:04A-009
A STUDY OF THE DRAINAGE OF IRRIGATED SAND DUNES USING AN ELECTRICAL RESISTANCE ANA-
LOGUE,
Mein, R. G., and Turner, A. K.
Water Conservation and Irrigation Commission, N.S.W.  (Australia).
Journal of Hydrology, Vol. 6, No. 1,  p 1-14, January 1968.  9 fig, 13 ref.

Descriptors:  *Resistance, *Analog models, *Dunes, *Electrical resistance, Irrigation
effects, Drainage, Model studies.
                                     Ill

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 Identifiers:   *Artificial drainage,  New South Wales,  Impermeable  layer.

 The drainage  of irrigated sand dunes by means of  an  electrical  resistance  analog  is
 described.  Sand dunes to be irrigated in New South  Wales  can be  described as having
 an impermeable layer represented by  either a horizontal  plane at  the  base  or a plane
 parallel to a sloping face.   The artificial drainage  of  these dunes differs from  sit-
 uations covered by formulae  commonly used for flat land.   The electrical resistance
 analog is shown to be suitable for studying sand  dune problems.   The  analog solutions
 are compared  with the theoretical predictions of  the  appropriate  formulae.  Based on
 results obtained, recommendations are made on the best means of draining these sand
 dunes.
 68-69 :04A-010
 FACTORS  AFFECTING  INFILTRATION  AND  RECHARGE  IN A LOESS COVERED BASIN,
 Williams,  Roy  E.,  and  Allinan, David W.
 Idaho  University,  Moscow.
 Journal  of Hydrology,  Vol.  8, No. 3,  p  265-281, July  1969.   13 fig,  16 ref.

 Descriptors:   *Groundwater  recharge,  *Artificial recharge, *Infiitration, *Loess,
 *Percolation,  Groundwater,  Water  table, Crops, Infiltrometers, Root  systems, Hydro-
 geology, Piezometers,  Aquifers, Idaho,  Dyes,  Tracers, Hydrographs, Soil erosion,
 Bibliographies.
 Identifiers:   Holes, Groundwater  system.

 Hydrographs of shallow piezometers  installed  in a basin overlain primarily by loess
 reveal that water  infiltrating  and  percolating through the loess recharges ground-
 water.   Local  gravity  groundwater flow  systems adjacent to some intermittent streams
 thereby  are established.  Relief  on the water table is at a  maximum  during late win-
 ter or spring, but decreases steadily through the summer when dry weather and maximal
 evapotranspiration minimize recharge.  Cultivation practices and type of crop grown
 are 2  important  factors that make the loess  susceptible to infiltration and percola-
 tion.  Smooth, heavily worked surfaces  (commonly planted in  winter wheat) act as a
 major  limitation to infiltration  capacity; soil moisture concomitantly is low beneath
 such surfaces.  Root mats developed  beneath  grassy surfaces  provide  optimal condi-
 tions  for  infiltration and, consequently,  for recharge.  Measured infiltration capa-
 cities are often influenced by  near-vertical  tubular  openings extending at least 30ft
 deep in  the loess.  Tracer  studies  indicate  that when sufficient water is available
 and when surficial infiltration capacity is  sufficiently high to form a zone of posi-
 tive pressure  above these openings, water  is conducted ahead of the  saturation front.
68-69:04A-011
ANALYTICAL AND COMPUTER SOLUTIONS OF TRANSIENT WATER TABLES FOR DRAINAGE OF SLOPING
LAND,
Chauhan, H. S., Schwab, G. O., and Hamdy, M. Y.
Ohio Agricultural Research and Development Center, Columbus.
Water Resources Research, Vol. 4, No. 3, p 573-579, June 1968.  8 fig, 21 ref.

Descriptors:  *Drainage, Analog computers, *Drawdown, Water management (Applied),
*Drainage systems, Land management, *Porous media, Non-uniform flow, Mathematical
studies, Laplaces equation, Stokes law, *Tile drains.
Identifiers:  Boussinesq equation, Time-variable end conditions, Transient water
tables.

Transient water table drawdown ir. sloping land lying between parallel, open ditches
was obtained by solving Bcussinescr's equation on the analog computer and by analyti-
cal methods for zero and time-variable end conditions at the ditches.  Comparison of
the results with observations mads on a viscous flow model indicated chat the solu-
tion with time-variable end conditions described the flow region better then the sol-
ution with zero end solutions.
                                     11;

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68-69:04A-012
STOP WATERWEEDS WITH CHEMICALS,
Schachterle, D. M.
Bureau of Reclamation, Denver, Colorado.
Reclamation Era, Vol. 54, No. 4, p 108-109, November 1968.  3 fig.

Descriptors:  *Aquatic weed control, Cattails, Pondweeds, * Irrigation canals, Ponds,
Pondweeds, *Herbicides, *Aquatic plants, Irrigation operation and maintenance,
Paints.
Identifiers:  *Copper sulfate, *Xylene, *Dalapon, *Aquathol,  Residue, *Watermilfoils,
Reeds, Green algae.

Waterweeds are on the rampage throughout the West, particularly in irrigation canals
and laterals.  Increased use of herbicides to control weeds was limited due to the
possible toxic effects on humans, warm blooded animals, fish, aquatic animals and
plants, and its persistence level in soil and water.  Aquatic plants were classified
in three main categories:  submersed, emersed and those that float or attach to sur-
faces.  The aquatics reduce flows, cause increased siltation, and plug sprinkler
irrigation and irrigation control devices.  There were 20 herbicides registered for
use with 11 being non-toxic to fish at the concentration used tc control weeds.
Costs of treatment were paid as operation and maintenance costs by the water user.
Average cost for chemical contra! in Colorado was given.
68-69:04A-013
GEOMORPHIC GROUPING OF SOILS IN WATERSHED ENGINEERING,
England, C. B., and Holtan, H. N.
Hydrograph Laboratory, Beltsville, Maryland.
Journal of Hydrology, Vol. 7, No. 2, p 217-225, 1969.  3 figs, 2 tab, 20 ref.
(See 68-69:040-001)
                                     113

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                                    SECTION XV


                       WATER QUANTITY MANAGEMENT AND CONTROL

                         WATERSHED PROTECTION (Group 04D)


68-69:040-001
GEOMORPHIC GROUPING OF SOILS IN WATERSHED ENGINEERING,
England, C. B., and Holtan, H. N.
Hydrograph Laboratory, Beltsville, Maryland.
Journal of Hydrology, Vol. 7, No. 2, p 217-225,  1969.  3 figs, 2 tab, 20 ref.

Descriptors:  *Hydrology, *Watersheds, *Geomorphology, Soil classification, Infiltra-
tion, Rainfall, Runoff.

Soil properties significant to processes of infiltration,  moisture storage, drainage,
and the hydraulics of surface flow are related to topographic position.  Areal and
elevational distributions of soils provide a basis for interpretative grouping of
soil mapping units in computations for watershed engineering.  Soils on an ARS experi-
mental watershed, grouped by deep upland, shallow hillside, and very deep deposition-
al,  were plotted on a contour map of the watershed surface.  The elevational sequ-
ences thus obtained are representative of the hydraulic relationships between hydro-
logic response units in small agricultural watersheds.  Profile characteristics,
areal distribution, and relative elevation position of the units determine watershed
response to storm rainfall.
                                     115

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                                     SECTION XVI


                       WATER QUALITY MANAGEMENT AND PROTECTION

                      IDENTIFICATION OF POLLUTANTS  (Group 05A)


68-69:05A-001
EXTRACTION OF CATIONS FROM SILICATE MINERALS DURING THE DETERMINATION OF EXCHANGEABLE
CATIONS IN SOILS,
Rhoades, J. D., and Krueger, D. B.
Agricultural Research Service, Riverside, California.
Soil Science Society of America Proceedings, Vol. 32, No. 4, p 488-492, July-August
1968.  1 fig, 7 tab, 21 ref.

Descriptors:  *Soil analysis, Potassium, *Sodium, *Magnesium, Calcium, Alkaline earth
metals, Arid lands.
Identifiers:  *Soil minerals, Ammonium acetate extraction.

The extent to which silicate minerals release Ca, Mg, Na, and K during the determina-
tion of exchangeable cations in soils by the ammonium-acetate-extraction procedure
was evaluated.  The method of exchangeable-sodium evaluation used by the U.S. Salin-
ity Laboratory was employed for this study with the exception that soil samples were
replaced with reference mineral samples.  Amounts of cations equivalent to 0.3,to
21.8 meg/100 g were extracted from the minerals by ammonium acetate.  In general,
the proportions of cations extracted decreased in the order Ca + Mg »Na>K.  Because
of this phenomenon, complications are expected to occur in the evaluation of exchange-
able Ca and Mg in arid-land soils, but not for exchangeable Na except under unusual
circumstances.  The latter circumstances are described and the general extent of
error that may occur is estimated.
68-69:05A-002
A BATTERY POWERED PROPORTIONAL STREAM WATER SAMPLER,
Fredriksen, R. L.
Forest Service  (USDA), Corvallis, Oregon, Pacific Northwest Forest and Range Experi-
ment Station.
Water Resources Research, Vol. 5, No. 6, p 1410-1413, December 1969.  4 fig.

Descriptors:  *Sampling, * Instrumentation, *Water quality, Water analysis, Data
collections, Automation, Equipment.
Identifiers:  Water samplers.

A stream water sampler was designed and tested to sample water from a stream at a
rate proportional to the streamflow rate.  A composite of samples taken in this
manner is an estimate of the mean concentration of constituents carried by the stream
while the sample was collected.  The instrument is suitable for estimates of trans-
port of suspended or dissolved constituents  in small streams.  The sampler can be
built for under $1000.
68-69:05A-003
POLLUTION SURVEILLANCE BY NONCONTACT INFRARED TECHNIQUES,
Van Lopik, J. R., Rambie, G. S., and Pressman, A. E.
Texas Instruments, Inc., Dallas.
Journal of Water Pollution Control Federation, Vol. 40, No. 3, Part 1, p 425-438,
March 1968.  14 fig, 10 ref.

Descriptors:  *Remote sensing, *Path of pollutants, *Water pollution, *Monitoring,
Surveys, Pollutant identification, Assessments, Instrumentation, Methodology, Texas.

Airborne infrared mapping techniques and their application to identification and mon-
itoring of pollutants in streams and other bodies of water are described and illus-
trated.  Thermal, organic and inorganic pollution can be determined and monitored,
thus providing for rapid means to make on-the-ground measurements and, with aerial
surveys, synoptic assessments of pollution parameters.  Infrared mapping methods
show the differences in infrared radiation flux over the area mapped.  Sensing of
temperature by this means can be used to map isotherms in water bodies and to trace
                                     117

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 thermal pollution, such as has been done in Galveston Bay.   Proper selection  of
 wavelengths allows identification of contaminants by their  spectral emissivity char-
 acteristics .
 68-69:05A-004
 ECONOMIC ISSUES IN CONTROLLING AGRICULTURAL POLLUTION,
 Taylor, G. C.
 Economic Research Service, Washington, D.C.
 Paper presented at the American Agricultural Economics  Association Meetings,  Lexing-
 ton, Kentucky, August 19-20, 1969.  14 ref.

 Descriptors:   *Pollutants, *Agriculture,  Decision making,  Water pollution,  Wastes,
 Sediments, Pesticides.

 The objectives of this paper are to:  (1)  stress the multiple decision making  aspects
 of controlling environmental pollution; (2) to highlight a number  of  significant
 economic issues involved;  and (3)  to suggest some significant areas where economic
 research can  contribute to reduction of agriculturally  related pollution.   The  agri-
 cultural pollutants considered were pesticides, animal  wastes, sediment,  plant nutri-
 ents, inorganic salts and  minerals, forest and crop residues,  agricultural  processing
 wastes, and smoke, dusts,  and other air pollutants.  Sediment is the  largest  single
 pollutant of  surface water.   Decisions on environmental management are made at  diff-
 erent points  in time by millions of individuals and organizations,  and it was propos-
 ed that to highlight a number of economic issues within a  three-tier  hierarchy  of
 decision making levels, these levels were: first, the individual or firm; second, the
 bureaucratic  and legal systems that operate to facilitate  and constrain decisions at
 the first level;  and topmost, the  arenas  of the legislature, the commissions, the
 high courts,  and even the  industry board  rooms where broad decisions  affecting  the
 second  level  framework are made.
 68-69:05A-005
 DETERMINATION  OF  ORGANOCHLORINE  INSECTICIDES  IN  SOILS AND  WATERS,
 Pionke,  H.  B.,  and  Chesters,  G.
 Wisconsin University,  Madison, Dept  of  Soils.
 Soil  Science Society  of  America  Proceedings,  Vol.  32, No.  6,  p  749-759,  November-
 December 1968.  82  ref.

 Descriptors:   *Analytical  techniques, *0rganochloride insecticides,  *Application meth-
 ods, Column chromatography, Thin-layer  chromatography,  Gas liquid  chromatographic
 techniques.
 Identifiers:   *Soil,  *Water,  Methods of equilibrating.

 Pertinent references  on  the determination of  organochloride  insecticides in  soil and
 water  samples  are reviewed.   The  particular methods are chosen  because of  their app-
 licability  to  heterogeneous systems  which often  provide problems due  to  coextraction
 of  indigenous  components.  The review is divided into three  principal sections, i.e.,
 extraction  of  organochlorine  insecticides from soils and waters, cleanup of  soil and
 water  extracts, and analysis  of purified soils and water extracts.  Criteria used in
 evaluating  extraction procedures  were based on methods  of  equilibrating  the  insecti-
 cide with the  soil  sample  and the control of  possible insecticide  losses through deg-
 radation and volatilization.  A large portion of the methods  of final analysis of
 purified extracts is  given over to gas-liquid chromatographic techniques.  The gas-
 liquid chromatographic methods are discussed  on  the basis  of  peak  resolution, detec-
 tion and measurement  of  the insecticides, and confirmation of their identity.  Thin-
 layer  chromatographic, spectrophotometric, and other methods  of determination of or-
 ganochlorine insecticides  in  purified extracts are evaluated.
68-6."1: 05A-006
MOVEMENT OF HERBICIDES IN RUNOFF WATER,
Sheets, T. J., and Lutz, J. F.
North Carolina State University, Raleigh, Pesticide Residue Research Laboratory.
Paper presented at the 1969 Winter Meeting, American Society of Agricultural Engin-
eers, December 9-12, 1969, Chicago, Illinois.  8 p, 2 fig, 3 tab, 3 ref.

Descriptors:  *Herbicides, 2,4-D, 2,4,5-T, *Pollutants, Path of pollutants, *Water
pollution, Ground water,  *Runoff, Weed control, Defoliants, Persistence, Environmental
effects.

                                     118

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Identifiers:  *Dicamba, *Picloram, Halewood clay loam.

Salts and esters of 4-amino-3,5,6-trichloropicolinic acid (picloram),  2,4,5-trichlor-
ophenoxyacetic acid (2,4,5-T),  and a few other phenoxy acids are widely used for con-
trol of perennial herbaceous weeds and woody plants throughout the United States.
Also, these herbicides have been employed as defoliants in Southeast Asia.   This pro-
ject was initiated to study  (a) movement of picloram, 2,4-dichlorophenoxyacetic (2,4-
D), 2,4,5-T, and 3,6-dichloro-o-anisic acid (dicamba) in surface and ground water and
(b) distribution and persistence of the herbicides in soil.   This discussion was res-
tricted to movement in water.
68-69-.05A-007
CHROMATOGRAPHIC MODEL FOR PREDICTING PESTICIDE MIGRATION IN SOILS,
King, P. H., and McCarty, P. L.
Virginia Polytechnic Institute and Stanford University
Soil Science, Vol. 106, No. 4, p 248-261, 1968.  5 fig, 5 tab, 11 ref.

Descriptors:  *Pesticides, Leaching, Soil water, Insecticides, Agronomy, Soil manage-
ment.
Identifiers:  Phosphorus insecticides, Pesticide movement.

The analysis of experimental data and its correlation with theoretical curves estab-
lishes the feasibility of predicting the extent to which organic phosphorus insecti-
cides may be leached through soil columns.  The method used for this prediction
employs an equation describing chromations which would be expected in typical agri-
cultural practice.  The degradation of the pesticide molecule may normally be esti-
mated from an equation describing first order decay kinetics.  The combination of
these two considerations is generally sufficient to develop a predicted elution curve
for any pesticide through any soil assuming some available basis for estimating the
distribution of the pesticide in soil-water environment and the decay reaction rate
constant under the environmental conditions encountered.  The major limitations of
this method from the variability in distribution which occurs when the water solu-
bility of the pesticide is approached, from the increased degradation of pesticide
which occurs when biological acclimation takes place, and from the variability in
theoretical plate height observed with differing soils and packing arrangements.
68-69:05A-008
AN ACID-FREE BATHOPIIENANTHROLINE METHOD FOR MEASURING DISSOLVED FERROUS IRON IN LAKE
WATERS,
McMahon, J. W.
Chalk River Nuclear Laboratories, Ontario, Canada.
Water Research, Vol. 3, No. 10 p 743-748, 1969, 2 tab, 10 ref.

Descriptors:  *Iron, Bodies of Water, Filtration, Lake, *Acids.
Identifiers:  *Acid-free bathophenanthroline method.

An acid-free solvent extraction technique, using bathophenanthroline, is proposed for
measuring dissolved ferrous iron in filtered lake water.  Ommission of HC1 from the
reagents eliminates the influence of acid and light on ferrous iron determinations.
The effects of membrane filtration and ferric-bathophenanthroline interference on
absorbance at 533 mu are discussed.
68-69:05A-009
DISTRIBUTION OF CHLORINATED INSECTICIDES IN CULTIVATED SOIL,
Nash, R. G., and Woolson, E. A.
Agricultural Research Service, Beltsville, Maryland.
Soil Science Society of America Proceedings, Vol. 32, No. 4, p 525-527, July-August,
1968, 1 fig, 2 tab, 16 ref.

Descriptors:  *Soil, * Insecticides, Aldrin, Dieldrin, Heptachlor, Pesticide residues,
Cultivated lands.
Indentifiers:  Chlorinated insecticides.

The 1966 distribution of nine chlorinated insecticides in a 38 cm profile was deter-
mined in a Congaree sandy loam soil which had received accumulations of 73 or 146
kg/ha as frequently repeated foliar applications during the 1951, 1952, and 1953

                                      119

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growing seasons.  Residues of aldrin  (pure and technical-determined as dieldrin
because only trace amounts of aldrin were detected), dieldrin, isodrin + endrin,
endrin, heptachlor + heptachlor epoxide, chlordane, BHC, toxaphene, and Dilan were
found throughout the profile.  BHC and isodrin were more uniformly distributed
throughout the profile than aldrin, dieldrin, Dilan, Toxaphene, and chlordane.  Be-
tween 85 and 90% of the latter insecticides were concentrated in the upper 23 cm,
which probably corresponds to the cultivated layer.  Residues were greatest in the
7.6 to 23 cm depths and least below the 23 cm depth.  The relative mobility of the
insecticides was BHC >_ isodrin > heptachlor > endrin > toxaphene >^ dieldrin >^ aldrin
> Dilan > chlordane.
                                    12Q

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                                     SECTION XVII


                       WATER QUALITY MANAGEMENT AND PROTECTION

                          SOURCES OF POLLUTION (Group 05B)


68-69:058-001
EXTRACTION OF CATIONS FROM SILICATE MINERALS DURING THE DETERMINATION OF EXCHANGEABLE
CATIONS IN SOILS,
Rhoades, J. D., and Krueger, D. B.
Agricultural Research Service, Riverside, California.
Soil Science Society of America Proceedings, Vol. 32, No. 4, p 488-492, July-August
1968.  1 fig, 7 tab, 21 ref.
(See 68-69:05A-001)
68-69:058-002
PREDICTING RETURN FLOWS FROM IRRIGATION,
Hurley, Patrick A.
Bureau of Reclamation, Denver, Colorado, Office of Atmospheric Water Resources.
American Society of Civil Engineers, Proceedings, Journal of the Irrigation and Drain-
age Division, Vol. 94, No. IR1, Paper No. 5838, p 41-48, March 1968.  3 fig, 3 tab,
3 ref.

Descriptors:  *Return flow, *Irrigation, *Surface-groundwater relationships, Drainage
effects, Drains, Deep percolation, Evapotranspiration.
Identifiers:  Transient storage, Graphical solutions.

An analytical method for computing return flow or drainage from irrigation applica-
tions is presented and discussed.  Computations consider aquifer properties, drain
spacing, and deep percolation.  A graph for determining the fractional part of per-
colation remaining in transient storage is included.  By using the graph and simple
digital procedures, realistic estimates of irrigation return flow can be determined.
The method was used to determine monthly quantities for 13 yr of return flows in the
Mesilla Valley, New Mexico-Texas.
68-69:058-003
PLANT NUTRIENTS IN BASE FLOW OF STREAMS IN SOUTHWESTERN WISCONSIN,
Minshall, Neal, Nichols, M. Starr, and Witzel, S. A.
Wisconsin University, Madison.
Water Resources Research, Vol. 5, No. 3, p 706-713, June 1969.  1 fig, 1 tab, 9 ref.

Descriptors:  *Water chemistry, *Solutes, *Nutrients, *Base flow, *Wisconsin, Nitro-
gen compounds, Phosphorus compounds. Potassium compounds,             Leaching, Wea-
thering, Runoff.
Identifiers:  Wisconsin River.

A 2-yr study was made of plant nutrients in the base flow of SW Wisconsin streams.
The average base flow from 36 drainage areas covering a total of 643 sq mi was 4.9
in/yr.  The annual nutrient losses in base flow were nitrogen, 1.1 Ibs/acre; phosphor-
us, 0.10 Ib/acre; and potassium, 1.8 Ibs/acre.  These losses were only 1/4 of those
in the 1967 surface runoff from 0.01-acre plots at the Lancaster Experimental Farm and
3 Agricultural Research Service watersheds near Fennimore, Wisconsin.  If precipita-
tion of about 32 in. in a normal year contains 10 Ibs N/acre, fertilizer applications
20 Ibs N/acre, and subsurface or base flow an average of only 1 Ib N/acre, then the
other 29 Ibs must be lost in surface runoff, retained for plant growth, or lost
through denitrification.  Total P lost per year, in the base flow, was 0.1 Ib/acre,
which is approximately 2% of the amount applied and only 1/10 of that lost in the
1967 spring surface runoff from the Lancaster plots and Fennimore watersheds.  Solu-
ble K lost per year in the base flow was about 2 Ibs/acre, about 10% of that applied
and only 1/4 of that lost in the 1967 spring surface runoff.
                                     121

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 68-69:05B-004
 AGRICULTURAL CHEMICALS AND OUR WATER RESOURCES,
 Monke,  E. J., and Goodrich,  P. R.
 Purdue  University, Lafayette, Indiana,  Department of  Agricultural  Engineering.
 Paper Presented at 1968 Annual Meeting  of American Society for  Engineering Education,
 California University, Los Angeles,  June 17-20,  1968.   17  p,  36 ref.

 Descriptors:  *Water pollution sources,  *Water pollution effects,  *Regulation, *Agri-
 cultural chemicals, *Reviews, Bibliographies,  Pesticides,  Fertilizers,  Organic mat-
 ter,  Nutrients,  Eutrophication,  Nitrogen compounds, Legislation, Farm management,
 Land  management.
 Identifiers:  Agricultural effects.

 Literature pertaining to the effects of  agricultural  chemicals  on  water resources was
 reviewed.  An attempt is made to put the contribution  of chemicals from agricultural
 sources in proper perspective and  to predict the  effect of increasing regulation on
 the use and methods of application of agricultural chemicals.   Proper management of
 agricultural chemicals from profit and  safety  motives  alone would  reduce the levels
 of unwanted chemicals reaching water supplies.  Much  greater  research effort is need-
 ed in all phases  of pollution reduction.   In general,  engineering  education should be
 more  concerned with the environment, its  measurement  and control.
 68-69:056-005
 RURAL  RUNOFF AS A FACTOR  IN  STREAM  POLLUTION,
 Weidner,  R. B., Christiansen, A.  G.,  and  Weibel,  S.  R.
 Robert A.  Taft Sanitary Engineering Center, Cincinnati, Ohio, Cincinnati Water Res-
 earch  Lab.
 Journal of Water  Pollution Control  Federation, Vol.  41, No.  3, Part 1, p 377-384,
 March  1969.  6 fig,  10 tab,  3 ref.

 Descriptors:  *Water pollution  sources, *Runoff,  *Farms, *Farm wastes, Bacteria,
 Biochemical oxygen demand, *Erosion,  Phosphates,  Nitrogen compounds, Sediments.
 Identifiers:  Rural runoff.

 Six cropped and mixed agricultural  watersheds under  experimental prevailing and im-
 proved crop land  management  at  Coshocton, Ohio and an apple  orchard over meadow at
 Ripley, Ohio, were instrumented to  sample and gage rainfall  and storm runoff from
 nhe fields.  Under prevailing practices, monthly  volume of runoff from fields was
 higher than that  under improved practices such as contour plowing and strip cropping.
 More runoff developed from a field  in corn than from one in  wheat, and the least
 runoff developed  from fields in meadow.  Good correlations between rural runoff silt
 losses and total  solids, and between  total solids and BOD, COD, total hydrolyzable
 phosphate, and total nitrogen were  found.  Microbial tests showed that the bacterial
 sources were predominantly nonhuman, but total coliforms exceeded 1,000/100 ml in
 90% of the samples in runoff from 2 of the rural watersheds.
68-69:05B-006
CONSERVING RESOURCES AND MAINTAINING A QUALITY ENVIRONMENT,
Wadleigh, Cecil H., and Britt, Clarence S.
Agricultural Research Service, Beitsville, Maryland.
Journal of Soil and Water Conservation, Vol. 24, No. 4, p 172-175, October 1969.
4 ref.

Descriptors:  *Water resource development, *Water pollution, *Eutrophication, Govern-
ment supports, Soil conservation, Industrial wastes, Municipal wastes, Fertilizers,
Pesticides, Soil erosion, Animal wastes, Economics, Nitrogen, Water conservation.
Identifiers:  *Soil runoff, Livestock.

Some of the problems involved in natural resource conservation are presented, with
particular emphasis on the water pollution caused by agricultural runoff and live-
stock production.  It is pointed out that the economics of the farming and livestock
industry are often in conflict with the conservationists interests.  It is suggested
that the Dept of Agriculture adopt ^ cost-sharing pcogram to encourage solutions to
some of the problems.  The article emphasizes the dangers of eutrophication induced
by animal wastes.  The author concludes with a statement of some of the accomplish-
ments of the conservation movement in the area of soil and water resources.

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68-69:058-007
SOIL SALINITY IN THE WEST CENTRAL GEZIRA, REPUBLIC OF THE SUDAN,
Williams, M. A. J.
Australian National University, Canberra, Research School of Pacific Studies.
Soil Science, Vol. 105, No. 6, p 451-464, June 1968.  9 fig, 20 ref.

Descriptors:  *Saline soils, *Soil surveys, Mapping, *Soil texture, Salinity,  Rain-
fall, Permeability, Topography, Drainage, Chemical properties.
Identifiers:  Africa.

Topsoil and subsoil salinity has been mapped for 1.3 m acres of land bordering the
White Nile between Khartoum and Rabak.  Salt reaches a peak in the second horizon
except in the southern coluvial clays, where it increases with depth.  The relations
between salinity and rainfall, soil texture, topography, drainage, and certain soil
chemical properties are discussed.  In closed depressions and on the northern clay
plains, topsoils are saline; on dunes, on certain recent alluvial terraces and on
colluvial upland clays they are non-saline.  Subsoil salinity is highest around
former lake margins, and decreases with increasing elevation.  Dominant salinity con-
trols are soil texture, permeability, and topography, all of which are related to
depositional history.  In this area, rainfall and evaporation have a minor influence
on salt distribution.
68-69:053-008
WATER POLLUTION POTENTIAL ESTIMATED FROM FARM NUTRIENT BUDGETS,
Frink, C. R.
Connecticut Agricultural Experiment Station, New Haven.
Agronomy Journal, Vol. 61, No. 4, p 550-553, July-August 1969.  3 fig, 3 tab, 15 ref.

Descriptors:  *Water pollution, *Nutrients, *Nitrogen, *Phosphorus, Potassium, Ground
water, Eutrophication, Dairy industry, Fertilizers, Agronomy.

Estimates of the yield of nutrients to waterways from wooded and cultivated land vary
considerably.  Some of this variability can be attributed to the large variability
in the N and P content of runoff water, to analytic uncertainties, and to the diffi-
culties of obtaining accurate flow measurements.  As an alternative assessment of
agricultural eutrophication, nutrient budgets were derived for the highly specialized
dairy farms  in the Northeast.  This analysis showed that under certain conditions
these dairy farms could contribute significant amounts of nutrients, particularly
nitrate, to groundwater.  However, this loss of nutrients can be minimized by provid-
ing adequate cropland per cow, by selecting crops and animals that are efficient us-
ers of N, and by applying both manure and commercial fertilizers during the growing
season.
68-69:056-009
INFLUENCE OF SOIL MOISTURE TENSION ON NITRATE ACCUMULATION IN SOILS,
Sabey, B. R.
Illinois University, Urbana, Dept of Agronomy.
Soil Science Society of America Proceedings, Vol. 33, No. 1, p 263-266, January-
February 1969.  6 fig, 1 tab, 12 ref.

Descriptors:  *Soil moisture, *Moisture tension, Nitrates, Nitrification, Saturated
soils.
Identifiers:  *Soil moisture suction, *Ammonium oxidation.

The influence of soil moisture tension on N03~-N accumulation was studied in limed,
silt loam, loessial derived soils to which a non-limiting source of NH^^-N was added.
This was done by saturating the soils in an NH^ solution, then subjecting the sam-
ples to 0, 0.1, 0.33, 1, 5, and 15 bars of soil moisture tension in conventional pos-
itive pressure equipment, and incubating the samples in a saturated atmosphere for
varying intervals, to characterize the NO3~-N accumulation curve with time.  The max-
imum slope of the line gave an estimate of the K^ value or maximum rate of NO-^-N
accumulation in ppm/day.  The K^ values in all soils were greatest at 0.1 bar tension
with KM values decreasing as soil moisture tension increased or decreased.  The rela-
tive rates of NO3~-N accumulation, RM values or moisture rate indexes, varied much
less than KM values among soils.  The mean RM values at 0.1, 0.33, 1, 5, and 15 bars
tension were 1.0, 0.71, 0.53, 0.29, and 0.13, respectively.  The moisture rate index
curve can be used to estimate the amount of N03~-N accumulation in soils similar to


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 those used in this study at all soil moisture tensions  between  0.1  and  15 bars  if
 the rate of NO3~-N accumulation is known at any one tension within  the  above  range.
 The moisture rate index curve of this study and the temperature rate  index curve of
 a previous paper are used in the previously proposed equation,  N-KFRK(t-tprt) to
 estimate NOj~-N accumulation in soils under varying conditions  of temperature and
 soil moisture tension.
 68-69:058-010
 APPLIED NITROGEN LOSSES IN RELATION TO OXYGEN STATUS OF SOILS,
 Meek, B. D.,  Grass, L. B., and MacKenzie,  A.  J.
 Southwestern Irrigation Field Station, Brawley,  California.
 Soil Science Society of America Proceedings,  Vol.  23,  No.  4,  p  575-578,  July-August
 1969.  2 fig, 4 tab, 5 ref.

 Descriptors:   *Nitrates, Nitrogen cycle,  *Denitrification,  Irrigation, Anaerobic
 conditions,  Ground water, Oxygen, Soil water.
 Identifiers:   *Soil redox potential.

 The decrease in soil nitrate nitrogen as  related to  redox  potential  was  studied in
 the laboratory and in the field in Imperial Valley,  California.   Partial anaerobic
 conditions were induced in laboratory flasks  containing an  atmosphere of 21% oxygen
 by adjusting the soil-water ratio.  When  the  water content  of a  soil having a water
 saturation percentage of 48% was increased to 44.5%  or above, large  losses of N2 gas
 occurred both with and without addition of organic matter.  Significant  denitrifica-
 tion coincided with a decrease in the redox potential  (En).   Measurement of redox
 potential and nitrate concentrations of ground water sampled  at  various  depths in an
 irrigated field indicated that nitrate concentration was high near the surface but
 decreased at depths approaching the water  table.   The  diminishing nitrate concentra-
 tion and redox potential, with depth, indicate that  some nitrates were reduced to
 nitrogen gas  before they reached the water table.  Only 1.5%  of  the  280  kg N/hectare
 applied to a  cotton crop (Gossypium hirsutum  L.) was discharged  in the tile effluent
 during  the growing season.  Denitrification in the soil profile  apparently reduced
 the amount of nitrate reaching the tile drainage system.
 68-69:05B-011
 AN  INVESTIGATION  OF  THE  POTENTIAL PROBLEM  OF  INCREASING  BORON CONCENTRATIONS IN
 RIVERS AND  WATERCOURSES,
 Waggott, A.
 Water Pollution Research Laboratory,  Elder Way,  Stevenage  (England).
 Water Research, Vol.  3,  No.  10,  p 749-765, October  1969.   4  fig, 11 tab, 40 ref.

 Descriptors:   *Water  pollution  sources,  *Water pollution,  *Boron, *Pollutant identi-
 fication, Toxicity,  Water pollution treatment, *Sewage treatment.
 Identifiers:   United  Kingdom.

 Sources of  pollution  by  boron are considered  a brief account of the chemical proper-
 ties of borax  and boric  acid is  given.   The literature dealing with boron toxicity
 in  relation to water  pollution  is summarized.  Methods for determining boron in nat-
 ural waters are discussed and experiments  designed  to test the application of one of
 them to sewage and sewage effluents are  described.  Results of determination of boron
 in  surface  waters, sewages,  sewage effluents, and industrial effluents, are given and
 discussed.  The insignificant removal of boron from sewage during normal treatment is
 demonstrated and other methods  for reducing the  boron content of waters are consid-
 ered.  It is concluded that  the  boron concentrations at present found in surface
waters in the  U.K. do not present an  immediate toxicity problem.
68-69:053-012
AGRICULTURE'S EFFECT ON NITRATE POLLUTION OF GROUNDWATER,
Stewart, B. A., Viets, F. G., and Hutchinson, G. L.
Agricultural Research Service, Fort Collins, Colorado.
Journal of Soil and Water Conservation, Vol. 23, No. 1, p 13-15, January-February
1968.  1 fig, 1 tab, 8 ref.
(See 68-69:02F-051)
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68-69:056-013
PHOSPHORUS FERTILIZATION OF HOPS,
Boawn, L. C., and Rasmussen, P. E.
Agricultural Research Service, Prosser, Washington.
Agronomy Journal, Vol. 61, No. 2, p 211-213,  March-April 1969.   4 tab,  3  ref.

Descriptors:  *Fertilization, *Phosphorus,  Plant physiology,  *Crop response.
Identifiers:  *Hops, Humulus lupulus, P-induced zinc deficiency. Alpha  acid,  *Ex-
tractable soil P.

Hops were grown on field plots treated with five levels of phosphorus fertilization
to determine the effect of P on vine growth,  cone quality, and zinc nutrition.   A
maximum P treatment of 1,344 kg/ha, applied over a 5-year period, increased the ex-
tractable P level of the surface 20 cm of soil from 10 ppm to approximately 100 ppm.
The P level in leaves and cones from this treatment was increased by approximately
0.10 to 0.15% P as compared with the no-P treatment.  Increased levels  of P had no
observable effect on vine color and vigor or on total growth as determined by vine
green weight.  The critical level for P in sidearm leaves at early bloom was indicat-
ed to be below 0.25%.  The alpha acid content of cones decreased where  P fertiliza-
tion exceeded approximately 500 kg/ha.  However, this decrease was poorly correlated
with the P content of leaves, indicating the lack of a direct causal relationship.
The P treatments caused a definite reduction in the Zn concentration in leaf and cone
tissues, but did not induce observable Zn deficiency symptoms.
68-69.-05B-014
THE FATE OF NITRATES UNDER IRRIGATED AGRICULTURE,
Edwards, D. M., Fischbach, P. E., and Young,  L.  L.
Nebraska University, Lincoln, Dept of Agricultural  Engineering.
American Society of Agricultural Engineers, 1969 Winter Meeting,  December 9-12,  1969,
Chicago, Illinois, Sherman House, Paper No. 69-751.  13 p, 6 fig, '14 ref.

