EPA-66Q/2-75-005
APRIL 1975
Environmental Protection Technology Series
Management Practices Affecting
Quality and Quantity of Irrigation
Return Flow
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Corvallis, Oregon 97330
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development,
U.S. Environmental Protection Agency, have been grouped into
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 STUDIES 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.
This report has been reviewed by the Office of Research and
Development, EPA, and approved for publication. Approval does
not signify that the contents necessarily reflect the views and
policies of the Environmental Protection Agency, nor does mention
of trade names or commercial products constitute endorsement or
recommendation for use.
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EPA-660/2-75-005
APRIL 1975
MANAGEMENT PRACTICES AFFECTING QUALITY
AND QUANTITY OF IRRIGATION RETURN FLOW
By
Larry G. King
Department of Agricultural and
Irrigation Engineering
and
R. John Hanks
Department of Soil Science and
Biometeorology
Utah State University
Logan, Utah 84322
Grant No. S801040
Program Element 1BB039
ROAP 21AYS Task 005
Project Officer
James P. Law, Jr.
Robert S. Kerr Environmental Research Laboratory
National Environmental Research Center
P. 0. Box 1198
Ada, Oklahoma 74820
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CORVALLIS, OREGON 97330
For Sale by the National Technical Information Service
U.S. Department of Commerce, Springfield, VA 22151
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ABSTRACT
Field and laboratory research was conducted to determine the effects of
irrigation management and fertilizer use upon the quality and quantity
of irrigation return flow. The total seasonal discharge of salts from
the tile drainage system was directly related to the quantity of water
discharged, because the solute concentration of the ground water was
essentially constant over time. Under such conditions, reduction of
salt content of return flow is accomplished by reduced drain discharge.
Irrigation management for salinity control must be practiced on a
major part of a particular hydrologic unit so that benefits are not
negated by practices in adjoining areas.
Field studies and computer models showed that salts may be stored in
the zone above the water table over periods of several years without
adversely affecting crop yields on soils with high "buffering"
capacity as encountered in this study. However, over the long term,
salt balance must be obtained.
Appreciable amounts of nitrate moved into drainage water at depths of
at least 106 cm from applications of commercial fertilizer and dairy
manure to ground surface. Submergence of tile drains in the field
reduced nitrate concentrations in the effluent, especially under heavy
manure applications.
This report was submitted in fulfillment of Grant No. S801040 by Utah
State University under the partial sponsorship of the Environmental
°rotection Agency. Work was completed as of November 30, 1973.
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CONTENTS
Page
Abstract i
List of Figures ill
List of Tables v
Acknowledgments ix
Sections
I Conclusions 1
II Recommendations 3
III Introduction 5
IV Methods 9
V Results and Discussion 29
VI References 94
VII Publications 96
VIII Appendices 97
ii
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FIGURES
No. Page
1 Map of study area on the Hullinger farm near Vernal, Utah. 10
2 Schematic diagram of 4-probe conductivity apparatus with
associated switching arrangement. 14
3 Manure plot layout on Hullinger farm. 26
4 Cumulative evapotranspiration measured by lysimeters compared
with potential evaporation computed with Penman's equation
for 1972. 30
5 Comparison of electrical conductivity measured from samples
taken from ceramic samplers with 4-probe corrected values. 41
6 Soil solution electrical conductivity (mmhos/cm) as measured
by the 4-probe horizontal probe before and after water
application - field trial 1. 42
7 Soil solution electrical conductivity (mmhos/cm) as measured
by the 4-probe horizontal probe before and after water
application - field trial 2. 43
8 Relative dissolved salt for various water-soil ratios -
laboratory trial 1. 52
9 Ratio of EC of irrigation water to EC of effluent as a func-
tion of pore volume of the effluent - laboratory trial 1. 54
10 Comparison of curves for effluent EC and 4-probe EC as
related to pore volume - laboratory trial 2. 55
11 Comparison of effluent EC with 4-probe EC of bottom column
section - laboratory trial 2. 56
12 Comparison of cumulative evapotranspiration vs. time for
two water application amounts and two initial soil solution
concentrations. 60
13 Salt concentration profiles at the end of the season for
three water application amounts for a deep rooted crop and
a shallow rooted crop. 64
14 Computations made of relative transpiration, T/Tp, and
average salt concentration as influenced by time where
the water application amount was about 22 cm deep for the
deep rooted crop. 65
iii
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FIGURES (Continued)
No,
15 Nitrate-N in the soil samples from plots with varying amounts
of Ca(NO_) fertilizer spread on the soil surface. Sampled
June 28, 1972 shortly after the fertilizer was added. 68
16 Nitrate-N in soil samples and in alfalfa and corn leaves as
related to Ca(NO ) fertilizer rates in 1972. Data are ppm
vjr\~_ M 69
17 Nitrate-N (ppm) in soil profiles as a result of different
applications of NH(NO ) fertilizer in 1973. 70
18 Nitrate-N (ppm) NO -N, in ceramic sample extracts at 76 cm
and 106 cm depths. Ca(NO )~ fertilizer was added in 1972
and NH,(NO ) fertilizer added in 1973. 73
19 Nitrate-N content in drainage waters collected in 1973. 7^
20 Nitrate-N (ppm) in soil profiles as influenced by manure
rate applied. Sampled June 28, 1972. Manure applied
May 1972. 76
21 Nitrate-N (ppm) in soil profiles as influenced by manure
rate applied. Sampled October 7, 1972. 78
22 Nitrate-N (ppm) in soil extracts from ceramic samples at
106 cm depth in 1972 as influenced by manure treatment. 79
23 Nitrate-N (ppm) in soil profiles as influenced by manure
treatment, sampled on June 20, 1973.
24 Nitrate-N (ppm) in soil profiles as influenced by manure
treatment, sampled on September 19, 1973.
25 Nitrate-N (ppm) in soil extracts from ceramic samples at
106 cm depth in 1973 as influenced by manure treatment. 82
26 Comparison of electrical conductivity versus NO -N
collected from ceramic samplers from manure plots in both
1972 and 1973. 84
27 Comparison of electrical conductivity versus NO^N collected
from ceramic samplers from manure plots treated in 1972. 35
IV
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TABLES
No. Page
1 INFLUENCE OF THE SIZE OF At INCREMENTS ON THE SALT CON-
CENTRATION PROFILE AT DIFFERENT TIMES. 20
2 COMMERCIAL FERTILIZER NITROGEN TREATMENTS ESTABLISHED
IN 1972 ON THE HULLINGER FARM. 24
3 FERTILIZER TREATMENTS APPLIED TO BARREL LYSIMETERS IN
1972. 27
4 TOTAL IRRIGATION WATER APPLIED, NUMBER OF IRRIGATIONS,
AND AVERAGE EC OF IRRIGATION WATER ON HULLINGER FARM. 31
5 CUMULATIVE DRAINAGE IN 1972 (STARTING 6-28) AND 1973
(STARTING 6-18). 32
6 PIEZOMETER IDENTIFICATION NUMBER. 34
7 AVERAGE WATER TABLE DEPTH DURING IRRIGATION SEASON UNDER
FIELD PLOTS ON THE HULLINGER FARM. 35
8 CUMULATIVE SALT FLOW FROM THE DRAINS IN 1972 (STARTING
6-28) AND 1973 (STARTING 6-18). 37
9 SUMMARY OF THE ELECTRICAL CONDUCTIVITY OF WATER COLLECTED
FROM CERAMIC CUPS AT 106 cm DEPTH AND FROM THE DRAINS
OF VARIOUS PLOTS. 39
10 WATER CONTENT, 1:5 ELECTRICAL CONDUCTIVITY, AND 4-PROBE
CONDUCTIVITY (VERTICAL 4-PROBE) FOR FIELD TRIAL 3 FIRST
RUN. 44
11 COMPARISON OF ELECTRICAL CONDUCTIVITY, EC, OF SAMPLES
EXTRACTED FROM CERAMIC SAMPLERS WITH 1:5 SOIL SOLUTION
EXTRACTS. VERNAL, UTAH, AUG, 9-10, 1973 FOR FIELD TRIAL
3 SECOND RUN. 45
12 CHEMICAL ANALYSIS OF SOIL SOLUTION (FROM SATURATION
EXTRACT) AND WATER SAMPLES. AUGUST 10, 1973. ANALYSES
BY USU SOIL TEST LAB. 47
13 ELECTRICAL CONDUCTIVITY BY THE HORIZONTAL 4-PROBE MEASURED
AT VERNAL, UTAH ON AUGUST 8-10, 1973. 48
14 ELECTRICAL CONDUCTIVITY, EC, FROM CERAMIC SAMPLERS, 1:5
SOIL EXTRACTS AND WATER CONTENT AS A FUNCTION OF TIME
AND DEPTH AT FARMINGTON, UTAH, SEPTEMBER 9-10, 1973. 50
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TABLES (Continued)
No.
15 ELECTRICAL CONDUCTIVITY AS MEASURED BY THE HORIZONTAL
4-PROBE AT FARMINGTON. 51
16 WATER CONTENT AND VERTICAL 4-PROBE EC AND 1:5 SOIL
EXTRACT FOR LOGAN, JULY 2-3, 1973 TRIAL. EC IN mmho/cm. 51
17 RELATIVE PROPORTION OF ROOTS AT DIFFERENT DEPTH INCRE-
MENTS AT MATURATION ASSUMED, 58
18 COMPARISON OF IRRIGATION WATER APPLIED AND INITIAL SALT
CONCENTRATION ON RELATIVE TRANSPIRATION, T/T , TOTAL
WATER USED, DRAINAGE, SALT FLOW TO THE GROUNDWATER AND
AVERAGE FINAL SALT CONCENTRATION FOR THE DEEP-ROOTED CROP. 59
19 COMPARISON OF IRRIGATION WATER APPLIED AND INITIAL SALT
CONCENTRATIONS ON RELATIVE TRANSPIRATION, T/Tp, EVAPO-
TRANSPIRATION, ET, DRAINAGE, SALT FLOW TO THE GROUNDWATER
AND AVERAGE FINAL SALT CONCENTRATION FOR THE MEDIUM-
ROOTED CROP. 61
20 COMPARISON OF IRRIGATION WATER APPLIED AND INITIAL SALT
CONCENTRATION ON RELATIVE TRANSPIRATION, T/Tp, EVAPO-
TRANSPIRATION, ET, DRAINAGE, SALT FLOW TO THE GROUNDWATER
AND AVERAGE FINAL SALT CONCENTRATION FOR THE SHALLOW-
ROOTED CROP. 62
21 SOIL N03-N CONTENTS IN SOIL SAMPLES TREATED WITH VARIOUS
RATES OF NH4N03 AND PLANTED TO CORN OR ALFALFA. HULLINGER
FARM, VERNAL, UTAH, 1973. 71
22 N03-N LOSS FROM JUNE 20 TO SEPTEMBER 19, 1973. 71
23 ELECTRICAL CONDUCTIVITY (EC) OF SOIL SOLUTIONS TAKEN
USING POROUS CERAMIC CUPS INSTALLED AT 106 cm DEPTHS.
HULLINGER FARM, VERNAL, UTAH, 1972. 86
24 N03-N MEASUREMENTS MADE IN THE BARRELS. 88
25 GRAIN YIELDS FROM CORN IN 1973 AS INFLUENCED BY COMMERCIAL
FERTILIZER TREATMENT, 90
26 YIELDS OF CORN AND SUDAN GRASS IN 1972 AND CORN IN 1973 ON
THE MANURE PLOTS. YIELDS ARE IN FRESH WEIGHTS. 90
Appendix Tables
B-l Climatic data for 1972. 110
vi
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TABLES (Continued)
No. PaSe
B-2 Lysimeter evapotranspiration (ET) and temperature (T) data
for 1973.
B-3 Dates of irrigation, amount applied, and EC of irrigation
water on Hullinger farm in 1972, 115
B-4 Dates of irrigation, amount applied, and EC of irrigation
water on Hullinger farm in 1973. 117
B-5 Discharge of tile drains on Hullinger farm in 1972. A
blank in the data indicates no flow. 118
B-6 Discharge of tile drains on Hullinger farm in 1973. 120
B-7 Water table depth and elevation at selected piezometers on
Hullinger farm in 1972. 122
B-8 Water table depth and elevation at selected piezometers on
Hullinger farm in 1973, 126
B-9 EC of tile drain effluent on Hullinger farm in 1972. 129
B-10 EC of tile drain effluent on Hullinger farm in 1973. 131
B-ll Electrical conductivity of samples withdrawn from ceramic
cups (106 cm depth) in commercial fertilizer plots treated
with Ca(N03)2 in 1972, 133
B-12 Electrical conductivity of samples withdrawn from ceramic
cups (76 and 106 cm depths) in commercial fertilizer plots
treated with NH.NO. in 1973. 134
4 3
B-13 Computations of EC derived from measurements with the 4-
probe field system during 1972 field trials in Vernal. 135
B-14 Initial (6-28) and final (10-7) soil tests in plots 1972
for N-M>. 136
B-15 Initial (6-20) and final (9-19) soil tests in plots 1973
for N-N03. 137
B-16 N-NO- in commercial fertilizer plots treated with various
rates of NH.NO- collected from ceramic samplers in 1973
from 76 cm and 106 cm depth, 138
B-17 N-N03 in commercial fertilizer plots treated with various
rates of Ca(NO_)_ collected for ceramic samplers (106 cm
depth) in 1972? 139
vii
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TABLES (Continued)
No. Page
B-18 N-N03 of tile drain effluent on Hullinger farm in 1972. 140
B-19 N-NO of tile drain effluent on Hullinger farm in 1973. 142
B-20 Initial and final soil tests in manure plots 1972 for
N-N03. 144
B-21 N-NO in the manure plots in 1972 collected from ceramic
samplers at 106 cm. 145
B-22 Initial and final soil tests manure plots 1973 for N-NO , 147
B-23 N-NO^j in manure plots in 1973 from ceramic samplers at 106
cm depth. Manure application rates in mt/ha (dry weight). 148
B-24 Electrical conductivity of samples withdrawn from ceramic
cups (106 cm depth) in manure plots in 1972, Manure appli-
cation rates in mt/ha (dry weight). 149
B-25 Electrical conductivity of samples withdrawn from ceramic
cups (106 cm depth) in manure plots in 1973. Manure appli-
cation rates in mt/ha (dry weight). 151
B-26 N-NO- from the barrel lysimeters in 1972. 152
B-27 N-NO measured in the barrels in 1973. 153
B-28 Electrical conductivity of water samples from the barrel
lysimeters in 1972. 155
Vlll
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ACKNOWLEDGMENTS
Many individuals assisted, encouraged, and supported the work leading
to this report. The authors would particularly like to acknowledge
the help of Dr. Vaughan E. Hunsaker and Dr. Raymond W. Miller on the
nitrogen aspects of the research. Dr. Miller was instrumental in
analyzing results of the nitrogen movements. Dr. L. S. Willardson
assisted in writing the revision.
The authors express special appreciation to R. B. Backus and R. D.
Bliesner who served as farm managers in residence in Vernal for the
1972 and 1973 growing seasons, respectively. Through their efforts
smooth operation of the field research was accomplished.
ix
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SECTION I
CONCLUSIONS
1. The drain discharge on the Hullinger farm is rather insensitive to
irrigation management practices on the farm itself but instead depends
upon practices of farmers over a much larger area. Any irrigation
management plan for return flow quality control must include the major
part of a hydrologic unit in order to be successful.
2. Salt storage in the soil profile above the bottom of the root zone
is indicated by the high values of drain effluent EC for small
infrequent drain flows. This salt storage is not a direct result of
the irrigation management practiced since research work began on the
Hullinger farm but has been developed over long periods of time.
3. Water table depth appears to be a significant factor affecting salt
storage in the soil profile and return flow quality where water
application approaches or is less than evapotranspiration requirements.
4. The total seasonal salt discharge from the tile drainage system was
directly related to the quantity of water discharged. Therefore,
management of water is the key to successful return flow quality
management. Any control plan which will reduce total discharge of
water will probably also reduce total discharge of salts, at least over
the short term. The period of effectiveness of such a plan is difficult
to ascertain but the period would be of several years duration.
5. Precipitation and solution mechanisms play an important role in
salt movement through Hullinger farm soils. The soils have a high
"buffering" capacity. This supports the foregoing conclusion that
quantity of water flow is the controlling factor. Since the EC of the
soil solution at any given depth is essentially constant with time
under the management variables that have been imposed in this experi-
ment, the salt movement into drains is simply the product of the salt
concentration and the water inflow rate.
6. The model developed and used for prediction purposes was limited to
simple salt flow where solution and precipitation of salts within the
soil were not considered. The model predicted that under several
irrigation management variations, yield was not influenced until salt
accumulations which took several years occurred. The results predicted
were strongly influenced by the presence of the water table and the
depth of the plant root zone assumed. Modifications of the model,
to account for precipitation, solution and exchange, etc., did not
significantly improve the prediction when applied to the Hullinger farm
data.
7. Appreciable amounts of NO--N moved into drainage water at depths of
at least 106 cm from manure additions of 216 mt/ha (dry) or from
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commercial fertilizer applications of 440 kg/ha N as Ca(NO»)~ or
NH.NCL. Concentrations of over 30 ppm N03-N were measured in drain
water under the commercial fertilizer plots.
8. Additions of manure at rates of 108 mt/ha (dry) increased NO_-N
content in the soil to levels greater than 20 ppm, even the year after
application. This is more than 2 to 3 times NO~-N concentrations of
control plots.
9. NO_-N reductions during the growing season approached 300 kg/ha for
applications of 440 kg/ha N as Ca(NO,)_.
10. Salt increases were noted at the 106 cm depth under plots
receiving heavy manure applications.
11. Submergence of tile drains can reduce NO_-N concentrations in the
effluent. One drain was successfully submerged so that the water table
was always at or above the top of the gravel envelope during the
irrigation season. The NO--N concentration of effluent from this drain
was significantly lower (by a factor of about 1/2 to 1/4) than the
drain receiving the same fertilizer application but flowing freely
and having air within the drain pipe.
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SECTION II
RECOMMENDATIONS
1. The results of this study indicate that with approximately yearly
monitoring of soil salinity status and appropriate irrigation manage-
ment, salt can be stored in the soil profile for several years with
little yield decrease. However5 over the long period of time salt
balance must be maintained. For soils with little "buffering" capacity,
the model predictions indicate that irrigation management procedures
are available that will allow yield maintenance with no drainage for
a few years.
2. The soils like those on the Hullinger farm will allow salt storage
in the profile with no drainage, with little yield decrement, because
large amounts of salt are precipitated with a minimum of salt buildup.
With yearly monitoring of salinity status it is probable that a no-
drainage system would function satisfactorily for approximately 10
years before significant yield decreases would result. However, over
a long time, salt balance would have to be maintained.
3. Highly buffered soils, like those studied from the Hullinger farm,
will load the drainage water with soluble salts in direct proportion to
the drainage water amount since the soil solution concentration is
essentially constant. Yearly monitofing of the soil solution concen-
tration in the drains would appear to be sufficient to predict the
salt load provided the water flow can be measured. Additional research
is needed to characterize the soil physical and chemical properties of
these highly buffered soils.
4. Prediction of water flow into the drains based on predictions of
evapotranspiration, irrigation amount, precipitation and soil water
storage will probably have an error of about 100 percent. This is due
to errors of about 10-20 percent in predicting evapotranspiration and
soil water storage, and nonuniform irrigation and rainfall. Thus it
is unlikely that low leaching irrigation management schemes can be
attained on a farm field scale.
5. Significant decreases in salt flow into the drainage water without
yield decreases in a region like the Vernal, Utah site can be attained
by decreasing the leaching of the present irrigated farms (estimated
to be 10-100 percent of irrigation requirement). However, this will
only be possible (if the site studied is representative) by conversion
of the present valley-wide gravity irrigation system, with a poor
irrigation uniformity, to a system capable of much more uniform water
application. While it is questionable whether this conversion would
be economically feasible under present conditions for the local farmers,
with the many human factors that would cause problems, this type of
solution would surely compare with the alternative solution of
desalinization plants.
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6. It is recommended that any procedures suggested to control
irrigation return flow be applied to complete hydrologic units. The
results reported herein show that drainage flow and quality on the
experimental farm were almost entirely controlled by irrigation of
surrounding farms.
7. It is recommended that an irrigation management system involving
several years of salt storage with no drainage, be followed by a leach-
ing period to minimize nitrate movement into the drainage water and
maximize use of the NO_-N fertilizer. The most efficient use of such a
system would require periodic salinity and nitrate monitoring and
control of fertilization and irrigation water application.
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SECTION III
INTRODUCTION
Irrigated agriculture has historically been concerned with water supply,
diversion and conveyance of water to the farm, and use of water on the
farm. The disposal or return of excess water to the stream was a point
of lesser concern. The main emphasis has been on quantity rather than
quality of water. Salinity has long been recognized as an important
parameter influencing the suitability of water for use as an irrigation
supply. The amount and kinds of salt existing in soils have been
used for assessing their suitability for receiving irrigation water.
In all of these activities, attitudes of persons involved have usually
been that the quality of the irrigation return flow was not of too much
consequence or that it was a natural result of activities necessary for
the maintenance of the agriculture of an area and not subject to much
control.
The salinity problem in the Colorado River Basin is emphasized by a
report (EPA, 1971) the conclusions of which include:
1. Salinity (total dissolved solids) is the most serious water
quality problem in the Colorado River Basin.
2. Salinity concentrations in the Colorado River system are
affected by two basic processes:
(a) salt loading, the addition of mineral salts from
various natural and man-made sources; and
(b) salt concentrating, the loss of water from the system
through evaporation, transpiration, and out-of-Basin
export.
3. Salinity control in the Colorado River Basin may be
accomplished by the alternatives of:
(a) augmentation of Basin water supply;
(b) reduction of salt loads (including improvement of
irrigation and drainage practices);
(c) limitation of further depletion of Basin water supply.
Irrigation return flow constitutes a very large part of the water
influent which reaches the streams and rivers of the Colorado River
Basin. Thus, salinity and irrigation return flow are vitally linked
in the overall problem. Indications of the importance of the problem
are given by several recent events including, but certainly not
limited to, the following:
1. The aforementioned report on the mineral quality problem
in the Colorado River Basin;
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2. The February 1972 sessions of the Federal-State Enforcement
Conference on the Colorado River held in Las Vegas;
3. Discussions of Colorado River salinity problems between the
Presidents of the United States and Mexico;
4. The Western Regional Research Project, W-129, entitled
"Salinity Management of the Colorado River Basin" supported
by the Agricultural Experiment Stations of the seven Basin
states and the Cooperative State Research Service;
5. The National Conference on Managing Irrigated Agriculture
to Improve Water Quality held in Grand Junction, Colorado,
May 1972;
6. The decision to build a desalting plant near Yuma, Arizona,
to handle the effluent from the Welton-mohawk project.
It was concluded (EPA, 1971) that salinity control in the Colorado
River Basin may be accomplished in part by improvement of irrigation
and drainage practices. Evaluation and preassessment of such improved
practices depends upon knowledge of water and salt movement through
the root zone of the crops. Return flow of water to streams from
irrigation water applied to fields is profoundly influenced during its
flow through the soil. There is, first of all, decrease in the amount
of the irrigation water that might appear as return flow because of
vapor loss to the atmosphere during the evapotranspiration process.
The amount of water returned may be zero but, under present irrigation
and drainage practices, commonly ranges from 10 to about 50 percent of
the irrigation water applied. Since soluble salts are mostly excluded
during plant uptake of water and thus are left behind in the soil
during evaporation, there is a concentrating effect of the salts in
the soil solution drained compared to the soil solution resulting
from applied irrigation water. The water draining from the soils may
contain such a high salt concentration that its further use is severely
limited. In addition to the concentrating effect of evapotranspiration,
the natural weathering of soils, chemical precipitation, solution and
exchange of constituents in the soil solution with the solid soil
particles further influences the concentration of the soil solution.
Analysis of the total process is complicated by the time delay, amount
of salt going into root zone storage, and in movement of constituents
in the soil water from one part of the soil to another.
Previous research (King and Hanks, 1973) conducted by Utah State
University indicates that there is considerable promise for exercising
control of return flow quality by proper irrigation management. The
basic premise underlying the research effort has been that the soil
profile above the water table can be used as a temporary salt storage
reservoir. Then, by proper management of irrigation, this salt may be
released by leaching only when desired. Soil profile leaching is not
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necessary every year. Recent work (Bernstein and Francois, 1973)
using greenhouse lysimeters supports the idea of salt storage and
indicates that very small leaching fractions can be used over extended
periods of time without adversely affecting yield of crops.
King and Hanks (1973) reported the development and testing of two
independent mathematical models of water and salt movement through the
soil with extraction of water by evapotranspiration. They concluded
that the best model for irrigation management would probably result
from a combination of the two. They recommended that further model
development be done to reduce required computer time and eliminate the
inherent numerical dispersion in the model affecting prediction of
salt movement. They also suggested that time dependent root develop-
ment and extraction pattern be incorporated into the model.
Other recommendations from the earlier work (King and Hanks, 1973)
include suggested improvement of data collection procedures in the
field for data to be used for model verification. The need for better
definition of the soil solution electrical conductivity profile was
cited. The earlier work also concluded that control of the quality of
soil profile effluent will require precise control of water on the farm,
particularly the depth and timing of irrigations. It was suggested
that some of the costs of establishing adequate water management systems
could result in benefits other than increased control of drainage
water quality. Study of the economics of irrigation management were
recommended. Using one of the models, King and Hanks (1973) tested
the timing of irrigation as a management variable. With all other
conditions the same, results showed that as the time interval between
irrigations increases, the season totals of salt removed from the root
zone, the salt remaining in the profile, and the amount of water
required for leaching tend to become constant. However, the irrigation
frequency has a significant effect upon when the salt is discharged
during the season.
In the Ashley Valley of Utah, irrigation practices largely influence
the quantity and quality of irrigation return flow. This is also
true in many other areas of the Colorado River Basin and the United
States. The research covered by this report included study of the
degree of control of quantity and quality of return flow which is
possible through management on the farm irrigation, drainage, and
fertilizer application practices.
OBJECTIVES
The primary objectives of this research were to study various farm
management practices related to irrigation and drainage and fertilizer
use; and to determine their effects upon the quality and quantity of
irrigation return flow.
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The specific objectives were:
1. To monitor the movement of dissolved salts through the soil
profile into the drainage water under different irrigation
and/or drainage management practices.
2. To demonstrate the degree of control over the quality of
the drainage water as influenced by these management
practices.
3. To monitor the movements of nitrogen from applied commercial
fertilizer and animal wastes through the soil profile and
into the drainage water.
4. To evaluate the effects of various irrigation and/or
drainage management practices upon these movements of
nitrogen.
5. To develop management models which will describe these
movements and allow for extrapolation of the results obtained
from the Ashley Valley research farm to other conditions in
other areas.
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SECTION IV
METHODS
GENERAL
It is necessary to discuss some general aspects of the research farm
and field data collection before focusing attention on the detailed
studies of salt and nitrogen movement. Most of the field work reported
herein was conducted on the Hullinger farm near Vernal, Utah. The
location of the facilities existing on the farm immediately prior to
initiation of this research were reported earlier (King and Hanks,
1973).
Drainage System Modification
The original tile drainage system consisted of six parallel drains
originating at the north boundary of the farm and discharging separately
into the Naples drain (a natural drainage channel). Drains 1 through
5 were spaced 61 m apart and drain 6 was 107 m west of drain 5.
In an effort to create more field plots underlain with a tile drain,
the original system was modified during May and June 1972. A water-
tight collector line was added in the east-west direction intersecting
the drains about 70 m south of the north boundary of the farm. The
collector was about 30 cm deeper than the drains. Water entered the
collector only at the manholes into which the drains discharge. Every-
where else the collector was a water-tight pipe. Figure 1 shows the
location of the collector drain with respect to the original tile
drains.
The construction in 1972 also included the removal of a 6.4 m section
of drain and gravel envelope from the six original tile drains to
separate the drains into 3 sections. This separation was made about
140 m south of the north boundary of the farm. At the separation,
each end of the remaining drain was plugged and soil material was
compacted back into the trench excavated for removal of drain pipe
and gravel envelope. Figure 1 shows the new drain configuration in
which the new drains are designated such as 2N, 2M, and 2S meaning the
north part of drain 2, the middle part of drain 2, and the south part
of drain 2, respectively. Also shown in Figure 1 is a new drain 5A
(SAN, SAM, 5AS) installed in three separate parts corresponding to the
modified drains and 61 m west of drain 5.
In the modified drainage system, all south drains discharged into the
Naples drain through separate manholes as in the original system. The
middle drains flowed to the north and discharged into manholes at the
collector. The north drains flowed south to the collector manholes.
The system allowed measurement of discharge and water quality of each
drain separately at the manholes.
-------
I
I
o
hh
W
I
fi
m
Pi
O
3
o
s
n
H
i h
i
' i
LEGEND:
KIIJ
N
TRAILER
LOCUTION
PIEZOMETER
G*TE
LY5IMETER
PUMP
DRAIN LINES
SPRINKLER MAIN LINE
FENCE
GROUND SURFACE CONTOUR
MANHOLES
OBSERVATION HOLES
WELL TO SH»I_£
EVAPORATION PONO
<<
H
i '
IRRIGATION BLOCKS (USUALLY 4 LATERALS]
ANEMOMETER. HUMIDITY SENSOR, THERMOPILE
4 PROBE SENSOR
6 PROBE SENSOR
LYSWETEB SWNDPIPES
RAIN GUAGt
ACCESS
ACCESS
ACCESS TUBES AND TENSIOMETERS
ACCESS ROADS
SMALL BASIN
TUBES. TCNSOMETERS, SALT CUPS.
TUBES
SALT SfNSORS, 4 OBe SENSOR
-------
Irrigation Management Practices
Most of the work on some small field plots was designed to concentrate
on the nitrogen movement rather than total dissolved solids (salinity).
The salt movement was studied by separate field trials as explained
in detail later. The irrigation and drainage management practices on
the large plots over drains 3N,4N, 5N, SAN, 6N, 3M, AM, 5M, 5AM, 6M,
3S, 4S, 5AS, and 6S were designed with a dual purpose of studying both
nitrogen and salt movement. The methods for collecting data which were
common to both purposes is described under the heading "General Field
Data."
The drainage management variable involved submergence of some of the
drains to obtain anaerobic conditions in the drain pipe. Drains 5N and
5M were submerged by placing an elbow and short standpipe on the outlet
end of each drain within the manhole at the collector. The overflow
rim of the standpipe was about 25 cm above the invert of the drain
pipe. Thus, the water table should have been at or above the top of
the gravel envelope all along the drain in order for any water to be
discharged from the drain. All other drains were free to flow un-
restricted.
The irrigation management for 1972 is depicted on Figure 1. This
involved two different water treatment levels, 1.1 and 1.5 times ET
in which ET was the evapotranspiration of alfalfa as measured by two
lysimeters near the center of the farm on either side of drain 3M.
For 1973, irrigation water was added to the crop whenever soil moisture
decreased to a predetermined level in the lysimeters.
General Field Data
The methods for collecting data which were common to both salt and
nitrogen movement studies are reported here.
Evapotranspiration and Climate - Evapotranspiration was measured with
hydraulic lysimeters. Global (solar) radiation was measured with an
Eppley pyranometer and integrated electrically. Measurements of wet
and dry bulb temperatures were made manually with a psychrometer. Some
climatic data were taken from the local weather station at the airport
which is about 0.8 km away. The data were analyzed in the same manner
as outlined in the report for previous years (King and Hanks, 1973).
Drain Discharge - The discharge of the drains was obtained by measuring
the time required to fill a container of known volume (bucket-stop
watch method). These measurements were taken once a day (except week-
ends) for each drain which was flowing.
Drain Effluent EC - Each time drain discharge was measured a sample of
the drain effluence was collected. Measurements of the electrical
11
-------
conductivity (EC) and the NO_-N were made after the samples were
brought into the laboratory. The EC was measured with, a laboratory
bridge and was reported as mmho/cm at 25 C.
Irrigation Water EC - The EC of the irrigation water was measured in
the field with a portable conductivity meter which internally corrected
all EC values to 25 C when a dial on the instrument was set by the
operator to the water temperature of the sample. The measurements were
made on samples withdrawn during each irrigation from the pond near the
pump inlet by an automatic water sampler at a pre-set time interval.
Water Table Depth - Water table depth was measured weekly during the
irrigation season at the piezometer locations shown on Figure 1.
Details of the piezometers were explained earlier (King and Hanks,
1973). Since the elevation of the top of the piezometer was known,
water table depth could be used to obtain water table elevation and
hydraulic gradients in the groundwater.
SALT MOVEMENT
Field Studies
To accomplish the parts of objectives 1 and 5 relating to the field
evaluation of the salt flow component of a model, it was necessary to
conduct field tests. Earlier work (King and Hanks, 1973) indicated
that the soil salinity status did not change as measured by salinity
sensors and 4-probe sensors. Thus, Gupta (1972) artificially applied
large amounts of salt to the soil surface in order to get measurable
differences in the salinity status of the soil solution. Results from
the models showed reasonable agreement with his field trial. Since
there was some uncertainty about the field measurements and the model
estimation of such an unnatural situation, the following additional
field studies were conducted.
Field Trial 1 - In 1972 an evaporation pond (Figure 1) was constructed
and filled with water early in the year. This was done to provide a
source of salty water that would be similar chemically to the water
used for normal irrigation but with. a. higher salt concentration. In
previous studies dry salt was added to the soil surface. This
technique resulted in a salt distribution in the soil that could not
be completely explained other than by some indeterminate solution-
dissolution function needed to establish boundary conditions for model
evaluation. Since dry salt application was considered an abnormal
situation, the evaporation pond method of supplying salty irrigation
water was selected.
A new method of evaluating the electrical conductivity (EC) of the soil
solution was also tested. This involved a field modification of the
laboratory technique discussed by Gupta and Hanks CL972) where the
four-probe EC was measured at 15-cm intervals up to 180 cm. According
to the theory, this would allow for determination of the soil EC by
12
-------
15-cm increments down to 180 cm. Measurements of soil water content
were also needed to estimate the electrical conductivity of the soil
solution for correction of the measurements. This was done with both
neutron and gamma probes.
The apparatus for the 4-probe EC method is shown in Figure 2. The
conductivity bridge was connected through a switch to the electrodes.
The switch position selected the electrode spacing. By taking
conductivity readings at different electrode spacings on the soil
surface it is possible, according to Barnes (1954) to determine the
resistivity as a function of depth. For example, the conductivity
(mho) at the 15-30 cm depth is given as
^5-30 = ^-30 ~ K0-15
the conductivity (mho/cm) can be given by
rr, u / N ^5-30
K(mho/cm) » ^ p
where D is the inner electrode spacing (cm). The conductivity bridge
used was Model R30, Soiltest, Inc., 2204 Lee St. Evanston, Illinois
60202.
For evaluation of the salinity model, a site (designated "small basin"
on Figure 1) was selected near neutron access tube B in plot 3M. In
1972 an area about* 3 by 6 meters was enclosed by a soil "dike"
constructed symmetrical to site B. Site B had tensiometer cups at
depths of 15, 46, 76, 107, and 137 cm which were used to extract soil
solution. Access tubes for neutron and gamma probe readings were also
located there.
By the first part of August 1972, sufficient water had been evaporated
from the evaporation pond that the EC of the water was 8.0 mmho/cm.
This water was pumped onto the "small" basin August 9. The evaporation
pond was re-filled with low quality water from Naples drain and the
"small" basin was re-filled with this water (EC =4.1 mmho/cm) on
August 10.
Before each addition of water to the basin, the soil moisture content
variation with depth was obtained with both neutron probes and the soil
salinity status was monitored with the 4-probe apparatus. After each
addition of saline water, the above measurements were repeated
periodically. Also, soil solution samples were extracted from the
porous cups. At the end of the trial, soil samples were taken.
Field Trial 2 - After the August 10 irrigation of the small basin,
water from Naples drain was again pumped into the evaporation pond and
allowed to concentrate until mid-September when another field test was
made. On September 19 water from the evaporation pond (EC = 4.7
mmho/cm) was added to the small basin. Then on September 20 a high
13
-------
Q. 0
SOIL TEST ~'~p|«
MODEL R 30
R A 1 ft F* /"\ ft J 1 1 ft f* f\ fcl r\ 1 I rf"»T 1 \ * IT"\/ ^^^L.»H
MICROMHO CONDUCTIVITY f-9^
MFTFR /-«
DEPTH ELECTRODE SWITCH POS
C, P| P2C2
O-l5cm 13 14 15 16 1
O-30 II 13 15 17 2
O-46 10 13 16 19 3
0-61 9 13 17 21 4
0-76 8 12 17 22 5
0-91 7 II 17 23 6
0-107 6 11 18 24 7
0-122 5 II 19 25 8
- 137 4 10 19 26 9
0- 152 3 9 19 27 10
0-168 2 9 20 28 II
0-183 19 21 29 12
12
SWITCH
4 POLE
POSITION
29 WIRE CABLE
j
i i i i i i i i i r n M i M rn i m i
2 4 6 8 10 12 14 16 18 20 23 24 26 28
13 57 9 II 13 1517 192122 26 27 29
216'
Figure 2. Schematic diagram of 4-probe conductivity apparatus
with associated switching arrangement.
14
-------
quality water from the irrigation pond CEC - 1.1 nnaho/cm) was added.
For Field Trial 2 the procedures of data collection were the same as
for Field Trial 1.
Field Trial 3 - Early in 1973 tests were made on plots near the
irrigation pond in which water of various qualities were added to a
ponded area. A much more intensive set of ceramic samplers was
installed at various depths for soil solution sampling. Soil samples
were taken before and after the tests. Four-probe readings were taken
frequently throughout the tests. Corresponding neutron probe readings
were made to obtain soil water contents. A portion of the irrigation
water was pumped first into barrels where sufficient NaCl was added to
bring the water up to an EC of about 10 mmho/cm. The sequence of water
application was: (1) normal irrigation, (2) "salty" irrigation, (3)
normal irrigation. This trial was conducted twice in 1973.
Measurement of pH, EC Ca, Mg, Na, S04, Cl and HC03 were made by the USU
Soil Testing Laboratory on soil samples collected during the tests.
Some of the water samples extracted from the ceramic cups were also
analyzed for the above list. The rest of the water samples were
analyzed for EC only. To estimate the amount of precipitated salts,
measurements were also made on water extracted from the soil samples
after dilution with distilled water at the ratio of 1/100 (soil/water).
