RANGELAND WATERSHED WATER BUDGET AND GRAZING CATTLE NUTRIEN1
CYCLING
UoSo Enviroranentail Protection Agency
Ada. Oklahoma
P»iTO 0F ElilKi
mS.
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'EPA-600/2-83-017
March 1983
RANGELAND WATERSHED WATER BUDGET
AND GRAZING CATTLE WASTE
NUTRIENT CYCLING
by
Jeff Powell, Frank R. Crow
and Donald G. Wagner
Oklahoma Agricultural Experiment Station
Stillwater, Oklahoma 74078
R-803735
Project Officer
Lynn R. Shuyler
Animal Production Section
R. S. Kerr Environmental Research Laboratory
Ada, Oklahoma 74820
R. S. KERR ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
ADA, OKLAHOMA 74820
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-83-017
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Rangeland Watershed Water Budget and Grazing Cattle
Waste Nutrient Cycling
5. REPORT DATE
March 1983
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Jeff Powell, Frank R. Crow and Donald G. Wagner
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Oklahoma Agricultural Experiment Station
Stillwater, Oklahoma 74078
10. PROGRAM ELEMENT NO.
APBC
11. CONTRACT/GRANT NO.
R-803735
12. SPONSORING AGENCY NAME AND ADpRESS
U.S. Environmental Protection Agency
Robert S. Kerr Environmental Research Laboratory
P.O. Box 1198
Ada, OK 74820
13. TYPE OF REPORT AND PERIOD COVERED
Final '
14. SPONSORING AGENCY CODE
EPA/600/15
15. SUPPLEMENTARY NOTES
16. ABSTRACT .
This research project was designed to determine baseline data concerning the
source, movement, concentration and factors affecting nonpoint pollutants in runoff
from a representative 60-hectare, tallgrass prairie watershed grazed by cattle in
North Central Oklahoma. Measurements were made to determine precipitation and runoff
amounts and concentrations of sediment, nitrogen, phosphorus, potassium, BOD, COD and
TOG. Concentrations of N, P, K, Ca and structural carbohydrates were determined in
live and standing dead vegetation and dung collected periodically from different
locations on the watershed. Stocking density and grazing pressure were calculated.
Independent site factors were used in regression equations to predict plant species
abundance, live and standing dead vegetation biomass, utilization and dung pat density
and biomass.
The amount of nonpoint source pollution contributed to receiving waters by runoff
from the watershed was comparable to that from tallgrass prairie watersheds in other
parts of the United States and was minimal when compared to other nonpoint sources of
pollution. Significant runoff occurred in every season, but spring was the season
with the greatest potential runoff and potential pollution because precipitation and
soil water content were greatest and ground cover was lowest at this time. Sediment
was the most significant pollutant. Direct overland movement of dung into stream
channels was minimal because standing vegetation and ground litter.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
t>.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Agricultural Wastes
Animal Husbandry
Waste Disposal
Animal Waste Management
Rangelands
Pastures
Nonpoint Sources
Runoff
43F
68D
18. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
332
(This page)
22. PRICE
EPA Form 2220-1 (9-73)
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DISCLAIMER
Although the research described in this article has. been funded wholly or
in part by the United States; Environmental Protection Agency through contract
or grant R-80373S to Oklahoma State University, it has not been subjected to
the Agency's required peer and policy review and therefore does not necessarily
reflect the views of the Agency, and no official endorsement should be inferred.
11
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FOREWORD
EPA is charged by Congress to protect the Nation's land, air and water
systems. Under a mandate of national environmental laws focused on air and
water quality, solid waste management and the control of toxic substances,
pesticides, noise, and radiation, the Agency strives to formulate and imple-
ment actions which lead to a compatible balance between human activities and
the ability of natural systems to support.and nurture life. In partial
response to these mandates, the Robert S. Kerr Environmental Research Lab-
oratory, Ada, Oklahoma, is charged with the mission to manage research
programs to investigate the nature, transport, fate, and management of
pollutants in ground water and to develop and demonstrate technologies for
treating wastewaters with soils and other natural systems; for controlling
pollution from irrigated crop and animal production agricultural activities;
for controlling pollution from petroleum refining and petrochemical indus-
tries; and for managing pollution resulting from combinations of industrial/
industrial and industrial/municipal wastewaters.
This project was initiated to evaluate the effects of livestock
pasturing in the tallgrass prairie regions of the United States on the
quality of nonpoint surface runoff. The pasturing regime, more commonly
practiced in the tallgrass prairie, was evaluated to determine the potential
contribution to nonpoint source pollution. This information is useful in
determining optimal practices which will lead to the development of Best
Management Practices (BMPs).
Clinton W. Hall, Director
Robert S. Kerr Environmental
Research Laboratory
111
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CONTENTS
Foreword iii
Abstract vi
Figures vii
Tables xii
Acknowledgements xvi
1. Introduction 1
2. Conclusions 3
3. Recommendations 5
4. Study Area 6
Location 6
Climate 8
Physiography 10
Access roads 13
Vegetation 16
Land use 16
5. Methods, Materials and Facilities 18
Weather 18
Runoff measurement 19
Water sample collection 24
Water sample handling and analyses 25
Soils 25
Soil water 25
Vegetation and ground cover 27
Site factor effects on vegetation 29
Herbage utilization by livestock 35
Dung deposition and degradation 37
6. Results and Discussion 39
Weather 39
Water * 41
Precipitation and runoff 41
Monthly summary of rainfall and runoff 41
Sediment and nutrient sampling and analyses 53
Hydrographs 60
Soils 60
Soil depth and texture 60
Soil chemical composition 70
Soil water 72
Seasonal trends 72
Effect of grazing 75
Soil water use rates 78
Vegetation 81
Plant biomass 81
IV
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Peak production 83
Range sites 88
Grazing effects 90
Site factors, species frequency and biomass 94
Species frequency (late winter, 1976) 94
Site factor regression equations (1976-78) ... 109
Livestock grazing 112
Utilization 115
Yearlong 115
Grazing period 121
Effect of site factors 126
Plant chemical composition and digestibility 130
Seasonal variation 130
Annual variation 135
Chemical interrelationships 143
Chemical yield (biomass X content) 143
Dung biomass, density and degradation 150
Literature Cited 167
Appendices
A. Soil descriptions for watershed soils 173
B. Discharge equations and rating tables for the main
runoff measuring weir 189
C. Summary of water analyses procedures 190
D. Daily meteoroligical and runoff data |194
E. Sediment and nutrient analysis data for runoff from
hydrologic events in 1977, 1978 and 1979 239
F. Computation of sediment lost by runoff from hydrologic
events in 1977, 1978 and 1979 251
G. Soil profile descriptions of sampling locations ........ 262
H. Average (21 sampling dates) soil water content
(%, X±SE) for sampling locations 284
I. Sampling date, precipitation insoak, soil water content
change and soil water use_rate per period 289
J. Average (N=25) plant biomass (X±SE; kg/ha, oven-dry)
components on tall grass prairie watershed grazed
by cattle in North Central Oklahoma, 1976-78 294
K. List of plant species found on tall grass prairie
watershed grazed by cattle in North Central I
Oklahoma, 1976-78 ;295
L. Average (N=25) chemical composition (%, X±SE) in
. aboyeground vegetation components on a tallgrass
prairie watershed grazed by cattle in North
Central Oklahoma, 1976-78 301
M. Average (N=25) chemical yield (kg/ha, X±SE) in aboveground
vegetation components on a tallgrass prairie watershed
grazed by cattle in North Central Oklahoma, 1976-78 ... 311
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ABSTRACT
This research project was designed to determine baseline data concerning
the source, movement, concentration and factors affecting nonpoint pollutants
in runoff from a representative tallgrass prairie watershed grazed by cattle
in North Central Oklahoma. A 60-hectare, tallgrass prairie watershed, moder-
ately grazed yearlong by beef cows and calves was instrumented to determine
precipitation and runoff amounts and concentrations of sediment, nitrogen,
phosphorus, potassium, BOD, COD and TOC. Soil types, range sites and topo-
graphy were surveyed, mapped and described. Soil water content, live and
standing dead vegetation biomass, dung pat density, ground cover and herbage
utilization were determined at 29 locations on the watershed periodically
from April 76 through October 78.
Concentrations of N, P, K, Ca and structural carbohydrates were deter-
mined in live and standing dead vegetation and dung collected periodically
from different locations on the watershed. Stocking density and grazing pres-
sure were calculated. Independent site factors were used in regression equa-
tions to predict plant species abundance, live and standing dead vegetation
biomass, utilization and dung pat density and biomass. Changes in dung chem-
ical composition over time were determined for dung deposited during different
seasons and in place for different periods of time.
The amount of nonpoint source pollution contributed to receiving waters
by runoff from the watershed was comparable to that from tallgrass prairie
watersheds in other parts of the United States and was minimal when compared
to other nonpoint sources of pollution, such as cropland and fertilized pas-
tures. Significant runoff occurred in every season, but spring was the sea-
son with the greatest potential runoff and potential pollution because pre-
cipitation and soil water content were greatest and ground cover was lowest
at this time. Sediment was the most significant pollutant and was contri-
buted by watershed areas with no ground cover, such as cattle trails leading
into drainageways and the sides of drainageway channels. Direct overland
movement of dung into stream channels was minimal because standing vegetation
and ground litter on the lower slope positions acted as a filter.
Plant transpiration rapidly depleted soil water between mid May and mid
July, especially in the upper 35-cm of the soil profile. This drawdown re-
duced the probability of runoff from all precipitation events except intense
Jthunderstorms during the summer~and~"fal 1. Tallgrasses, standing vegetation
and ground cover were much greater on loamy prairie range sites on lower
slope positions, whereas dung density and biomass were greater on the upland,
more xeric, shallow prairie sites. Areas selected by cattle for bedgrounds
and resting areas had a much greater influence on dung distribution than did
areas selected for grazing. Nutrient concentrations in dung decreased to a
steady state level in less than six months in any season of deposition.
vi
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FIGURES
Number Page
1. Environmental research watershed location and vicinity map . . 7
2. Longterm (1893-1980) climate for Stillwater, Oklahoma .... 9
3. Average monthly absolute maximum and absolute minimum
temperatures (C), Stillwater, Oklahoma 9
4. Climograph of average monthly temperature and average monthly
precipitation for Stillwater, Oklahoma, 1893-1980 10
5. Aerial view of environmental research watershed, Noble
County, Oklahoma 11
6. Topographic map of experimental research watershed in North
Central Oklahoma 12
7. Soils map of experimental watershed in North Central Oklahoma. 15
The description of each soil is in Appendix A.
8. View of grassland aspect of experimental watershed in North
Central Oklahoma 17
9. View of woody" vegetation along drainageways in the experi-
mental watershed in North Central Oklahoma 17
10. Recording rain gage 18
11. Site location of main weir 20
12. View of V-notch of watershed main weir 21
13. Plan and elevation drawing of main weir 22
14. Downstream side of watershed main weir 23
15. Watershed pond weir 23
16. Head gage (left) and runoff sampler (right) 24
17. Equipment used to determine soil water content 26
vii
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Number Page
18. Recording neutron counts for soil water determination .... 27
19. Schematic used to randomly select plot locations at each site. 28
20. Determining vegetation and ground cover 28
21. Nylon bags used to determine dry matter digestibility .... 30
22. Inserting nylon bag set through canula 30
23. Retrieving nylon bags after 48-hour digestion period 31
24. Nylon bags with digestion residue before washing 31
25. Location of 20 transects used to determine species frequency
in relation to slope position, aspect and soil types ... 32
26. Collecting ground litter from one of three quadrats per
transect 33
27. Collecting A-horizon soil core for soil water and chemical
composition determination 34
28. One of three exclosures constructed on watershed 36
29. One of 75 movable cages used to determine herbage utilization
by grazing cattle 36
30. Collecting dung pat to determine change in chemical composi-
tion after a known period of time after deposition .... 37
31. Weekly absolute maximum and absolute minimum temperatures (C)
during study period 40
32. Precipitation and runoff for 10-day periods during study
period 42
33. Number of weeks per precipitation class during study period. . 43
34. Hydrograph for event of May 20-21, 1977 61
35. Hydrograph for event of May 23, 1977 61
36. Hydrograph for event of May 27, 1977 62
37. Hydrograph for event of Nov. 14, 1978 62
38. Hydrograph for event of March 18, 1979 63
Vlll
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Number Page
39. Hydrograph for event of March 22, 1979 63
40. Hydrograph for event of April 10, 1979 64
41. Hydrograph for event of May 2, 1979 64
42. Hydrograph for event of June 9, 1979 65
43. Hydrograph for event of July 17, 1979 65
44. Variation of BOD, COD, and TOC with runoff from event of May
20, 1977 66
45. Variation of COD and TOC with runoff from event of June 5,
1978 66
46. Soil profile showing soil depth, horizon thickness and
texture of the 29 sampling locations. Soil profiles for
the ungrazed (U) locations inside exclosures and
adjacent grazed (6) locations are also shown 67
47. Total soil water content (mm) for watershed based on average
of 29 locations or regression equation using seven
representative locations 74
48. Average soil water content (mm) in upper 35-cm and lower 35-
to 120-cm sections of watershed soil 76
49. Change in soil water content (%) at different depths over time
in relation to precipitation and runoff 77
50. Average soil water content (%, X±SE) for four ungrazed and
four adjacent, grazed locations on a tall grass prairie
watershed in North Central Oklahoma. Average of data from
21 collection dates between June 1976 and December 1978 . . 79
51. Soil water use rate (mm/day) in relation to precipitation
insoak (mm) 80
52. Average (X±SE) GROUND LITTER, STANDING DEAD and LIVE
herbaceous vegetation (kg/ha, oven-dry) on a tall grass
prairie watershed grazed by cattle in North Central
Oklahoma 82
53. Dry matter production (kg/ha, oven-dry) of herbaceous species
classes during the 1976 growing season on a tallgrass prairie
watershed grazed by cattle in North Central Oklahoma ... 84
IX
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Number Page
54. Dry matter production (kg/ha, oven-dry) of herbaceous species
classes during the 1977 growing season on a tall grass prairie
watershed grazed by cattle in North Central Oklahoma ... 85
55. Dry matter production (kg/ha, oven-dry) of herbaceous species
classes during the 1978 growing season on a tallgrass prairie
watershed grazed by cattle in North Central Oklahoma ... 86
56. Average LIVE and STANDING DEAD plant biomass (kg/ha, oven-dry)
inside (ungrazed) and outside (grazed) three, 0.5-ha
exclosures on a tallgrass prairie watershed grazed by
cattle in North Central Oklahoma 91
57. Effect on browsing on shrubs outside exclosure 93
58. Average STANDING, GROUND, and TOTAL LITTER phytomass (kg/ha,
oven-dry) on the three slope positions. LSD n,
(STANDING) = 210 kg/ha; LSD n, (GROUND) = 200uKg/ha;
LSD Q5 (TOTAL) = 360 kg/ha :. 96
59. Frequency (%) of species classes by aspect, February 1976 . . 98
60. Frequency (%) of dominant species in relation to slope
position and grazing pressure, February 1976 102
61. Frequency (%) of lower successional species in relation to
slope position and grazing pressure, February 1976 . . . .103
62. STANDING DEAD and GROUND LITTER biomass (kg/ha) in relation
to slope position and grazing pressure, February 1976 . . .105
63. 'Chemical composition (%) of STANDING DEAD and GROUND LITTER
in relation to slope position and grazing pressure,
February 1976 108
64. Stocking density (animal units/ha) during the study period . .114
65. Grazing pressure (animal units/1000 kg herbage) during the
study period 116
66. Average monthly Kjelflahl nitrogen content (%) of plant materials
and dung during the April 1976 - March 1977 period.
(Between-months probabilty levels or LSD nf- were LSD n_ =
0.0155K, PO.19, LSD n, = 0.29%, P<0.17 and P<0.10 f5?
LIVE, dung, GROUND tHTER and STANDING DEAD, respectively). 131
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Number Page
67. Average monthly phosphorus content (%) of plant materials
and dung during the April 1976 - March 1977 period.