Descriptors:  *Nitrates, *Water pollution, *Irrigation, Irrigation practices,  Water
reuse. Saturate flow. Runoff, Fertilizers, *Water pollution sources. Furrow irriga-
tion.

The movement of nitrates under irrigated field and  laboratory conditions has been
investigated.  Nitrogen was applied to the soil by  either mechanical chiseling or
through the influent waters.  First, a laboratory simulation of water movement in a
furrow was made to determine if nitrates move from  a band of fertilizer placed below
the soil surface and to determine the magnitude of  nitrate movement from the fertil-
izer through the soil profile when water is applied to the soil surface.  The second
phase of the study was a correlation between the laboratory study and actual field
conditions.  The third phase was a. laboratory investigation to determine the downward
rate of movement of nitrates into the soil profile.  Once nitrates move below the
soil surface they do not re-enter the runoff water  except possibly through soil ero-
sion and plant residuals left on the soil surface.   Nitrates move essentially with
the wetting front when the soil is initially air dry.  Nitrates do not move at the
same rate as the water when the soil is initially saturated.  A runoff water re-use
system is needed to prevent pollution of surface water due to runoff from an irriga-
ted field when nitrogen fertilizer is injected into the influent water.  With a prop-
erly designed and managed irrigation system, little or no movement of nitrates out-
side the root zone should occur.
68-69:058-015
POLLUTANTS IN DRAINAGE RUNOFF,
Schwab, G. O., Taylor, G. S., and Waldron, A. C.
Ohio State University, Columbus,  Dept of Agricultural Engineering.
American Society of Agricultural Engineers, 1969 Winter Meeting, December 9-12, 1969,
Chicago, Illinois, Sherman House, Paper No. 69-710.  8 p, 4 tab, 15 ref.

Descriptors:  *Drainage water. Surface runoff, Drainage, Path of pollutants, *Pollu-
tants, *Water pollution, Pollution abatement. Fertilizers, *Pesticides, Phosphorus,
Nitrogen, 24-D, Heptachlor, *Sediment.
Identifiers:  Atrazine, Dicamba.

Drainage water from tile and surface drains in a heavy-textured soil in northern Ohio
was analyzed for sediment, plant nutrients, and several pesticides over a 3-year per-
iod.  In 1967 and 1968 drainage water samples were collected from two 3-inch


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 irrigations each year, but not from rainfall.  In 1969 samples were obtained  for  the
 7-month growing season, during which one 3-inch irrigation was applied arid  a  11.6-
 inch flood occurred.  The tiled plots were level and surrounded with a dike to pre-
 vent surface runoff.  Corn was grown each year.  Half of the plots  received conven-
 tional tillage and the other half were not tilled.   In all plots, weeds were  con-
 trolled by chemicals.  The average sediment and nutrient losses from each of  the  five
 3-inch irrigations were generally low.  From the first irrigations  following  pesti-
 cide application, atrazine losses averaged 10.7% of the amount applied for  the tile.
 Losses of 2, 4D in 1967 were only about 0.1% of the amount applied.   Dicamba  losses
 for the 1969 growing season varied from 27 to 37% of the amount applied.  Loss of
 heptachlor for the 1969 season was insignificant.  For the 1969 growing season, sedi-
 ment in the drainage water from the conventional tillage plots contained five times
 or more sediment than from the no-tillage plots.
 68-69:058-016
 MOVEMENT OF HERBICIDES IN RUNOFF WATER,
 Sheets,  T.  J.,  and Lutz,  J.  F.
 North Carolina State University, Raleigh,  Pesticide Residue  Research  Laboratory.
 Paper presented at the 1969  Winter Meeting,  American Society of  Agricultural Engin-
 eers, December 9-12, 1969, Chicago, Illinois.   8 p,  2 fig, 3 tab,  3 ref.
 (See 68-69:05A-006)
 68-69:05B-017
 EFFECTS OF SOIL AND CROP MANAGEMENT PRACTICES ON THE  REMOVAL  OF  STRONTIUM-90 BY PLANT
 UPTAKE, LEACHING,  RUNOFF AND EROSION,
 Haghiri,  F.
 Ohio  Agricultural  Research and  Development  Center, Wooster, Ohio.
 Agronomy Journal,  Vol.  61, No.  5,  p 793-796,  September-October,  1969.   2  fig, 7 tab,
 11  ref.

 Descriptors:   *Planting management, *Erosion,  *Leaching,  *Runoff, Strontium, Radio-
 isotopes,  *Rotations,  Plant growth substances.
 Identifiers:   Leachate.

 Long-term field investigations  are being  conducted to  study the  effect  of management
 practices on the removal of 90gr ky runoff, leaching,  erosion and plant uptake.  The
 management practices consist of one crop  rotation with high and  low rates of lime,
 permanent grass, continuous corn,  and  gravel  mulch with no vegetation.  Over a 5-year
 period,  the 90gr content of .the soil in a 0-10-cm depth decreased in all cropping
 systems.   The  percent  "^Sr loss by runoff water  and sediment  was negatively correla-
 ted with  time  while the  percent 90sr j_n the leachate water increased with time.  The
 percent 9°Sr removal by  runoff  and leachate water has  maximum under gravel mulch and
 minimum under  grass treatments.  Sod crops were  more effective in minimizing the 90gr
 loss  in runoff and leachate water  than cultivated crops.  High Ca accumulating crops
 such  as alfalfa removed  more 9^Sr  than low accumulators such  as  corn.   High rates of
 lime  reduced the 9°Sr uptake by crops  and the  removal  by  leachate water.
68-69:05B-018
NUTRIENTS  IN AGRICULTURAL TILE DRAINAGE,
Pierce, W. H., Beck, L. A., and Glandon, L. R., Jr.
Federal Water Pollution Control Administration, Alameda, California.
1969 Winter Meeting American Society of Agricultural Engineers, December 9-12, 1969,
Chicago, Illinois, Sherman House, Paper No. 69-709.  29 p, 9 fig, 6 tab, 17 ref.

Descriptors:  *Nitrates, Drains, *Drainage water, *Tile drainage. Water quality,
*Water pollution sources, Path of pollutants, Soil water, *Fertilizers, Phosphorus,
Denitrification. Soil moisture, Nitrogen, Soils.
Identifiers:  *San Joaguin Valley.

A number of tile drainage systems were selected for monitoring within each heavily
tiled area.  Larger systems with a large number of rather closely spaced laterals
on as many different soils as available were selected.  Only tile drainage systems
underlying fields having active irrigation and fertilization program were selected.
Wide variations were observed in tile drainage discharge and nutrient concentrations
between the various systems monitored for any given time of year.  Field investiga-
tions were initiated to develop estimates of the amount of nitrogen contributed by



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fertilizers and residual soil nitrogen to tile drainage nitrogen yields.   Four tile
fields were selected, and at each field soils, soil moisture at tile depth,  soil
moisture at depths of 10, 15, 20 and 25 ft, and tile drainage were sampled and ana-
lyzed for nitrates, chlorides and conductivity.  Field studies of soils were conduc-
ted to characterize soil stratigraphy, and determine field moisture, nitrate-nitrogen
and specific conductivity in order to locate the lateral and up-slope limits of the
high-nitrate bearing soils.  Denitrification losses from several soils, under satur-
ated conditions, were studied by means of laboratory scale lysimeters.
68-69:056-019
FIXATION OF ATMOSPHERIC NITROGEN BY NON LEGUMES IN WET MOUNTAIN MEADOWS,
Porter, L. K., and Grable, A. R.
Agricultural Research Service, Fort Collins,  Colorado.
Agronomy Journal, Vol. 61, No. 3, p 521-523,  May-June 1969.  1 fig,  5 tab,  8  ref.
(See 68-69-.02K-020)
68-69:058-020
POLLUTION OF WATER FROM AGRICULTURAL SOURCES,
Harrold, Lloyd L.
Agricultural Research Service, Beltsville, Md.
The Ohio Engineer, Vol. 29, No. 4, p 10, April 1969,  3 ref.

Descriptors:  *Water pollution, *Agricultural chemicals, *Fertilizer, *Animal waste,
*Water pollution surces, Leaching, Streamflow, Erosion.
Identifiers:  *Farm chemicals, *Food production,  Automatic sampler.

USA became the world's foremost food quality and quantity producer by use of farm fer-
tilizer and other chemicals.  Phosphate fertilizer and dieldrin pesticide attach to
soil and do not dissolve readily in runoff water.  They become a significant part of
the pollution of water bodies only as soil is eroded by runoff water.  Nitrate ferti-
lizer pollutes surface and subsurface water bodies where excessive amounts are app-
lied and under high rates of rain and irrigation.  It is water soluble.  Beef cattle
feedlots of over 70,000 head in one unit raised the nitrate content of the soil 20
feet deep to a maximum of 5,000 pounds per acre.   Research is defining the involve-
ment of agriculture in the pollution problem by determining the fate of agri-chemi-
cals applied on farm lands and the effects of animal wastes.  It is also developing
cropping systems and other means for stabilizing pollutants from agricultural opera-
tions .
68-69-.05B-021
AGRICULTURAL POLLUTION OF WATER BODIES,
Edwards, William M., and Harrold, Lloyd L.
Agricultural Research Service, Washington, D.C.
The Ohio Journal of Science, Vol. 70, No. 1, p 50-56, January 1970.

Descriptors:  *Water pollution,*Farms, *Livestock, *Phosphorus, *Nitrates, *Pesti-
cides,  *Soil conservation, Runoff, Erosion, Percolation, Sediment, Waste.
Identifiers:  Lake Erie, Barnyard, Solids, Liquids.

Pollution of Ohio's water bodies is of growing public concern; industrial, urban, and
rural sources are becoming the subject of critical examination.  Rural sources are
soil sediment, plant nutrients, animal waste, and pesticides.  Pesticides and phos-
phorus are absorbed rapidly and strongly to soil particles.  Therefore, reductions in
sediment, phosphorus, and pesticide pollution are achieved by soil-erosion-control
farming practices.  More acres need to be brought under erosion-control practices.
Nitrates dissolve in water and are carried by surface flow to streams and lakes, and
by percolating water to underground aquifers.  Increases in the use of nitrogen fer-
tilizer, in evidence almost everywhere, could result in serious contamination of
water bodies, if soil enrichment greatly exceeds the crop demand.  Areas where large-
scale livestock and poultry production is concentrated are also potential sources of
serious pollution.  In Ohio, animal-waste pollution problems are being studied at
The Ohio State University, and movement of pollutants in surface and subsurface wat-
ers on drainage plots near Castalia are being studied by the Ohio Agricultural Res-
earch and Development Center and on agricultural watersheds by USDA Agricultural Res-
earch Service at Coshocton, Ohio.
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 68-69:05B-022
 AGRICULTURE'S CONTRIBUTION TO THE FERTILIZATION OF CANAL LAKE,
 Campbell, F. R.,  and Webber, L. R.
 Guelph University (Ontario), Dept of Soil Science.
 Journal of Soil and Water Conservation, Vol. 24, No.  4,  p 139-141,  August 1969.   2
 fig, 2 tab, 9 ref.

 Descriptors:  *Eutrophication, *Nutrients, *Water pollution sources,  *Agriculture,
 Nitrogen, Phosphorus, Fertilizers, Runoff, Farm wastes,  Productivity,  Aquatic  plants.
 Identifiers:  Canal Lake, Ontario.

 Water quality, weed growth, and nutrient loadings of  Canal Lake,  Ontario  were  studied
 between May and November 1968.  Relatively little nitrogen and  phosphorus are  contri-
 buted by the area's low-level agriculture.  Precipitation contributes  more nitrogen
 than streams.  Agriculture contributes about 0.15 Ib/acre, about  a  twentieth of  the
 yield from an equivalent nonfertilized area.  Most nitrogen probably  comes from  lake
 sediments, plants, and fixation of nitrogen in the lake.  About 84% of the phosphorus
 probably originates in a lake upstream of Canal Lake.  The agricultural yield  is  only
 about 63 Ib from 30,000 acres.  These contributions  of  nutrients are  negligible  con-
 sidering the total nutrients in the lake, the nutrient load of  the  streams, and other
 sources of nutrients.
 68-69:058-023
 MOVEMENT OF DDT AND NITRATES DURING GROUND-WATER RECHARGE,
 Scalf,  Marion R.,  Dunlap,  William J.,  McMillion, Leslie G.,  and  Keeley,  Jack  W.
 Robert  S. Kerr Water Research Center,  Ada,  Oklahoma.
 Water Resources Research,  Vol. 5, No.  5,  p  1041-1051,  October 1969.   10  fig,  1  tab,
 19 ref.

 Descriptors:   *Path of pollutants,  *Groundwater movement,  *DDT,  *Nitrates,  *Tracking
 techniques, Tracers, Water wells, Pumping,  Recharge, Discharge (Water),  Adsorption,
 Dispersion.
 Identifiers:   Aquifer tests, Pumping tests,  Ogallala aquifer.

 The Robert S. Kerr Water Research Center, U.S.  Department  of the Interior,  and  South-
 western  Great Plains Research Center,  U.S.  Department  of Agriculture,  recently  coop-
 erated  in a field  investigation of the fate  of  DDT  and nitrates  when  artificially
 recharged into the Ogallala aquifer.  The USDA  provided recharge and  observation wells
 and hydraulic equipment for injecting 350 gpm of water with  known concentrations of
 radioactive tracer, DDT, and nitrates. Following 10 days  of recharge, the  recharge
 well was pumped for 12 days at 500 gpm.   During recharge the nitrates moved to  the
 observation wells  essentially at the same rate  as the  recharge water,  and the DDT was
 absorbed to the aquifer material very near  the  recharge well.  During the pumping
 phase,  94% of both the recharge water and the nitrates was recovered.  The  concentra-
 tion of  DDT in the pumped  water was about 16 times  the recharged concentration  at
 initiation of pumping but  dropped below recharge concentration within one hour.  Ap-
 parently,  a major portion of the DDT introduced during recharge was not recovered dur-
 ing pumping but remained in the aquifer.
 68-69:05B-024
 PRELIMINARY  FIELD  STUDIES  USING  EARTH  RESISTIVITY MEASUREMENTS  FOR  DELINEATING ZONES
 OF CONTAMINATED  GROUND  WATER,
 Warner, D. L.
 Federal Water Pollution Control  Administration,  Ohio  Basin  Region.
 Groundwater, Vol.  7,  No. 1,  p  9-16,  January-February  1969.   7 fig,  10  ref.

 Descriptors:  *Ground water, Water quality,  *Water pollution, *Resistivity.
 Identifiers:  Long  Island, Texas.

 The measure of earth resistivity is  a  possible means  of detecting and  outlining zones
 of ground water  contamination where  a  resistivity contrast  exists between contamina-
 ted and uncontaminated  ground water.   As a preliminary evaluation of the use of elec-
 trical resistivity  for  defining  zones  of contaminated ground water, five sites on
Long Island and  three sites  in western Texas were  examined.  The surveys at three of
 the Long Island  sites and at one of  the western Texas sites were at least partially-
successful in their objectives.  The lack of success at the other sites is attributed
to the particular physical conditions  that existed.  Further effort to develop elec-
trical resistivity  for evaluating ground water quality variations is encouraged.


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68-69:05B-025
DISTRIBUTION OF CHLORINATED INSECTICIDES IN CULTIVATED SOIL,
Nash, R. G., and Woolson, E. A.
Agricultural Research Service, Beltsville, Maryland
Soil Science Society of America Proceedings, Vol. 32, No. 4, p 525-527, July-August
1968, 1 fig, 2 tab, 16 ref.
(See 68-69:05A-009)
68-69:058-026
FATE OF DDT AND NITRATE IN GROUNDWATER,
Scalf, M.R., Hauser, V.L., McMillion, L.G.,  Dunlap, W.J., and Keeley, J.W.
Robert S. Kerr Water Research Center, Ada, Oklahoma.
U.S. Department of the Interior, April, 1968.  46 p, 29 fig, 3 tab, 33 ref.

Descriptors:  *Groundwater,  Aquifers, Water storage, Water wells, Recharge, *Ni-
trates, Fertilizers, Water pollution sources. Water pollution. Water quality,  *DDT,
Insecticides, Organic pesticides, Pesticides, *Groundwater recharge, Waste water
(pollution).
Identifiers:  Ogallala Aquifer.

The Ogallala Aquifer was recharged at 348 gpm for a period of 10 days with water
taken from an irrigation well 2,280 feet from the recharge point.  Tritiated water,
nitrate, and p,p'-DDT were injected into the recharge stream at concentrations of
210vvc/ml, 24.46 mg/1, and 74 ppb, respectively.  The system was monitored by chemi-
cal analyses of samples taken at several observation wells with principal interest in
those located at 33, 66, and 150 ft from the injection well.  Water levels were moni-
tored continuously at 16 points located up to 1,000 ft from the recharge well.  Tri-
tiated water (H-jO)  can be used satisfactorily in groundwater studies to define the
movement of water and at the same time the three most important points resulting
from this study were:  1)  When present, nitrate pollution of the Ogallala is prob-
ably of more immediate concern than DDT because of its ability to move through the
aquifer; 2) A well, used for domestic purposes, should not be recharged with water
in which DDT is suspected becaused of the possible release of DDT contaminated aqui-
fer materical into water subsequently pumped from the well; 3) Considerable caution
must be used in extending this work to other pesticides because of the myriad of sol-
ubilities and the obviously varied adsorption characteristics encountered.
68-69:058-027
COLLECTED PAPERS REGARDING NITRATES IN AGRICULTURAL WASTE WATERS,
Federal Water Quality Administration, San Francisco, California, Series 13030ELY 12/69
U.S. Department of the Interior, December, 1969.  186 p, 55 fig, 37 tab, 66 ref.

Descriptors:  *Water pollution sources, *Return flow, *Nitrates, *Water pollution
control, *California, Drainage engineering, Drainage effects. Irrigation programs,
Irrigation systems, Water management  (Applied), Eutrophication, Path of pollutants,
Groundwater, Irrigation effects, Drainage water, Water quality, Excess water (Soils),
Return flow, Drainage programs.
Identifiers:  *San Luis Drain  (Calif), *San Joaquin Master Drain (Calif), *Central
Valley  (Calif) .

This is a collection of 11 papers dealing with the closely related topics of (a)
concentrations of nitrates occurring in subsurface agricultural waste waters,  (b)
the source of nitrates, and (c) possible methods for controlling or removing them.
The work all deals with subsurface agricultural waste waters of the San Joaquin
Valley in California, but much of the information may have general application.



68-69:058-028
CHARACTERISTICS AND POLLUTION PROBLEMS OF IRRIGATION RETURN FLOW,
Utah State University Foundation, Logan
U.S. Department of the Interior, 1968, Research Report No. 13.  43 p, 49 fig,  2 tab,
11 ref.
Descriptors:  * Irrigation practices, *Return flow, *Salinity, *Water pollution sources,
*Water quality control, Consumptive use, Water Pollution effects. Water reuse, Water
rights, Pesticide residue, Irrigation water.
Identifiers:  *Irrigation return flow, Research needs.
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An extensive review of the literature was made to assess the present state of sci-
entific knowledge and technology regarding water pollution problems associated with
the practice of irrigation and occurring in irrigation return flow.  Literature
dealing specifically with irrigation return flow was sparce.  Eighty percent of the
irrigated area of the U.S. was found to fall within an area in which the water de-
mands exceed or will exceed the supply by 1980.  Water quality changes during irri-
gation were found to be influenced by:  (1) biochemical action,  (2) erosion, (3)
evaporation and transpiration, (4) filtration, (5) heat transfer,  (6) ion exchange,
(7) leaching,  (8) precipitation, and (9) sorption and chelation.  The effect of
irrigation on the subsequent reuse of water by other users was considered.  Feasi-
bility studies have been conducted on treating and disposing of return water.  A
need was found for economic research explicitly concerned with irrigation return flow.
The legal aspects of reuse and water quality of irrigation return flows were ex-
amined and the recommendation made for more intensive study of the inseparable nature
of quality-quantity management in relation to institutional, economic, and legal
restrictions.  This article contains 245 references and a separate bibliography of
700 entries.
                                    130

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                                    SECTION XVIII


                       WATER QUALITY MANAGEMENT AND PROTECTION

                          EFFECTS OF POLLUTION (Group 05C)


68-69:050-001
AGRICULTURE'S EFFECT ON NITRATE POLLUTION OF GROUNDWATER,
Stewart, B. A., Viets, F. G., Jr., and Hutchinson, G. L.
Agricultural Research Service, Fort Collins, Colorado.
Journal of Soil and Water Conservation, Vol. 23, No. 1, p 13-15, January-February
1968.  1 fig, 1 tab, 8 ref.

Descriptors:  Groundwater, Pollutants, Nitrates, Fertilizers, Leaching, Water pollu-
tion sources. Nitrites, Water quality, Solid wastes, Agriculture, Alfalfa.
Identifiers:  Nitrogen balance, Methemoglobinemia, South Platte River, Feedlots,
Colorado.

Because of the danger of nitrates to humans and livestock and the stimulating effect
of nitrogen on the production of aquatic weeds, agriculture's use and production of
nitrogen forms are receiving much attention.  Increased uses of nitrogen fertilizers
and commercial and farm feedlot operations have prompted questions concerning their
contributions to groundwater pollution.  Fertilizers, feedlots and domestic sewage
effluent were believed to be the "new" sources of nitrate and nitrites in ground-
water.  Analysis of 129 core samples reaching from the soil surface to the water tab-
le or bedrock within, the South Platte River Valley in Colorado are given.  Research
needs regarding the effects of nitrogen fertilizers and feedlots on groundwater are
enumerated.
68-69.-05C-002
ON THE ECOLOGICAL CLASSIFICATION OF INLAND SALINE WATERS,
Ziemann, H.
Wasserwirtschaftsdirektion Werra-Gera-Unstrut, Erfurt, D.D.R.
Water Research, Vol. 2, No. 6, p 449-567, 1968.  2 fig, 2 tab, 25 ref.

Descriptors:  *Saline water, Ecology, Aquatic habitats, *Ecosystems, Ecotypes, *Bio-
logical communities, Halophytes, *Classification, Biology, Salts, *Diatoms.
Identifiers:  *Halobic index, *Alkalichloride, Poikilohalinity.

To find a biological basis for the classification of inland saline water, a quanti-
tative relationship between biological associations of diatom communities and salin-
ity in several inland saline waters were examined.  The sampling points in the riv-
ers Werra and Wipper were situated at stations where the water had different salt
contents.  Sampling for chemical examination took place daily, at several stations
weekly; the collection of biological samples was done once in every season.  The
reaction of the diatom communities is not dependent on the quantity of the salt con-
tent but on the physiological effect of the salinity which may be modified by the
combination of ions present.  Consequently, by an examination of the biological asso-
ciations, the waters may be ecologically characterized, independent of any knowledge
of the hydrographical factor.  On the basis of the biological effects of the salt
content, a classification of the inland saline waters of the alkalichloride type is
proposed, in which the classes are determined by the halobic index.
68-69:05C-003
RELATION OF AGRICULTURE TO GROUNDWATER POLLUTION: A REVIEW,
Robbins, J. W. D., and Kriz, G. J.
North Carolina State University, Raleigh, Dept of Biological and Agricultural Engi-
neering.
Transactions of the American Society of Agricultural Engineers, Vol. 12, No. 3, p 397
-403, May-June 1969.  2 tab, 97 ref.

Descriptors:  *Agricultural engineering, *Groundwater, *Pollutants, *Farm wastes.
Agriculture, Pollution abatement, Farm management, Waste water  (Pollution), Pesti-
cides, Insecticides, Herbicides, Bibliographies, Saline water, Irrigation water,
Waste water disposal, Waste disposal, Water pollution, Water pollution control.
Water pollution sources.
                                     131

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 Identifiers:  Groundwater quality, Pollution control.

 Groundwater is a water resource and a potential medium for receiving wastes.  Agri-
 cultural enterprises produce wastes that can lead to rapid degradation of  groundwater.
 Agricultural engineers are responsible for evaluating  agricultural  groundwater pollu-
 tion problems and recommending control and abatement measures.   The purpose of this
 paper is to orient agricultural engineers on groundwater pollution  problems caused by
 agricultural practices in three general areas:   (1)  evaluation  of groundwater as  a
 receiving medium for agricultural wastes; (2)  characterization  of the source of the
 pollutants; and (3)  delineation of the types of solutions needed for agricultural
 groundwater quality problems.  Agricultural groundwater pollutants  reviewed are
 animal wastes, fertilizers,  pesticides, plant residues,  and saline  waste water.
 68-69:05C-004
 EFFECT OF FATTY ALCOHOL ON CHANGE IN SOIL WATER DURING THE  SUMMER  FALLOW PERIOD,
 Brengle,  K.  G., and Mann,  K.  0.
 Colorado  State University,  Fort  Collins,  Department  of Agronomy.
 Journal of Soil and Water  Conservation, Vol.  24,  No.  1,  p 25,  26,  January-February
 1969.   1  tab, 6 ref.

 Descriptors:   *0ctadecanol, Fallowing,  *Soil  water,  *Summer, *Evaporation control,
 Alcohols, Colorado, Semiarid  climates,  Retardants, Rates of application,  Precipita-
 tion (Atmospheric), Water  loss.  Water storage,  Soil  surfaces,  Evaporation pans, Cul-
 tivation.
 Identifiers:   *Powder.

 A  study was  conducted  to determine whether fatty  alcohols would improve  efficiency
 of soil water storage  during  the  fallow period  under  semiarid  conditions  in south-
 eastern Colorado.   Octadecanol in powder  form was applied at rates of  0,  300, 600,
 and 900 pounds per  acre in  a  randomized block experiment with  five replications.  No
 significant differences in  soil water changes were noted in any of the three years
 during  which  the test was  conducted,  but  there  was a  trend  for less water loss with
 900 pounds of fatty alcohol per acre.   Surface  application  of  fatty alcohol at the
 rates used in this  study did  not  retard soil  water loss  enough to warrant its use in
 a  fallow  system.
68-69:05C-005
IMPACT OF AGRICULTURAL POLLUTANTS ON WATER USERS,
Law, J. P., Jr., and Bernard, H.
Robert S. Kerr Water Research Center, Ada, Oklahoma.
Transactions of the American Society of Agricultural Engineers, Vol. 13, No. 4, p 474-
478, July-August 1970.   3 tab,  23 ref.

Descriptors:  *Water pollution  sources, *Farm wastes, *Herbicides, *Water supply.
Recreation, *Agricultural chemicals, *Fertilizers, *Nitrates, *Phosphates, Saline
water, Water quality, Water pollution, Pesticides, Fishkill, Water sports, Wildlife.

The major sources of agriculturally associated water pollution activities include
animal wastes, irrigation return flows, fertilizers, and biocides.  The problems re-
sulting from these sources involve high BOD loadings, bacteria, and nutrient com-
pounds of nitrogen and phosphorus from animal wastes, increased salinity concentra-
tions from irrigation return flows, algae stimulating phosphorus and nitrogen in
fertilizers, and the lengthy residuals of chlorinated hydrocarbons and herbicides
common in many biocides.  Many  of the agricultural pollutants are eventually found in
public water supplies and cannot be economically removed with present technology.
Many western rivers contain both salinity and nitrate nitrogen at levels above stand-
ards established for potable water supplies, and others such as sulfates, chlorides,
and certain biocides are also found in high concentrations.  Aquatic life, fish, and
higher forms of wildlife are either being threatened by oxygen depletions associated
with overenrichment of algae mass or increased pesticide concentrations resulting
from accumulations in the food  chain.   Aesthetic and recreational use is impaired when
agricultural pollutants  include bacteria above limits of public safety or contribute
to excessive algal growth.  Agricultural use if often restricted by bacteria and sa-
linity in irrigation water.
                                     132

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68-69:05C-006
ADSORPTION OF PHOSPHORUS BY LAKE SEDIMENT,
Barter, R.D.
Connecticut Agricultural Experiment Station, New Haven.
Soil Science Society of America, Proceedings, Vol. 32, No. 4, p 514-518,  July-August
1968.  5 fig, 1 tab, 12 ref.

Descriptors:  *Phosphorus, *Eutrophication, *Algae, Sodium compounds, *Sediments.

The sediment of an eutrophic lake is capable of adsorbing a. large amount of phosphorus
from the water.  To study the sorption mechanism, between 0 and 2.2 mg P was added to
0.1-g sediment samples  (1:50 sediment-solution ratio).  After equilibrium had been
established, P remaining in solution was determined, and adsorbed P was extracted
with 0.5N NH4F and O.lN NaOH.  Whereas all P adsorbed into the NaOH- extractable
fraction appeared to occur as an iron phosphate, NH4F apparently extracted P bonded
by two different mechanisms.  When less than about 0.1 mg P was added, NH4F extract-
ed a tightly bonded form of P, probably occurring as an aluminum phosphate.  When
more than 0.1 mg P was added, additional P in a more loosely bonded form was adsorbed
into the NH4F-extractable fraction.  The loosely bonded P appeared to be independent
of Al content of the sediment, and could be removed by successive water extraction.
The capability of the sediment to adsorb considerable loosely bonded P means that
large influxes of P into the lake may be held temporarily and subsequently released
to growing plants and algae.
                                      133

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                                    SECTION  XIX


                       WATER QUALITY MANAGEMENT AND PROTECTION

                        WASTE TREATMENT PROCESSES  (Group 05D)


68-69:050-001
IRRIGATION WITH RECLAIMED WASTE WATER,
Hirsch, L.
Hirsch and Koptionak, Civil and Sanitary Engineers, San Diego, California.
Water and Waste Engineering, Vol. 6, No. 4,  p 58-60, April 1969.  1 fig, 2 tab, 4 ref.

Descriptors:  *Irrigation water, *Water utilization, *Water reuse, *Irrigation prac-
tices. Reclamation, Waste water, Water demand, *Reclaimed water.
Identifiers:  San Diego, California.

Reclaimed water will be a major element of total water management in  the future.  Re-
claimed wastewater involves the same general management problems as the use of pot-
able water for irrigation; namely, the interrelationship of water, soil, and plants.
These relationships were considered in view  of the sanitary, aesthetic, economic and
other practical factors governing the use of and reuse of water.  This article re-
views the various important aspects of the use of reclaimed wastewater for irrigation
purposes.
68-69:050-002
METHOD OF REMOVING NITRATES FROM WATER,
St. Amant, P. P., and Beck, L. A.
Robert S. Kerr Water Research Center, Ada, Oklahoma.
Agricultural and Food Chemistry, Vol. 18, No. 5, p  785-788, September-October  1970.
1 tab, 7 ref.

Descriptors:  *Nitrates, *Denitrification, *Algae,  Ponds, Drainage,  Bacteria,  Leach-
ing, Water quality, Tertiary treatment.
Identifiers:  *Algae stripping, San Francisco Bay System, San Joaquin Valley.

A 1967 Federal Water Pollution Control Administration report indicated that  serious
pollution problems would result if the tile drainage wastewater  from the  San Joaquin
Valley were discharged without treatment into the San Francisco  Bay  System.  The  re-
port further indicates that nitrogen in the nitrate  form  is the most  serious  potential
pollutant.  Nitrogen removal in ponds and filters by bacterial denitrification and
algae stripping was evaluated.  Algae stripping tests were run in  two ponds  of vary-
ing depths and it was found that detention time in  growth ponds  was  approximately 4
to 5 days during summer months and 15 days in winter months.  The  ponds were evalua-
ted by covering one with floating styrofoam and one uncovered.   A  90% nitrate-nitro-
gen removal was achieved in the covered pond with 10 day retention time.  Filter  de-
nitrification studies were performed in columns with a 6-ft media  depth.  The  major
variables studied were filter media and detention time which varied  from  ^ to  2 hrs.
Media size ranged from sand to 3-inch diameter gravels.  Greater than 90% removal of
the 20 mg/1 of nitrate-nitrogen was achieved at all detention times  studied.   Land
requirements for methods vary from 9000 acres to 150 acres and costs are  roughly
$25 to $30 per million gallons for each of the methods.
68-69:050-003
WATER REUSE: A TEXAS NECESSITY,
Fleming, R. D., and Jobes, H. D.
Texas Water Quality Board, Austin.
Journal of the Water Pollution Control Federation, Vol.  41, No.  9,  p  1564-1569,
September 1969.  2 fig, i tab.

Descriptors:  *Water reuse,  *Water demand, *Texas, Irrigation water treatment,  Eco-
nomics , Water allocation (Policy), Water management  (Applied).
Identifiers:  Texas Water Plan.

By the year 2020, Texas-'  •: =timati d ? 3 . ,r million people will need 12 mil  acre-ft of
water for nai:i;:ir n i -.nd indus'.rxa  u^-.-j, .= nd over 16 rail  acre-ft for  irrigation.
Because the a:'.::u:ii safe yi
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 development of other water sources is a necessity.  To plan for the future need,  sev-
 eral processes (desalinization, weather modifications, and water importation)  are
 being investigated.  To develop the importation idea,  the Texas Water Plan was ini-
 tiated in 1964.  This paper describes the main aspects of the plan (water reuse,
 tapping the Mississippi River, control of irrigation)  to help meet Texas' future
 needs.
 68-69:050-004
 CHEMICAL INTERACTIONS OF WASTEWATER IN A SOIL ENVIRONMENT,
 Hajek,  B.  F.
 Battelle-Northwest,  Richland,  Washington.
 Journal of Water Pollution Control Federation,  Vol.  41,  No.  10,  p 1775-1786,  October
 1969.   9 fig, 20 ref.

 Descriptors:  *Soil  disposal fields,  *Water chemistry,  *Wastewater (Pollution), Water
 reuse,  Biodegradation,  Permeability,  Soil  chemical properties,  Soil  physical  proper-
 ties, Filtration,  Clays, Groundwater  movement.
 Identifiers:  Soil-wastewater  relationships.

 The performance of soil as a wastewater disposal  and water reclamation  resource often
 can be  predicted from laboratory data which characterize wastewater,  soil,  and soil-
 wastewater relationships.   Many parameters must be studied to  assess  fully  the abil-
 ity of  soil to assimilate  wastewater.  Some of  the significant wastewater parameters
 are: pH, pollutant form and concentration,  concentration of  accompanying ions, tem-
 perature,  and volume disposal  characteristics.  Significant  soil  parameters are:
 bulk density, grain  size distribution,  mineral  composition,  exchange  capacity, and
 resident exchangeable cations.   Soil-wastewater relationships  are characterized by
 batch equilibrium  and dynamic  soil column  studies.  Either theoretical  or empirical
 approaches often can be applied to these data and used  to predict pollutant migra-
 tion rates and concentration distributions.
 68-69:050-005
 RATIONALE  OF  STANDARDS  FOR USE  OF  RECLAIMED  WATER,
 Foster,  Herbert  B.,  Jr.,  and  Jopling,  William  F.
 California State Dept.  of Public Health,  Berkeley.
 American Society of  Civil Engineers  Proceedings, Journal of  Sanitary Engineering
 Division,  Vol. 95, No.  SA3, Paper  No.  6609,  p  503-514, June  1969.  1 append.

 Descriptors:  *Water reuse, *Reclaimed water,  *Standards, *Water quality, Califor-
 nia, Waste water treatment, Tertiary treatment. Sewage treatment, Legislation, Regu-
 lation.
 Identifiers:  Reclaimed water standards  (Calif.).

