EPA -660/2-74-033
April 1974
Environmental Protection Technology Series
Nitrogen and Phosphorus Losses
From Agronomy Plots
In North Alabama
Office of Research and Development
U.S. Environmental Protection Agency
Washington, D,C 20460
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PESEARCH KFPOKTING SERIES
Research reports of the Office of Research and
Monitoring*. Environmental Protection Aqency, have
been grouped into five series. These five bread
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 maxizmni interface in related
fields. The five series are:
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2, Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and non-point sources of
pollution. This work provides the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
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and policies of the Environmental Protection Agency, nor does
mention of trade names or commercial products constitute
endorsement or recommendation for use*
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EPA-660/2-74-033
April 1974
NITROGEN AND PHOSPHORUS LOSSES FROM
AGRONOMY PLOTS IN NORTH ALABAMA
By
Robert R. Bradford
Alabama A. & M. University
Normal, Alabama 35762
Grant No. 800401
Project 13020 DWH
Program Element 1BB039
Project Officer
Dr. George W. Bailey
Southeast Environmental Research Laboratory
Athens, Georgia 30601
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C 20460
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20*02 - Price 90 cents
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ABSTRACT
A study of nitrogen and phosphorus losses from Decatur silt loam soil
was conducted over three cropping periods from 1969-1972. Experimental
agronomy plots at Alabama A. & M. University were seeded to cotton,
corn, soybeans, and millet and compared with uncropped and unfertilized
check plots.
The effects of these crops on nitrogen losses total nitrogen, nitrate-
nitrogen, and ammonium-nitrogen (for 1971-1972 only) and phosphorus
losses were evaluated. Average total rainfall and losses of sediment
and runoff were also determined.
Losses of total nitrogen and nitrate-nitrogen were generally positively
correlated with the amounts of rainfall, runoff, and sediment. Phos-
phorus losses were positively correlated with sediment losses. More
than 95% of phosphorus losses were associated with sediment loss. Corn
was generally more effective in reducing total nitrogen and nitrate-
nitrogen losses via surface runoff than cotton; whereas nitrate-nitrogen
concentrations in subsurface water were lower in samples from cotton
plots. The effect of crops on loss of all nutrients was considerably
smaller than seasonal effects and sediment losses.
The effect of two fertilizers, ammonium nitrate and sulfur-coated urea
(a slow-release nitrogen fertilizer), upon nutrient losses showed no
evidence of superiority for sulfur-coated urea in reducing the total
nitrogen or nitrate-nitrogen losses.
This report was submitted in fulfillment of Project Number 13020 DWH,
Grant Number 800401, by the Department of Natural Resource and Environ-
mental Studies, Alabama Agricultural and Mechanical University, under
the (partial) sponsorship of the Environmental Protection Agency. Work
was completed as of December 1972.
ii
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CONTENTS
Page No.
Abstract ii
List of Figures iv
List of Tables v
Acknowledgments vii
Sections
I Conclusions 1
II Recommendations 2
III Introduction 3
IV Experimental Approach 4
V Results and Discussion 8
VI References 38
VII Glossary 40
ill.
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FIGURES
No, Page No.
1 Relationships between Rainfall, Runoff, and
Sediment during the 1969-1970 Season 9
2 Nitrogen Losses from Plots through Surface
Runoff during the 1969-1970 Season 15
3 Phosphorus Losses from Plots through Surface
Runoff during the 1969-70 Season 18
A Relationships between Rainfall, Runoff, and
Sediment during the 1970-1971 Season 21
5 Nitrogen Losses from Plots through Surface
Runoff during the 1970-1971 Season 26
6 Phosphorus Losses from Plots through Surface
Runoff during the 1970-1971 Season 28
7 Relationships between Rainfall, Runoff, and
Sediment during the 1971-1972 Season 30
8 Nitrogen Losses from Plots through Surface
Runoff during the 1971-1972 Season 34
9 Phosphorus Losses from Plots through Surface
Runoff during the 1971-1972 Season 37
iv
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TABLES
No. Page No.
1 Average Loss of Total Nitrogen through Surface
Runoff from Plots Seeded to Different Crops, 1969-1970 10
2 Average Concentration of Nitrate-Nitrogen in Surface
Runoff from Plots Seeded to Different Crops, 1969-1970 11
3 Average Loss of Nitrate-Nitrogen through Surface
Runoff from Plots Seeded to Different Crops, 1969-1970 12
4 Average Concentration of Nitrate-Nitrogen in Subsurface
Water from Plots Seeded to Different Crops, 1969-1970 13
5 Average Loss of Phosphorus through Surface Runoff from
Plots Seeded to Different Crops, 1969-1970 16
6 Average Loss of Total Phosphorus in Sediment Derived
From Plots Seeded to Different Crops, 1969-1970 17
7 Average Loss of Total Nitrogen through Surface Runoff
From Cotton and Corn Plots Treated with Sulfur-
Coated Urea and Ammonium Nitrate, 1970-1971 22
8 Average Loss of Nitrate-Nitrogen through Surface Runoff
From Cotton and Corn Plots Treated with Sulfur-
Coated Urea and Ammonium Nitrate, 1970-1971 23
9 Average Loss of Nitrate-Nitrogen through Surface
Runoff from Plots Seeded to Different Crops, 1970-1971 24
10 Average Loss of Total Nitrogen through Surface
Runoff from Plots Seeded to Different Crops, 1970-1971 25
11 Average Loss of Phosphorus through Surface Runoff from
Plots Seeded to Different Crops, 1970-1971 27
12 Loss of Total Nitrogen through Surface Runoff from
Corn and Millet Plots Treated with Sulfur-Coated
Urea and Ammonium Nitrate, 1971-1972 31
13 Loss of Nitrate-Nitrogen through Surface Runoff from
Corn and Millet Plots Treated with Sulfur-Coated
Urea and Ammonium Nitrate, 1971-1972 32
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TABLES (continued)
No. Page No.
14 Loss of Ammonium-Nitrogen through Surface Runoff from
Corn and Millet Plots Treated with Sulfur-Coated
Urea and Ammonium Nitrate, 1971-1972 33
15 Loss of Phosphorus through Surface Runoff from
Corn and Millet Plots Treated with Sulfur-Coated
Urea and Ammonium Nitrate, 1971-1972 35
vi
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ACKNOWLEDGMENTS
Dr. Robert R. Bradford was the principal investigator of this study.
Dr. Luke Mugwira was the associate investigator during the last year.
Mr. Leslie Glover, an undergraduate student in the Department of
Natural Resource and Environmental Studies, provided assistance in
field-related activities while Mr. V. J. Thakore and Mr. Donald Outland,
Research Assistants, assisted in the chemical and physical analyses of
samples.