(Between-months probability levels or LSD nl- were
LSD n, = 0.01555, P<0.10, P<0.09 and LSD'«? = 0.010%
for'CIVE, dung, GROUND LITTER and STANDINGUDEAD,
respectively.) 132
68. Average monthly potassium content (%) of plant materials and
dung during the April 1976 - March 1977 period. (Between-
months probability levels or LSD ni- were LSD nt. = 0.17%,
P<0.27, LSD n, = 0.025% and LSD'£1=0.064% f6r\IVE,
dung, GROUND-LITTER and STANDING'DEAD, respectively.) ... 133
69. Average monthly calcium content (%) of plant materials and
dung during the April 1976 - March 1977 period. (Between-
months probability levels or LSD n(. were P 0.12, LSD
0.17%, P<0.14 and LSD n, = O.OSiTfor LIVE, dung, GROt
LITTER and STANDING DEAD, respectively.) 134
70. Dung biomass (kg/ha) distribution on a tallgrass prairie
watershed grazed by cattle in North Central Oklahoma . . . 155
71. Accumulative dung pat density (number/ha) after 1 April 77
on a tallgrass prairie watershed grazed by cattle in
North Central Oklahoma. Those values followed by the
same letter are not statistically different at the 0.05
level of significance 156
72. Average (7 grazing periods) utilization (%) of LIVE and
STANDING DEAD herbage by sampling location on a tall grass
prairie watershed grazed by cattle in North Central
Oklahoma, 1976-78 161
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TABLES
Number Page
1. Drainage Network Characteristics 13
2. Monthly Rainfall and Runoff Amounts, Environmental and Hydrology
Research Watersheds, Oklahoma State University 44
3. Summary of Rainfall and Runoff Events (April 1976 - December
1979), Environmental Research Watershed, Oklahoma State
University . 46
4. Annual Maximum Runoff Event for 1977, Environmental Research
Watershed, Oklahoma State University 47
5. Annual Maximum Runoff Event for 1978, Environmental Research
Watershed, Oklahoma State University ... 48
6. Annual Maximum Runoff Event for 1979, Environmental Research
Watershed, Oklahoma State University . 49
7. NWS Precipitation Intensity Frequency Table for Stillwater,
Oklahoma . 51
8. Precipitation Intensity and Return Period for Annual Maximum
Runoff Events, Environmental Research Watershed, Oklahoma
State University 51
9. Annual Maximum Discharges and Annual Maximum Volumes of Runoff
for Selected Time Intervals, Environmental and Hydrology
Research Watersheds, Oklahoma State University 52
10.^ Sampling Frequency for Sediments and Nutrients 53
11. Summary of Sediment Loss by Runoff, Environmental Research
Watershed, Oklahoma State University 54
12. Summary of Nitrogen Loss by Runoff, Environmental Research
Watershed, Oklahoma State University 56
13. Summary of Phosphorus and Potassium Loss by Runoff, Environ-
mental Research Watershed, Oklahoma State University ... 58
XI1
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Number Page
14. Summary of BOD, COD, and TOC Loss by Runoff, Environmental
Research Watershed, Oklahoma State University 59
15. Average Chemical Composition of A Horizon of Soils at 29
Permanent Sampling Locations 71
16. Chemical Composition (X±sd) of Soils A Horizon of Soils at
Different Slope Positions on Grazed, Tallgrass Prairie
Watershed in North Central Oklahoma, March 1977 72
17. A Horizon, Soil Factors (X"±C.V. [%]) on a North Central
Oklahoma Rangeland Watershed Grazed by Cattle, 1976 .... 73
18. Plant Species Class Biomass (kg/ha), Composition (%) and
Selected Site Factors on Loamy and Shallow Prairie Range
Sites on a Tallgrass Prairie Watershed Grazed by Cattle
in North Central Oklahoma, 1976-78 89
19. Comparison of Average (3 Paired Samples) Plant Species Class
Biomass (kg/ha, Oven-Dry), Composition (%) and Selected
Other Factors Inside (Ungrazed) and Outside (Grazed) Three,
0.5-ha Exclosures on a Tallgrass Prairie Watershed Grazed
by Cattle in North Central Oklahoma, 1976-78 92
20. Frequency of Occurrence (%) for Selected Species and Species
Classes on Different Slope Positions . . 95
21. Frequency of Occurrence (%) for Selected Species and Species
Classes on Different Soil Types 100
22. Regression Equations for Plant Biomass Response Variables
Using Site Factors on 25 Locations on a Tallgrass Prairie
Watershed Grazed by Cattle in North Central Oklahoma
1976-78 110
23. Regression Equations for Selected Ground Cover Response Vari-
ables Using Site Factors on 25 Locations on a Tallgrass
Prairie Watershed Grazed by Cattle in North Central
Oklahoma, 1976-78 113
24. Average Yearlong (7 Utilization Periods; 25 Paired Samples/
Period) Caged and Grazed Herbaceous Species Class Biomass
and Utilization Factors on a Tallgrass Prairie Watershed
Grazed by Cattle in North Central Oklahoma, 1976-78 .... 117
Xlll
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Number Page
25. Average Grazing Period (25 Paired Samples/Grazing Period)
Biomass (kg/ha, Oven-Dry) and Selected Site Factor Differ-
ences Between Caged (Ungrazed) and Grazed Sampling
Locations on a Tallgrass Prairie Watershed Grazed by Cattle
in North Central Oklahoma, 1976-78 122
26. Regression Equations for Vegetation Utilization (%) Using Site
Factors on 25 Locations on a Tallgrass Prairie Watershed
Grazed by Cattle in North Central Oklahoma, 1976-78 .... 127
27. Average (25 Samples/Day) Chemical Composition (%) of LIVE
Vegetation on a Tallgrass Prairie Watershed Grazed by
Cattle in North Central Oklahoma, 1976-78 136
28. Rank Order by Sampling Date and Nitrogen (N), Phosphorus (P),
Potassium (K) and Calcium (CA) Contents (%) in STANDING
DEAD Vegetation on a Tall grass Prairie Watershed Grazed
by Cattle in North Central Oklahoma, 1976-78 139
29. Rank Order by Sampling Date and Ash, Acid-Detergent Fiber
(ADF), Acid-Detergent Lignin (ADL) and Cellulose (CEL)
Contents (%) and Dry Matter Digestibility (DMD, %) in
STANDING DEAD Vegetation on a Tall grass Prairie Watershed
Grazed by Cattle in North Central Oklahoma, 1976-78 .... 142
30. Correlation Coefficients Matrix for Chemical Components in LIVE
(L) and in STANDING DEAD (D) Vegetation on a Tallgrass
Prairie Watershed Grazed by Cattle in North Central
Oklahoma, 1976-78 144
31. Average (25 Samples/Day) Nitrogen Yield (kg/ha) in Above-
ground Vegetation Components on a Tallgrass Prairie Water-
shed Grazed by Cattle in North Central Oklahoma, 1976-78 . .145
32. Average (25 Samples/Day) Phosphorus Yield (kg/ha) in Above-
ground Vegetation Components on a Tall grass Prairie
Watershed Grazed by Cattle in North Central Oklahoma,
1976-78 147
33. Average (25 Samples/Day) Potassium Yield (kg/ha) in Above-
ground Vegetation Components on a Tallgrass Prairie Water-
shed Grazed by Cattle in North Central Oklahoma, 1976-78. . 148
34. Average (25 Samples/Day) Calcium Yield (kg/ha) in Aboveground
Vegetation Components on a Tall grass Prairie Watershed
Grazed by Cattle in North Central Oklahoma, 1976-78 .... 149
xlv
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Number Page
35. Average (25 Samples/Day) Digestible Dry Matter Yield (kg/ha)
in STANDING Vegetation on-a Tall grass Prairie Watershed
Grazed by Cattle in North Central Oklahoma, 1976-78 .... 151
36. Live Plant Chemical Composition (%) and Yield (kg/ha, Content
(%) X Biomass (kg/ha)) on Loamy and Shallow Prairie Range
Sites on a Tallgrass Prairie Watershed Grazed by Cattle in
North Central Oklahoma, 1976-78 152
37. Rank Order by Location for Dung Biomass (kg/ha, Oven-Dry) and
Dung Pat Density (No./ha) Pre-Dung-Removal and for Dung
Pat Density (No./ha) Post-Dung-Removal on a Tallgrass
Prairie Watershed Grazed by Cattle in North Central
Oklahoma, 1976-78 153
38. Average Dung Pat Biomass (kg/ha, Oven-Dry) and Density (No./ha)
on Loamy Prairie and Shallow Prairie Range Sites Pre- and
Post-Dung-Removal on a Tall grass Prairie Watershed Grazed
by Cattle in North Central Oklahoma, 1976-78 157
39. Regression Equations for Dung Biomass (kg/ha) and Dung Pat
Density (No./ha) Pre-Dung-Removal and for Dung Pat Density
(No./ha) Post-Dung-Removal on a Tallgrass Prairie Watershed
Grazed by Cattle in North Central Oklahoma, 1976-78 . . . .159
40. Correlation Coefficients Matrix for Dung Deposition and Herbage
Utilization Measures from 25 Locations on a Tallgrass Prairie
Watershed Grazed by Cattle in North Central Oklahoma,
1976-78 160
41. Rank Order by Location for Average (7 Grazing Periods) Utili-
zation (%) of Vegetation Components on a Tallgrass Prairie
Watershed Grazed by Cattle in North Central Oklahoma,
1976-78 162
42. Average Chemical Composition (%) of Dung Deposited in Differ-
ent Seasons and Collected After Different Periods of Time on a
Tallgrass Prairie Watershed Grazed by Cattle in North Central
Oklahoma, 1976-78 163
43. Average Fiber Composition (%) of Dung Deposited July 76 on a
Tallgrass Prairie Watershed Grazed by Cattle in North Central
Oklahoma 165
XV
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ACKNOWLEDGEMENTS
Special appreciation is expressed to Dr. R. D. Morrison and Dr. P. L.
Claypool of the Department of Statistics, Oklahoma State University, for
assistance in statistical analyses. The assistance of Mr. W. 0. Ree, former
Director of the USDA SEA-AR Water Conservation Structure Laboratory, in devel-
oping the head-discharge relations is gratefully acknowledged.
Analysis of runoff samples were conducted by Mrs. Wanda Smith, OSU Depart-
ment of Animal Sciences, Dr. S. L. Burks, Director, OSU Water Quality Research
Laboratory, and Dr. Dale Toetz, Toetz Water Analysis Laboratory. The soil
survey was conducted by Mr. Earl Nance (retired), USDA Soil Conservation Ser-
vice. Analyses of nutrient concentrations in dung were conducted by Dr. D.
A. Whitney, Extension Specialist, Soil Testing, Kansas State University.
Special appreciation is also expressed to the many graduate and under-
graduate students who assisted in the collection of field and laboratory data
and to Mr. Lynn R. Shuyler, Project Officer, for his guidance and counsel
during the project.
xvi
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SECTION 1
INTRODUCTION
As the demands on rangelands for meat, water and other products and uses
become more Intense, the need to understand the fundamental relationships in
rangeland ecosystems becomes more critical. Grazing by herbivores and water
production have historically coexisted on rangelands. They will continue to
coexist as long as we choose to utilize meat from grazing animals and water
from runoff and as long as rangeland managers have and use the knowledge nec-
essary to make grazing and water production compatible.
Considerable research has been conducted in the last decade on animal
waste pollution. Relatively little research has been or is being conducted
on potential water pollution from rangeland watersheds grazed by livestock.
Most of the interest in animal waste pollution has centered around point
sources of pollution (e.g., feedlots) or nonpoint sources, such as cropland
or intensively managed pastureland (e.g., dairy cattle pastures). These
areas, however, receive much greater amounts of animal wastes or fertilizer
nutrients than do rangelands. Environmental factors and relationships on
rangelands are also greatly different from those affecting feedlot, cropland
or pastureland nutrient cycling.
The need for research on water budgets and nutrient inventories and cycl-
ing on rangeland is critical and immediate. Rangelands and forest-ranges,
as defined by the Society for Range Management (1975) and USDA (1974a), could
provide either a large area for animal waste disposal or be a potentially
significant source of water pollution. The realization of a beneficial and
safe land use instead of a detrimental consequence of natural herbivore graz-
ing depends largely on the capacity of different rangelands to receive and
hold animal wastes without exceeding the acceptable level of pollutants in
water runoff.
There are 416 million hectares of rangeland and forest-range or about
54% of the total land area in the 48 contiguous states (USDA 1974a). About
338 million hectares of range are grazed by livestock. The plains grasslands
account for about 21% of all range and 62% of all U.S. grassland.
The emphasis on increasing red meat production and livestock numbers on
rangelands is increasing rapidly (USDA 1974a). The relatively high price of
grain and increased foreign demand for grain as human food have caused a
greater interest in producing more forage-fed beef. The efficiency of conver-
sion of solar energy by rangeland forage to red meat is much higher than that
from other sources of livestock feed (Cook 1977). Much of the additional
1
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forage required for forage-fed beef will come from rangeland, and its effi-
cient production will require a greater understanding of range ecosystems.
In much of the Southern Great Plains it is not uncommon for rangelands
to be seasonally overgrazed as cattle are concentrated on rangeland until
small grain crops are ready for grazing in the fall. Nationally it is common
for ranchers to rely on rangeland to produce maintenance forage when inade-
quate water, fertilizer or growing conditions significantly reduce the high
forage production usually expected from intensively managed pasture and farm
forages. Excess animals are frequently maintained on rangeland during per-
iods of low market prices because of the reluctance of livestock owners to
sell their animals at an economic loss. Drought and market price fluctua-
tions in the past, and no doubt in the future, will cause periodic long- or
short-term periods of overgrazing. Even when rangeland is properly stocked,
livestock tend to concentrate grazing and resting along watercourses unless
grazing distribution practices are applied.
Because of the greater demands on rangeland to produce red meat while
maintaining production of water of acceptable quality (P.L. 92-500) and the
limited amount of information concerning potential water pollution from range-
land watersheds grazed by cattle, this study was designed to determine on a
North Central Oklahoma rangeland watershed grazed by beef cattle (1) the
source, transfer and transformation of potential pollutants, (2) the hydro-
logic and meteorologic parameters necessary to establish the water budget
and movement of selected nutrients, (3) effects of environmental conditions
on the rate of degradation of grazing cattle dung, and (4) effects of cattle
waste concentration, chemical composition and distribution on levels of nutri-
ents in soils.
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SECTION 2
CONCLUSIONS
The amount of nonpoint source pollution contributed to receiving waters
by runoff from this watershed, representative of tallgrass prairie watersheds
grazed by cattle in North Central Oklahoma, is comparable to that from tall-
grass prairie watersheds in other parts of the United States and is minimal
when compared to other nonpoint sources of pollution, such as cropland and
fertilized pastures. Significant runoff can occur in any season, but the
season with the greatest runoff and pollution potential is spring when precip-
itation is greatest and ground cover is at the lowest level.
Sediment is the most significant pollutant and is contributed primarily
by watershed areas with no ground cover, such as cattle trails leading into
drainageways and the sides of drainageway channels. The potential danger of
pollution from chemical leaching from watershed vegetation is very low com-
pared to that of sediment and dung movement into drainageways. Direct over-
land movement of dung into stream channels is minimal because standing vege-
tation and ground litter on the deeper soils of the lower slope positions
adjacent to stream channels acts as a retardant and filter. Utilization of
standing vegetation is also relatively light in areas adjacent to stream chan-
nels.
Soil water drawdown and recharge cycles were much more consistent all
three years of the study than were precipitation amounts and distribution.
Soil water content decreases from maximum to minimum within about 60 days
(i.e., mid May to mid July) primarily due to transpiration of actively grow-
ing vegetation. Soil water content in the lower part of the soil profile is
much more consistent than that in the upper part of the soil profile. Soil
water content is greater in ungrazed areas where standing vegetation and plant
ground litter are greater than in grazed areas. Soil water use rates are
closely related to soil water availability and the amount of growing vege-
tation. As vegetation matures in late summer, soil water recharge begins
regardless of precipitation insoak.
Peak vegetation production varied each year and occurred earliest (June)
during the driest year. Accumulative production of the different plant spe-
cies classes amounts to 25 to 30% more production than peak standing crop.
Therefore accumulative production of rangeland vegetation should be used as
a measure of total production rather than peak standing crop. Productivity
of grazed vegetation is about as high as that of ungrazed vegetation. Abun-
dance of different plant species is closely related to slope position, aspect,
soil types, range sites, A horizon and total soil water content and grazing
pressure. From 80 to 90% of the variation in LIVE and STANDING DEAD
-------
vegetation can be accounted for with regression equations and independent
site factors. Large differences in plant species composition and biomass,
ground cover, herbage utilization and dung distribution can be expected on
the basis of range sites.
The average effective duration of dung biomass is about two years since
the average dung biomass on the watershed is about twice that deposited annu-
ally by grazing cattle. Chemical concentrations of N, P, K and Ca in fresh
dung decrease with time and appear to reach a steady state in about six to
eight months. Dung decomposition is apparently affected more by fragment-
ation and decomposer activity than by leaching or chemical transformation.
Decomposition appears to be slower on the xeric, shallow prairie range sites
than on loamy prairie sites. Cattle site preference for bedgrounds and rest-
ing areas has a greater influence on dung distribution and potential pollu-
tion sources than does site preference for grazing. The effect of urine on
potential pollution is insignificant because of rapid movement into the soil
or volatilization of N-compounds into the air and the absence of perennial
streams on the watershed..
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SECTION 3
RECOMMENDATIONS
RESEARCH
Additional water quality research conducted in Central Oklahoma should
be on this watershed in order to utilize the extensive data base concerning
soils, vegetation, ground cover and cattle grazing behavior and to utilize
the facilities in place for determining streanrflow and collecting water sam-
ples. A less intensive study of longer duration (e.g., 10 years) should be
continued to determine the seasonal and annual variation in water quality and
nutrient contribution from a tallgrass prairie grazed by cattle. Additional
research, in general, should be conducted on environmental and management
factors affecting dung distribution, fragmentation and decomposition and on
those practices which minimize deposition near drainageways and which speed
decomposition and nutrient cycling. Specific studies should determine 1)
effects of fertilization, burning, mowing, supplementation, insects, birds
and soil characteristics on dung fragmentation and decomposition, 2) factors
affecting seasonal chemical composition of dung from grazing animals, 3) veg-
etation-soil water relationships (i.e., infiltration and soil water use) for
major range sites, 4) changes in dung pat weight over time (i.e., decay rate),
5) factors affecting cattle site preference for bedgrounds, resting areas
and intensively grazed areas and 6) the optimum amount of vegetation needed
to minimize dung and ground litter movement into drainageways.
MANAGEMENT
All grazing management plans should incoporporate grazing distribution
and watershed management practices which minimize dung deposition and maxi-
mize standing vegetation and ground litter along drainageways. Saltgrounds
and feeding areas should be located away from drainageways. Yearlong stock-
ing rates which maintain good range condition should be determined and not
exceeded. Intensive rotation or seasonal grazing systems which produce heavy
grazing pressure along drainageways in late winter and early spring should be
avoided. Normal cattle behavior and site preference should be determined.
When practical, excessively grazed upland sites should be reserved for winter
grazing in order to maintain ground cover and best utilize the relatively
higher quality standing dead forage. Practices which encourage cattle to
trail along contours rather than directly downslope and across stream channels
should be implemented. Stream-crossing points where the soil and channel
banks are least erodable should be made more attractive or accessible to cat-
tle. Shade trees along ridgetops for summer resting areas and winter shelter,
especially tallgrasses and windbreak trees, along south-facing slopes should
be maintained.
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SECTION 4
STUDY AREA
LOCATION
The study area is located at latitude 33°N, longitude 97°W about 16 km
northwest of Stillwater, Oklahoma. Most of the watershed area is located in
the NW%, S32, T20N, R1E of the Indian Meridian. The remainder of the water-
shed is located in the southwest quarter of Section 32 and the eastern edge
of Section 31 (Figure 1). It is accessible from Stillwater during dry weather
by a direct route involving 13 km of paved roads and 6.5 km of graveled roads.
During wet weather the watershed can be reached by a 32-km drive on paved
roads.
The watershed is part of the area acquired by the Land Utilization Divi-
sion of the Resettlement Administration when the Lake Carl Blackwell dam was
constructed (Park 1937). In 1947, control of the watershed and much of the
land around Lake Carl Blackwell was transferred to Oklahoma State University.
Since that time the watershed area has been used as a research area for graz-
ing by beef cattle.
The watershed has been seasonally grazed with cows and calves for many
years prior to the study. Grazing continued during the study as before.