 California has established standards for  reclaimed wastewater used for crop and land-
 scape irrigation and recreational  impoundments.  Insofar as  possible, the standards
 avoid the  use of specific quality  parameters in order to minimize monitoring require-
 ments which would be burdensome to small  operations.  The major exception is that,
 where a  disinfected  reclaimed wastewater  is  necessary, daily coliform bacteria analy-
 ses are  required.  This requirement  was one  of 4 major controversial points which are
 presented.  Other major points  raised  in  the development of  standards are specifica-
 tion of  operational  controls and practices in  the production and use of reclaimed
 wastewater, and  quality requirements for  the various uses.
68-69:050-006
CANNERY WASTE TREATMENT BY SPRAY IRRIGATION-RUNOFF,
Bendixen, T. W. , Hill, R. D., DuByne, F. T., and Robeck, G. G.
Robert A. Taft Sanitary Engineering Center, Cincinnati, Ohio, Cincinnati Water Res-
earch Lab.
Journal of the Water Pollution Control Federation, Vol. 41, Xo. 3, Part 1, p 385-391,
March 1969.  2 fig, 9 tab, 4 ref.

Descriptors:  *Canneries, *Industrial wastes, *Foods, *Tomatoes, Irrigation, Runoff,
Soil treatment, Grasslands, Wastewater treatment, Ohio, Chemical oxygen demand.
Identifiers:  ^Cannery waste, *Spray irrigation, Food processing.
                                      136

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A spray irrigation-runoff system is used to treat the wastes from a tomato-processing
plant.  The facility employs 5 plots containing a total of 165 acres.  The waste is
sprayed intermittently, 6 hrs on and 6 hrs off, at the top of 5% grassy slopes
and runoff collected after runs of 100 to 200 ft.  Tests show that 30 to 40% of
waste runs off, with the treatment efficiencies as follows:  COD, 95%; nitrogen, 93%;
phosphates, 84% and suspended solids, 97%.  Rainfall increases the runoff and de-
creases the efficiencies.
 68-69:050-007
 SEWAGE NUTRIENT REMOVAL BY A SHALLOW ALGAL STREAM,
 Hemens, J., and Mason, M. H.
 National Institute for Water Research of the South African Council for Scientific and
 Industrial Research, Pretoria, South Africa.
 Water Research, Vol. 2, No. 4, p 277-287, 1968.  5 fig, 1 tab, 28 ref.

 Descriptors:  *Algae, *Nitrogen, *Phosphorus, *Sewage effluent.
 Identifiers:  *Sewage nutrient removal.

 The use of algae ponds for removing nitrogen and phosphorus by assimilation from sec-
 ondary sewage effluent suffers from the disadvantage of inefficient light utilization
 by the dense algal cultures required and from the practical problem of economically
 removing the algae from suspension.  An experiment is described in which the pH in-
 crease resulting from algal photosynthesis in a shallow stream was used to remove
 phosphate by precipitation and nitrogen by assimilation and loss to the atmosphere
 as ammonia gas.  Association of precipitated phosphate with the algal cells produced
 a granular algal sediment easily removed by gravity settlement.  Removal of nitrogen
 and phosphate exceeded 90 percent in the warmer seasons, but at winter temperatures
 the efficiency was less, due to decrease in the elevation of pH value.  The method
 appears to have possible application for rural communities in equable climates where
 water reuse is desirable.
68-69:050-008
SELF-PURIFICATION IN AN OPEN DITCH,
Brink, Nils.
Uppsala University  (Sweden), Inst. of Limnology.
Water Research, Vol. 2, p 481-503, 1968.  19 fig, 5 tab, 19 ref.

Descriptors:  *0pen channels, *Self-purification, *Sewage, Flocculation, Organic
matter, Pollution, Abatement, Sedimentation, Waste water treatment.

The self-purification of running water after pollution by sewage was studied in a
ditch with a small water depth.  Both during winter (0-1 deg C) and summer, a high
degree of self-purification with respect to organic matter, nutrient salts, and bac-
teria was observed within a distance of 200-300 meters and during a time less than
4.5 hour.  Flocculation and sedimentation of organic and inorganic substances were
the predominant processes, especially in winter, but also ordinary breakdown and
building-up of organic matter and nitrification took place.  At high flow in spring
and autumn, deposited bottom sludge was carried away by the stream.  Such an oxida-
tion ditch, without disturbing drainage water from the surroundings during high flow,
is well suited as an alternative method of treating sewage.  A drop of up to about
90% in organic matter, nitrogen, and phosphorus over a distance of less than 300 met-
ers was observed in winter and summer.  The same was the case with coliform and gen-
eral heterotrophic bacteria to near 100%.  In spring and autumn, no such decreases
occurred.  An oxygen sag was found during winter and summer.  A balance between oxy-
gen and BODS was reached after 350 m.  In spring and autumn, no sag was found.
68-69:050-009
TREATMENT OF HIGH NITRATE WATERS,
St. Amant, Percy P., and McCarty, Perry L.
Federal Water Pollution Control Administration, Fresno, California.
American Water Works Association 89th Annual Conference, May 21, 1969, San Diego,
Calif.  18 p, 2 fig, 3 tab, 5 ref.

Descriptors:  *Waste water treatment, *Denitrification, *Anaerobic conditions, Aer-
obic conditions, Anaerobic bacteria, Filtration, Porous media, Aeration.
                                     137

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 Identifiers:  Anaerobic  filtration treatment.

 Biological denitrification was investigated as an economically feasible way to remove
 nitrates from waters to  control discharge of nutrients into bodies of water.  Pilot-
 plant studies conducted  to estimate chemical requirements, to evaluate anaerobic fil-
 ter media, and to determine the operating parameters of the anaerobic filtration pro-
 cess.  Biological denitrification in anaerobic filters is a reliable process for re-
 moving excess nitrates from water supplies.  An organic electron donor must be added
 to accomplish denitrification, and methanol has been found to be a satisfactory and
 inexpensive material for this purpose.  Use of one-inch gravel filter media and a de-
 tention time of one hour  is sufficient for 90% or greater removal of approximately
 20 mg/1 of nitrate-nitrogen in water with temperature of 12 deg C and above.  Costs,
 operating characteristics, and filter design data are tabulated.
 68-69:050-010
 DESALINATION OF  IRRIGATION  RETURN WATERS,
 Sword, B.R.
 Federal Water Pollution Control Administration, Fresno, California, San Joaquin Pro-
 ject.
 Water Pollution  Control Research Series, 13030 ELY, p 80-105, December, 1969.  14 fig,
 7 tab, 1 ref.

 Descriptors:  *Irrigation,  *Return  flow, Saline water, Desalination, Desalination
 processes. Impaired water quality,  *Electrodialysis, Osmosis, *Reverse osmosis, De-
 mineralization.
 Identifiers:  San Joaquin Valley, Total dissolved solids.

 Experiments were conducted  using drain tile waters  from a 400-acre field which had
 percolated through 5 to 9 feet of soil and contained a total dissolved solids  (TDS)
 concentration of from 2,500 to 8,000 mg/1.  The units tested were an Aerojet-General
 Reverse Osmosis Water Purifier and  an Ionics Electrodialysis Demineralizer.  The
 initial reverse osmosis stack was able to achieve over 90 percent TDS removal; how-
 ever, nitrate and boron removals averaged less than 27 percent.  The second stack
 removed 85 percent of the TDS with  negligible nitrate and boron removals.  The elec-
 trodialysis unit had an average TDS removal of 23 percent, with a maximum of 36 per-
 cent.  The cost for supplies and power for reverse osmosis  (Stack II) was $0.41 per
 thousand gallons of product.  The same costs for electrodialysis came to $0.15 per
 th.ousand  gallons of product, with  a comparable cost to reverse osmosis for a pro-
duct of 500 mg/1 TDS.  It is concluded that desalination of San Joaquin Valley tile
drainage water is technically feasible.
                                     138

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                                     SECTION XX


                       WATER QUALITY MANAGEMENT AND PROTECTION

                       ULTIMATE DISPOSAL OF WASTES (Group 05E)


68-69:05E-001
THE ANAEROBIC FILTER FOR THE DENITRIFICATION OF AGRICULTURAL SUBSURFACE DRAINAGE,
Tamblyn, T. A., and Sword, B. R.
Federal Water Pollution Control Administration, Fresno, California.
Proceedings of the 24th Industrail Waste Conference,  May 6,7, and 8, 1969,  Purdue
University, Lafayette, Indiana, p 1135-1150.  6 fig,  6 tab, 19 ref.

Descriptors:  *Denitrification, *Subsurface drainage, *Nitrate removal, Chemical
analysis.
Identifiers:  *Anaerobic filter, San Joaquin Valley.

This paper discusses one of the many investigations concerned with the "safe" dispos-
al of the up to 580,000 acre-feet (7.2xl08cu m) per year of saline water (subsurface
drainage).  Two basic techniques of nitrate removal are being investigated  in two
types of vessels:  deep ponds and anaerobic filters.   The operation of upflow anaero-
bic filters for efficient removal of nitrate-nitrogen from the  subsurface  agricultur-
al  drainage of the San Joaquin Valley by anaerobic denitrification is discussed.
Filters of three sizes (4, 8, and 36 inch diameter) were operated under field condi-
tions with hydraulic detention t^mes varying from 0.5 hr. to 6 hr.  Various media
were investigated, ranging from fine activated carbon to one-inch diameter  aggregate.
The required concentration of influent biodegradable organic carbon was also investi-
gated .
68-69:05E-002
DEGRADATION OF WASTEWATER ORGANICS IN SOIL,
Thomas, R. E., and Bendixen, T. W.
Robert A. Taft Sanitary Engineering Center, Cincinnati, Ohio.
Journal of the Water Pollution Control Federation, Vol. 41, No. 5, p 808-813, May
1969.  3 tab, 17 ref.

Descriptors:  Land disposal, Sewage treatment, Sludge, Soil fertility, Soil microbio-
logy, Soils.

Land disposal of wastewater sludge has become economically competitive with other
disposal methods and also can be beneficial to the land.  Soil microorganisms were
found to be able to digest much of the organic carbon contained in primary and sec-
ondary wastewater effluents according to a series of lysimeter studies.  Large vari-
ations in temperature, the loading rate, and the duration of dosing, had no effect on
the percentage of the organic carbon which was degraded.  A silica sand and a sandy
loam soil were dosed with a septic tank effluent and effluent from a high-rate trick-
ling filter.  Sludge loadings equivalent to 30/tons/yr/acre  (68 metric tons/yr/ha) of
organic carbon can be applied to sandy soils for extended periods with no detrimental
accumulation of organic residues.  This would equal 100 tons/yr/acre  (225 metric tons/
yr/ha) of dried digested sludge solids.
68-69:05E-003
DIGESTED SLUDGE DISPOSAL ON CROP LAND,
Hinesly, Thomas B., and Sosewitz, Ben.
Illinois University, Urbana, Dept of Agronomy.
Journal of the Water Pollution Control Federation, Vol. 41, No. 5, p 822-830, May 19
1969.  3 fig, 4 tab, 2 append.

Descriptors:  *Sludge disposal, *Crops, *Agriculture, *Irrigation, *Fertilizers,
Stabilization, Digestion, Sludge, Sludge digestion, Nutrients, Trace elements, Odors,
Infiltration,
Identifiers:  Chicago  (Illinois).

After an exhausted study to determine the best solids disposal solution, the Metropol-
itan sanitary District of Greater Chicago concluded that digestion followed by land
disposal could cope with Chicago's 1000 tons/day of sludge successfully at a cost of
                                     139

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 $20-$23/ton.  Research designed to determine groundwater contamination,  the effect  of
 heavy metals and crop irrigation parameters, was conducted.   At the Northeast  Agron-
 omy Research Center, digested sludge was applied by furrow irrigation at weekly  in-
 tervalson crop land planted with corn and kenaf.  The rates  were 1, 0.5, 0.25, and  0
 inches for a total of 6 weeks.   Average corn yield was 111.9,  114.2,  96.2,  and 66.3
 bushels per acre,  respectively.  While all the results are not in for the first  years
 research and demonstration projects on the 8 acre and 30 acre  test plots,  some obser-
 vations can be summarized.  (1) The crops responded favorably  to digested sludge.
 (2)  Offensive odors have not been a problem. (3) Flies were  never a problem.  (4) Fur-
 row irrigation is  preferred to  sprinkler irrigation.  (5)  Application of  nitrogen in
 amounts greater than those needed for crop production  will increase nitrate  level in
 drainage water.
 68-69:05E-004
 HYDROGEOLOGIC CONSIDERATIONS  IN LIQUID WASTE  DISPOSAL,
 Born,  S.  M.,  and Stephenson,  D. A.
 Wisconsin University,  Madison,  Dept of Geology.
 Journal of Soil  and  Water Conservation,  Vol.  24,  No.  2,  p  52-55, March-April  1969.
 2  fig, 7  ref.

 Descriptors:   *Waste water disposal,  *Irrigation,  *Sprinkler  irrigation,  Hydrogeology,
 Soils, Porosity,  Permeability,  Groundwater  movement,  Soil  water movement,  Infiltra-
 tion,  Percolation, Adsorption,  Filtration.
 Identifiers:   Spray  disposal.

 The  geohydrology of  liquid waste disposal by  irrigation  is reviewed.  Knowledge of
 geologic  conditions  is necessary for  spray  irrigation disposal of wastes.  The thick-
 ness,  nature, and distribution  of unconsolidated  surface deposits determine infiltra-
 tion,  adsorption storage,  and downward movement of waste water.  Infiltrometer tests
 may  be used in situ, or laboratory  examination of  samples  can yield quicker,  less
 accurate  information.   The condition  of  bedrock determines rate of water  movement and
 effectiveness of  filtration.  Flow  systems  must be studied to learn where  wastes will
 travel.
68-69:05E-005
A STUDY OF WASTEWATER IRRIGATION THROUGH COMPUTER  SIMULATION,
Cypra, K. J., Cowlishaw, W., and Bauer, W. J.
Bauer Engineering, Inc., Chicago,  Illinois.
Water Resources Bulletin, Vol. 6,  No.  6, p 935-943, November-December 1970.  2 tab,
4 fig, 3 ref.

Descriptors:  Model studies, *Wastewater treatment, Wastewater irrigation, *Water
quality, *Computer simulation, Planning, Lagoons.
Identifiers:  *Muskegon, Michigan, *Metropolitan water resources management.

Wastewater irrigation is a re-emerging method for  dealing with an area's wastewater,
particularly in Northern temperate climates in the U.S.  Muskegon, Michigan, typical
of a medium-sized northern urban area, is currently adopting wastewater irrigation to
meet its present and future wastewater treatment needs.  Design of a system for Mus-
kegon, Michigan must consider, among other things, the quantity of storage needed
prior to irrigation and the quality of water in the storage lagoons.  A computer sim-
ulated operation of the storage and irrigation aspects of the proposed wastewater
irrigation system resulted in a better understanding of storage requirements and cri-
tical quality parameters (particularly anaerobic conditions during spring break-up).
Further refinements of the model are expected to be of value in subsequent phases of
final system design.
                                     140

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                                     SECTION XXI


                       WATER QUALITY MANAGEMENT AND PROTECTION

                 WATER TREATMENT AND QUALITY ALTERATION  (Group 05F)


68-69:05F-001
TREATMENT OF HIGH NITRATE WATERS,
St. Amant, Percy P., and McCarty, Perry L.
Federal Water Pollution Control Administration, Fresno, California.
American Water Works Association, 89th Annual Conference, May 21, 1969, San Diego,
Calif.  18 p, 2 fig, 3 tab, 5 ref.
(See 68-69:050-009)
68-69:05F-002
BIOLOGICAL DENITRIFICATION OF WASTEWATERS BY ADDITION OF ORGANIC MATERIALS,
McCarty, P. L., Beck, L., and St. Amant, P.
Stanford University, Stanford, California, Dept of Civil Engineering.
Proceedings of the 24th Industrial Waste Conference, May 6,7,8, 1969, Purdue Univer-
sity, Lafayette, Indiana, p 1271-1285.  2 fig, 17 ref.

Descriptors:  *Denitrification, *0rganic material. Removal, *Eutrophication, *Meth-
anol, *Acetic acid, *Ethanol, *Acetone, *Sugar.

Biological denitrification has been frequently suggested as a method for the removal
of nitrate nitrogen from wastewaters when required for the control of eutrophication
in receiving waters.  This study was instigated by the California Department of Water
Resources to evaluate the effectiveness, required concentration, and cost of several
possible organic materials for denitrification.  Agricultural wastewater collected
from subsurface irrigation drains near the Agricultural Wastewater Treatment Center,
Firebaugh, California, was used for the studies.  The five commercial organic com-
pounds evaluated for denitrification were methanol, acetic acid, ethanol, acetone,
and sugar.  Initial studies were conducted with batch feed followed by periodic anal-
y s i s.  The most promising chemical at the completion of the batch experiment was
selected for evaluation in a semi-continuous treatment study.  Methanol was selected
as the most desirable organic chemical of the five studied for denitrification.
68-69--05F-003
REMOVAL OF NEMATODES BY RAPID SAND FILTRATION
Wei,  I.W., Engelbrecht, R.S., and Austin, J.G.
Illinois University, Urbana, Department of Civil Engineering
Journal of the Sanitary Engineering Division, ASCE, Vol. 95, No. SA1, p 1-16, Febru-
ary,  1969, 10 fig, 4 tab, 12 ref.

Descriptors:  *Filtrations,  *Water pollution, *Worms, Sands, *Nematodes, Sanitary
engineering, Filters.
Identifiers:  Rapid Sand Filters.

The results of a study on rapid sand filtration indicated that, with a low percent
nematode mobility, the removal of nematodes increased with decrease in sand size.  As
the percent mobility increased, the removal of nematodes decreased.  Also, as the
percent mobility increased,  the percent removal of nematodes by all sand sizes stud-
ied approached one another.   An evaluation of mobile nematodes in the influent and
effluent showed that most mobile nematodes could eventually pass through the sand bed
even  though some of them could be temporarily retained in the sand during the early
stages of the filtration process.  From a balance of nematodes entering and leaving
the system, it also appeared that mobile nematodes could dislodge the nematodes
which were initially retained in the sand bed.  Thus, these two phenomena resulted in
an overall decrease in removal of nematodes.  The effect of increased mobility, which
tended to decrease nematode removal, was more significant than the expected benefits
of using chemical pretreatment.
                                     141

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68-69.-05F-004
NEMATODE REMOVAL BY RAPID SAND FILTRATION,
Seth, A.K., George, M.G., Bewtra, J.K., and Sharma, V.P.
Central Public Health Engineering Research Institute, Chandrawal Water Works II,
Delhi, India.
Journal of the American  Water Works Association, Vol. 60, No. 8, p 962-968, August
1968.  14 fig, 2 tab, 8  ref.

Descriptors:  *Filtration, Water purification, Filters, Sands, *Water treatment,
Chlorination, Turbidity, Public health, Potable water, Nematodes, Soil microbiology.
Identifiers:  *Rapid sand filter, India.

Since normal doses of chlorine put into water supplies have no effect on nematodes,
a study was made to obtain the correlation between concentrations of neiratodcs in
filter influent and effluent while using different sizes of filter media at different
loading rates.  A pilot  plant with 4 filters containing sand with effective sizes of
9.45, 0.55, 0.65, 0.75 mm and uniformity coefficient of 1.35 was used in the study.
Filter runs were 24 hours in length with head losses and turbidity checks being made
every six hours.  Composite 6-hour samples from clarified water and filtrates were
tested for turbidity, worm population and temperature.  The conclusions were:  1) re-
moval of nematodes by rapid sand filtration is independent of the effective size of
the filter media between 0.45 and 0.75 mm; 2)  variation in the loading rate between
7.4 and 9.8 cm/min has very little effect on the efficiency of filters in removing
nematodes; 3)  about 55-60 percent of the mobile nematodes will pass through the fil-
ters operated as conventional rapid sand filters; 4)  nematodes in soil can be activa-
ted for such experiments.
                                    142

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                                     SECTION XXII


                       WATER QUALITY MANAGEMENT AND PROTECTION

                          WATER QUALITY CONTROL (Group 05G)


68-69:05G-001
DEGRADATION OF WATER QUALITY IN IRRIGATION RETURN FLOWS,
Law, J. P., Jr., Davidson, J. M., and Read, L. W.
Robert S. Kerr Water Research Center, Ada, Oklahoma.
Oklahoma State University, Agricultural Experiment Station Bulletin B-684, October
1970.  26 p, 7 fig, 6 tab, 27 ref, 1 append.
(See 68-69:02G-069)
68-69:05G-002
CHLORIDE CONTROL - ARKANSAS AND RED RIVER BASINS,
De Geer, M. W., and Ball, J. C.
U.S. Dept of the Army, Tulsa, Oklahoma, District Corps of Engineers.
Journal of the Sanitary Engineering Division, ASCE, Vol. 94, No. SAl,  p 117-128,
February 1968.  6 fig, 2 tab.

Descriptors:  *Water quality, *Water supply, *Sanitary engineering, Chlorides, Con-
trol systems, Experimentation, Injection.

Natural brine emissions are found to be the principal cause of water quality degrada-
tion in the Arkansas and Red River Basins.  The methods used to identify the brine
emission sources are discussed and the pollution problem is expressed in terms of
daily flows of thousands of tons of salt past major cities in the basins.  Alterna-
tive control solutions considered during the planning studies are discussed and some
selected control plans are presented.  The value of proposed control works is eval-
uated in terms of reduced chloride concentrations in major reservoirs.  Also present-
ed are proposals for experimental field work needed as a first step leading to final
design of control works.
68-69:05G-003
DRAIN INSTALLATION FOR NITRATE REDUCTION,
Willardson, L. S., Meek, B. D., Grass, L. B., Dickey, G. L., and Bailey, J. W.
Agricultural Research Service, Brawley, California.
Presented at the 1969 Winter Meeting, American Society of Agricultural Engineers,
December 9-12, 1969, Chicago, Illinois, Paper No. 69-734.  8 p, 2 fig, '2 tab.

Descriptors:  *Nitrate, *Drains, *Denitrification. Saturated soils, Water quality,
Water pollution sources, Anaerobic conditions, Path of pollutants, *Drainage water.
Drainage effects, Tile drainage, Soil water, Soil water movement.
Identifiers:  Panoche silty clay, *San Joaquin Valley.

The soil is a Panoche silty clay.  Six lateral lines of 6-inch concrete pipe were
installed in a grid pattern in the test field.  Two each of the individual lateral
lines were installed at three depths:  6 feet, 7^ feet, and 9 feet.  At the sump, an
elbow overflow outlet was installed on the main collector line which controlled the
ground water surface in the field at a depth of 6 feet.  Samples of the drain tile
effluent and atmosphere were taken at 3 locations along each drain.  At two locations
on each drain, 8 samples at different points on the exterior of the drain were taken.
Soil solution samples were taken near the drains and at the 1/3 point between the
drains at depths of 4^, 6, 7% and 9 feet.  At the 9-foot depth, the highest nitrate
readings are around the bottom of the drain.  The lh foot depth shows relatively high
nitrate all around the drain, while the 6-foot drain shows low nitrate content around
the top of the drain and high readings at the bottom.  Dilution and denitrification
were responsible for the reduced nitrate reading over the 6 and 9 foot drains.  The
electrical conductivity remained relatively constant and the nitrate level decreased
irt the outflow water from the total plot.  This change indicates that submergence of
the drains is resulting in denitrification in the field.
                                      143

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 68-69:05G-C04
 IRRIGATING WITH ANIMAL WASTE,
 Underwood, C.
 Soil Conservation Service, Hermiston, Oregon.
 Soil Conservation, p 81-82, November 1968.

 Descriptors:  *Farm wastes, *Irrigation, Groundwater,  *Water pollution,  *Irrigation
 practices, *Fertilizers,  *Waste disposal, Farm lagoons, Organic wastes,  Odor.

 The use of an irrigation system as a means of disposal of the animal waste from a
 hog-raising facility is described.  Effluent was pumped from the large pond directly
 into the sprinkling system.  Systematic management determines which field gets the
 liquid fertilizer.  The result showed that the sprinkler sewage disposal system fer-
 tilizes soil v/ithout oollution.
 58-63:05G-005
 SAN FRANCISCO BAY - DELTA WATER QUALITY CONTROL  PROGRAM,
 Walsh,  R.
 San Francisco Bay - Delta Water Quality Control  Program,  Sacramento, California.
 Journal of the Water Pollution. Control Federation,  Vol.  40,  No.  2,  p 241-251,  Feb-
 ruary 1968.

 Descriptors:   *Water resources,  *Water quality control.
 Identifiers:   Agricultural drainage,  *Water  quality program,  *San Francisco Bay,
 California,  San Joaquin Delta.

 San Francisco Bay and the Sacramento-San Joaquin area comprise one  of  the  most rapid-
 ly  developing areas in the country.   Existing and planned water  project developments
 together with agricultural drainage  waters all have an effect on the area.   The pro-
 gram,  now  being conducted by  the State of California and  to  be completed in 1969,
 will develop  the basic features  of a  comprehensive  plan  for  the  control of  water pol-
 lution  including a system for the collection,  reclamation, treatment,  and  disposal
 of  waste and  drainage water discharges.   This project, perhaps the  largest  and most
 comprehensive ever undertaken,  is unique in  several aspects  - area  size, complexity
 of  hydrological system,  diversity of  the beneficiaries,  and  methods of approach.
 68-69:05G-006
 DRAINAGE DESIGN  FOR MANAGING  SALINE  POLLUTANTS,
 winger, R. J., Jr.
 Bureau of Reclamation,  Denver, Colorado.
 Paper presented  at the  1969 Winter Meeting, American  Society of Agricultural Engin-
 eers, Chicago, Illinois,  Sherman House, Paper No.  69-735, December  9-12,  1969.   20 p,
 4 fig, 4 tab, 7  ref.

 Descriptors:  *Drainage,  *Drainage engineering,  Drainage practices,  Pollution, Water
 pollution, *Water pollution sources,  Salts, Drainage  systems, Tiles, Drainage water,
 Desalination, *Saline water.
 Identifiers:  *Donnan equation, Transient  equation.

 Management of the quality of  subsurface drain effluent  from irrigated  lands in the
 western United States can be  accomplished  by:   (1) constructing deep,  widely spaced
 subsurface pipe  drains  with pipe and  lined collectors terminating at a desalting
 plant; (2) constructing shallow, closely spaced  subsurface pipe drains which skim off
 the better quality ground water, leaving the more  saline ground water  in  storage,
 A drainage system design  using transient and steady state methods for  determining
 drain spacings when salinity  control  is considered is demonstrated  by  sample calcul-
 ations.
68-69:05G-007
RECOVERY OF DIFFERENTIALLY
Dancer, W, S., and Peterson, I.
Wisconsin "Jnivers i-cy, >'Tci ^so,:,
AgronOiT.v Journal, Vol. 61, No.
14 rsf.~
iCED  N03-N IN A SILT LOAM SOIL BY FIVE CROPS,
                                                3  tab,
                                     144

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Descriptors:  *Nitrogen, Crops, Corn, Beans, Tobacco, Loam.
Identifiers:  Nitrogen recovery.

Placement of NO3-N at soils depths of 8, 23, 38, 53, and 69 cm was accomplished by
an injection method with minimum disturbance to plant roots and to the soil profile.
Utilization of the differentially placed N03-N by five crops for two cropping seasons
indicated that these crops varied in their ability to recover the NO3-N.  Lima beans
 (Phaseolus lunatus L.) and green beans  (Phaseolus vulgaris L.) obtained most of their
N from the plow layer; while corn (Zea mays L.), tobacco (Nicotiana tabacum L.), and
red beets (Beta vulgaris L.) recovered NO3-N equally well from either the plow layer
or the subsoil.
68-69:050-008
PHOSPHORUS ADSORPTION SITES IN SOILS,
Harter, R. D.
Connecticut Agricultural Experiment Station, New Haven.
Soil Science Society of America Proceedings, Vol. 33, No. 4, p 630-632, July-August
1969.  3 tab, 10 ref.

Descriptors:  *Phosphorus, *Adsorption, Organic matter.
Identifiers:  NH4F and NaOH extractable phosphorus.

Regression analysis of phosphorus adsorption as a function of five soil characteris-
tics indicates that organic matter is important in the initial bonding of phosphorus
by soils.  It is,  therefore, proposed that phosphorus is initially bonded to anion
exchange sites on organic matter, and subsequently transformed into less soluble iron
and aluminum phosphates.
68-69:050-009
DENITRIFICATION AS A NITROGEN SINK IN LAKE MENDOTA, WISCONSIN,
Brezonik, P. L., and Lee, G. F.
Wisconsin University, Madison, Water Chemistry Laboratory.
Environmental Science & Technology, Vol. 2, No. 2, p 120-125, February 1968.  5 fig,
2 tab, 19 ref.

Descriptors:  *Denitrificatiori, Nitrates, Hypolimnion, Nitrogen cycle, Sediment,
Sinks, Nitrite, Ammonia.
Identifiers:  Lake Mendota.

The significance of denitrification as a sink in the nitrogen budget has been deter-
mined for Lake Mendota, Wis.  About 28,100 kg of nitrogen were lost from the lake
hypolimnion during the summer of 1966.  However, this relatively large amount repres-
ented only about 11% of the estimated total annual nitrogen input.  Denitrification
rates ranged from 8 to 26ug. of N per liter per day, while rates of nitrate reduction
(to ammonia and organic nitrogen) were found by 15N tracer techniques to range from
1.4 to 13.4yg. of N per liter per day in the hypolimnion of the lake.  Nitrate dep-
letion is more than an order of magnitude slower than oxygen depletion in the hypo-
limnion of Lake Mendota, and denitrification is probably not significant with respect
to respiration and catabolic processes in the lake hypolimnion.  There is some evid-
ence to indicate that dissolved nitrogen gas concentrations increase above those
expected on the basis of solubility as the result of denitrification.  Evaluation of
various nitrogen sinks for Lake Mendota has revealed that only about one third of the
estimated annual nitrogen input can be accounted for by currently evaluated sinks.
Sediment deposition probably accounts for most of the remaining two thirds.
68-69:05G-010
CHEMISTRY OF THE SAN JOAQUIN RIVER SYSTEM UNDER BASE FLOW CONDITIONS,
Nightingale, Harry I., and Behnke, Jerold J.
Agricultural Research Service, Fresno, California.
Journal of the American Water Works Association, Vol. 61, No. 8, p 382-386, August
1969.  5 fig, 7 ref.

Descriptors:  *Water quality, *Streamflow, *California, *Rivers, *Water chemistry,
Solutes, Groundwater, Water analysis, Irrigation water, Reservoirs, Springs, Lakes,
Precipitation (Atmospheric).
Identifiers:  *San Joaguin River.


                                     145

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 A water quality survey was made of the San Joaquin River,  California,  from its  origin
 in the Sierra Nevada to its entry into the east side of the San Joaquin Valley.   The
 basa flow of the river system is considerably modified by  dams, diversion tunnels,
 and pipelines for power projects, flood control,  and irrigation,  all  of which alter
 water quality.  From an irrigation standpoint, the quality of all the  waters  sampled
 within the San Joaquin River System (with the exception of West Chiquito Creek)  was
 excellent.  Although the salt content of the waters was quite low and  all the waters
 were derived from essentially granitic terrain, marked chemical differences did  exist
 between the source lakes and the river tributaries.  Mammoth Pool contained more dis-
 solved salts in somewhat different proportions than Huntington and Shaver Lakes.
 This difference is probably attributable to the fact that  some of the  higher  drainage
 areas associated with Mammoth Pool contain volcanic and metavolcanic  rocks and  assoc-
 iated thermal springs, whereas the drainage basins for the 2 other lakes are  composed
 almost exclusively of granitic material.   The chemical differences observed in  the
 tributary streams were generally attributed to differences in rock type in the  drain-
 age basin, groundwater return flow,  or unusual spring discharges.   There is approxi-
 mately an increase ir. salinity of 6.2  in the water of the  San Joaquin  River System
 from its  snow origin in the high Sierra Nevada to the eastern edge of  the San Joaquin
 Valley.   Most of the salinity increase takes place when the water infiltrates below
 the ground surface.   The displacement  of high quality lake waters by tunnels  and
 pipes for hydroelectric power generation has probably improved the chemistry  of  the
 river by  maintaining a firm base flow  composed of high quality water stored in  the
 Sierra Nevada lakes.
 68-69:05G-011
 COMMENTS ON  'RECREATION  BENEFITS FROM  WATER POLLUTION  CONTROL1,
 Burt, Oscar  R.
 Montana State University,  Bozeman.
 Water Resources  Research,  Vol.  5, No.  4,  p  905-907, August  1969.   1  fig,  6 ref.

 Descriptors:  *Kater pollution  control,  *Water pollution, *Benefits, Demand,  Sport
 fishing, Recreation demand,  Social values,  Recreation, Costs, Recreation  facilities,
 Prices, Cost-benefit analysis.
 Identifiers:  *Recreation  benefits,  *Consumer surplus. Willingness to pay. Marginal
 social value, Marginal social cost,  Gross benefits, Gross social value.

 The author comments on an  article and  note  by Joe B. Stevens pertaining to two alter-
 native measures  of benefits  associated with water pollution control  in a  sport fish-
 ery.  The purpose of this  note  is to present a third measure and to  show  that the
 other two measures are of  doubtful logical  validity.   The two measures of benefits
 attributable to  pollution  prevention by  Stevens he calls  (1) increased consumer sur-
 plus and (2) increased willingness to  pay.   The definition  of consumer surplus was
 taken from Marshal and willingness to  pay from Marglin.  Stevens'  analysis is applied
 to a graph showing two demand curves:  D  sub o corresponding to low  pollution and D
 sub 1 corresponding to high  pollution.   In  Stevens' note he is only  concerned with a
 procedure for measuring  the  gross benefits  of pollution control.   Stevens apparently
 felt it necessary to infer social value  from only D sub 0 and used D sub  1 only to
 determine quantity taken at  a zero price  under polluted conditions.  The  author feels
 that the discrepancy in benefits associated with pollution  control that Stevens found
 when using the two criteria  is  a result of  his dubious method of applying the two
 criteria.   The author then presents  a  generalized framework for analysis  which per-
 mits evaluation  of pollution control under  the assumption of optimum pricing.  Here,
 the difference in net values associated with polluted  and unpolluted water measures
 the social reward from pollution control  when recreation facilities  are optimally
 priced.  This net social value  could then be compared  with  the initial investment
 cost of pollution control  in some sort of benefit-cost framework.
68-69:05G-012
QUALITY OF SURFACE WATERS FOR IRRIGATION, WESTERN STATES-1961,
Love, S. K.
Geological Survey, Washington, D.C.
Geological Survey Water-supply Paper No. 1886, 1968.   154 p, 2 fig, 1 plate, 18 ref,
index.

Descriptors:  *Water quality, *Irrigation water, *Data collections, Streamflow,
Hydrologic data, Water chemistry.
Identifiers:  *Western US, Water quality data.
                                     146

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Water chemical quality and streamflow data of 1961 are compiled for 73 irrigation
network stations west of the Mississippi River.  Stations are listed with dates of
operation.  Each quality record includes station location, drainage area, a list of
available records, extreme values of specific conductance and sodium content, and
periodic records of runoff, silica, Ca, Mg, Na, K, bicarbonate, carbonate, sulfate,
Cl, F, nitrate, B, total dissolved solids, %Na, SAR, specific conductance, and pH.
68-69:050-013
REMOVAL OF SALINE WATER FROM AQUIFERS,
Carlson, E. J.
Bureau of Reclamation, Denver, Colo.  Office of Chief Engineer.  14 p, 4 fig,  1 tab,
16 ref.

Descriptors:  *Saline water-fresh-water interfaces, *Leaching, *Saline water systems,
*Groundwater movement, Drainage systems. Hydraulic models, Mathematical models,
Aquifers, Model studies, Drainage programs, Subsurface drainage, Water management
(Applied).
Identifiers;  Aquifer sweetening, Aquifer desalination.