Field Trial 4 - Additional field tests were made later in 1973 at the
USU farm at Farmington, Utah, to assess the effect of a different soil
on salt and water movements. Due to the difficulty of getting uniform
water distribution under the previously used flooding techniques (Field
Trials 1, 2, and 3), a new method was devised to apply water at
Farmington. The water was applied using a large number of irrigation
"drippers" arranged to wet the area without flooding. The infiltration
rate of this soil was very low so some surface movement of water
occurred but this was a small proportion of the total applied. Thus,
the drip irrigation technique essentially solved the problem of uneven
water distribution experienced in the flooding treatments. The sequence
of water additions and the system of data collection was similar to
Field Trial 3.
Field Trial 5 - An additional field trial at Logan, Utah was performed
where another type of 4-probe conductivity tester called the "vertical
4-probe" was constructed and tested. This probe consisted of a 1.3
cm diameter fiberglass rod 122 cm long with a handle at one end and
a sharp point on the other end. About 5 cm, from the pointed end, a
stainless steel ring slightly larger than the rod served as the
bottom electrode. Three other similar electrodes at 5-cm spacing
along the rod gave the 4-probe configuration. By inserting the rod
into the soil at different depths, readings could be obtained of soil
salinity in a vertical profile as a function of depth. This unit was
designed to sample a small volume of soil. In practice it was found
that the fiberglass rod was too flexible to push into the soil without
first making a hole with a steel rod.
15
-------
In the Logan tests a small basin about 1 m x 1 m was used. Water of
various electrical conductivities (details in Section V, Results) was
added in these tests. Water contents were measured with the neutron
probe and EC was measured from soil samples by the 1:5 extract method.
The vertical 4-probe equipment was also tested at Vernal during Field
Trial 3.
The vertical 4-probe system has the disadvantage that the geometry of
the electrical flow paths is not precisely known so it is impossible
to convert the readings to mho/cm. The volume sampled is also
uncertain. Tests in a water tank indicate that the volume sampled is
a sphere of about 46 cm diameter. For the purpose of this field trial
the relative readings given by the vertical 4-probe conductivity tests
were considered sufficient for evaluation.
Laboratory Studies
Laboratory Trial 1 - This trial was run to determine in more detail the
"buffering" or "salt source" characteristics of the soil from the
Hullinger farm. Representative soil samples having various soil-water
content ratios were prepared. The solution was extracted from the
samples having soil water ratios ranging from 0.5 to 2.0. The
electrical conductivity of the extract from each sample was measured
and the relative amount of dissolved salts was determined.
Laboratory Trial 2 - A short-column leaching experiment was conducted
in the laboratory to determine the order of magnitude of the relative
change in concentration of the soil solution as a function of depth
and time. The suitability of the 4-probe EC method for following the
salinity of the soil solution in short columns during leaching was also
evaluated in this trial.
The short soil column, consisting of three cylindrical segments each
5 cm high, was irrigated with "tap water" having an EC of 0.31 mmho/cm.
Four electrodes were located in the cylinder wall along a horizontal
circumference line 2.5 cm from the end of each segment. These four
electrodes were connected to the conductivity bridge described earlier
to measure the four-probe electrical conductivity, EC (4P). Measure-
ments as functions of time were made of the quantities of water enter-
ing and leaving the column, the EC of the inflow and outflow, and EC
(4P) of each segment.
Model Modifications
In order to accomplish objectives 1 and 5 it was considered necessary to
modify the models described earlier (King and Hanks, 1973). It was
concluded that the so-called simple model for water flow in the soil
profile was not useful for further evaluation because of the inability
of the model to account for upward flow. Thus it was decided to
16
-------
concentrate on modification of the more detailed model to be used as
a water management tool to control the quantity and quality of
irrigation return flow.
As reported by King and Hanks (1973) the detailed model predicted
water flow quite well but was less satisfactory for predicting salt
flow. Consequently a major effort was made to improve the salt
flow computational methods. Further modification was also made of
the model to allow for a developing root system for annual crops like
corn. A further major modification involved an addition to the model
of a procedure to predict plant growth as influenced by both water and
salinity management. These modifications are outlined in the follow-
ing discussion. The computer program printout is listed in Appendix A.
Salt Flow - The original model was limited in its ability to describe
salt movement because diffusion and dispersion were not considered and
because the numerical procedure used caused additional numerical
dispersion (i.e., the results were influenced by the numerical
techniques used) . Consequently the anti-numerical dispersion modifi-
cation is similar to that outlined by Bresler (1973) but was adjusted
to account for varying depth increments (Bresler assumed equal depth
increments). Further modification was made, after Bresler (1973), to
include diffusion and dispersion. The general salt flow equation used
was
where C is salt concentration, 6 is volumetric water content, D is the
combined diffusion and dispersion coefficient, q is mass flux of water,
z is depth and t is time. This equation does not account for any
precipitation or solution of salts within the profile.
The uncorrected numerical approximation of the left-hand side of
equation [1J , used was
3t
= Cc1J+19±J+1 - c±J e±d) /At [2]
where i refers to the depth increment and j is the time increment
and At = tj+1 - tj.
The anti-numerical dispersion correction added to the right side of
equation [2] was
17
-------
s (e.2 + l + e.2)
j+l/2 f j+l/2 (J+1/2X _ 1+1/2 (cJ+l/2 _ cJ-U/2)
CCi " Ci+l J ql-l/2 ^i-l Ci }
DLXB VJD 2 DLXA WU 2
[3]
where
DLXB = zi+1 - z.
DLXA - z± - z
J+l/2 .
un - i "i+1
WD =
2
, «2+l/2
WO =
The first term in the right hand side of equation [1] accounts for
diffusion and dispersion and has the following numerical approxi-
mation
J+l/2 _ J+l/2
3
_
3z 3z ~ DLXC . DLXA DLXC . CLXB
where
DLXC -
This numerical equation was used with no further modification. The
value for D was chosen as follows
o .UTJ./^ oi+1/2
The values used for the constants were Csee firesler, 1973)
D = 0.05
o
A - 0.001
B - 10
* =0.4
-------
The numerical approximation fo* the mass flow term, uncorrected for
numerical dispersion, was
DLXC
The following anti-numerical dispersion correction for equation [6]
was (added to the right-hand side)
CCi - ci+l)
" ^
DLXC DLXC
When the anti-numerical dispersion correction for the mass flow term,
equation [7] , was added to equation [6] the result turned out to be
the same for upward or downward flow so no checks had to be made for
flow direction.
The modified model in its present form still has two versions. The
first version considers simple salt flow only. The second version
includes the first but also has salt exchange, precipitation, solution,
etc., included according to Gupta (1972) and Dutt et al, (1972).
During the modification of the model to incorporate the corrections for
numerical dispersion (Bresler, 1973), test calculations were performed
to evaluate the adequacy of these corrections for the salt flow part
of the model. The earlier model suffered from numerical dispersion as
evidenced by significant differences in results for different sizes of
AX (depth) and At (time) increments. Table 1 shows the concentration
profiles computed with the dispersion corrected model at two different
times (t=16 and 240 hr) after an initially high salt concentration
(t=0) in the surface layer was moved into the soil by irrigation.
Note that the results for the version 1 of the model using two
different At increments are reasonably close throughout the profile
depth. The differences are well within the uncertainty that would be
caused by the physical and chemical data used. It was concluded that
the anti-numerical dispersion scheme used should give valid model
predictions.
Table 1 also shows results of computations with the version 2 for one
sequence of At increments. This version uses the numerical dispersion
corrections and accounts for salt exchange, precipitation, solutions,
etc. The results are not greatly different from the more simple version
1 of the model but do yield concentration peaks slightly lower in the
profile that have lower concentrations.
Comparison of the computed salt distribution with the field measure-
meats, as given by Gupta (1972), indicates that the computed salt
concentration peaks given by both models are 10-20 cm too close to the
soil surface. However, the field data measured are for large depth
increments which lead to some uncertainty regarding the details of the
19
-------
Table 1. INFLUENCE OF THE SIZE OF At INCREMENTS ON THE SALT CONCENTRATION
PROFILE AT DIFFERENT TIMES.
Depth
cm
1
3
5
8
12
16
20
25
30
35
40
45
55
70
85
100
115
135
155
165
C(t=0)
meq/1
2704
53
54
54
54
54
54
56
55
56
55
55
59
57
56
56
53
50
50
53
C(t = 16 hr)
At=la
meq/1 (1)
11
11
10
12
54
124
162
141
101
74
61
56
58
57
56
56
53
50
50
53
At=2
meq/1 (1)
11
11
9
7
48
125
169
145
102
73
60
56
58
57
56
56
53
50
50
53
At=l
meq/1 (2)
10
10
11
20
50
95
130
133
111
86
68
58
55
57
56
56
53
50
50
53
C(t = 240 hr)
At=l
meq/1 (1)
71
65
65
69
84
105
123
136
134
120
103
75
66
66
57
57
55
52
50
53
At=2
meq/1 (1)
68
63
64
69
85
106
126
139
137
122
103
75
66
65
57
57
55
52
50
53
At=l
meq/l(2)
35
28
37
52
70
86
105
120
122
117
108
94
76
65
59
58
54
52
51
53
aFor At = 1 the time increments are similar throughout and At = 2 the time
increments are twice as large.
(1) First version of model uses simple salt flow corrected for numerical
dispersion.
(2) Second version of model uses corrections for numerical dispersion and
accounts for salt exchange, precipitation, solution, etc.
20
-------
exact location of the salt peak. The detailed model of Gupta (1972)
does have the advantage that it predicts individual ion concentration
but the accuracy was poor. Prediction of the distribution of total
concentration of salts was more accurate than particular species
distribution.
In view of the uncertainties discussed above, it was concluded that it
would be reasonable to use the simple version of the model where
exchange, etc., is not accounted for, to predict salt movement in the
soil with occasional checks using the exchange version of the model.
In situations where irrigation was with water having greatly different
salt concentration than the previously used, model computations would
be made using the exchange version (version 2) for comparison with
calculations of the simple version (version 1).
Root Zone Extraction - This modification of the model was made to allow
for seasonal changes in the rooting depth with time. The original
model of Nimah and Hanks (1973a, 1973b) had a fixed depth and pattern
of rooting. The root zone extraction modification allowed for simula-
tions of annual crops, like corn or oats, to be used for the season
where the root extraction patterns changed with time. Three input
variables were required for the root profile to change with time up
to root maturity. The input variables were
RDFSAV(I) = Root distribution function at maturity
KDFDAY = Number of days from the start until root maturity
EDFDEL = Number of time increments for root growth
For the first time increment, there were not roots in the soil profile.
At the end of this time increment, a root distribution profile was
calculated by scaling the mature root distribution profile to fit a
smaller depth. This depth was calculated under the assumption that the
root profile length versus time can be plotted as a sigmoid curve.
Yield Estijnfttion - This modification was added to the model to estimate
the effect of various irrigation management manipulations on yield.
The salinity effects on yield were sensed only in the root extraction
part of the model where water was taken up in response to a water
potential gradient. The water potential gradient (WPG) was defined as
HROOT. - Ch. + S.)
WPG> * i L_ [8]
i Sic
where HROOT. was the effective root water potential, h^ was the soil
w.ater matric potential and S. was the soil solution osmotic potential
(all at depth z.J. The distance of which the gradient applied, Az, was
assumed to be 1*0. The soil solution concentration was assumed to be
directly proportional to S. according to
S± (millibars) - 36 C.Cmeq/1). [9]
21
-------
The relative yield was assumed to he related to relative transpiration
as
f - f I10'
P P
where Y is the dry matter yield of a given crop for a given season, T
is the transpiration for the same crop for the same season, Y is the
potential yield for the same crop for the same season where sbil water
or salinity did not reduce yield and T is the potential transpiration
for the same crop and season where soiS water uptake was not limited
and thus did not reduce yield. The values of T and T were summed up
over the season to give one seasonal value for each quantity. T was
also given by the input boundary conditions where transpiration was
always equal to potential transpiration.
Input parameters were:
1. ESTART - the number of days from the start of computer
simulation to seedling emergence.
2. ESTOP - the number of days from the start of computer
simulation to maximum effective cover development
3. AIL = ratio of transpiration to evapotranspiration at
maximum effective cover development.
These modifications were built into the computer program so that
adjustments could be made from one crop to another through input
conditions. Otherwise the input data were the same as given by Nimah
and Hanks (1973a, 1973b).
This yield estimation modification, including the background of equation
[10], is very complicated as discussed by Hanks (1974). However, it
seems to give good results.
Transpiration/Evapotranspiration - This modification was used to allow
for variations in the relative proportion of T /ET over the course of
the season. The model of Nimah and Hanks (1973b) allowed for this
proportion to change but because alfalfa was the crop tested T /ET
was assumed to be constant of 0.9 throughout.
It was assumed that the ratio of transpiration to evapotranspiration
versus time for annual crops fitted a sigmoid curve. The sigmoid curve
was used to define the relationship between the time of seedling
emergence and the time of no further change in the T /ET ratio.
Knowing maximum T /ET at a given time, transpiration could be
calculated for any time.
In the event of soil-water constraints on evaporation, a higher
proportion of water will be transpired to meet environmental demands.
22
-------
When actual evaporation, E, fell snort of potential, transpiration was
adjusted upward to make up the energy balance difference according to
the following equation
T - (ET - E ) . [1 + CT^- - 1)
p p p Av
E - E
If T , computed from equation [11] plus E was greater than ET , then
T wls taken to be equal to ET minus E.
Daily Evapotranspiration - This modification was made to account for the
normal fluctuation in ET demand during the daylight hours with
essentially zero ET demand at night. The original model assumed
average ET conditions to be constant over periods of several days. In
the absence of detailed information on this variation, a sinusoidal
pattern was assumed. The variation of evapotranspiration rate was
assumed to start at zero at 0800 hrs, reach a maximum at 1400 hrs, and
return to zero at 2000 hrs. Between 2000 hrs and 0800 hrs the next day,
evapotranspiration was assumed to be zero. The field input evapo-
transpiration rates were averages over a given time period so the
program took these averages and reapportioned them for each time
increment of the daily cycle.
NITROGEN MOVEMENT
Commercial Fertilizer Plots
To study the movement of commercial nitrogen fertilizer in response to
water management, crops and plots were established in 1972 as shown in
Table 2 (See also Figure 1). The "high" water table denotes the
submergence of drains 5N and 5M as explained earlier under the heading
"Irrigation Management Practices". The "normal" water table indicates
that no restriction was placed on drain discharge. (See Section IV,
Results, for discussion of the actual water table depths which occurred.)
The area of the plots receiving uniform application of Ca(NOs)2
fertilizer was centered over the drains as indicated by the rectangles
shown in Figure 1. The size of each treated area was 30.5 by 54.9 m
(about 0.17 hectare). Evapotranspiration (ET) was measured by the
lysimeters in plot 3M and was used as a basis for irrigating the plots
at about 1.1 and 1.5 times ET. The details of the times of irrigation
and EC (electrical conductivity) of the Irrigation water are given in
Appendix B. The rate of water application by the sprinkler system was
0.64 cm/hr.
This experiment was repeated in 1973 with some modifications. The
nitrogen fertilization was the same as 1972 except that the fertilizer
used was NtttN03. This was done because of cost (a factor of two) and
23
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Table 2. COMMERCIAL FERTILIZER NITROGEN TREATMENTS ESTABLISHED IN 1972 ON
THE HULLINGER FARM.
Plot
3N
3M
3S
4N
4M
AS
5N
5M
5S
5AN
SAM
5AS
6N
6M
6S
Crop
Alfalfa
ii
ii
it
11
ii
Corn
it
n
ii
it
11
it
it
ii
Water
Table
Normal
it
11
it
ii
n
High
it
Normal
11
n
n
n
it
ii
a
Nitrogen Level
0
0
0
121 Kg/ha (100 Ibs/a)
484 Kg/ha (400 Ibs/a)
242 Kg/ha (220 Ibs/a)
121 Kg/ha (100 Ibs/a)
484 Kg/ha (400 Ibs/a)
484 Kg/ha (400 Ibs/a)
121 Kg/ha (100 Ibs/a)
484 Kg/ha (400 Ibs/a)
121 Kg/ha (100 Ibs/a)
0
0
0
Irrigation
1.1 ET
n
n
tt
n
n
1.5 ET
tf
t
Tf
1.1 ET
it
tt
n
ii
Elemental N applied as
because the 1972 results showed little nitrate moving through the soil
in the alfalfa plots. Since the fertilizer had to be broadcast and not
disced in the alfalfa, as it was in the corn, it was originally thought
that a nitrate fertilizer, Ca(1103)2. was necessary.
The irrigation water applications were not maintained at as high a level
in 1973 as they were in 1972. The irrigation on the corn was decreased
drastically in 1973, compared to 1972, because irrigation on the corn
was applied when the actual soil water levels decreased to a predeter-
mined value.
Because of the delay caused by construction of the drainage system
modification, it was necessary to delay the 1972 planting of corn
until late June. Just prior to planting the corn, the ground was
plowed out of alfalfa after the first crop was cut. Corn was planted
on May 15, 1973.
Two porous ceramic samplers (Soil Moisture Equipment Co., Santa Barbara,
California approximately 4 cm, 1-5/8 in. diameter) were installed to a
depth of about 106 cm in northeast and southwest quarter of each plot
24
-------
in 1972. In 1973 two samplers were installed at each location used in
1972 (four samplers per plot) with one at 76 cm and the other at 106
cm depth. Samples were collected at periodic intervals throughout the
season generally a day or two after irrigation. For sampling, suction
was applied to the sampler with a hand pump. The sample was collected
several hours later by applying suction to the sampling bottle which
was connected to a small tube pushed into the water that had collected
in the bottom of the sampler.
Manure Plots
Forty-eight plots were laid out near the irrigation pond for the dairy
manure studies. The detail of these plots are shown in Figure 3. Plots
were 6.1 by 12.2 m where crops were grown and 6.1 by 6.1 m for the bare
treatments. Rates of manure application in 1972 were 0, 54, 108, and
216 metric tons per hectare (mt/ha) calculated as a dry weight
equivalent (0, 25, 50, and 100 t/a). Irrigation was by sprinkler. The
manure was plowed in immediately after application of the plots. As
shown by Figure 3, half of the cropped plots were planted to corn and
half to sudan grass at the end of June, 1972.
In 1973 all of the cropped plots were planted to corn on May 15. Prior
to planting, the plots that had been in sudan grass the previous year
were retreated with the same amounts of dairy manure as shown in
Figure 3.
Ceramic soil water solution samplers were installed in the middle of
each plot to a depth of 106 cm. These samplers were also used as
access tubes for measuring soil water content with the neutron probe.
Sampling was accomplished in a manner described earlier for the
commercial fertilizer plots.
Barrel Lysimeters
In an effort to have a closed system where uncertainties regarding
upward water flow were eliminated, barrel lysimeters were installed
as shown in Figure 1 near the manure plots. The barrels received the
same amount of irrigation water as the manure plots. Ceramic samplers
were installed in the barrels for solution sampling and soil moisture
measurement as described earlier.
Twenty-four barrel lysimeters were installed in 1972. An essentially
undisturbed core of soil was removed from the field and placed in a
55-gallon drum. The filled drum was then lowered into the hole.
Treatments; applied to the barrels are shown in Table 3. These treat-
ments were applied in 1972 only.
Barrels 5, 6, 7 and 8 were scheduled to receive a high rate of water
application throughout the season in 1972 while the remaining barrels
were scheduled to receive a normal application of irrigation water.
25
-------
A 1
108
mt/ha
CORN
A2
216
mt/ha
CORN
A3
0
mt/ha
BARE
A4
54
mt/ha
CORN
A5
0
CORN
A6
108
mt/ ha
CORN
Bl
0
CORN
B2
54
mt/ha
CORN
B3
54
mt / ha
BARE
B4
108
mt / ha
CORN
B5
216
mt/ha
CORN
B6
54
mt/ha
CORN
CI
216
mt/ha
CORN
C2
108
mt/ ha
CORN
C 3
108
mt /ha
BARE
C4
0
CORN
C5
54
mt/ha
CORN
C6
0
CORN
Dl
54
mt/ha
CORN
D 2
0
CORN
D 3
216
mt/ha
BARE
D4
216
mt/ha
CORN
D5
108
mt/ha
CORN
06
216
mt/ ha
CORN
El
0
SUDAN
GRASS
E2
216
mt/ha
SUDAN
GRASS
E 3
0
BARE
E4
108
mt/ha
SUDAN
GRASS
E5
0
SUDAN
GRASS
E6
54
mt/ha
SUDAN
GRASS
Fl
108
mt/ha
SUDAN
GRASS
F 2
54
mt/ ha
SUDAN
GRASS
F 3
54
mt/ha
BARE
F4
0
SUDAN
GRASS
F5
216
mt /ha
SUDAN
GRASS
F6
108
mt /ha
SUDAN
GRASS
G 1
216
mt/ha
SUDAN
GRASS
G 2
108
mt/ ha
SUDAN
GRASS
G 3
108
mt/ha
BARE
G4
216
mt / ho
SUDAN
GRASS
G5
54
mt/ ha
SUDAN
GRASS
G6
0
SUDAN
GRASS
H 1
54
mt/ha
SUDAN
GRASS
H2
0
mt/ha
SUDAN
GRASS
H 3
216
mt/ha
BARE
H4
54
mt/ha
SUDAN
GRASS
H5
108
mt / ha
SUDAN
GRASS
H6
216
mt / ha
SUDAN
GRASS
N
Figure 3. Manure plot layout on Hullinger farm.
26
-------
Table 3. FERTILIZER TREATMENTS APPLIED TO BARREL LYSIMETERS IN 1972,
Barrel No. Treatments
1, 4 440 Kg/ha N as Ca(N03)2
2, 3 216 mt/ha manure
5, 8 110 kg/ha N as Ca(N03)2
6, 7 440 kg/ha N as Ca(N03)2
9, 12 440 kg/ha N as Ca(N03)2
10, 11 110 kg/ha N as Ca(N03)2
13, 19, 22 108 mt/ha manure
16, 20, 23 No application - Check
15, 18, 24 54 mt/ha manure
14, 17, 21 216 mt/ha manure
Barrels 1, 2, 3, and 4 had drain cans installed so that any free water
existing at th.e bottom, of the barrel would drain out of the soil into
the drain can from which a sample could be removed. In the other
barrels, free water would remain in the soil. However, the amount of
water applied in 1972 was so great that all of the barrels without
drains were waterlogged throughout most of the year. Consequently
in 1973 drains were installed in all of the barrels and no water-
logging occurred. Corn was planted in the barrels in both years at
the same time the manure plots were planted.
Sample Analysis
Soil sampling of the manure and nitrogen fertilizer plots was done in
the fall and spring. These samples were put in a room at 0° C until
the chemical analyses for nitraces and EC could be made. EC was
determined on the saturated paste extract before nitrate analysis.
27
-------
Nitrate content was determined for soil, plant, and water samples
using the pheixoldisulfonic acid method (Bremner, 1965) and modified
to eliminate chloride interference by using 0.02 N copper sulfate
0.002 N silver sulfate extract-in-solution in a 5/1 ratio of solution
to soil. Conductivity was determined with a pipette conductivity cell.
Total N was determined by micro Kjeldahl.
Vegetation samples were collected, dried and analyzed by the same
procedures used for soils. Only leaves near the ear were selected
for corn samples.
28
-------
SECTION V
RESULTS AND DISCUSSION
GENERAL
Results common to both salt and nitrogen movement studies are given
before results specific to each.
Evapotranspiration and Climate
Lysimeter evapotranspiration and climatic data are shown in detail in
Appendix B (Tables B-l and B-2). The data indicate that the ET from
the lysimeters was about 62 cm in 1972 (from June 24 through September).
Sufficient data was collected so that the potential evaporation from
a free water surface could be computed by the Penman equation with two
modifications described by Wright and Jensen (1972). Figure 4 shows
that the lysimeter cumulative evapotranspiration is about 19 cm greater
than the potential evaporation as computed by the Penman equation.
There was very little difference between the two modifications of the
Penman equation. Thus it is apparent that the potential evaporation
as computed by the Penman equation does not have the expected simple
relation to the measured evapotranspiration. It was expected that the
ratio of measured ET to Penman E would vary from about 0.8 to 1.1
during the season. This result is similar to that measured in 1971
[King and Hanks, (1973)].
Irrigation
Details of irrigations applied to the Hullinger Farm for 1972 and 1973
are given in Appendix B (Tables B-3 and B-4). Also shown are the date
and the depth and electrical conductivity of water applied for each
irrigation.
The irrigation data are summarized in Table 4. While the average EC
values of Table 4 are grouped around 1.0 mmho/cm the range of values
for individual irrigations was 0.8 to 1.6 mmho/cm for 1972 and 0.6 to
1.5 mmho/cm for 1973.
Drainage Discharge.
The discharge pf water from ea,ch tile drain was measured daily over a
short time interval (essentially an instantaneous measurement). All
discharge measurements are reported in Appendix B (Tables B-5 and B-6).
The drain discharge data are summarized as cumulative drainage in
Table 5.
29
-------
PENMANS
f(u)= 1.0 + O.Olu
10 20
AU6
10 20
SEPT
Figure 4. Cumulative evapotranspiration measured by lysimeters
compared with potential evaporation computed with
Penman's equation for 1972.
30
-------
Table 4. TOTAL IRRIGATION WATER APPLIED, NUMBER OF IRRIGATIONS, AND
AVERAGE EC OF IRRIGATION WATER ON HULLINGER FARM.
Block a Plot a
1
1
2
3
4
5
6
7
8
8
9
Crop
Total Water
Applied
(cm)
-1972-
Corn 68.
Alfalfa 55.
IN,
2N,
3N,
4N,
5N,
SAN
5AM,
6N,
1M,
2M,
3M,
4M,
5M,
5AS
6M,
IS
2S
3S
4S
5S
6S
Alfalfa
Alfalfa
Alfalfa
Alfalfa
Alfalfa
Corn
Corn
Corn
Corn and
Sudan Grass
89.
73.
66.
63.
65.
83.
87.
72.
74.
8
4
3
3
9
9
3
1
2
3
1
Number of
Irrigations
12
8
11
19
13
9
12
15
14
14
14
Average
EC
(roinho/cni)
1
1
1
1
1
1
0
1
1
1
1
.2
.1
.1
.1
.1
.0
.9
.1
.1
.1
.1
-1973-
1
1
2
3
3
4
4
5
5
6
7
8
9 *j
9
IN
m, is
2N
2M, 2S
3N
3M, 3S
4N, 4M, 4S
5N, 5M, 5S
SAN, SAM,
5AS
6N, 6M, 6S
Corn
Alfalfa
Alfalfa
Alfalfa
Alfalfa
Alfalfa
Alfalfa
Alfalfa
Alfalfa
Alfalfa
Corn
Corn
Corn
Corn
35.2
34.5
56.4
83.2
52.8
84.5
54.1
.83.6
53.2
53.0
30.9
31.1
32.6
35.2
8
6
7
10
8
9
7
9
7
7
6
6
6
8
1.0
0.9
1.0
1.0
1.0
1.0
1.0
1.1
1.1
1.0
0.9
0.9
1.0
1.0
frhe block and plot designations are given in Figure 1.
EC of each irrigation weighted by amount of water applied. Irrigations
for which EC data were not available were ignored in computing average
EC.
East part.
West part.
31
-------
Table 5. CUMULATIVE DRAINAGE IN 1972 (STARTING 6-28) AND 1973
(STARTING 6-18).
(m3)
Plota
3N
4N
AM
4S
5N
5M
5S
SAN
SAM
5AS
6N
6M
6S
IN
1M
2N
2M
3N
3M
4N
4M
5N
5M
SAN
SAM
6N
6M
6-30
21
32
4
0
26
5
0
3
1
0
1
0
0
72
7
185
24
424
34
363
216
365
41
48
27
228
34
7-15
38
246
21
0
670
130
0
114
60
0
285
73
0
72
8
217
25
633
34
500
263
585
43
80
48
386
68
Date
7-30
-1972-
38
492
94
0
1199
276
40
227
145
42
590
228
18
-1973-
261
8
546
25
1446
35
1325
633
1534
168
196
116
1004
220
8-15
178
1005
375
35
1864
492
264
364
261
140
790
319
44
264
9
577
25
1864
47
1997
937
2375
268
318
157
1575
305
8-30
200
1280
571
46
2315
636
300
438
303
140
1030
348
44
294
9
729
26
2707
77
3243
1434
3701
435
617
231
2815
575
9-15
229
1576
761
46
2667
696
300
477
333
140
1081
354
44
363
9
1092
26
3714
112
4318
1846
4646
492
627
270
3367
657
Depth
cm
5
34
16
1
57
15
6
10
7
3
23
8
1
8
0
24
1
80
2
93
40
100
11
13
6
72
14
not included in list, had no discharge from drain.
Cumulative on 9-15 assuming a plot size of 76 x 61 m (250 x 200 feet) .
32
-------
The data of Table 5 show that by July 1972 some of the south drains
had discharged water while in 1973 none of the south drains had had
any discharge. These differences in discharge from the south drains
can be explained by the differences in irrigation water applied.
Table 4 shows that the plots overlying all south drains received more
water in 1972 than in 1973. In 1972, plots 5S, 5AS, and 6S received
more than twice the irrigation water applied to these plots in 1973.
All north drains had more discharge in 1973 than in 1972 as did the
middle drains except 5M and SAM. Even for drains IN, 2N, and 3N the
extra irrigations on June 19 and June 25, 1973 cannot explain the
greater discharge because these effects should have been dissipated
within a week or two, but the discharge of drains IN, 2N, and 3N
increased significantly on into August and September. Except for
plots IN, 2N, and 3N, all plots received more irrigation water in
1972 than 1973. Note also that drain 5N discharged almost twice the
water in 1973 as in 1972 and the 1973 discharge for drain 6N was
about 3 times the 1972 discharge (Table 5). The 1972 irrigation
water applied to plots 5N and 6N was more than twice the 1973 appli-
cations. For 1973, drain 5N discharged about 3 times the water
applied as irrigation to plot 5N (assuming a plot size of 76 x 61 m)
and drain 6N discharged more than twice the water applied.
The above discussion leads to the conclusion that drain discharge
was significantly affected by factors other than water management
practices on the farm itself. This conclusion is also supported
by an analysis of water table requirements.
Much of the water discharged by the drains must have originated outside
the farm boundary, which will be discussed later. Any control over
salt movement in the root zone may be masked by groundwater flow
conditions unless the control area is large enough to influence the
groundwater basin. Thus it is apparent that a single farmer or small
group of farmers cannot hope to significantly influence the quality
of irrigation return flow. Control programs must be large enough to
encompass hydrologic units.
Water Table Depth.
Water table depth was measured at approximately weekly intervals at
all the piezometer locations shown in Figure 1. Results from
selected piezometers are included in this report. Locations of these
piezometers are given in Table 6. The locations identified with
numbers 1 through, 14 are included inainly to determine groundwater
hydraulic head gradients which are discussed in a following section
under the heading "Groundwater Movements." The piezometers numbered
15 through 28 (Table 6) are included to show the water table depths
under field plots. Table 7 gives the piezometer identification
number, the field plot and the average water table depths for 1972
and 1973. In all cases the average depth to water table was less in
33
-------
Table 6. PIEZOMETER IDENTIFICATION NUMBER.
Location3 Ident. No. Location3 Ident. No.
Location3 Ident. No.
1W100N50
1W100N4
1W100-20
3W5N47
3W5N4
3W5-20
3W100N43
3W100-20
5AE25N50
5AE25N12
1
2
3
4
5
6
7
8
9
10
5AE25-20
6W5N50
6W5N12
6W5-20
3W5-150
4W5-150
5W5-150
5AW5-150
6W5-150
11
12
13
14
15
16
17
18
19
4W5-400
5W5-400
5AW5-400
6W5-400
4W5-650
5W5-655
5AW5-650
6W5-650
6W149-400
20
21
22
23
24
25
26
27
28
The location of piezometer shown on Figure 1 is designated by a
coordinate system referenced to the drains and to the north boundary
fence of the form. Thus, "1W100N50" means 100 ft. west of drain 1 and
50 ft. north of the fence. For locations south of the fence, "-" is used
in place of "N".
1973 than in 1972. While these piezometers are only 1.5 m from the
drains, studies of drain performance on the Hullinger farm (Sabti,
1974) show that most of the water table drop occurs closer to the
drains and that piezometers 1.5 m from the drains give essentially the
same water table depth as those farther from the drains. The water
table tends toward a plane between drains with most of the lowering of
the water table occurring very close to the drains. All measurements
of water table depth for the selected piezometers (Table 6) are shown
in Appendix B (Tables B-7 and B-8).
Groundwater Movements
As discussed above, much, of the water discharged by the drains came
from groundw^ater movwig from outside the boundaries, of the Eullinger
farm. The water table depth, from piezometers 1 through 14 (Table 6}
may be used to determine the tendency for ground water encroachment
from the north. Groups of these piezometers form north-south lines
over which the hydraulic head gradients can be calculated. Five north-
south lines are represented by the following piezometer groups: 1, 2,
3; 4, 5, 6; 7, 8; 9, 10, 11; 12, 13, 14. The water table depth
34
-------
Table 7. AVERAGE WATER TABLE DEPTH DURING IRRIGATION SEASON UNDER
FIELD PLOTS ON THE HULLINGER FARM.
Average Water Table Depth (m)
Identification No.
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Plot
3N
4N
5N
5AN
6N
4M
5M
5AM
6M
4S
5S
5AS
6S*
a
Manure Plots
1972
1.59
1.18
1.08
1.31
1.58
1.36
1.34
1.32
1.47
1.87
1.78
1.80
2.16
1.66
1973
1.43
1.13
1.03
1.23
1.48
1.30
1.30
1.24
1.39
1.83
1.77
1.78
2.07
1.47
aPiezometers 27 and 28 may be used to estimate the water table
depth beneath the manure plots.
measurements were used to calculate water table elevation above mean
sea level (Tables B-7 and B-8). A survey of water table elevation for
these groups of piezometers shows that whenever there were differences,
the gradient w.as such that th_e groundwater flowed toward the south.
That there is a southerly component to groundwater flow under the plots
is indicated by the water table elevations, for instance for piezometers
16, 2Q, and 24, the main ground water flow is from west to east.
35
-------
SALT MOVEMENT
Field Studies
Irrigation Management - Irrigation of the large plots during 1972 was
scheduled as indicated in Figure 1 where ET denotes the evapo-
transpiration of alfalfa as measured by the lysimeters in plot 3M,
These irrigation amounts were scheduled to insure that nitrogen would
move downward through the soil. Earlier experience (King and Hanks,
1973) on the Hullinger farm indicated that significant upward flow of
water from the water table to the root zone could occur. The irri-
gation for 1972 was planned in an attempt to minimize this effect.
In 1973 the corn was irrigated whenever the soil moisture decreased
to a predetermined level resulting in much lower total water application
than in 1972.
Effects of irrigation management on salt movement was studied by EC
measurements of drain water and water samples collected from ceramic
cups placed in the soil above the water table. Each time the drain
discharge was measured, a sample of the effluent was collected and EC
measurements made. Electrical conductivity (EC) of these samples
is given in Appendix B (Tables B-9 and B-10). Using the EC data of
Tables B-9 and B-10 and the drain discharge data of Tables B-5 and
B-6, the cumulative mass of salt removed by the drains was calculated
and is presented in Table 8. Table 8 shows that although the average
EC for any drain was essentially the same for 1972 and 1973, the total
salt discharged was greater for 1973. Since the EC of irrigation
water was also essentially the same for these two years, the greater
salt discharge was caused directly by greater drain flow.
In general, the high EC values of drain effluent are associated with
drains having low flows. The average EC (Table 8) increases
progressively from north to south (for example, plots 6N, 6M, and 6S
for 1972). Thus, evidence exists indicating salt storage in zones
above the water table. This storage has probably been going on for
a long time and is probably not directly a result of irrigation
management practiced since research, began on the Hullinger farm.
Note from Table 7 that water table depths also increase from north
to south. This is the result of natural groundwater hydrology for
this area. In 1970 and 1971, before the drains were divided, the
single drain 3 was observed to flow only once as a result of the
discharge of water directly over the drain from a disconnected
irrigation pipe. In 1972 and 1973, after drain division, drain 3S
never flowed while drain 3N flowed significantly. Thus it is apparent
in 1970 and 1971, water entered the north part of drain 3 and seeped
back into the groundwater in the south part before reaching the
measuring manhole.
36
-------
Table 8. CUMULATIVE SALT FLOW FROM THE DRAINS IN 1972 (STARTING
6-28) AND 1973 (STARTING 6-18).
(kg)
Plot
3N
4N
4M
AS
5N
5M
5S
SAN
SAM
5AS
6N
6M
6S
IN
1M
2N
2M
3N
3M
4N
4M
5N
5M
SAN
SAM
6N
6M
6-30
27
28
5
0
26
5
0
3
1
0
2
0
0
111
13
295
39
512
42
400
303
460
61
69
47
248
55
7-15
47
210
30
0
602
126
0
100
46
0
353
73
0
112
14
348
39
769
42
544
374
732
64
115
85
423
106
7-30
47
428
120
0
1129
287
38
187
111
54
675
279
11
403
15
821
40
1711
43
1444
920
1885
248
271
194
1102
327
Date
8-15
-1972-
220
904
488
60
1838
550
215
282
191
185
855
394
72
-1973-
449
15
863
41
2155
61
2128
1348
2771
372
425
257
1704
445
8-30
254
1200
773
80
2410
775
239
327
217
184 '
1042
443
72
455
16
1087
41
3111
103
3428
2046
4162
588
652
366
3001
795
9-15
300
1498
1056
80
2872
867
239
351
235
184
1081
453
72
567
17
1603
42
4267
154
4556
2642
5167
657
780
420
3623
899
EC AVE
mmho/cm
2.1
1.5
2.2
2.7
1.8
2.0
2.2
2.3
2.3
2.2
1.8
2.2
2.9
2.5
3.6
2.4
3.4
1.8
2.3
1.7
2.2
1.8
2.1
2.0
2.5
1.7
2.2
37
-------
Tables B-9 and B-1Q show that the EC of drain effluent ranged from
1.1 to 3.7 nmiho/cm. For drains for which 5 or more samples were taken,
i.e., drains observed to flow on 5 or more days, the range was 1.1 to
3.3 mmho/cm.