The area is generally not grazed during the last two weeks of April and during
the 75 days between 1 August and 15 October. The average grazing use for
the watershed during the study period was 70 to 80 animal-unit-days/ha.
Dry cows are supplemented with about 1 kg of 41% protein cottonseed meal/
hd/day from 15 October to 31 December when they are removed from the water-
shed. From late January to mid April cow/calf pairs are fed 2.7 kg of 20%
protein soybeanmeal range cubes and 1.8 kg of prairie hay per pair per day.
A dicalcium-phosphorus mineral supplement plus sodium chloride salt is pro-
vided free choice during all grazing periods.
The study area is part of the Lake Carl Blackwell watershed. Lake Carl
Blackwell provides municipal water for Stillwater. Runoff from the study
area flows into Lake Carl Blackwell, then into Stillwater Creek, Cimarron
River, Arkansas River, Mississippi River and the Gulf of Mexico.
CLIMATE
Temperature
The climate of the area is continental with hot summers and moderate
6
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WATERSHED LOCATION
Figure 1. Environmental research watershed location and vicinity map.
-------
winters. The average number of frost-free days is 206 from early April to
late October or «arly November. The average absolute maximum temperature is
40 C or higher in June, July, August and September. The average absolute
minimum temperature is -20 C or lower in December, January, February and March
(Figure 2). July and August are the hottest months; January and February
are the coldest months. The relationship between the monthly absolute maxi-
mum temperatures and absolute minimum temperatures is shown in Figure 3.
Warm (=-20 C) days are common during winter months, but cool (<10 C)
nights are rare during summer months. The average absolute maximum temper-
ature ranges from 27 C in January to 45 C in July (range of 18 C), whereas
the average absolute minimum temperature ranges from -26 C in January to 11 C
in July (range of 37 C). Freezing depth in the soil rarely exceeds 25 cm.
It is uncommon for surface soil to remain frozen for more than two or
three days during any one period except in January. In January surface soil
is commonly frozen for periods of a week or longer. Significant snowmelt on
frozen soil is uncommon.
Precipitation
Average annual precipitation is 820 ± 250 mm with about 75% occurring
during the growing season. The average monthly precipitation ranges from
about 120 mm in May to 30 mm in December, January and February (Figure 2).
Precipitation amounts vary widely from year to year and from month to month.
A climograph for the area is shown in Figure 4.
The relatively large rainfall amounts in May and early June are caused
by warm fronts from the Gulf of Mexico to the southeast. Summer and fall
rainfall is primarily from convectional thunderstorms. Cold fronts from the
northwest in late October and November are generally dry. Precipitation from
snowfall averages 25 mm per year. Snow cover on the ground averages about
10 days per year.
Relative humidity
The mean relative humidity varies from 62% in July and August to 71% in
December and January. Diurnal fluctuations in relative humidity are wide
during the summer. The maximum daily relative humidity is commonly 80 to
90% at sunrise during late spring and summer months. Several periods of rel-
atively low relative humidity occur in late fall after cold fronts pass and
high barometric pressure exists in the area.
Wind
The average daily windspeed varies from 215 to 230 km/day in April and
March to about 125 km/day or less July through October (Figure 2). Winds
are generally from the southeast in the spring and south or southwest in June
through September. Cold fronts in late fall and winter are from the north
and northwest. Calm days are rare during any part of the year.
8
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100-
I,
100-
i 80
L 60-
Wi«d
Ewp.
Ppl.-
N 0 J
finite
Ata.Nin.TMt.>
300_
2 Sol
2001
£
100
-10
-20
-30
Fall
Figure 2. Long-term (1893-1980) climate
for Stillwater, Oklahoma.
so-
o
- 40
a.
£
30-
20-
-30 -20 . -10 0 10
Abs. Win. Temp. (C)
20
Figure 3. Average monthly absolute maximum and
absolute temperatures (C), Stillwater,
Oklahoma. .
-------
30
25 -
- 20 -
|
a
15
10 -
5 -
30 60 90
Precipitation (mm)
120
150
Figure 4.
Climograph of average monthly temperature
and average monthly precipitation for
Stillwater, Oklahoma, 1893-1980.
Evaporation
Pan evaporation during the April through October growing season varies
from 150 mm/mo, in October to 280 mm/mo, in July (Figure 2). The precipita-
tion/potential evaporation ratio averages less than 1.0 every month of the
year. During late spring and summer months, surface soils dry rapidly if
the soil surface is bare or only partly covered with ground cover.
PHYSIOGRAPHY
Topography
The watershed is part of a prairie-woodland complex on undulating terrain
(Figure 5). The elevation is about 300 m. The watershed lies in the upper
reaches of the Lake Carl Blackwell watershed and is higher than much of the
surrounding area. The general slope is to the east and to the south toward
Lake Carl Blackwell and other components of the Stillwater Creek watershed.
Most streams flow to the southeast in this area. There are very few perennial
streams in the general area. There is no evidence the land has been plowed;
however, there is a small area of terraces established about 1940-1950 to
control erosion during an area reclamation project.
10
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Figure 5. Aerial view of environmental research watershed,
Noble County, Oklahoma.
The elevation of the watershed varies from 290 m at the main runoff-meas-
uring weir to 318 m at the upper end. The topography is rolling with slopes
averaging 3.6% on the upper 25% of the watershed and 5.3% on 55% of the area.
The land adjacent to the drainageways has slopes averaging 9%. The weighted
average slope for the entire watershed is 5.7%.
Topography and drainage patterns are shown in Figure 6. In addition to
the contours, the map also shows the location of all permanent reference
points for soil water and vegetation sampling, fenced exclosures, locations
of rain gages, runoff measuring stations, and access roads. The watershed
is composed of two principal drainageways which merge about 235 m upstream
from the main weir. Drainage density is 8.9 km/km2. The south drainageway
drains 51% of the watershed. The -length is 715 m and channel gradient is
2.0%. The north branch is shorter, 493 m in length, has a slightly flatter
gradient, 1.5%, and drains 42% of the watershed. The remaining 7% of the
watershed drains directly into the main drainageway, which has a 1.0% slope.
As a result of the decreased slope the main channel has a pronounced sinuos-
ity. Several bends about 100 m upstream from the main weir show evidence of
mild bank erosion during periods of high flow. The drainage network charac-
teristics as defined by the National Handbook of Recommended Methods of Water
Data Acquisition (1978) are shown in Table 1.
11
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LEGEPIO
Wottrshsd Boundary
Pond MttriMd Boundory
itoContours
Inttriitttnt ffaltrMy
:-= ACCHI Rood
i Fines
Rtcording Rain Gogl
T Runoff Caging Srotlon
A Transit Station
o Soil Votsr Stotioa
ENVIRONMENTAL RESEARCH WATERSHED
AGRICULTURAL EXPERIMENT STATION
OKLAHOMA STATE UNIVERSITY
HE 1/4 SEC. 31 AND HI 1/4 SEC. 32
rZON.RIE, NOBLE COUNTY, OKLA.
Figure 6. Topographic map of experimental research watershed in
North Central Oklahoma.
12
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TABLE 1. DRAINAGE NETWORK CHARACTERISTICS
Stream Measure Stream Order
Number of streams 30 3 1
Bifurcation Ratio 10 3 -
Total Length, m 3205 1413 504
Mean Length, m 107 471 504
Total drainage area of the watershed is 57.7 ha. Land use includes 53.8
ha rangeland, 3.6 ha cultivated land planted each year to winter wheat, and
a 0.3 ha stock water pond, located at the upper end of the north drainageway.
The pond has a drainage area of 6.9 ha, approximately 13% of the total
watershed area. During periods of low runoff the pond water level is normally
below spillway level causing all of the inflow into the pond to be retained
and thereby reducing the total research watershed area by the amount of the
pond drainage area. Runoff calculations were adjusted for the amount of run-
off retained by the pond.
ACCESS ROADS
Access roads are essential for servicing instruments and caring for live-
stock, but they present a special problem for nonpoint source pollution stud-
ies because construction activities to improve the roads may artificially
raise the level of pollution until vegetation is established in the roadside
ditches. The environmental watershed has two access roads. The north-south
road near the west boundary is a poorly drained existing field road. All of
the runoff from this road flows directly into the main watershed drainageways.
Therefore to eliminate the possibility of increasing the sediment load, this
road was left in its original condition, except for the addition of small
amounts of gravel. As a result, access to raingage RE2 was frequently dif-
ficult.
A new road was constructed along the northeast side of the watershed to
provide access to rainfall and runoff recorders at the lower end of the water-
shed. To minimize the impact of the construction activities, the road was
located on the watershed boundary, except for the hill beginning at the 310
m contour where it was located outside the watershed so runoff water draining
from the road ditches would not be caught by the runoff sampler. Because of
13
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these precautions it is believed that there was little or no impact from con-
struction activities on the quality of the water samples.
Geology
Oklahoma has rock formations ranging in age from most recent through
Precambian. Periods of regional uplift, faulting and folding have alternated
with periods when the area stood near or below sea level.
Formations generally dip to the west; however, the land surface elevation
is higher and with less relief in the western part of the state than in the
eastern part. Elevations vary from about 1400 m MSL in the Panhandle to less
than 120 m MSL in the southeastern corner of the state along the Red River.
All major streams drain to the southeast.
Central Oklahoma prairie soils, of which the study area is representative,
developed from sedimentary shales, sandstones and clays. These materials
are often bedded with horizontal strata composed of layers of varying texture.
The clays and shales are generally well supplied with bases. In the study
area sandstone outcrops are common and are readily apparent because of shrubs
and trees on fractured sandstone or sparse, xeric herbaceous vegetation on
unfractured outcrops.
Soils
The distribution of soils is shown in Figure 7. A detailed description
of the study area soils is in Appendix A. Soils of the surrounding area are
described in the Noble County Soil Survey (Brensing and Talley 1956). In
general soils of very-fine or fine-loamy, mixed thermic Vertic Haplustalfs
occupy 70% of the watershed. The proportion of soil orders is 78% Alfisols,
16% Mollisols and 6% Inceptisols. All of the soils found in the study area
are common to the general area and in about the same proportion as in the
surrounding area.
Loamy soils developed under tallgrass prairie vegetation are most common.
Soil fertility in the A horizon is high. A Bp horizon is generally present.
Soil water-holding capacity is good except on the limited area of coarse-
textured soils.
VEGETATION
About 80 to 85% of the study area is grassland (Figure 8). Most of the
plant species present in the area are those tallgrass prairie climax species
described by Bruner (1934) and Carpenter (1940). Other existing grassland
species common to lower successional stages of the tallgrass prairie have
been described by Sims and Dwyer (1965). A survey conducted and vegetation
map prepared by 0. H. Brensing and E. C. Talley in 1940 reported the dominant
vegetation to be the same climax species which were dominant when the study
was initiated.
14
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Figure 7. Soils map of experimental watershed in North Central Okla-
homa. The description of each soil is in Appendix A.
15
-------
Shrubs and trees are common along drainageways (Figure 9) and on shallow,
coarse-textured soil overlying fractured sandstone (e.g., Darnell-Stephenville
soil complex). Range sites include Loamy Prairie, Claypan Prairie, Shallow
Prairie, Shallow Savannah and Sandy Savannah. These range sites are common
throughout the surrounding area. Annual herbage production varies from 1700
kg/ha on Shallow Savannah sites to 3900 kg/ha on Loamy Prairie sites when
the range is in good condition and under average growing conditions (USDA
1974b).
At the beginning of the study a qualitative range survey indicated the
watershed was in high fair to low good range condition (J. Powell, personal
observation). Both standing and ground litter were less than average because
of relatively unfavorable growing conditions during the previous three growing
seasons and excessive amounts of precipitation during the fall and winter
periods of the same three previous years.
LAND USE
The study area has always been used for grazing, originally by buffalo
and other native herbivores, and by cattle since the late 1800's. During
the past 30 to 40 years, the area has been used by the Oklahoma State Univer-
sity Department of Animal Science for various range cow/calf beef production
experiments. The stocking rate has been about 3.5 to 4.0 ha/animal-unit-year
with one or two brief (15 to 30 days) periods of rest from grazing during
the year. During the past 30 to 40 years the area has not been mowed for
hay and has rarely burned. This history of use is representative for much
of the prairie rangeland in Central Oklahoma.
16
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Figure 8. View of grassland aspect of experimental
watershed in North Central Oklahoma.
'**'*
' am w
^r-se:'
Figure 9. View of woody vegetation along drainageways
in the experimental watershed in North
Central Oklahoma.
17
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SECTION 5
METHODS
WEATHER
Rainfall was measured at two locations selected to obtain adequate aerial
distribution of precipitation over the watershed. The gage designated as
RE-1 was located near the access road leading to the main weir. This gage
was representative of rainfall that occurred on the lower end of the water-
shed. Gage RE-2 was on the upper end of the watershed about midway between
the north and south boundaries. Both locations were in open areas that were
free from interference by trees or buildings. A 3m by 3m fenced exclosure
protected each gage from damage by cattle.
The rain gage charts were changed on a regular basis (Figure 10). The
charts were removed immediately after each rainfall event and taken to the
office for processing. The charts were read manually, using the "break-point"
technique to determine periods of uniform rainfall intensity. The data were
then transferred to computer cards.
Figure 10. Recording rain gage.
18
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Instrumentation at the Class A weather station operated by the OSU Agron-
omy Department provided additional meteorological data useful for calculating
a water budget. Instrumentation included a hygrothermograph for measuring and
recording relative humidity and air temperatures; Eppley pyronometer and Lin-
tronic integrator for measuring and recording solar radiation; and a class A
evaporation pan and 3-cup anemometer for measuring daily evaporation and wind
movement.
RUNOFF MEAbURhMENT
Runoff from the environmental research watershed was measured by flow
through a reinforced concrete triangular weir. The weir location was dictated
by the requirement of a stable soil foundation that would not allow seepage
around or below the structure and the further requirement that the channel
gradient below the structure should have sufficient slope to avoid submergence
of the wetr by backwater. The site selected met both requirements, but the
sinuosity of the channel directly upstream from the weir caused some prelim-
inary concern. However, the elevation of the weir notch was set at such a
height that the upstream channel was completely inundated at times of high
flow rates, and sinuosity of the channel was not a problem. The location of
the wler in relation to the approach and exit channels is shown in Figure 11.
Structural design of the weir was based on the standard designs recom-
mended by the USDA SEA-AR Field Manual for Research in Agricultural Hydrology
(rev 1979). The side slopes were 2:1 and the notch depth was 1.68 m (Figure
12). The top width of the weir notch was 6.72 m and the crest width was 40
cm. Figure 13 shows the plan and elevation construction drawings. Important
features were a massive base to prevent shifting of the weir and a large
stilling basin to prevent erosion downstream (Figure 14). Prior to construc-
tion, studies were made to determine if the exit channel had sufficient
capacity to conduct from the structure without submerging the weir. I he
simulation verified that the weir operated with free fall at all times.
The weir was designed for a maximum discharge capacity of Il.45m3/sec,
which is equivalent to the expected runoff rate from a hydro!ogic event with
a recurrence interval of 100 years, ihe head-discharge relations for the main
weir were developed using procedures and coefficients developed by the USUA
ShA-AR Water Conservation Structures Laboratory (1967). Field survey of the
weir included profiling of the upstream and downstream edges of the weir
crest. Discharge equations for each of five different head ranges and the
rating table developed from these equations are shown in Appendix B. It
should be noted that although tnglish units were used in the equations, the
final values of runoff rate and amount were later converted to metric units.
A continuous record of water stage at the weir was recorded by a standard
FW-1 water level recorder mounted in an Instrument shelter at the top of a 61-
cm diameter corrugated metal still well. The recorder was equipped with a
battery-powered chart drive and was operated at a chart speed of one revolu-.
tion per 12 hours. A supplemental staff gage was located 3 m upstream from
the weir to assure that the water level recorder was properly zeroed at all
times.
13
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24 Diameter
Gage Well
Figure 11. Site location of main weir.
20
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Figure 12. View of V-notch of watershed main weir.
Runoff through the pond spillway was measured by a reinforced concrete
V-notch weir with 3:1 side slopes and a crest width of 40 cm (Figure 15).
The maximum discharge capacity was 1.32 m3/sec at a head of 61 cm. Head on
the flow was recorded by an FW-1 water level recorder. A manually read staff
gage was also set up to obtain the water surface elevation in the pond.
Runoff recorders were serviced at weekly intervals or more often as need-
ed. As soon as possible after each runoff event the chart was replaced and
taken to the office for analysis. The heads and associated times were read
manually at appropriate break-point intervals and transferred to computer
cards for analysis by the University computer. The output from the computer
calculations included clock time and associated rates of runoff, rate of
change of storage due to temporary pondage upstream from the weir, runoff
per time interval, and accumulated runoff. The program also provided a flow
duration analysis that listed the peak rates and maximum volumes of runoff
for time intervals ranging from one hour to eight days.
WATER SAMPLE COLLECTION
A modified Chickasha sediment sampler described by Allen et al. (1976)
was installed beside the main weir for collecting water samples for sediment
and nutrient analysis (Figure 16). During runoff events the sampler was pro-
grammed to pump water through the intake line, and after thorough flushing
21
-------
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DOWNSTREAM END VIEW
Figure 13. Plan and elevation drawing of main weir.
-------
Figure 14. Downstream side of watershed main weir.
'&&r''*^^^i^J3$&^^^£
Figure 15. Watershed pond weir.
23
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of the intake line, deliver the water to a 1000 ml plastic bottle. The sam-
pler had the capacity to collect 24 samples at a sampling frequency that was
either head-sensitive or time-sensitive. Both approaches were used at the
environmental watershed. For the first several events the sampler was acti-
vated by a head-sensing device that caused samples to be taken at head incre-
ments of 7.6 cm on both rising and falling sides of the hydrograph. Because
this method did not obtain enough samples from small runoff events, an elec-
tronic timer was installed which permitted most samples to be taken at inter-
vals of 8 - 10 minutes. The time of sampler operation was noted automatically
by a "tic" mark on the runoff recorder chart.
Figure 16. Head gage (left) and runoff samples (right).
WATER SAMPLE HANDLING AND ANALYSES
All samples were collected within 12 hours and stored at 4 C, or frozen
until they could be analyzed. Because some types of analyses (e.g., BOD and
COD), required a larger quantity of water, it was necessary to combine two
or more successive field samples to obtain a composite sample large enough
for analysis. On several occasions, BOD tests could not be made because the
runoff event occurred on week-ends or holidays when laboratory personnel were
not available to process the samples within the specified maximum holding
time.