Aquifer desalting was studied in a rectangular, glass-walled, sand-filled tank and in
a mathematical model.  Two types of aquifers were studied:   (1) a 1:40 scale,  two-
part aquifer  (course and fine sand) representing a vertical cross section through an
idealized protion of an irrigated valley; and  (2) a fine sand, single-part aquifer
used to evaluate a formula derived from the Ghyben-Herzberg principle for computing
depth to a saline-fresh water interface.  Salt water was flushed from the aquifers
into subsurface drains by applying fresh water to the surface.  Test results for
both aquifer types showed that tile drains placed near the ground surface will not
intercept and discharge surface-applied fresh water if all or part of the aquifer
contains salt water.  The fresh water displaces the salt water without appreciable
mixing and moves it into the drains.  A stable fresh-salt water interface is thereby
formed in the aquifer.   Reduced spacing of drains reduced the amount of salt water
that will be removed from the aquifer.  Progress of the tests was recorded in still
and timed-sequence motion pictures.
                                     147

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                                    SECTION XXIII
             WATER RESOURCES PLANNING - TECHNIQUES OF PLANNING (Group 06A)


68-69:06A-001
CONSTRUCTION OF PIPE DRAINS ON THE COLUMBIA BASIN PROJECT,
Monteith, J., and Myers, P. M.
Columbia Basin Project, Ephrata, Washington.
Paper presented at the 1968 Annual Meeting of the American Society of Agricultural
Engineers, Utah State University, Logan, Utah, June 18-21.  11 p.

Descriptors:  *Subsurface drains, *Investigation, *Design, *Inspection, Planning,
*Construction, Equipment.
Identifiers:  *Columbia Basin.

Experience in constructing 400 miles of subsurface pipe drains in seven years has
influenced present methods which are reported.  Nearly all of the work has been done
by contract.  Planning, investigation, design, preparation of specifications, con-
struction work, and inspection, with associated problems, are discussed.  Recently,
machinery has been used to dig a ten foot trench, lay pipe, and place gravel in one
pass, at a rate of as much as 2,000 feet in eight hours.
                                     149

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                                    SECTION XXIy


              WATER RESOURCES PLANNING - EVALUATION PROCESS  (Group 06B)


 68-69:06B-001
 TOWARDS ECONOMIC EVALUATION OF THE QUALITY OF WATER IN IRRIGATION,
 Yaron, Dan.
 Hebrew University, Jerusalem  (Israel), Dept of Agricultural Economics.
 Water For Peace, Vol. 6, p 749-757, 1967.  2 fig, 1 tab, 13 ref.

 Descriptors:  *Irrigation water, *Water quality control, Salt balance, Statistical
 methods, *Kater supply, *Water demand.
 Identifiers:  *Saline water systems, Evaluation.

 Water quality is controllable.  Therefore, the quantity and quality of water should
 be considered as economically meaningful parameters in water resource development or
 management decisions.  The effects of irrigation with saline water on crop yields
 are reviewed.  Next, a highly simplified economic model, which optimizes possible
 quantity - quality combinations within a framework of the supply and demand for irri-
 gation water is presented.  In making this model more realistic, the supply side is
 treated only indirectly but the distinction is explicitly made between the supply and
 demand.  The major portion of this paper deals with the evaluation of the quality of
 water in irrigation.

 68-69:068-002
 WATER QUALITY MANAGEMENT AND THE TIME PROFILE OF BENEFITS AND COSTS,
 Parker, D. S., and Crutchfield, J. A.
 Water Resources Engineers, Walnut Creek, California.
 Water Resources Research, Vol. 4, No. 2, p 233-246, April 1968.  9 fig, 2 tab, 6 ref.
 Descriptors:  *Demand, *Benefits, *Planning, *Water quality, Social aspects, Projects,
 Water pollution.

 Economists, in evaluating the long-term benefits in public works projects, have tra-
 ditionally held that long-term benefits will contribute very little to the total
 present worth of the benefits accrued over the life of the project.  It is shown,
 however, that the long-term social cost resulting from projects that cause water pol-
 lution cannot be neglected or assumed away in the host of practical cases where
 "amenity" demands for good water quality in a project's area of influence are signi-
 ficant.
68-69:06B-003
ECO-NTOMICS OF WATER-YIELD FOR SUGAR CANE,
Hogg, H. C., Davidson, J. R., and Chang, Jen-hu.
Hawaii University, Honolulu, Economic Research Service.
Journal of the Irrigation and Drainage Division, American Society of Civil Engineers,
Vol. 95, No. IR1, p 127-138, March 1969.  2 fig, 3 tab, 5 ref, 5 append.

Descriptors:  *Economics, *Irrigation, *Irrigation practices, *Water balance, *Water
demand, *Water yield, Evaporation pans, Management, Sugar cane.

An aggregate water deficiency model developed to isolate the relationship between
water and sugar cane yield is presented along with the empirical results of a speci-
fic application to plantation data.  The usefulness of the model as a basis for deal-
ing with a number of economic problems in irrigation management is demonstrated in
both a theoretical and empirical analysis.
68-69:068-004
INTERDISTRICT APPORTIONMENT OF FLOOD CONTROL COSTS,
Dague, R. R. , Baumann, E. R., and Morgan, P. E.
Iowa University, Iowa City, Dept of Civil Engineering.
Journal of the Irrigation and Drainage Division, American Society of Civil Engineers,
Vol. 94, No. IR4, p 441-454, December 1968.  6 fig, 1 tab, 2 ref.

Descriptors:  *Drainage, *Flood control, legislation, Cost-benefit analysis, Costs,
Assessments, Taxes.
Identifiers:  Litigation.


                                     151

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 Engineers are often called upon to apportion the costs of improvement works  among
 benefiting users.  In some cases,  the procedures for making the apportionment  are
 established.  In other cases,  legal statutes or engineering experience provide little
 information on apportionment procedures.   One such case is the  assessment  of the
 costs of flood-control improvements among several drainage districts  on a  river
 basin.  The Statutory Code of  the  State of Iowa (USA)  enables a part  of the  cost of
 flood control work in downstream districts to be assessed to upstream districts.  The
 Code states that the costs shall be assessed "...in porportion  to  the benefits der-
 ived."  How is the engineer to determine the relative benefits? The  writers consid-
 ered the physical characteristics  of the basin to arrive at a formulation  intended
 to reflect relative benefits.   The benefit factors are used to  calculate dollar
 assessments.  It is concluded  that the development of any "formula" for assessing
 drainage benefits must represent a balance between the theoretical and the practical,
 the tangible and the intangible, and previous experience.
 68-69:063-005
 TECHNOLOGICAL CHANGE AND THE ECONOMICS OF CONSERVATION,
 Rosenberry,  P. E.,  Daugherty, A.B.,  and Pavelis,  G.A.
 Economic Research Service,  Ames,  Iowa
 Journal  of Soil and Water Conservation, Vol.  23,  No.  4,  p 123-126,  July-August,  1968.
 10 ref.

 Descriptors:   Conservation,  *Economics,  Erosion  control,  Soil  conservation, Water
 conservation,  Adoption of practices,  Terraces,  Land resources,  Resources,  Land Man-
 agement,  Land farming.

 To achieve desired  levels of conservation,  economic principles  of allocating soil and
 water  resources over time must be considered  thoroughly,  along  with elements of  good
 engineering  practice,  in planning, designing  and  installing  conservation measures.
 Before this  goal is achieved,  certain challenges  must  be  met:   (1)  behavioral riddles
 of nonacceptance of apparently "profitable" conservation  farming systems must be
 solved;  (2)  the cost-benefit relationship of  specific  conservation  practices on  a re-
 gional and local level  must be established for  use  in  selecting appropriate measures;
 (3)  relationships between the total  social  benefits and  the  on-site,  short run bene-
 fits accruing  to the farmer must  be  established for use  in determining appropriate
 private-public cost sharing arrangements.   The  income  elasticities  of demand for food
 and  other  consumptive  goods puts  the  farmer in  a  cost-price  squeeze in relation  to
 industrial managers.  Technology  has  enabled  the  farmer  to substitute capital for
 labor  to  the  extent that it now represents  75 percent  of  all agricultural  resource in-
 puts.  In  general,  the  farm and ranch units have  increased in size  and thus the  empha-
 sis  is on  timeliness of operation, to larger  equipment and higher efficiencies.  Con-
 servation  measures  which improve  efficiencies are favored, while those which interrupt
 operations are disliked.
68-69:066-006
SIMULATION AND MODELING TECHNIQUES,
Young, D.F.
Iowa State University, Ames.
Transaction of the American Society of Agricultural Engineers, Vol. II, No. 4, p 590-
594, July-August, 1968.  5 fig, 11 ref.

Descriptors:  *Model studies, Simulation, Mathematical models. Design, Agricultural
Engineering, Dimensional analysis.

There is little doubt that the technique of simulation has been, and will continue to
be, applied successfully not only in research but also in design and analysis.  In
this paper the emphasis has been placed on the use of similar models because of their
widespread applicability in agricultural engineering.  Since the general theory is
well known, attention has been given to some of the problems that are known to arise
in the establishment of similarity parameters.  One of the greatest shortcomings
commonly encountered in the use of similar models is the incomplete analysis of the
problem, whereas no formal and well-defined procedure is used to establish the simi-
larity  requirements.  It is simply done on the basis of past experience and intui-
tion.  Frequently this leads to valid results because of a great accumulation of
experience, but also it can readily lead to erroneous results so that the application
of a standard formal procedure in the development of similarity requirements is rec-
ommended.  One of the major advantages of using dimensional analysis over other simu-
lation techniques is that the characteristic equations for the system do not have to


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be formally derived.  However, it is clear that a combination of theory and dimen-
sional analysis provides a more effective tool, even if the problem is to be studied
experimentally.
                                      153

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                                    SECTION XXV


                              WATER RESOURCES PLANNING
            COST ALLOCATION, COST SHARING, PRICING/REPAYMENT  (Group 06C)


68-69:06C-Q01
TOWARDS ECONOMIC EVALUATION OF THE QUALITY OF WATER IN IRRIGATION,
Yaron, Dan.
Hebrew University, Jerusalem (Israel), Dept of Agricultural Economics.
Water For Peace, Vol. 6, p 749-757, 1967.  2 fig, 1 tab, 13 ref.
(See 68-69:068-001)
                                      155

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                                     SECTION XXVI


          WATER RESOURCES PLANNING - WATER LAW AND INSTITUTIONS  (Group 06E)


 68-69:06E-001
 ECONOMIC  ISSUES IN CONTROLLING AGRICULTURAL POLLUTION,
 Taylor, G. C.
 Economic  Research Service, Washington, D.C.
 Paper presented at the American Agricultural Economics Association Meetings, Lexing-
 ton, Kentucky, August 19-20, 1969.  12 p, 14 ref.
 (See 68-69:05A-004)
68-69-.06E-002
WATER RIGHTS LITIGATION,
Taylor, Edward F.
City Attorney, Redlands, California.
Journal of the American Water Works Association, Vol. 58, No. 5, p 535-554, May 1966.
54 ref.

Descriptors:  Droughts, Water conservation, Interstate, Water supply, *Delaware River
Basin Commission, *Interstate compacts, State governments, Municipal water, *Water
permits, Riparian rights, Prior appropriation, Water pollution control, *Long-term
planning, Local governments.
Identifiers:  Water impasse. Model Water Use Act.

The drought that seized the Northeast in 1965, and which regularly seizes the West,
pointed out the need for water laws of national and regional scope, but, more impor-
tantly, for farsighted local plans.  The states of New York, New Jersey, and Delaware
launched long-range attacks on the problem of water supply and conservation through
the Delaware Basin Commission.  Local government's primary responsibility is to pro-
tect and develop water supplies.  Determining who has priority is the key in develop-
ing comprehensive rules to govern the use of water.  The Model Water Use Act is a
major aid in water-law revision as it incorporates the most workable provisions of
many state and local systems.  Western water law is the article's main topic.
68-69:06E-003
INSTITUTIONAL FACTORS AFFECTING LAND AND WATER DEVELOPMENT, LOWER RIO GRANDE VALLEY,
TEXAS,
Trock, Warren L.
Texas A&M University, College Station.
Water Resources Research, Vol. 5, No. 6, p 1364-1366, December 1969.  1 ref.

Descriptors:  *Water resources development, Institutional constraints, *Water law,
*Water rights, *Rio Grande, Land management, Water management  (Applied), Political
constraints.
Identifiers:  Lower Rio Grande Valley (Texas).

Among the many institutional factors that complicate land and water development in
the lower Rio Grande Valley are  (1) uncertainties in water rights,  (2) a prolifera-
tion of special districts,  (3) inappropriate water management policies among dist-
ricts, and  (4) numerous governmental entities involved in planning and administering
water resources.  It is recommended that the people of the valley urge and facilitate
an early adjudication of rights.  Improvements in irrigation and drainage could be
achieved by reorganizing the special districts.  A master district for the three-
county area may be a logical alternative to the many districts that now exist.  Reha-
bilitation of irrigation systems, including installation of water meters, will con-
tribute to the management of water supplies.
68-69:06E-004
LIAISON - KEY TO HIGHWAY AND AGRICULTURAL DRAINAGE PROGRAMS,
Drablos, Carroll J. W., and Jones, Benjamin A., Jr.
Illinois University, Urbana, Dept of Agricultural Engineering.
Journal of the Irrigation and Drainage Division, American Society of Civil Engineers,
Vol. 95, No. IR1, p 185-197, March 1969.  1 fig, 3 ref.
                                     157

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Descriptors:  *Agriculture, *Drainage, Legislation, Highways, Water laws.
Identifiers:  Liaison programs.

The solution of highway and agricultural drainage problems requires knowledge of
engineering practices and laws enacted by a particular jurisdiction.  However, many
of the problems that exist today have been the result of a lack of understanding or
willingness of the various interests to accept their legal responsibilities rather
than a lack of technical knowledge.  Communication or the exchange of ideas and in-
formation is essential so that the highway authority can acquaint the landowners with
proposed highway improvements at an early stage of planning and also learn their
plans for conservation and drainage improvements.  The development of a medium
of understanding between the various agencies, organizations, and landowners involved
is the first step in solving mutual problems.  Then the outlining of specific lines
of communication is necessary if each agency is to fulfill its responsibilities.
This paper presents some experience and suggests some procedures to follow to meet
the challenge for better solutions to highway and agricultural drainage problems.
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                                    SECTION XXVII


                     RESOURCES DATA - NETWORK DESIGN (Group 07A)


68-69:07A-001
CHEMICAL MEASUREMENT OF MEAN TEMPERATURE,
Lee, Richard, and Jones, E. B.
Pennsylvania State University, University Park.
Water Resources Bulletin, Vol. 4, No. 4, p 39-45, December 1968.   3 fig, 1 tab, 8 ref.

Descriptors:  *Temperature, *Hydrolysis, *Data collections, *Methodology, Analytical
techniques, Heat budget, Hydrologic aspects, Solar radiation, Evaporation, Consump-
tive use, Thermal pollution, Climatology, Pennsylvania, Irrigation.
Identifiers:  *Mean temperature, *Chemical method.

The significance of mean temperature to hydrology, methods of integrating temperature
over time, problems involved, and appropriate application areas for the chemical
mean temperature method are discussed.  A versatile methodology,  based on the temper-
ature dependence of sucrose hydrolysis, was tested in Pennsylvania.  The technique
permits low-cost mass sampling of air, water, and soil temperatures.  Because the
sensing elements are transparent, short-wave radiation effects are negligible.  In
field tests duplicate sensors yield repeatedly the same values plus or minus 0.02
deg C.  Data can be related directly to measurements obtained in standard climatolo-
gical networks.  The technique has good application in such hydrological studies as
evaporation, consumptive use, thermal pollution, and soil moisture in irrigation
practices.
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                                    SECTION XXVIII
                    RESOURCES DATA - DATA ACQUISITION  (Group 07B)


68-69:07B-001
PRELIMINARY FIELD STUDIES USING EARTH RESISTIVITY MEASUREMENTS FOR DELINEATING ZONES
OF CONTAMINATED GROUND WATER,
Warner, D. L.
Federal Water Pollution Control Administration, Ohio Basin Region.
Groundwater, Vol. 7, No. 1, p 9-16, January-February, 1969.  7 fig, 10 ref.
(See  68-69:05B-024)
68-69:07B-002
SOIL PREPARATION AND SAMPLING TECHNIQUES FOR STUDYING ION MOVEMENT,
Khasawneh, F. E., and Soileau, J. M.
Tennessee  Valley Authority, Muscle Shoals, Alabama
Soil Science Society of America Proceedings, Vol. 33, No. 3, p 476-477, May-June 1969.
3 fig, 5 ref.

Descriptors:  *Sampling, *Diffusion, *Ion transport.
Identifiers:  *Soil column sectioning, *Ped coatings.

Techniques are described for preparing and sampling soil columns and undisturbed soil
peds used for ion movement studies.tThese methods utilize a block of paraffin wax-
petrolatum jelly mixture to hold soil peds or to provide a cylindrical cavity for a
soil column.  A microtome and holder apparatus capable of holding the wax blocks
containing the soil is used for precision slicing at increments of 0.5 mm or more.
68-69:076-003
MEASURING THE HYDRAULIC POTENTIAL OF GROUND WATER WITH THE HYDRAULIC POTENTIAL PROBE,
Fokkens, B., and Weijenberg, J.
Land Improvement and Reclamation Company, De Bilt (Netherlands).
Journal of Hydrology, Vol. 6, No. 3, p 306-313, 1968.  3 fig, 2 tab, 2 ref.

Descriptors:  *Ground water, *Saturated soils, Time lag, Piezometers.
Identifiers:  *Potential probe.

The "potential probe," which was used by the authors during two years on a rather
large scale, is a new instrument to measure hydraulic potentials in saturated soils
without disturbing the soil profile.  A second advantage is that the basic time lag
of the apparatus is about 15 times shorter than that of normal one inch tube piezom-
eters.
68-69:076-004
HYDRAULIC CONDUCTIVITY MEASUREMENTS WITH A PRESSURE TRANSDUCER,
Overman, A. R., Peverly, J. H., and Miller, R. J.
Illinois University, Urbana, Dept of Agronomy.
Soil Science Society of America Proceedings, Vol. 32, No. 6, p 884-886, November-
December 1968.  2 fig, 6 ref.

Descriptors:  *Hydraulic conductivity, *Permeameters, *Permeability, Clay, Saturated
flow.

A rapid method for measuring hydraulic conductivities of materials in the range 10~6
to 10~10 cm/sec is described.  By using a pressure transducer as part of a decreasing
head permeameter, the time constant for measurement is reduced.  Only small volume
transfers of water are required.  An example is discussed to illustrate the method.
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 68-69:07B-005
 LEAF SAMPLER FOR RELATIVE WATER CONTENT MEASUREMENTS: DESIGN AND APPLICATION,
 Brown, R. W.
 Forest Service, Ogden, Utah, Intermountain Forest and Range Experiment Station.
 Agronomy Journal, Vol. 61, No. 4, p 644-647, July-August 1969.   3 fig, 11 ref.

 Descriptors:  *Evaporation, *Moisture content, *Plant tissue, *wilting,  *Turgidity.
 Identifiers:  *Leaf sampler, *Leaf cutter.

 A leaf sampler capable of holding eight samples has been designed and used for meas-
 uring the relative water content of plant tissues.  The precision-made leaf cutter
 and sample chambers permit the collection of leaf tissue disks  from leaves still
 attached to the plant.  After excision, tissue samples can be sealed immediately  in
 small vials within the sample chambers to prevent evaporative water loss.  Relative
 water content values of orchardgrass leaf samples obtained with the leaf sampler  were
 higher,  without exception, than were the values of similar samples obtained with  a
 cork borer.  However,  these differences were not significant until permanent wilting
 was approached.
 68-69:078-006
 A SIMPLE,  TENSION-FREE LYSIMETER,
 Jordan,  C.  F.
 Puerto Rico Nuclear Center,  Rio Piedras.
 Soil Science, Vol.  105,  No.  2,  p 81-86, 1968.   5  fig,  4  tab,  7  ref.

 Descriptors:   *Lysimeter,  Instrumentation,  Soil water. Water  loss,  *Percolation,
 Potassium,  Calcium, Soil types, *Podsols,  Soil  horizons.
 Identifiers:   Lakewood sand,  *"Zero-Tension"  lysimeter.

 The  "Zero-Tension"  lysimeter  can be installed  in  almost  any type  of  soil,  and  the
 problem  of  surface  tension,  common  to  many  lysimeters, is  eliminated.   It  was  tested
 in Lakewood sand, a podsol soil in  New Jersey.  When  light precipitation occurred,
 element  concentration in the  water  collected  from the A  and C horizons  was high, but
 the  B horizon and the underlying glauconite bearing bed  had soil  water  low in  element
 content.  During heavy storms,  however, element concentration in  water  from the B
 and  glauconite horizons  was higher  than from  the  A and C.  Potassium and calcium
 moved into  solution more rapidly than  iron  in  the podsol A horizon,  but iron moved
 out  more rapidly in the  B.  A large difference  in total  quantity  of  elements moving
 into A horizon lysimeters  occurred  between  two  areas  both  mapped  as  Lakewood sand.
 The  area with the greater  element movement  had  a  coarser texture, and the  A horizon
 extended deeper.
68-69:076-007
A RAPID METHOD OF  SOIL MOISTURE DETERMINATION,
Prihar, S. S., and Sandhu,  B.  S.
Punjab Agricultural University, Hissar,India.
Soil Science, Vol. 105, No.  3, p  142-144,  1968.   1  fig,  1 tab,  4 ref.

Descriptors:  *Soil moisture,  * Instrumentation, *Moisture content, Soil moisture
meters, Soil water, Soil density.
Identifiers:  Flask, Oven-dry  method.

A two-piece, 100-ml. glass  flask  has been  devised for rapid determination of soil
moisture.  The principle involved is the variable increase in the known volume of
liquid with the addition of  a  soil sample  of varying moisture contents.  The increase
in volume is measured in the calibrated tubular stopper  of the  flask.  Moisture con-
tents of ten soils were determined simultaneously using  oven-dry methods and the
flask method.  The soils ranged from fine  sand to clay loam with pH  from 5.3 to 8.5,
organic carbon from 0.2 to  0.8 percent and moisture contents varying from 2.6 to
36.8 percent.  Ninety percent  of  the values with  the flask are  within ±1.0 percent
moisture difference from the oven-dry values.  Regression equations  computed for
four soils and collectively  for all soils  are almost identical.  Therefore, the new
method can be said to be equally  applicable to the range of soils studied.
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68-69:078-008
A CORING DEVICE FOR UNCONSOLIDATED LAKE SEDIMENTS.
Schneider, R. F.
Southeast Water Laboratory, Athens, Georgia.
Water Resources Research, Vol. 5, No. 2, p 524-526, April 1969.  1 fig, 4 ref.

Descriptors:  *Lake soils, *Sediment, *Cores, Sampling, Lakes, Ponds, Pipes, Pistons.
Identifiers:  *Livingston corer.

A piston-type coring device for unconsolidated bottom deposits is described.  The
apparatus is a modification of the lightweight Livingstone corer.  The coring tube is
clear plastic, allowing visual examination of the core before extrusion, and the pis-
ton contains a vacuum release tube to prevent expansion of the cored material during
removal of the piston.  It is easily constructed, requiring no special machining, and
is therefore relatively inexpensive compared with other similar coring devices.
68-69:076-009
SOIL MOISTURE MEASUREMENT BY THE GAMMA TRANSMISSION METHOD,
Ryhiner, A. H., and Pankow, J.
Institute for Land and Water Management Research, Wageningen  (Netherlands).
Journal of Hydrology, Vol. 9, No. 2, p 194-205, October 1969.  8 fig, 2 tab, 3 ref.

Descriptors:  *Nuclear moisture meters, *Gamma rays, Calibrations, Soil moisture
">o.ters. Instrumentation, Density, Soil moisture, Soil water.
Identifiers:  Gamma-transmission soil moisture meters.

A discussion is given of the use of the gamma transmission method for the measurement
of soil moisture variations.  It is shown that a single calibration curve can be used
for very different soils.  An approach is presented for the determination of the
build-up factor of scattered radiation and for the instrumental resolution time.  It
appeared possible to calculate the systematic errors due to non-parall.elism of the
access tubes.
68-69:076-010
THE CALCULATION OF NON-PARALLELISM OF GAMMA ACCESS TUBES, USING SOIL SAMPLING DATA,
Rijtema, P. E.
Institute for Land and Water Management Research, Wageningen (Netherlands).
Journal of Hydrology, Vol. 9, Nol 2, p 206-212, October 1969.  3 tab, 1 ref.

Descriptors:  *Nuclear moisture meters, *Gamma rays, Calibrations, Soil moisture
meters, Instrumentation, Density, Soil moisture, Soil water.
Identifiers:  Gamma-ray moisture meters, Access tubes.

An equation has been derived to determine the errors due to non-parallelism of gamma
access tubes with the aid of soil sampling data, taken from the direct environment of
the measuring spot.  It is shown that the determination of the change in moisture
content is not very sensitive to errors due to non-parallelism.  When the absolute
values of moisture content are needed, it is always necessary to determine the errors
due to non-parallelism of the access tubes.
68-69:076-011
CALIBRATION AND EVALUATION OF A WIDE-RANGE GRAVIMETRIC METHOD FOR MEASURING MOISTURE
STRESS,
McQueen, Irel S., and Miller, Reuben F.
Geological Survey, Denver, Colorado.
Soil Science, Vol. 106, No. 3, p 225-231, 1968.  1 fig, 2 tab, 14 ref.

Descriptors:  *Soil moisture, *Soil moisture meters, *Moisture tension, Instrumenta-
tion, Calibrations, Soil water, Wettability, Hydrologic properties, Methodology.
Identifiers:  * Stress sensor, Filter paper, Filters.

A method of determining the soil moisture stress of field samples by sealing pieces
of filter paper into the sample container but not in contact with the sample is des-
cribed.  The samples and paper discs are allowed equilibrate at 20 deg C for at least
a week.  Samples must be handled with care; grain rearrangement changes moisture
                                      163

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 stress without change in water content.  After equilibration,  the paper is accurately
 and rapidly weighed.  Moisture stress may be computed from the moisture content of
 the filter paper or it may be obtained from a calibration plot.  The method is  effec-
 tive over a stress range of 0.001 to 1,500 bars.   The accuracy is as good as or
 better than that of other commonly used methods.
 68-69:07B-012
 PIEZOMETER DETECTION OF SATURATED INTERFLOW IN SOILS,
 Betson,  Roger P.,  Marius,  John B.,  and Joyce,  Robert T.
 Tennessee Valley Authority, Knoxville.
 Soil Science Society of America Proceedings, Vol.  32,  No,  4,  p 602-604,  July-August
 1968.  1 fig, 1 tab, 3 ref.

 Descriptors:  *Piezometers, Instrumentation, Soil  water,  *Saturated  flow,  Watershed
 hydrology.

 Piezometers were used as saturated  interflow detection devices in  a  study  of  partial
 watershed contribution to  storm runoff.   Saturated interflow  was detected  along  the
 AB-horizon interface in clay loam soils  with shallow A horizons.   The  results of the
 study showed that at least under some soil  conditions  piezometers  can  be useful  in
 determining the extent of  saturated flow within a  watershed.   The  occurrence  of  this
 flow will normally be confined to the shallow  A-horizon regions.
 68-69:078-013
 DESIGN  AND  PERFORMANCE  OF AN OSMOTIC  TENSIOMETER FOR MEASURING  CAPILLARY  POTENTIAL,
 Peck, A.  J., and  Rabbidge,  R.  M.
 Commonwealth Scientific and Industrial  Research  Organization, Canberra  (Australia),
 Division  of Plant Industry.
 Soil Science Society  of America Proceedings, Vol.  33, No.  2, p  196-202, March-April
 1969.   11 fig,  9  ref.

 Descriptors:   *Soil moisture,  *Soil water  movement,  Soil-water-plant relationships.
 Soil science,  Soil physics. Soil  chemistry,  Soil properties, Soil  investigations.
 Soil water, Unsaturated flow,  Diffusion, Evapotranspiration, Infiltration, Lysimeters,
 Moisture  tension.
 Identifiers:   *USSR.

 Soil moisture,  soil moisture movement,  and soil  properties  are  described  in a compre-
 hensive monograph of  the present  state  of  soil moisture  science in the USSR.  The
 approach  to soil  hydrologic studies in  the USSR  involves experiments and  observations
 under field conditions,  in  which  the  soil  layer  is studied  as a whole in  its native
 state.  The discussion  of  the  water properties of  soils  is  subdivided into porosity,
 water properties, sorption  of  water vapor,  sorption  of liquid water, suspended water,
 and free  gravitational  water.  The discussion of soil water movement and  soil-water-
 plant relationships is  subdivided into  thermodynamics, water motion, soil moisture
 and plants, and forms of soil  moisture.  The approaches  to  soil  moisture  studies in
 the US, Europe, and the  USSR are described and compared.
68-69:078-014
SIMULTANEOUS CYCLING OF PELTIER THERMOCOUPLE PSYCHROMETERS FOR RAPID WATER POTENTIAL
MEASUREMENTS,
Hoffman, G. J., Herkelrath, W. N., and Austin, R.  S.
U.S. Salinity Laboratory, Riverside, California.
Agronomy Journal, Vol. 61, No. 4, p 597-601, July-August 1969.  2 tab, 5 fig, 8 ref.

Descriptors:  * Instrumentation, *Soil moisture meters, *Soil water, *Hygrometry.
Identifiers:  *Thermocouple psychrometer scanner,  *Soil water potential, Leaf water
potential.


An automatic system was built to record the output from Peltier-effect thermocouple
psychrometers.  The system consists of a scanner, capacitors, voltmeter, and a rec-
order.  The scanner, built from inexpensive commercial components, is of solid-state
circuitry and contains oily one moving mechanism, a stepping relay.  The system aut-
omatically reads and stores the initial emf, cools as many as six psychrometers sim-
ultaneously, reads and stores the final emf, and heats the measuring junction of the
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psychrometers.  For a  30-second cooling period, six psychrometers can be read in 2h
minutes.  By adding a  stepping relay, as many as 150 psychrometers can be read in an
hour.  The standard deviations for recorded calibration outputs were ±0.04yv for soil
and  intact leaf thermocouple psychrometers.  Under actual experimental conditions,
the  values obtained with the automatic system were as accurate as measurements made
manually.
68-69:07B-015
INSTALLATION OF SOIL MOISTURE ACCESS TUBES IN ROCKY SOILS,
Richardson, Bland Z.
Forest Service, Logan, Utah, Intermountain Forest and Range Experiment Station.
Journal of Soil and Water Conservation, Vol. 21, No. 4, p 143-145, July-August 1966.
3 fig, 9 ref.

Descriptors:  *Drilling equipment, *Boreholes, *Moisture content, *Soil moisture met-
ers, *Radioactivity, Neutron absorption. Wells, Soil types. Rocks, Rock properties.
Rock excavation, Equipment.
Identifiers:  *Access tubes, Wagon drill, Hand-held drill.

Drilling holes for soil moisture access tubes in a rocky soil mantle can, without
proper planning and equipment, be the most costly, inefficient phase of soil moisture
studies that employ neutron scattering methods.  This paper discusses requirements
for drilling satisfactory access tube holes in rocky soils.  It describes and illus-
trates problems of drilling adequate holes with hand-held rock drills, tractor-mount-
ed drills, and crawler-mounted drills; and compares the efficiency and cost of these
methods.  The most satisfactory access tube holes can be obtained by using a wagon-
type rock drill mounted either on a tractor or self-propelled crawler.  Their cost
is only about one-sixth the cost of drilling holes with hand-held equipment.
68-69 .-07B-016
PIEZOMETER FOR MONITORING RAPIDLY CHANGING PORE PRESSURES IN SATURATED CLAYS,
Wolff, Roger G., and Olsen, Harold W.
U.S. Geological Survey, Washington, D.C.
Water Resources Research, Vol. 4, No. 4, p 839-843, August 1968.  6 fig, 5 ref.

Descriptors:  *Piezometers, *Instrumentation, *Piezometry, *Water yield, Observation
wells, Groundwater, Aquifers, Pressure, Aquicludes, Clays, Permeability.
Identifiers:  Pore-pressure changes. Imperial College Piezometer, In situ calibration.

A rapid response piezometer used for measuring dynamic changes in pore water press-
ures in saturated clays in response to pumping adjacent aquifers is described.  This
measurement is part of a technique developed to determine quantities of water that
are available from confining beds when pumping aquifers.  The instrument, a modifica-
tion of the Imperial College Piezometer, has rapid response, in situ calibration,
high sensitivity unaffected by total pressure, rugged shock-resistant construction,
and provision for continuous automatic recording.  The piezometer was tested in clay
loaded by a water column; test data are presented graphically.
68-69-.07B-017
A SENSOR FOR WATER FLUX IN SOIL. 2. 'LINE SOURCE1 INSTRUMENT,
Byrne, G. F., Drummond, J. E., and Rose, C. W.
CSIRO, Canberra, Australia, Division of Land Research.
Water Resources Research, Vol. 4, No. 3, p 607-611, June 1968.  3 fig, 2 ref.

Descriptors:  *Instrumentation, *Flowmeters, Current meters. Thermometers, Electronic
equipment. Research and development. Research equipment, Soil physics. Porous media.
Identifiers:  *Water flux sensor. Differential thermometers, Water flux.

Two sensors are described that measure the flux of water in soil, or the flux of
other fluids in any porous medium.  The electrical output of such instruments can be
of sufficient magnitude that a water flow velocity of .0001 cm/sec in soil is readily
measured.  The flow to be measured causes asymmetry in the temperature field gener-
ated by a line source of heat located centrally in the instrument.  The temperature
difference due to this asymmetry gives rise to the output of the instrument.  A theo-
retical analysis of the temperature field is given for boundary conditions appropri-
ate to each type of sensor.  Theoretical and experimental calibrations agreed closely


                                     165

-------
 when assumptions in the theory were realized experimentally.   The  analysis  was  used
 to elucidate design principles and their effect on instrument performance.
 68-69-.07B-018
 MEASURING SUBSURFACE SPRING FLOW WITH RADIOTRACERS,
 Galegar,  William C., and DeGeer, Myron W.
 Federal Water Pollution Control Administration,  Dallas,  Texas.
 American Society of Civil Engineers Proceedings,  Journal of  the  Sanitary  Engineering
 Division, Vol. 95,  No.  SA6,  Paper No.  6973,  p 1097-1103, December  1969.   4  fig,  2 ref.

 Descriptors:   *Tracers, *Tritium, *Groundwater movement, *Texas, *Springs,  Streamflow,
 Tracking techniques, Leakage,  Seepage, Water pollution sources,  Brines, Saline water
 systems,  Aquifers,  Karst, Groundwater.
 Identifiers:   Estelline Spring (Texas).

 A hydrostatic head  was  imposed on Estelline  Spring,  Texas to prevent  surface dis-
 charge  and subsequent natural  salt pollution of  the  Red  River.   This  paper  describes
 the  use of tritiated water as  a tracer to determine  the  rate of  subsurface  leakage
 of the  Spring, the  size of the Spring  cavern,  and the  location of  that area where
 subsurface leakage  returns to  the surface.   Other techniques using salt and organic
 dyes did not  prove  successful,  due largely to insensitivity  in detection  and probable
 losses  to adsorption and degradation.   The volume of the known spring chimney, inclu-
 ding that within the dike, amounts to  about  389,800  cu ft.   Knowing the amount of
 tracer  added  and the initial concentration of tracer after mixing,  it was determined
 that a  volume of 493,960 cu  ft existed.   From these  data,  it is  concluded that a
 second  chamber exists below  that which was previously  known; and its  volume amounts
 to about 104,000 cu ft.
 68-69:078-019
 A FAST-RESPONSE,  FIELD TENSIOMETER SYSTEM,
 Rice,  R.
 Agricultural Research  Service,  Phoenix,  Arizona
 Transactions of the  American Society of  Agricultural  Engineers,  Vol.  12,  No.  1, p  48-
 50,  1969.   5 fig,  5  ref.