Table B-9 shows a general increase in EC as the 1972 season progressed.
For 1973, this trend was reversed as shown in Table B-10. This trend
could have been influenced by differences in amounts of irrigation
water applied to the Hullinger farm for these two seasons. However,
such effects are probably masked by the groundwater movement from
outside farm boundaries.
Electrical conductivity measurements on water samples withdrawn from
the ceramic cups in the soil above the water table are given in
Appendix B (Tables B-ll and B-12). Table 9 compares the EC values
from the ceramic cups with those from the drains under the various
plots. The average EC of water from the ceramic cups was always
greater than the EC of the drain effluent, in many cases nearly twice
as great. This fact further demonstrates the inflow of groundwater
to the drains from areas outside the farm boundaries. Since the
neighboring farmers have historically used flood irrigation methods
applying excess water, the water draining from their fields comes
through well leached sites. Thus the intruding groundwater tends to
dilute the water percolated through the root zone on the Hullinger
farm causing the drain effluent to register a lower EC relative to the
percolated water.
The above results indicate that although water table depth may be an
important factor in managing irrigation for salinity control of return
flow, the total seasonal salt discharge was directly related to the
quantity of water discharged because there was little change in EC of
the drainage water with time. This emphasizes again that management of
water is the key to successful return flow quality management. This
is true for much of the Upper Colorado River Basin where the concen-
tration of salts in return flow is not too great. It is especially
true for soil situations like that of the Hullinger farm where there
are large salt source and sink components to flow (discussed in more
detail in the following sections). Any control plan which will reduce
total discharge of water will probably also reduce total discharge of
salts, at least over the short term.
Field Trial 1 - This trial involved putting salty water that had been
concentrated in the evaporation pond onto the test plot and measuring
the resulting change in soil solution concentrations with time and
depth. Two methods, of measuring concentration were used - soil water
extraction with, ceramic samplers and four probe conductivity measure-
ments. Data from the ceramic samplers had the disadvantage that it
took several hours of applied suction to get a sample sufficient for
measurement. The four-probe conductivity method has the disadvantage
of being influenced by soil water content as well as solution
38
-------
Table 9. SUMMARY OF THE ELECTRICAL CONDUCTIVITY OF WATER
COLLECTED FROM CERAMIC CUPS AT 106 cm DEPTH AND
FROM THE DRAINS OF VARIOUS PLOTS.
(mmho/cm)
Plot
3N
3N
3M
3M
3S
3S
4N
4N
4M
4M
4S
4S
5N
5N
5M
5M
5S
5S
SAN
SAN
SAM
SAM
5AS
5AS
6N
6N
6M
6M
68
6S
Sample
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Cups
Drain
Low
2.6
1.6
2.9
4.1
1.5
1.1
2.3
1.4
3.3
2.2
2.4
1.2
1.2
1.2
3.1
1.7
0.9
1.3
2.4
1.8
2.4
1.9
1.9
1.2
2.0
1.5
1.7
2.8
1972
High
5.0
2.6
4.6
7.7
5.4
1.9
4.5
2.7
7.5
3.1
4.7
2.4
4.4
2.7
4.8
2.4
3.7
3.0
4.5
3.0
4.0
2.4
3.9
2.7
3.5
3.3
4.8
3.0
Ave.
3.8
2.1
3.9
a
5.8
a
2.9
1.5
3.5
2.2
4.5
2.7
3.7
1.8
3.3
2.0
3.9
2.2
2.8
2.3
3.7
2.3
3.5
2.2
3.0
1.8
2.5
2.2
3.5
2.9
Low
1.5
1.3
2.1
2.5
1.5
1.8
1.7
3.5
1.5
2.7
1.8
1.9
1.6
1.8
2.1
2.3
1.4
2.3
1.9
1973
High
2.1
4.1
2.4
4.4
1.8
4.8
2.5
4.1
2.1
4.0
2.8
4.3
2.3
3.9
2.9
5.1
2.0
4.3
2.7
Ave.
b
1.8
2.7
2.3
b
a
3.8
1.7
3.5
2.2
b
a
3.8
1.8
3.0
2.1
b
a
3.0
2.0
2.9
2.5
b
a
3.5
1.7
3.2
2.2
b
a
No flow.
No data.
39
-------
conductivity but it has the advantage of allowing rapid reading and
many measurements. For the analysis of data, the four probe measure-
ments were first corrected for water content by the use of a calibra-
tion equation similar to that suggested by Gupta and Hanks ( 1972) and
were then adjusted by a constant factor to get values corresponding
to the approximate EC readings from the ceramic cup water samples.
The end result comparing the adjusted four-probe conductivity readings
with the ceramic cup samplers is shown in Figure 5. The "raw" data
adjusted only for water content are shown in Appendix B (Table B-13).
As shown in Figure 5, the agreement between the measured and four-probe
conductivities are fairly good before the salty water was added but not
as good at the end of the trial.
Figures 6 and 7 show the four-probe estimated conductivity profiles
at several times. The data show an increase of EC between the soil
surface and about the 45 cm depth after wetting with 10 cm of water
at EC of 8.0 mmho/cm and a decrease at deeper depths. Assuming simple
piston flow the "salty" water should have penetrated to about 30 cm
and the before wetting peak, located at about 60 cm, should have
shifted down by about 30 cm. Shifting of the lower peak did not
occur. When another addition of 10 cm of water, EC of 4.1 mmho/cm
was added there was relatively little change in the salt profile as
shown in Figure 6. The addition of water less salty than the solution
concentration did not decrease the EC near the soil surface. The data
indicate that the addition of large amounts of water at the soil
surface had little effect on the soil solution EC in the profile. This
same conclusion was born out by the data collected from the ceramic
cups.
Field Trial 2 - The September 1972 trial, which was conducted similarly
to the August trial but with different EC in the applied water, gave
results which led to conclusions similar to the August trial (Figure
7). Wetting with water of EC 4.7 mmho/cm should have caused a
depression in EC, if simple piston flow occurred, whereas an increase
in surface EC resulted. When the less salty water of EC 1.1 mmho/cm
was applied the next day, some depression in EC resulted but it was
not nearly as great as expected. The data showed a rather large shift
towards lower EC for the entire profile immediately after wetting.
However, the profile had shifted back towards higher EC values 35
minutes later. A further shift towards higher EC values was measured
in the lower profile a day later. The results of this run indicate
the presence of a large "buffering" capacity within the soil.
Observed response to water applied can be explained only if consider-
able precipitation and solution is taking place.
Field Trial 3 - This trial was run at the Hullinger Fajnn in 1973 where
better control pn the amount of water applied was attained. In this
trial intensive soil sampling was done and the EC determined pn 1:5
soil water extracts. The results of the first run, given in Table 10
40
-------
E
o
£L
U
O
E
o
0
20
40-
60
80-
100
120-
140
160-
180
200
8
10
12
20
4O
60
80
100
120
I-
g 140
160
180
200
FROM 4 PROBE
ESTIMATE
CERAMIC CUP
SAMPLES
8-11-0835
FROM 4 PROBE
ESTIMATE
CERAMIC CUP
SAMPLES
8-9-72 07OO
BEFORE ADDING
WATER
2 4 6 8 10 12
WATER CONCENTRATION, mmhos/cm
Figure 5. Comparison of electrical conductivity measured from
samples taken from ceramic samplers with 4-probe
corrected values.
41
-------
E
u
»
X
I-
0.
UJ
o
E
u
0
40
80
120
160
200
0
40
80
120
& I6°
o
200
8 9
8-9 0700
ABOUT 4 INCHES OF WATER
ADDED ECWATER =
8.0 m mho/cm
8-9 0935
8-9 1655
t;
ABOUT 10 INCHES OF WATER
ADDED 8-10 0745
EC WATER = 4.1 mmho/cnv,
8-10
0730
8-10 08KH*
8-11 0835
I
234567
SOIL SOLUTION EC-mmho/cm
8 9
Figure 6. Soil solution electrical conductivity (mmhos/cm) as mea-
sured by the 4-probe horizontal probe before and after
water application - field trial 1.
42
-------
E
o
*
X
I-
0.
40
80
120
160
200
40-
80
o 120
UJ
o
160
200
"I 1
9H9 I04O
ABOUT 3 INCHES OF WATER
ADDED 9-19 1130
9-19 1150
9-20 1100
ABOUT 4 INCHES OF
WATER ADDED 9-20 1300
lE^WATER" I.Immho/cm
9-20 1345
9-20
1420
9-21 1325
J L
J L
2345678
SOIL SOLUTION EC-mmho/cm
Figure 7. Soil solution electrical conductivity (mmhos/cm) as measured
by the 4-probe horizontal probe before and after water
application - field trial 2.
43
-------
Table 10. WATER CONTENT, 1:5 ELECTRICAL CONDUCTIVITY, AND 4 PROBE
CONDUCTIVITY (VERTICAL 4-PROBE) FOR FIELD TRIAL 3 FIRST RUN.
Vernal, June 30-21, 1973
Soil Water Content
Depth Volume Fraction
cm A B C D
30
46
61
76
91
107
122
A -
B -
.23
.27
.27
.26
.23
.26
.30
Readings
.28 .26
.31 .27
.31 .29
.31 .29
.24 ,26
.28 .27
.30 .29
taken at
.28
.30
.30
.30
.33
.28
.28
4-probe conductivity
mmho/cm
A B C D
1.9
3.8
3.7
4.2
2.1
2.7
2.8
beginning of
Readings taken after irrigating
3.6
5,4
4.9
5,8
3.2
2.9
3.0
test
with
3.5
4,8
5.5
6.4
3.4
3.2
2.9
3.3
4.9
5,8
5.2
2.8
2.8
3.2
about 25
1:5
A
.20
.18
.18
.25
.26
.25
.27
cm of
conductivity
mmho/cm
BCD
.17
.20
.18
.18
.25
.25
.26
water,
.20
.26
.25
.30
.29
.21
.23
.20
.20
.25
.26
.28
-
EC = 1.5 mmho/cm.
C - Readings taken after irrigating with about 5 cm of water,
EC = 10.0 mmho/cm.
D = Readings taken after irrigating with about 5 cm of water,
EC = 1.5 mmho/cm.
show that the effect of water content on the 4-probe EC results of
treatments B, C, and D should be small since the water contents were
essentially constant. The 1:5 conductivity was only slightly higher
for treatment C, where salty water had been added, than other treat-
ments. If piston flow occurred, the salty water of treatment C should
have been in the top 20 cm and in the 20 to 41 cm zone for treatment D,
The data do not Indicate this to be the case. This would indicate
that the salty water being added to the soil was taken out of solution
by some means and does not contribute to the conductivity. The
increase in four-probe conductivity above 76 cm between treatment A
and B was probably due to the water content increase.
Two sets of ceramic extraction cups were installed at various depths
prior to the second run. The data, shown in Table 11, indicate an
increase in conductivity as measured by the ceramic samplers for
treatment B over treatment A as would be expected. If piston flow
occurred, the conductivity down to 46 cm should have been about
1Q mmho/cm. The data indicate an. actual EC of only 4.6 to 9.5,
which is lower than expected. However, the 1:5 EC from the soil
samples showed an increase in EC above 60 cm from A to B but again
it was less than expected. The increase should have been a factor
of 3 to 4 but it was less than two. When water of EC = 1.0 mmho/cm
44
-------
Table 11. COMPARISON OF ELECTRICAL CONDUCTIVITY, EC, OF SAMPLES
EXTRACTED FROM CERAMIC SAMPLERS WITH 1:5 SOIL SOLUTION
EXTRACTS. VERNAL, UTAH, AUG. 9-10, 1973 FOR FIELD
TRIAL 3 SECOND RUN.
(iranho/cm)
Depth
EC from ceramic samplers
EC from soil
samples
15 cm
30 cm
46 cm
61 cm
76 cm
91 cm
107 cm
122 cm
137 cm
152 cm
168 cm
AS AN BS BN
2.0 9.5
1.9 3.2 6.9 4.6
2.2 7.4
3.1 4.0
4.6
4.4 2.6
2.0
CS CN
3.6
1.3 5.0
7.0
2.5 5.3
3.2
4.1 3.4
1.9
C LAB
4.2
4.5
-
4.5
3.1
2.9
1.9
A
.25
.23
.22
.22
.25
.24
.22
.21
.22
.17
.19
B
.43
.35
.34
.28
.35
.26
.25
.22
.21
-
"""
C
.30
.32
.30
.36
.35
.36
.34
.30
.32
.25
"
A - Sample collected after irrigation with about 10 cm water, EC
1.0 mmho/cm
B - Sample collected after irrigation with about 10 cm water, EC
10.0 mmho/cm
C - Sample collected after irrigation with about 10 cm water, EC
1.0 mmho/cm
S = South sampling site
N = North sampling site
C LAB is data measured by USU Soil Test Lab collected from the "C"
treatment.
45
-------
was added, treatment C, the ceramic sampler data showed no pronounced
shift of the salt peak to a depth of about 46 cm as would be
predicted assuming piston flow although there was a decrease in the
EC near the surface. The decrease of EC near the surface was less
than predicted which is a further indication that solution- and
precipitation-like processes are occurring. The EC of the soil
samples did increase below 61 cm and decreased only slightly above
that depth from treatment B to C as would be expected. Rere again,
however, the changes are much smaller than would be expected if no
solution, precipitation or exchange occurred.
Because it was apparent that some complex chemical changes were
occurring, soil and water samples were collected and brought back to
the USU Soil Test Lab for more detailed analysis. These data are
shown in Table 12. The data indicate that the NaCl water moved almost
to 152 cm. The Na concentration before treatment is believed to be
about 4 meq/liter. The NaCl water was certainly not "washed" out of
the top 46 cm as would be expected if simple piston flow occurred.
The data also account for only about 35% of the Na applied (using the
soil extraction data). The question remains as to the disposition of
the sodium. The 1:100 dilution data indicate that diluting the soil
with an excess of water does not bring any more total Na into solution
although large amounts of Ca and Mg appear to have come into solution.
To determine whether the EC was lower than expected because of ion pair
formation, a calculation of theoretical EC from the chemical data of
Table 12 was made by the method of Griffin and Jurinak (1973). If
ion pair formation were a factor, the calculation of EC, assuming no
ion pairs, would have b&en lower than that measured. The data show
the calculated and measured EC to be the same, so there does not appear
to be ion pair formation.
The horizontal four probe measurements made in the field during the
second run are shown in Table 13. The increase in EC near the
surface, from 1032 to 1440 on August 8, was probably due to increased
water content caused by the addition of normal pond water. A further
increase from an EC of 53 mmho/cm averaged over the top 61 cm to about
80 mmho/cm, occurred when the salty water was added at 1300 hours on
August 9. The further addition of 10 cm of "normal" water caused the
average EC of the top 46 cm to decrease from about 76 to 60 mmho. In
the 46 to 91 cm depth, the EC increased from 59 to 78 cm due to the
last water addition. The average conductivity from 91 to 183 cm yaried
from 58 to 59 mmho after the first addition of water until the last
reading. Thus it is concluded that the data of the. horizontal four-
probe agree in general with, the sample data of EC by the. two other
sampling procedures used.
Field Trial 4 - Study of salt and water flow was made on Kidman silt
loam at the USU Farmington Experiment Station. Water in this trial
was added by trickle irrigation, as described in the methods section,
46
-------
Table 12. CHEMICAL ANALYSIS OF SOIL SOLUTION (FROM SATURATION EXTRACT)
AND WATER SAMPLES. AUGUST 10, 1973. ANALYSES BY USU SOIL
TEST LAB.
Sample Description
me /liter
ph Ca
Pond Water (normal)
Salty Water (NaCl)
Pond Water (normal)
Extractor 15 cm
Extractor 30 cm
Extractor 46 cm
Extractor 61 cm
Extractor 76 cm
Extractor 91 cm
Soil 0-15 Sat. Ext.
Soil 15-30 Sat. Ext.
Soil 30-46 Sat. Ext.
Soil 46-61 Sat. Ext.
Soil 61-76 Sat. Ext.
Soil 76-91 Sat. Ext.
Soil 91-107 "
Soil 107-122 " "
Soil 122-137 " "
Soil 137-152 " "
Soil 0-15 1:100 Ext.
Soil 15-30 " "
Soil 30-46 "
Soil 18-24 "
Soil 61-76 "
Soil 76-91 " "
Soil 91-107 "
Soil 107-122"
Soil 122-137"
Soil 137-152"
EC is the calculated
(A)
(B)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
(C)
8.4 7
7.6 8
8.3 9
8.0 9
7.9 23
8.0 23
7.8 16
8.2 17
8.2 12
- 12
- 11
- 12
- 12
- 10
9
- 12
- 12
- 15
- 14
_
-
1
1
1
-
-
-
-
.6
.8
.0
.4
.1
.8
.3
.0
.5
.7
.9
.8
.3
.7
.1
.2
.3
.0
.0
.60
.66
.09
.33
.06
.89
.90
.80
.83
.82
conductivity
Mg
3.9
4.3
4.2
4.5
10.3
13.3
8.1
7.8
7.0
5.1
4.8
5.7
6.0
5.2
4.1
5.2
5.6
7.4
6.3
.20
.20
.28
.38
.34
.29
.26
.24
.24
.24
as EC1
Na
0.7
87.0
0.8
28.7
12.2
6.5
6.5
2.6
1.7
9.6
13.9
10.9
10.0
9.1
10.0
12.6
10.4
7.4
7.8
.07
.08
.08
.09
.09
.09
.07
.06
.04
.04
= Zz2
SO
9.
11.
10.
11.
12.
10.
12.
16.
12.
9.
10.
8.
8.
7.
7.
8.
10.
11.
10.
.
.
.
.
.
m
4
3
3
0
0
0
3
5
0
0
6
7
6
4
4
9
6
6
8
2
27
29
10
13
17
13
15
09
07
13
Cl
0.3
97.6
0.3
28.8
23.6
30.6
14.5
9.4
1.1
14.4
17.0
16.9
15.2
13.3
12.0
17.8
17.3
18.3
15.7
.02
.05
.02
.05
.02
.05
.06
.06
.06
.05
HC03
3.6
3.8
-
_
-
4.6
-
-
-
-
-
-
-
-
-
-
-
-
.68
.82
.86
.96
.96
.93
.89
.86
.86
.89
mmho / cm
EC1
1.7
8.7
1.9
4.0
4.8
5.0
3.5
3.6
2.5
3.0
2.9
3.1
2.9
2.5
2.3
3.0
3.1
3.6
3.2
-
-
-
-
-
-
-
-
-
^
EC
1.4
8.1
1.3
4.2
4.5
4.5
3.1
2.9
1.9
2.6
2.8
2.8
2.7
2.5
2.3
2.9
2.8
3.0
2.8
-
-
-
-
_
-
-
^
.0137
where m is the molar concentration, z is valance (Griffin, R.A. and J.J.
Jurinak, 1973).
47
-------
Table 13. ELECTRICAL CONDUCTIVITY BY THE HORIZONTAL 4-PROBE MEASURED AT
VERNAL, UTAH ON AUGUST 8-10, 1973.
Depth
cm
0-15
15-30
30-46
46-61
61-76
76-81
91-107
107-122
122-137
137-152
152-168
168-183
Electrical conductivity in mmho/cm
8-8-73 8-9-73
1032 1440 1630 0700 1445 1610 1850
0.36
0.31
0.40
0.43
0.67
0.62
0.62
0.52
0.58
0.68
0.47
0.45
0.54
0.42
0.54
0.60
0.66
0.64
0.60
0.70
0.60
0.55
0.50
0.55
0.54
0.41
0.48
0.62
0.65
0.66
0.54
0.70
0.70
0.50
0.55
0.45
0.43
0.37
0.45
0.65
0.67
0.67
0.33
0.93
0.65
0.40
0.45
0.70
0.86
0.64
0.94
0.74
0.67
0.60
0.80
0.65
0.70
0.50
0.60
0.20
0.85
0.65
0.86
0.68
0.68
0.63
0.67
0.73
0.70
0.55
0.70
0.20
0.80
0.65
0.83
0.65
0.57
0.55
0.80
0.50
0.75
0.50
0.60
0.20
8-10-73
0615 0845 1155
0.
0.
0.
0.
0.
0.
C.
0.
0.
0.
0.
0.
62
59
60
87
85
61
57
52
91
76
40
55
0.64
0.57
0.59
0.90
0.78
0.70
0.62
0.65
0.95
0.60
0.60
0.40
0.72
0.56
0.62
0.84
0.81
0.70
0.70
0.65
0.60
0.60
0.60
0.40
About 10 cm of water, EC = 1.0 mmho/cm, added starting at 1100, 8-8-73
About 10 cm of water, EC = 10.0 mmho/cm, added starting at 1300, 8-9-73
About 10 cm of water, EC = 1.0 mmho/cm, added starting at 1930, 8-9-73
Note that after the first addition of water at 8-8, 1100, the water content
was essentially the same throughout the rest of the experiment.
48
-------
at a very slow rate so that surface water movement on the plot was
minimized. The data are shown in Table 14. The data for the ceramic
cup samplers showed an increase in EC of the extracted soil solution
down to 30 cm after adding the salty water (treatment B). The
replicate samples taken show considerable variability. The solution
is much less salty than would be expected unless something that
effects EC is happening that removes the NaCl from the solution. After
more nonsalty water is added (C) ceramic cup sample measurements
indicate that there is a slight indication of salt moving down. The
1:5 soil samples indicate almost a doubling of EC from A to B and from
C to B. The EC data indicate that most of the added salt had
disappeared after treatment C. The salt could certainly have not been
removed from the profile by treatment C. Thus the data from this soil
show even more strongly than the Vernal trials that something is
occurring to remove most of the NaCl from the soil solution. This
is again an indication of solution, precipitation of exchange occurring.
The four-probe data taken at the same time and shown in Table 15
indicate an increase in EC from A to B only in the top 30 cm. The 10
cm of water should have moved to about 45 cm so these data seem fairly
reasonable. After adding nonsalty water, treatment C, the highest EC
was in the 15 to 30 cm depth as was indicated by the ceramic sampler
data. The data from the four-probe measurements thus agree in general
with the other measured data.
Field Trial 5 - The test made in Logan was to determine if similar
effects of adding salty water would show up on another soil. The 1:5
conductivity (Table 16) data show an increase from treatment A to B
as would be expected in the 30 to 46 cm samples but the increase
should have been much higher if no precipitation of salt occurred.
This increased conductivity should have moved down to the 61 to 76 cm
depth from treatment B to C. There is some indication that this
happened but the increases seem too low. Thus, the data also indicate
the NaCl is somehow being tied up so that it is not contributing to
conductivity.
Laboratory Studies
Laboratory Trial 1 - Results of laboratory studies involving extraction
of soil solution from samples of various water/soil ratios are shown
in Figure 8. The measured data of Figure 8 show the high "buffering"
capacity of the Vernal soil (A) where increasing the water/soil ratio
causes an increase in the relative dissolved salt. These data indicate
that for a soil profile of 200 cm deep, about 400 cm of water would
have to be leached through the profile (assuming a bulk density of
1.2 g/cm3) to remove the soluble salts. If the portion of the curve
up to a water/soil ratio of 0.5 were linear (line B) it would require
200 cm of water to be leached through the soil before the concentra-
tion would change. Under normal irrigation, this may take several
years. 49
-------
Table 14. ELECTRICAL CONDUCTIVITY, EC, FROM CERAMIC SAMPLERS, 1:5
SOIL EXTRACTS AND WATER CONTENT AS A FUNCTION OF TIME AND
DEPTH AT FARMINGTON, UTAH. SEPTEMBER 9-10, 1973.
(mmho/cm)
Treatment
Depth
A 15 cm
A 30 cm
A 46 cm
A 61 cm
A 76 cm
A 91 cm
A 122 cm
B 15 cm
B 30 cm
B 46 cm
B 61 cm
B 76 cm
B 91 cm
B 122 cm
C 15 cm
C 30 cm
C 46 cm
C 61 cm
C 76 cm
C 91 cm
C 122 cm
EC Ceramic
NW NE SE
1.6
1.0
0.7
0.8
0.7
0.6
0.7
1.2
2.5
1.8
1.1
1.0
0.7
0.8
1.1
2.8
1.8
1.0
0.9
0.9
0.9
0.7
1.2
1.0
0.7
0.8
0.7
0.6
1.0
1.0
0.7
0.7
0.8
0.8
0.6
0.9
0.9
0.7
0.8
0.9
0.8
"
0.9
0.9
1.0
1.2
0.8
0.8
-
0.7
0.7
1.0
1.5
1.8
0.8
-
0.9
0.8
1.0
0.8
1.2
0.8
^
Samples EC 1:5
SW Ave Samples
0.8
0.8
-
0.7
0.6
0.7
-
5.0
0.8
0.7
1.5
0.6
0.7
-
0.8
0.8
1.0
1.8
2.8
0.8
~
1.0
1.0
0.9
0.8
0.7
0.7
0.6
2.0
1.3
1.0
.1
1.0
0.8
0.7
0.2
1.3
1.1
1.1
1.4
0.8
0.9
0.08
.08
.10
.07
.06
.08
.05
0.16
.16
.16
.17
.14
.14
.15
.22
.10
.08
.08
.06
.05
.05
Water Content
NW NE SE
.22
.25
.26
.25
.26
.26
.30
.25
.27
.27
.29
.30
.30
.31
.22
.26
.25
.25
.27
.27
.27
.27
.26
.25
.26
.25
.26
.26
.28
.28
.26
.25
.26
.27
.26
.25
.25
.25
.25
.26
.26
.26
.25
.25
.25
.24
.25
.25
-
.27
.26
.24
.25
.25
-
.25
.26
.25
.26
.25
.26
(Vol
SW
.27
.26
.26
.24
.24
.26
-
.26
.28
.26
.25
.25
.27
.29
.26
.26
.25
.26
.25
.26
Fra.)
Ave
0.25
.26
.26
.25
.25
.26
.28
.26
.27
.26
.26
.26
.28
.29
.24
.26
.25
.26
.26
.26
.26
A - After irrigation with about 15 cm of water EC = 0.4 mmho/cm.
B - After irrigation with about 10 cm of water EC = 5.0 mmho/cm.
C - After irrigation with about 10 cm of water EC = 0.4 mmho/cm.
50
-------
Table 15- ELECTRICAL CONDUCTIVITY AS MEASURED BY THE HORIZONTAL 4-
PROBE AT FARMINGTON.
Depth
cm
0-15
15-30
30-46
46-61
61-76
76-91
91-107
107-122
Before
0.14
.29
.21
.25
.22
.15
.10
.14
o
Treatment
A
0.22
.32
.22
.29
.21
.04
.25
.25
B
0.73
.35
.22
.30
.25
.05
.30
.10
C
0.39
.71
.20
.20
.35
.05
.30
.20
Treatments A, B, and C are described in Table 8.
readings made before any irrigation.
Before refers to
Table 16. WATER CONTENT AND VERTICAL 4-PROBE EC AND 1:5 SOIL EXTRACT
FOR LOGAN, JULY 2-3, 1973 TRIAL. EC IN mmho/cm.
Water Content
Volume Fraction
Vertical 4-
Probe
1:5 Soil
Extract
30
46
61
76
91
a -
b -
c -
cm
cm
cm
cm
cm
0.21
.21
.18
.19
.19
Readings
Readings
Readings
0.23
.20
.17
.19
.19
0.
taken after
taken after
taken after
26
22
20
22
22
1.2
1.2
1.3
1.2
1.2
irrigating
irrigating
irrigating
1.4
1.4
1.3
1.1
1.1
with
with
with
1.4
1.4
1.4
1.3
1.2
about
about
about
0.130
.130
.15,0
.141
.161
10 cm of
10 cm of
10 cm of
0.260
.150
.131
.140
.130
water -
water -
water -
0.156
.134
.151
.164
.140
EC=0 . 3
EC=10.0
EC=0 . 3
NaCl was used to increase the EC of treatments b.
51
-------
O
UJ
a
ui
_J
UJ
(T
1.0 1.5
WATER/SOIL RATIO
2.0
2.5
Figure 8. Relatlye dissolved salt for various water-soil ratios
laboratory trial 1.
For comparative purposes, two other extremes are shown in Figure 8,
limited solubility-infinite source OB); and infinite solubility-
limited source (C). Limited solubility-infinite source (B) means
that the source is enough to saturate the soil solution and the total
dissolved salt is directly related to the quantity of the solvent.
Infinite solubility-limited source means that the quantity of extracted
salt is independent of the quantity of the solvent. The measured data
CA) show features similar to both extremes. When the water/soil ratio
is low, the soil appears as an infinite source with limited solubility.
When the water/soil ratio is high the soil approaches a system with a
limited source of infinite solubility. The soil undoubtedly has a
mixture of many salts having different source strengths and
solubilities.
52
-------
Laboratory Trial 2 - Figure 9 summarizes the results of the short
column leaching study. About 16 pore volumes of water were needed to
complete the leaching. Salt balance calculations for this experiment
accounted for all but about 2.5 percent of the total salt, indicating
reasonable accuracy for the experiment. Figure 9 shows the ratio of
C /C as a function of pore volume of effluent. Figure 10 shows EC
(5P) for each segment of the column and effluent EC as functions of
pore volume of effluent. Figure 11 shows a comparison of effluent
EC with EC (4P3) of the bottom segment of the column. The data
indicate a good linear relation between the two methods of estimating
EC. Thus it appears that the EC (4P) may be capable of estimating EC
of the soil solution in small saturated columns once a good calibration
for the soil and geometrical configuration of the 4 electrodes is
attained.
It is apparent from the results of the short column leaching study that
a large quantity of water is required to completely leach the soil.
Thus there must be large quantities of relatively low solubility salts
existing in this particular soil.
Model Predictions
The procedure followed in using the model was to compute the conse-
quences of various given irrigation management sequences for a typical
season as a function of soil and crop conditions for that season. The
following inputs were varied and the outputs as a result of the
variation were predicted.
Input Data - Irrigation was applied according to the irrigation
frequency actually used in 1971 which was described in detail in King
and Hanks (1973). The ET relations were also the same as given
earlier for 1971. The amount of irrigation applied each time was
varied from zero to sufficient to cause considerable damage. Thus
the irrigation frequency was the same for all treatments but the
irrigation amounts were different.
The initial salt concentration of the profile was assumed to be
uniform at the beginning of the season at 20, 50, or 200 meq/1. The
20 meq/1 concentration was about the same as conditions existing on
the Hullinger farm. The 50 and 200 meq/1 were used to simulate salt
buildup that would occur over several years time if proper irrigation
and drainage were not practiced.
Three root depths were simulatedshallow, medium, and deep. Since
calculations estimated pnly dry matter these results apply for forage
and could be less accurate if grain yield predictions are made CHanks,
1974).
The shallow rooted crop was assumed to be an annual crop, like oats,
which, developed full coyer fairly quickly. The medium rooted crop
53
-------
6 8 1C
PORE VOLUME
12
14
16
Figure 9. Ratio of EC of irrigation water to EC of effluent as a
function of pore volume of the effluent - laboratory
trial 1,
-------
E
u
E
E
Q»
«£
H-
Q>
*-
o
o
Hi
EC of Effluent
YB,
YPI
YFj Ist RING
YP2 2ndRING
YP, 3rdRIN6
o
I
I
1
40
30
20
10
5 6789 10
PORE VOLUMES
II
12 13 14 15
o
x:
E
I
o
UJ
UJ
m
o
Figure 10. Comparison of curves for effluent EC and 4-probe EC as related to pore volume - laboratory
trial 2.
-------
EC« -0.49+ 0.0653 P4
14 18 22
4- Probe EC In mmhos
Figure 11. Comparison of effluent EC with 4-probe EC of bottom column section - laboratory trial 2,
-------
was assumed to be a perennial crop, like alfalfa, which had full cover
all year- The deep rooted crop was assumed to be an annual row crop,
like corn, which, started out with bare soil and took about 60 days to
develop full coyer. Computations made show that the year end results
are only slightly influenced by these root depth and cover development
assumptions.
Table 17 shows the root distribution function used. The initial water
content profile and soil water properties were assumed to be the same
as those of 1971. These data are given in King and Hanks (1973). The
salt concentration of the irrigation water was originally used as a
variable. However, after some preliminary computation with rather
drastic changes in concentration, it was apparent that this input has
little influence on the results and would have an effect only after
several years. Thus the irrigation water was assumed to have a
concentration of 6.35 meq/1 throughout. Thus yearly buildup was
simulated as different initial salt concentrations. There was an
assumed water table at 235 cm which had a constant concentration equal
to the initial concentration of soil solution throughout the season.
Predicted Results - Table 18 shows the effect on various soil and
water properties of varying the water added and initial salt concen-
tration for the deep rooted crop. The data on T/T is of primary
interest because it is assumed to be directly related to relative
yield. The data in Table 18 show, as would be expected, that T/T
increases as the irrigation applied increased up to about 46 cm after
which the ratio was essentially 1.0 for all initial salt concentrations.
However, T/T was less than 0.9 where irrigation was less than 6, 9,
and 26 cm for" an initial salt concentration of 20, 50, and 200 meq/1
respectively. There was relatively little difference on T/T due to
an initial salt concentration of 20 or 50 meq/1 but there wa6 a marked
influence when the initial salt concentration was 200 meq/1. Thus
the irrigation management used with the 20 meq/1 initial profile salt
concentration can be considered to be nearly salt free and the results
are due to water influences only. Note that where the irrigation and
rain was less than about 20 cm there was nearly an equal amount of
upward water flow from the water table showing that the amount of
flow was limited by soil water transmission and plant root extraction.
Where the initial salt concentration was 200 meq/1, upward flow was
about 2.5 cm less than for the higher initial salt concentrations.
However, drainage (downward flow) was influenced very little by initial
salt concentration.
A unique feature of the data shown in Table 18 is the large influence
of wa,ter povement up from the water table Cat 235 cm). The soil
properties at the Hullinger Farm seem to be especially cpnducive to
high, water flow in both directions. Other situations with, other soils
would probably not result in as muck upward flow as shown in Table 18.
57
-------
Table 17. RELATIVE PROPORTION OF ROOTS AT DIFFERENT DEPTH
INCREMENTS AT MATURATION ASSUMED.
Depth
(cm)
2.5 to 10.5
10.5 to 25.5
25.5 to 52.5
52.5 to 91.5
91.5 to 140.0
140.0 to 235.0
Deep
.09
.20
.34
.25
.12
0
Medium
.14
.30
.33
.23
0
0
Shallow
.18
.40
.42
0
0
0
The data shown in Table 18 are only a small part of the data generated
by the model to attain these summary values. Each line represents one
complete season where data has been computed at several depth increments
and at no greater than 2 to 3 hour time increments. Thus data within
the season are also available. Figure 12 shows a comparison of
cumulative evapotranspiration as influenced by initial salt concentra-
tion for two different irrigation levels.
Table 19 shows the computation made for a medium rooted crop. The data
show greater decreases in T/T for low irrigation rates than were shown
for a deep rooted crop. Upward water flow was less for the medium
than for the deep rooted crop. The data show little difference between
the 20 and 50 meq/1 initial salt concentrations but fairly large
differences with 200 meq/1 initial salt concentrations. Thus the T/T
depression at 20 meq/1 initial salt concentration is due to inadequate
irrigation. The differences in T/T at any one irrigation level,
between 20 and 200 meq/1, were due Ilightly to a salt effect. Where
15 cm pf irrigation and rain was applied T/T was Q.68 because water
was insufficient to uwintain transpiration. ^A further reduction of
T/T from 0.68 to 0.49 resulted from the high, initial salt concentration.
Table 20 shows the computed data for the shallow rooted crop. The
Values of T/T were smaller for the shallow^rooted crop, for a given
irrigation refijue, than for either of the deep rooted crops. WitH
the shallow; root zone, upward flow was less than. 4 cm. This caused the
ratio, T/T , to be less than 0.9 Cfor 20 meq/1 initial salt concentra-
tion) wherl irrigation and rain was less than about 52 cm. The T/T
58
-------
Table 18. COMPARISON OF IRRIGATION WATER APPLIED AND INITIAL SALT CON-
CENTRATION ON RELATIVE TRANSPIRATION, T/Tp, TOTAL WATER USED,
DRAINAGE, SALT FLOW TO THE GROUNDWATER AND AVERAGE FINAL SALT
CONCENTRATION FOR THE DEEP-ROOTED CROP.
Irriga-
tion and
Rain
(cm)
5.6b
5.6
5.6
10.3
10.3
10.3
15.0
15.0
15.0
22.0
22.0
22.0
40.8
40.8
40.8
56.4
56.4
56.4
66.7
66.7
66.7
-
ET
(cm)
40.3
38.6
6.2
3.9
2.1
30.1
47.7
46.3
34.6
9.0
9.2
1.2
50.4
48.3
48.1
51.9
52.2
56.7
51.7
51.6
51.6
T
35.3
33.5
20.6
36.6
35.1
22.3
38.6
37.2
25.1
38.5
38.7
30.9
37.6
35.9
35.8
37.3
37.3
37.3
37.3
37.3
37.3
T/Tp
.81
.77
.48
.89
.86
.55
.97
.93
.64
.98
.98
.78
.99
.98
.97
1.00
1.00
1.00
1.00
1.00
1.00
Drainage
(cm)
-14. 2a
-14.2
-11.6
-14.1
-14.0
-11.4
-14.0
-13.9
-11.4
-13.6
-13.5
-11.9
- 8.7
- 7.1
- 6.2
+ 0.91
+ 1.0
+ 1.1
+10.5
+10.6
+10.8
Salt Flow
to
Ground-
water
(meq)
- 284
- 710
-2320
- 282
- 700
-2280
- 280
- 695
-2280
- 272
- 675
-2260
- 174
- 355
-1240
19
49
214
210
532
2160
Initial
Salt
Concen-
tration
(meq/1)
20
50
200
20
50
200
20
50
200
20
50
200
20
50
200
20
50
200
20
50
200
Final
Salt
Concen-
tration
Average
(meq/1)
62
127
305
60
120
296
56
116
296
40
95
291
27
604
227
23
50
189
20
42
153
A negative sign indicates upward flow.
Rain was 5.6 cm. Each line represents a computation for the same
irrigation efficiency but different amounts of water applied, for the
1971 climatic conditions at Vernal, Utah.