24
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Water quality analyses were made according to procedures outlined in
EPA Standard Methods (1974) for sediment, nitrogen, phosphorus, potassium,
COD, BOD and TOC. Water analysis was contracted to the following laborator-
ies: OSU Department of Agronomy Soil and Water Testing Laboratory; OSU Animal
Sciences Department Testing Laboratory; OSU Water Quality Research Laboratory
(Dr. S. L. Burks, Director); and Toetz Water Analysis Laboratory. A brief
summary of the procedures is outlined in Appendix C.
SOILS
Soon after the project started, we determined the Noble County Soil Sur-
vey (Brensing and Talley 1956) was not detailed enough for our needs and the
information in the Survey was in need of updating. A preliminary soil survey
of the watershed was completed in August, 1975. Using the preliminary study
as a base, we found the soil association on the watershed to be much more
complex than normally reported in soil surveys.
Consequently, we resurveyed the watershed soils using a sampling loca-
tion grid of 30 m by 60 m. The field work and mapping of soil units were
completed by December 1975.
After the proportion and distribution of the various soils were deter-
mined, 29 permanent sampling locations were arbitrarily selected for soil
and vegetation sampling. The number and distribution of locations provided
a range in site conditions for regression analyses and replications on the
major soil types in proportion to their percentage of occurrence over the
watershed.
SOIL WATER
At each location, a neutron probe access tube was driven into the soil
to the maximum depth possible. Access tube depths ranged from 22 to 137 cm
which, at most locations, coincided with solum thickness. Soil water content
at the 10-, 20-, 30-, 40-, 50-, 70-, 90-, and 110-cm depths depending on solum
thickness, were determined with a portable neutron-scattering moisture meter
(Stone et al., 1955) (Figure 17). Access tube installation was completed in
March, 1976.
Soil water determinations were made at least monthly and often weekly
depending on rainfall events and drying conditions (Figure 18). Because of
the time required to determine soil water content at all 29 locations, soil
water content was frequently determined for only seven locations. A regres-
sion equation was developed whereby the average soil water amount (cm) for
all 29 locations was predicted on the basis of the data from the seven loca-
tions.
Soil water-content (%) was determined at each of the depths in an access
tube and then multiplied by a weighting factor. The weighting factors were
used to compensate for unequal distances between depths of neutron probe read-
ings. Percent soil water at each depth was multiplied by the appropriate
25
-------
Figure 17. Equipment used to determine soil water content.
*i»?&*ivKt~&-.' ';>***''- -*«
.-'-' ^;'.:--'-v*vx:.^r^
. . ; . ..
.»»«* -' ^ ..
^ = -"'.^f.
,^s5
Figure 18. Recording neutron counts for soil water
determination.
26
-------
weighting factor as follows: lU-cm X (15-0), 2Q-cm X (25-15), 30-cm (35-25),
40-cm X (45-35j, 5U-cm X (bO-45), 70-cm X (80-60), 90-cm X (100-80) and 1lO-cm
X (120-100). The sum of these products for the determination depths at each
location was used as a measure of total soil water (cm) per profile.
2
The coefficient of determination (R ) using data from seven locations to
predict total soil profile water for the average of all 29 locations was 0.93.
The seven locations yielding the greatest coefficient of variation were
selected. Seven locations were used because that number of locations could be
sampled in a half-day period including driving time to and from the watershed
to StilIwater.
Soil cores of b-cm diameter were taken to the maximum depth possible with
a hydraulic soil core probe mounted on a pickup truck. Cores were used
to determine a soil profile description and horizon texture at each location.
composite samples of soil from the A horizon at each location were col-
lected, oven-dried at 105 u and analyzed by the ObU Department of Agronomy
Soil & water Testing Laboratory for pH, organic matter, phosphate, potash,
calcium, magnesium, sodium, and iron contents. Total and ortho-phosphate,
total and extractabie iron, extractable potassium, calcium, magnesium and
sodium, and NO..-N and ML-N were determined at all locations at two different
times in nay, T9/6. lotah nitrogen was determined at all locations on eignt
different dates during the 19/6 growing season. Organic matter content and pH
at all locations were determined at the same times as was total nitrogen in
19/6 and periodically in 19/7 and Iy78.
VEGETATION AND GKOUND COVER
Herbaceous vegetation production and species composition were determined
monthly at each of the 29 sampling areas using three, 0.5m rectangular quad-
rats. Sampling locations were predetermined along radians from the access
tube (Figure ly). vegetation sampling was done between 5 m and 15 m from the
access tube (Figure 20;.
The double-sampling method (Wilm et al. 1944) was modified and used after
a pre-sampling training period. LIVE weights of each species or species
class, SiANuING DEAD, and GROUND LlTlER (including dung and woody material;
were estimated for each sample using the weight-estimate method (Pechanec and
Pickford 19d7). Each kind of material and a dung sample were collected,
bagged and weigned from one of the three samples.
Clipping was at ground level, and no sample areas were clipped more than
once during the study. Total LIVE and SiANuING DEAD was estimated, clipped,
weighed, hand separated into LlVh and DEAD components in the laboratory, air-
dried and reweighed. Percent dry matter and the estimation correction factor
for the standing vegetation were determined from the clipped sample and used
to adjust the estimated weights for all three samples at each location.
After air-drying the collected materials to a constant weight, each mate-
rial was ground through a Wiley mill and 1-mm screen. Then Kjeldahl nitrogen,
phosphorus, potassium and calcium contents were determined (AOAC 1970).
-------
240-^
IZO«
23
Figure 19. Schematic used to randomly select plot
locations at each site.
Figure 20. Determining vegetation and ground cover.
28
-------
The LIVE and STANDING DEAD plant samples were also analyzed for ash,
acid-detergent fiber, acid-detergent lignin and cellulose (Van Soest and Wine
1968). In vivo dry matter digestibility of LIVE and STANDING DEAD plant sam-
ples was also determined using the nylon bag technique (Johnson 1969) in three
rumen-fistulated steers grazing vegetation similar in species composition
and stage of growth to that being digested (Figures 21, 22, 23 and 24).
During each monthly collection and at each clipped sample quadrat loca-
tion, percent bare ground was estimated. Soil temperature at 5 cm deep, air
temperature and relative humidity at 1 m above ground level and the corres-
ponding time of day were recorded.
SITE FACTOR EFFECTS ON VEGETATION
In 1976 the effects of slope position, aspect and length on species fre-
quency, ground cover, plant chemical composition and grazing intensity were
studied. The watershed occupies parts of three different pastures. The mod-
erately grazed watershed portion comprises about 80% of a 97-ha pasture.
The lightly grazed watershed portion comprises about 20% of a 64-ha pasture.
The small area along the western boundary includes wheat pasture and native
prairie grazed from early November to mid March. The terms, moderate and
light, merely indicate that the moderately grazed area receives heavier graz-
ing pressure than the lightly grazed area. Since both pastures are stocked
at a rate of 70 to 80 AUD/ha depending on growing conditions, the difference
in grazing intensity is primarily due to a difference in grazing distribution.
The lightly grazed portion lies at the greatest distance from water, corrals
and feeding areas in that pasture.
Near the end of a winter grazing season in late February and early March,
1976, 20 transects of variable lengths were arbitrarily located on the water-
shed (Figure 25). Five transects were located in the lightly grazed portion
and 15 in the moderately grazed portion of the watershed. Transect locations
were selected to represent the various site and vegetation conditions present
on the watershed. Most of the transects were placed parallel with the slope
and most of the transects extended from the top or near the top of a ridge
down to within 10 m of the stream channel breaks. However, adjustments in
direction or length were made to insure that the upper, middle and lower slope
sampling areas fell within a 10-m diameter stand of relatively uniform vege-
tation. Sampling areas were then selected at the upper end, middle and lower
end of each transect.
At each sampling location, three, adjacent 0.5-m2 quadrats were used to
estimate and collect STANDING DEAD and GROUND LITTER biomass (Figure 26).
Estimates of STANDING DEAD and of GROUND LITTER biomass in all three samples
were made using the weight-estimate method. One of the samples was then sys-
tematically selected for clipping at ground level and herbage collection.
Clipped samples were weighed in the field to derive an estimation correction
factor and as continuous training for the estimators. The collected STANDING
DEAD and GROUND LITTER samples were oven-dried at 50 to 60 C to a constant
29
-------
Figure 21. Nylon bags used to determine dry
matter digestibility.
Figure 22. Inserting nylon bag set through
canula.
30
-------
Figure 23. Renewing nylon bags after 48-hour digestion period.
Figure 24. Nylon bags with digestion residue before washing,
31
-------
LEGEND
(otonMd
Pond wotonMd floumlnif
no Contour*
----- mtoiMittofit vatofmy
r;r= Act.ii Hood
-i i-Fonci
. Rtcotding HOIK Gcgt
T Hmwlf 6ogii>« Slotion
A Troniit Station
a Soil four Stotlon
ENVIRONMENTAL RESEARCH WATERSHED
AGRICULTURAL EXPERIMENT STATION
OKLAHOMA STATE UNIVERSITY
DEI/4 SEC 31 ««D HWI/4SEC. )8
T20«,»IE,«OBIE IXXMTT.OU.*.
Figure 25. Location of 20 transects used to determine species fre-
quency in relation to slope position, aspect and soil
types.
32
-------
weight, ground through a Wiley mill and analyzed for Kjeldahl nitrogen, phos-
phorus, potassium and calcium contents.
Figure 26. Collecting ground litter from one of three
quadrats per transect.
Frequency of occurrence of all plant species was also determined at each
location. The 0.5-m2 rectangular frame consisted of two 0.25-m2 subdivisions.
The frame was placed four times about a center point at each slope position
resulting in eight subsamples for each sampling location. Frequency of occur-
rence for a species was considered to be the percentage of the eight subsam-
ples in which one or more plants of a particular species was found.
Concurrent with the biomass and frequency sampling, a soil sample was
collected at each sampling location. After the A horizon thickness was deter-
mined with a soil tube, a 7.5-cm dia., steel cylinder was driven into the
soil to obtain an A horizon soil core (Figure 27). The soil core was bagged
and weighed in the field, oven-dried at 105 C to a constant weight, ground
and analyzed for pH and organic matter, total nitrogen and extractable phos-
phorus, magnesium, potassium and calcium contents. The bulk density and soil
water content of the A horizon soil core was also determined. Other site
characteristics determined included aspect, percent slope, slope length, dis-
tance from ridge to sampling area, soil depth and micro-relief as flat, uni-
form slope, convex or concave.
All data were placed on magnetic tape and subjected to analysis of vari-
ance, multiple regression or correlation analyses using the Statistical Anal-
ysis System software program (Helwig and Council 1979). Differences in bio-
mass weights and chemical composition and species frequency between slope
positions in the lightly grazed area and in the moderately grazed area were
tested by analysis of variance. Prediction equations for biomass and the
33
-------
Figure 27. Collecting A horizon soil core for soil water and
chemical composition determination.
frequency of occurrence of selected species were derived by using the SAS
procedures, RSQUARE and RE6R.
RSQUARE computes all possible regression equations for the dependent
variable and specified number of independent variables. The coefficient of
determination (R2) and the independent variables in each equation are listed
in the output. The two or three sets of independent variables accounting
for the greatest percentage of variation in the dependent variable were se-
lected and tested by REGR to determine the magnitude and level of probability
for each regression coefficient. Only those regression equations with regres-
sion coefficients significant at the 10% or less level of probability were
considered. Simple linear correlation analyses were also conducted to deter-
mine relationships between frequencies of different pairs of species, between
different species frequencies and site factors and between biomass chemical
components.
HERBAGE UTILIZATION BY LIVESTOCK
Three replicates of ungrazed conditions were established by constructing
a permanent, 50 m X 100 m, cattle exclosure in February 1976 at each of three
different locations along the upper boundary of the watershed. Barbed wire
34
-------
fencing was used to exclude cattle grazing, but permit grazing by rabbits
and other native herbivores (Figure 28). Each of the exclosures was located
so no runoff or overland flow material moved into the exclosed area.
Each exclosure was also placed in an area of what appeared to be differ-
ent grazing intensity. The three intensities of grazing were arbitrarily
labelled "Light", "Moderate" and "Heavy", although no preliminary quantita-
tive data was collected before exclosure areas were chosen. An access tube
and permanent sampling location was installed within each exclosure with a
paired access tube located on the same soil type, but outside the exclosure
in a grazed area.
In addition to the three permanent exclosures, a set of three temporary
conical cages (Figure 29) were used at each of the 25 grazed locations to
determine seasonal utilization. The cages were approximately 1 m in diameter
and 1.5 m tall and constructed of woven wire, field fence. Each cage was
staked in place to prevent movement by .cattle.
About twice each year a 0.5-m2 area under each cage was sampled to obtain
the same kinds of information (e.g., soil temperature, LIVE and STANDING DEAD
biomass) as obtained from the monthly samples on grazed areas. Each of the
three cages was located along a radian in a predetermined manner so a grazed
sample was adjacent to and served as a paired sample for each caged or ungraz-
ed sample. After sampling caged areas, cages were moved to new sample areas
along radians within the 5 to 15 m area at the same access tube location.
Herbage utilization (kg/ha) for the period since caged areas were pre-
viously sampled was calculated as the difference in herbage in caged areas
minus that in grazed areas. Percent utilization was calculated as (100 X
(caged herbage - grazed herbage residue))/(caged herbage). The procedures
used to determine utilization using cages were generally similar to those
described on p. 70 of Range Techniques (NAS-NRC 1962).
DUNG DEPOSITION AND DEGRADATION
A belt transect, 1-m wide, along both sides of each of three radians
from 5 m out to 15 m from the access tube was established at each of the 25
grazed locations. All dung pats within the 2 m X 10 m belt transect area
were counted. The number of dung pats per hectare was calculated for each
location. A composite sample of dung from 5 to 10 pats was collected for
chemical analyses and dry matter determinations.
In March 1977 all dung was removed by hand from the three, 0.5-ha exclo-
sures, bagged, air-dried and weighed to determine dung biomass (kg/ha) in
the three areas. Removing the dung also provided three dung-free, ungrazed
areas.
In 'April and early May 1977 all dung pats were removed, air-dried and
weighed from within the 30-m diameter circle around each of the 25 grazed
sampling locations. This provided an estimate of dung biomass per hectare,
a measure of dung distribution on the watershed, and reduced the large
35
-------
Figure 28. One of three exclosures constructed on
watershed.
Figure 29. One of 75 movable cages used to determine
herbage utilization by grazing cattle.
36
-------
variation in GROUND LITTER estimates between samples. Continued counting of
dung pats within the three, 2 m X 10 m belt transects at each location during
each sampling period provided an estimate of the rate of dung pat accumulation
and the time (months) necessary to re-establish an equilibrium between dung
pat deposition and degradation.
Livestock grazing patterns on the watershed were determined periodically
throughout the study period. The herd was followed for 4- to 5-hour periods
on 10 occasions including four different seasons when dung pats were marked
for a dung degradation study. In October 1977 the herd was observed contin-
uously for 48 hours. From October 1977 until the end of the study the loca-
tion of the herd and the time of day were noted each day the watershed was
visited. All observations were mapped on a watershed map.
In July 1976, July and September 1977, and January and May 1978, in the
middle of each month, the cattle herd was followed without interference as
the herd moved about the watershed and adjacent parts of the pasture enclosing
the watershed. The locations of 45 to 50 fresh dung pats were marked in place
with aluminum markers and mapped on a map of the watershed (Figure 30).
Figure 30. Collecting dung pat to determine change
in chemical composition after a known
period of time after deposition.
During each occasion about half of the dung pats were dropped and marked
in a 4-to 5-hour period in one morning with the remainder dropped and marked
the following morning in about the same amount of time. Five dung pat samples
were collected on the day of deposition during each of the five deposition
periods. These included samples numbered 1, 7, 13, 19, and 25 in order of
time of deposition. Five more samples were collected each collection period
37
-------
30, 60, 120, 180 and 240 days after the day of deposition. Each time, every
sixth sample was bagged and taken to the lab for chemical analyses. All dung
samples were analyzed for total N, P, K and Ca. Dung samples collected in
1976 were also analyzed for acid-detergent fiber, acid-detergent lignin and
cellulose.
38
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SECTION 6
RESULTS AND DISCUSSION
WEATHER
Meteorological and Runoff Data
Meteorologic and runoff data for the environmental watershed are present-
ed in Appendix D for each day during the period from April 1, 1976 through
December 31, 1979. Maximum and minimum air temperature are self-explanatory.
Relative humidity is the average of 24 hourly readings between 0000 and 2400
hours. Solar radiation is the total solar radiation during the 24-hour per-
iod. Wind travel is the total wind movement as recorded by a totalizing 3-cup
anemometer installed with its axis 30 cm above the rim of the Class A evapor-
ation pan according to standard operating procedures for Class A stations.
Pan evaporation is the amount of evaporation from the Class A evaporation
pan. Rainfall is the total precipitation, usually in the form of rainfall,
measured by recording gages RE-1 and RE-2. Runoff is the total volume, ex-
pressed in depth uniformly distributed over the watershed, as calculated by
integrating the hydrograph observed at the main weir at the outlet of the
watershed.
Missing data in Appendix D indicate that either the instrument had not
yet been installed, or that the instrument was inoperative on that date.
For example, the recording hygrothermograph for measuring relative humidity
was not put into service until September 1976. Also the Eppley pyronometer
and Lintronic integrator for measuring solar radiation were not available
until September 18, 1976. There are unavoidable gaps in the record due to
malfunctions of both of these instruments. Also, evaporation pan data were
available only during the frost-free months, usually from mid-April to mid-
October, because the Class A pan was taken out of service during freezing
conditions.
Temperature
Daily and mean monthly temperatures during the study period were within
the range of average long-term temperatures for the Stillwater area. Vege-
tation growth is closely associated with extremes in temperature, especially
the absolute minimum in January and the mean maximum in July (Powell et al.
1982). The degree of transpiration and subsequent soil water use are closely
associated with the kind of vegetation present and the leaf area index.
Therefore, the absolute maximum and absolute minimum temperatures per 7-day
period during the study period are shown in Figure 31.