Support of the project by the Office of Research and Development, Envi-
ronmental Protection Agency, and the cooperation of Dr. George W. Bailey,
Grant Project Officer, are gratefully acknowledged.
vii
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SECTION I
CONCLUSIONS
1. Average monthly losses of nitrate-nitrogen (N03-N) and soluble phos-
phorus (P) from small cotton, corn, millet, and soybean plots which
had been treated with fertilizers were approximately the same as
losses from uncropped and unfertilized check plots.
2. The concentration of NOj-N in subsurface water was higher than the
concentration observed in surface runoff; magnitudes of five-fold
were observed in some cases. This suggested that, for this soil,
more NOo-N may have been lost through infiltration and percolation
than via surface runoff *
3. Loss of nitrogen (N) as ammonium-nitrogen (NH^-N) in surface runoff
from the first two or three runoff producing rains following appli-
cation of fertilizers may constitute a more serious problem than
loss of NOo-N over the same interval. The surface losses of NO^-N
accounted for only 25% of the total N lost from the plots.
4. Sediment borne N and F constituted the greater loss of these two
nutrients. More than 95% of P was lost with the sediment.
5. The slow-release nitrogen used in this study showed no evidence of
being superior to ammonium-nitrate in reducing loss of N03~N or
total N. Losses of NH^-N from sulfur-coated urea (SCU) treated
plots were higher during the first three runoff producing rains than
from plots treated with ammonium-nitrate. This may have been accen-
tuated by the actual runoff of SCU pellets from the plots along with
surface water and sediment.
6. The type of crop grown may be a factor in loss of N.
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SECTION II
RECOMMENDATIONS
1. Growers should be encouraged to use management and tillage practices
which minimize erosion of croplands since the most serious losses of
N and P occurred as sediment contained in surface runoff.
2. Nitrogen and phosphorus requirements of major agronomic crops should
be established for the different geographical regions.
3. The optimum time to apply fertilizers to agronomic crops should be
determined. This is particularly needed where double cropping is
practiced since plant cover greatly influences loss of nitrogen
and phosphorus.
4. Growers should be encouraged to apply fertilizers at rates not in
excess of those recommended on the basis of soil test results.
5. Slow-release nitrogen fertilizers should be developed which release
N sufficient for adequate growth and nutrition of plants but which
reduce the need to apply large quantities of nitrogen. If such
fertilizers are in pellet form, care should be taken in the incorpo-
ration of such fertilizers into the soil.
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SECTION III
INTRODUCTION
There is considerable interest in the fate of nitrogen and phosphate
fertilizers applied to croplands. Some environmentalists believe
that nitrogen lost from fertilized fields through percolation and
surface runoff and phosphorus losses through surface runoff signifi-
cantly contribute to the eutrophication of waterways in the United
States and also reduce the quality of drinking water. The North
Alabama area of the Tennessee Valley has annual rainfall of about 140
cm which results in high amounts of runoff and erosion, and possible
loss of fertilizers from fields to which they are applied into rivers
and reservoirs.
Previous research data from different regions suggest that the amount
of nitrogen removed from croplands depends on the kind of nitrogen
fertilizer, crop, rainfall, and associated cultural practices.1»2,3
It has been found that phosphorus is lost through erosion essentially
as sediment-borne P, and very little is lost through leaching and
runoff water.5,6,7 There is, however, no general agreement on how
much nitrogen and phosphorus are contributed to water bodies by agri-
culture. Thus it has been suggested that the prolification of Milfoil
and algal blooms in several areas may be caused by changes in the nutri-
ent budget which created conditions ideal for growth of aquatic plants.
Some environmentalists believe that losses of nutrients from commer-
cial fertilizers applied to agricultural land play a significant
role in the increased instances of eutrophication.9 Others argue
that many water bodies naturally have enough NOg-N to support algal
blooms and that good plant cover reduces sediment loss from land
through runoff and thus enhances water quality.10
The objectives of this study were to:
1. Determine amounts of nitrogen and phosphorus in surface runoff
from Decatur silt clay loam soil under un-cropped and cropped
(cotton, corn, soybeans, and millet) conditions*
2. Compare nitrogen and phosphorus losses through surface runoff
from plots treated with a slow-release nitrogen source and a
conventional nitrogen source.
3
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SECTION IV
EXPERIMENTAL APPROACH
A field containing Decatur site play loam, which had not been cropped
for several years, was selected for use in this investigation. Two
adjacent sites with 1% and 6% slope, respectively, were graded to
uniform slope. Each site contained seven hydrocollection units (plots)
2.4 m x 4.6 m and were spaced 2.1 m apart in order to minimize fertili-
zer contamination. Each hydrocollection unit was marked by metal
frames 2.4-m wide, 4.6-m long, 0.5-m high, and imbedded into the soil
to a depth of 15 cm. Surface runoff from the plots was directed into
190-liter holding tanks through 15-cm diameter metal conduits installed
at ground level. The holding tanks were fitted with covers to prevent
unwanted precipitation from entering.
Suction lysimeters consisting of a plastic pipe, 5 cm in diameter,
capped on the lower end by a porous ceramic cup, and designed to per-
mit intake and removal of subsurface water were installed to a depth
of 1.2 m in the center of each plot. The.lysimeters were maintained
in an evacuated condition between sampling periods by means of a porta-
ble vacuum pump. Two rain gauges were located in the test area for
collecting data on natural rainfall. No supplementary irrigation was
used during the investigation. After each runoff producing rain repre-
sentative runoff samples were taken in duplicate from each holding tank.
These samples were stored at 0°C prior to chemical analysis.
1969-1970 CROPPING AND RUNOFF SEASON
Initial soil analyses were:
Total N In top 15 cm 9.1 kg/ha
Total P in top 15 cm 414 g/ha
Soluble P in subsurface water (1.2 m) 0.44 mg/1
During the first year of the study, losses of N and P in runoff and
percolating water were monitored from the plots cropped with 'Stone-
ville1 cotton, 'Pioneer 309B1 corn, and 'Hood1 soybeans. Each crop
-------
was planted in two plots. A check plot was left at each site and crops
were randomized within each site. Fertilizers for the following crops
were applied as NH,N03 and 0-20-20 broadcast and disked under at
the following (kg/ha) rates:
N P205 K20
Cotton ----------- 22 67 67
Corn --------------- 22 62 62
Soybeans ---------- 0 45 45
Because of the delayed funding of this proposal, the crops were planted
on August 12 which was late in the season for these crops in North
Alabama; therefore, no sidedressing with additional 67 kg/ha of N
was made as originally planned. The plants were harvested on October 15
and barley was planted on all plots to provide a winter cover crop.
Total nitrogen, which includes organic-nitrogen plus ammonium-nitrogen,
was determined in surface runoff by Kjeldahl method. Nitrate-nitrogen
and soluble phosphorus were determined in surface runoff and subsurface
samples by methods recommended by FWPCA.H Surface runoff and subsurface
water were filtered to remove sediment prior to analysis for nitrate-
nitrogen and soluble phosphorus.