59
-------
5O r-
E
o
iLl
LJ
i
4O
3O
20
5
D
O
IO
I +R = 56.4cm (2O MEQ/LV
R =IO.3cm
(2O MEQ/L)
= IO.3cm
(2O MEQ/L)
2O
4O 6O 8O
TIME, days
IOO
120
Figure 12,
Comparison of cumulative evapotranspiration vs. time for two water appli-
cation amounts and two initial soil solution concentrations.
-------
Table 19. COMPARISON OF IRRIGATION WATER APPLIED AND INITIAL SALT CON-
CENTRATION ON RELATIVE TRANSPIRATION, T/Tp, EVAPOTRANSPIRA-
TION, ET, DRAINAGE, SALT FLOW TO THE GROUNDWATER AND AVERAGE
FINAL SALT CONCENTRATION FOR THE MEDIUM-ROOTED CROP.
Irriga-
tion and
Rain
(cm)
5.6b
5.6
5.6
10.3
10.3
10.3
15.0
15.0
15.0
22.0
22.0
22.0
40.8
40.8
40.8
56.4
56.4
56.4
66.7
66.7
66.7
ET
(cm)
29.5
28.2
19.8
33.2
32.1
24.2
37.6
36.5
28.8
43.9
42.9
35.3
51.7
51.3
48.1
53.4
53.9
53.9
53.5
53.1
53.2
T
25.8
24.6
16.0
29.2
28.1
20.0
32.8
31.8
23.7
38.6
37.6
30.1
46.7
46.3
43.2
48.2
47.9
47.9
48.3
48.3
48.3
T/Tp
.52
.50
.33
.61
.58
.42
.68
.66
.49
.80
.78
.63
1.00
1.00
.93
1.00
1.00
1.00
1.00
1.00
1.00
Drainage
(cm)
-9.7a
-9.4
-7.8
-9.5
-9.3
-7.7
-9.3
-9.2
-7.6
-9.4
-9.2
-7.5
-7,4
-6.7
-5.6
0.0
+0.4
+0.3
+8.8
+9.3
+9.4
Salt Flow
to
Ground-
water
(jneq )
- 195
- 472
-1561
- 189
- 466
-1860
- 154
- 458
-1840
- 148
- 461
-1840
- 148
- 370
-1340
0
22
61
178
467
1882
Initial
Salt
Concen-
tration
(meq/1)
20
50
200
20
50
200
20
50
200
20
50
200
20
50
200
20
50
200
20
50
200
Final
Salt
Concen-
tration
Average
(meq/1 )
43
97
277
42
94
269
43
94
268
41
92
263
30
64
228
24
52
195
22
44
158
A negative sign indicates upward flow.
Rain was 5.6 cm. Each line represents a computation for the same
irrigation efficiency but different amounts of water applied, for the
1971 climatic conditions at Vernal, Utah.
61
-------
Table 20. COMPARISON OF IRRIGATION WATER APPLIED AND INITIAL SALT CON-
CENTRATION ON RELATIVE TRANSPIRATION, T/Tp, EVAPOTRANSP1RA-
TION, ET, DRAINAGE, SALT FLOW TO THE GROUNDWATER AND AVERAGE
FINAL SALT CONCENTRATION FOR THE SHALLOW-ROOTED CROP.
Irriga-
tion and
Rain
(cm)
5.6b
5.6
5.6
10.3
10.3
10.3
15.0
15.0
15.0
22.0
22.0
22.0
40.8
40.8
40.8
56.4
56.4
56.4
66.7
66.7
66.7
ET
(cm)
18.3
18.0
14.3
22.7
22.2
18.4
27.1
26.7
22.9
33.8
33.4
29.5
46.0
45.7
42.3
53.6
53.4
51.4
52.5
52.5
52.5
T
13.3
12.9
8.2
16.4
16.1
10.2
20.2
19.4
13.3
25.6
25.3
19.3
35.2
35.1
31.5
38.5
38.8
37.0
38.6
38.6
38.6
T/Tp
.29
.28
.18
.37
.36
.24
.46
.44
.32
.59
.58
.46
.89
.88
.80
.97
.98
.93
.99
.99
.99
Drainage
(cm)
- 3.8a
- 3.8
- 3.6
- 3.8
- 3.8
- 3.5
- 3.8
- 3.8
- 3.5
- 3.8
- 3.8
- 3.3
- 2.5
- 2.4
- 1.2
+ 1.3
+ 1.3
+ 2.5
+10.0
+10.0
+ 9.9
Salt Flow
to
Ground-
water
(meq)
- 74
-191
-718
- 76
-190
-700
- 76
-189
-700
- 76
-190
-660
- 50
-120
-240
26
66
490
198
495
1975
Initial
Salt
Concen-
tration
(meq/1)
20
50
200
20
50
200
20
50
200
20
50
200
20
50
200
20
50
200
20
50
200
Final
Salt
Concen-
tration
Average
(meq/1)
33
78
248
33
76
242
33
76
242
33
76
40
26
58
208
24
52
185
20
43
157
aA negative sign indicates upward flow.
Rain was 5.6 cm. Each line represents a computation for the same
irrigation efficiency but different amounts of water applied, for the
1971 climatic conditions at Vernal, Utah.
62
-------
results with 50 meq/1 initial salt concentration were only slightly
different than for 20 meq/1 whereas, the T/T results for 50 meq/1
were considerably larger where the initial sSlt concentration was
200 meq/1.
A feature of the model computation is especially noticeable in Table 18
for the deep rooted crop. The computer program allows for the
possibility that if evaporation is less than potential evaporation,
the difference, E - E, can then be used in transpiration. Thus
potential transpiration is not a constant in Table 18 but increases
as applied irrigation and rain decreases. Thus for a rain of 5.6 cm,
T was 40.3 and for irrigation and rain of 56.4 cm, T was 37.3 cm.
Hanks et al (1971) demonstrated that this energy "trading" occurs,
but it may be that the model computation over corrects for it.
Figure 13 shows the salt concentration profile at the end of the
season compared to the initial salt concentration for three different
levels of water addition for the deep rooted crops. Where irrigation
was insufficient to cause drainage, there was a higher concentration
of salt throughout the profile at the end of the season than at the
beginning. There was a very pronounced peak in salt concentration
just below the root zone particularly for small water applications.
Figure 13 also shows the salt concentration profiles at the end of the
year for the shallow rooted crops. The salt concentrations are higher
in the profiles than for the deep roots because of the more shallow
root distribution. With rain only there was relatively little water
available for transpiration so the salt peak was lower than where 22
cm of irrigation and rain provided sufficient water for more
transpiration and thus more concentration of salt. Where sufficient
water for some leaching was available the salt concentration was
essentially constant throughout the profile.
Figure 14 shows a simulation over several years where irrigation and
rain were about one-half ET. The data indicate no decrease ^Ln the
T/T ratio until the seventh year, after which the ratio fell rapidly
until the 10th year when it appeared to be leveling off. Figure 14
also shows the average salt concentration buildup which by the
10th year had almost leveled off at about 260 meq/1. Where T/T
decreases, the transpiration decreased until the IQth year ET hid
decreased by 15 cm and was only 9 cm greater than the water added.
The difference between the water added and ET came from soil water
storage and water flow up from the water table. Note that the
particular results computed for a simulated run pf 10 years, is highly
dependent on the particular situation. If a crop with shallower roots
had been used, an entirely different result would have been obtained.
One of the purposes of the computation over several years time was to
see how these results compared with the data of Table 18 where differ-
ent initial salt concentrations were used to simulate salt build up.
For the same irrigation schedule, the data of Table 18 indicate a T/T
63
-------
SALT CONCENTRATION, meq/liter
O 5O IOO ISO 2OO
INITIAL
5.6cm RAIN
22.Ocm RAIN + IRRIGATION
66.7 cm RAIN + IRRIGATION
0- 200
5.6cm RAIN
2OO
I5O1-
Figure 13.
22.Ocm RAIN + IRRIGATION
'66.7 cm RAIN + IRRIGATION
INITIAL, 2O MEQ/LITER
OATS
Salt concentration profiles at the end of the season for
three water application amounts for a deep rooted crop and
a shallow rooted crop.
64
-------
CORN IRRIGATION = 24.4 cm
OS
Ul
ET, cm
48 48 48 48 48 48 44 38 34 33
SALT
CONCENTRATION
4567
TIME, years
8
10
Figure 14. Computations made of relative transpiration, T/Tp, and average salt
concentration as influenced by time where the water application
amount was about 22 cm deep for the deep rooted crop.
-------
ratio of 0.90 for an initial salt concentration of 200 meq/1 that
ended one season with an average profile salt concentration of 296
meq/1. The data of Figure 14 indicate essentially the same ratio of
T/T although the salt concentration at the end of that particular
year is not as high as that of Table 18. Thus it is concluded that
assuming an initial uniform salt concentration throughout the profile
at the beginning of the year gives essentially the same results as
taking the developed concentration profile from the previous year.
Using the concentration profile at the end of the crop season for the
input data for the next spring may be somewhat erroneous because the
profile would tend to equalize somewhat over the winter by diffusion
and mass flow up and down due to rainfall, evaporation, and drainage.
Validity of Model Predictions - In view of the apparent high
"buffering" capacity of the different soils on which field and
laboratory tests were made, the question ariseshow valid are the
model calculations? If the field measurements are taken as being
representative of what happens during normal management manipulations,
a model could be devised which would account for water flow and the
assumption made that salt concentrations would not change appreciably
with time. Thus to compute salt flow it would only be necessary to
multiply the water flow by the salt concentration at the bottom of
the profile. This approach would probably be valid for many years
where leaching is moderate (about 10 percent of the irrigation). Thus
little influence of salinity management on crop yield would result.
Estimates made by the simple salt flow model, as done herein, would
yield results that tend to overestimate the effects of salinity on
crop yield if some salt storage (by precipitation, solution exchange,
etc.) takes place. Thus the true picture is probably somewhere in
between. There is a certain danger in the conclusion that salt buildup
will not be harmful, because this can be true only for a limited number
of years. It would seem more useful to use the more conservative
estimate.
Another factor that would tend to favor use of the conservative approach
for management prediction would involve the assumption that the osmotic
component is the only detrimental effect of salinity. This assumption
would tend to counterbalance the neglect of salt oeing taken out of the
soil solution.
Regardless of which of the two extremes is used to develop a model, it
is apparent that salinity effects do not occur ifi a short time but
rather develop over many years and are thus capable of being influenced
by many factors. This long term effect wakes conclusions based on a
few years of field research, very risky indeed.
66
-------
NITROGEN MOVEMENT
Commercial Fertilizer Plots
Plots (30.5 m x 54.9 m) treated with Ca(N03l2 in 1972 were planted part
to corn and part to alfalfa Csee Figure 1). Figure 15, shows
nitrate nitrogen data taken shortly after Ca(N03)2. additions and
illustrates that the N03-N was in the surface 30 cm and in about the
correct proportions for the 110 kg/ha and 440 kg/ha rates in the corn
plots. See Appendix B, Table B-14 for detailed data. However, to have
all of the added N03-N evenly distributed in the 0-30 cm depth would
produce a leaching of about 90 ppm for the 440 kg/ha rate. The N03-N
added to alfalfa was irrigated into the soil. Obviously some of the
N03-N was leached below 30 cm.
After the growing season, soil samples showed a higher N03-N content
in the corn plots treated with 110 kg/ha than 440 kg/ha of N03-N
(Figure 16). This result must be due to an error in sampling because
a total of only about 25 ppm would be expected if all of the fertilizer
was contained in the profile. The September sample of the 0-30 m
depth also is low which would cause the October data to be questioned.
The values in the 440 kg/ha treatment seemed more realistic, assuming
there was little leaching or gaseous losses. About 90 to 100 ppm
total would account for all added N03-N at the 440 kg/ha rate. Figure
15 illustrates that alfalfa plots had less extractable N03-N than the
corresponding corn plots. Additional soil samples of the top 30 cm
of soil taken in September 1972 showed less than 4 ppm N03-N extracted
for all samples (Figure 16). This would have been near maturing time
for the corn and may have had lower N03-N levels than would exist in
October.
The 1973 soil samples indicated similar N03-N contents for many of the
treatments (Figure 17). The figure shows alfalfa and corn plots
grouped together. The separated average values are shown in Table 21
Csee Table B-15, Appendix B for detailed data). Generally, alfalfa
plots with the same added fertilizer were lower in N03-N than were
com plots. However, the difference is not as marked as is indicated
by the 1972 data (Figure 16). Assuming that some N03-N might be
residual from the previous year, a summation of about 150 ppm N03-N
in the four 30-cm increments might be expected for the 440 kg/ha
rate. About 40 to 50 ppm might be expected in the 110 kg/ha rate. The
values for corn plots do not exceed these estimates in the June 20
sampling if the values for the control plots are subtracted to approxi-
mate only added N03-N. By September 19 the total N03-N had decreased
in all treatments. Some loss estimates of N03-N based on general
conversion values are given in Table 22. These losses may be
conversions to organic forms or actual losses.
67
-------
ALFALFA PLOTS
CORN PLOTS
00
N WATERED
INTO PLOT
**
N PLOWED
INTO PLOT
Figure 15. Nitrate-N in the soil samples from plots with varying amounts of Ca(1*103)2 fertilizer spread
on the soil surface. Sampled June 28, 1972 shortly after the fertilizer was added.
-------
OCTOBER 7,1972
-------
119.2
N03-N (N SOIL SAMPLES
HULLINGER FARM
LARGE PLOTS, CORN AND ALFALFA
Co (N03)2 FERTILIZER
crr.«v
JUNE 20, 1973
SEPTEMBER 19, 1973
Figure 17. Nitrate-N (ppm) in soil profiles as a result of different applications of
in 1973.
fertilizer
-------
Table 21. SOIL N03-N CONTENTS IN SOIL SAMPLES TREATED WITH VARIOUS
RATES OF NH4N03 AND PLANTED TO CORN OR ALFALFA. HULLINGER
FARM, VERNAL, UTAH, 1973.
NH4N03
added
Control
110 kg /ha
220 kg/ha
440 kg/ha
Table 22. NO
NH.NO. Added
4 3
(kg/ha) a
Control (0)
110
220
440
Soil
Depth
0-30
30-61
61-91
91-122
0-30
30-61
61-91
91-122
0-30
30-61
61-91
91-122
0-30
30-61
61-91
91-122
-N LOSS FROM
N03-N
in
June 20 Sampling
Alfalfa
cm
6
5
2
0.4
14
15
1
0.5
32
20
4
2
56
25
5
4
JUNE 20 TO
Alfalfa
Corn
ppm
25
9
5
6
51
20
5
4
140
25
20
20
SEPTEMBER 19,
Plots
N03-N in
Sept. 19
Alfalfa
cm
5
1
1
0.5
3
0.6
1
0.2
2
1
10
0.3
5
42
11
5
1973.
(kg/ha) a
25
100
150
100
Sampling
Corn
ppm
5
1
1
1
12
7
5
2
22
67
24
13
Corn Plots
(kg/ha)a
120
200
320
Deduction of ppm times 4 approximates kg/ha.
71
-------
Ceramic cup solution analyses for 1973 verify the 1972 soil data that
NOa~N contents in alfalfa plots were lower than in corn plots (Figure
18 and Table B-16). When Campled periodically at 76 cm and 106 cm
depths, almost no NOa~N was obtained in the alfalfa plot soil extracts
except from the 106 cm depth on plots having 440 kg/ha added. The
values were between 36 and 59 ppm NOa~N. In contrast, the corn plots
had values between 37 and 124 ppm NOa~N in extracts from the 440 kg/ha
treatment at both the 76 and 106 cm depths. The 110 kg/ha rate plots
and even the unfertilized control plots contained up to 21 ppm NOa~N.
The drainage water NOa-N content tends to verify soil analyses and
soil extract contents of NOa-N. Heavily fertilized corn plots (440
kg/ha) lost N03-N approaching 20 ppm during the first two months (June
and July) but the loss dropped to less than 10 ppm in fall (Figure
19). The alfalfa plots lost less N03-N with drainage water values,
commonly less than 5 ppm. The relatively high value of about 8 ppm
as a mean value for NOa~N in drainage water from the control plot is
probably due to mixing of drainage water and lateral flow from outside
the plots. One of the two control plots is within 50 m of a private
home septic tank and drain field. NOa-N values from the control plot
furthest away from the home did not exceed 7 ppm and most were 3 to
5 ppm. Thus the only treatment that definitely caused increased NOa~N
in the drainage water was the 440 kg/ha level in corn.
Attempts to use NOa~N measurements of drain effluent from the
commercial fertilizer plots as a measure of NOa~N movement through the
root zone were not successful. Tables B-18 and B-19 of Appendix B
give detailed results of the effluent concentration of NOa-N. Note
that one of the control drains (6N) had N03-N concentrations for 1973
which were nearly as great as for 5M and significantly greater than
4M, both of the latter receiving applications of fertilizer at the
rate of 440 kg/ha. Nitrogen balances including the drain effluent
were not attempted because of the above observation and the encroach-
ment of groundwater from outside the farm boundaries. The plots were
designed to include a dilution factor. The treatment area was about
30 m by 55 m (1650 m2) while the surface area of water application was
about 61 m by 70 m (4270 m2). Thus the water percolating below the
treated area to the water table should have been diluted by a factor
of about 0.4 by the irrigation water percolating from untreated areas.
The above procedure assumes no mixing with other groundwater and that
all water flow in the drain originated from application of water to
the surface 61 m by 70 m area. This discussion will not be pursued.
A very minor study of the effect of drain submergence on NOa~N
discharge was attempted. Drains 5N and 5M were submerged to a depth-
saturating the gravel envelope surrounding the drain pipe. The degree
of the submergence obtained is indicated by water table depths of
Table 7, Note that the average water table depth measured for plot
5N was less than any other north plot for both- years of study, while
plot 5M had an average water table deptK essentially the same as other
middle plots. This indicates that the natural drainage conditions
72
-------
ALFALFA PLOTS
CORN PLOTS
10
Figure 18. Nitrate-N (ppm) in ceramic sample extracts at 76 cm and 106 cm depths.
fertilizer was added in 1972 and NH4N03 fertilizer added in 1973.
-------
I I I I I I I I I i I I I I I I I I I I
440 kg N, CORN
15
6-30 7-15 7-30 8-14 8-29
DATE OF SAMPLING (MONTH-DAY, 1973)
9-13
CONTROL, CORN
ALFALFA + 110 kg N
CORN + 110 kg N
ALFALFA + 440 kg N
CORN + 440 kg N
Co (N03)2
Figure 19. Nltrate-N content in drainage waters collected in 1973.
-------
were such to not allow the water table under plot 5M to rise sufficient
to effectively submerge the drain. The maximum submergence of the
drains relative to a free flowing drain was 25 cm as indicated in
Section IV, Methods.
Since drain 5N was the only drain which appeared to be submerged (i.e.,
water in the drain not in direct contact with outside air), for 1972
we could compare N03-N discharges of drains 5N and SAN which had the
same water and fertilizer application to overlying plots. Table B-18
shows significantly less concentration of N03-N in the effluent of
drain 5N than drain SAN. Table 4 shows that in 1972 plots 5A and SAN
received the same amount of irrigation water within 5%. Table B-19
also shows lower concentrations in the drain effluent of 5N compared
to SAN.
The tendency would be to conclude that submergence of the drain in the
field would lower the discharge of N03-N. Again the encroachment of
groundwater from outside the farm boundaries complicates the picture.
For example, Table 5 shows that discharge of water from drain 5N was
nearly 6 times that from SAN for the 1972 season and more than 7 times
that for drain SAN for 1973.
Manure Plots
When high rates of manure are added to soils, the possibility exists
of producing nitrates that leach into groundwaters. Whether or not
nitrates move downward in the soil profile depends on the rate and
amount of nitrates produced, the amount of water moving through the
soil and the rate of denitrification. The rate of nitrate production
should increase with heavier rates of manure or fertilizer application.
The sandy clay loam-sandy loam textures of the farm soil are permeable
and permit easy movement of water. The presence of a water table
between 120 and 180 cm could allow for high water contents of the
deeper subsoil which will favor denitrification. The denitrification
process requires three major factors: (1) A source of nitrate to be
reduced to N2 and oxides of nitrogen, (2) oxidizable carbon as energy
sources for the denitrifying bacteria, and (3) a lack of gaseous 02.
Manure added to the soil and a water table in the lower subsoil
furnish these conditions. However, within the 122 cm depth studied,
a condition of poor aeration was obvious in only a limited few layers
of some, profiles. This would suggest that nitrates may move readily
within the profile to the depth of sampling.
The irrigation water applied to the manure plots can be obtained from
Table 4. For 1972, block 9 shows irrigation of manure plots and some
surrounding area. For 1973, the west part of block 9 shows the
irrigation for the manure plots.
Nitrate is mobile in the soil used but isr in low amounts except when
added (Figure 20). Soil samples taken June 28, 1972, after the first
manure was incorporated had almost no N03-N concentrations except in
the 0 to 30 cm depth. See Table B-2Q, Appendix B for detailed data.
75
-------
CORN PLOTS
SUDAN GRASS PLOTS
Figure 20. Nitrate-N (ppm) in soil profiles as influenced by manure rate applied. Sampled June 28,
1972. Manure applied May 1972.
-------
The relatively high value of 25 ppm N03-N in the control plot planted
to corn seems a little high. The average value is 10 to 12 ppm higher
than four of the five replications because of a single high value of
72 in one plot. The general residual nitrate level before treatments
is very low. Profile soil samples taken October 7, 1972, had N03-N
dispersed throughout the 122 cm depth (See Figure 21). The N03-N
values are still low; lower in the corn plots than in the sudan grass
plots. Appreciable N03-N existed even to the 91-122 cm depth (34 ppm)
on the heavy manure treatment. The N03-1T in the control plots under
both crops was low with a high value of 7 ppm. The moisture content
of the soils was about 0.20 by volume fraction. Thus the N03-N in soil
solution might be expected to be about 5 to 6 times greater than in a
sample of the wetted soil, provided all N03 is in the water. Figure
22 shows N03 N contents of water samples taken by porous, ceramic cups
(106 cm deep) to be about 4 to 10 times higher than soil sample values
(See also Table B-21, Appendix B). In the unmanured plots (control)
the N03-N increased to a maximum during the growing season and dropped
off in the fall. At higher manure loading rates the N03-N maximums
reached were higher, and did not show any consistent tapering-off in
the fall.
The apparent inconsistency of high fall N03-N levels in corn in the soil
solution but low values in the soil samples (Figures 21 and 22) when
compared to the sudan grass data is not readily explained. The soil
samples were taken three weeks after the last soil solution sample.
Drainage losses or other modifications could have occurred.
The high of 76 ppm N03-N in the control plot under corn (Figure 22) may
be partly a result of lateral water flow. Other evidences in the
study indicate that some lateral flow does affect samples near the
water table which may fluctuate at near the 106 cm depth of the sampler.
Nitrate concentrations in the soil profile remained high in the second
year (1973) with generally the highest values in the surface 30 cm of
soil of plots receiving the most manure (Figures 23 and 24 and Table
B-22). In the June 20 sampling, the application of manure for the
second consecutive year to one block of plots resulted in relatively
little changes in N03-N contents in the soil except at the lowest rate
(54 mt/ha). The 108 and 216 mt/ha rates for both blocks varied roughly
from 20 to 100 ppm N03-N. This high. N03-N in plots having manure added
the previous year was not expected. The September 19, 1973 samples
were a similar pattern, but did tend to have more N03-N in the soil
when lower manure rates were applied two consecutive years than when
only the 1972 application was made. It is interesting that the fall
Soil samples from planted control plots all had less than 10 ppm NO3-N
whereas those samples from plots with, added manure still had NQ3*-N
leyels mostly from 30 to 70 ppm.
The data of suction cup extracts agree with the N03-N distribution
pattern found in 1973 (Figure 25 and Table B-23). Control plots had
77
-------
CORN PLOTS
OO
OCTOBER 7, 1972
SUDAN GRASS PLOTS
*x x
Figure 21. Nitrate-N (ppm) in soil profiles as influenced by manure rate applied. Sampled October 7,
1972.
-------
CORN PLOTS
vj
VO
NO^-N FROM SUCTION CUPS AT
106 cm, IN ppm
1972
SUDAN GRASS PLOTS
»
Figure 22. Nitrate-N (ppm) In soil extracts from ceramic samples at 106 cm depth in 1972 as influenced
by manure treatment.
-------
00
o
N03-N IN SOILS
JUNE 20, 1973
MANURE IN 1972 ONLY
MANURE IN 1972 AND 1973
Figure 23. Nitrate-N (ppm) in soil profiles as influenced .by manure treatment, sampled on June 20, 1973.
-------
N03 -N IN SOIL S
SEPT. 19, 1973
GO
&
<%
MANURE IN 1972 ONLY
MANURE IN 1972 AND 1973
Figure 24. Nitrate-N (ppm) in soil profiles as influenced by manure treatment sampled on September 19,
1973.
-------
00
N)
N03~N FROM SUCTION CUPS AT 106 cm,
IN pp m
*0 **
&
MANURE APPLIED IN 1972 ONLY
MANURE APPLIED IN 1972 AND 1973
Figure 25. Nitrate-N (ppm) in soil extracts from ceramic samples at 106 cm depth in 1973 as
influenced by manure treatment.
-------
-N concentrations in the solution of 13 to 54 ppm whereas the
plots with higher manure rates had solutions with many values over
150 ppm.
The plots with two consecutive years of manure applications had almost
identical NOs-N concentrations and concentration patterns as the plots
in the second year which had only a single application of manure a
year earlier. This is surprising. Researchers generally have predicted
about 50 to 60 percent release of manure-N the first year and less
than another 25 percent of the initial total N added in manure will
be released during the second year. In this study so far, NOj-N
concentrations in soil samples or in extracts collected through
installed suction cups has not appreciably lowered during the second
year after manure application in spite of appreciable crop removal of
N the first year. Even a second year's application of manure did not
seem to build up the N03-N concentration levels noticeably (Figure 23).
Salt Contents - Salt concentrations in the soil solution indicate that
salt could become a problem if leaching was not done periodically when
large quantities of manure are added to the soil. Figures 26 and 27
illustrate the extreme conductivities measured. The suction cup soil-
water extracts collected in 1973 had over half the individual samples
having EC values over 4 mmho/cm. Eight samples had values exceeding
8 mmho/cm. This is not surprising, since manure is known to contain
appreciable quantities of soluble salts. It is obvious from the
spread of points in Figure 26 and 27 that there is no close relation-
ship between N03-N content and salinity. Obviously, heavy manure
additions should increase both salt and N03-N contents, so a noticeable
correlation is apparent and real, but not adequate for predictive
purposes. See Table B-24 and B-25 in Appendix B for details of EC
measurements on water samples extracted from soils of the manure plots.
This increase in salt is more obvious by referring to values in Table
23 for the samples collected in the 1972 summer and to Figures 26 and
27 for 1973 samples. In 1972, conductivities mostly ranged between
3 and 4 mmho/cm except a few values near 5 mmho/cm where larger manure
applications were made. In 1973 samples increased in conductivity
almost 1 mmho/cm over 1972 values for plots receiving the larger
amounts of manure. The 1973 plots with 216 mt/ha of manure had an
average conductivity of 6.0 mmho/cm compared to 4.5 mmho/cm for those
plots in 1972. This value of 6.0 mmho/cm was the same for both blocks
of manure plots., one with only 1972 manure application and the other
with applications in both 1972 and 1973. This is surprising since
sprinkler irrigation was intended to be heavy enough to remove water
and thus soluble ions downward in the profile. Since these
conductivity values are for solutions obtained at 106 cm deep,
perhaps sufficient salt was leached to this depth in 1972 even though
it was also present in the soil profile at shallower depths.
83
-------
t.
It
3550
Oij297
429
9.6
00
E
a
a
I
lio
O
250
200
50
100
50
i i r
MANURE APPLIED IN
1972 AND 1973
0 S2I6 mt/ha
x Sl08mt/ha
« 54mt/ha
O s 0 MANURE
ADDED
8
!
XX
OB
x o
0 x
o
O q<
n
fi
x
X
1
1.00 2.00 3.00 4.00 5.00 6.00 7.00
ELECTRICAL CONDUCTIVITY,mmhos/cm
8.00
9.00
Figure 26. Comparison of electrical conductivity versus NO -N collected from ceramic samplers
from manure plots in both 1972 and 1973.
-------
250
200
00
Ui
Q.
O.
z
150
100-
50
MANURE APPL
__ IN JUNE
" a
IED ONLY ° a
1972 a x _
0 =216 mt/ha x ti
* s |08 mt/ha x x Q»
_ = 54 mt/ha . * n ° ~
x x u ^*
0 » 0 MANURE ADDED x * ° XX °
X* * 5.2° ° -
o
00
o o
* x °°
x ^
0 "x
° o o
/ «o° %^°*
1.00 2OO 3iOO 4.00 5.00 6.00 7.00
ELECTRICAL CONDUCTIVITY, mmhos/cm
8.00
Figure 27. Comparison of electrical conductivity versus NO -N collected from ceramic
samplers from manure plots treated in 1972.
-------
Table 23. ELECTRICAL CONDUCTIVITY (EC) OF SOIL SOLUTIONS TAKEN USING
POROUS CERAMIC CUPS INSTALLED AT 106 cm DEPTHS. HULLINGER
FARM, VERNAL, UTAH, 1972.
Manure Rate
Dry Weight
Control
54 mt/ha
108 mt/ha
216 mt/ha
Date of
Sample
7-14
7-22
7-28
8-4
8-10
8-19
8-23
9-7
9-18
7-14
7-22
7-28
8-4
8-10
8-19
8-23
9-7
9-18
7-14
7-22
7-28
8-4
8-10
8-19
8-23
9-7
9-18
7-14
7-22
7-28
8-4
8-10
8-19
8-23
9-7
9-18
Crop Grown
Sudan Grass
(mmho/cm)
3.1a
2.6
3.6a
4.1a
4.1
4.1
3.7
4.1
4.1
3.7
3.4
4.1
4.2a
6.6a
4.6
4.8
4.8
4.9
4.8a
4.0
4.1
4.9a
4.1
4.0
4.2
5.5
3.9a
3.9a
4.3
4.5
4.6
5.4a
4.6
Corn
(mmho/cm)
3.6a
2.8
3.4
3.4a
3.9
3.8
4.1
4.0
4.1
3.8
3.9
3.0a
3.4
4.0
4.0
4.2
4.1
4.1
2.7a
2.8
4.1a
3.6
4.0
4.4
5.1a
3.9a
5.2a
2.03
2.9
3.9a
4.7
4.6
4.9
6.2
5.0a
6.2
Solution extracts from only two or fewer reps could be obtained for
analysis.
86
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Barrel Lysimeters
The data for N03-N in the barrels in 1972 are shown in Table 24 (see
also Table B-26). High irrigation rates were used so that all of the
barrels, except the four drained barrels, were waterlogged sufficiently
that corn growth was severely stunted. The barrels received irrigation
water by the same schedule as the manure plots discussed in the fore-
going .
Higher N03-N values were measured under commercial fertilizer
applications than the manure treatments. There were much higher
values of nitrate measured in the 440 Kg/ha Ca(NC>3)2 barrels than 100
Kg/ha and the 110 Kg/ha rate was higher than the check treatment.
The barrels having drains with 440 Kg/ha - Ca(N03)2 had slightly higher
nitrate values than the waterlogged barrels. Where Ca(N03)2 fertilizer
was used, denitrification seems to have occurred in the early part of
August in the undrained and drained barrels but the N03-N level seems
to remain constant after that time. The drained barrels may have had
leaching losses. Barrels with higher fertilizer additions did not
decrease in NQ3-N levels to the NOj-N levels obtained in barrels with
lower fertilizer rates. This suggests that the N03-N reduction was
limited by conditions other than N03-N content (possibly by organic
carbon availability in the deeper depths).
A very different effect is observed in the manure application data
(Table 24). The large source of readily soluble and mobile organic
carbon permitted maximum denitrification to occur in the waterlogged
barrels. The N03-N decreased with increasing manure application
levels. Soils with rates of 216 mt/ha added had less than a third as
much N03-N as when only 54 mt/ha was added. In contrast, the drained
soils having 216 mt/ha of manure added, apparently had less denitrifi-
cation losses and had high levels of N03-N. The ratio of N03-N in the
drained soil to N03-N in waterlogged soil by weekly intervals was 1.2,
1.1, 1.5, 5.3, 7.6, 24.3, 24.3, and 7.0. Early N03-N levels before
waterlogging developed extensively might be expected to be similar.
The higher the rate of manure added, the lower the soluble N03-N
extracted in early weeks. This is probably a result of conversion to
soluble N03 by organic synthesis.
At the beginning of the 1973 season, drains were installed In all
barrels. Also there was much less irrigation applied in 1973 than
1972. The barrels had a much lower water content, were not waterlogged
and had better corn growth.. However, the soil water content was so low
that it was impossible to get soil water samples from the ceramic
samplers except in. a few cases (Table B-27 Appendix B). The available
data show very little N03-N in the manure treated barrels that had
been waterlogged in 1972. This indicates that denitrification had
been nearly complete under the waterlogged conditions of 1972. No
new additions of nitrogen, either as commercial fertilizer or manure,
were made to the barrels in 1973. Table B-28 in Appendix B gives
results of EC measurements on water samples from barrels.
87
-------
Table 24. N03-N MEASUREMENTS MADE IN THE BARRELS.3
(ppm)
Ca(N03)2
kg/ha
Date
7-13-72
7-22
7-28
8-1
8-10
8-18
8-23
9-6
9-20
Average 1972
6-21-73
6-30
7-16
7-30
8-8
8-23
9-5
Average 1973
Check
117
116
103
73
99
87
80
69
43
87
11
20
17
27
19
110
65
167
308
174
123
105
110
136
84
141
23
49
22
1
7
20
440
- 1 Q79
283
198
292
380
256
306
312
273
225
280
224
185
158
169
55
158
440
44
403
330
620
410
158
328
328
__^,
54
75
81
102
92
53
80
69
63
39
73
10
14
17
13
14
Manure
mt/ha
108
59
58
67
83
76
71
63
54
32
62
5
6
1
4
216
24
33
34
27
26
21
15
10
1
21
1
1
1
28
54
27
19
216D
38
38
40
138
159
364
243
146
280
301
226
183
44
207
aSamples were taken at about 70 cm from the soil surface from ceramic
samplers. D refers to barrels that had drains. The barrels were
planted to corn and treated only in 1972.
88
-------
Yields
Only limited yield data were taken from the large plots (0.17 hectare)
of this study because it was apparent that there were generally little
differences in yield due to treatment. In 1972, corn was planted so
late that it did not mature and was harvested for silage only. In 1973,
corn was planted and matured normally which resulted in grain yields
as shown in Table 25. The data indicate no influence of treatment
on yields.
Table 26 shows the yields from the manure plots in 1972 and 1973. The
data show a small increase in yield as the manure rate increased to
108 mt/ha. The yields of both corn and sudan grass where treatments
were imposed the same year were depressed by the high manure rate.
However, there was apparently a beneficial effect of the high manure
treatment the following year. Thus, these data would indicate no
harmful effect on yield of manure treatments up to about 100 mt/ha of
manure.
Summary
In many areas of the western United States, irrigation practices
significantly influence the quantity and quality of irrigation return
flow. In the Colorado River Basin, salinity (total dissolved solids)
is recognized as the most serious water quality problem. The research
covered by this report involved study of the degree of control of
return flow which is possible through management on the farm of
irrigation, drainage, and fertilizer application practices. The
project included field, laboratory and computer modeling work.
Most of the field work was conducted on the Hullinger Farm near Vernal,
Utah. The farm had a solid-set sprinkler system and a subsurface
drainage system. Large plots (30 by 55 m) were treated with applications
of nitrogen fertilizer (0, 110, and 440 kg/ha). Different irrigation
treatments were applied to these plots and salt and nitrate movements
were studied. Both alfalfa and corn were grown.
Effects of irrigation management on salt movements were evaluated from
measurements of EC of the drain effluent and the soil solution above
the water table. In 1972, the corn was irrigated to insure downward
movement of water through, the root zone. Application rates were used
on the corn of 1.1 and 1.5 times ET which was measured by lysimeters
containing alfalfa. In 1973 the corn plots were irrigated whenever the
soil moisture, deer eased to a predetermined level. The total depth of
irrigation water was much less in 1973 than 1972. Although the average
EC of irrigation water and drain effluent for any drain was essentially
the same for 1972 and 1973, the total salt discharged was greater for
1973. This is because the drain flow was greater in 1973 than 1972.
This greater drain flow occurred even with considerably less application
of irrigation water on the farm. Measurements of groundwater gradients
confirmed that groundwater moved to the drains from outside the farm
89
-------
Table 25. GRAIN YIELDS FROM CORN IN 1973 AS INFLUENCED BY COMMERCIAL
FERTILIZER TREATMENT.
Plot Treatment
Corn Grain Yield (17% Moisture)
kg/ha
5N
5M
5S
SAN
SAM
5AS
6N, 6M, 6S
6840
7150
7150
7150
7460
7150
6840
Table 26. YIELDS OF CORN AND SUDAN GRASS IN 1972 AND CORN IN 1973 ON
THE MANURE PLOTS. YIELDS ARE IN FRESH WEIGHTS.
Manure Treatment
1972 Corn
1972 Sudan Grass
1973 Corn
(retreated)
1973 Corn
Check
47.1
49.9
54.3
46.8
54
48.1
53.8
52.9
55.2
108
(mt/ha)
50.2
51.2
56.6
55.4
216
46.5
44.6
42.9
56.6
90
-------
boundaries. The drain discharge was relatively insensitive to irrigation
management on the farm and depended upon practices of farmers over a
much larger area. Thus any irrigation management plan for return
flow quality control must include the major part of a hydrologic unit
in order to be successful.
In general, the higher values of drain effluent EC were associated
with infrequent small flows where the average water table was deeper.
This result indicates salt storage above the water table. It is
very likely that storage has been going on for long periods of time
and is not directly a result of irrigation management practiced since
research work began on the Hullinger farm (1970).
The EC of water samples collected from ceramic cups above the water
table was higher than for drain effluent. Thus, the general ground-
water was of better quality than the soil profile discharge from the
farm. Water table depth appears to be an important factor on storage
of salt in the soil profile.
The total seasonal salt discharge was directly related to the quantity
of water discharged by the drains. Therefore management of water is
the key to successful return flow quality management. Any control
plan which will reduce total discharge of water will probably also
reduce total discharge of salts, at least over the short term. The
period of effectiveness of such a plan is difficult to ascertain.