 Descriptors:   Soil water  movement,  Evapotranspiration,  *Tensiometers,  * Instrumentation,
 Pressure measuring instruments,  *Soil water,  Moisture,  Tension.
 Identifiers:   Transducers,  Adelanto loam.

 The  multiple tensiometer  system connected  to  a  number of  tensiometers  through a hy-
 draulic scanning  valve performed satisfactorily for 10  months  under  field conditions.
 When the nylon tubing  from  the  porous ceramic was  exposed to the atmosphere,  consid-
 erable pressure fluctuations due to short-term  temperature changes occurred.  Shield-
 ing  the nylon  tubing with insulated foam-rubber tubing  eliminated these fluctuations.
 Response time  of  the tensiometers  in Adelanto loam was  sufficiently  fast  to obtain a
 reading within 2  minutes.   The  multiple-tensiometer system permits rapid-response
 measurement of a  number of  tensiometers  with  only  one transducer.  The  system should
 be of value wherever pressure-head  records  at a number  of points in  a dynamic soil-
 water system are  desired.
68-69:076-020
RADIOMETRIC METHODS OF MEASURING THE SOIL MOISTURE CONTENT,
Dimaksyan, A.M., and Glazkov, N.P.
State Hydrologic Institute  (Trudy GGI).
Soviet Hydrology:  Selected Papers, No. 4, p  333-351,  1969.  15 fig, 1 tab, 18 ref.
Translated from Trudy Gossudarstvennogo Gidrologicheskogo Instituta, No. 168, p 3-30,
1969.

Descriptors:  * Instrumentation, *Soil moisture meters, Soil moisture, Nuclear meters,
*Nuclear moisture meters, Moisture content, Moisture meters.
Identifiers:  *Gamma-method, *Neutron method, *Cadmium-ratio, Surface moisture meter,
Deep moisture meter.

A review is given of the currently available methods for making soil moisture deter-
minations.  The theory of the gamma-method of measuring soil moisture is given, along
with reasons for its limited application.  A detailed  analysis of the neutron method



                                     166

-------
for measuring soil moisture is given.  The use of the cadmium ratio in the calibra-
tion of a neutron moisture meter and moisture measurement is discussed.  Detail ac-
counts of investigations associated with the development of surface and deep moisture
meters using the cadmium ratio principles are given.
68-69:073-021
SEISMIC REFRACTION AND ELECTRICAL RESISTIVITY:  TOOLS IN GROUNDWATER EXPLORATION,
Sendlein, L. V. A.
Iowa State University, Ames, Dept of Earth Science
Transactions of the American Society of Agricultural Engineers, Vol. 11, No. 6 p 890-
892, 1968.  4 fig, 7 ref.

Descriptors:  Groundwater, Hydrogeology, Aquifer characteristics, Geology, Seismology,
Geophysics, Geologic mapping, Boreholes, Logging, Borehole geophysics, Resistivity,
Subsurface investigations, Aquifer.
Identifiers:  Geophone, Gish-Roony method.

The coordinated use of electrical resistivity and seismic refraction method in a geo-
logic investigation can produce a relatively inexpensive and accurate means of sub-
surface exploration.  Seismic methods measured the time of energy arrival at each
geophone.  These times were plotted and the breaks in the slope of the plotted lines
represented different energy paths.  The plot gave two types of information:  (1) the
seismic velocity of each layer, and  (2) the depth to refracting interfaces.  Seismic
velocity was correlated to rock type.  Electric resistivity measurements measured
changes in apparent resistivity which were plotted and compared to master curves to
determine true resistivity and thickness.  Bore hole methods were used, information
based on soil samples, drillers well logs and electric well logging data.  The co-
ordinated use of geophysics and geology applied to groundwater problems helps provide
maximum geologic information from minimum investment.
68-69:078-022
SOIL MOISTURE ESTIMATION BY THE NEUTRON METHOD IN BRITAIN  (A FURTHER REPORT),
Bell, J. P., and McCulloch, J. S. G.
Hydrological Research Unit, Wallingford, Berkshire, England.
Journal of Hydrology, Vol. 7, No. 4, p 415-433, 1969.  6 fig, 1 tab, 7 ref.

Descriptors:  Instrumentation, *Soil moisture, Nuclear meter, *Nuclear moisture
meters, Moisture content, *Soil moisture meters, Calibration.
Identifiers:  Britain.

Three different types of neutron scattering equipment for soil moisture measurement
in routine use in Britain were compared.  The purpose of the tests was to compare the
interface effects and the resolution of the different gauges.  Test profile No. 1
had a wet sand/air interface, while Test profile No. 2 had a dry soil/air interface;
the sand and soil were chosen to have contrasting values of dry bulk density to show
the effect of density on calibration.  Test profile No. 3 was a natural, undisturbed
soil profile.  The magnitude of the effects of soil chemistry and bulk density on
calibration curve are underestimated by many users.  A single general calibration
curve could be used, if the moisture differences are being measured over long periods
and if an accuracy of ±0.02 M.V.F. is acceptable, and if in most circumstances chemi-
cal and density effects could be ignored.
68-69:076-023
INSTRUMENTATION FOR MEASURING WATER POTENTIAL OF AN INTACT PLANT-SOIL SYSTEM,
Hoffman, G. J., and Splinter, W. E.
North Carolina State University, Raleigh.
Transactions of the American Society of Agricultural Engineers, Vol. 11, No. 1, p 38-
40, 1968 .   7 fig, 11 ref.

Descriptors:  Instrumentation, *Soil-water-plant relationships, Calibration, Hygro-
metry, Thermodynamics, Free energy.
Identifiers:  *Therrnocouple psychrometer, *Water potential.
                                     167

-------
Thermocouple psychrometer probes employing the Peltier effect and special instrumen-
tation were developed for measuring the water potential of an intact plant-soil sys-
tem for an extended period of time under precise temperature and relative humidity
control.  The thermocouple probe consisted of a measuring junction of 0.001-in. dia-
meter chromel and constantan wires inserted in a Teflon rod.  The equilibration or
sample volume of each probe was 0.005 cu in. over a leaf or soil measuring area of
0.043 sq in.  The probes were attached to intact leaves with epoxy cement or inserted
into an auger hole in the soil.  Various concentrations of salt solutions were used
for calibrating the probes.  A test chamber was constructed in which temperature
could be controlled within 0.001 C by utilizing several intermediate control steps to
permit accurate water-potential measurements.  Absolute temperature was measured with-
in 0.001 C using a calibrated resistance thermometer and a six-dial potentiometer.
                                     163

-------
                                   SECTION XXIX


         RESOURCES DATA - EVALUATION, PROCESSING AND PUBLICATION ( Group 07C)


68-69 :07C-001
COMPUTER METHODS FOR TRANSIENT ANALYSIS OF WATER-TABLE AQUIFERS,
Taylor, George S., and Luthin, James N.
California University, Davis.
Water Resources Research, Vol. 5, No. 1, p 144-152, February 1969.  4 fig, 11 ref.

Descriptors:  *Drawdown, *Mathematical models, *Digital computers, Groundwater move-
ment, Saturated flow, Unsaturated flow. Water level fluctuations, Theis equation,
Thiems equation, Dupuit-Forchheimer theory.
Identifiers:  Pumping tests, Aquifer tests, Drawdown analysis.

Computer methods for calculating drawdown in unconfined aquifers are discussed.  Sol-
utions for the saturated and unsaturated flow of water to wells may be obtained sim-
ultaneously.  The method solves the basic flow equations with given boundary condit-
ions, taking into account the properties of the unsaturated zone and the contribution
of vertical flow.  The basic equations are listed and expressed in cylindrical coor-
dinates.  The steps to be used in computer solution by numerical analysis are listed
and discussed.
                                      169

-------
                                    SECTION XXX


                     ENGINEERING WORKS - STRUCTURES (Group 08A)


68-69:08A-001
CARBONATE SCALE IN ROMAN AND MODERN CANALS IN THE JORDAN VALLEY,
Underbill, H. W.
Food and Agriculture Organization of the United Nations, Iraklion (Crete).
Journal of Hydrology, Vol. 7, No. 4, p 389-403, April 1969.  4 fig,  2 tab, 15 ref.

Descriptors:  *Scaling, *Canals, *Calcium carbonate, Hardness (Water), Irrigation
water, Spring waters, Arid lands, Irrigation canals.
Identifiers:  *Jordan.

Problems of loss of capacity of canals and pipelines carrying waters heavily charged
with carbonates are not new; examples are described from classical and modern times
in the Jordan Valley.  An outline of the chemistry of carbonates in ground water is
followed by a discussion of the chemical analyses of two springs in west Jordan.
Different indices of calcium carbonate saturation are examined;  as none of these ind-
icates the delayed properties of such waters, the addition of an'aerated saturation
index1 is proposed.  The rate of scale formation in the modern Ain Feseyl canal is
estimated from chemical analyses.  The relation between scale precipitation in man-
made works and its formation under natural conditions is noted,  and a historical foot-
note on the probable origin of the scale-filled Roman canal at Ain Feseyl is included.
                                     171

-------
                                     SECTION XXXI

                                     AUTHOR INDEX
Abuamin, H.
     68-69:021-001
Ball, J. C.
     68-69:050-002
Bishop, A. A.
     68-69:02F-040
Abu-Shakra, S.
     68-69:03F-009

Acharya, C. L.
     68-69:02D-011

Acherman, Edward A.
     68-69:030-001

Adams, J. E.
     68-69 :02D-006

Ahmad, N.
     68-69:020-061

Akhtar, M.
     68-69:03F-009

Allen, R. R.
     68-69:02F-033

Allison, S. V.
     68-69.-03F-028

Allman, David W.
     68-69:04A-010

Amer, F.
     68-69:021-001

Amerman, C. R.
     68-69:02E-009
     68-69:02G-053

Anderson, W. D.
     68-69:021-011

Atkinson, K.
     68-69:02J-014

Austin, J. G.
     68-69:05F-003
Baron, V. A.
     68-69:02G-049

Bartholic, J. G.
     68-69:021-013

Bassett, Day L.
     68-69.-03F-019

Bauer, W. J.
     68-69:05E-005

Baumann, E.  R.
     68-69:068-004

Beall, M. L. , Jr.
     68-69:02K-003

Beaumont, P.
     68-69:02J-014

Beck, L. A.
     68-69:058-018
     68-69:05D-002
     68-69:05F-002

Beer, Craig E.
     68-69:02G-054

Behnke, Jerold J.
     68-69:020-002
     68-69:05G-010

Bell, J. P.
     68-69:07B-022

Bendixen, T. W.
     68-69:050-006
     68-69:05E-002

Benz, L. C.
     68-69:02G-032
Black, T. A.
     68-69:02D-003
     68-69 :02G-009

Bloomfield,  C.
     68-69:02K-012

Boawn, L. C.
     68-69:05B-013

Boersma, L.
     68-69:02G-005
     68-69:02G-037
     68-69:02G-048
     68-69:02K-018
Bokhari, 5. M. H.
     68-69--02F-035

Bondurant, J. A.
     68-69:02E-002

Born, S. M.
     68-69:05E-004

Bouwer,  Herman
     68-69 :02G-030
     68-69:02G-047
     68-69:03F-020
     68-69 :04A-004

Bower, Charles A.
     68-69.-02G-021
     68-69:02F-025
     68-69 :03C-003

Brand, E. W.
     68-69:02F-005

Branscheid, Volker 0.
     68-69:04A-003
Austin, R. S.
     68-69:078-014
Bernard, H.
     68-69:050-005
Bray,  D. W.
     68-69:03F-009
Bachmat, Yehuda
     68-69:02F-027
Berstein, L.
     68-69:02I-019
Brengle, K. G.
     68-69:05C-004
Baier, W.
     68-69:020-005

Bailey, J. W.
     68-69:02F-016
     68-69:05G-003

Baird, Ralph W.
     68-69:02E-007
     68-69:02J-008

Baldwin, C. S.
     68-69:02K-005
Betson, Roger P.
     63-69 :07B-012

Seville, B.  C.
     68-69:02F-046

Bewtra, J. K.
     68-69:05F-004

Bianchi, W.  C.
     68-69:02G-028

Biggar, J. W.
     68-69:020-007
     68-69.-02G-060
Bresler, E.
     68-69:02F-004

Brezonik, P. L.
     68-69 :05G-009

Brink, Nils
     68-69:050-008

Britt, Clarence S.
     68-69.-05B-006

Brooks, Royal H.
     68-69:02F-022
     68-69 .-02G-005
                                      173

-------
 Brown,  M.  J.
      68-69:02G-066
                                Chapman, A. L.
                                     68-69:02D-010
                                Dale,  Robert  F.
                                     68-69:020-020
 Brown,  R.  G.
      68-69:02F-008

 Browii,  R.  W.
      68-69:07B-005

 Browning,  J.  E.
      68-69:020-027

 Brutsaert,  Wilfried
      68-69:020-033
      68-69:020-036
      68-69:02G-045

 Burcar,  P.  J.
      68-69:02K-010

 Bruce,  R.  R.
      68-69:021-009

 Burman,  R.  D.
      68-69:020-023

 Burnett, E.
      68-69:020-006

 Burt, E. 0.
      68-69:020-027

 Burt, Oscar R.
      68-69:05G-011

 Burwell, R. E.
      68-69:020-015
      68-69:020-059

 Butcher, William S.
      68-69:03F-013

 Bybordi, M.
      68-69:020-022
      68-69:020-064

 Byrne, G. F.
      68-69:078-017

Campbell, F. R.
      68-69:05B-022
 Carlson, E. J.
      68-69:050-013
       -69:02J-003
         "  " -017
Carter, C.
      66-69	
      68-69:02J
Carreker, J. R.
      68-69:02J-017

Gary, J. W.
      68-69:021-022

Cassel, D. K.
      68-69:020-007
      68-69:020-060

Champlin, J. B. F.
      68-69:02F-007
      68-69:02K-001

Changnon, Stanley A., Jr.
      68-69:04A-007

Chang, Jen-hu
      68-69:06B-003
 Chauhan,  H.  S.
      68-69:04A-011

 Chaudhrv,  G.  H.
      68-69:02K-019

 Chen,  L.  H.
      68-69:020-029

 Chesters,  G.
      68-69:05A-005

 Childs, E. C.
      68-69:02G-022

 Chirkov,  Yu.  I.
      68-69:02G-018

 Christiansen, Jerald  E.
      68-69:020-024

 Christiansen, A. G.
      68-69:05B-005

 Cline, J. N.
      68-69 :02D-014

 Coffey, Philip J.
      68-69:03A-001

 Coltharp, G. B.
      68-69:020-019

 Connell, W. E.
      68-69 :02K-002

 Corey, Arthur T.
     68-69 :02F-022

 Corey, J. C.
     68-69:020-067

 Cornelius, D. R.
     68-69 :02I-021

 Cossens, G. G.
     68-69 :02G-004

 Ccutts, J. R. H.
     68-69 :02J-005
     68-69 :02J-006

 Crutchfield, J.A.
     68-69 :063-002

 Cowan, I. R.
     68-69 :02G-014

 Cowlishaw, W.
     68;69 :05E-005

Cypra, K. J.
     68-69:05E-005

Dague, R. R.
     68-69:063-004

Daishev,  T. I.
     68-69:02F-006
Dalton, F. N.
      68-69:020-009

Dancer, W. S.
      68-69:050-007

Daugherty, A. D.
      68-69:068-005

Davenport, David C.
      68-69:020-025

Davidson, J. M.
      68-69:02G-044
      68-69:02G-069

Davidson, J. R.
      68-69:06B-003

DeBacker, L. W.
      68-69:020-037

Dendy, Farris E.
      68-69:02J-015

d'Errico, T. R.
      68-69:02F-028

Day, A. D.
      68-69:03C-001

Donovan, T.  J,
      68-69:030-001

De Datta, S. K.
      68-69:021-010

De Geer, M.  W.
      68-69:050-002
      68-69:078-018

De Vries,  J.
     68-69 :02G-068

Dickens, W.  L.
      68-69:02I-011
     68-69:021-012

Dickey, G. L.
     68-69:02F-016
     68-69:05G-003

Dimaksyan, A. M.
     68-69:078-020

Donnelly,  E. D.
     68-69:03F-008

Doody, James J.
     68-69 :02F-036

Doss, B. D.
     68-69 :02I-005

Dos Santos,  A. G., Jr.
     68-69:04A-002

Doty, C. W.
     68-69:02E-00'1

-------
Dougherty, C. T.
     68-69:03F-023
Endrodi, Bariella
      68-69:02I-020
Foster, Herbert B., Jr.
     68-69:050-005
Drablos, Carroll J. W.
     68-69 :06E-004
Engelbrecht, R. S.
      68-69:05F-003
Foster, Richard L.
     68-69 :02J-011
Dracup, John A.
     68-69:02D-013
Epstein, E.
      68-69:02E-005
Fouss, J. L.
     68-69:02F-003
Dragoun, Frank J.
     68-69:02E-006
     68-69 :02J-010

Drake, R. L.
     68-69--02F-020

Drew, M. C.
     68-69:02K-013

Drost, Walter
     68-69:02F-034

Drummond, J. E.
     68-69 :07B-017

DuByne, F. T.
     68-69:050-006

Dumm, Lee D.
     68-69:02G-023

Dunin, F. X.
     68-69;02n-016
     68-69:02F-026

Dunlap, William J.
     68-69:05B-023
     68-69:056-026

Dusek, D. A.
     68-69:02G-026

Eck, H. V.
     68-69:021-007

Edwards, D. M.
     68-69:05B-014

Edwards, W. M.
     68-69:02G-063
     68-69:02G-070
     68-69:056-021

Ehlers, P- L.
     68-69 :02I-017

Eichholz, G. G.
     68-69:02F-007
     68-69:02K-001

Ekstein, J.
     68-69:02F-044

Ellis, W. R.
     68-69:02F-038

Elnagger, Hameed
     68-69:02F-021

Elrick, D. E.
     68-69.-02G-055
Erickson, A. E.
      68-69:02G-025

Enfield, C. G.
      68-69:02G-052

England, C. B.
      68-69:04D-001

Erie, L. J.
      68-69:021-002
      68-69:03F-014

Esmaili, Houshang
      68-69:02F-041

Etinger-Tulczynska, R.
      68-69 .-02K-014

Evans, D. D.
      68-69:02G-041
      68-69:02G-052
      68-69 .-02G-062

Fansey, N. R.
      68-69:02F-003

Parish, C. A.
      68-69:03F-029

Fausey, N. R.
      68-69:02G-012

Fedorov, S. F.
      68-69:020-012

Fernandez, Pedro
      68-69:020-039

Fischbach, Paul E.
      68-69:03F-001
      68-69:053-014

Fisher, H. D.
      68-69:021-022

Fitzpatrick, E. A.
      68-69:02D-015
      68-69:020-026

Fleming, R. D.
      68-69:050-003

Florian, R. L.
      68-69:020-008

Fokkens, B.
      68-69:C7B-003

Ford, H. W.
      68-69:02F-046

Foster, G. R.
      68-69.-02G-013

      175
Freeze, R. Allan
     68-69:02F-030

Fredricksen, R. L.
     68-69:05A-002

French, O. F.
     68-69:021-002

Frink,  C. R.
     68-69:056-008

Fuchs,  M.
     68-69:03F-006
     68-69:020-003
Fungaroli, A.
     68-69 :02F-019
     68-69 .-02G-042
     68-69 :02F-020
Fryrear, D.  W.
     68-69:02D-006
     68-69 :02J-008

Galegar, William C.
     68-69:076-018

Gangopadhyaya, M.
     68-69 :03F-011

Gardiner, H.
     68-69 :02K-018

Gardner, H.  R.
     68-69 :02D-008
     68-69.-02G-010

Gardner, W.  R.
     68-69:020-009
     68-69:02G-009
     68-69:02G-OlO

George, M. G.
     68-69 :05F-004

Glandon, L.  R., Jr.
     68-69 :05B-018

Glazkov, N.  P.
     68-69:076-020

Goldberg, M. C.
     68-69:02K-010

Goodrich, P. R.
     68-69:05B-004

Grable, A. R.
     68-69 :02K-020

Graham, K.
     68-69:02G-011

Federal Water  Quali",y
  Administration
     68-69:056-027

-------
 Grant, W. J.
       68-69:02E-005
 Hemens,  J.
      68-69 :05D-007
 Jamieson, D. G.
      68-69:02E-009
 Grass, Luther B.
       68-69:02F-015
       68-69:050-003
       68-69:02F-016
       68-69:056-010
 Hendrickson, R.  A.
      68-69 :02G-054

 Herbert,  D.  J.
      68-69:02P-037
Jarman, G. D.
      68-69:02G-048

Jenab, S. A.
      68-69:02F-040
 Gray, T. N.
       68-69:02G-007

 Grimes, D. W.
       68-69:021-012
 Hesse,  V.  L.
      68-69 :03F-028

 Hill,  R.  D.
      68-69 :05D-006
Javandel,  Iraj
      68-69.-02E-001

Jenkins, C. T.
      68-69:02F-045
 Grogan, C. 0.
       68-69:02I-009
 Hinesly,  Thomas  B.
      68-69 :05E-003
Jennings, A. Ray
     68-69:02F-023
 Haas, H. J.
       68-69:03F-025
 Hirsch,  L.
      68-69:05D-001
Jensen, M. E.
     68-69:03F-012
 Hagan, Robert M.
       68-69:020-017
       68-69:02D-025

 Haghiri,  F.
       68-69:056-017

 Haise, Howard R.
       68-69:03F-002

 Hajek, 3.  F.
       68-59:-5D-004

 Hall,  Warren  A.
       68-69:03F-013

 Hamdy, M.  Y.
       63-69:04A-011

 Hanks, R.  J.
       63-69:02D-008
       68-69.-02G-020

 Hargreaves, George  H.
       68-69:03F-018

 Harrold, Lloyd L.
       68-69:02J-010
       68-69:058-020
       68-69:058-021

 Hart,  G. E.
       68-69:020-019

 Hart,  William E.
       68-69:03F-019
       68-69:03F-022
       68-69:04A-003

 Harter R. D.
       68-69:C2K-015
       68-69:02J-002

 Hartman, Monroe A.
       68-69:02E-007

 Hauser, Victor L.
       68-69:03C-002
       68-69:058-026

Heeimann,  D. F.
       63-69:02E-008
 Herkelrath,  W.  N.
      68-69:07B-014

 Hoffman,  G.  J.
      68-69:07B-014
      68-69:07B-023

 Hogg,  H.  C.
      68-69 :06B-003

 Holt,  R.  F.
      68-69 .-03F-015

 Holtan, H. N.
      68-69:040-001

 Hornberger,  G.  M.
      68-69 :02F-019

 Huang, B. K.
      68-69 -.020-029

 Huggins,  L.  E.
      68-69 :02G-013

 Humpherys, Alan S.
      68-69:04A-006

 Hungate,  F.  P.
      68-69:020-014

 Hurley, Patrick A.
      68-69:05B-002

 Hutchinson,  G.  L.
      68-69:02F-050
      68-69 :05C-001

 Hylton, L. 0.
      68-69 -.021-021

 Ingvalson, R. D.
      68-69:02G-038

 Jacobs , II. S.
      58-69:020-022

 Jacobson,  P.
     68-69:02J-004

Johr.son, William
     68-69:02K-007
Jeppson, Roland W.
     68-69:02G-043

Jobes, H. D.
     68-69:050-003

Johnson, C. B.
     68-69:02E-003

Jones, E. B.
     68-69:07A-001

Jones, Benjamin A., Jr.
     68-69.-06E-004

Jones, J. N., Jr.
     68-69:03F-021

Jones, Ordie R.
     68-69:02F-012

Jopling, William F.
     68-69:050-005

Jordan, C. F.
     68-69:078-006

Jorgensen, Donald G.
     68-69:02F-042

Joyce, Robert T.
     68-69:076-012

Kalinin, Ya. D.
     68-69:03C-005

Kandil, M. F.
     68-69:02J-005
     68-69:02J-006

Karadi, Gabor
     68-69:02F-021

Kardos, L. T.
     68-69:021-008

Karolus, Walter J.
     68-69:02F-032
                                      176

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 Kashef, Abdel-Aziz  I.
       68-69:02F-017
Krueger, D. B.
     68-69:05A-001
Lo, K. M.
     68-69:02F-010
 Keeley, Jack W.
       68-69:05B-023
       68-69:058-026

 Kemper, W. D.
       68-69:02G-031
       68-69:02G-035
       68-69:02G-008

 Kevi,  L.
       68-69:02F-038

 Khasawneh, F. E.
       68-69:078-002

 Kidder, E. H.
       68-69:02G-025

 Kincaid, D. C.
       68-69:02E-008

 King,  P. H.
       68-69:04A-005
       68-69:05A-007

 Kirkham, Don
       68-69:02F-024

 Kleshchenko, A. D.
       68-69:02G-018

 Klock, G. 0.
       68-69:02G-005
       68-69:02G-037

 Klotz, Dietmar
       68-69:02F-034

 Klute, A.
       68-69:02G-006
       68-69:02G-020

 Knisel, Walter G., Jr.
       68-69:02E-007

 Koch, Arnd.
       68-69:02F-034

 Kowsar, Ahang
       68-69:02G-048

 Kramer, L.  A.
       68-69:02J-016

Kreis, Douglas
       68-69:02K-007

Krishnamurthy, K.
       68-69:02G-056

Kriz, G. J.
       68-69:05C-003

Krizek, Raymond J.
      68-69.-02F-021
Krupp, H. K.
     68-69 .-02G-055

Kruse, E. G.
     68-69:02E-008
     68-69:03F-002

Kunze, R. J.
     68-69:02G-011

Kuz'min, P.  P.
     68-69:020-012

Laag, A. E.
     68-69:02G-066

Laflen, J. M.
     68-69:02J-003

Laliberte, G. E.
     68-69:02F-009
     68-69:02F-022

Lang, A. R.  G.
     68-69:02G-016

Larson, M. B.
     68-69:02G-050

Larson, W. E.
     68-69:02G-059
     68-69:02G-063
     68-69:C2G-070

LaRue, M. E.
     68-69:02G-044

Laughlin, W. M.
     68-69:02K-017

Law, J. P.,  Jr.
     68-69:020-069
     68-69.-05C-005

Lee, G. F.
     68-69:05G-009

Lee, Richard
     68-69:07A-001

Letey, J.
     68-69:02G-031
     68-69:02G-035
     68-69:021-023

Li, W. H.
     68-69:02F-001

Lillard, J.  H.
     68-69 .-03F-021

Linacre, E.  T.
     68-69:03F-030

Lindstrom, F. T.
     68-69:02K-018

Lehman, Oliver R.
     68-69:030-002
Longenecker, D. E.
     68-69:021-006
     68-69:03F-017

Lotspeich, Frederick B.
     68-69:03C-002

Loudon, T. L.
     68-69:020-023

Love, S. K.
     68-69:05G-012

Luebs, R. E.
     68-69:02G-066

Lathin, James N.
     68-69:020-039
     68-69 :07C-001

Lytz, J. F.
     68-69:05A-006

Lyerly, P. J.
     68-69:021-006
     68-69.-03F-017

Lyford, Forest P.
     68-69:02G-003

Macumber, P.  G.
     68-69:02J-013

Mann, H. 0.
     68-69:050-004

Mann, John F., Jr.
     68-69 .-02F-039

Mannering, J. V.
     68-69:02E-003
     68-69:02J-012

Marius, John B.
     68-69:078-012

Martin, Glen L.
     68-69:02J-011

Martin, Paul E.
     68-69:020-025

Masloc, Boris
     68-69 :02G-039

Mason,  M. H.
     68-69:050-007

Maxey,  George B.
     68-69:020-002

Maxor,  E.
     68-69:02F-044

McCants, C. B.
     68-69:02K-004
                                      177

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 McCarty, P. L.
        68-69:05A-007
        68-69:050-009
        68-69:05F-002

 McCulloch, J. S. G.
        68-69:076-022

 MeHenry, J. Roger
        68-69:02J-009

 McLaren, Douglas A.
        63-69:02K-009

 McMahon, J. W.
        68-69 :05A-008

 McK.illion,  Leslie G.
        63-69:05B-023
        68-69:05B-026

 McMullin, R. J.
        63-69.-03F-007

 McQueen, Irel S.
        68-69:078-011

 Meek, B. D.
       68-69:02F-016
       68-69:05G-003
       68-69:05B-010

 MacKenzie,  A.  J.
       68-69:05B-010

 Mein, R. G.
       68-69:04A-009

 Meyer,  L..D.
       68-69:02J-016

 Mickelson,  R.  H.
       68-69:02G-032

 Miller, Howard
       68-69:03F-016

 Miller, R.  J.
       68-69:07B-004

 Miller, Reuben F.
       68-69:076-011

 Minshall, Neal
       68-69:056-003

 Mofaasheri,  Fereidoun
       68-69:02F-043

 Moe,  P.  G.
       68-69:02E-003

 Mokady,  R.  S.
       68-69:02F-048

 Moldenhauer, W.  C.
      68-69.-02G-008

Molz, F. J.
      68-69:02F-020
      68-69:020-042
 Monke,  E.  J.
      68-69 :02G-013
      68-69 :05B-004

 Monteith,  J.
      68-69:06A-001

 Moody,  J.  E.
      68-69 :03F-021

 Morgan,  P. E.
      68-69 :06B-004

 Morton,  F. I.
      68-69:02D-001

 Mote, C. R.
      68-69:036-001

 Moulder, E. A.
      68-69 :02F-045

 Mueller, K. E.
      68-69 :02I-004

 Mukherjee,  R. K.
      68-69:03F-010

 Musick,  J.  T.
      68-69:02G-026

 Muta, Kazuki
      68-69 :02G-040

 Mutchler,  Calvin K.
      68-69:02J-007

 Myers, P.  M.
      68-69:06A-001

 Myers, V.  I.
      68-69.-02F-033

 Myhre, D.  L.
      68-69:021-009

Myhrman, Matts A.
      68-69:02G-041

 Nakayama,  F. S.
      68-69:02K-011

 Namken, L. N.
      68-69:02F-008
      68-69:021-018

 Narale, R.  P.
      68-69:03F-010

 Nash, R. G.
      68-69:02K-003
      68-69:05A-009

Nelson, W. W.
      68-69:02G-015

 Nemeryuk,  G. Ye.
      68-69:020-028

Neuman, S. P.
      68-69:02F-049
Nichols, M. Starr
     68-69:056-003

Nielsen, D. R.
     68-69:020-007
     68-69:02G-044
     68-69:02G-060

Nightingale, H^rry I.
     68-69:05G-010

Nix, H. A.
     68-69:02D-015
     68-69:020-026

Nowland, J. L.
     68-69:02J-005

Nwa, E. U.
     68-69:02A-001

Nye, P. H.
     68-69:02K-013

Obbink, J. Groot
     68-69:02F-002

Oelke, E. A.
     68-69:021-004

Oertli, J. J.
     68-69:021-013

Oertli, J. J.
     68-69:021-014
     68-69:021-015

Ogata, G.
     68-69:02F-025
     68-69:030-003

Olsen, Harold W.
     68-69:076-016

Ortoiano, Leonard
     68-69:03A-001

Oster, J. D.
     68-69.-02G-038

Overman, A. R.
     68-69:078-004

Overrein, L. N.
     68-69:02K-016

Owen, L. W.
     68-69:02F-047

Page, Leo M.
     68-69:02F-014

Pair, Claude H.
     68-69:02A-002

Pankow, J.
     68-69:076-009

Parker, D. S.
     68-69:066-002
                                       178

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 Passioura,  J.  B.
      68-69:020-014

 Patrick,  W.  H., Jr.
      68-69.-02K-002

 Patterson,  P.  M.
      68-69:03F-005

 Patterson,  R.  M.
      68-69:03F-008

 Pavelis,  G.  A.
      68-69:063-005

 Payne,  D.
      68-69.-02G-061

 Peck, A.  J.
      68-69:076-013

 Peterson, Dean F.
      68-69:02F-040

 Peterson, L. A.
      68-69:050-007

 Peverly,  J.  H.
      68-69:073-004

 Pierce, W. H.
      68-69:053-018

 Pionke, H. B.
      68-69:05A-005

 Pira, E.  S.
      68-69:02G-040

 Pomytkin, B. A.
      68-69:020-012

 Porter, L. K.
      68-69:02K-020

 Postlewaite, J. E.
      68-69:02G-050

 Poulovassilis, A.
      68-69:02G-057

 Powell, R. D.
      68-69:021-008

 Powers, W. L.
      68-69:020-022

 Pressman, A. E.
      68-69:05A-003

 Preul, H. C.
      68-69:02K-006

Prihar, S. S.
      68-69:020-011
      68-69:07B-007

Prokopovich, N. P.
      68-69:02F-037

Qashu, Hasan K.
     68-69:02G-003
Raats, P. A. C.
      68-69:02G-006
      68-69:02G-046

Rabbidge, R. M.
      68-69:076-013

Racho, V. V.
      68-69:021-010

Rambie, G. S.
      68-69:05A-003

Randall, C. W.
      68-69:04A-005

Rao,  S. M.
      68-6"9:02G-056

Rapo, E.
      68-69:02F-009

Rasmussen, P. E.
      68-69:05B-013

Ravina, I.
      68-69:02F-048

Rawlins, S. L.
      68-69:020-009
      68-69:026-038

Read, L. W.
      68-69 .-02G-069

Reeve, R. C.
      68-69:02F-003

Reiniger, P.
      68-69 :03C-004

Remson, Irwin
      68-69 :02F-019
      68-69:02F-020
      68-69 :02G-042

Rhoades, J. D.
      68-69:02G-024
      68-69:05A-001

Rice, R. C.
      68-69:04A-004
      68-69:078-019

Richards, Sterling J.
      68-69:02G-027

Richardson, Bland Z.
      68-69:078-015

Richardson, C. W.
      68-69:02J-008

Richardson, W. F.
      68-69:021-014

Rickard,  D. S.
      68-69.-02G-004

Rijtema,  P. E.
      68-69 :07B-010
Ritchie, J. T.
     68-69:020-006

Robbins, J. W. D.
     68-69 :05C-003

Robinson, Frank
     68-69:02G-039

Robeck,  G. G.
     68-69:050-006

Rose, C. W.
     68-69:020-010
     68-69:07B-017

Rose, D. A.
     68-69 :02G-051

Rosenberry, P. E.
     68-69:068-005

Rosenthal, E.
     68-69 :02F-044

Rowell,  D. L.
     68-69:02G-061

Runkles, J. R.
     68-69:021-018

Ryhiner, A. H.
     68-69 :07B-009

Sabey, B. R.
     68-69:058-009

St. Amant, P.  P.
     68-69:050-002
     68-69:050-009
     68-69:05F-002

Sakkas,  J. G.
     68-69:03F-022

Sandhy,  B. S.
     68-69:078-007

Sandoval, F. M.
     68-69:020-032

Sanford, J. O.
     68-69:021-009

Sannikov, G. P.
     68-69:02F-006

Savel'yeva, R. V.
     68-69:020-049

Scalf, Marion R.
     68-69:058-023
     68-69:05B-026

Scarsfarook, C. E.
     68-69:021-005

Schachterle, D. M.
     68-69:04A-012
                                       179

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 Schneider, Arland D.
      68-69:02F-012
      68-69:02G-026