Sediment content in surface runoff samples was determined by thoroughly
mixing one liter of surface runoff, then quickly decanting the homo-
geneous sample into a tared 100-ml beaker. The sample was then
brought to dryness on a steam plate and the beaker reweighed.12
Total phosphorus and organic phosphorus in sediments removed from sur-
face runoff were determined by procedures described in Methods of Soil
Analysis . Total nitrogen in sediments removed from surface runoff
was determined by the Kjeldahl method. Rainfall data were obtained via
two rain gauges located in the plot area.
Statistical tests employed to compare data collected were analysis of
variance, least significant difference (LSD), and simple correlation.
A preliminary analysis of variance of the data indicated that there
were no significant differences between the two sites for the para-
meters studied. Consequently, the two sites were treated as blocks
for the three cropping seasons (1969-1972).
1970-1971 CROPPING AND RUNOFF SEASON
The practices employed during the first year of the investigation were
repeated in 1970 and 1971 with some modifications. In the second year,
nitrogen losses were evaluated as a function of N fertilizer. Conven-
tional ammonium nitrate (AN) was compared with slow-release fertilizer,
sulfur-coated urea (SCU-D), supplied by the Tennessee Valley Authority.
-------
This experiment was intended to evaluate relative losses of N in run-
off as influenced by these two N fertilizers. Fertilizers for the
crops shown were applied at the following (kg/ha) rates:
N
Cotton
90 67 67
y u o i \* 2
0 45 45
The following chemical composition and dissolution rates were calcu
lated from weighted average values for this SCU blend:
Composition Dissolution rate, % N
Daily
Z N % S _ 7 days 7-14 days
29.6 30.8 9.0 0.3
The dissolution rates were measured in water at 38°C. Sulfur-coated
urea contained 3% sealant (wax) and 0.25% microbiocide (coal tar) over-
laid on a layer of sulfur. The same cotton, corn, and soybean varie-
ties used in the first year were planted on May 11. Barley was grown
on all plots as a winter cover crop.
Because of the very low concentrations found in 1969-1970 samples,
subsurface water was not analyzed for NO^-N and soluble P. Analytical
techniques for measuring N and P losses, statistical methods, and
meteorological procedures were the same as those used in 1969-1970
season*
1971-1972 CROPPING AND RUNOFF SEASON
Data for 1970-1971 showed no significant difference in N loss between
the three row-crops grown; therefore, in 1971-1972 cotton and soybeans
were replaced by a forage crop, namely millet. It was thought that
because of the tillered growth characteristics of millet, it might sub-
stantially differ from corn which is a typical representative of row
crops. Plots were rototilled and fertilized on April 3rd. Millet and
corn were planted on May 16.
Efforts were made to quantify N and F losses during ten runoff producing
rain periods from April 1971 through March 1972. Surface runoff samples
from the plots were analyzed for NIfy-N in addition to the analyses indi-
cated for the 1969-1970 season. Collection of rainfall data and statis-
tical tests used were the same as described for the first year of the
study.
6
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Crops grown, replications, fertilizers (application methods were
the same as for the 1969-1970 season) and their rates for the
1971-1972 season are shown below:
Crop
Corn
Corn
Millet
Millet
Fallow
Replications
3
3
3
3
2
N Source N
NH4N03 100
SCU 100
NH4N03 100
SCU 100
00
Kg/ha
P205
35
35
35
35
00
K20
35
35
35
35
00
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SECTION V
RESULTS AND DISCUSSION
1969-1970 CROPPING AND RUNOFF SEASON
Results
Rainfall data (cm/mo) on plot area during the 1969-1970 season are
given below:
Sept.
11.15
Oct.
6.32
Nov.
6.30
Dec.
22.71
Jan.
6.02
Feb.
7.34
Mar.
14.96
Apr.
23.06
The average total monthly rainfall, surface runoff, and sediment losses
for the 1969-1970 cropping and runoff season are shown in Figure 1.
Rainfall was high in September, December, March, and April and was
uniformly lower during the rest of the season. The average monthly
runoff and sediment losses followed distribution patterns similar to
those observed for rainfall (Fig. 1).
Nitrogen Losses
The average monthly total nitrogen loss, the concentration and total
loss of NOq-N in surface runoff, and the concentration of NOq-N in
subsurface water are shown in Tables 1, 2, 3, and 4, respectively. All
of these forms of nitrogen were significantly affected by the type of
crop and the time (month) of the season. The total N loss in the sea-
son increased only where cotton was planted (Table 1). The average
N03-N concentration in surface runoff was significantly higher in plots
planted to cotton, corn, and soybeans than in runoff from check plots
(Table 2). When averaged over the 8-month sampling period, total
N03-N losses through surface runoff from plots planted to cotton
were lower than losses from corn and soybean plots (Table 3).
However, the concentration of N03~N in the subsurface water was higher
only on corn plots (Table 4).
8
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60 i
50
o
LU
CO
40
o
n
30
o
to
20
10
0
RAINFALL (cm)
RUNOFF (liters/ha) XlO'l
SEDIMENT (kg/ha) X2X1Q-2
*
A
*
\\
» m *
* I \ * *
* I \
> / \ *
« / \
/ \
I * '
* I \ * *
: / \ : :
: ' \ ' * *
: / \ ' 'V
// \\ ///
V V\.>7
A--«
-* .»'**-**,.
A ' -A.
A-
I
I
I
1
x/
/
*
I
SEPT. OCT. NOV. DEC.
JAN.
FEB. MAR. APR.
Figure 1. Relationships between rainfall, runoff, and sediment during
the 1969-1970 season.
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Table 1. AVERAGE LOSS OF TOTAL NITROGEN THROUGH SURFACE RUNOFF FROM
PLOTS SEEDED TO DIFFERENT CROPS
(kg/ha)
1969-1970
Month
Sept.
Oct.
Nov.
Dec.
Jan.
Feb.
Mar.
Apr.
Means
Cotton
10.8
9.5
9.0
24.6
9.0
8.4
15.8
24.6
14.0
Corn
8.4
6.3
6.2
18.5
7.3
6.7
14.0
19.7
10.9
Crops
Soybeans
10.1
6.7
6.7
21.3
6.7
6.2
15.7
16.9
11.3
Check
9.1
6.2
5.6
20.7
5.6
5.6
13.4
17.9
10.5
Means
9.6
7.2
6.9
21.3
7.2
6.7
14.8
19.8
LSD at 0.05 for comparing means: F ratio
Crops 1.2 8'9S2
Months 1.7 68.1
*, ** Significant at the 5% and 1% level of probability, respectively,
10
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Table 2. AVERAGE CONCENTRATION OF NITRATE-NITROGEN IN SURFACE RUNOFF
FROM PLOTS SEEDED TO DIFFERENT CROPS
(fflg/1)
1969-70
Month
Sept.
Oct.
Nov.
Dec.
Jan.
Feb.
Mar.
Apr.