39
-------
AMJJASONDJFMAMJJASONDJFMAMJJASQND
1976
1977-
1978-
Figure 31. Weekly absolute maximum and minimum temperatures (C) during study period.
-------
In general the maximum temperatures were not as high and the minimum
temperatures were not as low as the long-term average. The absolute maximum
temperature did not exceed 40 C in July, August and September and the absolute
minimum temperature did not fall below -20 C in January as it usually does.
The range between long-term average, absolute maximum and absolute minimum
temperatures is about 50 C in January and 35 C in July. During the study
period the range in these temperatures was only about 20 C in January and
July.
WATER
Precipitation and Runoff
In an attempt to graphically show the relationship between seasonal pre-
cipitation and runoff during the study period, precipitation and runoff data
per 10-day period are shown in Figure 32. Periods of 10 days were chosen as
a compromise between maximizing the number of individual periods shown and
trying to graphically isolate the effects of individual weather fronts passing
through the area.
The limited number of runoff events is readily apparent. None occurred
during the first 13 months of the study. The first runoff event produced
the greatest amount of runoff. In that 10-day period about 25% of the 160+
mm precipitation moved off the watershed. All other 10-day periods had less
than 60 mm of precipitation. The five 10-day periods with runoff after May,
1977 each received between about 45 and 60 mm of precipitation. Two of the
seven 10-day periods receiving more than 45 mm of precipitation did not pro-
duce runoff. Although runoff events were infrequent, runoff occurred at least
once during spring (April - May), summer (June - August), fall (September -
November) and winter (December - March) seasons.
Precipitation per 7-day period was also computed. The precipitation
class distribution, in 10-mm increments, is shown in Figure 33. There were
167 weeks during the study period. No precipitation fell in 48 weeks and
less than 10 mm fell in 109 weeks or 65% of the total weeks of study period.
Generally any rain of less than 10 mm is absorbed by dead or by live and dead
tall grass prairie standing vegetation and ground litter. This water is usual-
ly rapidly evaporated and does not affect plant growth or soil water recharge.
When aboveground plant biomass is excessive (8,000 - 10,000 kg/ha), even rains
of more than 10 or 15 mm will be ineffectual.
In this study the average aboveground plant biomass on the watershed at
one time varied from 2500 to 6000 kg/ha depending on the season. The lowest
amount usually occurred in very late winter after a long period of litter
decomposition and before biomass replacement by new growth.
Monthly Summary of Rainfall and Runoff
Table 2 presents monthly summaries of rainfall and runoff at the environ-
mental and the hydrology research watersheds from April 1976 through December
1979. It is clear that rainfall was uniformly distributed over the environ-
mental watershed. The rainfall amounts recorded by gages RE-1 and RE-2 were
41
-------
ro
160
140
120
3
ct
100
B 80h
o
o
2 60
a.
40
20
Jl
n
Runoff
Al« 'J 'J'A'S'0'N'O'J'F'M'A'M'J'J'A'S'O'N'D'J'F'M'A'M'J 'J 'A'S'O'N D
1976 « 1977 « 1978
Figure 32. Precipitation and runoff for 10-day periods during study period.
-------
60
50
40
30H
20H
10
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 ISO 160 170
Precipitation Classes (mm/week)
Figure 33. Number of weeks per precipitation class during
study period.
not significantly different, although there was a very slight tendency for a
greater amount to be recorded by RE-2 on the west, or upper end of the water-
shed.
Rainfall was below normal during the study period. The long-term average
rainfall for Stillwater for the period 1893 - 1975 is listed in the first
column of Table 2. The table shows that 30 months of the 44-month study per-
iod had rainfall amounts less than the long-term Stillwater average. By
years, rainfall was 41% less than normal in 1976; 13% less in 1977; and 18%
less in 1978. Only 1979 had rainfall greater than normal, with 7% greater.
For the 44-month period the total rainfall was 16% less than normal.
Rainfall at the environmental watershed was slightly greater than at
the two grassland hydrology research watersheds located 24 km away in a north-
easterly direction (also 24 km north of Stillwater). There was considerable
variation from year to year, but for the entire period the environmental
watershed received 8% more rainfall than the hydrology research watersheds.
Runoff from the environmental watershed was less than from either of
the hydrology research watersheds. For the entire period runoff was 9% less
than from watershed WH-3 (37 ha) and 33% less than from watershed WH-1 (6.8
ha). The comparison between the environmental watershed and watershed WH-3
is important because WH-3 is comparable to the environmental watershed in
size, vegetation cover, and grazing management. Thus it should be noted that
runoff production from the environmental watershed was lower than from water-
shed WH-3, despite the fact that rainfall was 8% greater. The comparison
with watershed WH-1 is less valid because that watershed is much smaller.
More importantly, it is seriously overgrazed and has compacted soils due to
overstocking, resulting in consistently larger runoff amounts.
43
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TABLE 2. MONTHLY RAINFALL AND RUNOFF AMOUNTS, ENVIRONMENTAL AND HYDROLOGY
RESEARCH WATERSHEDS, OKLAHOMA STATE UNIVERSITY
Rainfall (mm)
Month
Year: 1976
April
May
June
July
August
September
October
November
December
TOTALS
Year: 1977
.January
February
March
April
May
June
July
August
September
October
November
December
TOTALS
Year: 1978
January
February
March
April
May
June
July
August
September
October
November
December
TOTALS
Still water
Average
85.1
120.4
92.0
70.6
67.8
96.3
96.3
51.8
34.0
714.3
28.4
31.8
54.1
85.1
120.4
92.0
70.6
67.8
96.3
96.3
51.8
34.0
828.6
28.4
31.8
54.1
85.1
120.4
92.0
70.6
67.8
96.3
96.3
51.8
34.0
828.6
RE-1
62.0
79.9
24.1
63.8
50.6
78.2
39.9
10.2
4.5
413.2
15.3
30.3
51.9
52.3
251.2
29.8
100.5
54.2
57.6
36.2
34.1
6.8
720.2
26.1
64.8
35.7
36.7
121.7
103.0
36.5
58.7
31.8
57.9
90.0
11.4
674.3
RE- 2
61.8
77.4
21.6
68.1
53.4
89.6
39.8
10.2
5.6
427.5
15.3
29.0
52.8
52.2
259.6
27.9
96.2
52.8
56.5
38.4
34.1
7.3
722.1
23.1
61.9
37.9
37.9
117.2
107.7
37.9
57.7
32.8
59.2
94.7
10.9
678.9
RH-1
96.3
53.8
15.2
32.5
42.9
106.9
46.0
5.3
2.3
401.2
15.2
39.4
38.6
74.9
224.5
81.0
33.3
88.1
92.2
21.6
51.3
7.4
767.5
17.3
60.5
36.3
44.2
129.8
56.9
52.8
60.7
16.3
26.9
92.5
11.9
606.1
RH-3
86.4
50.6
17.3
33.5
39.6
99.8
45.0
7.6
2.3
382.1
15.2
39.4
39.4
71.9
211.8
81.3
31.8
89.2
84.1
20.6
50.0
7.4
742.1
19.1
57.9
35.8
44.7
122.9
66.3
49.0
60.5
24.4
27.7
91.9
15.2
615.4
Runoff (mm)
WE-1
0.00
.1.96
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1.96
0.00
0.00
0.00
0.00
59.43
0.00
2.75
0.00
0.00
0.00
0.00
0.00
62.18
0.00
3.40
0.18
0.00
2.48
6.23
0.00
0.00
0.00
0.00
1.52
0.00
13.81
WH-1
6.76
0.23
0.00
0.00
0.00
0.61
0.79
0.00
0.00
8.39
0.00
0.66 '
1.45
5.72
103.43
1.37
0.58
0.00
72.21
0.00
3.23
0.00
118.65
0.20
46.00
1.32
1.32
6.27
0.00
0.00
0.00
0.00
0.00
0.00
0.00
55.11
WH-3
4.34
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
4.34
0.00
0.18
0.41
1.78
69.85
0.25
0.13
0.00
0.10
0.00
0.56
0.00
73.26
0.00
7.06
4.17
4.78
21.31
0.00
0.00
0.00
0.00
0.00
0.00
0.00
37.32
(Continued)
44
-------
TABLE 2. (Continued)
. __ . . . .... - . -
Month
Year: 1979
January
February
March
April
May
June
July
August
September
October
November
December
TOTALS
Still water
Average
28.4
31.8
54.1
85.1
120.4
92.0
70.6
67.8
96.3
96.3
51.8
34.0
828.6
Rainfal
RE-1
39.5
8.1
94.0
53.5
124.1
130.0
141.7
69.8
56.4
37.6
77.2
47.0
878.9
1 (mm)
RE-2
35.0
9.2
94.6
49.6
123.5
131.8
153.7
76.7
60.2
34.8
78.7
45.2
893.0
Runoff
RH-1
33.8
8,6
102.1
59.9
87.4
120.9
52.8
72.9
37.1
38.4
81.8
45.2
740.9
RH-3
34.5
10.7
98.0
57.7
81.3
120.7
50.3
72.6
34.3
36.6
77.0
41.4
715.1
WE-1
8.
0.
19.
2.
33.
10.
27.
0.
0.
0.
0.
0.
101.
35
00
18
18
28
36
00
00
00
00
84
54
73
WH
1.
0.
32.
8.
28.
16.
0.
0.
0.
0.
0.
0.
86.
(mm)
-1
57
00
08
48
52
21
00
00
00
00
00
00
86
WH-3
7.
0.
41.
9.
12.
11.
0.
0.
0.
0.
0.
0.
81.
49
00
00
22
67
13
00
00
00
00
00
00
51
----- -- - -
Raingage and Watershed
RE-1
RE-2
RH-1
RH-3
WE-1
WH-1
WH-3
Note:
Raingage No
Raingage No
Raingage No
Raingage No
Code:
. 1, Environmental
. 2, Environmental
Research Watershed
Research Watershed
. 1, Hydrology Research Watershed W-l
. 3, Hydrology Research Watershed W-3
Runoff Recorder, Main
Weir, Environmental
Runoff Recorder, Culvert Weir,
Runoff Recorder, Culvert Weir,
Hydrology
Hydrology
Research
Research
Research
Watershed
Watershed W-l
Watershed W-3
1. Environmental Research Watershed is located 14 km northwest of Stillwater.
2. Hydrology Research Watersheds are located 24 km north of Stillwater.
3. Stillwater average rainfall is for the period 1893 - 1975.
4. Environmental Research Watershed was activated April 1, 1976.
45
-------
Table 3 is a summary of the number and magnitude of rainfall events and
related runoff events for each calender year of the study. There were a total
of 274 rainfall events, of which 42 resulted in runoff. The ratio of runoff
events to rainfall events is of particular interest. In 1976 only one of 20
rainfall events resulted in runoff. At that, the runoff was almost insignif-
icant. In 1977 and 1978 there was an average of one runoff event for every
nine rainfall events. The total observed runoff was five times greater in
1977 than in 1978, however. During 1979, when rainfall was higher than normal
there was a runoff event for each 3.3 rainfall events. These data rather
dramatically point up the vagaries of precipitation occurrence in the Great
Plains region, and emphasize the importance of a hydrologic data base having
a sufficiently long duration to eliminate erroneous conclusions due to vari-
ations in the precipitation cycle.
TABLE 3. SUMMARY OF RAINFALL AND RUNOFF EVENTS (APRIL 1976 - DECEMBER
1979), ENVIRONMENTAL RESEARCH WATERSHED, OKLAHOMA STATE
UNIVERSITY
Rainfall
Runoff
Year
No of Largest Observed Percent of No of Largest Observed
Events Event Total Long-Term Events Event Total
mm mm Average mm mm
1976*/
1977
1978
1979
40
77
84
73
39.5
101.6
51.3
75.0
420.4
722.2
676.6
886.0
59
87
82
107
2
9
9
22
0.97
44.27
5.82
23.60
1.96
62.18
12.44
101.73
-* Period includes April - December only
Annual Maximum Rainfall Events
In hydrology the largest event of the year is referred to as the annual
maximum. This event is of interest because the maximum value of either rain-
fall or runoff is used to develop an annual series by which the frequency of
occurrence, or return period, of events of specified magnitude can be esti-
mated.
The outstanding annual events observed in this study occurred on May 20,
1977; June 5, 1978; and July 17, 1979. Tables 4, 5, and 6 present a detailed
analysis of the rainfall and runoff from each of those events, including ante-
cedent rainfall, intensity of rainfall and accumulated amounts, and the rate
and amount of runoff for various times throughout the rainfall and runoff
period.
46
-------
TABLE 4. ANNUAL MAXIMUM RUNOFF EVENT FOR 1977, ENVIRONMENTAL RESEARCH
WATERSHED, OKLAHOMA STATE UNIVERSITY
Antecedent Conditions
Date Rainfall Runoff Date
Mo-Day (ran) (ran) Mo-Day
Rainfall
Time Intensity
of Day (mm/h)
Accum.
(mm)
Runoff
Date Time
Mo-Day of Day
Rate
(ntn/h)
Accum.
(mm)
EVENT OF MAY 20-21, 1977
Rain Gage RE-1
5-4 2.79 0.0
5-5 26.67 0.0
5-15 1.78 0.0
5-16 19.30 0.0
5-17 7.62 0.0
5-19 21.59 0.0
Total Watershed Area:
Watershed Conditions:
5-20
5-21
57.7 ha
94% native
1845
2010
2025
2035
2055
2105
2115
2125
2137
2150
2158
2208
2215
2240
2247
2255
2308
2315
2325
2400
0037
0047
0057
0115
0210
0230
grass
0
1
6
1
12
56
30
9
25
121
19
11
19
18
8
28
11
21
15
0
0
0
32
24
3
0
range,
.00
.27
.10
.52
.95
.39
.48
.14
.40
.92
.05
.17
.56
.79
.63
.70
.68
.84
.24
.51
.76
.00
.00
.64
.81
.76
and
0.
0.
2.
2.
6.
16.
21.
22.
27.
54.
56.
58.
60.
68.
69.
73.
76.
78.
81.
81.
82.
82.
87.
94.
98.
98.
00
51
03
28
60
00
08
60
68
10
64
67
96
83
85
66
20
74
28
53
04
04
37
74
30
55
6% wheat. Native grass was in good condition with
average composition of: 13% tall grass; 16% midgrass;
5% shortgrass; 31% other grass; 31% forbs; 4% shrubs.
Note: Watershed has one 0.18 ha pond with 6.87 ha
drainage area. Accumulated runoff
is discharge from main
outlet weir
not include runoff water retained
Total watershed yield,
was 47.02 mm.
in last column
only
by the
and does
pond.
corrected for pond effect
To convert runoff in mm/h to m /s,
multiply by
0.1597
.
5-20 2120
2122
2126
2130
2134
2138
2145
2150
2154
2158
2202
2204
2208
2212
2216
2220
2224
2226
2230
2234
2238
2245
2256
2301
2312
2322
2332
2343
2400
5-21 0010
0021
0034
0050
0106
0118
0125
0129
0133
0138
0156
0210
0226
0246
0304
0323
0343
0405
0427
0500
0544
0642
1010
1146
1532
0.
3.
6.
8.
8.
8.
9.
14.
28.
34.
40.
41.
38.
31.
25.
19.
14.
13.
10.
9.
8.
8.
7.
7.
8.
8.
7.
6.
4.
3.
2.
1.
1.
1.
1.
2.
3.
5.
6.
4.
3.
2.
1.
1.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
00
17
37
05
79
13
70
93
37
42
21
60
17
93
55
53
27
28
92
65
84
23
69
69
10
25
97
98
37
40
41
80
32
22
70
77
66
15
15
85
55
59
80
29
94
66
48
35
25
18
13
02
02
00
0
0
0
0
1
.2
3
4
5
7
10
11
14
16
18
19
20
21
22
22
23
24
25
26
28
29
30
32
33
34
35
35
.00
.10
.38
.89
.47
.03
.05
.04
.43
.54
.06
.43
.09
.41
.34
.86
.95
.44
.22
.91
.52
.53
.98
.62
.09
.44
.81
.18
.80
.47
.00
.43
35.84
36.17
36
36
36
37
37
39
40
.45
.70
.96
.29
.77
.47
.44
41.25
41
42
42
43
43
43
43
43
43
44
44
44
.98
.47
.82
.08
.28
.43
.61
.76
.91
.14
.22
.27
47
-------
TABLE 5. ANNUAL MAXIMUM RUNOFF EVENT FOR 1978, ENVIRONMENTAL RESEARCH
WATERSHED, OKLAHOMA STATE UNIVERSITY
Antecedent Conditions Rainfall Runoff
Date Rainfall Runoff Date Time Intensity Accum. Date Time Rate Accum.
Mo-Day (mm) (mm) Mo-Day of Day (mm/h) (mm) Mo-Day of Day (mm/h) (mm)
EVENT OF JUNE 5, 1978 '
Rain Gage RE-1
5-21 11.7 0.00 6-5 0345 0.00 0.00 6-5 0550 0.00 0.00
5-26 4.8 0.00 0400 6.10 1.52 0551 0.94 O.Q1
5-27 49;3 0.91 0442 1.45 2.54 0552 3.80 0.05
5-28 4.6 1.57 0458 0.95 2.79 0553 4.54 0.12
6-4 0.5 0.00 0505 97.97 13.22 0554 5.04 0.20
0515 6.10 15.24 0555 4.87 0.28
0520 118.87 25.15 0600 4.76 0.68
0530 10.67 26.92 0602 4.33 0.83
0540 1.52 27.17 0604 4.19 0.97
0558 33.02 37.08 0612 4.67 1.56
0638 2.67 38.86 0615 4.41 1.79
0705 4.52 40.89 0618 4.02 2.00
0730 0.00 40.89 0622 3.61 2.25
0908 1.24 42.67 0631 2.65 2.73
0640 1.92 3.07
0648 1.39 3.29
0657 1.13 3.48
0702 0.97 3.56
0706 0.86 3.63
Total Watershed Area: 57.7 ha 0714 0.75 3.73
Watershed Conditions: 94% native grass range, and 0718 0.64 3.78
6% wheat. Native grass was in good condition with 0722 0.62 3.82
average composition of: 13% tallgrass; 16% midgrass; 0731 0.53 3.91
5* shortgrass; 31% other grass; 31% forbs; 4% shrubs. 0740 0.42 3.98
0749 0.35 4.04
Note: Watershed has one 0.18 ha pond with 6.87 ha
drainage area. Accumulated runoff in last column 0758 0.30 4.09
is discharge from main outlet weir only and does 0806 0.24 4.12
not include runoff water retained by the pond. 0815 0.21 4.16
Total watershed yield, corrected for pond effect 0824 0.19 4.19
was 5.82 mm. 0832 0.16 4.21
0841 0.14 4.24
0850 0.13 4.25
0859 0.12 4.27
0904 0.11 4.28
0908 0.10 4.29
0917 0.09 4.30
1000 0.07 4.35
1100 0.03 4.39
1200 0.02 4.42
To convert runoff in nrn/h to m3/s, multiply by 0.1597. 1300 0.00 4.43
48
-------
TABLE 6. ANNUAL MAXIMUM RUNOFF EVENT FOR 1979, ENVIRONMENTAL RESEARCH
WATERSHED, OKLAHOMA STATE UNIVERSITY
Antecedent Conditions
Date Rainfall Runoff Date
Mo-Day (ran) (mm) Mo-Day
Rainfall
Time Intensity Accum.
of Day (mm/h) (mm)
Runoff
Date Time
Mo-Day of Day
Rate
(mm/h)
Accum.