Field trials for detailed study of salt movements were conducted at
three sites (Vernal, Farmington and Logan) having different soils.
Water of various qualities (EC ranging from about 1 to 10 mmho/cm)
was added to small areas and its movement through the soil profile
was monitored. Addition of large amounts of water to the soil
surface had little effect on the soil solution EC. Results indicate
large "buffering" within the soil suggesting that considerable precipi-
tation and solution of salts were occurring. Monitoring soil solution
EC with vertical four-probe, horizontal four-probe, and samples
extracted through ceramic cups showed the three methods to give reason-
ably comparable results.
Laboratory studies on the soil from the Hullinger farm also indicated
the existence of high "buffering" capacity. This soil contains a
complex mixture of salts haying different source strengths and
solubilities. Large quantities of relatively low solubility salts
were shown to exist.
Computer models for simultaneous salt and moisture flow were modified to
better describe salt movements. Diffusion and dis.pers.ion were included.
Numerical procedures were modified to eliminate "numerical dispersion."
Root growth and' seasonal changes in rooting depth with time were
included. Methods were developed to estimate crop yield based upon
relative transpiration. The model was modified to allow for variation
of the relative proportion of potential transpiration to potential
91
-------
evapotranspiration over the season. Variations in evapotranspiration
during a 24-hour day were included. Predictions of relative yield
made for many different management possibilities indicated that yield
decreases would not occur until several years later because of slow
salt buildup. The predictions were highly dependent on the root depth
because of the presence of water. Several management possibilities
that allow salt storage in the profile for several years (no leaching)
were shown with little yield decrease. However, some leaching will
eventually be needed.
Nitrate movements were studied beneath large plots (30 by 55 m) which
were treated with applications of commercial fertilizer, smaller
plots (6 by 12 m) treated with dairy manure, and barrel lysimeters
treated with both commercial fertilizer and manure. Soil samples from
the large plots indicated more N03-N in the corn plots than the alfalfa
plots at the end of each season. Samples withdrawn from ceramic cups
in the soil profile also showed this result.
Results of N03-N measurements from tile drain effluent were masked by
the encroachment of groundwater from outside the farm boundaries. One
of the control drains (overlying plot received no application of nitrate)
had N03-N concentrations as great or greater than drains beneath two of
the plots receiving 440 kg/ha application of fertilizer.
One drain was successfully submerged so that the water table was always
at or above the top of the gravel envelope during the irrigation
season. The NOa-N concentration of effluent from this drain was
significantly lower than for the drain receiving the same fertilizer
application but flowing freely and having air within the drain pipe.
Soil samples from the manure plots indicated that prior to application
of manure, the residual nitrate level was low. In 1972 plots were
treated with manure and duplicate sets of plots were planted to corn
and Sudan grass. In 1973, those plots with sudan grass the previous
year received additional treatments of manure while those planted to
corn the previous year received no additional manure. Corn was used
on all cropped plots in 1973. During 1973, the plots with two
consecutive years of manure application had almost identical N03-N
concentrations and distributions in the profile as the plots receiving
only one application of manure. Concentrations of NOa-N did not drop
appreciably during the second year after manure application in spite of
appreciable crop removal of N the first year. Even a second year's
application of manure did not buildup the NQ3-N concentrations
noticeably.
Salt concentrations in soil solution, extracted from the manure plots
indicated that leaching should be done periodically when large
quantities of manure are added to the soil. The yields of both corn
and Sudan grass where treatments were imposed the same year were
depressed by the high manure rate. However, there apparently was a
beneficial effect of the high manure treatment the following year.
92
-------
Thus, the results indicated no hatful effect on yield of manure
treatments up to about 100 mt/ha.
In 1972 the barrel lysimeters without drains were waterlogged
sufficiently to severely stunt growth of corn. The N03~N concentrations
extracted from the bottom of the barrels were higher for the
commercial fertilizer treatments than the manure treatments. Denitri-
fication was probably limited by supply of carbon in the commercial
fertilizer treated barrels while the manure may have supplied carbon
for more complete denitrification.
93
-------
SECTION VI
REFERENCES
Barnes, H. E. 1954. Electrical subsurface exploration simplified.
Roads and Streets. May. 97:81-84.
Bernstein, L. and L. E. Francois. 1973. Leaching requirement studies:
Sensitivity of alfalfa to salinity of irrigation and drainage
waters. Soil Science Soc. Amer. Proc. 37:931-943.
Bremner, J. M. 1965. Inorganic forms of nitrogen, p. 1179-1237. In
C. A. Black (Ed.). Methods of Soil Analysis, Part 2. No. 9 in
the Series - Agronomy. Amer. Soc. Agron., Inc., Madison, Wise.
Bresler, E. 1973. Simultaneous transport of solute and water under
transient unsaturated flow conditions. Water Resources Research
9(4):975-986.
Dutt, G. R., M. J. Shaffer, and W. J. Moore. 1972. Computer simulation
model of dynamic bio-physiochemical processes in soils. Ariz.
Agr. Expt. Sta. Tech. Bull. 196. 101 pp.
Griffin, R. A. and J. J. Jurinak. 1973. Estimation of activity
coefficients from the electrical conductivity of natural aquatic
systems and soil extracts. Soil Sci. 116:26-32.
Gupta, S. C. 1972. Salt flow in soils as influenced by water flow,
root extraction and exchange. Ph.D. Dissertation. Utah State
University, Logan, Utah 112 pp.
Gupta, S. C. and R. J. Hanks. 1972. Influence of water content on
electrical conductivity of the soil. Soil Sci. Soc. Amer. Proc.
36:855-857.
Hanks, R. J. 1974. Model for predicting plant yield as influenced by
water use. Agron. Journ. 66:660-664.
King, L. G. and R. J. Hanks. 1973. Irrigation management for control
of quality and irrigation return, flow. EPA-R2-73-265, U.S.
Environmental Protection Agency, Washington, D. C.
Nimah, M. N. and R. J. Hanks. 1973a. Model for estimating soil water
and atmos.ph.eric interrelations: I. Description and sensitivity.
Soil Sci. Soc. Amer. 37:528-532.
Nimah, M. N. and R. J. Hanks. 19_73b. Model for estimating soil water
and atmospheric interrelations: II. Field test of the model.
Soil Sci. Soc. Amer. Proc. 37:528-532.
94
-------
Sabti, N. A. 1974. Field evaluation of transient drainage during the
irrigation season. M.S. Thesis, Utah State University, Logan.
146 p.
U. S. Environmental Protection Agency. 1971. The mineral quality
problem in the Colorado River Basin. Summary Report, U.S.
Environmental Protection Agency Regions 8 and 9, GPO 790485. 65 p.
Wright J. L. and M. E. Jensen. 1972. Peak water requirements of crops
in south Idaho. Jour. Irr. and Drain. Div., Proc. Amer. Soc. Civ.
Eng. IR2:193-201
95
-------
SECTION VII
PUBLICATIONS
Childs, S. W. 1974. A model to predict the effect of salinity of crop
growth.. M.S. Thesis, Utah State University, Logan. 98 p.
Hanks, R. J., J. C. Andersen, L. G. King, S. W. Childs, and J. R.
Cannon. 1974. An evaluation of farm irrigation practices as a
means to control the water quality of return flow. Utah Agr.
Exp. Sta. Res. Report 19. 48 p.
Hanks, R. J., L. G. King, and S. W. Childs. Model to predict water and
salt flow under irrigated conditions (manuscript in preparation).
Hunsaker, V. E., R. W. Miller, J. D. Melamed, L. G. King, and R. J. Hanks.
Nitrate accumulation and movement under manure loading and
fertilizer additions (manuscript in preparation.)
Maxwell, D. D. Computer solution for drainage of sloping lands. M.S.
Thesis (In preparation partially supported by this project).
Melamed, J. D. Irrigation management affected by salinity and water
availability. Ph.D. Dissertation. (in preparation).
Natur, F. S. 1974. Finite difference solution for drainage of hetero-
geneous sloping lands. Ph.D. Dissertation. Utah State University,
Logan, (partial support from this project). 167 p.
Sabti, N. A. 1974. Field evaluation of transient drainage during the
irrigation season. M.S. Thesis, Utah State University, Logan
(partial support from this project). 146 p.
96
-------
SECTION VIII
APPENDICES
A. FORTRAN Listing of Computer Model
B. Field Data
97
-------
APPENDIX A
FORTRAN Listing of Computer Model
i c nr NUHPfp OF jo*"; TO *F RUN
1 C *LM-1 IF rAME BATTC SOIL DATA IS USED for ALL JOP":
"5 C fILMrti IF '"OIL 13 niFFERENT FPR DIFFERENT JOHS
= NUHprs OF ENTRIES IN T»ir WATER CONTENT- POTENTIAL TA«LE NOTE-
11 C YCU NEED ENTRIES FOR WATER CONTENT CF 7r"0 AN" CN<" AH"VF WATH
1' C KltKftKA CONTROL OUTPUT ""x . - KIrl CIVTS l>r',V\.1r, AT rnUNnA?Y CONDITIONS
13 c rx. - KP=? civFc THANHS HT rruwrARt COMPTTIONS
!» C TPTPKT.K5 Civr SPrCIAL OUTPUT FOR PRCCRA* C«rrKI««?
15 C ALAM8A.niFO.nTFA.niFH AR>- SALT LO Cr PAPAMnr"':
1C C F= HYOPA'JLIC rONHUCTIVITY ARRAY
17 c KILL: i rurppEssrs PRTNTINO OF INPUT DATA
It C V- RCUNPAOY CONOITION ARRAY CTVEN «S FLUX.TI"'' T" TND. FLUX .T T«C TO
1-3 C T'lOtfTC. * FLUX IS IRRIGATION OR t>ATN. - FLUX IS rT TTENTIAL
TO C STr POUNP*RY CONDITION ARRAY FOR SALT COVtrHT^ATTON OF HATC*
ri C HP: DEPTH INCREMENT ARRA"V
rr c PPFSAVT 'JOOT OENSTTY rUNrTion ART«Y AS OFCI^AL FRACTTHM OF ROOTS PER DEPTH
:i C Pr HATRTT POTENTIAL ARRAY
;* C SLX= DATA nEAPIN OPTIONS FOB WJLTTPLE JOT rUN--
r«i C Sf«AX: SCALER FOR TALT CONTENT IN PLOT SU1"OUTTNF
rc c «rri>AY: NUHICR or DAYS FOR orvELPPHENT or KATURF root PPPFILT
:7 C PtTOEL: KUH3FR 3F COMPUTATION INCPEHE'IT^ I': PTOT nROWT H LPOP
?5 C PDROCT: OTPTH OF NATURE ROOT PROFTLE - USUALLY PPJKKJ
20 C SALTAr MULTIPLIER FOR SALT CONTENT VALUES TO CHA1T U»!ITS
:ij C ETTAPTr DAYS FROM TINT TO START OF COVER CrCUTM
51 C F*0 OF COMPUTATION
«D C RPTS- RPOT nrt:iST'KCE
>i c KPP.Y is pREssimr or LOWEST PPSSIPLF KATE^ OHNTFNT
N; c MWET ri PRESSURE: or HicHf^T POSSTPLF WATER CPHTFNT
«» C UATL TS LnMEST POSSIPLE UATER CONTENT
«m C WITH IS MIGHEST POSSlnLf WATTR CPHTFKT
«.<; c HLOW is THE MINIMUM ROOT POTENTIAL ALLOWED
>»< C HHI IS T'«r HAXIMTM ROOT POTENTIAL ALLOWED
17 C PP PEPRfTHTS PLANT UPTAKT AOOITIONS
«-, C CWFrCUKULATIVE WATER FLOW
H«l C SCMr SALT FLOW ACIDS': LOWER BOUNtHRY
:t C WFROO AND WFDO »PF ^t'RFAC^ WATER FLOW PATFS CrcPUTfP T WP
51 C CUMS-CumiLATTVE WATER FLOW AT THE SURFACE
SI C CUKB= CUMULATIVE WATER FLOW AT THE POTTO*
53 C SALT= TOTAL SALT TN THE PROFILE
5« C H»OOT: ROOT WATER POTTNTIAL
f:, C » IS WATT" PPESSURE AS A FUNCTION OF DEPTH "TlnNlM" AT TOP
56 C W IS WATFi* CONTENT AS A FUNCTION OF DEPTH EECT'MSlNr AT TOP
98
-------
f>7 C rTPL IS TMC
5.1 C rT IS THE rofNTTHL C V4PCTR AN <;P IR AT-'ON. AL U»YT wri"ATTV
:_- r««»««»rQ.H,r'iY 'w-RPF* *(SF< *',' ^'ARRAYS »^r OF r,A«r ri^1"',": I^N*. AT
CL C*»»»*«T «TET' V AF!R»Y-> ASF Of TAMC DTlrN$TOMS AT LTaSTrTr?
ci c»»»«««r>ctT'«Pr or CSOAL DTMrH-;ioN<;.:co AT MOCT
L: C ----- TAA=1, FOR ?rKO FLUX AT rOTTOWtTftfUC FQI? H«KK> CrNSTAHT A 5
17 C ----- K IS NO. OF DELX INCR THFNTS i» M NP . OT TIMT-i M«U ^"TNTrOf KTT NO.OT A 12
CI PTMFNSTON R!1F<: AV< ?5 1. POOT ( 25 I
f 0 TIMfNSTON DO(?5)»H<25 ) .G ( 75 > . Yl 25) i W(75) «RCr «?
CS riMENSTON SFJEO) iTETCESI tVI35l
£7 niHENSTON S 5 ( 25 ) t SO (? 5) . C« 25 » .B ( 251 . Fl 251
IS THMrNSTON P«125)t1(12S» .F (125 » . T< 125 ) »OATF« TO)
El
7C
71 II
7: KK-K«1
7H P FAD IS .?71)ALAMBA,DIFO»mFA.OIFB»OrLU»COHH
7C "FAD 271» (VI II
77
au PTAOIS .271) (P1T).T=1.ND»
31 PFADI5«271IIEII)tI=ltNDt
F' Tr(KlLL. 5.1)00 TO 1500
CI V7TTEJ6.777)
;:"* UPITC <6t?ea) K.MM.IF p.NB.NDt
?". 150C T(l)ro.
So 1 !!> = ( tl !) IPt2)-PJ 1) J>
57 rniG I = 2tl«D
f 3 " (I)rEI T) IP«II-PII-1 11*0(1-11
9<3 1R T«T)rOCLW»T CI-1J
?L 7FIKILL.F5.1IGO TO 1T (I) .PC I) .E 1 1 ) f 0 ( T I .T (NE+H .P IN" «T I trINF+I
25 11 TFILMM.rO. 01 (50 TO 2?
9c- T<"jm_.!:o.i.oa.w_H.r a.ci no TO 23
97 "FADis.rc?) MLX.KILL
23 TADI5»r»nATE
1G TF(«LX.r0.1.0R.MLX.E0.1IRFAD(5t?71MV(T).T3 .TFPJ
ILL TF(MLX.FQ.2.0R.MLX.FQ ..I=liKK>
II? ?3 LHHrLHM*l ' CC0790CO
,L3 K?rl C0079C10
If» PrAD 271. (WtD.I-l.KK)
!CS TAD 271. (SFdlt T = 1>KKI
'LC TiD ?71f DfTT.CONa.TAA.TTME.TT.CUflT.RRFS
1C7 TAD 271. HD^Y.HWFT,HATL.W»TM.m.O«. «"I. SHAX U0062GCO
1L» f!rAD(5 . 771 JROFDAY. RDF DEL.SALTA.CS TAPTtEST OF. AK1.AK2
IL2 AK«irO. 5/RPFDAY
lib nrLDArzRDFDAY*2'l./RDFnEL
111 rTDA
liT HPOOTrMLOU
99
-------
nr,-
11 G "FLTrDFTT
117 T«=1.0-TT
113 TP8=1.G-TAA
11 3 rHAXiWATH
iro RUNOFrO.O
121 CUNS=0.
\~2 »«YTIf1E=n
1C 3 *>"I-D.
1T7 5-CMrn.
U?
J=CU(U-T(ll)/OEtV«l.n
H(1» = (PC J»1)-PIJI » (W (1I-TIJJ »/OCLU*P(J)
lit C(l»=OELtf/«PCJ*ll-PCJ II
1?!; 00 ?T TrTtK
l.C 22 ^IT
'.?7 DO
13S
1"0 HIT 1 = 1 PI J»1)-PU) >« lwn>-TIJ»/OCL«*riJI
ita cn»=o[:Lii/(p{j«ii-pij it
112 WITCI6.
1 I«0.5»S*L7A
irc 10 rci»=w«n
HI TF|KILL.n.OIWRITri6t?86l
H: c
153 C CPVEr GROWTH LOOP
'.5 » C
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ITS !>0 31 T:2ttERt2
ITT T«!=I/?
It 3 Tf«L'1«.NF.l.ANO.I«t.X.Nr.l.ANO.n.)t.«C.%l CO TC '1
1T-3 IF(V(I-1 I .CC.C.CI CO TO 31
Iti. TF((1LX.F,1.3IV(I-1 irTFTIIRI
iri TFTCIIirVII-l I
T2 TF(VCri/?*..LT.f:^T»RT I GO TO 1003
H t V(I-l|;TFT(IRI-TrT«IR|.AKl/(l.*EXPf 6.-AK5.IVCI I- F5TA "T .2*. I I I
!C* 6P TO 31
115 10C3 VlT-UrTFTdR)
1C i 31 TF(KlLL.C3.0IWRITtl6tr7IHV«II .VCT-ll tTCTlfl .TFIIll
167 WFOD^VIll
17U IFIKILL.E0.1IGO TO 31(10
100
-------
171 URTTEI6.789)
'77 W'RlTEt »27m DrT'
173 WRITE (E.^fljl
17K WPITEJ G.?7i|)HrRY.HUET .UATL. WATH.HLO U'.HHT. DCL U
17' W*ITriE.23H)
173 VPITE{E.27ni"SAV(J)« IROO T t J ) -DD< T-l J J/ IROOTf J I-POOT CJ-1 II «FT>F(II
1?? TFCPOOTIJ-ll.CT.rrH I-11 I RDriilt 10 CO 2 DOF( I> r(On(Il-DO(T-l) )/(ROO T« Jl-POO T( J-l I I .RDFSAVIJI "DF «I I
-i,* TMSOOTI J-ii.cT.not i-ii» noFi7)=nnF(3»-inotT«j-i>-nrur-iM/trnoT u
-L'S 1I-T!OOT(J-1I XROF^AVtJ I
7LG TF(ROOTIJ>.GT.OO
-------
J-/DO C I
?ur' IFU»BStl.l.EOR-ER>-ABS«D.l»EOR>I.LF.O.OI CO TO >?
"»6 'FIKCK.ra.H CO TO 55
"*7 TriKCK.LT.l?) GO TO 5 n
7112 -2 l|ll»=«COR»OOI2l/3IH*H»?|»TT-eil»»TM»6l2l»TM-PDI?ll/rr
"»» TFIHJ1I.LT.HORYI HIllrHCRV
""J TF (Hdl.GT.Htrm MIllrHWFT
-ti rp TO 7?
-r? 55 HdjrHKP
"I" WI1»=UKP
T.» KCK=KCK+l
?&5 rr TO IT
'1C S3 KCK=KCK»1
'- 7 IT fER-rOPI Gl.72.6*
"5J 61 IFMU(l»-W»THI.CC.O.n» GO TO 72
":! P"TrH(U
"fC. U(ll=fUllt*TOPI*0.5
^*ci rn TO C7
"*£" C< IF(«tf(ll-U»TL».Lr.O.CI CO TO 72
67 J-IU(ll-TIUI/DrLU*1.0
B?=IIM1)-TU» )/Drm
TFI*BSiron-C.).LT.1.0E-OC» GO TO 72
"n 70 Tuu=iuiii*rF.LW/IPIJ+ll-PCJII
3J 75 rCNTIKUC
3*
102
-------
res c
-<<<; C NFW T-POT WHEN TACTUAL T<; LESS THAU F-POT
"37 C
?8a FTPLrET
TFIFT.CF.D.) GO TO 39
TF(F03.CT.O.) Go TO Z ZZ
TF»TI«r/799 CO TO 365
'33 1U01 FTPL = CT-tOR
1LU ir«ABS(ETPL-0.).LT.1.0E-i|) GO TO 19
T 1 3&rj HHOLD-HDOOT
T(j2 IFtIRTPRT.Ea.l.OR.IRTPRT.F(J.?l«RTTE«6,271lrT.«"R.rORt FT WLT.ETPL
3f,3 C
^H C COMMUTATION OF ROOT SINK FUNCTION
7C5 C
'DC rlKKrQ.O
tL3 r1? 219 I-TtK
-13 213 FtUrGtH-;&.«SE(I)-OOII»«RRfS
TICI LCNTrQ
'11 11'
DC *?Q I=2tK
TFtHrooT-rti) .GT.n. ) no TO
SINK=SINK»PtU»RPFt II !: I T )
-11 t»20
719 ircnSINK.NE.C.I GO TO 110
32U IFtHr!OOT.r3.HLOH> GO TO HQZ
321 HPCOT-HLOW
72? TO TC 11?
323 110 TFIDSINK.ra.DSAvr 1 GO TO 102
-21 HPOOT=SINK/OSINK
725 IFIHRCOT.LT.HLOU) HROOT-HLOU
^27 IF GO TO 112
723 URITF.C6t1?2)
T^3 122 FCRHATI" LCNT.F.Q .20* I
721 DO IPS I = 7tK
13- rF(HROOT-F«I).GT.O. IPO TO 107
333 *(T)r3(T)«2.»ROFIII»IHnoOT-ECin/«DOfr*l»-tr fT -1 1 J
;;H r;INK-STNK»RDFlIJ»3«I> ( H100 T-EI I» 1
-rj5 PO TO 1C6
73 G 107 »
-------
3*2 C
343 C UATFS FLOW TRIDIAOONAL MATRIX SOLUTION
T44 C
3*5 106 TO 118 I=?»K
346 PPTrrDD(T»l)-DDII-lM/(3.n»OELTI 6160
3^7 DLXA=inn«r>-Doei-i) i e iei
348 DLXn=JDC(I*l)-DO(TlJ B 162
349 PB:CII)»rOT/TT»Bf I) /TLXD+tH T-ll/DLX* B 1621
350 HAricin.POT'Gin *CB« TI/OLXB)»ITM*((!IT»1)-GI II I-DLXBH HI fT-l)/DLXA B 1622
351 1) ITM«IGII-1J-G(TH +OLXA ) **II I* «DO( I»l» -00 (I -1 » J»O.S V Tf
35T IFII.GT.r.U) GO TO 115
353 If(Hill.PF.HWET.OR.IH1I.LE.HDRYI GO TO 109
754 DArDA-U9tI-l)/OLXA). !TH« 1C II-ll-GC Tl I+OL X»> )/TT*COR /T T
355 PR=rB-6CT-l»/DLX»
756 CO TO 112
357 109 ntG(l) tG 12) t OTLTf TOR >E R< KCK
393 381 FQRHATC '9E10.4tI3)
394 GC TO 179
795 134 Hll)=(EOOD(2)/B(l)»HI2)*TT-Gll)«Tn*CI2)*TH*OOC2)l/TT
336 IFCIRTPRT.NE.6IGO TO 382
397 HRITEI6t333l
398 383 FORMAT{* AFTER 134*I
104
-------
333 WRITEI6t3?UTIMEtUFOniH(lltHC2)tG!lt tGC2I.CELT.rORiEr?i KCK
400 332 IF(H(1).LT.HDRYI HC1)=HDRY
401 IF CHI1I.GT.HUETI HU )=HVfT
4C2 13-3 1-1
403 1*2 IF»ABS»HII)-G»SUM2 A 329
431 IF(ABSISUM1-SUH2>.LE.ABS(SUH3» GO TO 172
432 SUH3=SUH1-SUM2
433 172 CONTINUE
434 iriABS«SUM3I.LE.ABStCON8)I 60 TO 175
435 IFIOELT.LE.OETT.O.ll GO TO 175
436 DFLT=0.5*DELT
437 CO TO 106
433 175 SUMl=0.n
439 SUM2=0.0
440 DO 178 I=?tK
441 SUMl=uJII»inDCI»l)-OP(I-l>»/2.+SUMl
442 178 SUH?=YCri.lDD(I*lJ-DDtl-l»l/2.»SUM2
443 CWF=SUM1-PIT
4*4 UFRDD:eSUMl-<:UH2>/DELT
4*5 UFUUrBCNPI»l(HtN?)-H{NB+l>) »TT*l
**6 1/IDOINP»1I-OOINB)I
4*7 CUMS=urOn»OELT»C!JHS A 341
4*8 Ct!MB=WFUU»DELT + CUHB
4*9 SUMA=SUHA»SINK»nrLT
450 CTRAN=CTRAN»ETPL»OELT
*51 CWFLX=ISU«1-SUH2> A343A
*52 KB=K-1
*53 IFIEOR.GE.O.»RPI=RPI+COR«DELT
*5* C
455 C SALT LOOP 00362000
105
-------
456 C
457 VFRU=BI1>»IIHI1>-II(ZI |»TT 1 1 G< 11-6 12) I*TM+ 00( 2» I/DD 12 I
53 TF(WFPU.LT.Q. IUFRU-0.
453 ALFArO.G 0037700C
460 WATU=(Y(l)«T«»W(l>»TT*Y(?»»T*+WI2>*TTI/2.
461 T3 21* T-TtK
462 PLXAUDDf TI-Drtl-lM
463 PLXB=tDDIT*l»-DD( Tl »
464 DLXC=«PD(I»lt-ODJ T-ll 1*0.5
465 VFRD:B(II*IIH(I»-H( I* II) «TT + CCI II -GC 1*11 I T?1«DLXB I/OLXB
466 U»TO = ( YIT1«TH»U(I)»TT+Y(I»1 >«T^*«eT»l»»TT) /? .0
PFTArOIFO»DIF»»rXP«DIFB«UATOJ»»L»f>n»»»BSI«rRC/UATDl
TW=DEL7»(UCI>-Y(I)I *l WFRP*WFRUI/I 8.« ( Wt I)»T( I) I)
AXrTU«UFno/IOLXA»ttATU>«ALFA/DLXA«VFRU»0.5
«70 IFII.EQ.?IAXrUFRU
»72 POrWCI»«OLXC/ITT»nELT l-AX»2.»ALF»/nLX»»CX4UFRO
173 PA:lT(II»SSIII*OLXC/OfLT*TI1«UX»ISSII-l»-SSIIII*l(FRU«SSCI>-CX»fSSI
»7« 1I1-SSCI»1H-UFRD.SS«IIJI/TT
»75 IFJI.CT.21GO TO 158
477 Bn-3E+AX-?.»ALFA/nLXA
«78 FII)rOA/BT
479 nil=CX/BB
480 GO TO 217
481 188 IFd.GC.KI 60 TO 183
482 f III=CX/(PB-AX»EIT-1I I
483 F (I)r(n»«AX»F(I-l » /« 9B-AX.EII-1) I
494 213 ALFA=BETA
485 UATU=UATD
486 IF(Xr.EQ.3)URITt(6»27-TU/«UCI-l).«nOIII-OD(T-2M.0.5»
5C4 SE(TJ=SEtI«ll
?C5 CO TO 191
5CC 192 TUrlSEd-n-SECIl )«! I)»-oo(ii i*o«si
508 sr«U=SEII-l>
S09 191 CONTINUE
510 SOIl)=Sr(ll*U(ll*0. 5*00(21
511 SALT=C.C 00403000
S12 SCM=WFRD««;S(K)*OEUT.SALTA»SCM
106
-------
*13 IFIVFRD.LT.O.1SCM=WFRD»CSS«KKI-SS(KI)»DELT«SALTA«SCH
51* DO 717 I=TtK
515 SOIIjrsrflj.udl.CDDr T«1I-DOCI-1»»»O.S«SALTA
516 217 SALT=SDII1«SALT
517 IF»EOR.LF.OI CO TO 220
518 FUNOF=CFO«?-WFDDI«nELT+fJUNOF A 3«e
519 220 TIHE=TIMC*DELT
520 IFIKI.NF.CI 60 TO 500
521 IFCKP.EO.n GO TO 500
522 IflLL.LT.MMI CO TO 2?3
523 C»LL PLOT IKKtWATH.WtnOilHAX.S0>
521 WHITE C6.?7«l (HI II .Irl.KKI
525 WRIT£t6»27m(<;EtII.IrltKK )
526 WRITEIGt27»»ir A(II.I=2>K)
527 WITE (6f?95»
528 LL=0 » 352
529 223 WRITE 16 . 555) TIME tCUF .SCM.WFOOtRUNOF .COHS fCUW «SUf»»i CTPAN.Wf ROD» S 00111000
530 lALTiHROOT
531 SCO IFUBSCSUH3-O.I.GT..0001) 60 TO 229 00*13000
532 226 nrLTr3.»DELT
533 CO TO 2i*l
83% 229 TV=ABStCONa»DrLT/SUH3)
535 23? IF(TW.GE,0.1«OETTI GO TO 235
536 TW=C.1»OCTT
537 PO TO 238
538 235 IF(TU.LE.1000.0*DETTI GO TO 238
539 TW=1000.G»OETT
5*0 238 IFITM.CT.2.0»OELTI GO TO ?26
S«tl DfLT=TW
5«2 C
513 C TfST TO SFE IF F.VAP OR RATN INTENSITY IEORI HAS CHANGED A 365
511 C
5*5 2%1 IFCIOELT.EQ.il OELTrPFLTl
516 IDELTrO
517 ir(OELT.LT.OCTT)DrLT:OETT
518 IFIOELT.GT.6.I DELT=6.
519 IFIABSCTIME-VtKC+1)I.GT.0.0001IGO TO 217
550 ir(KI.NF.O) GO TO 501 00125100
551 CALL PLOT CKKtWATHtWtPO.rMAX.SOl
552 Wr»ITE C6i27iO IH( II ,I = 1.KK1
SE3 WRITE(6i271l(SC(I)iI=lfKKI
551 ir(K5.E3.2ltmiTE(Ct26SIK6
555 KG=D
556 WRlTE'l6t295l
557 501 IFIKA. E0.01WRITE(6t55SITINE«CUFiSCMiUFOOiRUNOF>CUNS«CUHBtSUNAt CTPAOO132000
558 INtUFRDOfSALTtHROOT 001330CO
559 FCR=V«KC+2I
560 IR=IKC+2>/2
561 SFtllrSFCIR*!!
SS2 ET=TET(IR»1I
«!63 KCrKC»2
S61 HTIME=0
565 DCLTrOETT
566 GO TO 250
567 217 IFIITTHE»DELT1.LF.V(KC+1II GO TO 250
568 DtLT=VCKC»ll-TIME
569 250 LL=LL«1
1Q7
-------
570 C
S71 c CALCULATION CF HOURLY ET DEMAND FROM LYSINETFW B«T»
573 IFIVtKO.GT.C.) CO TO 2251
57* LTI«E=TTKr/2*
575 TIHELrLTTME
576 TIHEA=TTir/2*.-TIHEL
577 LTIHE=CTTNE*OELTI/2*
578 TIMrL=LTTf1C
573 TlHFD=TIHEC=2«.»»l.-TIICA»
591 EnRH20rVIKCI»TI«rC
532 IR=CKC«lirr
593 ETH?0=TFTIIRI»TT«CC
59» TIKELrTTHCC
595 IFITINEC.CE.i;.ITIHFL=12.
596 D«-MOMrCOSITIHCA.E.28321-COS«TWEL»6.2832/2*. )
597 257 rTNEW=(COSITIHEA«6.2832l-COS(TINEO»6.2832> l/PFNOf!
598 EORr£TNfU»EORH20/3ELT
599 FT=ETNEV«tTH20/DELT
6UO GO TO ?251
SOI 25* TFCTlHCn.CE.0.5160 TO 2253
602 DFLT1TDELT
603 TDELT=1
60* nCLTrll.-TIMEA)»2*.
605 2253 ETrO.
CC6 COR-0.
607 NTIHErr
6CS 2251 IFCrRTr!>T.E0.1.0R.IRTPRT.E8.»IHRITEI6.27*l TIMEtEOR.E Tt TTHEA»TTNE C
6C9 liTIMED.DfNOM.ETNTa
K10 IFCOELT.LT.DETTI OELTrQETT
611 IFCTIME-COKT.LT.-O.OOOH 60 TO 253
612 IFIttT.EQ.Q) CO TO *1
613 CALL PLOT (KKtVATHtUi OO.^HAXf SOI 0047LOCO
61* WRITE (6t27*l tH(n.I = l,KK) 00*71000
S15 tf«HTEI6t?7*HSE«IltI=liKKI 00*71010
616 *1 JFCIRTPRT.ME.5I GO TO *2
617 tf*=0.
613 S»=0.
619 DO ** I:2tK
ero s*=s»* SF (Ti. i non»i »-oo 11-111*0.5
621 ** «*=«*» H«T».10011*11-00(1-111.0.5
622 Dn*=DOIKKI-a.5»(DO(KKI-ODIKl*00(21-00(l)I
623 W«=U*/DO*
62* S*=S*/DD*
625 T*=SUHA/CTRAN
626 ET=CUF-CUHB»CUHS
108
-------
627 WRITEf E.^l
628 WHITEC C.^SJTinrtRPI.ET.SUMAt TH.CUMBiSCM.SEt KK ) tSq ,W 4
629 »2 IFCHL-LHMt2G7t267.15
630 15 IFlKLM.EQ.il CO TO 1*
631 GO TO 13
632 253 VCll=tWtll*YCll>«O.S
633 J=IYC11-TC1I>/DELW+1.0
63* EB=IY(1)-T|J|l/DfLW A 389
63S IFIABSIFOfl-O.OI.LT.O.COOU GO TO 256
636 CI1|T(P(J»l|-rCJ))«RP»P(Jt
637 255 CO T65 I=2tKK
638 JrJHlII-Tf1|>/DELW»1.0
639 BP=tmll-T«JM/OrLU
6*0 Gin = ip< j»u-ptjn»Be»p(j)
6*1 TK=tUm-Y(IM+WlII A 395
612 IFITU.GT.WATHI GO TO 259
6*3 IFITW.CE.UATL1 GO TO 262
64* TU=UATL
6*5 CO TO 262
6*6 259 TU=WATH
6*7 262 YCI>=UITI
6*8 UdlrTH A HQ2
6*9 S5«II=SECH
650 265 CONTINUE
651 SSIU=SEC11
652 60 TO 3*
653 267 CONTINUE
65* 263 STOP 00*71020
655 3 FORMATI*l't70»l»
656 *S FORMATC'O TIHC IRR » RAIN tt TP»N ACT YIEtD P
657 IRHIfJAGE STM INIT SALT FTMAt SALT AVE UATE
660 2S6 FORMATCO TIME FND SOIL FLUX ET FLUX SALT CONC. M CO*8Q010
661 27* FORMAT (11C12.5> 00«|710CO
662 555 FCRMATfl2Cll.il> 00*711CO
663 295 FORMAT t*o TIME CUF sen uroo RIN
66* 1 CUHS CUK9 TRANACT TRANPTT UFROD S«LT
665 2 HROOT'J
666 280 FCRHATt'O HATER POTENTIAL CONDUCTIVITY PIFFUSIVITY
667 1 WATFR POTENTIAL CONDUCTIVITY DIFFUSIVITY)
663 275 FORf1ATliriZ.5fl2X.1E12.SI
669 296 FORMATC'O DFPTH CCI) U-DEPTH H-OEPTH ROF-OEPTH
670 l" SE-OEPTHM
671 10012 FORHATt* ROFDAY ROFOEL ESTART ESTOP AK1
S72 1 AK2M
673 277 FORMATCOK MM IER NS ND KT KP KA IRTPRT'I
67* 289 FORMATI80H OETT CONO TAA TT«C TT
675 1 CUMT RRES)
676 283 FORHATC HORY HWET HATL WATH HLOW
677 1 HHI OELU'I
678 28* FORMAT!' ALAMBA SALTA OIFO DIFA DTFB' I
679 END
109
-------
APPENDIX B
FIELD DATA
Table B-l. Climatic data for 1972.
Date
6-24-72
6-25
6-25
6-27
6-28
6-29
6-30
7-1
7-2
7-3
7-4
7-5
7-6
7-7
7-8
7-9
7-10
7-11
7-12
7-13
7-14
7-15
7-16
7-17
7-18
7-19
7-20
7-21
7-21
7-23
7-24
7-25
7-26
7-27
7-28
7-29
7-30
7-31
8-1
Rs
(Ly/day)
569
690
690
678
724
710
712
667
667
667
733
745
547
627
636
598
598
675
620
619
651
701
701
701
613
592
521
672
565
561
561
561
576
426
582
634
634
634
580
Wind
(km/day)
185
140
140
190
78
76
95
132
132
132
110
95
105
138
105
135
135
113
109
78
109
93
93
93
97
161
174
177
117
97
97
97
82
88
90
103
103
103
100
Td
16
14
14
15
19
18
16
16
16
16
16
15
17
16
16
18
18
17
19
21
18
18
18
18
18
18
20
19
18
17
17
17
17
17
16
18
18
18
20
Tw
12
11
11
14
13
11
13
4
11
11
11
11
13
13
13
15
15
14
14
16
16
14
14
14
14
14
15
14
13
13
13
13
15
15
13
15
15
15
15
ET east
(cm)
-.49
.32
.33
.43
2.04
-.11
.16
.49
.49
.49
.11
.43
.16
.52
.52
.52
.52
-.67
.97
1.03
1.40
.72
.72
.72
.54
.92
1.08
.92
1.14
.63
.63
.63
.97
.53
.21
1.24
1.24
1.24
1.73
ET west
(cm)
0
-.65
-.65
2.70
.36
-1.46
.27
.54
.54
.54
.70
.54
.54
.81
.81
.81
.81
-.34
.92
.76
1.00
1.06
1.06
1.06
.92
1.24
1.13
1.08
.43
.74
.74
.74
.97
.48
.97
1.35
1.35
1.35
1.40
110
-------
Table B-l. Climatic data for 1972 (Continued).