Means
LSD at 0.05
Crops
Months
Crops
Cotton
0.17
0.11
0.10
0.23
0.17
0.20
0.23
0.19
0.17
for comparing
Corn
0.22
0.10
0.09
0.24
0.18
0.22
0.25
0.20
0.19
means :
Soybeans
0.20
0.15
0.13
0.33
0.12
0.16
0.25
0.17
0.19
0.03
0.04
Check
0.17
0.07
0.12
0.18
0.11
0.14
0.18
0.16
0.14
F ratio
A *|
7^*
Means
0.19
0.11
0.11
0.24
0.14
0.18
0.22
0.18
* Significant at the 5% level of probability,
11
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Table 3. AVERAGE LOSS OF NITRATE-NITROGEN THROUGH SURFACE RUNOFF
FROM PLOTS SEEDED TO DIFFERENT CROPS
(g/ha)
1969-1970
Month
Sept.
Oct.
Nov.
Dec.
Jan.
Feb.
Mar.
Apr.
Means
LSD at 0.05
Crops
»* .«_*_
Crops
Cotton
4.48
4.48
3.47
11.76
5.71
2.80
26.32
33.15
11.52
for comparing
Corn
7.28
4.03
3.92
15.23
7.39
4.03
31.92
34.83
13.58
means:
Soybeans
5.71
7.84
6.27
17.47
6.16
3.47
32.48
31.36
13.85
F
1.86
n £.* 1 1
Check
5.15
3.36
5.60
11.31
4.48
2.80
24.08
28.56
10.67
ratio
7.U*
to o **
Means
5.65
4.93
4.82
13.94
5.94
3.28
28.70
31.98
*, ** Significant at the 5% and 1% level of probability, respectively.
12
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Table 4. AVERAGE CONCENTRATION OF NITRATE-NITROGEN IN SUBSURFACE WATER
FROM PLOTS SEEDED TO DIFFERENT CROPS
(mg/D
1969-1970
Month
Sept.
Oct.
Nov.
Dec.
Jan.
Feb.
Mar.
Apr.
Means
Crops
Cotton
0.92
0.25
0.23
0.90
1.03
1.08
1.17
1.07
0.83
LSD at 0.05 for comparing
Crops
Months
*, ** Significant at the
Corn
1.16
0.24
0.22
1.15
1.15
1.10
1.11
1.17
0.91
means:
5% and 1%
Soybeans Check
0.92
0.22
0.21
0.91
0.98
0.97
1.05
0.93
0.77
0.06
0.09
level of
0.96
0.20
0.17
0.95
0.91
1.05
1.07
1.00
0.79
F ratio
4 -4
78.3
probability,
Means
0.99
0.23
0.20
0.98
1.02
1.05
1.10
1.04
respectively.
13
-------
Losses of total N and NO^-N and the Nt^-N concentrations were generally
positively correlated with the amounts of rainfall, runoff, and sedi-
ment loss. The highest levels of each of the six parameters occurred
during the months of December, March, and April and also in Septem-
ber in the case of N03-N concentration (Figs. 1 and 2). The following
data also indicate that the N and P losses were significantly corre-
lated with the amount of runoff and sediment losses. Correlation
coefficient (r) relating surface runoff and sediment loss to nitrogen
and phosphorus (P) levels is given below:
Surface runoff Sediment
Sediment loss .707**
Total N03-N .948** .733**
Total N .619** .913**
Soluble P .724** .437*
The concentration of N03~N in subsurface water was five times higher
than in surface runoff and remained approximately 1 ppm during the
growing season except for the low values in October and November
(Table 4).
Phosphorus Losses
The data in Table 5 indicate that the losses of soluble P through run-
off and percolation were not Influenced by the type of crop grown.
Although the level of soluble P in surface runoff did not change during
the sampling period, total loss of soluble P by runoff and the con-
centration of the P in subsurface water changed between different
months (Table 5). Total soluble P in surface runoff was higher in
March than in other months. Total soluble P in surface runoff, sedi-
ment P, and organic P in sediment loss were generally correlated with
rainfall and runoff (Figs. 1 and 3). Comparison of data in Tables
5 and 6 indicate that nearly all P losses from the plots were due to
sediment loss. Organic P losses accounted for approximately 30 to 40%
of the total P lost from the plots.
Concentration of P in subsurface water was quite variable and was not
significantly affected by the crop. These P levels were higher from
September to December than from January to April. The concentrations
of P in surface runoff and in subsurface water are within the range
reported by Duley1^ who found P contents of 0.12 to 1.50 ppm in surface
runoff water collected from a set of unfertilized erosion plots receiv-
ing natural rainfall.
14
-------
40
Ul
UJ
30
20
10
60 h
- "TOTAL N (kg/ha)
^Nof-N (g/ha)
50
X10'z
..._...
\\
*-
*
*
I I 1 I I I I _ _ I
SEPT. OCT. NOV. DEC. JAN. FEB. MAR. APR.
Figure 2. Nitrogen losses from plots through surface runoff during
the 1969-1970 season.
15
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Table 5. AVERAGE LOSS OF PHOSPHORUS THROUGH SURFACE RUNOFF FROM PLOTS
SEEDED TO DIFFERENT CROPS
(g/ha)
1969-1970
Month
Sept.
Oct.
Nov.
Dec.
Jan.
Feb.
Mar.
Apr.
Means
LSD at 0.05
Crops
Months
Crops
Cotton
5.4
6.0
5.4
10.5
8.0
2.4
18.1
8.4
8.0
for comparing
Corn
5.6
10.2
9.0
11,3
9.1
3.9
18.8
14.0
10.2
means:
Soybeans
4.3
4.1
9.5
11.3
8.5
2.8
15.8
18.0
9.3
3.6
Check
4.4
9.6
8.3
4.5
6.9
1.3
9.9
11.0
6.9
F ratio
NS
11.1*
Means
4.9
7.5
8.1
9.4
8.1
2.6
15.7
12.7
* Significant at 5% level of probability
NS Non-significant
16
-------
Table 6. AVERAGE LOSS OF TOTAL PHOSPHORUS IN SEDIMENT DERIVED
FROM PLOTS SEEDED TO DIFFERENT CROPS
(kg/ha)
1969-1970
Month
Sept.
Oct.
Nov.
Dec.
Jan.
Feb.
Mar.
Apr.
Means
LSD at 0.05
Crops
Months
Crops
Cotton
12.3
11.2
11.2
61.6
11.2
6.7
29.1
90.7
29.3
for comparing
Corn
11.2
6.7
6.7
39.7
6.7
6.7
22.4
50.4
18.8
means :
Soybeans
12.3
6.7
11.2
45.9
11.2
6.7
29.1
50.4
21.7
11.87
Check
16.8
11.2
11.2
45.9
11.2
5.6
28.0
40.3
21.3
F ratio
NS
24.62**
Means
13.2
8.9
10.0
48.2
10.0
6.4
27.1
57.9
NS Non-significant
** Significant at the 1% level of probability
17
-------
60
50
40
to
LU
£ \l
20
10
SOLUBLE P (g/ha)
^RUNOFF P (kg/ha) XIO3
SEDIMENT P (kg/ha)
I
;*
'i ^
i!\
:: *
:\
J I \ I i
SEPT. OCT. NOV. DEC. JAN. FEB. MAR. APR.