 Schneider, R. F.
      68-69:07B-008

 Schroeder, Melvin C.
      68-69:02F-023

 Schroepfer,  G. J.
      68-69:02K-OG6

 Schultz,  J.  D.
      68-69:02D-019

 Schwab,  G. D.
      63-69:020-012

 Schwab,  G. O.
      68-69:04A-011
      68-69:05B-015

 Scott, Verne H.
      68-69:02F-04I

 Seginer,  I.
      68-69:02D-C18
      68-69:03F-004

 Sendiein,  L.  V.  A.
      68-69:076-021

 Seth, A.  K.
      68-69:05F-004

 Sewell, John I.
      63-69:02K-008
      68-69:038-001
 Skidmore,  E.  L.
      68-69:020-022

 Skodje,  M.  T.
      68-69:02F-028

 Sloneker,  L.  L.
      68-69:02G-015

 Smerdon, E. T.
      68-69:03F-003

 Sraika, D.  E.
      68-69:03F-024

 Soileau, J. M.
      68-69.-07B-002

 Sopper,  William E.
      68-69:02F-011

 Sosewitz,  Ben
      68-69:05E-003

 Spencer, James R.
      68-69:02G-021

 Splinter,  W. E.
      68-69:020-029
      68-69:078-023

 Stanhill, G.
      68-69:03F-006

 Stegman, E. C.
      68-69:02G-025

 Stephenson, D. A.
      68-69:05E-004
 Subramanyam,  T. K.
      68-69:03F-010

 Sv;ord, B. R.
      68-69:050-010
      68-69:05E-001

 Szabo, Barna  A.
      63-69 :02F-018

 Szeicz, G.
      68-69:021-020

 Tajchman, S.
      68-69:021-020

 Tamblyn, T. A.
      68-69:05E-001

 Tanner, C. B.
      68-69:02D-OC3

 Taylor, Edward F.
      68-69:06E-002

 Taylor, G. C.
      68-69:05A-004

 Taylor, G. S.
      68-69:053-015

 Taylor, George S .
      68-69:070-001

 Taylor, Robert L.
      68-69:04A-008

 Thames, John  L.
      68-69:02G-062
Shahbazi, M.
     68-69:02F-043
Stevenson, C. K.
     68-69:02K-005
Thaxton, E. L., Jr.
     68-69:03F-017
Shalhevet, J.
     68-69:021-019
     68-69:03C-004
Stewart, B. A.
     68-69:02F-050
     68-69 :05C-001
Thomas, Grant W.
     68-69:02G-017
     68-69 :02G-019
Shannon, John K.
     68-69:020-021

Sharrna, V. P.
     68-69:05F-C04

Shimshi, D.
     63-69:030-004

Sheets, T. J.
     68-69.-05A-006

Shen, C. Y.
     68-69:02G-050

Shields, Ronald R.
     68-69:02F-011

Shin, Chau
     68-69:02D-013

Skaggs, R. W.
     68-69:02G-013
Stewart, E. H.
     68-69:02D-027

Stewart, J. Ian
     68-69:020-017

Stone, L. R.
     68-69:02G-044

Stolzy, L. K.
     68-69:021-023

Stone, J. F.
     68-69:021-003

Storch, William V.
     68-69:04A-008

Strachan, J. K.
     68-69:02F-035

Strelkoff, Theodor
     68-69:03F-019
Thomas, R. E.
     68-69:05E-002

Thorup, R. M.
     68-69:03F-026

Thurtell, G. W.
     68-69:020-003
     68-69:02G-009

Till, M. R.
     68-69:03F-030

Timmons, D. R.
     68-69:03F-015

Tinker, P. B.
     68-69.-02G-034

Tinsley, J.
     68-69:02J-005
     68-69:02J-006
                                       180

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Todd,  D.  K.
      68-69:02F-043

Tovey,  Rhys
      68-69-.02G-028
      68-69:021-016

Trent,  D.  S.
      68-69 :02G-050

Trock,  Warren L.
      68-69:06E-003

Tucker, B. B.
      68-69:021-003

Tucker, J. M.
      68-69:02F-025
      68-69:030-003

Turner, A. K.
      68-69.-02F-035
      68-69 -.04A-009

Twocock,  J. G.
      68-69:02A-001

Uehara, G.
      68-69:02G-011

Underbill, H. W.
      68-69:08A-001

Underwood, C.
      68-69:05G-004

Vaidyanathan, L. B.
      68-69:02K-013

Van Lopik, J. R.
      68-69:05A-003

Viets, F. G., Jr.
      68-69:02F-050
      68-69:050-001
Ward, P. R. B.
     68-69:02F-029

Warkentin, B. P.
     68-69:02K-019

Warner, D. L.
     68-69:058-024

Warren, P. S.
     68-69:04A-005

Warrick, A. W.
     68-69:020-007
     68-69 .-02F-024

Watson, Keith K.
     68-69:02G-029

Watts, D. G.
     68-69:02G-005

Webber, L. R.
     68-69:058-022

Weeks, Edwin P.
     68-69:02F-031

Weeks, Lowell O.
     68-69:02G-021

Wei, I. W.
     68-69:05F-003

Weibel, S. R.
     68-69:058-005

Weidner, R. B.
     68-69:056-005

Weijenberg, J.
     68-69:078-003

Wershaw, R. L.
     68-69:02K-010
Willardson, L, S.
     68-69:02F-003
     68-69:02F-016
     68-69:05G-003

Williams, M. A. J.
     68-69:058-007

Williams, Roy E.
     68-69:04A-010

Williamson, R. E.
     68-69:02G-007

Willis, G. H.
     68-69:02J-003

Willis, W. 0.
     68-69:02G-032
     68-69:03F-025

Winger, R. J., Jr.
     68-69:05G-006

Wischmeier, W. H.
     68-69 :02J-012

Witherspoon, Paul A
     68-69 :02E-001
     68-69 :02F-049

Wittmuss, H. D.
     68-69:021-017

Witzel, S. A.
     68-69:056-003

Woerner, Jack
     68-69:02G-039

Wolf, M. A.
     68-69:020-014

Wolff, Roger G.
     68-69:076-016
Vol'ftsun, I. V.
     68-69:02F-013
Whisler, Frank D.
     68-69:02G-029
Woolson, E. A.
     68-69:05A-009
Vemuri, Venkateswararao
     68-69:02F-032
Whitney, L. F.
     68-69-.02F-010
Wurzel, P.
     68-69:02F-029
Venkatoraman, S.
     68-69:03F-011
Wicks, G. A.
     68-69:03F-024
Yamada, H.
     68-69:021-012
van't Woudt, B. D.
     68-69:03F-027
Wiebenga, W. A.
     68-69:02F-038
Yao, A. Y. M.
     68-69:020-004
Wadleigh, Cecil H.
     68-69:058-006

Waggott, A.
     68-69:058-011

Waldron, A. C.
     68-69:058-015

Walsh, R.
     68-69:056-005

Utah State University
  Foundation
     68-69:058-028
Wiegand, C. L.
     68-69:02F-008

Wiersma, J. L.
     68-69:02E-004

Wiley, C. R.
     68-69:02G-007

Wilke, 0. C.
     68-69:03F-003
Yaron, Bruno
     68-69:020-017
     68-69:02G-019

Yaron, Dan
     68-69:066-001

Yen, G. T.
     68-69.-02F-001

Yeh, H. H.
     68-69:04A-005
                                       181

-------
Young, D. F.
     68-69:068-006

Young, Robert A.
     68-69:02J-007

Young, L. L.
     68-69:056-014

Youngs, E. G.

     68-69:020-065
     68-69:04A-002

Yu, P. T.
     68-69:021-023

Zaslavsky, D.
     68-69:02F-048

Z iemann,  H.
     68-69:050-002
                                       182

-------
                                    SECTION  XXXII

                                    SUBJECT  INDEX
Abatement
      68-69:050-008

Absorption
      68-69:02G-016
      68-69 .-02K-003
      68-69 :02I-019

Acetic acid
      68-69:05F-002

Acetone
      68-69 .-05F-002

Acidic soils
      68-69:02G-067

Acidity
      68-69:02K-011

Acids
      68-69.-OSA-008

Activated carbon
      68-69:04A-005

Adoption of practices
      68-69:06B-005

Adsorption
      68-69:02F-023
      68-69:02G-017
      68-69:02G-024
      68-69:02G-061
      68-69:02K-006
      68-69:03C-004
      68-69 :03C-003
      68-69:04A-005
      68-69:056-023
      68-69 .-05E-004

Advection
      68-69 :02I-020

Aeration
      68-69:02F-016
     68-69:02G-007
      68-69:02G-025
     68-69:021-023
     68-69:050-009

Aesthetics
     68-69:030-001

Agricultural chemicals
     68-69:030-001
     68-69:02J-003
     68-69:058-004
     68-69:053-020
     68-69.-05C-005

Agricultural engineering
     68-69:02A-001
     68-69:02E-002
     68-69:05C-003
     68-69:068-006
Agricultural watersheds
     68-69:02J-010

Agriculture
     68-69:020-022
     68-69.-02F-050
     68-69:02G-013
     68-69:02J-003
     68-69:02J-017
     68-69:03F-008
     68-69:03F-025
     68-69:05A-004
     68-69:058-022
     68-69:05C-001
     68-69:05C-003
     68-69:05E-003
     68-69:06E-004

Agronomy
     68-69:020-022
     68-69:03F-023
     68-69:05A-007
     68-69:058-008

Air circulation
     68-69:020-023
     68-69:02G-050

Air environment
     68-69:021-013

Air temperature
     68-69:03F-006

Alaska
     68-69:02K-017

Albedo
     68-69:020-018
     68-69--03F-006

Alcohols
     68-69:05C-004

Aldrin
     68-69:05A-009

Alfalfa
     68-69:020-017
     68-69 :02D-023
     68-69:02F-025
     68-69 :02F-05Q
     68-69:02G-005
     68-69:021-016
     68-69 :02I-019
     68-69:02K-003
     68-69:03C-003
     68-69 :05C-001
Algae
     68-69 :02J-002
     68-69:04A-005
     68-69:050-002
     68-69 :05D-007
Alkaline earth metals
     68-69 :05A-001

Alkaline water
     68-69:02G-017

Alkaline soils
     68-69:02G-061

Alkalinity
     68-69:02G-069

Alluvium
     68-69:02F-012
     68-69.-02J-013

Altitude
     68-69:020-023

Aluminum
     68-69:02K-015

Alpha rays
     68-69:02J-009

Ammonia
     68-69:05G-009

Ammonium'
     68-69 :02K-009

Ammonium compound
     68-69:021-001

Ammonium compounds
     68-69:02E-003
     68-69:02G-069
     68-69 :02K-005
     68-69 :02K-014

Anaerobic bacteria
     68-69:02K-012
     68-69:050-009

Anaerobic conditions
     68-69:02F-046
     68-69 :02K-002
     68-69 :05D-009
     68-69:058-010
     68-69 :05G-003

Analog computers
     68-69:020-013
     68-69 :02F-032
     68-69 :04A-011

Analog models
     68-69 .-02F-033
     68-69:02F-045
     68-69:04A-009

Analysis
     68-69:02E-001
     68-69:02G-013
     68-69:02J-003
                                      183

-------
 Analytical technique
      68-69:03F-013

 Analytical techniques
      68-69:020-024
      68-69:02G-029
      68-69:05A-005
      68-69:07A-001
      68-69:02F-043
 Anemometers
      68-69:03F-006

 Animal waste
      68-69:05B-020
      68-69:05B-006

 Anisotrophy
      68-69.-02E-001
      68-69:02F-004
      68-69:02F-024
      68-69:02F-021
      68-69:02G-043

 Annelids
      68-69.-02K-007

 Antecedent precipitation
      68-69:020-016
      68-69:02F-026

 Application equipment
      68-69-.03F-027

 Application methods
      68-69:02E-008
      68-69:02F-010

 Approximation  method
      68-69:02F-020
      68-69:020-043
      68-69:02K-013

 Aquatic  habitats
      68-69:050-002

 Aquatic  plants
      68-69:04A-012
      68-69:05B-022

 Aquatic  weed control
      68-69:04A-012

 Aqueous  solutions
      68-69:02G-046
      68-69:02G-052
      68-69:02K-011

Aquicludes
      68-69:02F-017
      68-69:02F-049
      68-69:07B-016

Aquifer
      68-69:02F-007
      68-69:02K-001
      68-69:076-021

Aquifer characteristics
      68-69:02F-044
      68-69:02F-041
      68-69:078-021
 Aquifers
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
:02E-001
:02F-002
:02F-011
:02F-012
:02F-014
:02F-017
:02F-031
:02F-032
:02F-033
:02F-039
:02F-042
:02F-043
:02F-045
.•02F-049
:03C-002
: 04A-002
:04A-010
:05B-026
:07B-016
 Aird  lands
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
:02D-002
:02D-023
:02E-002
.-02F-009
:02F-025
:02G-003
:02G-024
:02K-014
.-05A-001
:02G-021
:02G-051
:02I-011
:02I-013
:03C-001
:03C-004
.-08A-001
Available moisture
      68-69:02G-004

Available water
      68-69:021-002

Backfill
      68-69:02F-046

Bacteria
      68-69:058-005
      68-69:050-002

Bank  storage
      68-69:02F-026

Barley
      68-69 :02I-013
      68-69:021-023
      68-69:03C-001

Base  flow
      68-69:02F-026
      68-69:02F-029
      68-69:05B-003

Basin Commission
      68-69:06E-002
Beans
     68-69:05G-007
Arizona
     68-69:030-001

Artesian wells
     68-69:02F-042

Artificial precipitation
     68-69 :02G-015

Artificial recharge
     68-69:04A-010

Assessments
     68-69:068-004

Atmometers
     68-69:020-021
     68-69:03F-030

Atmosphere
     68-69.-02D-028
     68-69:02G-051

Automatic control
     68-69:03F-001
     68-69.-03F-002
     68-69 :04A-006

Automation
     68-69:03F-001
     68-69.-04A-006
     68-69:05A-002
Beds
     68-69:02F-031

Benefits
     68-69:05G-011
     68-69:021-017

Bench leveling
     68-69:021-017

Benthic
     68-69:02K-007

Bentonite
     68-69:02G-019

Bermudagrass
     68-69:020-027

Beta rays
     68-69:02J-009

Bibliographies
     68-69:020-022
     68-69:02F-015
     68-69.-02F-034
     68-69:02F-039
     68-69:02G-013
     68-69:02J-009
     68-69:04A-010
     68-69:058-004
     68-69:050-003

Bicarbonates
     68-69:02K-011

Biochemical oxygen demand
     68-69:058-005
                                       184

-------
Biodegradation
     68-69:02F-016
     68-69:02K-012
     68-69:050-004

Biological communities
     68-69:050-002

Biology
     68-69:050-002

Bodies of water
     68-69:05A-008

Border irrigation
     68-69 .-02G-069

Borehole geophysics
     68-69 :07B-021

Boreholes
     68-69:076-015
     68-69:07B-021

Bloodworms
     68-69:02K-007

Boron
     68-69:02K-017
     68-69:05B-011

Boundaries (Surfaces)
     68-69 :02F-032

Boundary values
     68-69:020-020

Brines
     68-69:076-018

Browse utilization
     68-69:021-021

Bulk density
     68-69:02J-012

Caddisflies
     68-69:02K-007

Calcium
     68-69:02F-007
     68-69 .-02G-069
     68-69:021-001
     68-69:02K-001
     68-69:02K-017
     68-69 .-03C-003
     68-69:05A-001
     68-69 :07B-006

Calcium carbonate
     68-69 .-03C-003
     68-69:08A-001

Calcium chloride
     68-69:02F-048

Calcium sulfate
     68-69 :02K-019

Calibration
     68-69:078-022
     68-69:078-023
Calibrations
     68-69:02G-028
     68-69:076-009
     68-69:076-010
     68-69:078-011

California
     68-69:02F-025
     68-69.-02F-032
     68-69:02F-036
     68-69:02F-037
     68-69:020-021
     68-69:05D-005
     §8-6.9:0.5G-Q1Q
     68-69:021-011

Canal seepage
     68-69:020-056
     68-69.-02F-037
     68-69:04A-004
     68-69:08A-001

Canneries
     68-69:050-006

Capillary action
     68-69:020-009
     68-69:020-037

Capillary conductivity
     68-69:020-033
     68-69:020-045

Carbonates
     68-69:02K-011

Cation exchange
     68-69:020-017
     68-69:020-024
     68-69:03C-003

Cations
     68-69:020-034

Cattails
     68-69:04A-012

Channels
     68-69:020-043
     68-69:03F-003

Check dams
     68-69 .-04A-006

Check structures
     68-69:02J-004
     68-69:04A-006

Chemcontrol
     68-69:020-025

Chemical analysis
     68-69:02F-044
     68-69:05E-001

Chemical oxygen demand
     68-69:05D-006

Chemical potential
     68-69:02K-011

Chemical precipitation
     68-69:02F-015
     68-69:03C-003
Chemical properties
     68-69 .-05B-007

Chemicals
     68-69:02J-003
     68-69 :02K-018

Chemistry of precipita-
  tion
     68-69 :02D-028

Chlorides
     68-69:020-028
     68-69:05G-002

Chlorination
     68-69:05F-004

Chromatography
     68-69 :02F-048
     68-69:020-017
     68-69:02J-003
Circulation
     68-69:02F-027

Circulation (Plants)
     68-69:021-014

Citrus fruits
     68-69:04A-008

Classification
     68-69 :05C-002

Clay
     68-69 .-07B-004

Clay minerals
     68-69:02G-017

Clays
     68-69:02J-003
     68-69 :02J-012
     68-69:02K-005
     68-69 :02K-018
     68-69 :02K-019
     68-69:04A-005
     68-69:050-004
Climate
     68-69:03F-012

Climates
     68-69:020-002
     68-69:04A-007

Climatic data
     68-69:020-021
     68-69:020-024
     68-69:020-032
     68-69:03F-006
     68-69:020-026
     68-69 :03F-018
Climatology
     68-69:020-020
     68-69:020-015
     68-69 :07A-001
Cloud cover
     68-69:020-023

Coals
     68-69:04A-005

Cobalt
     68-69:02K-017
                                      185

-------
 Colorado
      68-69:050-004

 Column chromatography
      68-69:05A-005

 Communication
      68-69:030-001

 Computer
      68-69-.02G-011

 Computer models
      68-69:020-013
      68-69:02F-032
      68-69:02F-036
      68-69:02F-045

 Computer Drogramming
      68-69:02G-020

 Computer programs
      68-69:02F-020

 Computer simulation
      68-69:05E-005

 Computers
      68-69:03F-007
      68-69:03F-012
      68-69:03F-028

 Condensation
      68-69:02G-050

 Confined water
      68-69.-02G-032

 Conjunctive  use
      68-69:02F-036

 Conservation
      68-69:03F-014
      68-69:04A-008
      68-69:06B-005

 Construction
      68-69:06A-001
 Convection
      68-69:02D-013
      68-69:02C—046
      68-69:02G-049
      68-69:02G-060

 Cooling
      68-69:020-014

 Copper
      68-69:02K-017
 Cores
      68-69:07B-008

 Corn
      68-69 .-021-009
      68-69:021-023
      68-69:02J-017
      68-69:02K-005
      68-69:03F-021
      68-69:03F-025
      68-69:05G-007

 Corn  (Field)
      68-69:02D-020

 Corn  Belt
      68-69:02D-020
      68-69:02E-004

 Correlation analysis
      6S-69:C2G-013

 Corrosion
      68-69:02F-005
Cost
      68-69 :03F-Oi;
Cost-benefit analysis
     68-69-.C3A-001
     68-69:03F-013
     68-69 :05G-011
     68-69:06B-004
 Crop  production (Cont.)
      68-69:02D-017
      68-69:02D-020
      68-69:020-026
      68-69 :02E-004
      68-69.-02G-026
      68-69 :02I-003
      68-69 :02I-008
      68-69:021-009
      68-69:02I-010
      68-69:02I-011
      68-69 :02I-012
      68-69:02I-017
      68-69:02J-008
      68-69:03C-004
      68-69:04A-007
Crop  response
      68-69:020-023
      68-69:02I-007
      68-69:02I-009
      68-69:02I-011
      68-69:021-012
      68-69 :02I-017
      68-69:02I-019
      68-69 :03C-004
      68-69:03F-006
      68-69:03F-020
      68-69:03F-027
      63-69:03F-030
      68-69:04A-007
      68-69:05B-013
Crop  yield
      68-69:03F-017
                                Crops
     68-69:02D-012
     68-69:02D-022
     68-69 :02E-006
     68-69:021-020
     68-69:02J-012
     68-69 :02K-003
     68-69 :04A-010
     68-69 :05E-003
     68-69 -.05G-007
Consumptive use
     68-69:02E-008
     68-69 :02I-016
     68-69:02I-002
     68-69:03F-018
     68-69:04A-007
     68-69:05B-028
     68-69:07A-001
Contour farming
     68-69 :02E-004
     68-69:02J-004

Contours
     68-69 :02F-032

Control structures
     63-69 --04A-006

Control systems
     68-69 -.03F-001
     68-69:04A-006
     68-69:05G-002
Costs
     68-69-.02F-010
     68-69:06B-004

Cotton
     68-69:02D-015
     68-69:02F-OOS
     68-69:02G-016
     68-69:02I-001
     68-69:02I-005
     68-63:02I-006
     68-69:02I-001
     63-69:021-012
     68-69:02I-018
     68-69:03F-006
     68-69:03F-017

Cover crops
     eS-6'3 :02J-014

Crop production
     68-69:0213-014
     <58-63:02D-015
Cultivated lands
     68-69.-02J-008
     68-69:05A-009
Cultivation
     68-69:02E-006
     68-69:02G-Ol5
     68-69:02G-059
     68-69 :03F-021
     68-69 .-03F-023
     68-69 :05C-004
Cytological studies
     68-69 :02I-013
     68-69 :02I-015

Dairy Industry
     63-69.-05B-008

Damages
     68-69 :02F-037

-------
 Dams
      68-69:02F-034

 Darcy's  Law
      68-69:02F-018
      68-69:02F-019
      68-69:02F-041
      68-69:02G-006
      68-69:02G-033
      68-69:026-044
      68-69:020-045
      68-69:020-064
      68-69--02K-008
      68-69 :02F-030

 Data  collections
      68-69:020-017
      68-69:020-021
      68-69:020-024
      68-69:020-026
      68-69:02E-008
      68-69 :03F-012
      68-69:05A-002
      68-69:05G-012
      68-69 :07A-001
Data processing
     68-69:02F-032
     68-69:03F-007
     68-69 .-03F-012
DDT
     68-69:02E-005
     68-69:02K-003
     68-69:02K-010
     68-69:05B-023
     18-69:05B-026
     68-69 .-05A-006

Decision making
     68-69:030-001
     68-69:05A-004
Deep percolation
     68-69 :02G-009
     68-69:053-002
Defoliants
     68-69:05A-006

Delaware River
     68-69 :06E-002

Demand
     68-69 :05G-011
     68-69:068-002

Demonstration watersheds
     68-69:02F-026
     68-69:02j-008
     68-69:020-016

Denitrification
     68-69:02F-016
     68-69:058-010
     68-69:050-002
     68-69:050-009
     68-69:05E-001
Denitrification  (Cont.)
     68-69:05F-002
     68-69:05G-003
     68-69:05G-009
     68-69:058-018

Density
     68-69:02F-027
     68-69:020-038
     68-69:078-009
     68-69:078-010
Deposition
     68-69:02F-015

Desalination
     68-69:050-010
     68-69:050-006

Desalination processes
     63-69:050-010

Demineralization
     68-69:050-010

Design
     68-69:02A-001
     68-69:02F-010
     68-69:03F-020
     68-69 .-06A-001
     68-69:068-006
Design criteria
     68-69:02E-002

Diatoms
     68-69:050-002

Dieldrin
     68-69:05A-009
Diffusion
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
020-007
020-013
02F-004
02F-027
02F-040
020-014
020-020
020-035
020-038
020-042
02G-045
020-046
020-049
020-060
02G-061
021-020
021-022
02K-013
02K-018
078-013
078-002
Diffusivity
     68-69 :02G-009
     68-69:020-010
     68-69:020-034
                    Diffusivity (Cont.)
                         68-69:020-045
                         68-69:020-051
                         68-69:020-060
                    Digestion
                         68-69:05E-003

                    Digital computers
                         68-69:020-013
                         68-69 :02E-007
                         68-69:02F-020
                         68-69:02F-021
                         68-69 .-02F-032
                         68-69:02F-036
                         68-69:02F-045
                         68-69:020-043
                         68-69:070-001
                    Jimensional analysis
                         68-69:068-006

                    Discharge  (Water)
                         68-69:02E-007
                         68-69:02F-013
                         68-69:02F-030
                         68-69 :02F-040
                         68-69:02G-023
                         68-69:056-023
                         68-69 :02F-014

                    Dispersing agents
                         68-69:038-001

                    Dispersion
                         68-69:02F-001
                         68-69 :02F-027
                         68-69--02F-038
                         68-69:020-039
                         68-69:020-061
                         68-69:058-023
Dissolved solids
     68-69 :02F-044
     68-69 :03A-001
     68-69.-03C-002
Distribution patterns
     68-69:02F-023
     68-69 :04A-003
     68-69 :04A-005
Distribution systems
     68-69 :02A-002
     68-69:04A-003
Ditches
     68-69:02A-001
     68-69:02F-021
     68-69:02F-024
     68-69 :02F-046

Diurnal
     68-69:020-016

Diurnal distribution
     68-69:020-010
                                      187

-------
 Drainage
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69:
      68-69;
      68-69:
      68-69:
      68-69:
      68-69:
      68-69:
      68-69 :
      68-69 :
      68-69:
      68-69:
      68-69:
      68-69:
      68-69:
      68-69:
      68-69:
      68-69:
      68-69:
      68-69:
:02F
:02F
:02F
:02F
:02F
:02F
:02F
:02F
:02F
:02G-
:02G-
:02G-
:02G-
:02J-
:02J-
:03C-
:03F-
:04A-
:04A-
:04A-
:04A-
:05B-
:05B-
:05D-
:05G-
;06B-
06E-
-003
-005
-006
-015
-017
-022
•040
•046
•005
•007
•029
•039
•044
•Oil
•013
•005
 022
 002
 008
 009
 Oil
 007
 015
 002
 006
 004
 004
 Drainage  effects
      68-69:02F-009
      68-69:02F-021
      68-69:02F-040
      68-69:02G-021
      68-69:02G-044
      68-69:05B-002
      68-69-.05G-003
      68-69:05B-027
 Drainage  engineering
      68-69:02A-001
      68-69:02F-006
      68-69-.02F-024
      68-69:02F-040
      68-69:02G-047
      68-69:05G-006
      68-69:02F-015
      68-69:058-027

Drainage  practices
      68-69:02A-001
      68-69:05G-006

Drainage  programs
      68-69:02A-001

Drain tiles
      68-69:02F-015

Drainage  systems
     68-69:02A-001
     68-69:02F-006
     68-69:02F-009
     68-69:02F-015
     68-69.-02F-016
     68-69:02F-024
     68-69-.02F-033
     68-69-.02F-046
     68-69:03F-020
     68-69:04A-011
     68-69:05G-006
     68-69:050-013
Drainage water
      68-69:02F-025
      68-69:02G-021
      68-69 :02G-024
      68-69:03C-003
      68-69:056-015
      68-69:05B-018
      68-69:05G-003
      68-69:05G-006
      68-69:058-027

Draindown
      68-69:02F-005
Drains
     68-69:02F-003
     68-69 :02F-015
     68-69:02F-033
     68-69 :02G-021
     68-69 .-02G-039
     68-69 :03F-020
     68-69:056-002
     68-69:058-018
     68-69:05G-003
Drawdown
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
                                :02E-001
                                :02F-01b
                                :02F-031
                                :02F-035
                                :02F-037
                                -.02F-040
                                :02F-049
                                :02G-023
                                :04A-011
                                :07C-001
                     Drilling
                           68-69:02F-002

                     Drilling equipment'
                           68-69:078-015

                     Droughts
                           68-69:03F-016
                           68-69:06E-002

                     Dry land farming
                           68-69:020-008

                     Drying
                           68-69:02G-029

                     Dunes
                           68-69:04A-009

                     Dupuit-Forchheimer theory
                           68-69:02F-019
                           68-69:02F-021
                           68-69.-02F-038
                           68-69:02F-041
                           68-69:02G-036
                           68-69:070-001

                     Duration curves
                           68-69:02E-007

                     Dye releases
                           68-69:02J-007
Dyes
      68-69:02F-034
      68-69:04A-010

Dynamic programming
      68-69:03F-013

Ecology
      68-69:05C-002
      68-69:04A-008

ticonomic justification
      68-69:03A-001

Economics
      68-69:02F-036
      68-69:04A-008
      68-69:058-006
      68-69:050-003
      68-69:068-003
      68-69:068-005
Effluents
     68-69 :02F-033

Ecosystems
     68-69.-05C-002

Ecotypes
     68-69:050-002

Electrical conductance
     68-69:02F-033
     68-69 .-02G-052
     68-69:030-002

Electrical conductivity
     68-69:03F-010

Electrical equipment
     68-69:02G-028

Electrical resistance
     68-69:02F-033
     68-69:04A-009

Electrical studies
     68-69:02F-011
     68-69:02F-014

Electrodialysis
     68-69:050-010

Electrolysis
     68-69 :02F-029

Electrolytes
     68-69:02G-017
     68-69:02G-034

Electronic equipment
     68-69:078-017

Elevation
     68-69:020-024

Embankments
     68-69 :02J-004
                                      188

-------
Endrin
     68-69.-02K-003
     68-69-.02J-003
Energy
     68-69:020-021

Energy budget
     68-69:020-001
     68-69:020-018
     68-69:020-012
     68-69:020-023
     68-69:021-020

Energy balance
     68-69:020-022
     68-69:020-018
Energy conversion
     68-69:020-029
Environmental effects
     68-69:020-026
     68-69:02G-051
     68-69:021-013
     68-69:04A-008
     68-69:05A-006
Equations
     68-69 :02E-002
     68-69 :02F-022
     68-69-.02F-032
     68-69:020-024
     68-69:02G-037
     68-69:02G-050
     68-69 .-02G-051
     68-69:03F-020
     68-69 :02G-039
     68-69:020-024

Equilibrium
     68-69:02G-017
     68-69 :02K-009
Equipment
     68-69:02F-010
     68-69:02G-028
     68-69 :05A-002
     68-69:06A-001
     68-69:07B-015
Erosion
     68-69:02G-013
     68-69 :02J-009
     68-69 :02J-011
     68-69 :02J-016
     68-69:02J-017
     68-69:03F-025
     68-69:05B-017
     68-69:056-005
     68-69.-05B-020
     68-69:056-021
Erosion control
     68-69:02E-004
     68-69 :02G-059
Erosion control  (Cont.)
     68-69:02J-004
     68-69:02J-008
     68-69 .-02J-010
     68-69:02J-012
     68-69:02J-014
     68-69:02J-016
     68-69:068-005
Estimating
     68-69:020-002
     68-69:020-020
     68-69:02E-008
                                Estuaries
                                     68-69:04A-008
Ethanol
     68-69:05F-002

Eutrophication
     68-69 :02J-002
     68-69:056-004
     68-69:056-006
     68-69:056-008
     68-69:056-022
     68-69:05F-002
     68-69:056-027

Evaluation
     68-69:02A-001
     68-69:02G-067
Evaporation
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     6S-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69 :
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
020-001
020-002
020-003
020-006
020-008
020-012
020-013
020-014
020-015
020-018
020-020
020-021
020-022
020-028
02E-007
02F-030
02G-009
02G-010
02G-020
02G-035
021-020
030-001
03F-012
03F-018
03F-025
07A-001
076-005
020-005
03F-011
Evaporation Control
     68-69:020-006
     68-69:020-010
     68-69:020-011
                    Evaporation control
                      (Cont.)
                         68-69 :02G-048
                         68-69:02G-051
                         68-69:03F-017
                         68-69:05C-004
                    Evaporation pans
                         68-69:020-002
                         68-69:020-021
                         68-69:02D-024
                         68-69 .-03F-018
                         68-69:03F-030
                         68-69 :05C-004
                         68-69:066-003
Evaporators
     68-69:020-001

Evapotranspiration
     68-69:020-001
     68-69:020-002
     68-69:020-004
     68-69:020-008
     68-69 :02D-012
     68-69:020-015
     68-69:020-016
     68-69 :02D-017
     68-69:020-018
     68-69:020-021
     68-69:020-022
     68-69:020-023
     68-69 :02D-024
     68-69 :02D-026
     68-69:020-027
     68-69.-020-028
     68-69 :02F-013
     68-69:02G-021
     68-69:02G-023
     68-69 :02G-042
     68-69 :02I-008
     68-69:021-012
     68-69:021-016
     68-69 :02I-020
     68-69:030-001
     68-69:03F-014
     68-69:03F-018
     68-69:03F-030
     68-69 :04A-007
     68-69:058-002
     68-69:078-013
     68-69:020-005
     68-69:03F-011

Evapotranspiration con-
   trol
     68-69:020-019

Excavation
     68-69:02F-017

Expansive clays
     68-69 .-02G-019
     68-69:02G-061

Expansive soils
     68-69 :02G-019
     68-69 :02G-061
                                      189

-------
 Experimental data
      68-69:02G-013

 Experimentation
      68-69:05G-002
 Fallowing
      68-69 -.020-015
      68-69 :05C-004
 Farm equipment
      68-69:02E-002
      68-69:04A-006
 Fibers (Plant)
      68-69:021-011

 Field tests
      68-69 :02F-034
      68-69-.02G-013
      68-69:03F-001
 Filters
      68-69:02F-003
      68-69:02F-04 5
      68-69:05F-003
      68-69:05F-004
Flow measurement
     68-69:02F-033
     68-69:02G-035
Flow rates
     68-69 .-02E-002
     68-69 :02F-010
     68-69:02G-017
     68-69:02G-050
Flowmeters
     68-69:076-017
 Farm  management
      68-69:02J-004
      68-69:02J-014
      68-69.-05B-004
      68-69:050-003

 Farm  ponds
      68-69:02K-008
Farm lagoons
     68-69:05G-004

Farm wastes
     68-69:05B-005
     68-69 -.05C-003
     68-69:05C-005
     68-69:05G-004
     68-69:05B-022

Farming
     68-69:03F-012
Farms
     68-69:05B-005
     68-69:05B-021
Fertilization
     68-69 :02I-003
     68-69:02I-007
     68-69 :02I-010
     68-69 :02I-012
     68-69 :03F-027
     68-69:053-013
Fertilizers
     68-69-.02F-050
     68-69:02G-069
     68-69:021-005
     68-69:02K-004
     68-69:02K-016
     68-69:02K-017
     68-69:058-004
     68-69:058-006
     68-69:058-008
     68-69:058-014
     68-69:05B-018
     68-69:05B-020
     68-69:05B-022
     68-69:058-026
     68-69 :05C-001
     68-69 :05C-005
     68-69:05E-003
     68-69:05G-004
     68-69 :05B-015
Filtration
      68-69 :02F-039
      68-69:02G-029
      68-69:05A-008
      68-69:050-004
      68-69:050-009
      68-69:05E-004
      68-69:05F-003
      68-69:05F-004
Fish
      68-69:04A-008

Fishkill
      68-69:05C-005

Flocculation
      68-69:050-008
Flood control
     68-69:02J-013
     68-69:04A-008
     68-69:068-004
                                Flood  irrigation
                                     68-69:021-010
Flooding
     68-69:02F-037
     68-69:02G-007
     68-69:02G-029
     68-69:02I-023
Florida
     68-69:04A-008
Flow
     68-69:02F-020
     68-69:02F-027
     68-69:02G-006
     68-69:02G-014
     68-69:02J-010
     68-69 .-03F-003
Flow characteristics
     68-69:020-062
Fluid flow
     68-69:02E-001
Fluid mechanics
     68-69:02F-027
     68-69:02G-035
                                                                Forages
                                                                     68-69 :03F-008
Forecasting
     68-69:04A-003
     68-69:04A-007
     68-69:03F-016