(mm)
EVENT OF JULY 17, 1979
Rain Gage RE-1
7-05 42.9 1.24 7-17
7-06 8.9 2.03
7-07 0.03
Rain Gage RE- 2
7-05 44.2 1.24 7-17
7-06 8.4 2.03
7-07 0.03
Total Watershed Area: 57.7 ha
Watershed Conditions: 94% native
Native grass was in good condition
of: 13% tall grass; 16% midgrass;
grass; 31% forbs; 4% shrubs.
0255 0.0 0.00
0300 79.2 6.60
0305 109.7 15.75
0315 94.5 31.50
0325 79.2 44.70
0330 79.2 51.31
0340 59.4 61.21
0350 33.5 66.80
0400 6.1 67.82
0410 7.6 69.09
0453 7.0 70.61
0515 6.9 73.15
0545 3.6 74.93
0700 1.0 76.20
0255 0.0 0.00
0300 143.3 11.94
0305 143.3 23.88
0315 134.1 46.23
0325 102.1 63.25
0330 64.0 68.58
0340 53.3 77.47
0400 5.3 79.25
0410 15.2 81.53
0440 1.5 82.30
0515 8.5 85.85
0700 2.3 87.63
grass range, and 6% wheat.
with average composition
5% shortgrass; 31% other
Note: Watershed has one 0.18 ha pond with 6.87 ha drainage
area. Accumulated runoff in last
main outlet weir only and does not
column is discharge from
include runoff water
retained by the pond. Total watershed yield, corrected for
pond effect was 24.18 mm.
To convert runoff in mm/h to m /s,
multiply by 0.1597.
7-17 0317
0318
0319
0320
0322
0324
0326
0331
0332
0334
0338
0340
0342
0346
0356
0403
0411
0418
0424
0433
0441
0448
0456
0503
0512
' 0520
0527
0534
0541
0549
0556
0602
0611
0619
0626
0634
0659
0730
0800
0920
1105
1236
1415
1700
1830
2000
2400
0.00
0.88
3.78
5.14
7.76
13.47
19.38
21.10
25.11
30.18
31.15
31.11
29.67
27.40
18.78
12.74
8.01
5.62
4.64
3.60
2.86
2.46
2.02
1.91
1.74
1.54
1.46
1.32
1.21
1.10
0.99
0.94
0.84
0.75
0.66
0.62
0.44
0.31
0.25
0.13
0.07
0.04
0.03
0.02
0.01
0.01
0.00
0.00
' 0.00
0.05
0.12
0.32
0.53
1.30
3.04
3.40
4.37
6.41
7.38
8.45
10.35
14.13
15.98
17.36
18.16
18.68
19.29
19.72
20.03
20.33
20.56
20.84
21.06
21.23
21.39
21.54
21.70
21.82
21.92
22.05
22.16
22.24
22.32
22.54
22.74
22.88
23.13
23.30
23.38
23.45
23.52
23.54
23.56
23.60
49
-------
The annual events can be put into better perspective if they are com-
pared to historical values available in the hydrology literature. Table 7
lists rainfall intensity frequencies for rainfall durations of 5 minutes to
2 hours for return periods of 2 to 100 years. These data were compiled for
the Stillwater, Oklahoma vicinity from National Weather Service publications
by Frederick, Myers, and Auciello (1977) and Hershfield (1961). Table 7 was
used as the basis for determining the return periods of rainfall intensities
at the environmental watershed.
Table 8 shows the observed rainfall intensities and the estimated return
periods for the annual maximum events. One of the events, June 5, 1978, had
only moderate rainfall intensities, with no return periods greater than one
to two years. The May 20, 1977 event had higher intensities throughout with
a return period of 5 years for a 2-hour duration. The return periods for
the entire storm ranged between 2 and 5 years. The most intense storm of
the entire study was the July 17, 1979 event, which had very high intensities
throughout its life. The return period was 25 to 50 years for a 30-minute
duration and 25 years for a 60-minute duration. Even the intensity for the
2-hour duration had a return period of 10 years. Storms of this duration
and intensity usually cause a considerable amount of erosion. The sediment
load carried by runoff from this storm is discussed elsewhere in this report.
Annual Maximum Runoff Events
The results of a flow duration analysis for each of the annual maximum
events (Table 9) show the maximum discharge rate and the runoff distribution
for various times from 1 hour to 8 days. In general, about half of the runoff
from the environmental watershed occurred in the first two hours. Runoff
was essentially completed after six hours, illustrating the ephemeral nature
of the watershed.
For purposes of comparison, Table 9 also contains similar flow duration
analyses for hydrology research watersheds WH-1 and WH-3. As noted previously
there is a great deal of similarity in cover and management between hydrology
watershed WH-3 and the environmental watershed WE-1. However, direct compar-
ison is difficult because of differences in rainfall due to geographic separ-
ation of the watersheds. The May 20, 1977 event is the only one common to
all three watersheds. It may be noted though that all three watersheds had
approximately half of the runoff in the first two hours and that runoff was
completed in the first six hours.
Comparing watersheds WE-1 and WH-3, it may be noted that the maximum
discharge rate for the environmental watershed was more than twice as large
as the hydrology watershed, while the total amount of runoff was considerably
less. After 1 day the runoff from WE-1 was 44.28 mm compared with 55.39 mm
from WH-3. This may possibly be explained by the topography of the two water-
sheds. The environmental watershed had a much shorter time of concentration
because its main drainageway has two principal branches. The hydrology water-
shed has a single main waterway and therefore has a longer time of concentra-
tion, resulting in a lower peak discharge rate than the environmental water-
shed.
50
-------
TABLE 7. NWS PRECIPITATION^/ INTENSITY FREQUENCY TABLE FOR STILLWATER,
OKLAHOMA
Return
Period
yr.
2
5
10
25
50
100
Precipitation Intensity For Duration of
5 min.
128
168
189
222
244
267
10 min.
196
137
157
183
203
221
15 min.
90
117
134
155
172
188
30 min.
mm/hr
64
84
98
116
130
143
60 min.
41
56
66
78
87
96
2 hr.
26
35
41
48
54
60
Reference: Frederick, R.H., V.A. Myers and E.P. Auciello.
Five to 60-minute Precipitation Frequency for the Eastern
and Central United States. NOAA Technical Memorandum NWS
HYDRO-35, June, 1977.
' Precipitation values were converted to Annual Series by applying
conversion factors listed in Table 1 of reference publication.
TABLE 8. PRECIPITATION INTENSITY AND RETURN PERIOD FOR ANNUAL MAXIMUM
RUNOFF EVENTS, ENVIRONMENTAL RESEARCH WATERSHED, OKLAHOMA
STATE UNIVERSITY
Duration
5 min. 10 min. 15 min. 30 min. 60 min. 2 hr.
20 May 1977 Event
Intensity (mm/hr) 152 137
Return Period (yrs) 25 5
110
2 5
65
2
49
2 5
34
5
5 June 1978 Event
Intensity (mm/hr) 118
Return Period (yrs) 1 2
118
1 2
75
1
53
1
53
1 2
37
1 2
21
1 2
17 July 1979 Event
Intensity (mm/hr) 143 149 140 126 79 42
Return Period 25 5 10 10 25 25 50 25 10
51
-------
TABLE 9. ANNUAL MAXIMUM DISCHARGES AND ANNUAL MAXIMUM VOLUMES OF RUNOFF FOR SELECTED TIME
INTERVALS, ENVIRONMENTAL AND HYDROLOGY RESEARCH WATERSHEDS, OKLAHOMA STATE UNIVERSITY
tn
ro
Year
Maximum
Discharge
Date Rate
m3/s
Maximum for Selected Time
1 Hour
Date Vol.
mm
2 Hours
Date Vol.
mm
6 Hours
Date Vol .
mm
12 Hours
Date Vol .
mm
1 Day
Date Vol .
mm
2 Days
Date Vol.
mm
8 Days
Date Vol.
mm
ENVIRONMENTAL RESEARCH WATERSHED WE-1
1976
1977
1978
1979
5-12 0.07
5-20 6.63
6-5 0.80
7-17 4.96
5-12 0.36
5-20 21.52
6-5 3.34
7-17 18.21
5-12 0.55
5-20 29.64
6-5 4.04
7-7 20.99
5-12 0.92
5-21 42.76
6-5 4.42
7-17 23.11.
HYDROLOGY RESEARCH
1976
1977
1978
1979
4-20 0.03
5-21 1.66
2-12 0.15
6-9 0.29
4-20 1.25
5-21 25.71
2-12 7.10
6-9 9.83
4-20 2.17
5-21 33.54
2-12 13.02
6-9 13.24
4-20 3.21
5-21 71.67
2-12 26.52
6-9 14.79
HYDROLOGY RESEARCH
1976
1977
1978
1979
4-20 0.12
5-21 3.06
5-28 0.37
3-22 0.97
4-20 1.04
5-21 19.35
5-28 3.15
3-22 7.36
4-20 1.78
5-21 26.13
5-28 5.80
3-22 13.43
4-20 2.94
5-21 52.19
5-28 12.24
3-22 23.89
5-12 1.02
5-21 44.10
6-5 4.43
7-17 23.47
WATERSHED WH-1
4-20 3.73
5-21 73.11
2-12 30.60
5-3 16.54
WATERSHED WH-3
4-20 3.35
5-21 54.96
5-28 15.38
3-22 25.81
5-12 1.02
5-21 44.28
6-5 4.43
7-18 23.61
4-20 4.45
5-21 73.45
2-13 33.24
5-4 25.40
4-20 3.76
5-21 55.39
5-28 18.08
3-23 27.78
5-12 1.02
5-22 44.28
6-6 4.50
5-4 28.36
4-20 4.45
5-21 75.66
2-13 33.58
5-4 28.51
4-20 3.76
5-21 55.71
5-28 18.08
3-23 28.37
5-12 1.02
5-28 59.69
6-6 4.50
6-9 32.02
4-20 5.96
5-27 88.29
2-13 33.58
6-9 28.51
4-28 4.12
5-30 67.89
5-28 18.08
4-10 40.99
-------
Sediment and Nutrient Sampling and Analyses
Table 10 contains a list of the sediment and nutrient constituents that
were analyzed from samples collected from the runoff discharge. Also listed
are the number of runoff events for which each constituent was sampled during
the years 1977 - 1979. In general, except for sediment, each of the nutrients
was sampled two to four times during each year, with the median number of
events being three. We believe this number is sufficient to indicate the
degree of nonpoint source pollution by runoff from the environmental water-
shed. Sediment was collected only once in 1978 but in 1979, sediment samples
were collected during seven runoff events, including the outstanding hydro-
logic event of-July 17, 1979. BOD was sampled only in 1977. Due to the dif-
ficulty and cost of having these samples analyzed for BOD, this test was dis-
continued after 1977,.
TABLE 10. SAMPLING FREQUENCY FOR SEDIMENTS AND NUTRIENTS
Nutrient
Sampled
Sediment
N in Sediment
NH. - N
NO;: - N
N0« - N
Dissolved P
Total P
Dissolved K
Total K
COD
TOC
BOD
No. of
1977
4
4
4
4
0
4
3
3
0
3
4
3
Runoff Events Sampled
1978
1
2
2
2
1
3
3
1
3
3
3
0
in Year
1979
7
3
3
3
3
3
3
3
3
3
3
0
Detailed sediment and nutrient analysis data for each event sampled are
listed in Appendix E. These basic data are point values of the sediment and
nutrient content of each sample, together with the runoff rate and the accum-
ulated runoff at the time each sample was obtained. The total sediment loss
or nutrient loss was calculated for each event by an integration procedure
which involved multiplying the average nutrient concentration during a time
element by the amount of runoff that occurred during that time element.
The tables included in Appendix F illustrate the calculation procedure
for determining the amount of sediment lost during each time interval of the
event. The other nutrient losses were calculated by the same procedure, but
the detailed calculations are not included with this report.
53
-------
Summary of Sediment Loss by Runoff
Table 11 shows sediment loss rates for the 12 runoff events in terms of
watershed area and also in terms of the amount of runoff. As expected the
larger runoff events produced the greatest sediment losses per hectare. How-
ever, when expressed in terms of kilograms per hectare per millimeter of run-
off, the sediment loss rates were quite similar for most of the events. The
weighted average sediment/runoff ratio was 17.38 kg/ha/mm.
TABLE 11. SUMMARY OF SEDIMENT LOSS BY RUNOFF, ENVIRONMENTAL RESEARCH
WATERSHED, OKLAHOMA STATE UNIVERSITY
Runoff
Date
Rainfall
mm
Runoff
mm
Sediment
Loss
kg/ha
Sed/ Runoff
Ratio
kg/ha/mm
20 May 77
23 May 77
27 May 77
1 July 77
14 Nov. 78
18 March 79
22 March 79
10 April 79
2 May 79
9 June 79
5 July 79
17 July 79
101.55
38.61
22.35
45.72
47.75
20.32
55.37
26.92
99.31
75.95
52.07
82.55
44.27
13.56
1.85
1.72
0.94
0.56
16.43
1.85
32.03
8.76
2.36
23.47
687.6
193.7
6.9
32.1
15.53
14.28
3.75
18.68
7.30
TOTALS 668.47 147.80 2569.1
Weighted Average Sediment/-Runoff Ratio = 17.38 kg/ha/mm
Two events differed significantly from the weighted average. The May 27,
1977 ratio of 3.75 kg/ha/mm was extremely low, which could be attributed to
the small amount and low intensity of the rainfall. The July 17, 1979 event
had the highest loss ratio, 31.43 kg/ha/mm. As previously noted this storm
had a very high intensity and was classified as having a return period of 25
to 50 years for a duration of 30 minutes. Undoubtedly the high sediment loss
rate was associated with the high rainfall intensity.
While the loss rates from the May 20, 1977 and July 17, 1979 events may
seem high, they are low when compared with sediment losses reported for sev-
eral grazed, tallgrass prairie pastures near Chickasha, Oklahoma as reported
by Olness et al. (1975). They observed that one event with 89 mm rainfall
54
-------
caused sediment losses of 4.6 metric tons/ha from one watershed and 11.4 mt/ha
from another watershed. Both events were for durations of less than 24 hours.
In contrast, the sediment production from the May 20 event on the environ-
mental watershed was 0.69 mt/ha. The high intensity storm of July 17 caused
a sediment loss of only 0.74 mt/ha. Both of these amounts were significantly
less than reported at the Chickasha watersheds.
The source of sediment is an important consideration in nonpoint source
pollution studies. Sediment in the streamflow may come from soil erosion on
the watershed or it may come from erosion caused by cattle paths, or by over-
cutting at points where concentrated flow enters the small tributaries of the
main stream, or by erosion of the banks of the main stream when flows reach
sufficient depth and velocity to dislodge loosely held soil particles from
steep banks.
Bare or poorly vegetated areas in the watershed may yield significant
amounts of sediment during high intensity rainfall due to the impact of rain-
drops on unprotected soil. This type of erosion should be at a minimum on a
well-managed range I and because of an abundance of herbaceous plant cover.
We believe very little of the sediment loss from the environmental watershed
was caused by raindrop impact on bare areas. Frequent observations while
walking over the watershed during rainfall showed that the water passing over
and through the vegetation by overland flow was relatively free of sediment.
The first sign of sediment in the runoff occurred at the overfall or head
cut that existed where cattle trails entered the main stream. Another source
of sediment was the field access road at the west side of the watershed.
Stream bank erosion is less subject to control by good range management
practices. If the channel grade is not completely stabilized, or if the banks
are steep, a considerable amount of sediment may be injected into the flow
because of sloughing of the banks. Inspection of the watershed during rain-
fall leads us to the conclusion that bank erosion was largely responsible for
the sediment load that was collected at the lower end of the watershed.
Nitrogen Losses by Runoff
Nitrogen losses were evaluated for nine runoff events. The results are
summarized in Table 12. The nitrogen loss in the sediment accounted for prac-
tically all of the losses of N. Dissolved nitrogen losses in the forms of
NH.-N, N03-N, and NOp-N were very low and could be considered insignificant.
Considering the fact this watershed have never received an application of
commercial fertilizer, this finding is not unexpected.
The results of two comparable studies, one in Oklahoma and one in west-
central Minnesota, may be used for comparison with the total N loss observed
on the environmental watershed. Olness et al. (1975) studied the influence of
management practices on two tall grass watersheds at Chickasha, Oklahoma, on
losses of nitrogen and phosphorous in the runoff from July, 1972 to July 1973.
Total N loss from a rotationally grazed pasture was 1.59 kg/ha. A continuous-
ly grazed pasture lost 7.87 kg/ha of N. Total nitrogen loss from the environ-
mental watershed for 1977, the only year for which complete data exists,
amounted to 4.64 kg/ha which compares quite well with the Chickasha results.