Figure 3. Phosphorus losses from plots through surface runoff during
1969-1970 season.
18
-------
Discussion
To determine nitrogen losses from surface runoff in 1969-1970, data
were collected for total N and N03-N. Of these, N03~N losses were
only a small percent (generally less than 1%) of the total.
Total N losses were invariably associated with high rainfall months
as exemplified by the high values in December, March, and April. Rain-
fall was the single most important factor affecting N losses through
surface runoffs and its impact can be seen on cropped and fertilized
as well as on check plots (Table 1).
Contribution of nitrate from farmland to the ground water is of inter-
est in terms of causing contamination of drinking water. For the
1969-1970 season, N03-N losses in subsurface water were not correlated
with rainfall (Table 4). The data for this period indicated that
cotton because of its growth habit, elaborate root structure, and long-
er growing season was more efficient than corn in reducing loss of
N03-N in subsurface water. In general, these losses were approximately
at the level of 1 ppm (Table 4). Although this concentration of
nitrate in the subsurface water exceeded 0.03 ppm N03~N level that
would cause eutrophication,-^ it is doubtful that these losses signifi-
cantly affect water quality. Additional dilution of such concentra-
tion in ground water should also be considered when interpreting such
data.
Phosphorus Losses
Our data confirms earlier findings that a very large amount of P is lost
with the sediment; only 1% or less P leaves the cropland in soluble formr
The concentration of P lost can generally be estimated by multiplying
the total sediment lost by the total P content of sediment which, in
this study, was found to be 0.5%. The type of crop did not affect
soluble P loss. Since soluble P is in equilibrium with sediment P and
it is in greater magnitude, practices which would reduce erosion would
contribute considerably toward reducing loss of total P from cropland.
1970-1971 CROPPING AND RUNOFF SEASON
Results
Rainfall data (cm/mo) on plot area during the 1970-1971 season are
given below:
May
7.34
June
6.60
July
6.02
Aug.
7.29
Sept.
5.08
Oct.
10
.74
Nov.
6
.60
Dec.
5
.26
Jan.
8.38
19
-------
The average total monthly rainfall, runoff, and sediment losses from
the experimental plots during the 1970-1971 season are shown in
Figure 4. The highest monthly rainfall occurred in October, followed
by May and January, with monthly precipitation varying between 5.08 cm
and 6.60 cm during the rest of the season. Monthly runoff and sediment
generally followed a similar pattern as rainfall.
The data were analyzed initially to compare N loss for the two differ-
ent fertilizer materials, sulfur-coated urea and ammonium nitrate. A
second analysis was done to compare N and P losses among corn, cotton,
soybeans, and check plots.
Nitrogen Losses
The results for total N losses and losses of N03-N through surface run-
off from plots that received AN and SCU are given in Tables 7 and 8.
Neither fertilizer source showed evidence of being superior to the other
in reducing losses of N03-N or total N via surface runoff during the
1970-1971 season. The fluctuation of average monthly concentrations
of N03-N in surface runoff generally followed those of average monthly
rainfall and runoff.
Data for comparing the effects of cotton, corn, and soybeans on N
losses are shown in Tables 9 and 10. The total N loss and total losses
of N03-N are not significantly affected by the type of crop. Differ-
ences in concentrations and total losses of NOg-N during the season
were apparently a result of fluctuations in surface runoff. Compari-
son of the data in Tables 7 and 8 indicate that N03~N accounted for
only 4% of the total N loss from the plots. The nitrogen losses from
plots via surface runoff during 1970-1971 season are shown in Figure 5.
Phosphorus Losses
It was assumed that SCU and AN would probably not influence P losses
from plots and no statistical tests were made to compare the effects
of the two fertilizers on P losses. Table 11 shows P losses as func-
tions of the type of crop and month during the 1970-1971 season. The
average total P content in sediment was approximately 0.5%. Consider-
ing the amounts of sediment in the runoff from plots (Fig. 4), it is
evident that most of the P losses were due to sediment losses. The
data in Figures 4 and 6 show that total P in surface runoff was closely
associated with sediment loss throughout the 1970-1971 season.
Discussion
Nitrogen and phosphorus losses from plots were not affected by growing
cotton, corn, or soybeans nor by SCU and AN applications equivalent
to 90 kg/ha of N on cotton and corn plots. These losses were generally
increased by high rainfall and were correlated with runoff and sediment
20
-------
£
Ul
1-4
a
UJ
in
a
3~
U-
u.
0
C£
m
_J
j£
i
ll-
CS
to
L_
J~
0
^
100
90
80
70
60
50
40
30
20
10
n
mm
- "RAINFALL (cm) /
ARUNOFF (liters/ha) /
.......... SEDIMENT fka/ha} /
*
- / :
/ s
A.-/--A \
- t . :
/ / M
*f *
/ / . t \
\ // \\
* / /
/ > A
\\ ' / \\ '
A / / » /
» / * *
\\ * : \: /
*. \ ^ / »: /
\ \ S ! V:
\ X .x / V: /
* v / 5 -
*. » /
^ A * * »
" ^ * **
* - i / «*
^.,.--""ii^-.-'- ^ .__j(/l--
i " ii i.* i ,
JUNE
JULY AUG. OCT.
NOV.
DEC.
JAN.
Figure 4. Relationships between rainfall, runoff, and sediment during
the 1970-1971 season.
21
-------
Table 7. AVERAGE LOSS OF TOTAL NITROGEN THROUGH SURFACE RUNOFF FROM
COTTON AND CORN PLOTS TREATED WITH SULFUR-COATED UREA
AND AMMONIUM NITRATE
(g/ha)
1970-1971
Month
June
July
Aug.
Oct.
Nov.
Dec.
Jan.
Means
LSD at 0.05
Crops
Fertilizer
Months
Corn
SCU
172
199
228
146
142
22
216
161
for comparing
Sources
AN
61
189
197
130
243
24
177
146
means:
Cotton
SCU
202
187
23
292
292
19
239
179
AN
116
260
47
249
682
25
209
227
F ratio
NS
NS
NS
Means
138
209
124
204
340
22
210
NS Non-significant
22
-------
Table 8. AVERAGE LOSS OF NITRATE-NITROGEN THROUGH SURFACE RUNOFF FROM
COTTON AND CORN PLOTS TREATED WITH SULFUR-COATED UREA AND AMMONIUM NITRATE
(g/ha)
1970-1971
Month
June
July
Aug.
Oct.
Nov.
Dec.
Jan.