Foods
     68-69:050-006

Forest management
     68-69 :02D-019

Forest soils
     68-69:02K-016

Forests
     68-69:020-019
Free energy
     68-69:078-023

Freezing
     68-69:02F-006
     68-69:02G-032

Fresh water
     68-69:02F-044

Furrow irrigation
     68-69:02G-069
     68-69:03F-001
     68-69-.03F-003
     68-69 .-03F-022
     68-69:04A-006
     68-69:05B-014
Furrow systems
     68-69:02J-008

Furrows
     68-69:03F-001
     68-69 :03F-003
                                       190

-------
Gamma rays
     68-69 .-02G-054
     68-69:02G-068
     68-69:02J-009
     68-69:076-009
     68-69 :07B-010
Gas liquid chromatographic
  techniques
     68-69:05A-005

Gate control
     68-69 :03F-001
Geochemistry
     68-69:02F-044

Geologic mapping
     68-69:07B-021

Geology
     68-69:076-021

Geomorphology
     68-69:040-001

Geophysics
     68-69:02F-001
     68-69:02F-014
     68-69:076-021

Germination
     68-69:021-021
     68-69:030-001
     68-69:03C-004
     68-69:03F-010
Government supports
     68-69:05B-006

Governments
     68-69:02J-014

Grading
     68-69:02J-008

Grains  (Crops)
     68-69:02K-005

Grasses
     68-69:02J-012

Grasslands
     68-69:02E-006
     68-69:050-006
     68-69:02F-050
Gravitational water
     68-69:04A-002

Great Plains
     68-69 .-02D-022
     68-69:02E-006

Great Plains  (Nebr)
     68-69:021-017

Groundwater
     68-69:02E-001
     68-69:02F-001
Groundwater
     68-69 :
     68-69:
     68-69 :
     68-69:
     68-69 :
     68-69:
     68-69:
     68-69 :
     68-69:
     68-69:
     68-69 :
     68-69:
     68-69 :
     68-69:
     68-69:
     68-69 :
     68-69:
     68-69 :
     68-69:
     68-69 :
     €8-69 :
     €8-69:
     68-69:
     68-69 :
     68-69 :
     68-69 :
     68-69:
     68-69:
     68-69 :
     68-69:
     68-69 :
     68-69:
     68-69 :
     68-69:
Groundwater
     68-69:
     68-69 :
     68-69:
 (Cont.)
02F-003
02F-005
02F-007
02F-009
02F-013
02F-014
02F-016
02F-018
02F-023
02F-035
02F-039
02F-042
02F-047
02F-049
02F-05Q
02K-001
03C-002
04A-010
04A-006
056-008
056-010
056-024
05B-026
05C-001
05C-003
05G-004
05G-010
076-003
07B-016
07B-021
05B-027
05G-013
02F-034
07B-pl8
 basins
02F-032
02F-036
02F-039
Groundwater flow
     68-69 :02E-001
     68-69 :02F-034
     68-69 :02F-039

Groundwater mining
     68-69:02F-039
Groundwater
     68-69 :
     68-69:
     68-69 :
     68-69 :
     68-69 :
     68-69 :
     68-69:
     68-69 :
     68-69 :
     68-69 :
     68-69:
     68-69 :
     68-69:
     68-69 :
     68-69 :
     68-69:
     68-69:
     68-69:
     68-69:
     68-69 :
     68-69 :
     63-69 :
 movement
02A-001
02F-013
02F-017
02F-020
02F-024
02F-027
02F-029
02F-030
02F-031
02F-041
02F-043
02G-043
02G-046
02G-049
02G-056
02G-064
02G-065
02G-066
021-016
05B-023
05D-004
05E-004
                    Groundwater movement
                      (Cont.)
                         68-69 :05E-004
                         68-69:073-018
                         68-69 :07C-001
                         68-69 :02F-039

                    Groundwater recharge
                         68-69 :02F-028
                         68-69 :02F-039
                         68-69--04A-010
                         68-69 :05B-026
                    Growth chambers
                         68-69 :02I-019
                    Growth rates
                         68-69:020-029
                         68-69 :02I-013
                    Growth stages
                         68-69:02G-026
                         68-69 :03C-004
                         68-69 :03F-006
                         68-69:03F-013
                    Gully erosion
                         68-69:02J-007
                    Half life
                         68-69 :02J-009

                    Halophytes
                         68-69 :05C-002

                    Hand resources
                         68-69 :06B-005

                    Hardness  (Water)
                         68-69 :08A-001

                    Head loss
                         68-69:02J-003
                    Heat balance
                         68-69:020-001

                    Heat budget
                         68-69 :02D-013
                         68-69.-07A-001
                    Heat flow
                         68-69 :02D-003
                         68-69 :02D-018

                    Heat transfer
                         68-69 :02G-049

                    Heated water
                         68-69:020-014

                    Heptachlor
                         68-69:02K-003
                         68-69 :05A-009
                         68-69 :05B-015
                                      191

-------
 Herbicides
      68-69 :02F-006
      68-69:02K-018
      68-69 :03F-024
      68-69:04A-012
      68-69:05A-006
      68-69 :05C-003
      68-69 :05C-005
 Hexadecanol
      68-69 :02G-041

 Highways
      68-69:02F-005
      68-69:06E-004
 Humidify
      68-69:02D-001
      68-69:020-012
      68-69:02D-024

 Humic acids
      68-69:02K-010
      68-69:03F-006
 Hydraulic
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
conductivity
:02F-017
:02F-024
:02F-041
:02F-043
:02G-017
.•02G-019
:02G-030
:02G-044
:02G-045
:02G-046
:02G-047
-.02G-061
:02G-064
:02G-063
.•02G-065
:02G-071
:07B-004
:02G-070
Hydraulic gates
     68-69:04A-006

Hydraulic gates and  valves
     68-69.-03F-001

Hydraulic models
     68-69 :02F-038
     68-69:02F-043
     68-69:02G-022
     68-69 :02G-036
Hydraulics
     68-69:02F-018
     68-69:03F-019
Hydrodynamics
     68-69 :Q2F-004
     68-69:02F-04 8
     68-69:03F-003
                       Hydrogen ion concentration
                            68-69:02J-012
                            68-69:030-002
                            68-69:030-003

                       Hydrogen sulfide
                            68-69:02F-046
                            68-69 .-02K-012
                      Hydrogeology
                           68-69 :02F-011
                           68-69:02F-044
                           68-69:04A-010
                           68-69:05E-004
                           68-69:07B-021
 Hydrograph  analysis
      68-69 :02E-007
      68-69 :02F-026

 Hydrographs
      68-69 .-02E-007
      68-69:04A-010

 Hydrologic  aspects
      68-69:68-69:07A-001

 Hydrologic  budget
      68-69:02D-013
      68-69:02D-016
      68-69 :02E-007
      68-69:02F-013
      68-69:02G-023
Hydrologic cycle
     68-69 :02G-054
     68-69:03D-001

Hydrologic data
     68-69:02F-032
     68-69:050-012

Hydrologic properties
     68-69:078-011

Hydrology
     68-69:020-022
     68-69.-02G-013
     68-69:02G-054
     68-69:040-001

Hydrolysis
     68-69:07A-001

Hydrostatic pressure
     68-69:021-014

Hygrometry
     68-69:020-016
     68-69:02I-022
     68-69:03F-006
     68-69 :07B-014
     68-69 :07B-023
                      Hypolimnion
                           68-69:050-009
                                Hysteresis
                                     68-69:02G-011
                                     68-69:02G-020
                                     68-69:02G-029
                                     68-69:02G-044
Idaho
     68-69:02A-002
     68-69:02E-002
     68-69:04A-010

Illinois
     68-69:04A-007

Impact  (Rainfall)
     68-69:02G-008
     68-69 :02G-063
     68-69:02G-070
     68-69 :02J-005
     68-69:02J-006
     68-69:02J-016
                                                     Impaired water quality
                                                           68-69:050-010
Impervious soils
     68-69 :02G-061

Industrial wastes
     68-69.-05B-006
     68-69:05D-006
Infiltration
     68-69:02A-002
     68-69:02E-007
     68-69:02E-008
     68-69:02E-009
     68-69.-02F-019
     68-69:02F-013
     68-69:02F-030
     68-69:02F-040
     68-69:020-003
     68-69:020-008
     68-69:020-009
     68-69:02G-013
     68-69:02G-020
     68-69:020-022
     68-69 :02G-025
     68-69:020-029
     68-69:020-030
     68-69:02G-033
     68-69:020-047
     68-69:020-059
     68-69:020-062
     68-69:020-063
     68-69:02G-064
     68-69:020-065
     68-69:020-070
     68-69:020-071
     68-69:03F-003
     68-69:03F-019
     68-69:03F-030
     68-69 :04A-002
     68-69:04A-004
     68-69 .-04A-010
     68-69:040-001
                                      192

-------
Filtration  (Cont.)
     68-69:05E-003
     68-69:05E-004
     68-69:078-013
Infiltrometers
     68-69:04A-010
Inflow
     68-69:02E-007
     68-69:02F-017
Infrared radiation
     68-69:02G-048
Inhibitors
     68-69:021-021

Injection
     68-69:050-002

Injection wells
     68-69:02F-041
Input-output analysis
     68-69.-02F-032
     68-69:02G-021
Insecticides
     68-69:02K-003
     68-69:05A-007
     68-69:05A-009
     68-69:050-003
     68-69.-05B-026
Inspection
     68-69:06A-001
Institutional constraints
     68-69:06E-003
Instrumentation
     68-69:020-021
     68-69:02F-002
     68-69:02F-012
     68-69:02G-016
     68-69:02G-028
     68-69:02G-038
     68-69 .-02G-047
     68-69:0?G-050
     68-69:02G-052
     68-69:05A-002
     68-69:078-006
     68-69.-07B-007
     68-69:07B-009
     68-69:07B-010
     68-69:076-011
     68-69 .-07B-012
     68-69:076-014
     68-69:076-016
     68-69:076-017
     68-69:078-019
Instrumentation  (Cont.)
     68-69:078-020
     68-69:07B-022
     68-69:07B-023
Interfaces
     68-69:02F-043
     68-69:02G-040
Interstate
     68-69:06E-002

Interstate compacts
     68-69:06E-002
Interstices
     68-69 :02F-031

Investigation
     63-69:06A-001

Ion exchange
     68-69:02F-004
     68-69:02F-023
     68-69:02G-019
     68-69:02G-034
     68-69 :02G-061

Ion transport
     68-69 .-02G-034
     68-69 :02G-046
     68-69:02G-049
     68-69:076-002
Ions
     68-69 :02G-021
     68-69:02K-011
Iowa
     68-69 :02D-020

Irrigated land
     68-69:02D-023
     68-69 :02G-021
Irrigation
     68-69:
     68-69:
     68-69:
     68-69:
     68-69 :
     68-69:
     68-69:
     68-69:
     68-69 :
     68-69 :
     68-69 :
     68-69 :
     68-69:
     68-69 :
     58-69 :
     68-69 :
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
02D-010
02D-014
02D-018
02F-005
02F-008
02F-009
02G-004
02G-009
02G-010
02G-019
02G-023
02G-025
02G-028
02G-029
02G-030
02G-050
021-002
021-003
021-005
021-006
021-009
021-012
021-016
                    Irrigation
                         68-69;
                         68-69:
                         68-69:
                         68-69:
                         68-69:
                         68-69:
                         68-69:
                         68-69:
                         68-69:
                         68-69;
                         68-69:
                         68-69:
                         68-69:
                         68-69:
                         68-69:
                         68-69;
                         68-69:
                         68-69:
                         68-69:
                         68-69;
                         68-69;
                         68-69:
                         68-69:
                         68-69:
                         68-69:
                         68-69;
                         68-69:
                         68-69;
                         68-69:
                         68-69;
           (Cont.)
           03C-004
           03C-005
           03F-001
           03F-004
           03F-005
           03F-007
           03F-008
           03F-009
           03F-011
           03F-012
           03F-016
           03F-022
           03F-023
           03F-027
           03F-028
           03F-030
           04A-004
           04A-006
           04A-008
           04A-009
           05B-002
           05B-010
           05B-014
           05D-006
           05D-010
           05E-003
           05E-004
           05G-004
           066-003
           03F-001
                    Irrigation canals
                         68-69:03F-001
                         68-69:04A-012
                         68-69 :08A-001
                    Irrigation design
                         68-69:02E-008
                         68-69.-02F-010
                         68-69:02G-040
                         68-69:02G-047
                         68-69:03F-001
                         68-69:03F-003
                         68-69:03F-005
                         68-69:04A-003
Irrigation
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
Irrigation
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
 effects
:02D-023
:02G-021
:02I-008
:02I-009
:02I-014
:02I-019
:03C-005
:03F-006
:05B-027
 efficiency
:02A-002
:02D-017
:02E-002
:02E-008
:02G-025
:02G-026
:02I-008
:02I-011
:02I-016
:02I-017
:02J-008
:03F-005
                                      193

-------
 Irrigation efficiency  (Cont.)
      68-69 :03F-013
      68-69:03F-Oi7
      68-69 -.03F-020
      68-69:03F-Q27
      68-69 :C3F-028
      68-69:04A-003
      68-69:04A-007
 Irrigation engineering
      68-69:02E-002
      68-69:02F-009
      63-69:03F-OC3
      68-69:03F-005
      68-69:04A-006
 Irrigation operation and
   maintenance
      68-69:02F-015
      68-69:04A-012
 Irrigation
     "68-69
      68-69
      63-69
      68-69
      68-69
      63-69
      68-69
      68-69
      68-69
      63-69
      68-6S
      63-69
      68-69
      68-69
      68-69
      68-69
      68-69
 prac
:02E-
:02G-
:02G-
:02J-
:03C-
:03F-
:03F-
:03F-
:03F-
:03F-
:C4A-
:04A-
:G5B-
: 05D-
: 05G-
:06E-
: 0 5 B -
:tlces
•008
•025
•027
•013
•005
014
005
017
027
030
005
007
014
001
004
003
028
                  Irrigation
                       68-69
                       68-69
                       68-69
                       68-69
                       68-69 -.
                       68-69:
                       68-69 :
                       68-69:
                       68-69 :
                       68-69 :
                       68-69 :
                       68-69 :
                       68-69:
                       68-69 :
                       68-69 :
                                  water (Cont.)
                                 :02G-026
                                 :02G-039
                                 :02G-069
                                 :02G-024
                                 -.021-016
                                 :030-003
                                 :03F-013
                                 :03F-020
                                 :04A-007
                                 :05C-003
                                 :05D-001
                                 :05G-010
                                 :050-012
                                  06B-001
                                  08A-001
                                                                 Lake soils
                                                                      68-69:078-008
                      Irrigation water  treat
                        ment
                            68-69:050-003
                                 Iron
                                      68-69 :02K-015
                                      68-69:05A-008

                                 Iron bacteria
                                      68-69:02F-015
                                      68-69:02F-046

                                 Iron compounds
                                      68-69:02F-046
                                 Iron oxides
                                      68-69:02F
                                               -01!
                                 Isotherms
                                      68-69:02I-013
                                               -054
                                                                 Lakes
                                                                      68-69:02  -013
                                                                      68-69:05A-008
                                                                      68-69 :05G-010
                                                                      68-69 :07B-008
                                                                 Land
                                                                      68-69 :03F-001
Land disposal
     68-69 :05E-002

Land farming
     68-69:06B-005

Land forming
     68-69:02J-004

Land management
     68-69 .-02G-049
     68-69 :02J-004
     68-69:02J-014
     68-69:04A-011
     68-69:05B-004
     68-69:06B-005
     68-69:06E-003
Land reclamation
     68-69:02J-013
     68-69 :03C-005
                                                                Land treatment
                                                                     68-69 :02J-010
Irrigation programs
     68-69 :03F-013
     68-69:03F-030
     68-69:05B-027

Irriqation return water
    "68-69 :02K-007
Irrigation systems
     63-69:02A-G02
     68-69 :02E-002
     63-69 :02E-003
     68-69:02F-OiO
     68-69 :02G-040
     68-69 :03F-001
                      Isotopes
                           68-69:02G-054
Irrigation water
     68-59 :02E-002
     68-C9 : 02F-025
     63-69:02F-037
     68-69:02G-017
     6a-69:02G-025
                           68-69:07B-018

                      Kinetics
                           68-69:021-013
                           68-69:02I-015

                      Laboratory tests
                           68-69:02F-028
                           68-69:02F-029
                           68-69 :02G-034
                           68-69:02G-054
                           63-69 :'j2G-Cei
                           58-63:0 2 3 -C11
                           63-69 -.04A-004
                                                 Land use
                                                      68-69:02D-004
                                                      68-69 -.02E-006
                                                 Laplaces equation
                                                      68-69:04A-011
                                                                Larvas
                                                                     68-69.-02K-007
                                                                Laterals
                                                                     68-69
                                                                     68-69
                                                                     68-69
                                                            02A-002
                                                            03F-002
                                                            04A-003
                                                 Leachincr
                                                      68-69:020-017
                                                      68-69 :Q2G-019
                                                      68-69:02G-021
                                                      68-69:02G-024
                                                      68-69:02G-039
                                                      68-69:02G-049
                                                      68-69:02J-013
                                                      68-69:02K-004
                                                      68-69.-02K-010
                                                      68-69:02K-019

-------
Leaching  (Cont.)
     68-69.-03C-003
     68-69:030-005
     68-69.-03F-020
     68-69:03F-030
     68-69:05A-007
     68-69:05B-003
     68-69 :05B-017
     68-69:05B-020
     68-69:05C-001
     68-69:050-002
     68-69:05G-013

Leaching Urea
     68-69:02K-016
Leakage
     68-69:02F-042
     68-69:078-018
Leaves
     68-69:02I-013

Legislation
     68-69 :05B-004
     68-69:050-005
     68-69:063-004
Legumes
     68-69:021-008
     68-69:02K-020
Lime
     68-69 .-02G-024

Livestock
     68-69:05B-021
Loam
     68-69:02F-009
     68-69:02G-015
     68-69:030003
     68-69.-05G-007
Loess
     68-69:04A-010

Logging
     68-69:07B-021

Local governments
     68-59.-06E-002

Long-term planning
     68-69:06E-002

Low flow
     68-69:03F-016

Lysimeters
     68-69:020-002
     68-69:020-008
     68-69:02F^008
     68-69:02F-025
     68-69:02G-009
     68-69:020-028
     68-69:021-016
Lysimeters  (Cont.)
      68-69:02K-016
      68-69:03C-003
      68-69:07B-006
      68-69:078-013
Macrobenthos
     68-69 :02K-007

Magnesium
     68-69:02G-069
     68-69:02K-019
     68-69:030-003
     68-69:05A-001

Management
     68-69 :03F-005
     68-69:03F-012
     68-69.-03F-021
     68-69 :06B-003
Manganese
     68-69:02G-005
     68-69:02K-017
Manganese compounds
     68-69:02F-015

Measurement
     68-69 :02G-028

Mapping
     68-69:05B-007

Marginal benefits
     68-69:03A-001

Marginal costs
     68-69:03A-001
Mass transfer
     68-69:020-001
     68-69:020-013
     68-69:02F-027
     68-69:02G-046
     68-69 :02G-049
     68-69:02G-060
Manometers
     68-69:02G-028
Mathematical models
     68-69:020-001
     68-69:020-013
     68-69:020-024
     68-69:02E-007
     68-69:02E-009
     68-69:02F-019
     68-69:02F-020
     68-69:02F-024
     68-69:02F-030
     68-69:02F-032
     68-69:02G-022
     68-69:02F-036
     68-69:02G-030
Mathematical models
     68-69.-02G-036
     68-69 :02G-042
     68-69:020-043
     68-69:02G-056
     68-69:03A-001
     68-69:03F-003
     68-69:03F-013
     68-69:03F-019
     68-69 :06B-006
     68-69 .-07C-001
     68-69-.05G-013

Mathematical studies
     68-69 :02A-001
     68-69 :02F-018
     68-69 :02F-020
     68-69:02F-040
     68-69:02G-023
     68-69.-02G-029
     68-69:02G-030
     68-69:02G-045
     68-69-.02G-056
     68-69:04A-011
Mayflies
     68-69:02K-007

Measurements
     68-69:02G-047
     68-69:02J-003
     68-69:02G-072
Mechanization
     68-69:04A-006

Meteoric water
     68-69:020-001
     68-69:030-001

Meteorology
     68-69:020-001
     68-69:020-012
     68-69:02G-018
Methanol
     68-69:05F-002

Methodology
     68-69:02E-001
     68-69 .-07A-001
     68-69:07B-011
Microclimatology
     68-69:020-023
     68-69:03F-006
Microenvironment
     68-69:020-001
     68-69:021-014

Microorganisms
     68-69:02K-020
Millet
     68-69:020-008
                                      195

-------
 Meteorological  data
      68-69:020-005
      68-69:020-015
 Mineralogy
      68-69:020-017
 Mixing
      68-69:02F-027
      68-69:02G-055
Model  studies
     68-69:02A-001
     68-69:020-004
     68-69:020-015
     68-69:020-016
     68-69:020-018
     68-69:020-029
     68-69:02E-007
     68-69:02E-009
     68-69:02F-019
     68-69:02F-022
     68-69:02F-026
     68-69:02F-033
     68-69:02F-036
     68-69:02F-045
     68-69:020-014
     68-69:020-022
     68-69:020-055
     68-69:020-063
     68-69:020-070
     68-69:02J-007
     68-69:02J-011
     68-69:03F-028
     68-69:04A-009
     68-69:05E-005
     68-69:068-006
     68-69:050-013

Model  tests
     68-69:02F-034
Models
     68-69:02J-003

Mohr circle
     68-69:02F-018

Moisture
     68-69:020-033

Moisture availability
     68-69:020-005
     68-69:020-020
     68-69:020-027
     68-69:020-026

Moisture content
     68-69:020-016
     68-69:020-018
     68-69:020-020
     68-69:020-051
     68-69:02G-072
     68-69:020-065
     68-69:020-071
     68-69:021-004
     68-69:021-006
     68-69:02K-004
     68-69:02K-013
Moisture content  (Cont.)
      68-69:07B-007
      68-69:078-015
      68-69:078-020
      68-69:078-022
Moisture deficit
     68-69:020-017
     68-69-.02D-026
     68-69:020-026
Moisture meters
     68-69:078-020
Moisture stress
     68-69:020-016
     68-69:020-020
     68-69:020-026
     68-69:020-038
     68-69:021-006
     68-69:021-013
     68-69:021-022
Moisture tension
     68-69:02F-043
     68-69:020-027
     68-69:020-028
     68-69:020-038
     68-69:020-057
     68-69:020-065
     68-69:020-071
     68-69:058-009
     68-69:078-011
     68-69:07B-013
Moisture uptake
     68-69:020-016
     68-69:021-019
                                Molybdenum
                                      68-69:02K-017
Momentum equation
     68-69:020-006
Monitoring
     68-69:020-028

Monomolecular films
     68-69:03F-011

Monthly
     68-69:020-021

Montmorillonite
     68-69:020-061
Movable dams
     68-69:04A-006

Movement
     68-69 :02F-023
     68-69:020-054
Muck soils
     68-69:02F-006

Mulching
     68-69:020-006
     68-69:020-001
     68-69:020-015
     68-69:020-032
     68-69:020-048
     68-69:02J-016
     68-69:03F-021
     68-69:03F-024

Municipal wastes
     68-69:058-006

Municipal water
     68-69:06E-002
Nebraska
     68-69:02E-006
Nematodes
     68-69:05F-003
     68-69:05F-004
Neutron absorption
     68-69:078-015

Neutron meters
     68-69:020-072

Nevada
     68-69:020-002

New York
     68-69:03F-016
Nitrates
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69
02F-
02F-
020-
02J-
02K-
03C-
058-
05B-
058-
058-
05B-
05B-
05C-
05C-
050-
050-
050-
;05B-
016
050
069
003
009
002
009
014
018
021
023
026
001
005
002
•003
•009
•027
Nitrate removal
     68-69:05E-001

Nitrification
     68-69:02K-006
     68-69:02K-009
     68-69:02K-014
     68-69.-05B-009
                                      195

-------
 Plant growth
      68-69:02F-025
      68-69 :02I-011
      68-69:02I-013
      68-69:02I-015
      68-69:021-021
      68-69:03C-001
      68-69:030-004
      68-69:03F-030
      68-69:02D-029
 Plant growth substances
      68-69:02D-029
      68-69:021-021
      68-69:05B-017
 Plant physiology
      68-69:020-026
      68-69:020-029
      68-69:02G-026
      68-69:02G-050
      68-69:021-003
      68-69:021-013
      68-69:021-014
      68-69:021-015
      68-69:030001
      68-69:030-004
      68-69:03F-030
      68-69:05B-013
Plant populations
     68-69:021-004
     68-69:03F-023

Plant tissue
     68-69:076-005

Planting management
     68-69:02E-004
     68-69:058-017

Plants
     68-69:020-012
     68-69:03F-011
     68-69:04A  008
Plastic pipes
     68-69:03F-029
Plasticity index
     68-69:036-001
Plastics
     68-69:02F-010
Playas
     68-69:03C-002
 Pollutant identification
      68-69 :05B-011
 Pollutants
      68-69:02J-003
      68-69:030-001
      68-69:05A-004
      68-69:05A-006
      68-69 :05B-015
      68-69:05C-001
      68-69:050-003
 Pollution
      68-69 :02F-007
      68-69:02K-001
      68-69:05D-008
      68-69:05G-006
Pollution  abatement
      68-69:058-015
      68-69:050-003
Ponding
      68-69:02G-039
                                 Ponds
     68-69:02K-008
     68-69:03B-001
     68-69:04A-012
     68-69:050-002
     68-69:07B-008
Pondweeds
     68-69:04A-012
Pore pressure
     68-69:02F-022
     68-69:02G-055
                                 Pores
     68-69:02G-025
     68-69:02G-064
Porosity
     68-69 :02F-014
     68-69 :02F-031
     68-69:02G-019
     68-69 :02G-036
     68-69 :02G-037
     68-69 :02F-038
     68-69 :02G-059
     68-69 :02J-012
     68-69 :04A-002
     68-69:05E-004
Porous
     68
     68
     68
     68
     68
     68
     68
     68
     68
     68
     68
     68
     68
     68
     68
     68
     68
     68
     68
       media
       -69:02F-001
       -69:02F-018
       -69:02F-020
       -69 :02F-022
       -69:02F-027
       -69 :02F-038
       -69 :02G-036
       -69:02G-037
       -69 :02G-043
       -69 :02G-045
       -69 :02G-055
       -69:02G-057
       -69:02G-062
       -69 :02G-064
       -69 :02G-065
       -69:02G-071
       -69 :04A-011
       -69:050-009
       -69:07B-017
Porous media clays
     68-69:02F-048

Potable water
     68-69:05F-004
Potassium
     68-69:02F-007
     68-69:02K-001
     68-69:02K-013
     68-69:02K-017
     68-69:05A-001
     68-69:05B-008
     68-69:076-006
Potassium compounds
     68-69:02K-014
     68-69:056-003
Potential flow
     68-69:020-057
Prairie soils
     68-69:03F-015

Precipitation
     68-69:03F-012
     68-69:03F-025
Precipitation (Atmos-
  pheric)
     68-69:02D-017
     68-69:020-020
     68-69:02F-013
     68-69:02G-026
     68-69:030-001
     68-69:050-004
     68-69:05G-010
Podsols
     68-69:07B-006

Political constraints
     68-69:06E-003
Porous materials
     68-69 :02F-034
Precipitation intensity
     68-69:02E-007
                                      198

-------
 Pressure
      68-69:020-028
      68-69:078-016
Pressure  head
      68-69:020-011
Pressure  measuring  instruments
      68-69:07B-019
Prices
      68-69:050-011
Radioactive isotopes
     68-69:02F-034
Radioactivity
     68-69:02F-007
     68-69:02F-012
     68-69:02F-044
     68-69:02J-009
     68-69:078-015
Radioactivity techniques
     68-69:02G-056
     68-69:02J-005
     68-69:02J-006
                    Range management
                         68-69:021-021
                                                               Ranges
                                                                    68-69:021-021
                    Rates of application
                         68-69:02A-002
                         68-69:02E-008
                         68-69:02G-025
                         68-69:02G-026
                         68-69:03F-013
                         68-69:03F-020
                         68-69:050-004
Prior appropriation
     68-69:06E-002
Productivity
     68-69:021-007
     68-69 .-05B-022
Programs
     68-69:03F-012
Projects
     68-69:068-002

Protein
     68-69:021-003

Provenance
     68-69.-05B-003

Public health
     68-69:03F-029
     68-69:05F-004
Public rights
     68-69:04A-008
Pumping
     68-69:02E-001
     68-69:02F-005
     68-69:02F-035
     68-69:058-023
Pumping plants
     68-69:02E-002
     68-69:03F-001
Radio-chemical analysis
     68-69:02F-029
Radioisotopes
     68-69 .-02F-023
     68-69:02G-054
     68-69:02J-009
     68-69:05B-017
Raindrops
     68-69 .-02G-063
     68-69:02J-005
     58-69:02J-006
Rainfall
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69;
     68-69:
     68-69:
     68-69
     68-69
     68-69:
     68-69:
02D-026
02G-004
02G-010
02J-003
02J-005
02J-006
02J-011
02J-017
021-017
03F-012
03F-018
04A-007
04D-001
058-007
Rainfall disposition
     68-69:02F-026
Rainfall intensity
     68-69:02F-030
     68-69:02J-007
                    Recession curves
                         68-69:02F-040
                         68-69:03F-019
                    Recharge
                         68-69:02F-013
                         68-69:02F-026
                         68-69:02F-030
                         68-69:020-029
                         68-69:03F-015
                         68-69:058-023
                         68-69.-05B-026
                    Reclaimed water
                         68-69:02F-047
                         68-69:050-001
                         68-69:050-005
Reclamation
     68-69:02F-006
     68-69:02K-011
     68-69:050-001
Recreation
     68-69:050-005
     68-69:05G-011

Recreation demand
     68-69:050-011
                                                                Recreation  facilities
                                                                     68-69:05G-011
                    Reduction
                         68-69:02K-002
Quality control
     68-69 .-02F-039
     68-69:030-001
     68-69:03F-029
Radiation
     68-69:020-010
     68-69:020-018
Radiation measurement
     68-69:02J-009
Rainfall-runoff relation-
  ships
     68-69:020-016
     68-69:02E-006
     68-69:02E-007
     68-69:02F-026
     68-69:02G-059
     68-69 .-02J-011
                    Regression analysis
                         68-69:020-026
                         68-69:02F-022
                         68-69:02G-018
                         68-69:020-037
                         68-69:020-062
                         68-69:04A-007
                               Regulation
                                    68-69:050-005
                                    68-69:058-004
                                      199

-------
 Removal
      68-69:05F-002
 Reverse  osmosis
      68-69:050-010
Routing
      68-69 :02E-009
 Research equipment
      68-69:02J-009
      68-69:07B-017
 Research  and  development
      68-69:07B-017
 Reservoir  leakage
      68-69:02K-008
      68-69:03B-001
Reservoir  silting
      68-69:02J-015
Reservoir  storage
      68-69:02J-015
Reservoirs
      68-69:020-013
      68-69:02K-008
      68-69:03B-001
      68-69:04A-004
      68-69:05G-010
Residues
     68-69:02K-003
Reviews
      68-69:020-056
      68-69:05B-004
Rice
      68-69:02D-010
      68-69:02I-004
      68-69:021-010
      68-69:03F-010
Rill erosion
     68-69:02J-007
     68-69:02J-016
Riparian  rights
     68-69:06E-002
Rio Grande
     68-69:06E-003
River flow
     68-69:03A-001
                                 Rivers
                                      68-69 :05G-010
Runoff
     68-
     68-
     68-
     68-
     68-
     68-
     68-
     68-
     68-
     68-
     68-
     68-
69 :02D-016
69 :02E-002
69 :02E-004
69 :02E-005
69 :02E-006
69:02E-008
69 :02F-026
69:02G-008
69:02G-013
69 :02G-015
69 :02G-030
69:026-059
   02J-003
   02J-007
        -69 :
        -69 :
                                                                     68
                                                                     68-69 :02J-008
                                                                       3-69
     68
     68
     68
     68-
     68-
     68-
     68-
     68-
     68-
     68-
     68-
     68-
     68-
   02J-012
69 :02J-016
69 :02J-017
69:03C-002
69 :03F-003
69 :03F-025
69:040-001
69 :05A-006
69 :05B-003
69:05B-014
69:05B-017
69 :05B-Q21
69:05B-022
69 :05D-006
Resistance
     68-69:04A-009
Resistance networks
     68-69:020-013
Resistivity
     68-69:02F-014
     68-69:05B-024
     68-69:076-021
Resources
     68-69:06B-005
Respiration
     68-69:020-029
Rock excavation
     68-69 :07B-015

Rock properties
     68-69:076-015
Rocks
                                      68-69:07B-015
Root development
     68-69:02I-005
     68-69:03F-026
Root systems
     68-69:02G-014
     68-69:02G-016
     68-69:021-019
     68-69:03F-026
     68-69:04A-010
                                                                Runoff forecasting
                                                                     68-69:02E-007
                                                                Safe yield
                                                                     68-69:02F-039
Saline soils
     68-69 :02F-009
     68-69:02F-025
     68-69 -.02G-032
     68-69:02G-039
     68-69 :02G-049
     68-69 :02G-061
     68-69 :02I-015
     68-59:02I-019
     68-69:02J-013
     68-69:030-001
     68-69:03C-004
     68-69:05B-007
     68-69:030-005
Retardants
     68-69:050-004
Retention
     68-69:02G-027
Return flow
     68-69:02G-069
     68-69:05B-002
     68-69:050-010
     68-69:056-027
     68-69:056-028
Root zone
     68-69:02F-025
     68-69:02G-024
     68-69 :02G-042
     68-69:02I-014
     68-69:02I-019
     68-69 :02I-023
     68-69:03F-020
Rotations
     68-69:02E-005
     68-69:056-017

      200
Saline water
     68-69:02F-001
     68-69:02F-008
     68-69:02F-025
     68-69:02F-044
     68-69:02G-017
     68-69:02G-024
     68-69 :03C-001
     68-69:02F-027
     68-69:05C-002
     68-69 :05C-003
     68-69 :05C-005
     68-69 :05D-010

-------
Saline water  (Cont.)
     68-69:05G-006
Saline water systems
     68-69:02G-031
     68-69:078-018
     68-69:05G-013
                     Sands
Salinity
     68-69
     68-69
     68-69:
     68-69:
     68-69:
     68-69:
     68-69
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69
     68-69
     68-69:
     68-69:
     68-69:
     68-69:
     68-69
02F-
02F-
02G-
02G-
02G-
02G-
02G-
02G-
02G-
021-
021-
021-
030-
030-
030-
030-
03F-
05B-
05B-
•008
•039
•024
•031
035
049
•051
•052
•069
•013
014
•015
•001
•003
•004
•005
010
007
•028
Salt balance
     68-69:02G-021
     68-69:03F-020
     68-69:030-005
     68-69 :06B-001
Salt tolerance
     68-69:02G-024
     68-69:021-019
     68-69:030-001
     68-69:030-004
     68-69:03F-020
Salts
     68-69,
     68-69
     68-69;
     68-69:
     68-69:
     68-69:
     68-69
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
02D-028
02F-044
02F-048
02G-021
02G-024
02G-039
02G-046
021-013
030-002
03F-020
050-002
05G-006
                          68-69:02F-009
                          68-69:02F-033
                          68-69:02F-038
                          68-69:02G-029
                          68-69:02J-012
                          68-69:05F-003
                          68-69:05F-004
Sanitary engineering
     68-69:05F-003
     68-69:05G-002
Saturated flow
     68-69:02F-016
     68-69:02F-017
     68-69:02F-030
     68-69:026-019
     68-69:02G-029
     68-69:020-037
     68-69:02G-046
     68-69:02G-064
     68-69:05B-014
     68-69 .-07B-004
     68-69:07B-012
     68-69:070-001
                     Saturated soils
                          68-69:02F-009
                          68-69 .-02F-048
                          68-69:02G-006
                          68-69:02G-068
                          68-69:02J-013
                          68-69:02K-002
                          68-69:02K-012
                          68-69:02K-018
                          68-69 .-05B-009
                          68-69:05G-003
                          68-69:07B-003
                 Saturation
                      68-69:020-001
                      68-69.-02F-022
                      68-69:02G-025
                      68-69:02J-012
                      68-69:02K-006
                      68-69:02K-019
                 Sawdust
                      68-69:02F-04e