55
-------
TABLE 12. SUMMARY OF NITROGEN LOSS BY RUNOFF, ENVIRONMENTAL RESEARCH WATERSHED, OKLAHOMA STATE
UNIVERSITY
en
en
Runoff
Date
20 May 77
23 May 77
27 May 77
1 July 77
5 June 78
21 June 78
18 March 79
22 March 79
2 May 79
Sediment
TN-N-i/
Kg/ha
3.229
0.965
0.083
0.196
0.013
0.248
0.689
Kg/ha/mm
0.0729
0.0712
0.0449
0.1140
___
0.0236
0.0151
0.0215
NH
Kg/ha
0.0359
0.0126
0.0046
0.0014
0.0085
0.0001
0.0037
0.0978
0.0393
4-N
Kg/ha/mm
0.0008
0.0009
0.0025
0.0008
0.0019
0.0011
0.0066
0.0060
0.0012
Filtrate
NO
Kg/ha
0.0834
0.0149
0.0055
0.0014
0.0039
0.0001
0.0010
0.0077
0.0042
3-N
Kg/ha/mm
0.0019
0.0011
0.0030
0.0008
0.0008
0.0012
0.0017
0.0005
0.0001
N02-N
Kg/ha Kg/ha/mm
-JJ
*3/
0.00005 0.00009
0.00100 0.00006
* *
TN-N is total nitrogen.
jyNutrient not evaluated during this event.
Nutrient not detected during this event.
-------
In Minnesota, Timmons and Holt (1977) measured nitrogen losses in sur-
face runoff from a tallgrass prairie during 1970 - 1974. The average annual
total N loss for that 5-year period was 0.84 kg/ha. The lowest and highest
observed annual losses were 0.11 and 1.71 kg/ha, respectively. Thus the loss
observed at the environmental watershed was more than twice as large as the
highest annual loss observed in Minnesota. However, the amount and character
of the rainfall may have been a factor. Average annual rainfall in Minnesota
during the study was 595 mm compared with 722 mm at Stillwater in 1977.
Phosphorus and Potassium Losses by Runoff
Table 13 is a summary of phosphorus (P) and potassium (K) losses by run-
off. Dissolved P was measured for 10 events and total P was determined for
nine events. The data are shown in units of kilograms per hectare of water-
shed area for comparison with other studies, and also in units of kilograms
per hectare per millimeter of runoff for comparison of events with different
amounts of runoff.
Total P losses from the environmental watershed were in the same order
of magnitude as had been observed at the Minnesota watershed by Timmons and
Holt (1977). Total P losses for 1977, 1978, and 1979 were 0.010, 0.006, and
0.228 kg/ha, respectively. The 5-year average in the Minnesota study was
0.11 kg/ha, with individual years ranging from 0.01 to 0.25 kg/ha per year.
The total P losses at the environmental watershed were much less than reported
by Olness et al. (1975) for the Chickasha, Oklahoma study. Losses there
amounted to 1.27 kg/ha from the rotationally grazed pasture and 4.60 kg/ha
from the continuously grazed pasture. None of the pastures had been ferti-
lized with commercial fertilizer.
Potassium losses for the environmental watershed also compared favorably
with the Minnesota watershed. Total potassium losses amounted to 1.06 kg/ha
in 1978 and 5.28 kg/ha in 1979. In Minnesota the range was from 0.25 to 3.98
kg/ha, with an average value of 1.74 kg/ha. In terms of total K losses per
millimeter of runoff from the environmental watershed, the losses for the
six events in 1978 and 1979 ranged from 0.08 to 0.26 kg/ha/mm.
BOD, COD, and TOC in Runoff
Biological oxygen demand (BOD), chemical oxygen demand (COD) and'total
organic carbon (TOC) are commonly used indicators of water quality. The sum-
mary of the analyses for these parameters is presented in Table 14. BOD was
evaluated for three events in 1977. COD was determined for three events in
each year of 1977, 1978, and 1979. TOC was evaluated for four events in 1977
and three each in 1978 and 1979.
The total BOD load for 1977 was 1.40 kg/ha with a range of 0.021 to 0.065
kg/ha/mm of runoff. The highest COD load occurred in 1979 with a total of
34.87 kg/ha. The lowest COD was in 1978 with 4.63 kg/ha. There was a sub-
stantial increase in the COD load per millimeter of runoff over the years.
For 1977 the COD loss ranged from 0.31 to 0.45 kg/ha/mm; in 1978 it ranged
57
-------
TABLE 13. SUMMARY OF PHOSPHORUS AND POTASSIUM LOSS BY RUNOFF, ENVIRONMENTAL RESEARCH WATERSHED,
OKLAHOMA STATE UNIVERSITY
Runoff
Date
20
23
27
1
5
tn
00
21
14
18
22
2
May
May
May
July
June
June
Nov
March
March
May
77
77
77
77
78
78
78
79
79
79
Dissolved P
Kg/ha
0.0064
0.0033
0.0002
0.0004
0.0014
0.0001
0.0006
0.0006
0.0139
0.0381
Kg/ha/mm
0.0001
0.0002
0.0001
0.0002
0.0003
0.0007
0.0007
0.0011
0.0008
0.0012
Total P
Kg/ha
0.0064
0.0047
0.0004
(1)
0.0055
0.0001
0.0008
0.0022
0.0828
0.143
Kg/ha/mm
0.0001
0.0004
0.0002
0.0012
0.0004
0.0009
0.0039
0.0050
0.0044
Dissolved
Kg/ha
1.
0.
0.
0.
0.
0.
0.
0.
4569
5093
0909
0549
0349
0174
4106
9644
K Total K
Kg/ha/mm Kg/ha
0.
0.
0.
0.
0.
0.
0.
0.
0329 1/
0376
0492
0320
0.9160
0.0188
0371 0.1273
0311 0.1441
0250 2.4579
0301 2.682
Kg/ha/mm
0.2072
0.2089
0.1354
0.2573
0.1496
0.0838
I/
Analysis not conducted during this event.
-------
en
vo
TABLE 14. SUMMARY OF BOD, COD, AND TOC LOSS BY RUNOFF, ENVIRONMENTAL RESEARCH WATERSHED,
OKLAHOMA STATE UNIVERSITY
Runoff BOD
Date Kg/ha Kg/ha/mm
20 May 77 0.938 0.0212
23 May 77 0.345 0.0255
27 May 77 0.120 0.0649
1 July 77 -/
5 June 78 "
21 June 78
14 Nov 78
18 March 79
22 March 79
2 May 79
Kg/ha
13.532
5.241
0.832
3.954
0.062
0.614
0.946
19.745
34.875
COD
Kg/ha/mm
0.306
0.386
0.450
0.894
0.690
0.653
1.690
1.202
1.089
Kg/ha
4.515
1.756
0.362
0.242
0.710
0.028
0.282
0.322
7.238
9.123
TOC
Kg/ha/mm
0.102
0.130
0.196
0.141
0.161
0.304
0.300
0.574
0.440
0.285
I/
Analysis not conducted during this event.
-------
from 0.65 to 0.89 kg/ha/mm; and in 1979 it ranged from 1.20 to 1.69 kg/ha/mm.
The TOC load also showed an increase over the three years in about the same
proportion as the COD.
HYDROGRAPHS
Rainfall histograms and runoff hydrographs are shown in Figures 34 - 43
for the most significant hydrologic events in 1977 - 1979. These figures
also show the time of collection and sediment load of each runoff sample and
the accumulated amounts of sediment and runoff. As a general rule the sedi-
ment load was closely associated with the runoff rate. This relationship is
illustrated quite clearly in Figures 34 and 43, which portray the rainfall,
runoff and sediment relationships for the outstanding hydrologic events of
May 20-21, 1977 and July 17, 1979.
Figures 44 and 45 show the variation of the BOD, COD, and TOC parameters
with the runoff from the events of May 20, 1977 and June 5, 1978, respective-
ly. The BOD decreased significantly during the runoff period for the May 20
event. This would indicate organic matter was transported from the watershed
with the first flush of runoff. The COD parameter value also decreased sharp-
ly from its initial value of 40 mg/1, but stablilzed at an average value of
26 mg/1 approximately 30 minutes after the beginning of runoff. The TOC val-
ues followed the same pattern, decreasing from an initial value of 13.5 mg/1
to an average value of 9.4 mg/1 after 30 minutes.
The pattern for the June 5, 1978 event was somewhat different from the
May 20, 1977 event because the runoff rate was much lower. The peak runoff
rate for June 5 was 0.68 m3/sec compared with 6.27m3/ sec for May 20. In
the June 5 event the COD value peaked when the runoff rate peaked, increasing
from an initial value of 80 mg/1 to a maximum of 140 mg/1 and then stabili-
zing at an average of 50 - 55 mg/1 approximately one hour after the peak run-
off rate. The initial value of the TOC parameter was the highest (20.4 mg/1).
TOC decreased rapidly to 15.6 mg/1 reaching its lowest value (13.9 mg/1)
about one hour after runoff began, and then "increased to an average value of
17 mg/1. Examination of the basic data in Appendix E shows that TOC was a
less sensitive parameter than the COD parameter for the runoff events
observed at the environmental watershed.
SOILS
Soil Depth and Texture
Soil depth and horizon thickness and texture composition for each of
the 29 sampling locations are shown in Figure 46. Detailed profile descrip-
tions of the sampling locations are shown in Appendix G.
Soil depths ranged from 26 to 150 cm with an average of 75±35 cm. All
soils included an Al horizon and one or more B horizons. Thickness of the A
horizon ranged from 10 to 45 cm with an average of 17±7 cm. Most of the soils
had a loam Al horizon texture. jOther Al horizon textures included silt loam
and sandy loam. The average soil texture composition for Al horizons were
47±11% sand, 30±8% silt, and 23±4% clay.
60
-------
42
36
i30
124
8
18
JC.
*»s.
J 12
|
6
- 0
Rainfall = 101.5 mm
Runoff = 44.3 ram
Sediment =688 kg /ho
5600 -|
- 4800 -
- 4000--
a>
-3200§-
-2400^-
-1600 -
-800 -
1400
1200
I
IOOOS1
800
6002
400
200
2000 2100 2200 2300 2400 0100 0200
Moy20,l977 May 21,1977
Figure 34. Hydrograph for event of May 20-21, 1977.
2.0-
-3000
01-
300
250o
2003
1
100 1
50
0500 0600 0700 0800 0900 1000 1100
May 23,1977
Figure 35. Hydrograph for event of May 23, 1977.
61
-------
0.25
-E
-0.201-
^
Intensity \
Accumulated
Runoff
1200 -i
1000 H
12
800 -
600!
8
400 -
4 I
200 -2
1700 1800 1900 2000 2100 2200 2300
November 14,1978
Figure 37. Hydrograph for event of November 14, 1978.
62
-------
0.05
S
0.041-£
=0.03
o
lo.02
.20.1
0.01
L- 0
0.3 - 30 -
iO.2
-6000
30
251
8
203
I
3
10
0800 0900 1000 1100 1200 1300 1400
Morch 18, 1979
Figure 38. Hydrograph for event of March 18, 1979.
2.5
2.0
0.5
-5000 -
-4000--
-3000
1,
- 2000 «- 400f
-1000
L- 0
1000
800i
6001
200
0300 0400 0500 0600 0700 0800 0900
March 22, 1979
Figure 39. Hydrograph for event of March 22, 1979.
63
-------
3300 -|60
2750
-2200-
50";
-40!
Ql
6
-11650 e-\
-1100 -
30"
20
-550
10
1600 1700 1800 1900 2000 2100 2200
April 10, 1979
Figure 40. Hydrograph for event of April 10, 1979.
o -Jo
2.0-
-600
-5000 -500f
100°
300<
200
00
0800 0900 1000 1100 2000 2100 2200 2300
May 2, 1979
Figure 41. Hydrograph for event of May 2, 1979.
64
-------
12
1.8
1.6- -101
8
ii.2
£0.8
0.6
0.4
0.2
0
§
£
L- 0
6000 -1300
0100 0200 0300
0400 0700 0800
June 9,1979
0
0900 1000
250 _
200!
ISOf
s
100 I
50
Figure 42. Hydrograph for event of June 9, 1979.
23
§
-------
45
2120
2200
2300
Hour - May 20, 1977
2400
Figure 44. Variation of BOD, COD and TOC with
runoff from event of May 20, 1977.
0.8
0.6
0.4
0.2
.
E
I2
.
0
- 0
0400 0500 0600 0700 0800 0900 1000
June 5,1978
0 J
40
30 _
o
20 £
10
Figure 45. Variation of COD and TOC with runoff event
of June 5, 1978.
66
-------
Soil Profile Locations
o>
1 '°-
-c 30-
0-40-
O 50-
60-
O 70.
CO
80-
29 5
Al Al
60/26/M 74/10/16
B2 B2
46/37/19 82/6/12
6
Al
61/26/13
B2
48/33/19
Cr Cr Cr
12
Al
50/30/20
B2
62/14/24
Cr
48/33/19
% Sand/% Silt/% Clay
IS
Al
43/37/20
B2t
41/32/27
B3
52/27/21
Cr
4
Al
44/34/22
B2t
38/26/36
Cr
28
Al
57/21/22
B2
50/23/27
Cr
16 II 22
Al
39/35/26
B2
30/36/24
Cr
Al
38/22/20
B2I
37/37/26
B22
43/11/46
B3
30/42/28
Cr
Al
34/38/28
B2t
40/24/36
B3
IS/53/32
Cr
3
Al
45/32/23
B2lt
46/18/36
B3/Cr
48/22/30
Cr
Figure 46. Soil profiles showing soil depth, horizon thickness and texture of the 29
sampling locations. Soil profiles for the ungrazed (U) locations inside
exclosures and adjacent grazed (G) locations are also shown.
-------
Soil Prof i le Locations
10-
20-
30-
"40-
0 50-
60-
f "
?-
0 90-
100-
O no-
CD
120-
130-
140-
150-
2O
Al
49/31/20
B2lt
40/25/35
B22t
26/38/36
Cr
',
7 10 19 2 23
Al
41/32/27
B2lt
30/32 /3B
B22t
36/32/32
Cr
Al
42/32/26
B2lt
30/36/34
B22t
12/44/44
B3t
10/33/57
Cr
48/33/19
'i "* /^
k Sand/% Silt/% Clay
Al
44/36/20
B2I1
45/21/34
822 t
29/22/49
Cr
Al
41/33/26
B2lt
18/28/54
B22t
14/60/26
Cr
Al
43/29/28
Bit
29/29/42
B2II
23/22/55
B22t
14/24/62
Cr
1
Al
46/30/24
B2lt
46/22/32
B22t
36/22/42
Cr
14 13
Al
51/27/22
Bl t
30/28/42
82 It
26/25/49
B22t
20/21/59
B23t
I2/82/ 6
Cr
Al
66/10/24
A3
42/26/32
B2lt
50/32/18
B22t
40/31/29
Cr
21
Al
47/29/24
Bit
38/29/33
B2lt
11/31/58
B22t
10/18/72
Cr
Figure 46. (Continued)
-------
Soil Profile Locations
CM
VO
10 -
^C 20-
^30-
40 -
.C
-30-
s-
70 -
- 8O -
0
CO 90-
100-
U
8
Al
40/35/25
B2lt
26/33/41
B22t
37/29/34
G
9
Al
40/34/26
B2t
33/35/32
Cr
Cr
48/33/
% Sand/ % Silt/
u
26
Al
43/28/29
B2i
27/36/37
Cr
% Clay
G
24
Al
26/44/30
Bit
33/31/36
B2t
26/34/40
Cr
u
17
Al
37/33/30
B2lt
30/33/37
B22t
19/36/45
Cr
G
18
Al
42/30/28
B2
40/26/34
B3
33/31/36
Cr
U G
25 27
Al
38/30/32
B2I1
35/31/34
B22t
24/37/41
Cr
Al
36/37/27
B2t
33/34/33
B3
29/42/29
Cr
Figure 46. (Continued)
-------
The textures of B horizons varied more widely than did those of A hor-
izons. The B2 horizons included loam, clay loam, silt loam, silt clay and
silt clay loam.
Soil Chemical Composition
Soil Type
Soil samples were collected from the A horizon at all 29 locations aver-
aged by soil type (Table 15). Soil acidity was in the neutral range (i.e.,
6.1 to 7.0) for all soil types. Nitrate-N was less than 5 ppm for all soils.
Ammonium-N ranged from 10 ppm to 22 ppm. Total phosphorus was relatively
uniform except for an average of 438 ppm for Stephenville soils. Extractable
phosphorus was low (i.e., 4 to 7 ppm) in all soils except Stephenville (16
ppm) and Darnell (17 ppm) soils. Both of these soils are shallow with a sandy
loam A horizon. The concentrations of extractable cations (i.e., calcium,
magnesium, potassium and sodium) were relatively uniform. The lowest values
for calcium and magnesium concentrations were from Stephenville and Darnell
soils.
Watershed Averages
Data from the 25 grazed locations represent a watershed average. Chem-
ical composition averages and standard deviations for the samples collected
periodically in 1976 and again in the fall of 1979 are as follows: 2.6 ±
0.53% organic matter, 0.11 ± 0.058% total (Kjeldahl) nitrogen, 6.0 ± 2.48
ppm extractable phosphorus, 335 ± 60 ppm extractable potassium, 2310 ± 580
ppm extractable calcium, 67 ± 37 ppm extractable sodium, 6.4 ± 4.8% total
iron, 51 ± 30 ppm extractable iron and 290 ± 90 ppm extractable magnesium.
Slope Position
In March 1977 soil samples were collected from 60 locations randomly
located throughout the watershed. Twenty transects from the top to the bot-
tom of different slopes were used with soil samples collected at the upper,
middle and lower slope positions. Chemical composition values by slope posi-
tion are shown in Table 16.
Values for pH and total N were generally similar for all slope positions.
Values for organic matter were slightly lower and values for extractable P,
Ca and Mg were slightly higher at the middle slope position. Extractable K
values increased slightly from the lower to upper slope positions. In general
there were little differences in soil chemical va.lues due to slope position.
Sampling Date
Soil samples collected between spring and fall seasons in 1976 showed a
decrease in organic matter and a corresponding increase in total N in late
May (Table 17). The changes in organic matter and total N occurred just after
appreciable growth in plants began. There was no trend with season for pH.
70
-------
TABLE 15. AVERAGE CHEMICAL COMPOSITION OF A HORIZON OF SOILS AT 29 PERMANENT SAMPLING LOCATIONS
Soil,/
No. -i/
1
2
4
5
6
7
11
12
13
15
0/ Nitrogen (ppm)
pH
6.3
6.1
6.3
6.4
7.0
6.3
6.3
6.2
6.2
6.2
B.I.
7.1
6.9
6.8
7.0
7.1
7.0
7.1
7.0
6.9
6.9
N03-N
&
5
5
5
5
5
5
5
5
5
NH4-N
10
22
14
11
13
13
16
14
14
17
Phosphorus (ppm)
Total
375
375
354
344
375
363
438
313
348
396
Extr.