Means
Grand Means
LSD at 0.05 for
Crops
Fertilizer
Months
Corn
SCU
8.1
1.0
8.8
3.0
8.1
0.4
3.0
4.6
5.
comparing
sources
Cotton
AN
6.0
4.2
7.6
2.9
21.3
0.4
1.9
6.3
5
means:
SCU
16.4
2.4
3.2
24.5
8.9
0.3
4.5
8.6
5.5
AN
6.8
2.4
2.0
4.6
25.3
1.8
9.0
7.4
8.0
F ratio
NS
NS
6.7*
Means
9.3
2.5
5.4
8.7
15.9
0.7
4.6
NS Non-significant
* Significant at the 5% level of probability.
23
-------
Table 9. AVERAGE LOSS OF NITRATE-NITROGEN THROUGH SURFACE RUNOFF
FROM PLOTS SEEDED TO DIFFERENT CROPS
(g/ha)
1970-1971
Month
June
July
Aug.
Oct.
Nov.
Dec.
Jan.
Means
LSD at 0
Crops
Months
Crops
Cotton Corn
11.6
2.4
2.6
14.5
17.1
1.0
6.8
8.0
.05 for
7.1
2.6
8.2
3.0
15.7
0.4
2.4
5.5
comparing means:
Soybeans
17.9
5.1
9.6
5.6
10.0
2.3
5.8
8.1
F
5.5 5.
Check
12.2
4.4
6.5
1.6
4.8
0.6
3.0
4.7
ratio
NS
6**
Means
12.2
3.7
6.7
6.2
11.7
1.1
4.5
NS Non-significant
** Significant at the 1% level of probability
24
-------
Table 10. AVERAGE LOSS OF TOTAL NITROGEN THROUGH SURFACE RUNOFF
FROM PLOTS SEEDED TO DIFFERENT CROPS
(g/ha)
1970-1971
Month
June
July
Aug.
Oct.
Nov.
Dec.
Jan.
Means
LSD at 0.05
Crops
Crops
Cotton
158
224
35
270
487
22
224
203
for comparing
Corn
116
194
213
137
193
23
196
153
means :
Soybeans
114
373
138
121
161
46
203
165
F
i -i c e
Check
193
202
96
170
345
40
159
172
ratio
NS
..**
Means
146
248
120
175
296
33
196
Months
NS Non-significant
** Significant at the 1% level of probability
25
-------
UJ
100
90
80
70
60
50
40
30
20
10 I
0
TOTAL N (kg/ha) X10'1 FERTILIZERS AND CROPS
N03-N (mg/1) X10? FERTILIZERS^ CROPS*
N03-N (g/ha) FERTILIZERS? AND CROPS6
:\
r^\
\\
\\
JUNE JULY AUG. OCT. NOV. DEC.
JAN.
Figure 5. Nitrogen losses from plots through surface runoff during
the 1970-1971 season.
26
-------
Table 11. AVERAGE LOSS OF PHOSPHORUS THROUGH SURFACE RUNOFF FROM PLOTS
SEEDED TO DIFFERENT CROPS
(g/ha)
1970-1971
Month
June
July
Aug.
Oct.
Nov.
Dec.
Jan.
Means
LSD at 0.05
Crops
Months
Crops
Cotton
4.5
1.2
0.4
5.4
18.9
0.5
2.5
4.8
for comparing
Corn
5.6
1.8
3.8
4.3
7.8
0.4
2.4
3.7
means:
Soybeans
4.3
1.0
1.0
1.2
4.0
0.8
1.3
1.9
3.9
Check
1.0
0.3
0.5
0.8
6.0
0.3
0.8
1.4
F ratio
NS
4.4**
Means
3.8
1.0
1.4
2.9
9.2
0.5
1.8
NS Non-significant
** Significant at the 1% level of probability
27
-------
Ul
cc
SOLUBLE P (mg/1) XI0 IN RUNOFF
ATOTAL P (g/ha) IN RUNOFF
SEDIMENT P (g/ha) X10-2
A
; \
I
I \
JUNE JULY
Figure 6. Phosphorus losses from plots through surface runoff during
the 1970-1971 season.
28
-------
loss suggesting that the seasonal conditions were more important con-
siderations in controlling N and P losses from fields than were crop
type and fertilizer forms.
Phosphorus data supported findings of the first cropping year which
indicated that practically all P losses from the plots were associated
with sediment.
1971-1972 CROPPING AND RUNOFF SEASON
Results
Rainfall data (cm/runoff producing rain) on plot area during the
1971-1972 season are given below:
Apr.
4/6
July
7/16
Aug.
8/6
Dec.
12/3
Dec.
12/11
Dec.
12/27
Jan.
1/3
Jan.
1/18
Feb.
2/1
Mar.
3/17
8.36 11.94 7.54 5.72 11.44 6.55 8.46 8.28 6.55 12.55
For 1971-1972 the data (surface and sediment runoffs, rainfall, total
N, P, etc.) were prescribed for each runoff producing rain period rather
than averaged over a month as was done in 1969-1970 and in 1970-1971.
The average total rainfall, runoff, and sediment losses from the plots
during 10 runoff producing periods for the 1971-1972 season are given
in Figure 7. Runoff did not follow a similar distribution pattern to
that of rainfall during most of the runoff producing rains. The lack
of correlation between rainfall and runoff may have been due to varia-
ble rainfall intensity during the intervals between runoff periods.
Nitrogen Losses
When compared with check plots, growing corn and millet did not reduce
nitrogen losses from the plots (Tables 12, 13, and 14). However, total
N and nitrate-nitrogen losses were significantly affected by AN, SCU,
and by time of sampling during the season. The losses of N over the
1971-1972 cropping and runoff season were higher for SCU and AN treated
plots than for check plots. Total N losses occurring in the first four
runoff producing periods accounted for 50 to 70% of all N losses moni-
tored- (Fig. 8). Losses of N during the remaining 1971-1972 season were
relatively uniform. However, Nfy-N losses were approximately five times
those observed for NOo-N. Computations from data in Tables 12 and 14
indicate that Nfy-N loss accounted for about 20% of total N losses
through runoff.
Phosphorus Losses
Total loss of P in 1971-1972 season are shown in Table 15. Corn and
millet did not affect P losses from plots when compared with check plots.
29
-------
100
90
....
|80
O
UJ
"» 70
o
«£
u! 60
u_
o
S 50
m
_l
_l
i 40
»t
g
fe 30
H-
I 20
"*
10
n
"RAINFALL (cm)
_= A RUNOFF ( 1 i ters/ha )
.......... SEDIMENT fka/ha) X1Q~2
A
/\
/ \
\A ^ A. A
/ % V
/ \
» \ ^
* ^
\ 'A \ *A
V \ /
- x\ \/
^
^
\
\
*
^^'"*>.^ \ ^^^ -8-«.r-« X'7^1
1 I I T 1 1 1 I" 1 1
23456
RUNOFF PERIOD
8
10
Figure 7. Relationships between rainfall, runoff, and sediment during
the 1971-1972 season.