Date
8-2
8-3
8-4
8-5
8-6
8-7
8-8
8-9
8-10
8-11
8-12
8-13
8-14
8-15
8-16
8-17
8-18
8-19
8-20
8-21
8-22
8-23
8-24
8-25
8-26
8-27
8-28
8-29
8-30
8-31
9-1
9-2
9-3
9-4
9-5
9-6
9-7
9-8
9-9
Rs
(Ly/day)
600
0
577
527
527
527
708
547
653
579
599
599
599
514
603
0
615
461
461
461
590
418
619
619
562
562
562
576
562
504
446
418
418
418
518
228
562
561
461
Wind
(km/day )
132
111
84
95
95
95
85
110
85
98
92
92
92
93
104
84
82
90
90
90
76
72
234
98
106
106
106
77
117
101
77
92
92
92
92
119
130
82
98
ft
18
16
14
15
15
15
17
17
14
16
19
19
19
16
18
18
17
14
14
14
13
16
14
11
13
13
13
14
13
14
12
13
13
13
16
15
11
11
15
Tw
14
14
12
12
12
12
13
13
12
13
16
16
16
15
15
14
14
13
13
13
12
13
11
9
11
11
11
12
11
11
10
11
11
11
14
13
9
9
12
ET east
(cm)
,61
.61
1.19
,40
.40
.40
.08
.81
,54
.76
.61
.61
.61
.64
.59
.59
.55
.25
.25
.25
.76
.32
1.19
.32
.74
.74
.74
1,54
.65
.49
.42
.42
.42
-.07
.23
1.28
1.28
.39
.39
ET west
(cm)
.60
.60
1,03
.14
.14
.14
,14
.59
.70
1.24
.75
.75
.75
1.24
.27
.65
.60
.57
.57
.57
.97
.32
1.19
.38
.88
.88
.88
1.16
1.08
.54
.40
.40
.40
.75
.34
1.31
.92
.58
.58
111
-------
Table B-l. Climatic data for 1972 (Continued).
Date
9-10
9-11
9-12
9-13
9-14
9-15
9-16
9-17
9-18
9-19
9-20
9-21
9-22
9-23
9-24
9-25
9-26
Rs
(Ly/Day)
461
461
490
576
547
547
532
532
532
461
216
518
504
418
418
418
418
Wind
(km/day)
98
98
167
105
80
84
109
109
103
116
105
82
71
84
84
84
84
Td
15
15
14
11
9
12
13
13
13
14
13
10
10
9
9
9
9
Tw
12
12
11
7
5
8
10
10
10
11
11
8
8
5
5
5
5
ET east
(cm)
.39
.92
.65
.38
.49
.58
.58
.58
.47
.59
.16
.16
.16
.16
.16
.16
.49
ET west
(cm)
.58
.70
.49
.59
.76
.85
.85
.85
.25
.59
.47
.47
.47
.47
.47
.47
.22
Table B-2. Lysimeter evapotranspiration (ET) and temperature (T) data
for 1973.
Date
6-16-73
6-17
6-18
6-19
6-20
6-21
6-22
6-23
6-24
6-25
6-26
ET east
(cm)
-
.74
_
.48
.64
.80
.79
.85
ET west
(cm)
.
_
.85
.26
.95
.90
.90
1.48
T wet
I
_
11
13
16
T dry
_
16
14
22
T max
26
£ \j
r* 1
21
21
32
~J £,
29
34
33
36
35
TQmin
1
E;
j
n
\j
A
H
7
7
7
12
13
12
112
-------
Table B-2. Lysimeter evapotranspiration (ET) and temperature (T) data
for 1973 (Continued).
Date
6-27
6-28
6-29
6-30
7-1
7-2
7-3
7-4
7-5
7-6
7-7
7-8
7-9
7-10
7-11
7-12
7-13
7-14
7-15
7-16
7-17
7-18
7-19
7-20
7-21
7-22
7-23
7-24
7-25
7-26
7-27
7-28
7-29
7-30
7-31
8-1
8-2
8-3
8-4
8-5
8-6
8-7
8-8
8-9
8-10
ET east
(cm)
.74
.80
1.22
.29
.29
1.64
.64
.53
.53
0
.65
.65
.65
.69
.48
.64
.54
.54
.02
.02
.05
.64
.85
.34
.58
.58
.58
.58
.69
.42
.58
.74
.64
.64
.05
.48
1.11
.37
.04
.04
.04
.64
.65
.65
0
ET west
(cm)
1.01
.85
.42
.93
.93
1.01
.74
.58
.62
.64
.74
.74
.74
1.06
.90
.85
.64
.37
.23
.23
.90
.53
.38
.34
.66
.66
.66
.66
.85
.69
.90
.85
.56
.56
.26
.58
.11
.11
.39
.39
.39
.58
.58
0
.64
T wet
(°0
16
14
15
-
12
13
16
15
18
12
-
-
14
13
13
17
17
15
-
12
13
11
17
16
-
-
-
15
14
12
16
15
-
16
12
15
13
12
-
-
14
16
-
12
13
T dry
(°0
17
18
18
-
32
16
17
18
25
14
-
-
17
16
17
19
18
17
-
12
15
12
18
16
-
-
-
17
17
14
18
17
-
19
13
21
17
15
-
-
16
18
14
14
T max
<°0
35
33
36
36
34
35
36
36
37
37
37
33
35
36
35
37
32
26
27
29
33
31
29
26
29
28
29
23
28
32
34
33
34
31
33
35
30
33
33
32
28
34
34
33
36
T min
<°0
14
15
10
13
14
10
14
12
12
11
13
11
12
12
13
16
16
13
13
10
9
11
14
10
9
10
4
10
12
10
10
11
11
11
12
11
12
10
12
12
11
9
9
7
10
113
-------
Table B-2. Lysimeter evapotranspiration (ET) and temperature (T) data
for 1973 (Continued).
Date
8-11
8-12
8-13
8-14
8-15
8-16
8-17
8-18
8-19
8-20
8-21
8-22
8-23
8-24
8-25
8-26
8-27
8-28
8-29
8-30
8-31
9-1
9-2
9-3
9-4
9-5
9-6
9-7
9-8
9-9
9-10
9-11
9-12
9-13
9-14
9-15
9-16
9-17
9-18
ET east
(cm)
.58
.58
.58
.58
.80
1.21
.66
.79
.42
1.23
.62
.47
.37
.58
.97
.97
.97
.74
.48
.64
.16
.16
.16
.16
.64
.64
.62
.32
,42
.42
.42
.42
.47
.42
.42
.39
.39
.39
.80
ET west
(cm)
.85
.85
.85
.69
1.06
1.32
.61
.74
.58
-.05
.72
.68
.58
1.06
1.08
1.08
1.08
.95
.79
.95
.08
.08
.08
.08
.69
.48
-.28
.80
.57
.57
.57
.57
.42
.48
.26
1.13
1.13
1.13
1.06
T wet
(°C)
_
-
12
11
13
12
16
23
13
19
16
17
16
18
-
-
16
11
12
13
-
-
8
11
9
9
9
-
-
14
12
11
11
-
-
7
T dry
(D0
_
-
17
14
17
15
17
19
14
22
17
29
16
22
-
-
17
13
13
16
-
-
-
9
15
11
11
11
-
-
16
13
11
36
-
-
10
T max
<°c>
36
34
34
37
34
36
33
32
34
31
32
28
34
32
32
32
-
-
-
-
29
19
16
21
24
28
29
30
23
25
24
18
21
27
29
28
28
26
28
T min
(°C)
10
10
10
12
9
10
12
12
12
13
13
12
14
13
7
9
10
6
4
7
7
7
2
3
4
4
8
7
10
5
11
11
4
4
10
7
7
2
4
114
-------
Table B-3. Dates of irrigation, amount applied, and EC of irriga-
tion water on Hullinger Farm in 1972.
Date
Block
5-23
6-28
7- 6
7-12
7-21
7-26
8- 3
8-15
8-22
8-29
9- 4
9-13
Block
5-23
7- 6
7-19
7-26
8- 3
8-11
8-15
8-22
Block
5-26
6-23
6-24
6-26
7-13
7-19
8- 7
8-11
8-23
8-28
9- 5
Amount EC
(cm) (mmho/c)
1 -
5.4
5.7
10.2
3.7
10.5
4.4
7.9
5.1
3.5
5.7
3.2
3.5
1 -
5.4
10.2
3.7
4.4
7.9
15.2
5.1
3.5
Corn
m
1.
1.
1.
1.
1.
1.
1.
1.
0.
0.
1.
Alfalfa
1.
0.
1.
1.
0.
1.
1.
_
0
0
0
0
6
6
2
3
9
9
3
-
0
8
6
6
9
2
3
2 - Alfalfa
1.0
5.1
5.1
5.1
10.2
1.8
14.3
8.3
14.3
7.9
16.2
0.
0.
1.
0.
0.
1.
0.
1.
0.
1.
9
9
1
8
8
6
8
0
9
2
Date
Block
5-23
6-23
6-25
6-26
7-10
7-14
7-18
8- 4
8- 7
8-11
8-15
8-18
8-21
8-24
8-28
8-31
9- 4
9- 7
9-12
Block
5-24
6-23
6-25
6-26
7-11
7-18
8- 8
8-10
8-15
8-24
8-30
9- 5
9-12
Amount EC Date
(cm) (mmho/c)
3 -
5.
5.
5.
5.
7.
2.
3.
15.
1.
3.
3.
1.
2.
2.
2.
1.
3.
0.
2.
4 -
5.
5.
5.
5.
5.
5.
9.
5.
4.
5.
5.
2.
3.
Alfalfa
1
1
1
1
0
4
5
2
6
3
2
4
2
2
9
3
2
6
9
0.9
1.1
1.1
1.0
1.0
0.9
1.4
1.6
0.9
1.2
1.0
1.3
0.9
0.8
0.9
0.9
1.3
1.1
Alfalfa
1
1
1
1
9
9
2
1
8
1
1
2
2
0.8
1.2
1.1
1.0
0.9
1.6.
1.2
1.2
0.8
0.9
1.2
1.2
Block
5-24
6-22
6-27
7-10
7-21
8- 7
8-17
8-28
9- 6
Block
5-25
6-24
6-28
7-11
7-19
8-10
8-11
8-16
8-24
8-31
9- 5
9-12
Block
5-25
6-22
6-28
7- 7
7-11
7-19
7-25
8- 2
8- 3
8- 9
8-16
8-22
8-29
9- 4
9-12
Amount EC
(cm) (mmho/c)
5 - Alfalfa
5.1
5.1
14.6
5.1
8.6
4.4
7.6
6.4
7.0
1
1
1
1
0
0
1
.1
.0
.0
.6
.9
.8
.0
6 - Alfalfa
5.7
10.2
1.9
5.6
7.5
9.1
5.6
4.1
5.7
4.8
1.9
3.2
0
1
1
0
1
0
1
0
1
1
1
.9
.1
.0
.8
.0
.9
.1
.8
.0
.3
.2
7 - Corn
2.9
2.5
6.0
8.6
3.8
8.9
7.8
7.0
2.2
5.4
7.3
4.8
7.0
3.8
5.1
-
-
1
1
1
0
1
1
1
1
1
1
0
0
1
.2
.0
.0
.8
.4
.5
.6
.3
.1
.2
.9
.9
.2
115
-------
Table B-3. Dates of irrigation, amount applied, and EC of irriga-
tion water on Hullinger Farm in 1972 (Continued).
Date
Block
5-25
6-22
6-28
7- 5
7-12
7-20
7-25
8- 3
8- 9
8-17
8-22
8-30
9- 5
9-13
Amount
(cm)
8 -
6.
2.
3.
10.
4.
7.
5.
7.
4.
5.
3.
5.
2.
4.
EC
(mmho/c)
Corn
4
9
8
2
8
1/9.
4/7.
0/9.
1/5.
1/7.
5/4.
4/7.
5/3.
1/5.
oa
5a
5*
4
oa
9*
2;
Ia
43
,
1
0
1
0
1
1
1
0
1
1
1
^^
.0
.9
.0
.9/0.
.4/1.
.5/1.
.3/1.
.9/0.
.1/1.
.0/0.
.0/1.
o
»:
5*
5*.
3*
9*
1*
9
1
Date
Block
5-23
6-24
6-28
7- 5
7-12
7-20
7-26
8- 3
8- 9
8-17
8-23
8-29
9- 5
9-13
Amount
(cm)
9 -
5.
3.
5.
10.
4.
7.
4.
7.
4.
5.
3.
4.
3.
3.
EC
(mmho/c)
Corn
4
2
7
2
1
9
9
6
1
9
0
8
5
8
0.
1.
1.
1.
1.
1.
1.
1.
0.
1.
1.
1.
9
0
0
0
0
6
5
3
9
2
0
0
First figure is for plots SAM and 5AS. Second figure is for plot
SAN.
116
-------
Table B-4. Dates of irrigation, amount applied and EC of irri-
gation water on Hullinger Farm in 1973.
Date
Block
6-21
6-25
7- 1
7-10
7-20
8- 1
8- 9
8-21
Block
5-28
6-14
7- 1
7-10
8- 9
8-21
Block
5-24
6-15
7- 1
7-10
8- 6
8-18
9- 3
Block
5-25
6-16
7- 2
7- 3
7-11
8- 6
8-18
9- 4
Amount
(cm)
1 - Corn
1.3
1.3
5.1
6.7
5.7
5.1
5.1
EC Date Amount EC Date
(mmho/c) (cm) (mmho/c)
0.7
0.8
1.0
1.2
1.2
4.9 1.0
1 - Alfalfa
5.1
7.6
5.1
6.7
5.1
0.7
1.2
4.9 1.0
2 - Alfalfa
7.6
12.1
6.4
6.7
8.9
7.0
7.7
0.8
0.7
1.3
1.0
1.5
3 - Alfalfa*
7.6
7.6
2.2
5.4
6.7
8.9
7.0
7.4
.__
0.6
0.6
0.7
1.3
1.0
1.3
Block 4
5-25
6-17
7- 4
7-11
8- 7
8-19
9- 4
Block 5
5-26
6-17
7- 5
7-12
8- 8
8-19
9- 5
Block 6
5-26
6-15
7- 5
7-12
8- 8
8-20
9- 5
Block 7
7- 2
7-13
7-20
7-31
8- 9
8-20
- Alfalfaa
7.6
7.6
7.6
7.3
8.9
7.2
7.9
___
0.6
0.7
1.2
0.9
1.5
- Alfalfa3
7.6
7.6
7.6
6.7
8.9
7.1
._T
1.5
0.7
0.7
1.2
0.9
7.7 1.4
- Alfalfa
7.6
7.6
7.6
6.7
8.9
7.0
7.6
- Corn
5.1
6.7
3.8
5.1
5.1
5.1
0.7
0.7
1.2
0.9
1.5
0.7
0.8
0.9
0.9
1.2
0.9
Block
7- 2
7-13
7-20
7-31
8- 9
8-21
Block
7- 3
7-14
7-20
8- 1
8- 9
8-21
Block
6-21
6-25
7- 3
7-14
7-20
8- 1
8- 9
8-21
Amount EC
(cm) (mmho/c)
8 - Corn
5.1
6.7
3.8
5.1
5.1
5.3
9 - Corn
5.1
6.7
5.7
5.1
5.1
4.9
9 - Corn
1.3
1.3
5.1
6.7
5.7
5.1
5.1
4.9
0.6
0.8
0.9
0.9
1.2
0.9
East
0.7
0.8
1.0
1.2
1.2
1.0
West
0.7
0.8
1.0
1.2
1.2
1.0
aAs part of an independent study of drain performance (Sabti; 1974),
plots over drains IN, 2N, and 3N received two additional irrigations
of 15.2 cm each on 6-19 and 6-25.
available.
EC for these two irrigations not
117
-------
Table B-5. Discharge of tile drains on Hullinger farm in 1972. A blank in the data
indicates no flow.
00
(ra3/hr)
Date
6-28
6-29
6-30
7-3
7-5
7-7
7-10
7-11
7-12
7-13
7-14
7-17
7-18
7-19
7-20
7-21
7-22
7-25
7-26
7-27
7-28
7-31
8-1
8-3
8-4
8-7
8-8
8-9
8-10
3N
1.02
0.31
0.20
0.10
0.20
0.20
0.10
0.97
0.80
0.34
0.19
4N
1.02
0.61
0.20
2.04
1.02
2.04
0.99
0.80
0.72
0.45
0.31
2.24
1.01
0.62
0.29
0.85
0.93
0.45
0.20
0.76
1.43
1.33
1.53
1.12
0.83
0.61
4M 4S
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
06
10
03
a
a
31
15
06
05
03
02
62
42
24
03
44
38
20
02
08
75
73
54
44
53
39
5N
1.02
1.02
0.10
0.06
1.02
5.10
3.06
5.10
3.26
0.88
1.53
0.91
4.08
1.83
0.19
1.43
1.01
3.06
2.24
1.12
0.70
1.22
3.77
2.55
1.83
0.99
2.45
0.90
Drain b
5M 5S
0.20
0.20
0.01
a
0.92
0.71
1.02
0.95
0.05
1.94
0.46
0.66
0.27
1.43 1.01
0.68 0.47
0.23 0.09
1.94 1.12
1.01 1.12
0.27 0.10
0.09
1.12 1.63
0.39 0.31
SAN
0.04
0.07
0.03
0.20
0.71
0.51
0.92
0.42
0.36
0.23
0.10
0.10
0.15
0.43
0.23
0.13
0.60
0.41
0.18
0.09
0.10
0.91
0.45
0.20
0.09
0.06
0.20
SAM
*
0.02
0.01
0.20
0.20
0.20
0.41
0.26
0.20
0.10
0.08
0.06
0.10
0.40
0.20
0.07
0.58
0.29
0.20
0.04
0.04
0.84
0.33
0.10
0.08
0.09
0.20
5AS
0.33
0.51
0.52
0.32
0.66
0.73
0.20
0.07
0.10
0.27
6N
0.03
0.04
0.01
0.61
3.06
2.04
2.04
1.73
0.99
0.56
0.01
0.29
2.55
1.01
0.45
0.95
1.33
0.51
0.17
0.33
0.91
1.83
0.10
0.18
0.01
0.32
6M 6S
0.20
0.41
0.31
0.61
0.42
0.06
0.05
0.30
0.03
2.55
0.58
0.03
0.35
0.88 0.71
0.20
0.39
1.22 0.36
0.03
0.06
0.21
-------
Table B-5. Discharge of tile drains on Hullinger farm in 1972,
indicates no flow (Continued).
A blank in the data
vo
Date
8-11
8-15
8-16
8-17
8-18
8-21
8-22
8-24
8-25
8-28
8-30
8-31
9-1
9-2
9-3
9-4
9-5
9-7
9-8
9-11
9-12
9-13
9-14
9-15
9-16
9-22
3N 4N
0.75 3.57
0.05
0.83
0.90
0.29 1.02
0.09 1.12
0.02 0.87
0.42
1.43
0.09
0.52
1.73
2.04
1.43
0.82
0.43
0.69
0.47 0.57
0.21 1.02
0.08
0.44
0.38
a 0.74
1.02
0.10
4M 4S
2.34 0.58
0.20
0.67 0.47
0.10 0.01
0.99
0.45
0.43
0.36
1.12
0.15
0.60
1.33
1.22
0.97
0.68
0.39
0.56
0.54
0.20
0.06
0.03
0.40
0.24
0.18
0.31
0.03
5N
1.33
1.73
1.73
1.83
1.22
1.33
1.22
0.16
2.45
1.94
2.34
1.22
0.72
0.25
1.33
0.41
0.97
0.06
0.91
0.82
0.87
1.02
0.01
Drain
5M 5S
0.48 0.31
0.76 0.39
0.41 0.31
0.10
0.07
0.25
0.19
1.12
0.55
0.43
0.22
0.03
0.41 a
0.09
0.04
5AN
0.09
0.01
0.01
0.14
0.27
0.25
0.20
0.10
0.12
a
0.22
0.23
0.12
0.05
a
0.15
0.02
0.03
0.05
0.06
SAM 5AS
0.10 0.10
0.01
0.06
0.06
0.10
0.09
0.07
0.20
0.07
a
0.07
0.15
0.11
0.07
0.04
a
0.14
0.02
0.07
0.02
0.02
6N
0.01
0.02
1.22
1.22
0.75
0.76
0.31
0.05
0.55
0.64
0.19
a
0.14
6M 6S
0.03
0.33
0.10
0.07
0.10
0.04
a
0.11
0.06
a
0.06
Indicates measurable flow less than 0.01 m3/hr. A blank indicates no flow from the drain on that date.
Drains not listed had no flow in 1972.
-------
Table B-6. Discharge of tile drains on Hullinger farm in 1973.
(m3/hr)
Date
6-18
6-19
6-20
6-21
6-22
6-25
6-26
6-27
6-28
6-29
7'2
8 7-3
7-4
7-5
7-9
7-12
7-13
7-16
7-17
7-18
7-19
7-20
7-24
7-25
7-26
7-27
7-30
7-31
8-1
8-2
IN 1M
1.22 0.31
0.31
0.10
1.22
0.10
1.02
1.22
1.02
1.02
0.82
0.20
2N 2M
2.24 0.82
0.61 0.20
0.10
0.61
3.06
0.51
0.51
1.02
1.22
0.82
1.03
1.53
1.53
0.82
0.10
0.31
3N 3M
3.87 1.02
1.22 0.20
0.61 0.10
2.24
4.59
1.53
0.82
0.51
2.65
1.83
2.65
2.65
1.83
2.24
2.65
2.65
2.24
1.53
0.82
0.20
0.31-
1.02
1.22
b
Drain
4N
1.63
1.73
2.85
1.63
1.73
0.51
1.43
1.22
0.71
0.41
0.51
0.10
0.10
0.92
3.06
2.65
2.55
1.73
2.24
2.55
2.14
1.94
1.43
1.02
0.41
0.61
1.33
1.43
4M
1.02
1.12
1.63
1.12
1.02
0.41
0.61
0.61
0.41
0.20
0.10
a
a
0.20
a
1.83
1.12
1.02
0.82
0.82
1.12
0.82
0.71
0.61
0.51
0.31
0.31
0.51
0.51
5N
1.53
1.22
1.02
1.12
2.55
1.02
1.43
1.22
0.82
0.71
1.02
0.82
0.61
1.12
0.20
0.10
2.24
2.85
2.65
1.73
2.24
4.08
2.34
2.14
1.83
1.43
0.51
1.02
1.73
1.63
5M
0.20
0.10
0.20
0.10
0.20
0.71
0.10
0.10
0.41
0.31
0.20
0.20
0.82
0.31
0.20
0.31
0.10
0.10
0.10
SAN
0.20
0.10
0.10
0.10
0.31
0.20
0.20
0.20
0.10
0.10
0.20
0.10
0.10
0.20
a
0.10
0.41
0.41
0.31
0.31
0.31
0.31
0.31
0.41
0.20
0.10
0.31
0.20
0.20
SAM
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
a
0.10
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.10
a
0.10
0.10
0.10
6N
0.71
0.51
0.41
0.61
1.33
0.92
1.53
0.92
0.51
0.31
0.71
0.31
0.51
1.22
0.10
0.10
0.71
1.94
1.83
1.12
1.33
1.73
1.53
1.33
3.57
1.33
0.51
0.82
1.02
1.33
6M
0.10
0.10
0.10
0.10
0.10
0.10
0.31
0.20
0.10
0.10
0.10
a
0.20
0.31
0.10
0.51
0.41
0.31
0.31
0.51
0.41
0.31
0.92
0.31
a
0.10
0.20
0.31
-------
Table B-6, Discharge of tile drains on Hullinger farm in 1973 (Continued).
N>
(m3/hr)
Date IN 1M 2N
8-6
8-7
8-8 0.10
8-9
8-10
8-13
8-14
8-15
8-16
8-17
8-20
8-21
8-22 0.51
8-23 0.20
8-27 0.10
8-28
8-29
9-3
9-4
9-5 0.51
9-6
9-7 0.82
9-12
9-13
9-14
0.31
0.20
0.61
1.02
0.82
0.82
0.51
1.53
1.53
1.83
1.83
1.22
0.82
2M 3N 3M
0.
0.
2.
2.
1.
1.
1.
1.
2.
1.
4.
3.
2.
2.
1.
1.
1.
1.
1.
a 2.
a 4.
3.
3.
3.
2.
31
20
65
24 0.51
02
22
53
83
24
83
59 0.41
06 0.31
65 0.10
65
83
53
22
53
53
65
59 0.31
98 0.41
47
06
65
Drain b
4N 4M
0.61
0.61
0.82
4.18
1.94
2.85
3.57
3.57
3.77
3.26
7.65
3.87
3.47
2.65
2.96
2.14
1.83
2.24
1.83
1.73
5.10
3.87
3.26
3.06
2.96
0.20
0.20
0.20
3.26
1.63
0.82
0.82
0.92
0.92
0.92
3.36
2.45
1.83
1.43
0.82
0.61
0.51
0.41
0.31
0.41
3.06
2.04
1.22
1.12
1.02
5N
0.61
0.51
0.41
3.47
1.73
5.00
5.40
5.71
5.81
4.59
4.18
4.69
3.98
3.26
3.36
2.65
2.34
2.24
2.04
1.73
3.16
2.96
2.65
2.65
2.55
5M
1.22
0.51
0.41
0.51
0.41
0.41
0.31
0.41
1.33
0.82
0.61
0.41
0.20
0.10
0.41
0.31
0.20
0.20
0.10
5AN
0.10
0.10
0.10
0.20
0.31
0.71
0.82
0.92
0.82
0.71
0.51
0.82
0.61
0.51
0.51
0.41
0.41
0.31
0.20
0.20
0.31
0.20
0.31
0.31
0.31
SAM
a
a
0.10
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.41
0.31
0.20
0.20
0.20
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
6N
0.20
0.10
0.41
0.41
1.02
3.98
4.49
4.49
4.69
3.57
4.08
4.89
3.67
3.16
3.57
2.85
2.34
1.73
1.33
1.22
1.22
1.33
1.02
1.02
0.92
6M
0.51
0.41
0.41
0.41
0.41
0.31
0.61
1.73
1.12
1.02
1.02
0.61
0.51
0.20
0.20
0.10
0.20
0.20
0.10
0.10
0.10
Indicates measurable flow less than 0.01 m^/hr. A blank indicates no flow from the drain on
that date.
Drains not listed had no flow in 1973.
-------
Table B-7. Water table depth and elevation at selected piezometers
on Hullinger farm in 1972.
Date
4-21
5-5
6-7
7-4
7-11
7-18
7-19
7-27
8-4
8-10
8-18
8-25
8-26
8-28
9-2
9-11
9-22
9-29
10-9
4-21
5-5
6-7
7-4
7-11
7-18
7-27
8-4
8-10
8-18
8-25
8-28
9-2
9-11
9-16
9-22
9-29
10-9
Depth
(m)
]
2.05
2.10
0.80
1.70
1.22
1.26
1.31
1.19
1.20
1.47
1.34
1.53
0.98
1.40
1.10
1.41
0.94
1.93
1.99
1.13
1.52
1.12
1.26
1.22
1.16
1.19
1.25
1.30
1.40
1.05
1.27
1.25
1.29
1.11
Elev. a
Lb
0.94
0.89
2.19
1.29
1.77
1.73
1.68
1.80
1.79
1.52
1.65
1.46
2.01
1.59
1.89
1.58
2.05
5
2.34
2.28
3.14
2.75
3.15
3.01
3.05
3.11
3.08
3.02
2.97
2.87
3.22
3.00
3.02
2.98
3.16
Depth
1.95
1.99
0.87
1.60
1.19
1.33
1.27
1.36
1.26
1.43
0.94
1.32
1.09
1.34
1.00
2.06
2.11
1.64
1.29
1.40
1.37
1.30
1.33
1.36
1.41
1.39
1.44
1.29
Elev. a
On)
2
0.95
0.91
2.03
1.30
1.71
1.57
1.63
1.54
1.64
1.47
1.96
1.58
1.81
1.56
1.90
6
2.31
2.26
2.73
3.08
2.97
3.00
3.07
3.04
3.01
2.96
2.98
2.93
3.08
Depth
(m)
2.16
2.21
1.16
1.82
1.44
1.57
1.52
1.58
1.34
1.65
1.24
1.55
1.34
1.58
1.28
1.70
1.76
0.84
1.29
0.82
1.01
0.96
0.88
0.99
1.05
1.05
1.17
0.88
1.04
1.02
1.02
0.86
Elev. a
On)
3
0.94
0.89
1.94
1.28
1.66
1.53
1.58
1.52
1.76
1.45
1.86
1.55
1.76
1.52
1.82
7
2.74
2.68
3.60
3.15
3.62
3.43
3.48
3.56
3.45
3.39
3.39
3.27
3.56
3.40
3.42
3.42
3.58
Depth
On)
1.95
2.01
1.09
1.54
1.09
1.25
1.21
1.13
1.21
1.30
1.33
1.43
1.03
1.28
1.24
1.26
1.04
2.03
2.09
1.30
1.60
1.36
1.33
1.24
1.30
1.32
1.32
1.18
1.35
1.14
1.41
1.27
Elev. a
On)
4
2.34
2.28
3.20
2.75
3,20
3.04
3.08
3.16
3.08
2.99
2.96
2.86
3.26
3.01
3.05
3.03
3.25
8
2.68
2.62
3.41
3.11
3.35
3.38
3.47
3.41
3.39
3.39
3.53
3.36
3.57
3.30
3.44
122
-------
Table B-7. Water table depth and elevation at selected piezometers
on Hullinger farm in 1972 (Continued).
Date
4-21
5-5
6-7
7-4
7-11
7-18
7-27
7-28
8-4
8-10
8-18
8-25
8-28
9-2
9-11
9-16
9-22
9-29
10-9
4-21
5-5
6-7
7-4
7-11
7-18
7-27
8-4
8-10
8-18
8-25
8-28
9-2
9-11
9-16
9-22
9-29
10-9
Depth
(m)
9
2.02
2.07
1.08
1.52
0.90
1.22
1.19
1.12
1.30
1.07
1.21
1.38
1.29
1.41
1.45
1.46
1.42
13
2.06
2.11
0.84
1.47
0.84
1.16
1.16
1.09
1.31
1.05
1.15
1.33
1.27
1.40
1.46
1.46
1.44
Elev. a
(m)
4.64
4.59
5.58
5.14
5.76
5.44
5.47
5.54
5.36
5.59
5.45
5.28
5.37
5.25
5.21
5.20
5.24
5.33
5.28
6.55
5.92
6.55
6.23
6.23
6.30
6.08
6.34
6.24
6.06
6.12
5.99
5.93
5.93
5.95
Depth
(m)
2.05
2.09
1.01
1.53
0.96
1.24
1.17
1.02
1.26
1.05
1.16
1.38
1.29
1.39
1.43
1.43
1.39
2.41
2.47
1.40
1.80
1.30
1.52
1.50
1.44
1.62
1.44
1.55
1.58
1.73
1.63
1.82
1.80
Elev. a
(m)
10
4.57
4.53
5.61
5.09
5.66
5.38
5.45
5.60
5.36
5.57
5.46
5.24
5.33
5.23
5.19
5.19
5.23
14
4.98
4.92
5.99
5.59
6.09
5.87
5.89
5.95
5.77
5.95
5.84
5.81
5.66
5.76
5.57
5.59
Depth
(m)
2.37
2.41
1.42
1.51
1.32
1.49
1.37
1.52
1.48
1.63
1.50
1.72
1.69
2.21
2.43
1.57
1.80
1.55
1.62
1.51
1.48
1.45
1.59
1.61
1.68
1.58
Elev. a
(m)
11
4.59
4.55
5.54
5.45
5.64
5.47
5.59
5.44
5.48
5.33
5.46
5.24
5.27
15
2.22
2.00
2.86
2.63
2.88
2.81
2.92
2.95
2.98
2.84
2.82
2.75
2.85
Depth
(m)
2.15
2.20
1.11
1.57
0.89
1.25
1.29
1.26
1.45
1.09
1.26
1.42
1.38
1.52
1.58
1.59
1.56
1.20
1.13
1.17
1.15
1.07
1.09
1.24
1.16
1.29
1.25
Elev.a
(m)
12
5.33
5.28
6.37
5.91
6.59
6.23
6.19
6.22
6.03
6.39
6.22
6.06
6.10
5.96
5.90
5.89
5.92
16
3.88
3.95
3.91
3.93
4.01
3.99
3.84
3.92
3.79
3.83
123
-------
Table B-7. Water table depth and elevation at selected piezometers
on Hullinger farm in 1972 (Continued).
Date
4-21
5-5
5-26
6-7
7-5
7-11
7-18
7-27
7-28
8-4
8-10
8-18
8-25
9-2
9-11
9-16
9-29
10-9
4-21
5-5
6-7
7-4
7-11
7-18
7-28
8-4
8-10
8-18
8-25
8-28
9-2
9-11
9-16
9-22
9-29
10-9
Depth
(m)
17
1.01
0.97
1.03
1.03
1.05
1.01
1.13
1.07
1.23
1.23
21
2.00
2.07
1.45
1.52
1.35
1.34
1.26
1.16
1.23
1.23
1.26
1.25
1.38
1.32
1.53
1.50
Kiev. a
(m)
4.89
4.93
4.87
4.87
4.85
4.89
4.77
4.83
4.67
4.67
4.01
3.94
4.56
4.49
4.66
4.67
4.75
4.85
4.78
4.78
4.75
4.76
4.63
4.69
4.48
4.51
Depth
(m)
18
1.16
1.11
1.20
1.22
1.30
1.28
1.46
1.35
1.53
1.53
22
1.18
1.03
1.16
1.50
1.26
1.26
1.41
1.33
1.55
1.51
Elev. a
(m)
5.74
5.79
5.70
5.68
5.60
5.62
5.44
5.55
5.37
5.37
5.66
5.81
5.68
5.34
5.58
5.58
5.43
5.51
5.29
5.33
Depth
(m)
19
2.40
2.45
1.55
1.39
1.53
1.48
1.42
1.52
1.50
1.55
1.57
1.72
1.63
1.84
1.81
23
2.27
2.33
1.58
1.33
1.43
1.35
1.20
1.34
1.34
1.44
1.46
1.62
1.53
1.76
1.71
Elev. a
(m)
5.28
5.23
6.13
6.29
6.15
6.20
5.26
6.16
6.18
6.13
6.11
5.96
6.05
5.84
5.87
5.20
5.14
5.89
6.14
6.04
6.12
6.27
6.13
6.13
6.03
6.01
5.85
5.94
5.71
5.76
Depth
(m)
20
1.92
1.99
1.67
1.46
1.52
1.40
1.35
1.26
1.30
1.25
1.23
1.25
1.06
1.32
1.49
1.46
24
1.91
1.80
1.85
1.67
1.86
1.72
1.89
1.97
2.04
2.02
Elev. a
(m)
3.23
3.16
3.48
3.69
3.63
3.75
3.80
3.89
3.85
3.90
3.92
3.90
4.09
3.83
3.66
3.69
3.39
3.50
3.45
3.63
3.44
3.58
3.41
3.33
3.26
3.28
124
-------
Table B-7. Water table and elevation at selected piezometers
on Hullinger farm in 1972 (Continued).
Date
4-21
5-5
6-7
7-5
7-11
7-18
7-28
8-4
8-10
8-18
8-25
8-28
9-2
9-11
9-16
9-22
9-29
10-9
Depth
(m)
25
1.69
1.61
1.67
1.67
1.78
1.70
1.81
1.88
1.98
1.98
Elev. a
(m)
4.62
4.70
4.64
4.64
4.53
4.61
4.50
4.43
4.33
4.33
Depth
On)
26
1.65
1.58
1.66
1.74
1.83
1.76
1.89
1.93
2.01
1.99
Elev.a
(m)
5.38
5.45
5.37
5.29
5.20
5.27
5.14
5.10
5.02
5.04
Depth
(m)
27
2.78
2.83
2.24
2.25
2.10
2.14
1.99
1.91
1.99
2.10
2.18
2.13
2.24
2.27
2.35
2.31
Elev. a
(m)
5.13
5.08
5.67
5.66
5.81
5.77
5.92
6.00
5.92
5.81
5.73
5.78
5.67
5.64
5.56
5.60
Depth
(m)
2.51
2.56
1.69
1.80
1.49
1.61
1.55
1.42
1.60
1.55
1.60
1.67
1.80
1.70
1.96
1.85
Elev. 3
(m)
28
5.80
5.75
6.62
6.51
6.82
6.70
6.76
6.89
6.71
6.76
6.71
6.64
6.51
6.61
6.35
6.46
^Elevation above mean sea level is value given plus 1600 m.
b
Piezometer identification number, see Table 6.
125
-------
Table B-8. Water table depth and elevation at selected piezometers
on Hullinger farm in 1973.
Date
Depth
(m)
Elev. a
(m)
Depth Elev. a
(m) (m)
lb
6-18
6-25
7-2
7-9
7-16
7-25
7-30
8-6
8-13
8-20
8-27
9-3
9-14
6-18
6-25
7-2
7-9
7-16
7-25
7-30
8-6
8-13
8-20
8-27
9-3
9-14
6-18
6-25
7-2
7-9
7-16
7-25
7-30
0.88
1.19
0.71
1.32
0.24
0.44
1.20
1.04
0.97
0.57
0.67
0.72
0.64
0.85
1.19
1.08
1.28
0.74
0.84
1.17
1.13
1.00
0.82
0.83
0.86
0.87
1.18
1.22
1.17
1.36
1.06
1.13
1.28
2.11
1.80
2.27
1.66
2.75
2.54
1.78
1.95
2.01
2.42
2.31
2.26
2.35
5
3.42
3.08
3.19
2.99
3.53
3.43
3.10
3.14
3.27
3.45
3.44
3.41
3.40
9
5.49
5.44
5.49
5.30
5.60
5.53
5.38
0.81
1.11
0.79
1.24
0.37
0.51
1.13
1.00
0.96
0.59
0.68
0.77
0.66
1.21
1.37
1.30
1.43
1.10
1.16
1.36
1.33
1.24
1.13
1.16
1.19
1.18
1.19
1.21
1.14
1.37
0.98
1.08
1.26
2
2.08
1.79
2.11
1.66
2.52
2.39
1.76
1.89
1.94
2.31
2.22
2.12
2.24
6
3.16
3.00
3.07
2.94
3.26
3.20
3.01
3.04
3.12
3.24
3.20
3.17
3.19
10
5.43
5.41
5.48
5.25
5.63
5.54
5.36
Depth Elev. a
(m) (m)
1.04
1.33
1.08
1.46
0.71
0.79
1.36
1.23
1.19
0.85
0.94
1.06
0.92
0.80
0.98
0.83
1.09
0.38
0.60
0.93
0.91
0.65
0.49
0.50
0.53
0.52
1.45
1.48
1.44
1.63
1.32
1.36
1.55
3
2.06
1.77
2.02
1.64
2.39
2.31
1.74
1.86
1.90
2.25
2.16
2.04
2.18
7
3.64
3.46
3.61
3.35
4.06
3.84
3.51
3.53
3.79
3.95
3.94
3.91
3.92
11
5.51
5.48
5.52
5.33
5.64
5.60
5.41
Depth Elev. a
(m) (m)
0.98
1.19
1.02
1.30
0.59
0.71
1.15
1.10
0.95
0.75
0.72
0.73
0.76
1.11
1.30
1.20
1.39
0.89
1.02
1.28
1.25
1.06
0.92
0.96
1.00
0.98
1.23
1.22
1.18
1.40
1.10
1.19
1.33
4
3.31
3.10
3.27
2.99
3.71
3.59
3.14
3.19
3.35
3.54
3.58
3.57
3.54
8
3.60
3.42
3.51
3.33
3.82
3.69
3.43
3.46
3.65
3.80
3.76
3.71
3.73
12
6.24
6.25
6.30
6.08
6.37
6.29
6.15
126
-------
Table B-8.