                 Sea water
                      68-69:020-028
                                                Sediment distribution
                                                     68-69:02G-054
                                                Sediment transport
                                                     68-69:02G-054
                                                    Sediment yield
                                                         68-69:02J-015
Sediments
     68-69:02J-002
     68-69:05A-004
     68-69:056-005
Sedimentation
     68-69:02F-003
     68-69:02F-028
     68-69:04A-008
     68-69:050-008
Seeds
     68-69:021-002
     68-69:030-001
     68-69:030-004
     68-69:03F-008
     68-69:03F-010
                               Seepage
                                    68-69:
                                    68-69:
                                    68-69:
                                    68-69:
                                    68-69;
                                    68-69:
                                    68-69:
                                    68-69:
                                    68-69;
                                    68-69:
                                    68-69;
                                    68-69:
           02F-017
           02F-024
           02F-034
           02G-033
           02G-023
           02G-043
           02G-056
           02K-008
           03B-001
           03F-016
           04A-004
           07B-018
                               Seismic studies
                                    68-69:02F-011
                                                Seismology
                                                     68-69:078-021
                               Self-purification
                                    68-69:050-008
Samplers
     68-69:02J-003
Sampling
     68-69:02F-044
     68-69:02J-009
     68-69:05A-002
     68-69:078-002
     68-69:078-008
                                Seasonal
                                     68-69:020-021
                     Sediment
                          68-69:02J-003
                          68-69:030-001
                          68-69:058-015
                          68-69:05G-009
                          68-69:056-021
                          68-69:07B-008
                                                Semiarid climates
                                                     68-69:020-015
                                                     68-69:02F-009
                                                     68-69:021-017
                                                     68-69:03F-006
                                                     68-69:050-004
                                                Sewage
                                                      68-69:050-008
                                       201

-------
 Sewage effluent
      68-69:05D-007
 Sewage treatment
      68-69:05B-Oll
      68-69:050-005
      68-69:05E-002
 Scaling
      68-69:08A-001
 Shafts (Excavations)
      68-69:02F-028
 Shape
      68-69:02E-004
 Sheet erosion
      68-69:02J-007
 Silting
      68-69:02F-006
 Silts
      68-69 :02J-003
      68-69:02J-012
Simulated  rainfall
      68-69:02F-007
      68-69:02J-016
Simulation
     68-69:06B-006
Simulation analysis
     68-69 :02D-013
     68-69:02E-009
     68-69:02F-020
     68-69:02F-045
Sinks
     68-69:05G-009
Siphons
     68-69:03F-022
Slope protection
     68-69:02J-004

Slope stability
     68-69:02J-016
Slopes
     68-69:02I-017
     68-69:02J-007
     68-69:02J-012
     68-69:02E-008
     68-69:02J-005
 Slopes  (Cont.)
      68-69 :02J-006
      68-69:02J-008
      68-69:02J-011
      68-69 -.03F-001
 Sludge
      68-69:05E-002
      68-69:05E-003

 Sludge  digestion
      68-69:05E-003

 Sludge  disposal
      68-69 :05E-003
 Small watersheds
     68-69:02F-011

 Social aspects
     68-69:02J-014
     68-69:04A-008
     68-69:06B-002
Social values
     68-69 :03D-001
     68-69:050-011
Sodium
     68-69:02F-007
     68-69 :02G-017
     68-69:02G-024
     68-69:02G-069
     68-69:02K-019
     68-69 :03C-002
     68-69 :03C-003
     68-69:05A-001
Sodium compounds
     68-69:02K-014
Soil
     68-69:02G-033
     68-69:02G-062
     68-69:02K-010
     68-69:05A-009
Soil aggregates
     68-69:02G-027
     68-69:02G-041
     68-69:02J-012
     68-69:02G-051

Soil amendments
     68-69:02G-041

Soil analysis
     68-69 :02G-004
     68-69:03F-012
     68-69 -.05A-001
Soil chemical proper-
  ties
     68-69:02F-046
     68-69:02G-019
     68-69-.02G-034
     68-69:02G-041
     68-69 :02G-049
     68-69:02G-052
     68-69:02K-010
     68-69:050-004
     68-69:02K-011

Soil chemistry
     68-69:02G-017
     68-69 :02G-021
     68-69:02G-034
     68-69:02G-039
     68-69:02K-002
     68-69--02K-009
     68-69:076-013
Soil classification
     68-69:02G-027
     68-69:040-001
Soil compaction
     68-69:02F-022
     68-69:02J-011
Soil conservation
     68-69:02E-004
     68-69:02G-048
     68-69:02G-059
     68-69:02J-004
     68-69:02J-007
     68-69:02J-012
     68-69:02J-014
     68-69:05B-021
     68-69 :05B-006
     68-69:06B-005
                               Soil density
                                    68-69:02G-062
                                    68-69:07B-007
                                                                Soil disposal fields
                                                                     68-69:050-004
                                                                Soil environment
                                                                     68-69:02I-013
Soil erosion
     68-69:02G-008
     68-69:02G-013
     68-69:02G-015
     68-69:02G-059
     68-69:02J-004
     68-69:02J-005
     68-69:02J-006
     68-69:02J-007
     68-69:02J-009
     68-69:02J-011
     68-69:02J-012
     68-69:02J-014
     68-69:02J-016
                                      202

-------
Soil erosion  (Cont.)
     68-69:04A-010
     68-69:056-006
Soil fertility
     68-69:05E-002
Soil horizons
     68-69:020-004
     68-69:02G-027
     68-69:078-006
Soil investigations
     68-69:07B-013
Soil management
     68-69:020-041
     68-69:020-048
     68-69:030-005
     68-69:05A-007
Soil mechanics
     68-69:020-027
     68-69:020-059
     68-69:020-061
     68-69:02J-005
     68-69:02J-006
     68-69:033-001
Soil microbiology
     68-69:05E-002
     68-69:05F-004
Soil moisture
     68-69:020-005
     68-69:020-011
     68-69:020-012
     68-69:020-017
     68-69:020-020
     68-69:02E-007
     68-69:020-006
     68-69:020-009
     68-69:020-011
     68-69:020-012
     68-69:020-013
     68-69:020-015
     68-69:020-016
     68-69:020-025
     68-69:020-018
     68-69:020-020
     68-69:020-026
     68-69:020-028
     68-69:020-048
     68-69:020-051
     68-69:020-064
     68-69:021-002
     68-69:058-009
     68-69:07B-007
     68-69:078-013
     68-69:020-040
     68-69:020-045
     68-69:020-042
Soil moisture
     68-69:020
     68-69:020
     68-69:020
     68-69:02G
     68-69:021
     68-69:021
     68-69:021
     68-69:021
     68-69:02K
     68-69:03F
     68-69:03F
     68-69:03F
     68-69:05B
     68-69:07B
     68-69:076
     68-69:076
     68-69:07B
     68-69:07B
 (Cont.)
-050
-057
-065
-071
-006
-012
-016
-021
-Oil
-015
-021
-025
-018
-009
-010
-Oil
.-020
-022
Soil moisture meters
     68-69:073-007
     68-69:078-009
     68-69:078-010
     68-69:078-011
     68-69:078-014
     68-69:078-015
     68-69:078-020
     68-69:078-022
                                Soil moisture movement
                                     68-69:02G-036
Soil physical properties
     68-69:02G-004
     68-69:020-013
     68-69:020-041
     68-69:020-048
     68-69:020-052
     68-69:02G-059
     68-69:02G-064
     68-69:02J~012
     68-69:02K-011
     68-69 :05D-004
Soil physics
     68-69:02G-006
     68-69:020-051
     68-69:078-013
     68-69:078-017
Soil profiles
     68-69:02F-050
     68-69:02G-022
     68-69:020-032
     68-69:020-044
     68-69:030-004
Soil properties
     68-69:02K-015
     68-69:038-001
Soil science
     68-69:020-022
     68-69:020-013
     68-69:020-020
     68-69:02J-009
                                                               Soil sealants
                                                                    68-69:038-001
Soil stability
     68-69:02J-012

Soil stabilization
     68-69:02G-049

Soil strength
     68-69:020-041
     68-69:02J-012
                 Soil structure
                      68-69:020-008
                      68-69.-02G-041
                      68-69:02J-012
                      68-69:02G-025
                      68-69:02G-027

                 Soil surfaces
                      68-69:02G-008
                      68-69:026-032
                      68-69:020-068
                      68-69:05C-004
                      68-69:02G 015
                      68-69:020-039
                      68-69:020-063
                                                               Soil surveys
                                                                    68-69:058-007
                 Soil temperature
                      68-69:020-003
                      68-69:026-032
                      68-69:020-048
                      68-69:020-052
                      68-69:021-021
                      68-69:03F-006
                 Soil texture
                      68-69 :02G-046
                      68-69:020-015
                      68-69:020-041
                      68-69:020-044
                      68-69:020-059
                      68-69:02J-012
                      68-69 :05B-007
                 Soil treatment
                      68-69:020-015
                      68-69:020-041
                      68-69:050-006
                                      203

-------
 Soil  types
      68-69:02E-008
      68->59:02F-015
      68-69:02G-044
      68-69 :07B-006
      68-69:078-015
Soil water
     68-69
     62-69
     68-69
     68-69
     68-69
     63-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     63-69
     68-69
     68-69
     63-69
     68-69
     63-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
 020
 02D
 02E
 02G
 02G
 02G
 02G
 02G
 o: G-
 02G
 021
 021
 021
 02K'
 02K'
 03F'
 04A'
 05A
 05B'
 05B'
 05C-
 05G-
 07B-
 07B-
 07B-
 07B-
 07B-
 07B-
 073-
 07B-
 073-
-015
-026
-00.8
-019
-024
-028
-032
-063
-068
-072
-007
-009
-013
-Oil
-018
-024
-002
-007
-010
-018
-004
-003
-006
-007
-009
-010
-Oil
-012
-013
-014
-019
Soil-water infiltration
     68-69:020-007
Soil water
     68-69
     68-69
     63-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     68-69
     63-69
     68-69
     68-69
     68-69
     68-69
     68-69
     63-69
     68-69
     68-6S
     68-69
movement
02A-001
02D-016
02E-009
02F-019
02F-024
02F-03C
02F-033
02G-003
02G-014
02G-016
02G-019
02G-022
02G-029
02G-030
02G-031
02G-032
02G-035
02G-037
02G-038
02G-040
02G-041
02G-042
02G-043
02G-044
Soil vater movement  (Cent.)
     68-69 02G-046
     68-69 02G-047
     68-69 02G-04S
     68-69 02G-049
     68-69 02G-051
     53-69 02G-055
     68-69 02G-055
     68-69 02G-060
     68-69 03F-011
     63-69 05E-004
     63-69 05G-003
     68-69 07B-013
     53-59 07E-OI9
Soils
es-->s9
63-59
68-6S
63-69
68-69
68-69
68-69
68-69
68-69
68-69
68-69
68-69
68-69
68-69
68-69
68-69
68-69
68-69
68-69
68-59
68-69
53-69
66-69
53-69
68-69
68-69
68-69
68-69
66-69
68-69
68-69
68-69
68-69
68-59
53-69
53-69
68-69
68-59
58-69
68-69
63-59
0 2 D - G 0 4
020-015
020-020
020-026
02F-025
02G-003
02G-016
02G-018
02G-026
021-006
021-007
021-011
021-013
021-014
021-015
021-017
021-018
021-019
03F-021
021-022
021-023
03C-001
03F-014
03F-023
03F-026
C3F-027
03F-030
07B-013
07B-023
02F-007
02F-022
02F-024
02G-013
02G-020
02G-054
02K-OOS
C3B-001
04A-005
05B-018
05E-002
05E-004
                  Solar radiation
                       65-69
                       68-69
                             02D-00;
                                                     Solar radiation  (Cont.)
                                                          68-69:03F-006
                                                          68-69:07A-001
                                                     Solid wastes
                                                          68-69:050-001
Solubility
     68-69 -02K-010
Solutes
     68-69:02G-C38
     68-69 :02G-046
     68-69 :02I-013
     68-69 :C53-003
     68-69:05G-010
                                Sorghum
                                     68-69:020-015
                                     63-69:020-017
                                     68-69 :02D-026
                                     68-69 :02I-003
                                     68-69:02I-017
                                Sorption
                                     63-69:02G-051
                                     68-69 :02K-010
                                South  Dakota
                                    63-69:02F-042
                                    68-69:02E-004

                                South  Dakota  (Minnesota)
                                    68-69 :03F-015

                                Soybeans
                                    63-69:03F-023
                                                                Specific retention
                                                                     68-69 -.04A-002
                                                  Specific  yield
                                                       68-69:02F-012
                                                       63-69 :02G-032
                                                       68-69:C4A-002

-------
Sprinkler irrigation
     68-69:02A-002
     68-69:020-014
     68-69:02E-008
     68-69:02G-025
     68-69:03F-004
     68-69:03F-028
     68-69:04A-003
     68-69:05E-004
Stabilization
     68-69:05E-003
Standards
     68-69:050-005
State governments
     68-69:06E-002
Statistical methods
     68-69:02G-018
     68-69:02J-011
     68-69:066-001
Statistics
     68-69 :02I-011
     68-69:03F-012

Steady flow
     68-69:02F-017

Stokes law
     68-69:04A-011
Streamflow
     68-69:02E-007
     68-69:02F-026
     68-69:03F-003
     68-69:05B-020
     68-69:056-010
     68-69:050-012
     68-69:073-018
Streams
     68-69:02F-011
     68-69:02F-045
Strip aquifer
     68-69:02F-035
Strip cropping
     68-69 :02J-004
Strontium
     68-69 :05B-017
                                Subarctic
                                     68-69:02K-017
Subhumid climates
     68-69:02K-014
Sublimation
     68-69 :02D-028
Subsurface irrigation
     68-69:02F-010
     68-69:020-040
Subsurface mappinq
     68-69:02F-Oil
                                                               Subsurface runoff
                                                                    68-69:02E-009
                                                               Sudangrass
                                                                    68-69:02G-027
                                                               Sugar
                                                                    63-69:05F-002
                                                               Sugar cane
                                                                    68-69:06B-003
                               Sulfates
                                    68-69:02G-069
                                    68-69 :02K-002
                                    68-69:02K-012
Sulfides
     68-69:02K-002
     68-69:02K-012
Sulfur bacteria
     68-69:02K-012
Stomata
     68-69:020-019
     68-69:020-025
     68-69:02I-020
     68-69:03F-011
                                Submergence
                                     68-69:02F-037
Subsoil
     68-69:02G-040
                               Sulfur compounds
                                    68-69:02K-002
                               Summer
                                    68-69:05C-004
Storage
     68-69:03F-019
Storage capacity
     68-69:02E-004
     68-69:02G-048
Storage coefficient
     68-69:02F-032
     68-69:02F-041
Storm runoff
     68-69:02J-010
Strain gauges
     68-69 .-02G-028
Subsidence
     68-69:02F-037
Subsurface drainage
     68-69--02F-006
     68-69:02F-009
     68-69:02F-016
     68-69:020-005
     68-69:02G-012
     68-69:020-023
     68-69:05E-001
     68-69:050-013

Subsurface drains
     68-69:06A-001
Subsurface investigation
     68-69 :07B-021
Supplemental irrigation
     68-69 :03F-013
     68-69:03F-030
     68-69:04A-007
                                                               Surface drainage
                                                                    68-69:020-012
Surface-groundwater
  relationships
     68-69:02E-009
     68-69 :02F-013
     68-69 :02F-026
     68-69 :02F-029
     68-69 :02F-045
     68-69 :02G-043
     68-69:05B-002
                                      205

-------
 Surface irrigation
      68-69:02E-002
      68-69:03F-001
      68-69:03F-002
      68-69:Q3F-019
 Surface  runoff
      68-69:02E-003
      68-69:02E-004
      68-69:02E-006
      68-69-.02G-013
      68-69:02G-059
      68-69:030-002
      68-69:058-015
 Surface waters
      68-69-.02F-036
 Surveys
      68-69:02F-011
      68-69:02F-012
      68-69:02F-014
Svnthetic hydrology
      68-69:02F-024
      68-69:02F-020
Tagging
       3-69:02J-009
Taxes
     68-69:066-004
Temperature
     68-69:020-001
     68-69:020-024
     68-69:02G-016
     68-69:020-050
     68-69:02G-051
     68-69:07A-001
Temperature control
     68-69:020-014
     68-69:02F-039
     68-69:02G-050
Tension
     68-69:02G-028
     68-69:073-019
 Terraces
      68-69:02J-010
      68-69:06B-005
 Terracing
      68-69-.02E-004
      68-69:02j-004
      68-69:02J-008
Tertiary  treatment
      68-69:050-002
      68-69:05D-005
                                 Texas
      68-69:02F-012
      68-69:02F-033
      68-69:02G-017
      68-69:02G-026
      68-69:02J-008
      68-69:030-002
      68-69:050-003
      68-69:078-018
Thermal water
     68-69:02F-044
Theis equation
     68-69:02E-001
     68-69:02F-031
     68-69:07C-001
Theoretical analysis
     68-69:02G-039
     68-69:02K-009
Thermodynamic behavior
     68-69:02G-060
Thermodynamic s
     68-69:02G-060
     68-69:02K-011
     68-69:078-023
Thermocline
     68-69:02G-032
Thermometers
     68-69:07B-017
Thermal conductivity
     68-69:02G-050
Thermal pollution
     68-69:02F-039
     68-69:07A-001
Thin-layer chromato-
  graphy
     68-69:05A-005
Tile drainage
     68-69:02F-006
     68-69:02F-015
     68-69:02F-046
     68-69:058-018
     68-69:05G-003
     68-69:02F-009
Tile drains
     68-69:02G-021
     68-69 -.04A-OLL
     68-69:02F-015
Tiles
     68-69:02F-003
     68-69:02F-009
     68-69:02F-015
     68-69--02F-033
     68-69:05G-006
Tillage
     68-69:03F-024
                                                               Time
                                    68-69:02G-013
                               Time lag
                                    68-69:07B-003
Timing
     68-69:02G-026
     68-69:03F-030
     68-69.-03F-013
     68-69:04A-006
Tobacco
     68-69:02K-004
     68-69:05G-007
Tensiometers
     68-69:02D-009
     68-69:02G-027
     68-69:02G-028
     68-69:02G-038
     68-69:03F-001
     68-69-.03F-03Q
     68-69:07B-019
Thermoperiodism
     68-69:02D-010
Thiems eauation
     68-69.-07C-001
Tomatoes
     68-69:02I-023
     68-69:03F-026
     68-69:05D-006
                               Topography
                                    68-69:02D-002
                                    68-69:02J-007
                                    68-69:05B-007
                                      206

-------
Topsoil
     68-69:02G-040
                     Tubes
                                     68-69:02F-010
                                                    Value
                                                         68-69:03F-012
Toxicity
     68-69:058-011
Trace elements
     68-69:02F-044
     68-69:05E-003
Tracers
     68-69
     68-69:
     68-69
     68-69
     68-69.
     68-69:
     68-69;
     68-69;
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
02F-023
02F-029
02F-034
02F-038
02G-054
02G-055
02G-056
02G-067
02J-007
02J-009
04A-004
04A-010
05B-023
07B-018
                     Turbidity
                          68-69:020-010
                          68-69:02F-028
                          68-69:02F-039
                          68-69:05F-004
                                Turbulence
                                     68-69:021-020
Turgidity
     68-69:02I-013
     68-69:021-015
     68-69:078-005
Turnout gates
     68-69:03F-002
Turnouts
     68-69:04A-006
Vapor pressure
     68-69:020-001
     68-69:03F-006

Variability
     68-69:020-020
     68-69:02G-016

Vegetation effects
     68-69:020-012
     68-69:02G-003
     68-69:02G-018
     68-69:021-013
Vegetation establish-
  ment
     68-69:021-021
     68-69:02J-014
Velocity
     68-69:02F-023
Tracking techniques
     68-69:02G-056
     68-69:058-023
     68-69:078-018
Transients
     68-69:02E-001
Translocation
     68-69:02G-016
     68-69.-02G-032
Transmissivity
     68-69:02F-014
     68-69:02F-032
     68-69:02F-040
Transpiration
     68-69:020-005
     68-69:020-008
     68-69:020-009
     68-69:020-028
     68-69:021-014
Transpiration control
     68-69:020-019
     68-69:020-025
     68-69:03F-011
                     Underseepage
                          68-69:02F-034
                     Uniformity coefficient
                          68-69:02A-002
                          68-69:04A-003
                     Unsteady flow
                          68-69:02E-001
                          68-69:02F-021
                          68-69:02F-030
                          68-69:02F-031
                          68-69:02F-041
                          68-69:02G-023
                          68-69:03F-019
                     Unsaturated flow
                          68-69:02F-016
                          68-69:02F-020
                          68-69:02F-030
                          68-69:02F-043
                          68-69:020-006
                          68-69:02G-022
                          68-69:02G-035
                          68-69:02G-037
                          68-69:02G-042
                          68-69:02G-045
                          68-69:02G-056
                          68-69:02G-060
                          68-69:020-063
                          68-69:078-013
                          68-69:07C-001
                               Volume
                                    68-69:02J-003
                                    68-69:03F-003
                                                               Waste
                                                                    68-69 :05B-021
                               Waste disposal
                                    68-69:050-003
                                    68-69:050-004
                               Waste water
                                    68-69:02K-007
                                    68-69:050-001
                               Waste water (Pollution)
                                    68-69:02F-047
                                    68-69:058-026
                                    68-69:050-003
                                    68-69:050-004
                               Waste water disposal
                                    68-69:02F-039
                                    68-69:050-003
                                    68-69:05E-004
                               Waste water irrigation
                                    68-69 :05E-005
Trap efficiency
     68-69 :02J-015

Tritium
     68-69:02F-029
     68-69:02J-009
     68-69:078-018
                     Ureas
                          68-69:02E-003
                          68-69:02K-004
                          68-69:02K-005
                               Waste water treatment
                                    68-69.-02F-039
                                    68-69:050-005
                                    68-69:050-006
                                    68-69:050-008
                                    68-69:050-009
                                    68-69:05E-005
                                       207

-------
 Wastes
      68-69:02F-050
      68-69:05A-004
 Hater balance
      68-69:020-015
      63-69-.02D-016
      68-69:020-027
      68-69:02E-007
      68-69.-C2F-013
      68-69:020-021
      68-69:020-023
      68-69:068-003
Water  chemistry
     68-69:02F-044
     68-69:020-038
     68-69:020-061
     68-69:02K-011
     68-69:02K-012
     68-69:030-002
     68-69:04A-005
     68-69:05B-003
     68-69:05D-004
     68-69:050-010
     68-69:050-012
Water conservation
     68-69:02D-006
     68-69:020-008
     68-69:020-019
     68-69:020-025
     68-69:02E-004
     68-69:030-001
     68-69:03F-017
     68-69:03F-021
     68-69:03F-025
     68-69:05B-006
     68-69:06B-005
     68-69:06E-002
Water consumption  (Plants)
     68-69:03F-014
Water control
     68-69:02J-004
     68-69-.02J-014
     68-69:04A-006
Water delivery
     68-69:03F-005
     68-69:03F-007
 Water  demand
      68-69 :02F-045
      68-69 :05D-001
      68-69:05D-003
      68-69 :06B-001
      68-69 :06B-003
      68-69:021-016
Water distribution
   (Applied)
     68-69:02A-002
     68-69 :02F-010
     68-69 :03F-002
     68-69:03F-004
     68-69:03F-005
     68-69:03F-013
     68-69:03F-022
     68-69:04A-003
     68-69 :04A-006
Water harvesting
     68-69:021-017
Water holes
     68-69 :02K-008
Water law
     68-69 :06E-003
     68-69 -.06E-004
Water level fluctuations
     68-69:02F-012
     68-69:02F-013
     68-69:02F-014
     68-69 :02F-016
     68-69:02F-030
     68-69:02F-031
     68-69:02I-016
     68-69 :07C-001
Water levels
     68-69 :02F-012
     68-69:02F-014
     68-69 :02F-017
     68-69:02F-037
Water loss
     68-69
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69:
     68-69;
     68-69:
     68-69:
     68-69:
     68-69:
02D-001
02D-015
020-021
020-009
020-048
03F-003
03F-006
03F-011
03F-014
03F-016
05C-004
07B-006
                                Water management
                                     68-69:02D-017
                                     68-69:021-004
                    Water management
                       (Applied)
                         68-69:02A-001
                         68-69:020-019
                         68-69:020-025
                         68-69:02F-011
                         68-69:02F-036
                         68-69:02F-045
                         68-69:02F-047
                         68-69 :02J-016
                         68-69:03A-001
                         68-69:030-001
                         68-69:03F-003
                         68-69 :03F-014
                         68-69:04A-011
                         68-69:05D-003
                         68-69:06E-003
                         68-69:056-027
                         68-69:050-013
                    Water-plant relation-
                      ships
                         68-69:020-027
                               Water permits
                                    68-69:06E-002
                    Water pollution
                         68-69:02F-050
                         68-69:02J-003
                         68-69:03F-029
                         68-69:05A-004
                         68-69:05A-006
                         68-69:056-008
                         68-69:05B-011
                         68-69:058-014
                         68-69:058-015
                         68-69:058-020
                         68-69:058-021
                         68-69:05B-024
                         68-69:058-026
                         68-69:05C-003
                         68-69:050-005
                         68-69:05F-003
                         68-69:050-004
                         68-69:050-006
                         68-69:050-011
                         68-69:068-002
                         68-69:06B-006
Water pollution control
     68-69-.03A-001
     68-69:050-003
     68-69:050-011
     68-69:06E-002
     68-69:058-027

Water pollution effects
     68-69:053-004
     68-69:058-028

Water oollution sources
     68-69:02E-005
     68-69:02J-003
     68-69:056-004
     68-69:05B-005
     68-69:058-011
     68-69:058-014
     68-69:058-018
     68-69:05B-027
                                      208

-------
Water pollution  sources  (Cont
     68-69:058-020
     68-69 :05B-022
     68-69:05E-022
     68-69:058-026
     68-69:050001
     6S-69:05C-003
     68-69:050-005
     68-69:050-003
     68-69:05G-006
     68-69:07B-018
     68-69:058-028

Water pollution  treatment
     68-69:053-011
Water pressure
     68-69:02G-040
Water properties
     68-69:02G-044
Water ourification
     68-69:04A-005
     68-69:05F-004
Water quality
     68-69:02F-039
     68-69:02F-042
     68-69:02F-044
     68-69:020-019
     68-69:02G-049
     68-69:020-069
     68-69:02K-011
     68-69 :C3C-002
     68-69:03F-029
     68-69:04A-005
     68-69:04A-008
     68-69.-05A-002
     68-69:058-018
     68-69:C5B-024
     68-69:05B-026
     68-69:05C-001
     68-69:05C-005
     68-69:05D-002
     68-69:05D-005
     68-69:G5E-005
     68-69 :05G-002
     68-69:05G-003
     6S-69:05G-010
     68-69:050-012
     68-69:06B-002
     68-69:056-027

Water quality control
     68-69:05G-005
     68-69 :06B-001
     68-69:058-028

Water requirements
     68-69 :02D-021
     68-69 :02D-022
     68-69:021-007
     68-69:03F-020
     68-69:03F-030
Water resource development
     68-69:05B-006
Water resources
     68-69 :C2F-035
     68-69 :02J-003
     68-69 :03F-C16
     68-69:05G-005
Water resources develooment
     68-69 :C2r-C36
     68-69 :06E-003
Water reuse
     68-69:02E-002
     68-69:02F-029
     68-69 :02F-047
     68-69 :03F-001
     68-69 :03F-005
     68-69:05B-014
     58-69 :05D-001
     68-69 :05D-003
     68-69 :05C-004
     68-69 :05D-005
     68-69:05B-028

Water rights
     68-69 :02F-045
     68-69:03F-007
     68-69 :06E-003
     68-69:05E-028
Water shortage
     68-69 :02D-017
 Water supply (Cont.)
      68-69:050-005
      68-69:050-002
      68-69:068-001
      68-69:06B-002
Water sports
      68-69.-05C-005
•7ater storage
     68-69 :02E-004
     68-69 :02E-009
     68-69 :02^-011
     68-69 :02F-026
     68-69 :02F-C4Q
     68-69 :02G-OC9
     68-69 :02G-010
     68-69:02G-015
     68-69:02G-013
     68-69:02G-027
     68-69 :03C-002
     68-69 :04A-002
     68-69:05B-026
     68-69.-05C-004
Water structure
     68-69 .-02G-055
Water supply
     68-69 :02D-017
     68-69 :02F-C47
     68-69:C3F-013
     68-69:03F-007
     68-69:03F-016
Water table
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
      68-69
02F
02F
02F
02F
02F'
02F'
02F'
02F'
02F'
02F'
02F'
02G
02G
020
02 j
02K
021
04A
-008
-009
-Oil
 •013
 •014
 •017
 019
 •032
 •033
 •039
 •043
 •OC5
 •020
 •032
 •013
 •020
 •016
 •010
Water temperature
      68-69:02D-010
      68-69:02F-044
      68-69 :02G-060
Water transfer
      68-69-020-051

Water treatment
      68-69:05F-004

Water users
      68-69 :03A-OC1

Water utilization
      68-69 :02D-008
      68-69 :02D-017
      68-69 :02E-002
      68-69:020-026
      68-69 :02I-016
      68-69:021-017
      68-69 :02I-019
      68-69 :03F-014
      68-69:03F-020
      68-69;03F-016
      68-69:050-001

Water vapor
      68-69 :02D-011
      68-69:02G-051
      68-69:020-060
Water wells
      68-69:05B-023
      68-69:058-026
                                       209

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 Water yield
      68-69:020-025
      68-69:02F-014
      68-69:021-017
      68-69:02J-010
      68-69:06B-003
      68-69:07B-016
 Water  yield  improvement
     68-69:02D-019
     68-69:02E-006
     68-69:021-017
     68-69:03F-011
Wetlands
      68-69:04A-008
Wettability
      68-69:078-011
Wetting
      68-69:020-029
      68-69:02G-030
      68-69 :03F-003
      68-69:07B-011
                               Winds
     68-69:020-013
     68-69:02D-022
     68-69:021-020
     68-69:04A-003
Winter
     68-69:02G-026
     68-69:02G-032
Wisconsin
     68-69:05B-003
Watershed  hydrology
      68-69:07B-012
Wetting and drying tests
     68-69:02G-020
Withdrawal
     68-69:02F-041
                                 Wheat
Watershed management
      68-69:020-019
      68-69:020-025
      68-69:02E-006

Watersheds
      68-69:04D-001
     68-69:020-008
     68-69:020-015
     68-69:020-017
     68-69:020-026
     68-69:021-003
     68-69:02G-026
                                                               Worms
     68-69:05F-003
Wyoming
     68-69:020-023
Watersheds  (Basins)
      68-69:02E-006
      68-69:02J-003
      68-69:030-002
Wheat moisture avail-
  ability
     68-69:03F-024
Xylem
     68-69:021-013
     68-69:021-014
     68-69:02I-015
Weather
     68-69:020-002
     68-69:04A-007

Weathering
     68-69:02G-015
     63-69:05B-003

Weed control
     68-69:02F-006
     68-69:05A-006
Wheatgrasses
     68-69:020-023
     68-69:021-017
     63-69:02K-017
Wildlife
     68-69 :05C-005

Wilting
     68-69:07B-005
Weirs
     68-69:02J-003
Wilting point
     68-69:02G-027
     68-69:02G-004
Well casings
     68-69:02F-002
Well filter
     68-69:02F-002

Well screens
     68-69:02F-002
Wind erosion
     68-69:02J-005
     68-69:02J-006
Wind pressure
     68-69:03F-028
Wellpoints
     68-69:02F-002
Wind speed
     68-69:020-022
Wells
     68-69:02F-002
     68-69.-G2F-005
     68-69:02F-034
     68-69:02F-035
     68-69:02F-044
     68-69:02F-050
     68-69:076-015
Wind velocity
     68-69:02A-002
     68-69:020-002
     68-69:02D-024
     68-69:03F-004
     68-69:03F-006
     68-69:03F-028
     68-69:04A-003
                                      210

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                        SECTION XXXIII


                       ACKNOWLEDGMENTS
The excellent cooperation of the reading room staff  at  the
Engineering Research Center and the library  staff at Colorado
State University has been very important in  accomplishing
the work reported herein.

Besides the authors, Mr. James E. Ayars, Graduate Research
Assistant in the Agricultural Engineering Department, has
assisted in preparing abstracts.

The efforts of Miss Kevin Feigen in preparing the necessary
forms which are forwarded to the Water Resources Scientific
Information Exchange, along with the typing  of  this  report,
are sincerely appreciated.

The scope of this literature abstracing effort  has been
delineated jointly by the senior author and  the Project
Officer, Dr. James P. Law, Jr., Program Element Director,
Irrigation Return Flow Research Program, Agricultural Wastes
Section, Treatment and Control Research, Robert S. Kerr
Water Research Center, Environmental Protection Agency,  Ada,
Oklahoma.  The efforts of the Project Officer in meeting
with project personnel numerous times to review the  abstract-
ing process have been very helpful and much  appreciated.
                              211    *U.S. GOVERNMENT PRINTING OFFICE:1973
                                                       514-149/98 1-3

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  SELECTED WATER
  RESOURCES ABSTRACTS
  INPUT TRANSACTION FORM
1. Report No.
  4. Title     SELECTED  IRRIGATION RETURN FLOW
            QUALITY ABSTRACTS 1968-1969
  7. Author(s)  Qaylord V.  Skogerboe, Venus T.  Sahni,
            and Wynn  R.  Walker
  9. Organization
            Agricultural Engineering Department
            Colorado  State University
            Fort Collins,  Colorado 80521
 3. Accession No.

 w

 5. Report Date
 6.
 8. Performing Organization
   Report No.
10. Project No.
EPA Program  13030FVN
                 11. Contract/Grant No.
                                                        13. Type of Report and
                                                           Period Covered
    Sponsoring Organization

    Supplementary Notes
  :f. 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 re-
   turn flow quality  control.

   This first annual  issue of SELECTED IRRIGATION  RETURN FLOW QUALITY AB-
   STRACTS covers publications printed in 1968  and 1969.  This report was  j
   submitted in fulfillment of Project Number 13030FVN, Contract  14-12-01, |
   under the sponsorship of the Office of Research and Monitoring, Environ-j
   mental Protection  Agency.                                                 !
   a. Descriptors  Fertilizers,  Irrigated land,  Irrigated systems, Irrigation
   water, Nitrates,  Phosphates, Return flow,  Salinity, Water pollution ef-
   fects, Water pollution  sources, water quality  control.
  17b. Identifiers
  I7c. COWRR Field A Group
                      05G
18. Availability
Abstractor Gaylord V.
19. Security Class.
(Report)
20. Security Class.
(Page)
21. No. of
Pages
22. Price
Send To :
WATER RESOURCES SCI ENTIFiC INFORMATION CENTER
U S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D C. 20240
Skogerboe 1 /jutitutioa Colorado State University
WRSIC 502 (REV JUNE 1971)
                                                                     GPO 913.26 t

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