30
-------
Table 12. LOSS OF TOTAL NITROGEN THROUGH SURFACE RUNOFF FROM CORN AND
MILLET PLOTS TREATED WITH SULFUR-COATED UREA AND AMMONIUM NITRATE
(g/ha)
1971-1972
Runoff date
Apr. 6
July 16
Aug. 6
Dec. 3
Dec. 11
Dec. 27
Jan. 3
Jan. 18
Feb. 1
Mar. 17
Means
SCU
963
471
394
233
152
125
107
239
234
180
310
Grand Means
Corn
AN
883
536
646
416
441
260
142
171
312
325
413
329
Millet
SCU
1045
653
660
335
138
132
80
276
299
284
390
304
AN
542
475
264
170
143
128
89
242
273
262
259
LSD at 0.05 for comparing means:
Crops
Fertilizers 52
Runoffs 94
Crop x fertilizer x runoff interaction 208
NS Non-significant
** Significant at the 1% level of probability
Check
418
405
461
359
158
165
142
153
166
204
263
F ratio
NS
7.2**
34.9**
NS
Means
770-2
508.0
485.0
302.6
206.4
162.0
112.0
216.2
256.8
251.0
31
-------
Table 13. LOSS OF NITRATE-NITROGEN THROUGH SURFACE RUNOFF FROM CORN AND
MILLET PLOTS TREATED WITH SULFUR-COATED UREA AND AMMONIUM NITRATE
(g/ha)
1971-1972
Runoff date
Apr. 6
July 16
Aug. 6
Dec. 3
Dec. 11
Dec. 27
Jan. 3
Jan. 18
Feb. 1
Mar. 17
Means
Corn
SCU
36.0
6.4
15.7
37.5
6.6
5.5
1.7
3.0
2.3
8.3
12.3
AN
43.0
5.2
5.9
6.9
4.5
9.6
2.6
2.1
1.9
5.2
8.7
Grand means 7.8
LSD at 0.05 for comparing means
Crops
Fertilizers
Runoffs
Crox x fertilizer x runoff
Millet
SCU
47.5
18.3
19.9
46.6
17.3
13.8
7.7
13.7
2.0
14.7
20.1
10.
interaction
AN
19.8
3.6
3.9
24.5
10.3
6.1
2.0
2.0
1.5
4.5
7.8
1
3.2
5.9
14.1
Check
2.6
1.4
2.6
2.7
2.0
2.7
1.8
1.8
1.3
5.5
2.4
F ratio
NS
40.2**
14.7**
NS
Means
29.78
6.98
9.60
23.64
8.14
7.54
3.16
4.52
1.80
7.64
NS Non-significant
** Significant at the 1% level of probability
32
-------
Table 14. LOSS OF AMMONIUM-NITROGEN THROUGH SURFACE RUNOFF FROM CORN
AND MILLET PLOTS TREATED WITH SULFUR-COATED UREA AND AMMONIUM NITRATE
(g/ha)
1971-1972
Runoff date
Apr. 6
July 16
Aug. 6
Dec. 3
Dec. 11
Dec. 27
Jan. 3
Jan. 18
Feb.l
Mar. 17
Means
Corn
SCU
184
98
108
39
21
28
30
22
22
28
58
AN
224
96
95
90
55
84
57
25
35
27
79
Grand means 55
Millet
SCU
233
110
122
65
25
42
27
27
30
31
71
50
LSD at 0.05 for comparing means:
Crops
Fertilizers
Crops x fertilizer interaction
Crop x fertilizer x runoff interaction
AN
61
52
53
73
30
56
40
17
22
27
43
14.9
21.0
31.0
Check
31
24
28
25
11
48
40
22
28
35
29
F ratio
NS
15.0**
6.3*
4.4*
Means
146.6
76.0
81.2
58.4
28.4
51.6
38.8
22.6
27.4
29.6
NS Non-significant
** Significant at the 1% level of probability
33
-------
CO
I
LU
LU
"J
LU
l_^
LU
oe
100
90
80
70
60
50
40
30
20
10
n *
-TOTAL N (g/ha) X 0.1 tv
_ *N03-N (mg/1) X 0.01 /\
»N03-N (g/ha) X 0.1 / \
iNH4-N (g/ha) X 2 | \
I I
I \
! \
! \ *
i \ /
' \ /
N / * /
V t^ 1 *
\ X Xx / \ / *
\ ^ ^, / \ / /
A .1 1 * !
>t \ / 1 / /
X^v ^ / V /
>w \ /
\^ /
y... ' \ \ 1 0 *
\ ^»* *»,! \ ,* *% ;
\ X* \*^** ****«. '****
\* """^ * * "^« - ^^^C.'*
*
t*^ + t--t t f f---i^-^--x>
456
RUNOFF PERIOD
8
10
Figure 8. Nitrogen losses from plots through surface runoff during
the 1971-1972 season.
34
-------
Table 15. LOSS OF PHOSPHORUS THROUGH SURFACE RUNOFF FROM CORN AND
MILLET PLOTS TREATED WITH SULFUR-COATED UREA AND AMMONIUM NITRATE
(g/ha)
1971-1972
Runoff date
Apr. 6
July 16
Aug. 6
Dec. 3
Dec. 11
Dec. 27
Jan. 3
Jan. 18
Feb. 1
Mar. 17
Means
scu
53.5
46.8
52.2
18.1
15.1
12.2
18.3
41.3
36.3
37.3
33.1
Grand means
Corn
AN
120.7
98.1
109.7
12.7
15.5
26.9
17.0
27.4
43.6
46.9
51.9
40.0
Millet
SCU
98.3
66.8
44.2
11.5
14.3
63.8
14.0
47.7
49.7
59.0
46.9
LSD at 0.05 for comparing means:
Crops
Fertilizers
TJiinnff «
AN
68.3
62.5
41.1
15.9
12.0
17.9
15.4
47.1
33.5
45.8
36.0
43.9
9.7
17.8
Check
2.1
7.2
9.5
7.2
3.9
7.5
11.6
5.7
9.2
9.8
7.4
F ratio
NS
37.5**
7.1**
Means
68.58
56.28
51.34
13.08
12.16
25.66
15.26
33.84
34.46
39.76
NS Non-significant
** Significant at the 1% level of probability
35
-------
The P levels in runoff were highest in the first three runoff periods
and lover during the fourth, fifth, sixth, and seventh periods (Fig. 9).
The P losses in runoff in 1971-1972 were not as closely related to
sediment loss as in the 1969-1971 period.
Discussion
The application of 100 kg/ha N as SCU and AN increased N losses from
plots cropped with corn and millet during April to December 1971,
especially where SCU was applied. Data from samples taken April 6th
reflect high values for nutrient loss since the plots had been rototilled
and fertilized on April 3rd Just prior to a runoff producing rain. In
the first four runoff producing periods, the lighter weight and larger
pelleted SCU may have washed with the runoff resulting in an inflated
value of total N loss from such plots when compared with AN.