Water table depth and elevation at selected piezometers
on Hullinger farm in 1973 (Continued) .
Date
8-6
8-13
8-20
8-27
9-3
9-14
6-18
6-25
7-2
7-9
7-16
7-25
7-30
8-6
8-13
8-20
8-27
9-3
9-14
6-18
6-25
7-2
7-9
7-16
7-25
7-30
8-6
8-13
8-20
8-27
9-3
9-14
Depth
(m)
1.29
0.47
0.85
0.88
1.04
1.11
13
1.11
1.10
1.05
1.28
0.96
1.06
1.21
1.24
0.44
0.75
0.77
0.98
1.09
17
1.03
1.06
1.08
1.11
1.04
1.00
1.07
1.07
0.99
0.93
0.95
1.01
0.99
Elev. a
On)
5.37
6.19
5.81
5.78
5.62
5.55
6.28
6.29
6.34
6.11
6.43
6.33
6.18
6.15
6.95
6.64
6.62
6.41
6.30
4.87
4.84
4.82
4.79
4.86
4.90
4.83
4.83
4.91
4.97
4.95
4.88
4.91
Depth
(m)
1.29
0.66
0.88
0.89
1.06
1.09
14
1.52
1.46
1.41
1.59
1.32
1.40
1.53
1.56
1.05
1.19
1.20
1.35
1.43
18
1.26
1.29
1.28
1.39
1.16
1.22
1.35
1.35
1.03
1.11
1.09
1.22
1.24
Elev. a
(m)
5.33
5.96
5.74
5.73
5.56
5.52
6.15
6.21
6.26
6.08
6.34
6.27
6.14
6.10
6.62
6.48
6.47
6.32
6.24
5.64
5.61
5.62
5.51
5.74
5.68
5.55
5.55
5.87
5.79
5.81
5.68
5.66
Depth
(m)
1.56
0.99
1.17
1.20
1.34
1.37
15
1.37
1.49
1.48
1.56
1.33
1.51
1.50
1.43
1.34
1.38
1.42
1.37
19
1.50
1.51
1.51
1.61
1.42
1.45 .
1.56
1.58
1.37
1.37
1.36
1.48
1.52
Elev. 3
(m)
5.40
5.96
5.79
5.76
5.62
5.59
3.05
2.94
2.95
2.87
3.10
2.92
2.93
3.00
3.09
3.05
3.00
3.06
6.18
6.16
6.17
6.07
6.26
6.23
6.12
6.10
6.31
6.31
6.32
6.20
6.16
Depth
(m)
1.35
0.51
0.82
0.86
1.09
1.20
16
1.13
1.19
1.20
1.24
1.08
1.19
1.19
1.09
0.99
1.08
1.12
1.09
20
1.27
1.32
1.36
1.36
1.27
1.33
1.35
1.28
1.16
1.28
1.33
1.30
Elev. a
(m)
6.12
6.97
6.65
6.62
6.39
6.28
3.95
3.89
3.88
3.84
4.00
3.89
3.89
3.99
4.09
3.99
3.96
3.98
3.88
3.83
3.79
3.79
3.88
3.82
3.81
3.88
3.99
3.87
3.82
3.85
127
-------
Table B-8. Water table depth and elevation at selected piezometers
on Hullinger farm in 1973 (Continued).
Date
6-18
6-25
7-2
7-9
7-16
7-25
7-30
8-6
8-13
8-20
8-27
9-3
9-14
6-18
6-25
7-2
7-9
7-16
7-25
7-30
8-6
8-13
8-20
8-27
9-3
9-14
Depth
(m)
21
1.27
1.32
1.35
1.38
1.24
1.27
1.34
1.35
1.24
1.26
1.23
1.32
1.30
25
1.73
1.76
1.80
1.83
1.73
1.71
1.77
1.80
1.73
1.78
1.73
1.80
1.80
Elev.a
On)
4.74
4.69
4.66
4.63
4.76
4.74
4.67
4.66
4.77
4.75
4.77
4.68
4.71
4.58
4.55
4.51
4.48
4.58
4.60
4.54
4.51
4.58
4.53
4.58
4.51
4.51
Depth
(m)
22
1.22
1.27
1.29
1.35
1.17
1.19
1.31
1.33
1.18
1.19
1.13
1.26
1.28
26
1.75
1.80
1.83
1.85
1.73
1.69
1.79
1.83
1.76
1.80
1.71
1.81
1.83
Elev. a
(m)
5.62
5.57
5.56
5.49
5.67
5.65
5.53
5.52
5.67
5.65
5.71
5.58
5.56
5.29
5.24
5.20
5.18
5.30
5.35
5.25
5.21
5.27
5.24
5.32
5.22
5.20
Depth
(m)
23
1.36
1.41
1.43
1.49
1.30
1.34
1.46
1.48
1.34
1.32
1.24
1.40
1.44
27
2.05
1.82
2.15
2.17
2.01
1.98
2.09
2.14
2.10
2.12
1.97
2.12
2.18
Elev.3
(m)
6.11
6.06
6.05
5.98
6.18
6.13
6.01
6.00
6.14
6.15
6.24
6.07
6.03
5.86
6.09
5.75
5.74
5.89
5.92
5.81
5.76
5.80
5.79
5.93
5.79
5.72
Depth
24
1.76
1.85
1.84
1.93
1.78
1.87
1.89
1.79
1.70
1.81
1.91
1.85
28
1.43
1.52
1.52
1.62
1.35
1.42
1.56
1.59
1.47
1.36
1.19
1.47
1.63
Elev. a
3.54
3.45
3.46
3.37
3.52
3.43
3.41
3.51
3.60
3.49
3.39
3.45
6.88
6.78
6.79
6.69
6.96
6.89
6.75
6.72
6.84
6.95
7.12
6.84
6.68
aElevation above mean sea level is value given plus 1600 m.
Piezometer identification number, see Table 6.
128
-------
Table B-9. EC of tile drain effluent on Hullinger farm in 1972.
(mmho/cm)
VO
Date
6-28
6-29
6-30
7-3
7-5
7-7
7-10
7-11
7-12
7-13
7-14
7-17
7-18
7-19
7-20
7-21
7-22
7-25
7-26
7-27
7-28
7-31
8-1
8-3
8-4
8-7
8-8
8-9
3N
2.0
2.0
1.9
1.8
1.8
1.7
1.6
1.8
2.1
2.0
4N
1.4
1.4
1.4
1.3
1.3
1.2
1.6
1.2
1.2
1.3
1.4
1.3
1.9
1.4
1.4
1.5
1.2
1.1
1.3
1.4
1.3
1.3
1.3
1.4
1.4
4M
2.2
2.1
2.0
2.3
2.1
2.2
2.3
2.1
2.0
2.2
2.1
2.1
2.0
2.1
2.2
1.8
1.8
1.9
1.8
2.0
1.8
1.6
1,9
2.1
2.0
4S 5N
1.5
1.6
1.5
1.7
1.2
1.4
1.4
1.3
1.7
1.4
1.4
1.5
1.7
1.7
1.6
1.5
1.6
1.7
1.6
1.5
1.4
1.5
1.7
1.5
1.7
1.9
1,9
5M
1.7
1.6
1.7
1.2
1.6
1.5
1.6
1.6
1.5
1.7
1.8
1.7
1.6
1,9
1,8
1.6
1.8
1.8
1,9
2,1
2.0
Drain
5S
1.9
1.9
1.7
1.8
1.9
2.0
2.3
SAN
1.8
2.0
2.0
1.8
1.8
1.6
1.7
2.1
1.6
1.3
1.7
1.8
1.8
2,0
1.8
2.9
2.9
2.0
1,8
2.1
2.0
2.7
1,9
2.1
2,4
2.4
5AM 5AS
2.
2.
2.
1.
2.
2.
2.
1.
2.
2.
2,
2.
2.
2.
1.
2,
2.
1.
2.
1.
2.
2.
2.
2,
2.
2.
2
3
1
8
2
1
2
9
1
0
1
0
0
2 2.3
9
1
1 2.4
9 2,1
1 2.0
8
1
8 2.2
1 1.9
0 2.0
4 2,3
1 2,2
6N
1.6
1.5
1.7
1.2
1.3
1.2
1.3
1.3
1.4
1,4
1.5
1.5
1.5
1.5
1.6
1.7
1.6
1.5
1,7
1,5
1.6
1.7
2.1
1,9
2,0
6M 6S
1.5
1.7
1.6
1.6
1.9
1.8
1,8
2.0
1.9
2.5
1.9
2.0
1.9
2.2 3.0
1.9
1.8
1.9 2.8
2.0
2,0
-------
Table B-9. EC of tile drain effluent on Hullinger farm in 1972 (Continued).
(mmho/cm)
Date
8-10
8-11
8-15
8-16
8-17
8-18
8-21
8-22
8-24
8-25
8-28
C 8-30
0 8-31
9-1
9-2
9-3
9-4
9-5
9-7
9-8
9-11
9-12
9-13
9-14
9-15
9-16
9-22
3N 4N
1.9 1.4
2.2 1.6
1.6
1.7
1.7
2.5 1.7
2.2 1.6
2.2 1.7
1.6
1.7
1.7
1.7
1.7
1.7
1.2
1.6
1.6
1.7
2.4 1.7
2.6 1.8
1,8
1.9
1.9
2.3 1.8
1.8
1.7
4M 4S
1.4
2.3 2.9
2,3
2.3 3.1
2.2 2.2
2.2
2.4
2.3
2.3
2.3
2.2
2.2
2.4
2.4
2.1
2.2
2,2
2.2
2.4
2.5
2.6
2.5
2.6
2.7
2.7
2.7
2.4
5N
1.8
2.0
2.1
2,0
2.0
1.9
1.9
1.9
2,0
2.1
2,0
1.9
2.0
2.4
2.0
2.2
2,1
2.1
1.7
2.4
2.0
2.2
2.1
2.3
Drain
5M 5S
2.2 2.2
2.2 2.2
2.4 2.2
2.4 2.4
2.3
2.2
2.4
2.3
2,7
2.3
2.4
2.4
2,3
2.3 2.2
2.5
2.7
SAN
2.3
2.5
2.7
2.7
2.7
2.6
2.7
2,5
2.6
2.3
2,4
2.5
2.8
2.7
2.4
2,7
2,5
2,6
3.0
2,0
2.9
SAM 5AS
2.3 2.3
2,5 2.4
2.4
2.5
2,6
2.6
2.5
2,5
2.5
2.6
2.3
2,4
2.6
2.3
2,3
2.6
2,7
2.7
2.6
2.9
2.7
3.0
6N
2.0
2.0
2.6
2.4
1.8
1.8
1.8
1.9
2.7
2.0
1.8
2.1
2.4
2,3
6M 6S
2.5
2.9
2.8
2.5
2.6
2.5
2.7
3.3
2,4
2.8
2.5
2,6
Average 2,1 1,5 2,2 2,7 1.8 2.0 2.2 2,3 2.3 2.2 1,8 2.2 2.9
-------
Table B-10. EC of tile drain effluent on Hullinger farm in 1973.
(mmho/cm)
Date
6-18
6-19
6-20
6-21
6-22
6-25
6-26
6-27
6-28
6-29
7-2
7-3
7-4
7-5
7-9
7-12
7-13
7-16
7-17
7-18
7-19
7-20
7-24
7-25
7-26
7-27
7-30
7-31
8-1
8-2
IN 1M
2.7 3.6
2.6
2.7
2.8
2.8
2.4
2.5
2.5
2.3
2.3
2.3
2N
2.8
2.7
2.9
2.7
2.6
2.6
2.6
2.2
2.3
2.3
2,3
2.4
2.1
2.1
2.0
2,0
2M 3N
3.1 2,1
3.1 2.0
2.0
2.0
2.0
2.0
2.1
1.5
2.0
2.1
1.7
1.6
1.8
1.8
2.0
1,9
1.7
1.8
1,7
1.8
1.7
1.7
1.6
Drain
3M 4N 4M
1.7
1.8
2.4 1.8
2.1 1.7
2.4 1.7
1.8
1,7
1,7
1.7
1.7
1.7
1.7
1.6
1.6
1.8
1.7
1.8
1.8
1,7
1,7
1.7
1.7
1.6
1.6
1.6
1.6
1.6
1,6
1.7
2.2
2,3
2.1
2.2
2.2
2.3
2,3
2.3
2.3
2.1
2.3
2.1
2.4
2.5
2.3
2.3
2.3
2,3
2.3
2.3
2.3
2.1
2.1
2.3
2,2
2.2
2,3
5N
2.0
2.1
2.0
2.0
2.0
1.9
2.0
2.0
2.1
2.0
1.9
1.9
1.8
1.9
1.9
2.1
2.1
1.9
1.9
2.0
1.9
1,9
1,9
1.8
1.9
1.8
1.7
1,7
1,8
1.6
5M
2.3
2.2
2.3
2.2
2.2
2.3
2,8
2,4
2,4
2.3
2.3
2,2
2,3
2,3
2.2
2.3
2.2
2.0
2,0
SAN
2.2
2,3
2.3
2.2
2.3
2.2
2,2
2,2
2.2
2.3
2.3
2.1
2.1
2.2
2,2
2.3
2.2
2.2
1,9
2.1
2,2
2.0
2.0
2.1
1.8
2.1
2.1
2.0
5AM
2.8
2.9
2.8
2.8
2.8
2.6
2.7
2,7
2,7
2.8
2.7
2.6
2.6
2,8
2.9
2.7
2.7
2.7
2.3
2.3
2.6
2.5
2.5
2.5
2.5
2.5
2.5
6N
1.7
1.8
1.8
1.8
1.7
1.6
1.8
1.8
1.8
1.8
1.7
1.7
1.4
1.8
1.9
2.0
1.9
1.8
1.7
1.8
1.8
1.8
1.8
1.7
1.6
1.7
1.6
1.8
1.6
1.6
6M
2.7
2.6
2.7
2.7
2.6
2.3
2.4
2,4
2.5
2.5
2.4
2.4
1.9
2.5
2.5
2.5
2.4
2.3
2.4
2.4
2.2
2.2
2.1
2.1
2.1
2.1
2.1
-------
Table B-10. EC of tile drain effluent on Hullinger farm in 1973 (Continued).
(mmho/cm)
Date IN
8-6
8-7
8-8 2.9
8-9
8-10
8-13
8-14
8-15
8-16
8-17
8-20
8-21
8-22 2.5
8-23 2.5
8-27 2.2
8-28
8-29
9-3
9-4
9-5 2.8
9-6
9-7 2.5
9-12
9-13
9-14
Average 2.5
1M 2N
2,1
2.7
2.5
2.5
2,4
2.3
2.0
2.5
2.4
2,3
2.2
2.1
2.1
3.6 2.4
2M
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
3.7 1
3.5 1
1
1
1
1
3.4 1
3N 3M
.8
.6
.7
.8 2.3
.6
.6
.7
.7
.7
.8
,0 2.2
.9 2,2
.8 2,2
.6
.7
.7
.7
.7
.6
.7
.9 2.4
.9 2.2
.8
.9
.7
.8 2,3
Drain
4N 4M
1.7
1.6
1.6
1.6
1.7
1.5
1.7
1,6
1.6
1.6
1.7
1.7
1.7
1.7
1.6
1.6
1.6
1.6
1.6
1.6
1.6
1,7
1.7
1.8
1.8
1,7
2.3
2.3
2.3
2.3
2.2
2.1
2.2
2.2
2.2
2.2
2.3
2,2
2.2
2,2
2.1
2.1
2.2
2.3
2.3
2.3
2.3
2.3
2.3
2.3
2.2
2.2
5N
1.8
1.8
1.8
1.7
1.6
1.5
1.7
1.7
1.6
1.7
1.6
1.7
1.7
1,6
1.6
1.6
1.7
1.6
1,7
1.7
1.6
1.7
1.7
1.7
1.7
1.8
4M
2.1
1.9
1.8
2,1
2,0
2.0
2.0
1.9
2.2
2,1
2,1
2.0
1.9
1.9
1,9
1.9
1,9
1.9
1.9
2.1
SAN
1.9
2,1
2.2
2.2
1.8
2.0
2.0
1,9
1.8
1.8
1.8
1.6
1,8
1.7
1.8
1.8
1.8
1.8
1.8
1.8
1.8
1.9
1.9
1.9
1.9
2,0
SAM
2.5
2.2
2.4
2.4
2,4
2.3
2.4
2.3
2.4
2,3
2,2
2,1
2.2
2.2
2.2
2.2
2.2
2.2
2.2
2.3
2.3
2.2
2,5
6N
1.9
1.7
1.9
1.9
1,7
1.6
1.7
1.6
1.6
1.6
1.6
1.7
1,7
1.6
1.6
1.7
1.7
1.7
1.8
1.8
1.8
1.8
1.9
1.9
1.9
1.7
6M
2.3
2,1
2.1
2,1
2.0
2.0
2*0
2.2
2.2
2.0
2.0
2.0
2.0
1.9
2.0
2.0
2.0
2.0
2.1
2.2
2.2
2.2
-------
Table B-ll.
Electrical conductivity of samples withdrawn from ceramic
cups (106 cm depth.) in commercial fertilizer plots
treated with Ca(N03>2 in 1972.
(mmho/cm)
7-14
Alfalfa 3N1
Alfalfa 3N2
Alfalfa 3M2
Alfalfa 3S2
Alfalfa 4N1
Alfalfa 4N2
Alfalfa 4M1
Alfalfa 4M2
Alfalfa 4S1
Alfalfa 4S2
Corn 5N1
Corn 5N2
Corn 5M1
Corn 5M2
Corn 5S1
Corn 5S2
Corn 5AN1
Corn 5AN2
Corn 5AM1
Corn 5AM2
Corn 5AS1
Corn 5 AS 2
Corn 6N1
Corn 6N2
Corn 6M1
Corn 6M2
Corn 6S1
Corn 6S2
4.
4.
3.
5.
1.
3.
3.
3.
3.
3.
4.
3.
4.
2.
3.
3.
3.
3.
2.
2.
2.
2.
1.
4.
0
6
4
3
7
6
9
-
9
-
4
3
3
5
7
7
7
8
3
6
.
9
4
9
7
8
7-22
3.
3.
2.
3.
2.
2.
3.
2.
2.
2.
3.
3.
3.
2.
2.
2.
2.
2.
3.
2.
.
2.
2.
3.
3.
3
5
-
0
2
8
3
5
-
8
4
1
1
3
1
3
4
9
4
4
2
5
1
0
2
4
7-28
3.4
3.8
3.6
4.1
1.8
2.9
2.2
2.8
3.1
3.2
2.8
3.1
3.4
3.6
3.4
3.3
3.0
3.2
2.8
3.5
3.2
2.4
8-4
2.6
3.6
1.5
2.5
2.7
2.8
3.3
7.5
2.7
3.3
2.8
3.0
4.0
2,9
3,0
3.1
3.0
1/\
,y
2.2
2.0
1.7
3.4
Date
8-10
4.1
4.0
4.4
5.2
1.9
3.3
4.1
3,3
3.8
5.6
4.1
4.4
4.4
4.0
4.2
4.5
3.1
2.7
4.5
3.8
3.4
3.6
3.9
3.5
2.3
3.9
3.5
8-19
3.8
4.2
2.9
5.4
2.9
4.0
3,8
4.2
3.9
4.6
1.2
3.9
4.2
4.7
3.4
2.9
4.3
4.3
3.5
4.0
2.9
3.1
2.5
3.9
3.7
8-24
4.0
4.3
4.6
6.4
2.7
3.7
4.1
3.7
4.4
3.9
4.5
3.9
4.1
4.8
3.1
2.8
4.3
4.1
3.5
3.8
3.7
2.9
2.5
4.0
3.7
9-6
3,7
3.5
4.4
6.1
3.0
4.1
3.8
4,7
3,7
3.3
3.3
2.8
2.3
4.1
3.7
3.7
3.8
3.7
2.3
2.5
4.0
3.7
9-18
_>__
5.0
7.7
2.8
4.1
4.5
4.2
4.6
4.1
4,6
3.8
2.8
0.9
4,3
4.2
3.6
4.0
3.2
2.7
2.7
4.2
3.6
133
-------
Table B-12.
Electrical conductivity of samples withdrawn from
ceramic cups (76 and 106 cm depths) in commercial
fertilizer plots treated with NH.NO, in 1973.
(mmho/cm)
Alfalfa 3M1
Alfalfa 3M2
Alfalfa 4N1
Alfalfa 4N2
Alfalfa AMI
Alfalfa 4M2
Corn 5N1
Corn 5N2
Corn 5M1
Corn 5M1
Corn 5AN1
Corn 5AN2
Corn 5AM1
Corn 5AM1
Corn 6N1
Corn 6N2
Cora 6M1
Corn 6M2
7-17
___
3.2
2.5
4.2
3.4
4.3
3.3
3.2
2.8
4.2
2.2
3.6
3.5
3.0
3.9
2.3
76
7-30
_._
4.3
2.2
4.2
3.2
2.3
3.3
3.3
4.2
2.6
3.6
3.5
3.0
3.9
0
cm depth
8-10
3.8
4,7
2.2
4.2
3.5
2.8
3.3
3.2
3.0
4.3
2,3
2.3
2.6
3.2
2.9
4.0
2.2
8-23
4.
4.
2.
4.
3.
3.
3.
3.
2.
4.
2.
2.
3.
3.
3.
2.
6
7
2
1
6
3
3
3
9
3
4
3
7
0
2
-
2
Date
9-5
3.9
4.4
2.2
3.7
3.8
3.1
3.2
3.3
2.6
4.3
2.4
2.3
3.9
3,1
3.3
3.0
2.2
7-17
2.6
2.2
3.4
4.0
4.2
3.2
3.7
3.5
2.8
3.1
2.2
3.6
5.1
2.6
106 cm depth
7-30
___
3.8
2.5
4.5
3.7
2.8
3.9
1.9
3.5
4.1
2.7
8-10
1.3
4.1
3.8
4.3
4.3
1.8
3.7
3.8
2.8
3.0
3.7
2.1
2.4
2.8
4.2
2.8
3.3
2.7
8-23
1.8
3.5
3.8
4.4
4.4
2.3
4.0
3.9
2.8
3.2
4.0
2.3
2.3
1.8
4.1
2.3
4.1
2.5
9-5
__.
3.7
3.7
4.4
4.8
1.8
4.1
4.0
2.7
4.0
4.3
2.4
3.9
2.8
4.1
2.5
4.3
2.3
134
-------
Table B-13. Computations of EC derived from measurements with the 4-probe field system during 1972 field
trials in Vernal.
Depth Interval (cm)
Date
8-8
8-9
8-9
8-9
8-9
8-10
8-10
8-10
8-10
8-10
8-11
8-11
8-18
9-18
9-19
9-19
9-19
9-19
9-19
9-19
9-19
9-20
9-20
9-20
9-20
9-20
9-20
9-21
9-21
Time
1540
0700
0935
1150
1655
0730
0810
0915
1210
1610
0835
1420
1400
1700
0815
1040
1150
1300
1400
1510
1785
0740
1100
1345
1420
1535
1733
0805
1325
0-15
1.0
.74
1.57
1.60
1.73
1.62
1.86
1.57
1.71
1.73
1.55
1.67
1.23
.82
1.08
1.15
1.75
1.57
1.67
1.67
1.68
1.61
1.54
1.35
1.36
1.41
1.35
1.09
1.28
15-30
1.1
1.2
1.85
1.81
1.85
1.88
2.01
1.70
1.63
1.62
1.60
1.52
2.28
1.67
1.22
1.23
1.86
1.77
1.88
1.72
1.88
1.79
1.63
1.49
1.48
1.54
1.50
1.47
1.44
30-46
1.36
1.77
1.43
1.39
1.46
1.68
1.50
1.90
1.91
1.89
2.03
1.93
2.00
1.21
1.30
1.30
1.85
1.88
1.92
1.93
2.05
1.85
1.84
1.58
1.46
1.53
1.62
1.47
1.49
46-61
1.67
2.38
1.80
1.82
1.74
2.22
1.88
1.83
1.71
1.71
2.13
1.97
3.12
.78
1.87
2.01
2.14
2.10
2.16
2.32
2.30
2.70
2.41
1.43
1.64
1.67
3.69
1.95
1.78
61-76
2.19
0.88
1.23
1.19
1.18
1.27
1.11
1.16
1.21
1.20
1.34
1.18
2.51
.79
2v03
1.91
1.73
1.69
1.78
1.64
1.66
1.76
1.63
1.50
1.49
1.52
1.52
1.56
1.46
76-91
1.54
2.22
1.45
1.56
1.37
1.66
1,32
1.29
1.37
1.17
1.39
1.27
3.29
3.97
1.88
1.93
1.73
1.91
1.83
1.99
1.78
2.13
1.76
1.12
1.74
1.90
2.15
1.82
1.70
91-107
1.51
1.10
.87
.88
.81
.80
1.00
1.16
1.15
1.06
1.22
1.13
2.88
.68
2.00
1.70
1.21
1.35
1.54
1.61
1.54
1.62
1.59
.88
1.40
1,36
1.22
1.41
1.59
107-122
.74
2.10
.80
.97
1.15
1.28
.76
1.18
.82
1.19
1.34
1.13
1.51
2.64
1.80
2.40
1.28
1.24
1.34
1.00
1.50
1.92
1.96
1.30
1.21
1.51
1.52
1.98
1.89
122-137
2.02
.90
1.02
1.10
.97
.85
.75
.78
.89
.79
.95
.95
.93
2.24
1.94
1.59
.69
.89
.91
1.31
.85
1.30
1.09
.59
1,00
.96
1.07
1.35
1.26
137-152
1.33
.70
.58
.78
1.01
.47
.87
.87
1.00
,88
1.15
.97
1.23
.27
.55
1.10
.74
.96
.98
.90
1.08
.96
,92
.73
1.07
1.04
1.06
.09
1.06
152-168
.27
.63
.56
.37
.36
1.09
.37
.62
.84
.59
.62
.47
.79
1.53
1.25
1.10
.61
.55
.72
.62
.88
.93
.75
.73
.92
.78
1.13
1.99
.99
168-183
.63
.81
.34
.33
.52
.56
.66
.53
.42
.42
.69
.75
.60
.47
1.33
1.09
.74
.86
.78
.94
1.05
.93
1.03
.52
.62
.78
.74
.63
.76
EC = K4P/6 (500 0 - 40) where K4P are in mmho/cm and 0 = water content (fraction).
-------
Table B-14, Initial (6-28) and final (10-7) soil tests in plots 1972
for N-N03.
(ppm)
Plot
3N1
3N2
3M2
3S1
4N1
4N2
4M1
4M2
4S1
4S2
5N1
5N2
5M1
5M2
5S1
5S2
5AN1
5AN2
5AM1
5AM2
5AS1
5AS2
6N1
6N2
6M1
6M2
6S1
6S2
30 on
Initial
.7
1.1
.6
1.3
1.0
5.1
9.5
28.2
12.8
9.3
20.0
38.4
85.6
56.4
19.4
55.8
15.4
12.6
75.9
120.9
15.0
7.0
9.6
.6
3.6
9.0
7.7
.4
Final
4.4
2.1
1.8
1.0
1.2
4.6
4.4
3.5
3.2
2.8
3.8
3.8
8.3
54.3
2.6
3.6
70.5
125.0
10.5
4.5
112.2
75.8
4.4
6.0
1.9
6.3
2.4
.5
60 cm
Initial
l.Q
.1
3.5
1.6
5.8
60.6
70.1
119.9
22.6
28.2
6.1
9.2
1.0
1.8
18.0
.9
.5
.9
1.6
1.4
.5
1.6
.5
.4
.1
2.0
.3
1.3
Final
4.3
.4
.6
.7
2.8
2.8
40.4
2.0
3,6
2.0
1,2
1.1
1.7
66.2
4.4
1.8
68.0
87.0
26.3
69.0
86.0
.6
.9
.6
1.0
.9
.8
1.5
90 cm
Initial
.4
2.2
.4
1.0
.8
2.1
.7
2.3
1.J
4.4
2.0
1.0
1.0
1.0
2.2
2.0
.9
1.2
.8
1.2
1.4
1.4
.2
.1
.2
.2
.1
.9
Final
1.0
.8
1.0
.6
.7
.9
49.0
12.8
28.3
1.2
2.3
0
26.2
15.3
7.5
3.4
24.8
56.8
28.7
90.5
115.5
96.2
1.2
1.2
.9
1.1
.3
1.2
120 cm
Initial
1.2
1.6
.6
1.5
1.0
2.4
.5
1.2
1.1
1.7
1.0
2.9
1.1
.2
1.0
1.3
1.4
2.5
1.6
2.9
1.5
2.9
5.1
.5
.4
.3
.3
1.3
Final
.6
.6
5.5
.4
.7
.8
13.8
.9
6.9
1.1
7.1
1.4
83.0
21.4
18.6
15.8
104.5
78.2
18.0
33.8
82.2
2.7
3.4
1.7
4.2
.9
.5
1.6
136
-------
Table B-15. Initial (6-20) and final (9-19) soil tests in plots 1973 for
(ppm)
Plot
3M1
3M2
4N1
4N2
4M1
4M2
4S1
4S2
5N1
5N2
5M1
5M2
5S1
5S2
5AN1
5AN2
5AM1
5AM2
5AS1
5AS2
6N1
6N2
6M1
6M2
6S1
6S2
30
Initial
5.0
7.5
8.8
19.5
75.0
38.3
43.8
20.0
59.3
41.3
165.0
163.8
144.3
92.5
43.8
74.0
132.0
142.5
52.8
37.5
20.5
32.8
28.0
18.0
24.5.
24.5
cm
Final
3.8
2.8
2.8
2.9
2.9
7.5
3.1
2.0
28.3
28.3
38.3
34.5
26.8
9.3
7.1
7.8
10.8
14.5
2.8
3.9
7.6
4.5
3.5
3.4
3.1
3.0
60
Initial
3.3
6.0
7.0
23.5
18.8
32.5
18.8
21.3
18.8
19.3
36.8
20.5
10.8
22.5
9.3
47.8
28.3
29.3
20.0
9.5
9.3
18.0
13.8
8.3
5.0
6.3
cm
Final
.6
.6
.4
.8
1.0
81.8
1.1
1.5
6.5
6.4
63.0
62.0
99.5
38.8
7.8
8.3
69.3
69.5
1.8
10.5
2.3
1.0
2.0
1.0
.8
1.0
90
Initial
.8
3.6
.8
.8
3.8
6.3
4.3
4.3
4.5
5.3
32.5
16.8
9.6
11.1
3.5
7.0
19.8
40.0
5.0
8.7
6.0
3.4
5.8
3.8
4.3
5.5
cm
Final
1.3
.4
1.3
1.3
18.3
4.4
15.8
4.3
2.0
2.3
4.5
24.0
20.3
10.0
13.8
4.3
33.8
47.5
.8
7.5
4.0
2.3
.8
1.5
.6
.5
120
Initial
.4
.5
.4
.5
6.3
1.8
1.8
1.9
5.2
5.4
9.0
32.5
35.0
20.3
2.7
3.4
14.0
26.4
6.2
5.8
3.3
3.1
8.1
3.4
3.9
2.9
cm
Final
.6
.5
.3
.1
8.6
1.6
.5
.1
.3
1.3
1.6
10.5
5.1
12.4
4.1
1.6
12.4
28.5
1.5
6.1
2.1
.5
2.0
3.3
.4
.8
137
-------
Table B-16.
N-N03 in commercial fertilizer plots treated with various
rates of NH/NC>3 collected from ceramic samplers in 1973 from
76 cm and 106 cm depths.
(ppm)
Alfalfa 3KL
Alfalfa 3M2
Alfalfa 4N1
Alfalfa 4N2
Alfalfa 4M1
Alfalfa 4M2
Corn 5N1
Corn 5N2
Corn 5M1
Corn 5M1
Corn 5AN1
Com 5AN2
Corn 5AM.
Corn 5AM2
Corn 6N1
Corn 6N2
Corn 6M1
Corn 6M2
7-17
0
1
0
1
4
8
15
48
137
11
133
114
10
33
9
7-30
76
_
2
0
0
1
11
2
11
160
31
100
113
14
15
8-10
8-23
Date
9-5
7-17
cm depth
0
0
0
0
1
9
5
8
44
5
5
62
76
28
29
6
5
0
0
0
1
8
1
9
35
101
6
5
81
23
21
2
1
0
0
0
0
28
0
4
17
122
8
5
109
72
12
4
2
1
0
0
2
4
69
26
15
42
61
21
129
132
18
,
7-30
106
0
3
86
7
37
3
9
105
21
21
«
8-10
8-23
9-5
cm depth
0
1
0
33
59
1
2
36
28
22
15
48
49
10
17
24
5
0
1
0
6
17
76
8
2
27
54
35
9
38
30
25
5
15
2
0
0
0
42
30
11
2
14
81
56
8
83
72
34
1
11
138
-------
Table B-17. N-NO-j in commercial fertilizer plots treated with
various rates of Ca(N03)2 collected from ceramic samplers
(106 cm depth) in 1972.
(ppm)
Alfalfa 3N1
Alfalfa 3N2
Alfalfa 3M2
Alfalfa 3S1
Alfalfa 4N1
Alfalfa 4N2
Alfalfa 4M1
Alfalfa 4M2
Alfalfa 4S1
Alfalfa 4S2
Corn 5N1
Corn 5N2
Corn 5M1
Corn 5M2
Corn 5S1
Corn 5S2
Corn 5AN1
Corn 5AN2
Corn 5AKL
Corn 5AM2
Corn 5AS1
Corn 5 AS 2
Corn 6N1
Corn 6N2
Corn 6M1
Corn 6M2
Corn 6S1
Corn 6S2
7-14
1
1
0
1
0
0
0
0
0
0
0
0
0
1
0
0
15
18
1
1
1
0
6
7-22
1
0
0
0
0
0
1
41
0
0
0
0
19
3
1
2
2
1
3
8
1
1
0
1
8
7-28
1
0
0
1
0
0
0
1
1
7
1
6
15
1
9
10
1
10
1
6
20
-~
0
Da
8-4
1
0
0
0
0
0
1
19
33
52
12
0
5
32
16
25
49
5
1
0
15
.te
8-10
0
0
1
0
0
0
0
0
0
3
83
82
94
21
102
21
68
10
99
16
3
40
57
9
1
2
9
8-19
1
1
1
2
0
2
12
1
71
91
1
19
109
10
106
60
110
23
5
46
58
6
1
3
4
8-24
1
3
1
1
1
1
0
3
0
-
70
82
15
50
50
80
49
125
25
6
48
59
6
1
4
2
9-6
1
0
0
1
1
4
75
65
44
62
59
56
7
111
21
9
17
52
0
1
4
1
9-18
1
1
1
0
0
0
11
0
69
35
40
43
0
84
20
9
12
53
1
1
1
0
139
-------
Table B-18. N-NCL of tile drain effluent on Hullinger Farm in 1972.
(ppm)
Date 3N
6-28
6-29
6-30
7-3
7-5
7-7
7-10
7-11 0.1
7-12
7-13
7-14
7-17
7-18
7-19
7-20
7-21
7-22
7-25
7-26
7-27
7-28
7-31
8-1
8-3 0.1
8-4 0.1
8-7
8-8
8-9 0.2
8-10 0.1
8-11 0.2
4N
0.4
0.9
0.7
0.6
0.6
0.5
0.7
0.8
0.5
0.5
0.6
0.7
0.5
0.6
0.7
0.9
0.9
0.8
0.8
AM
0.3
0.2
0.6
0.6
0.4
0.4
3.7
2.9
4.4
1.0
1.0
0.8
0.9
0.8
0.6
0.7
0.8
0.8
0.8
4S 5N
0.4
0.3
0.6
0.5
0.5
1.1
1.6
1.7
1.4
0.9
5.3
4.2
5.0
3.4
2.7
8.3
5.4
6.3
9.1
5.7 7.3
5M
0.3
0.2
0.5
1.2
0.9
1.2
1.0
6.4
6.0
5.8
14.4
15.8
16.4
19.4
16.1
Drain
5S
3.2
3.2
3.5
6.1
6.1
12.8
6.1
6.9
SAN
0.4
1.6
0.6
0.2
0.6
0.3
2.4
3.4
2.0
5.3
5.5
5.4
5.7
5.3
9.2
9.0
14.2
17.3
17.3
SAM
0.2
0.5
0.8
0.4
0.5
0.2
5.5
1.9
1.4
8.0
8.0
5.6
3.9
4.5
11.3
13.2
9.1
11.0
9.4
5AS
1.8
3.7
3.1
3.4
6.0
5.7
0.1
0.1
5.5
4.9
5.0
6N
0.1
0.1
0.1
0.4
0.1
0.5
0.7
0.1
1.3
1.4
1.3
1.2
1.9
2.8
2.4
2.4
3.4
0.1
3.8
112.8
3.1
8.3
0.1
0.1
6.1
9.1
5.1
6M
0.2
0.1
0.3
0.2
0.1
0.4
0.4
0.5
0.6
2.3
1.6
3.0
1.1
4.3
3.4
3.2
5.4
0.1
0.1
7.6
5,4
6S
1.6
3.6
-------
Table B-18. N-NO3 of tile drain effluent on Hullinger Farm in 1972 (Continued)
(ppm)
Date 3N
8-15
8-16
8-17
8-18 0.4
8-21 0.1
8-22 0.1
8-24
8-25
8-28
8-30
8-31
9-1
9-2
9-3
9-4
9-5
9-7 0.8
9-8 0.1
9-11
9-12
4N
1.4
1.4
1.4
2.3
0.8
1.1
0.8
0.6
0.7
1.1
0.7
0.6
0.8
0.7
1.1
0.8
1.0
0.6
0.6
4M 4S
3.4
3.6 5.2
4.8 1.1
20.8
3.3
3.3
3.1
4.2
4.9
4.5
7.5
6.2
6.6
6.2
5.4
6,5
5.0
3.7
2.9
5N
7.5
5.3
4.3
3.9
4.0
4.3
3.7
6.1
5.2
4.2
3.9
4.0
4.9
5.5
5.1
3.0
2.8
Drain
5M 5S
21.6 21.7
23.2 7.5
13.8
8.1
23.0
18.5
24.3
24.1
20.7
16.7
8.7
18.1 11.3
SAN
15.2
14.5
8.6
9.7
13.1
12.2
13.4
13.7
15.0
18.0
17.5
18.1
19.0
19.0
19.4
18.6
17.3
SAM
8.1
6.8
7.6
10.5
10.0
9.5
9.6
10.3
7.1
6.5
11.0
11.4
11.4
10.3
9.7
9.8
8.7
5AS 6N
3.9
5.8
5.6
3.9
5.0
5.1
5.2
10.0
6.1
5.5
5.7
6.7
8.9
6M 6S
8.0
6.2
5.6
6.6
8.4
19.0
7.6
6.7
7.9
7.8
9-13 0.5 4.3 5.0 10.8
9-14 0.4 5.5 3.9 9.9 11.1
9-15 0.1 0.5 5.6 3.9 10.2 9.4
9-16 0.3 6.2 3.6 18.8 10.0
-------
Table B-19. N-NO of tile drain effluent on Hullinger Farm in 1973.