The results obtained in this study suggest that for annual corps, SCU
is not superior to AN in controlling N and P losses through surface
runoff. Cropping practices employed for growing millet and corn appar-
ently had no effect on N and P losses.
36
-------
CO
LU
LU
a.
LU
>
LU
ce
100
on
j\j
80
70
60
50
40
30
20
10
_
- "SOLUBLE P (mg/1) X102
ARUNOFF P (g/ha)
?m T MCMT D ^ L- n / 1\ -% \
g/ ;
-
-
T
^ /
- /
*» .
/
/
* r
m
* . ^r ^*J
ff_ * * T*« ^^ *
.-^A *AV.-C«-^*A , * A ****...
. f i i T ' v -r T ?- i i
123456 7 89 10
RUNOFF PERIOD
Figure 9. Phosphorus losses from plots through surface runoff during
1971-1972 season.
37
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SECTION VI
REFERENCES
1. Moe, P. G., J. V. Mannering, and C. B. Johnson. Loss of Fertili-
zer in Surface Runoff Water. Soil Science. 104(6):205:211, 1967.
2. Moe, P. G., J. V. Mannering, and C. B. Johnson. A Comparison of
Nitrogen Losses from Urea and Ammonium Nitrate in Surface Runoff
Water. Soil Science. 105(6):168-174, 1968.
3. Timmons, D. R., R. E. Burnell, and R. F. Bolt. Loss of Crop
Nutrients through Runoff. Minn. Plant Sci. 24:16-18.
4. Viets, F. G., Jr. Fertilizer Use in Relation to Surface and
Ground Water Pollution. In: Fertilizer Technology and Use, Olsen,
R. A., et. al. (ed.) Madison, Wis. Amer. Soc. Agron. 1971.
5. Barrows, H. L., and V. J. Kilmer. Plant Nutrient Losses from Soils
by Water Erosion. Advances in Agronomy. 15:303-316. Academic
Press, Inc., New York. 1963.
6. Wadleigh, C. H. Agriculture and the Quality of Our Environment.
U.S. Dept. Agri. Misc. Publ. 1065. 1968.
7. Biggar, J. W. and R. B. Corey. Nitrate and Phosphate in Lakes
and Streams. Unpublished Mimeo. Madison, Wis. Univ. of Wisconsin.
8. Martin, J. B., Jr., B. N. Bradford, and H. G. Kennedy. Factors
Affecting the Growth of Najas in Pickwick Reservoir. TVA Rpt. No.
F70-74C02. 1969.
9. Edmondson, W. T. Fresh Water Pollution. In: Environment Re-
sources, Pollution and Society, Murdock, W. W. (ed.) 1972.
p 213-229.
10. Martin, W, P., W. E. Fenster, and L. D. Hanson. Fertilizer Manage-
ment for Pollution Control. Iowa State Univ. (Symposium: Role
of Agriculture in Clean Water. Ames. November 18-20, 1969.)
11. FWPCA Methods for Chemical Analysis of Water and Wastes. U.S. Dept.
of the Interior, Division of Water Quality Research. Cincinnati,
Ohio. 1969.
38
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12. Jackson, M. L. Soil Chemical Analysis. Prentice Hall, Inc. 1958,
13. Black, C. A., D. D. Evans, L. E. Ensminger, J. L. White, F. E.
Clark, and R. C. Dinauer. Methods of Soil Analysis. Amer. Soc.
Agron., Amer. Soc. for Testing and Materials. 1965.
14. Duley, F. L. The Loss of Soluble Salts in Runoff Water. Soil
Science. 21:401-409. 1926.
39
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SECTION VII
GLOSSARY
AN ATinnoTiiuTn-nitrate
N Nitrogen
NH/-N Ammonium-nitrogen
NOj-N Nitrate-nitrogen
P Phosphorus
SCU Sulfur-coated urea (slow-release nitrogen fertilizer)
Total Nitrogen Organic nitrogen plus ammonium nitrogen
Average monthly losses Sum of concentrations, volumes, or quantities,
measured for each runoff producing rain during a given month divided by
the total number of runoff producing rains for the month.
Check Plots Those plots which were uncropped and unfertilized.
Infiltration Movement of water from the surface into the soil.
Non-treated Plots Plots to which no fertilizers were applied.
Percolation - Movement of water through the soil.
Surface Runoff The water fraction of surface runoff after sediment
has been removed from water.
40 4US. GOVERNMENT PRINTING OFFICE: 1974 546-J18/382 1-3
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
. 1. Report No.
3, Accession No.
w
4. Title
NITROGEN AND PHOSPHORUS LOSSES FROM AGRONOMY PLOTS
IN NORTH ALABAMA
Authorfs)
Robert R. Bradford
3/15/74
8. f. * Tforath^ Organization
Report No.
9, Organization
Alabama A. & M. University
Normal, Alabama 35762
10. Project No.
13020DWH
11. Contract/Grant No.
800401
n. s; "
*foa
ProtectloB.
1.3 Type.. £ Repo * * #af
- Period Coveted
1969-1972
IS. Supplementary Notes
Environmental Protection Agency report
number, EPA-660/2-74-033, April 1974.
16. Abstract . .':..".,
A study of nitrogen and phosphorus losses from Decatur silt loam soil was conducted over
three cropping periods from 1969-1972. Experimental agronomy plots at Alabama A. & M.
University were seeded to cotton, corn, soybeans, and millet and compared with uncropped
and unfertilized check plots. .
The effects of these crops on nitrogen losses total nitrogen, nitrate-nitrogen, and
ammonium^nitrogen (for 1971-1972 only) and phosphorus losses were evaluated. Average
total rainfall and losses of sediment and runoff were also determined.
Losses of total nitrogen and nitrate-nitrogen were generally positively correlated with
the amounts of rainfall, runoff, and sediment. Phosphorus losses were positively corre-
lated with sediment losses. More than 95% of phosphorus losses were associated with
sediment loss. The effect of crops on loss of all nutrients was considerably smaller
than seasonal effects and sediment losses.
The effect of two fertilizers, ammonium nitrate and sulfur-coated urea,upon nutrient
losses showed no evidence of superiority for sulfur-coated urea in reducing the total
nitrogen or nitrate-nitrogen losses.
I7a. Descriptors Rater qualtly, Water pollution agricultural sources, Nitrogen -
Phosphorus losses. Cropping effects, Seasonal effects, Fertilizer effects, Sediment
losses, Cultural practices.
17b. Identifiers
Nutrient loss reduction, North Alabama Decatur silt loam, Seasonal-Cropplng-Fertilizer
Effects, Water quality Sediment loss Interaction.
17c. COWRR Field & Group
18. Availability
Abstractor Robert R.
! 19. Securitv C/gis.
;"'.. (Repoi.)
'JO. Se> 'rity Cf, ss.
(Page)
M. No. of
Pages
:2. Privet '
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
US DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C. 2O24O
JJra/Jfjpr4 1 institution Alabama A. & M. University
VV R S! C i O a
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