(ppm)
Date
6-18
6-19
6-20
6-21
6-22
6-25
6-26
6-27
6-28
6-29
7-2
7-3
7-4
7-5
7-9
7-12
7-13
7-16
7-18
7-19
7-20
7-24
7-25
7-26
7-27
7-30
8-1
8-2
8-6
8-7
8-8
8-9
8-10
8-13
8-14
8-15
8-16
8-17
8-20
8-21
8-22
8-23
8-27
4N
1.5
2.0
0.8
1.2
1.9
1.1
1.0
0.3
1.1
1.2
1.2
1.1
1.1
1.2
1.3
1.1
1.1
1.7
1.1
1.0
1.0
0.9
0.9
1.0
4M
4.3
0.7
4.1
2.5
4.0
1.7
0.6
1.3
3.6
3.4
3.7
3.5
3.3
3.3
3.5
3.2
3.5
3.5
4.1
3.9
3.2
3.0
2.8
4.0
3.4
5N
3.6
1.4
3.0
2.2
4.9
3.6
4.4
4.5
5.2
4.5
3.4
3.5
3.5
3.0
3.0
3.3
3.1
3.1
3.0
3.7
2.4
1.7
1.7
1.7
1.7
1.7
Drain
5M
18.8
5.5
9.2
5.1
18.5
16.1
16.1
16.3
16.1
7.6
14.9
10.9
9.1
7.5
5.7
11.1
8.1
SAN
9.7
9.5
5.5
9.0
9.3
8.8
8.4
6.6
8.4
9.3
8.4
8.2
8.3
7.8
7.5
8.7
7.4
8.4
9.2
8.6
6.4
5.5
4.9
5.2
4.7
5AM
32.8
13.0
21.8
23.2
31.0
31.5
34.3
21.3
29.1
28.9
33.2
27.8
31.4
29.5
29.9
28.1
31.7
27.9
24.8
18.7
17.5
16.6
16.6
13.5
6N
6.6
2.4
4.0
3.0
7.0
6.6
7.7
9.3
11.0
9.1
9.1
8.6
9.5
9.8
15.1
16.1
16.6
18.5
18.0
11.2
8.6
8.6
11.1
12.3
10.2
6M
6.6
3.3
3.0
3.3
5.7
5.0
5.5
5.7
5.8
5.2
5.2
5.3
4.7
6.7
4.5
7.1
4.8
4.1
5.7
3.5
4.6
3.1
142
-------
Table B-19. N-NO of tile drain effluent on Hullinger Farm in 1973
(Continued).
(ppm)
Date
8-28
8-29
9-3
9-4
9-5
9-6
9-7
9-12
9-13
9-14
4N
0.8
0.8
0.8
0.7
0.7
0.8
4M
3.2
2.3
3.1
4.2
4.0
3.8
5N
1.7
1.4
1.6
1.0
1.5
1.6
Drain
5M
1.5
4.4
2.8
2.6
SAN
5.2
4.8
5.0
5.2
5.2
4.8
SAM
11.2
10.0
9.5
9.8
9.1
9.8
6N
11.8
11.1
12.7
12.3
13.9
14.8
6M
3.1
3.4
3.5
3.6
4.5
4.8
143
-------
Table B-20. Initial and final soil tests in manure plots 1972 for N-NO .
(ppm)
30 cm
Before After
Al Corn
A2 Corn
A3 Bare
A4 Corn
A5 Corn
A6 Corn
Bl Corn
B2 Corn
B3 Bare
B4 Corn
B5 Corn
B6 Corn
Cl Corn
C2 Corn
C3 Bare
C4 Corn
C5 Corn
C6 Corn
Dl Corn
D2 Corn
D3 Bare
D4 Corn
D5 Corn
D6 Corn
El Sudan
E2 Sudan
E3 Bare
E4 Sudan
E5 Sudan
E6 Sudan
Fl Sudan
F2 Sudan
F3 Bare
F4 Sudan
F5 Sudan
F6 Sudan
Gl Sudan
62 Sudan
G3 Bare
G4 Sudan
G5 Sudan
G6 Sudan
HI Sudan
H2 Sudan
H3 Bare
H4 Sudan
H5 Sudan
H6 Sudan
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Grass
120
240
0
60
0
120
0
60
60
120
240
60
240
120
120
0
60
0
60
0
240
240
120
240
0
240
0
120
0
60
120
60
60
0
240
120
240
120
120
240
60
0
60
0
240
60
120
240
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
67.8
.0
10.9
38.5
9.9
60.5
22.3
58.3
24.0
125.0
146.2
10.8
.0
16.9
70.0
124.9
23.9
9.0
43.7
13.5
41.2
19.7
15.2
38.7
5.9
13.6
4.7
12.6
12.7
31.8
4.8
3.6
4.6
10.2
47.5
26.0
15.0
3.6
11.7
12.3
18.6
4.4
11.0
2.2
5.2
3.8
72.3
37.7
22.3
17.7
8.8
6.2
2.9
43.7
2.6
10.2
18.5
30.0
46.7
5.6
4.8
23.0
25.5
3.7
7.6
14.8
13.0
3.8
30.5
81.8
6.4
82.7
4.0
17.1
12.0
9.9
4.2
11.0
12.7
8.0
70.5
3.3
5.7
9.0
8.3
6.7
10.2
7.3
6.9
2.2
32.4
3.4
14.5
9.1
4.9
40.4
60 cm
Before After
3.0
1.8
9.8
3.0
4.2
5.0
.0
24.4
13.8
1.8
5.0
1.4
5.4
3.8
2.6
7.1
4.1
2.9
2.5
3.2
3.9
5.9
4.2
7.1
1.9
2,2
.3
2.0
1.3
.2
.5
1.2
.1
.7
2.1
.4
1.4
1.8
2.2
2.4
1.3
1.5
4.6
1.6
2.8
1.7
2.4
2.8
37.3
8.7
5.7
3.0
.9
48.4
1.5
3.0
3.2
9.6
29.4
2.4
1.8
27.8
14.8
2.7
1.8
3.2
6.7
1.0
25.1
27.5
4.5
84.3
.7
27.5
12.2
1.7
.7
1.6
18.1
2.6
25.7
.8
8.6
9.7
6.8
12.5
7.2
2.5
20.8
.6
6.5
.8
.6
2.8
4.0
3.6
90 cm
Before After
1.1
1.1
2.4
.3
.1
3.2
1.1
2.5
1.4
.9
2.3
.2
3.3
1.5
1.3
1.8
1.1
1.0
.9
1.0
2.8
1.1
3.1
4.4
.1
5.6
.4
.4
.4
.3
1.1
.3
.2
1.2
.6
.2
2.0
1.0
1.2
.9
1.4
1.5
2.8
2.2
1.7
1.0
1.6
1.3
43.9
.2
11.8
12.1
1.4
47.9
1.6
2.5
8.8
5.4
46.7
.3
2.9
37.8
11.3
2.6
4.8
5.6
16.1
2.2
.0
58.8
30.0
84.3
.8
10.2
9.6
1.2
.6
.7
18.1
2.4
14.8
.1
27.5
8.2
5.6
12.8
4.1
1.7
10.3
1.8
3.4
1.4
1.0
3.2
9.0
25.4
120 cm
Before After
1.6
1.9
3.4
.9
.5
1.7
.4
.3
.1
.6
1.6
.1
2.6
.3
.5
1.4
.1
2.3
1.7
.4
1.1
.4
1.8
1.2
.4
.1
.2
.6
1.1
.5
.1
.1
.2
.3
.3
1.4
.7
1.3
1.0
1.6
1.6
.6
.9
.8
1.4
1.3
9.9
1.4
43.9
35.4
5.8
25.4
7.2
3.4
4.8
7.6
9.6
10.5
25.5
4.4
3.2
65.5
17.9
3.4
5.5
10.8
45.5
8.8
9.2
45.5
28.5
61.8
3.6
.6
9.9
9.3
1.2
12.7
9.1
1.0
14.1
.7
30.8
5.4
2.5
4.0
6.9
.1
8.5
4.4
5.4
2.0
.5
22.9
38.4
38.4
144
-------
Table B-21. N-N03 in the manure plots in 1972 collected from ceramic
samplers at 106 cm.
(ppm)
Date
Bare (0)a A3
Bare (0)a E3
Bare (54) a B3
Bare (54) a 5-3
Bare (108) a C3
Bare (108) a G3
Bare (216) a D3
Bare (216) a H3
Corn A5
Corn Bl
Corn C4
PriT-n Cf\
viUi.ll uU
Corn D2
Corn (54) a A4
Corn (54) a B2
Corn (54) a B6
Corn (54)a C5
Corn (54) a Dl
Corn (108) a Al
Corn (108)a A6
Corn (108)a B4
Corn (108 )a C2
Corn (108)a D5
Corn (216)a A2
Corn (216)a B5
Corn (216)a Cl
Corn (216)a D4
Corn (216)a D6
Sudan (0) El
Sudan (0) E5
Sudan (0) Fl
Sudan (0) H2
Sudan (0) 66
7-14
8
11
___
5
7
16
19
5
10
1
5
7-22
1
7
8
1
47
22
49
8
5
11
23
.
7
3
21
18
7
93
6
40
1
29
5
5
7-28
10
8
7
13
12
2
8
10
1
9
7
7
___
29
140
11
18
3
32
6
8-4
74
18
83
37
5
113
1
_
47
15
67
60
21
6
35
168
56
139
72
43
25
36
8-10
74
34
145
50
106
18
1
130
65
34
86
63
41
15
67
120
124
211
65
,
6
29
22
8-19
74
52
174
60
104
12
255
0
94
82
44
43
74
149
68
19
94
97
102
185
236
96
102
21
23
26
41
8-23
38
53
152
61
110
47
248
1
72
96
30
49
71
125
54
117
82
___
121
129
253
256
110
23
73
32
29
42
9-7
41
61
145
66
84
71
226
1
18
73
65
60
140
154
101
___
97
164
154
26
32
9-18
36
53
112
74
78
84
189
0
3
49
8
69
58
125
108
154
106
_ _ _
90
118
308
289
186
96
9
84
2
38
145
-------
Table B-21. N-NO- in the manure plots in 1972 collected from ceramic
samplers at 106 cm (Continued).
(ppm)
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
(54)a E6
(54)a F6
(54)a G5
(54)a HI
(54)a H4
(108)a E4
(108)a F4
(108 )a G2
(108)a H5
(108)a F5
(216)a E2
(216 )a F2
(216)a Gl
(216)a G4
(216 )a S3
7-14 7-22
._
0
9 6
2 1
4
_
___
0 0
5
1 1
0
7-28
B^^B
0
0
4
___
0
11
0
Date
8-4 8-10
««_^_
10
10
16
0
1
__
24
22
38
0
115
10
20
1
8-19
68
17
33
2
53
23
48
0
130
7
36
25
52
0
8-23
68
12
43
26
64
73
43
1
141
11
___
39
0
76
1
9-7
__ _
61
80
45
35
1
1
9-18
48
68
22
60
84
22
0
114
45
26
4
99
0
aManure application in mt/ha (dry weight)
146
-------
Table B-22. Initial and final soil tests in manure plots in 1973 for N-NO .
J
(ppra)
30 cm
Before After
Al Corn
A2 Corn
A3 Bare
A4 Corn
A5 Corn
A6 Corn
Bl Corn
B2 Corn
B3 Bare
B4 Corn
B5 Corn
B6 Corn
Cl Corn
C2 Corn
C3 Bare
C4 Corn
C5 Corn
C6 Corn
Dl Corn
D2 Corn
D3 Bare
D4 Corn
D5 Corn
D6 Corn
El Corn
E2 Corn
E3 Bare
E4 Corn
E5 Corn
E6 Corn
Fl Corn
F2 Corn
F3 Bare
F4 Corn
F5 Corn
F6 Corn
Gl Corn
G2 Corn
G3 Bare
G4 Corn
G5 Corn
G6 Corn
HI Corn
H2 Corn
H3 Bare
H4 Corn
H5 Corn
H6 Corn
120
240
0
60
0
120
0
60
60
120
240
60
240
120
120
0
60
0
60
0
240
240
120
240
0
240
0
120
0
60
120
60
60
0
240
120
240
120
120
240
60
0
60
0
240
60
120
240
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
T/A
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
(72)
71.8
57.5
19.5
34.3
30.0
52.0
15.5
47.0
35.0
71.8
113.8
46.8
60.0
34.5
43.0
31.3
33.0
37.5
37.0
20.8
35.0
65.0
60.5
61.3
25.0
120.5
27.5
100.8
21.8
65.8
100.8
55.8
76.3
32.5
132.0
62.0
95.0
82.5
67.0
98.3
101.5
26.5
98.3
19.5
107.5
46.8
52.0
63.8
20.2
29.5
10.5
7.5
4.8
37.0
4.0
17.1
17.0
20.8
48.3
7.1
55.8
30.0
39.5
3.0
12.0
17.6
45.8
2.3
55.8
62.0
42.0
103.8
3.6
92.0
14.5
67.0
3.9
41.3
77.0
27.0
52.0
4.9
59.5
63.3
54.5
31.3
81.8
60.0
65.8
6.9
32.0
3.5
70.0
18.5
41.3
70.0
60
Before
29.0
39.5
7.5
19.5
21.3
16.3
5.0
18.8
20.0
33.8
65.0
17.3
25.3
35.0
35.0
14.5
12.0
23.3
20.5
6.2
49.3
38.3
30.8
28.3
8.0
77.3
14.5
34.5
7.0
23.0
48.5
16.8
37.3
12.5
43.8
24.5
28.7
66.8
21.3
26.3
47.0
11.3
25.3
7.5
11.8
7.5
26.3
27.8
cm
After
9.5
18.9
7.8
3.1
5.8
55.5
2.3
18.4
17.0
16.3
22.9
5.0
44.5
35.5
34.5
2.1
4.5
25.5
42.0
4.0
38.3
66.8
46.8
65.0
5.6
37.5
17.0
62.5
2.3
33.5
99.3
49.3
39.3
3.4
65.5
67.5
5008
22.0
27.5
22.5
80.5
1.5
67 ,0
2.8
45.8
26.3
55.0
48.3
90
Before
29.4
38.0
7.3
10.5
11.4
60.0
4.5
20.0
21.0
26.3
23.8
4.3
17.5
9.9
25.8
5.9
11.2
10.6
6.3
5.2
36.3
46.3
64.5
44.5
4.5
30.0
11.3
27.0
6.5
16.3
33.8
9.3
20.5
4.0
47.8
30.8
26.3
67.0
16.4
10.3
24.5
8.1
11.2
7.0
10.8
9.0
23.8
39.5
cm
After
31.8
33.5
3.0
9.8
2.3
77.0
2.8
25.0
18.3
17.5
42.8
4.5
26.3
34.3
24.5
2.4
15.8
11.8
31.3
2.5
41.8
55.8
64.8
50.8
4.8
25.8
11.3
57.8
4.0
44.3
49.5
54.5
16.3
2.5
57.8
40.8
55.8
42.0
25.5
27.0
37.0
3.5
35.0
3.9
45.5
13.5
45*5
30.8
120
Before
18.1
22.5
6.3
4.9
9.5
21.1
3.5
15.0
18.0
19.1
15.5
3.1
1.0
23.3
21.8
2.9
4.8
5.8
8.1
3.5
46.3
15.3
11.8
18.6
3.5
26.8
10.6
16.3
5.5
5.6
10.0
5.8
15.3
3.1
18.6
15.5
21.1
16.5
11.3
13.0
15.1
3.0
9.1
3.2
2.1
7.9
18.0
19.8
cm
After
12.6
26.9
37.3
3.4
22.3
44.5
2.5
26.4
27.4
8.4
28.8
10.4
20.0
11.9
30.0
1.4
1.6
17.4
22.3
8.3
29.5
27.0
28,8
9.5
10.0
13.8
11.9
21.0
1.3
10.4
4.1
.0
.0
2.4
24.8
13.3
28.5
27.4
35.8
23.1
27.8
2.8
14.1
1.3
34.5
10.1
17.5
23.3
T57
-------
Table B-23.
N-NO. in manure plots in 1973 from ceramic samplers at 106 cm
deptn. Manure application rates in mt/ha (dry weight).
6-30
7-17
Date
7-30 8-10
8-23
9-5
Manure Applied Only
Bare (0) A3
Bare (54) B3
Bare (108) C3
Bare (216) D3
Corn (0) A5
Corn (0) Bl
Corn (0) C4
Corn (0) C6
Corn (0) D2
Corn (54) A4
Corn (54) B2
Corn (54) B6
Corn (54) C5
Corn (54) Dl
Corn (108) Al
Corn (108) A6
Corn (108) B4
Corn (108) C2
Corn (108) D5
Corn (216) A2
Corn (216) B5
Corn (216) Cl
Corn (216) D4
Corn (216) D6
Bare (0) E3
Bare (54) F3
Bare (108) G3
Bare (216) H3
Corn (0) El
Corn (0) E5
Corn (0) F4
Corn (0) G5
Corn (0) H2
Corn (54) E6
Corn (54) F2
Corn (54) H4
Corn (54) G5
Corn (54) HI
Corn (108) E4
Corn (108) Fl
13
88
124
275
22
34
85
17
31
20
25
52
49
113
103
69
96
153
107
93
56
110
45
27
38
42
51
26
21
23
44
18
107
65
14
112
248
316
116
24
34
20
31
135
27
52
67
248
145
24
255
149
217
135
207
231
Manure
74
127
69
30
34
36
30
20
110
34
143
23
73
128
19
19
28
17
104
171
57
59
115
Applied
97
1
29
21
32
12
80
32
28
102
37
148
283
115
21
22
65
14
38
37
109
173
80
61
285
119
184
242
in Both
106
153
75
129
20
42
18
356
9
86
34
152
40
82
105
in 1972
37
181
223
137
21
17
76
19
41
104
15
32
86
133
163
88
71
285
50
163
102
208
229
1972 and
104
157
163
10
34
18
10
7
62
39
123
57
106
102
50
236
109
25
21
42
47
47
99
11
8
99
125
208
15
102
158
87
236
18
1973
115
194
209
7
17
17
19
4
7
23
81
66
52
84
148
-------
Table B-23.
N-NO in manure plots in 1973 from ceramic samplers at 106 cm
deptn". Manure application rates in rot/ha (dry weight)
(Continued).
(ppm)
Date
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
(108)
(108)
(108)
(216)
(216)
(216)
(216)
(216)
F6
G2
H5
E2
F5
Gl
G4
H6
6-30
116
70
76
138
121
111
54
7-17
181
110
173
262
124
44
7-30
___
164
233
85
8-10
178
144
429
152
60
8-23
163
125
124
253
241
128
63
9-5
37
166
134
298
64
157
9
Table B-24.
Electrical conductivity of samples withdrawn from ceramic
cups (106 cm depth) in manure plots in 1972. Manure appli-
cation rates in mt/ha (dry weight).
(mmho/cm)
Bare
Bare
Bare
Bare
Bare
Bare
Bare
Bare
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
(0)
(0)
(54)
(54)
(108)
(108)
(216)
(216)
(0)
(0)
(0)
(0)
(0)
(54)
(54)
(54)
(54)
(54)
A3
E3
B3
F3
C3
G3
D3
H3
A5
Bl
C4
C6
D2
A4
B2
B6
C5
Dl
7-14
2.9
4.5
3.6
2.4
.1
4.1
4.5
7-22
1.3
3.1
3.1
3.2
3.0
3.3
2.0
3.1
3.6
1.7
3.3
3.6
7-28
1.4
3.2
3.9
3.5
4.1
2
4.0
2.8
3.2
4.2
2.1
3.8
8-4
1.8
3.4
3.6
3.3
5
5.5
3.8
3.4
3.5
2.5
4.5
3.2
Date
8-10
2.6
4.3
4.7
4.3
4.4
18
4.7
3.0
3.9
4.7
2.9
4.5
4.5
8-19
2.5
4.7
4.7
4.1
4.7
12
5.8
4.4
3.3
4.2
3.7
4.1
2.9
4.6
4.6
8-23
2.2
4.5
5.2
4.4
4.5
47
6.3
4.9
3.8
4.1
4.0
4.4
3.0
5.2
4.1
4.7
4.6
9-7
2.0
4.3
4.9
4.3
4.3
71
6.1
5.0
3.6
3.9
4.4
2.6
4.7
4.6
4.4
9-18
2.5
4.7
5.1
4.3
4.5
84
5.5
5.3
3.5
4.1
3.8
5.0
3.1
4.9
4.1
4.1
4.7
149
-------
Table B-24.
Electrical conductivity of samples withdrawn from ceramic
cups (106 cm depth) in manure plots in 1972. Manure appli-
cation rates in mt/ha (dry weight) (Continued).
(mmho/cm)
7-14 7-22
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
Sudan
(108) Al
(108) A6
(108) B4
(108) C2
(108) C3
(108) D5
(216) A2
(216) B5
(216) Cl
(216) D4
(216) D6
(0) El
(0) E4
(0) Fl
(0) H2
(0) G6
(54)* E4
(54)* F6
(54)* G5
(54)* HI
(54)* H4
(108)* E4
(108)* F4
(108)* G2
(108)* H5
(108)* F5
(216)* E2
(216)* F2
(216)* Gl
(216)* G4
(216)* H3
2.7 2.
2.
3.
4.5 3.
2.0 2.
3.
2.
2
2.
4.
3.
3.1 3.
2
9
4
0
8
0
8
8
2
-
4
8
8
1.8
5.0 4.
2.8 3.
0
4.8 6.
3.
__ _ _
3.4 2.
0
0
5
7
-
6
5
_
4
9
-
7-28
4.1
4.2
4.1
3.6
4.3
3.3
4.9
3.9
2.0
4.0
4.5
5.4
_ __
3.7
3.9
8-4
2.5
4.2
4.2
4.8
5.5
4.8
3.9
4.5
3.2
4.6
3.9
4.9
5.4
3.8
Date
8-10
3.5
4.3
4.3
4.4
4.7
5.4
3.9
_
2.6
4.2
3.8
4.4
4.4
5.0
4.7
_
4.7
4.2
4.7
8-19
3.9
4.5
4.7
4.7
4.7
5.4
5.7
4.5
4.2
3.9
3.0
4.7
3.9
3.9
2.9
5.0
4.9
5.1
3.0
4.5
4.7
5.5
3.7
4.3
5.3
4.8
4.4
8-23
4.
4.
5.
6.
7.
4.
3.
4.
3.
3.
4.
4.
3.
5.
5.
5.
4.
4.
4.
5.
4.
4.
5.
5.
4.
-
8
5
4
7
1
-
8
8
3
8
9
1
3
0
0
2
0
3
1
1
1
1
6
3
1
9
9-7
3.9
4.3
5.3
4.7
3.9
4.2
5.6
4.6
__
4.3
4.1
5.4
5.0
9-18
4.6
4.5
5.8
7.5
7.4
5.3
4.6
3.8
4.6
4.1
4.6
4.1
5.1
5.6
5.0
4.6
4.3
5.8
5.8
4.7
4.7
4.7
5.5
5.2
150
-------
Table B-25.
Electrical conductivity of samples withdrawn from ceramic
cups (106 cm depth) in manure plots in 1973. Manure appli-
cation rates in mt/ha (dry weight).
(mmho/cm)
Bare (0) A3
Bare (54) B3
Bare (108) C3
Bare (216) D3
Corn (0) A5
Corn (0) Bl
Corn (0) C4
Corn (0) C6
Corn (0) D2
Corn (54) A4
Corn (54) B2
Corn (54) B6
Corn (54) C5
Corn (54) Dl
Corn (108) Al
Corn (108) A6
Corn (108) B4
Corn (108) C2
Corn (108) D5
Corn (216) A2
Corn (216) B5
Corn (216) Cl
Corn (216) D4
Corn (216) D6
Bare (0) E3
Bare (54) F3
Bare (108) G3
Bare (216) H3
Corn (0) El
Corn (0) E5
Corn (0) F4
Corn (0) G6
Corn (0) H2
Corn (54) E6
Corn (54) F2
6-30
Manure
1.2
3.4
3.7
5.4
3.3
2.3
3.7
3.7
2.2
4.2
3.2
2.7
3.7
3.7
4.2
4.1
4.5
5.2
4.8
5.1
Manure
3.7
4.4
4.1
4.9
3.2
2.9
3.1
3.8
3.8
2.0
2.8
7-17
applied
0.9
3.8
4.1
6.3
4.7
3.6
2.8
3.8
2.2
4.3
4.4
3.0
3.8
4.7
6.9
4.3
5.6
4.5
7.2
5.0
5.5
7.2
Date
7-30 8-10
only
0.9
3.1
3.6
3.8
4.2
6.4
4.0
4.3
5.0
in 1972
1.0
3.6
6.1
6.9
4.0
2.8
4.4
3.8
3.0
2.8
4.3
5.2
4.0
4.4
6.3
4.7
6.2
6.9
applied in both 1972
3.8
4.3
5.2
7.7
3.3
2.6
3.3
3.8
5.7
2.2
4.0
5.5
3.4
3.4
5.6
4.1
5.3
2.6
4.0
4.3
4.7
5.5
3.4
2.7
3.5
6.2
4.1
5.2
2.2
8-23
1.1
3.7
5.7
7.2
3.7
2.7
5.2
3.9
2.7
4.5
3.2
2.7
4.5
5.3
5.6
4.7
4.8
6.8
3.2
6.1
5.8
6.7
9.4
and
4.0
4.4
4.9
3.4
2.7
3.6
5.4
4.1
5.4
2.2
9-5
1.1
5.3
7.8
3.7
2.7
5.6
4.0
2.4
4.7
3.8
3.5
4.8
5.2
6.0
5.4
4.7
8.0
4.8
7.0
9.9
1973
3.9
4.8
5.3
5.8
3.3
2.8
3.3
6.3
4.1
4.7
* ^^
151
-------
Table B-25.
Electrical conductivity of samples withdrawn from ceramic
cups (106 cm depth) in manure plots in 1973. Manure appli-
cation rates in mt/ha (dry weight) (Continued).
(mmho/cm)
6-30
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
(54)
(54)
(54)
(108)
(108)
(108)
(108)
(108)
(216)
(216)
(216)
(216)
(216)
G5
HI
H4
E4
Fl
F6
G2
H5
E2
F5
Gl
G4
H6
7-17
Date
7-30 8-10
4.8
3.
6.
4.
6.
5.
3.
5.
4.
5.
4.
^
8
0
8
2
1
8
6
6
9
4
"
4.
4.
6.
7.
4.
5.
9.
5.
5.
-
3
_
4
2
0
_
3
5
6
5
2
~
4.3
_
4.8
6.0
8.8
4.3
__
5.
4.
4.
4.
6.
5.
6.
5.
5.
6
3
_
4
9
9
4
_
3
7
4
8-23
5.2
4.4
ll_
4.9
4.9
4.8
5.7
5.2
6.6
8.0
5.7
4.4
9-5
6.2
4.6
6.6
4.8
7.2
6.0
4.7
6.5
7.9
5.8
4.3
Table B-26.
N-N03 from the barrel lysimeters in 1972.
(ppm)
Treatment
Check (16)
Check (20)
Check (23)
440 kg/ha
440 kg/ha
440 kg/ha
440 kg/ha
440 kg/ha
110 kg/ha
110 kg/ha
110 kg/ha
110 kg/ha
^TR mf/Ko
ND
ND
N
N
N
N
N
N
N
wn
(1)
(4)
(6)
(7)
(9)
(5)
(8)
(10)
(11)
f>\
7-13
114
126
110
110
598
83
54
58
7-22
119
178
51
44
199
134
65
444
87
72
71
7-28
73
136
100
262
544
21
424
68
62
997
86
/. o
8-4
107
39
22
639
311
125
128
256
189
Date
8-10 8-18
86
112
99
620
226
270
371
86
145
134
130
1 77
67
107
86
231
588
256
353
121
62
108
128
i «;n
8-23
58
110
73
205
112
243
273
416
100
83
129
129
1 Q1
9-6
51
94
62
212
238
338
90
103
130
113
9-20
31
54
43
175
481
225
75
78
101
9^9
152
-------
Table B-26. N-NCU from the barrel lysimeters in 1972 (Continued).
(ppm)
Date
Treatment3 7-13 7-22 7-28 8-4 8-10 8-18 8-23 9-6 9-20
538 mt/ha
538 mt/ha
538 mt/ha
538 mt/ha
269 mt/ha
269 mt/ha
269 mt/ha
134 mt/ha
134 mt/ha
134 mt/ha
MD
M
M
M
M
M
M
M
M
M
(3)
(14)
(17)
(21)
(13)
(19)
(22)
(15)
(18)
(24)
.
24
112
7
75
«__
5
24
44
31
60
2
33
100
91
52
26
54
42
6
53
82
67
150
88
68
81
26
29
60
98
92
107
105
63
99
57
15
6
13
90
124
13
88
57
168
53
8
1
59
65
88
75
88
76
537
39
5
0
54
47
88
72
74
61
..__
30
0
1
39
48
74
58
70
56
234
1
1
17
28
51
38
34
44
is Ca(NO ) commercial fertilizer, M is manure and D is well
drained.
Table B-27. N-NO measured in the barrels in 1973.
(ppm)
Date
Treatment3 6-21 6-30 7-16 7-30 8-8 8-23 9-5
Checks
110 kg/ha
Ca(N03)2
16D
16
20D
20
23D
23
5D
5
8D
8
10D
10
11D
11
-
_
17
5
2
44
-
_
-
20
-
17
-
24
25
-
-
43
-
80
23
27
" ~"
11
_ - - -
~~ ~
1
~ ~ ~
_
1 0 - 1
65
^
-
153
-------
Table B-27. N-NO. measured in the barrels in 1973 (Continued).
(ppm)
Treatment3
440 kg/ha
Ca(N03)2
54 mt/ha
manual
108 mt/ha
manual
216 mt/ha
ID
1
4D
4
6D
6
7D
7
9D
9
12D
12
15D
15
18D
18
24D
24
13D
13
19D
19
22D
22
2D
2
3D
3
14D
14
21D
21
17D
17
6-21
-
-
-
68
-
225
-
425
-
178
-
-
18
-
2
7
-
3
-
_
336
-
248
257
1
-
0
-
2
6-30
-
-
-
45
54
214
-
396
-
215
-
9
-
19
7
-
0
-
6
376
-
294
234
1
-
0
-
0
7-16
1
-
200
-
170
0
38
-
224
23
-
-
11
1
-
-
0
-
189
-
264
-
-
-
-
Date
7-30
-
_
0
_
13
-
_
-
-
0
_
-
1
-
-
-
1
8-8 8-23
1
100
_ _
169
_
- -
0
- -
_ _
2
86
183
_ _
71
36
- -
28
9-5
-
0
_
_
_
_
_
_
-
_
-
-
-
_
-
-
-
_
-
27
-
refers to the water collected in the drains. Otherwise the samples
were collected from ceramic samples at about 70 cm depth. All treat-
ments were applied in 1972 only.
154
-------
Table B-28.
Electrical conductivity of water samples from the
barrel lysimeters in 1972.
(mmho/cm)
a
Treatment
Check (16)
Check (20)
Check (23)
440 kg/ha ND
440 kg/ha ND
440
440
440
110
110
110
110
538
538
538
538
538
269
269
269
134
134
134
kg /ha N
kg /ha N
kg /ha N
kg /ha N
kg/ha N
kg/ha N
kg/ha N
mt/ha MD
tat/ha MD
mt/ha M
mt/ha M
mt/ha M
mt/ha M
mt/ha M
mt/ha M
mt/ha M
mt/ha M
mt/ha M
(1)
(4)
(6)
(7)
(9)
(5)
(8)
(10)
(11)
(2)
(3)
(14)
(17)
(21)
(13)
(19)
(22)
(15)
(18)
(24)
7-13
2.8
4.0
3.2
4.6
6.7
2.9
3.1
5.5
__
3.1
^^~
3.1
2.6
3.1
7-22
2.5
2.2
2.6
3.0
3.2
4.6
2.6
4.7
3.2
4.2
3.5
2.9
2.5
2.7
2.5
2.4
2.6
2.3
4.6
2.6
2.7
7-28
2.4
3.3
2.9
5.1
4.2
3.3
5.2
2.9
3.3
4.6
4.4
3.5
2.3
2.7
3.1
3.3
2.5
2.9
2.9
2.7
3.0
3.0
8-4
3.2
4.2
3.0
6.3
5.4
4.2
4.6
5.9
5.8
5.4
3.2
5.0
3.9
4.9
4.5
5.9
4.0
3.9
Date
8-10
2.9
3.6
3.2
5.5
3.9
4.2
5.8
3.9
3.3
5.4
4.8
6.5
6.7
4.5
3.9
4.2
4.0
4.3
4.1
5.1
3.6
3.4
8-18
3.3
3.3
3.0
5.0
6.3
4.7
5.8
3.7
3.9
5.0
5»4
7.2
7.3
4.8
4.0
5.1
4.4
4.1
4.4
5.1
3.9
3.6
8-23
2.3
3.7
3.2
4.3
6.4
4.7
4.9
5.6
3.9
4.1
5.4
5.5
7.4
6.3
4.8
4.8
4.6
4.5
4.2
4.4
4.8
3.9
3.5
9-6
2.8
3.2
3.0
4.3
4.5
5.3
3.7
4.0
5.0
4.7
4.3
4f
.6
5.2
4.1
4.4
4.6
4.5
3.8
3.5
9-20
2.3
3.7
3.2
5.6
7.4
4.9
"
4.1
4.3
- ~
5.4
7.7
7f\
.2
41
.4
5.6
4.8
4.5
4.6
4.6
4.0
3.6
N is Ca(NO ) commercial fertilizer, M is manure, and D is well
drained.
155
-------
TECHNICAL REPORT DATA
{Please read Instructions on the reverse before completing)
REPORT NO.
EPA-660/2-75-005
3. RECIPIENT'S ACCESSION-NO.
TITLE AND SUBTITLE
fenagement Practices Affecting Quality and Quantity of
rrigation Return Flow
5. REPORT DATE
November 1974
6. PERFORMING ORGANIZATION CODE
AUTHOR(S)
Larry G. King and R. John Hanks
8. PERFORMING ORGANIZATION REPORT NO.
EPA-660/2-75-005
PERFORMING ORGANIZATION NAME AND ADDRESS
tah State University
Logan, Utah 84322
10. PROGRAM ELEMENT NO.
1BB039
11. CONTRACT/GRANT NO.
S801040
2. SPONSORING AGENCY NAME AND ADDRESS
Office of Research and Development
U.S. Environmental Protection Agency
Washington, D. C. 20460
13. TYPE OF REPORT AND PERIOD COVERED
Final (4-72 to 11-73)
14. SPONSORING AGENCY CODE
5.SUPPLEMENTARY NOTES
LABSTRACT
field and laboratory research was conducted to determine the effects of irrigation man-
agement and fertilizer use upon the quality and quantity of irrigation return flow.
The total seasonal discharge of salts from the tile drainage system was directly rela-
ted to the quantity of water discharged, because the solute concentration of the grounc
water was essentially constant over time. Under such conditions, reduction of salt
content of return flow is accomplished by reduced drain discharge. Irrigation manage-
ment for salinity control must be practiced on a major part of a particular hydrologic
unit so that benefits are not negated by practices in adjoining areas. Field studies
and computer models showed that salts may be stored in the zone above the water table
over periods of several years without adversely affecting crop yields on soils with
high"buffaring" capacity as encountered in this study. However, over the long term,
8alt balance must be obtained. Appreciable amounts of nitrate moved into drainage
water at depths of at least 106 cm from the applications of commercial fertilizer and
dairy manure to ground surface. Submergence of tile drains in the field reduced
nitrate concentrations in the effluent, especially under heavy manure applications.
This report was submitted in fulfillment of Grant No. S801040 by Utah State University
under the partial sponsorship of the Environmental Protection Agency. Work was
completed as of November 30, 1973.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COS AT I Field/Group
Irrigation return flow, *Drainage,
*Salinity, *Model studies, *Soil water
movement, *Nitrogen, Sprinkler irrigation
02/03
18. DISTRIBUTION STATEMENT
Selease unlimited
19. SECURITY CLASS (ThisReport)
21. NO. OF PAGES
20. SECURITY CLASS (Thispage)
22. PRICE
»A Form 2220-1 (9-73)
{, U. S. GOVERNMENT PRINTING OFFICE: 1975-698-2707122 REGION 10
------- |