5
17
4
5
5
5
16
7
5
7
Extractable Cations
Ca
2300
2073
2130
2930
3300
2420
2250
2370
2610
2840
Mg
660
415
530
580
440
570
375
655
640
520
K
340
420
398
280
360
393
445
348
384
366
(ppm)
Na
90
74
143
83
77
80
73
82
80
87
y/Soil numbers correspond to soils described in the report.
I'Buffer Index.
-'All soil samples contained less than 5 ppm N03-N.
-------
TABLE 16. CHEMICAL COMPOSITION (X ± SD) OF A HORIZON OF SOILS AT
DIFFERENT SLOPE POSITIONS ON GRAZED, TALLGRASS PRAIRIE
WATERSHED IN NORTH CENTRAL OKLAHOMA, MARCH 1977
Slope
Soil Chemical Component
pH
Organic
Matter
(*)
Total
N
(«
Extr.
P
(ppm)
Extr.
K
(ppm)
Extr.
Ca
(ppm)
Extr.
Mg
(ppm)
Upper
sd
Middle
X
sd
Lower
X
sd
6.3
0.3
6.4
0.3
6.4
0.2
Average
5? 6.4
sd 0.3
2.5
0.4
2.4
0.5
2.5
0.5
2.5
0.5
0.12
0.05
0.13
0.03
0.13
0.05
6.9
3.2
7.3
5.1
6.5
3.1
6.9
3.8
414
166
361
132
343
85
373
128
2447
780
2532
616
2469
580
2483
659
59
21
64
26
60
17
61
21
Soil Water
Seasonal Trends
Total Soil WateiTotal soil water in the soil profile during the 32-
month sampling period varied from a low of about 90 mm in August of each
year to a high of 200 mm in late May of 1977 and 1978 (Figure 47). Al-
though soil water sampling did not begin until May of 1976, the relatively
low amount of precipitation received in April and May of 1976 indicates the
highest total soil water value in May, 1976 was probably about that shown on
the first sampling date in Figure 47.
Sampling dates in Figure 47 include data from all 29 locations and data
from six or seven locations adjusted by regression equations to predict the
29-location watershed average. Based on all these data we calculate the soil
water storage capacity of the watershed soil to be about or slightly greater
than 110 mm. Although no soils were totally depleted of soil water, it is
unlikely natural evapotranspiration would reduce the total soil water in the
soil much below the lowest figures shown.
The soil water depletion and recharge patterns were relatively consistent
each of the three years. Soil water depletion was very rapid in late spring
72
-------
TABLE 17. A HORIZON, SOIL FACTORS (X ± C.V.[X]) ON A NORTH CENTRAL OKLAHOMA TALL6RASS PRAIRIE
WATERSHED GRAZED BY CATTLE, 1976
CO
Factor
PH
Buffer Index
Organic Matter
Nitrogen
Total
NH4
N03
Units 12 April
6.3±8
7.0±1
% 2.74±21
ppm 1200±25
ppm 16±50
ppm 3
Day
2 May 25 May 22 June 20 July 17 Aug. 14 Sept.
6.2±5 6.1±8 6.2±21 6.2±5 -« I/ 6.1±5
7.0±1 6.9±1 7.0±1 7.0±1 6.8±1
2.88±18 1.87±30 2.40±23 2.59±15 2.73±26 2.75±18
1300±15 1700±24 950±37 1300±27 1600±28 1200±21
12±42
3
11 Oct.
6.1±5
6.8±1
2.68±21
1300±23
I/
Analysis not conducted.
-------
200
~ 180
E
o
o
160
140
120
100
29 Locations
7 Locations
A'M'J'J'A'S'O'N'D'J'F'M'A'M'J'J'A'S'O'N'D'J'F'M'A'M'J'J'A'S'O'N'D
1976 " 1977 " 1978
Figure 47. Total soil water content (mm) for watershed based on average of 29 locations or
regression equation using seven representative locations.
-------
during the period of most rapid plant growth. Based on the work by Powell
et al. (1982) in the tallgrass prairie near El Reno, Oklahoma, most of the
soil water depletion was due to transpiration rather than evaporation. Re-
charge occurred after the low point in August regardless of the amount of
precipitation received. In general maximum depletion occurred in about three
months whereas recharge occurred during the remaining nine months of the year.
Soil Water by DepthThe relationships between soil water in the upper
35 cm of the profile where the bulk of the root biomass is located, the soil
water in the 35- to 120-cm layer of the watershed and the total soil water
in the watershed soil (0-120 cm) are shown in Figure 48. Soil water values
for the 35- to 120-cm layer are averages from soils with variable depths,
many of which did not extend to 120 cm. The values of total soil water are
therefore not averages, but sums of values for soil water in the 0- to 35-cm
layer plus values for soil water in the 35- to 120-cm layer. The total soil
water patterns in Figure 47 and Figure 48 differ because Figure 48 includes
only values from dates when all 29 locations were sampled.
The upper 35 cms of soil averaged 52±18 mm of soil water, whereas the
35- to 120-cm layer averaged 71±14 mm of soil water or 19 mm more than the
upper 35 cm of soil. Soil water recharge peaked earlier in the upper soil
than in the subsoil during the winter of 1976-77. This is partly a reflec-
tion of percolation and partly a reflection of the greater soil water-holding
capacity of the finer-textured subsoils. Unless soil water is sampled within
two or three days after precipitation during the growing season, transporta-
tion rapidly depletes surface soil water. During the winter, surface soils
lose soil water very slowly.
The effect of precipitation and soil water depletion on percent soil
water at different depths in the soil profile is shown in Figure 49. In gen-
eral percent soil water was greater and more consistent at lower depths.
The A horizon, represented by soil water values at the 10-cm depth, had con-
sistently less soil water than horizons at lower depths. Soil water at the
30-cm level was increased by light to moderate amounts of precipitation in
the fall and winter and rapidly depleted by growing vegetation during the
growing season.
The effect of significant root absorption and transpiration of soil water
was also very evident at the deeper levels in the profile. Regardless of
the amount of rainfall in early and mid summer, soil water was rapidly deplet-
ed between June and August. The similar percentages for soil water at peak
recharge are indicative of similar clay contents in the B horizons of most
soils on the watershed.
° The average soil water contents (%) at different depths for each soil
water sampling location are shown in Figures H-l, H-2, H-3, H-4, and H-5 in
Appendix H.
Effect of Grazing
The average soil water contents at all depths in the soil profile were
consistently greater where grazing was excluded during the study period than
75
-------
200
ISO
160
140
EI20
E
£100
o
CO
80
60
40
20
A'M'J'J'A'S'O'N'D'J'F'M'A'M'J'J'A'S'O'N'D'J'F'M'A'M'J'J'A'S'O'N'D1
1976
1977-
1978-
Figure 48. Average soil water content (mm) in upper 35-cm and lower 35-cm to 120-cm
sections of watershed soil.
-------
A 'M
J'J'A'S'0'N'D'J'F'MA'M'J'J'A'S'O NDJFMAMJJASOND
1976 " 1977 » 1978-
Figure 49. Change 1n soil water content (%) at different depths over time in relation to
precipitation and runoff.
-------
where grazing was allowed (Figure 50). Although soil characteristics (e.g.,
texture) for the paired soil water sampling locations differed slightly, the
differences in soil water content were significant at the 0.01 level and ap-
pear to be due primarily to vegetation cover. No significant differences in
surface soil bulk density were determined.
The average (i.e., 30 sampling dates between June 1976 and October 1978)
standing, aboveground vegetation (kg DM/ha) for ungrazed and grazed areas
were 3160 ± 750 and 1730 ± 830, respectively. The difference in herbaceous
ground litter was greater than that shown for total ground litter because
most of the dung was removed by hand from within the ungrazed exclosures.
The average amount of dung removed from the exclosures was 640 kg DM/ha.
Although transpiration was undoubtedly greater on ungrazed areas because
of greater average live biomass (1610 ± 730 kg DM/ha, ungrazed; 1050 ± 440
kg DM/ha, grazed), much greater insoak resulted in greater average soil water
contents on ungrazed areas. This is indicated by the fact that soil water
contents in the upper 15 cm of soil were not greatly different. Most of the
differences were due to the water contents in the finer-textured B horizons.
Greater root biomass in the ungrazed areas would cause greater soil water
use from the A horizon where root concentrations are greater.
The actual values and differences in soil water contents may not be indi-
cative of the watershed. All three exclosures were located on the upper ele-
vation of the watershed in order to prevent unknown amounts of actual runoff
from above the exclosures. There may be an optimum amount of aboveground
plant biomass which was maintained or surpassed by grazed areas with more
favorable site conditions. The eight locations indicated in Figure 50 were
all on relatively shallow (i.e., 40 to 50 cm) upland soils. Additional re-
search is needed to determine the vegetation-soil water relationships for
all range sites.
Soil Water Use Rate
The rate of soil water use or loss from the soil due to evapotranspir-
ation is shown in Figure 51. Soil water use rates were calculated as (precip-
itation - runoff - difference in total soil water in succeeding sampling
dates) divided by the number of days between sampling dates. The data used to
calculate soil water use are also presented in Appendix I. Several periods
were combined in order to provide soil water use values significant at the
0.05 level of probability.
The rate of soil water use was related to soil water availability and
vegetation growth. The total precipitation per period and the average soil
water use rate per period are represented by the heights of the appropriate
bars. Total soil water use per period is represented by the area (rate X
number of days) of the bar for each period.
Only in the winter of 1977-78 was there a negative soil water use. Al-
though precipitation insoak in the winter of 1977-78 was only slightly less
than in the winter of 1976-77, the colder temperatures in the second winter
reduced evaporation. Since soil water sampling was not consistent as to
78
-------
UNGRAZED
Locotion No. 8
Soil Water (%)
10 12 14 16 16 20 22 24
- 10
120
S30
S40-
GRAZED
Location No. 9
Soil Water (%)
nO . 10 12 14 16 18 20 22 24
Izo
40
Location No. 26
Soil Water (%)
10 12 14 16 18 20 22 24
_ 10
E
S.30
-------
> 5.0
O
TJ
4.0
3.0
a:
o>
0
"5
tn
2.0
00
O
E
o
O
M
o
"5
o
0>
AMJJASONDJFMAMJJASONDJFMAMJJASOND
1 1976 " 1977 " 1978 '
Figure 51. Soil water use rate (mm/day) 1n relation to precipitation and
insoak (mm).
-------
sampling date or sampling period length, it was not possible to make an exact
comparison between soil water use rates; however, the values shown in Figure
51 are indicative of seasonal soil water use. The maximum values determined
were above 5.0 mm/day in the May - June period in 1977 and in late June -
early July of 1978. No doubt the use rates during some periods of May and
June of 1978 were also greater than 5.0 mm/day.
The high use rate of 4.0 mm/day in March 1978 was greater than expected,
but apparently was the result of warm temperatures and earlier and greater
growth of cool season annual grasses. The negative use rate in April 1978
is-somewhat misleading since soil water sampling occurred soon after an early
April rain added more insoak than was depleted in March. Consequently, soil
water use rate values during isolated short periods can lead to erroneous
interpretations.
In general the soil water use rates shown in Figure 51 appear to be more
realistic measures of evapotranspiration than pan evaporation or any other
parameter that does not consider temperature, available soil water or water
use by the actively growing species present at a particular time in the year.
Soil water content indicates the soil water in the soil, but does not reflect
the rate of evapotranspiration.
VEGETATION
Plant Biomass
The average (K±SE) GROUND LITTER, STANDING DEAD and LIVE herbaceous veg-
etation [kg/ha, oven-dry) on the watershed are shown in Figure 52. Actual
values (X, SE) are shown in Appendix J. GROUND LITTER values were most vari-
able, both within a single sampling date and between sampling dates. In 1976
GROUND LITTER biomass increased to a high.in late summer then decreased during
the winter. Rainstorms in May have caused the significant decrease in GROUND
LITTER in September 1976, November 1977 and February 1978. Although runoff
through the wier was not frequent, intense rain storms of short duration often
moved recently deposited GROUND LITTER on steep slopes and ridgetops down to
lower slopes where it was accumulated. Greater amounts of STANDING vegetation
on the lower slopes acted as a barrier to overland flow of runoff water and
GROUND LITTER. GROUND LITTER was generally least in early spring after winter
decomposition. The relatively low GROUND LITTER biomass in the summer of
1977 was apparently the result of the large amount of runoff (60 mm) and the
dung removal from sampling areas in May 1977. The average GROUND LITTER bio-
mass during the study period was 2070 ± 2270 kg/ha. The standard error of
the mean was 100 kg/ha.
STANDING DEAD biomass was more consistent than GROUND LITTER both within
a single sampling date and between sampling dates. STANDING DEAD biomass
was least in early spring and greatest in early winter. STANDING DEAD biomass
was less in 1977 and 1978 because of reduced LIVE plant biomass in 1976 and
1977, respectively. Reduced plant production and consistent stocking rates
yield a greater grazing pressure and reduced grazing residue. The average
STANDING DEAD biomass during the study period was 1100 ± 850 kg/ha, with a
standard error of 40 kg/ha.
81
-------
2000
0
Live
I II
00
ro
2000
0
o
=3
o
6000
0
Standing Dead
AMJ JASONDJFMAMJJASONDJFMAMJJASOND
I 1976 1 1977 1 1978 1
Figure 52. Average (X±SE) GROUND LITTER, STANDING DEAD and LIVE herbaceous vegetation (kg/ha,
oven-dry) on a tallgrass prairie watershed grazed by cattle in North Central
Oklahoma.
-------
STANDING DEAD plants act as a retardant to overland flow and increase
insoak. Therefore, on grazed watersheds rangeland managers should try to
determine and maintain the optimum amount of STANDING DEAD biomass to mimimize
movement of dung and GROUND LITTER by overland flow. Although plants are
least susceptible to grazing during their dormant season, excessive removal of
STANDING DEAD vegetation increases the likelihood of undecomposed and accum-
ulated dung moving into stream channels. In addition, work by Powell et al.
(1982) shows that absolute minimum temperatures in January, accentuated by
minimum STANDING DEAD and GROUND LITTER mulch, are negatively related to pro-
duction and forage quality.
LIVE plant biomass was less in 1976 and 1977 than in 1978. Peak produc-
tion was 1420 ± 550 kg/ha in mid-June 1976, 1440 ± 460 kg/ha in early June
1977 and 1630 ± 620 kg/ha in mid August 1978. Summer rains in 1977 caused a
second peak production in early September. Summer rains in 1978 maintained
peak production from late June through mid August.
Other scientists report the period of peak production in the tall grass
prairie varies from June to August depending on species composition,, site
factors such as mulch and soil water content, and external factors such as
fire and grazing intensity (Broyles 1978, Conant and Risser 1974, Kelting
1954, Smeins and 01 sen 1970, Tomanek and Albertson 1957). In general produc-
tion peaks later in the summer when tall grasses dominate the stand and when
soil water conditions and grazing intensity permit net assimilation to exceed
abiotic losses and herbivore utilization. Powell et al. (1982) reported that
average maximum temperature in July accounted for about half the variation
in tallgrass prairie production over a 22-year study near Stillwater.
Peak Production
Species Classes
LIVE plant biomass (kg/ha, oven-dry) for different species classes during
the growing seasons of 1976, 1977 and 1978 is shown in Figures 53, 54 and
55, respectively. The list of plant species found on the watershed is pre-
sented in Appendix K. Most plant species exhibit a definite period of maximum
growth and peak production during a growing season. Soil water use is related
to plant growth. Rapid soil water depletion by spring or cool season species
can influence the soil water available for summer or warm season species.
Grazing distribution is also influenced by plant phenology since animals
usually prefer to graze the tissue of rapidly growing plants. When plant
species are site dependent, livestock grazing on different range sites varies
with plant species present and their phonological stage.
The differences in growth patterns for different species classes under
grazing conditions are evident in each of the three figures. Rainfall was
relatively low in 1976 and 1977 compared to that in 1978. Production of tall-
grasses and little bluestem peaked in June 1976 because of limited rainfall
in May and June. .Production of cool season grasses and spring and early sum-
mer forbs peaked in late May. Production of shortgrasses and late summer forbs
peaked in August in response to July rains.
83
-------
400-
300
200
100
0
1978
Lote Summer Forbs
100
0
200
100
0
400
300
200
100-
-Spring Forbs
Cool Season Grasses
Midgrasses
Shortgrasses
Little Bluestem
Apr. May Jun. Jul. Aug. Sep. Oct. Nov.
Figure 53. Dry matter production (kg/ha, oven-dry) of
herbaceous species classes during the 1976
growing season on a tallgrass prairie water-
shed grazed by cattle in North Central
Oklahoma.
84
-------
300-
200-
100-
1977
Late Summer Forbs
Early Summer Forbs
400
300-
200-
100-
Spring Forbs
Cool Season Grasses
Little Bluestem
Apr. May Jun. Jul. Aug. Sep. Oct. Nov.
Figure 54. Dry matter production (kg/ha, oven-dry) of
herbaceous species classes during the 1977
growing season on a tall grass prairie water-
shed grazed by cattle in North Central
Oklahoma.
85
-------
1976
Lote Summer Forbs
200
100
I 0
>*
| 200
"o
1100
ol
0
Cool Season Grasses
Midgrasses
Little Bluestem
Apr. May Jun. Jul. Aug. Sep. Oct.
Nov.
Figure 55. Dry matter production (kg/ha, oven-dry) of
herbaceous species classes during the 1978
growing season on a tallgrass prairie
watershed grazed by cattle in North Central
Oklahoma.
86
-------
In 1977 production peaks for all species classes were somewhat different
than those in 1976. The growth curves for most species classes were generally
flatter than in 1976 with less pronounced peaks. The sharp decline in live
little bluestem biomass between early June and early July is unexplained.
The large amount of growth of leaf material in May may have exceeded the po-
tential of the roots to maintain the water supply during the rapid soil water
depletion in June.. The second peak in little bluestem production in early
August probably reflects a replenishment of surface soil water by late June
and early July rains.
Little bluestem growth in the spring of 1978 was slower than in 1976 or
1977, but peak production was maintained over a longer period and later into
the summer than during the two previous years. The relatively consistent
growth pattern of tall grasses reflects their deeper rooting depths. Produc-
tion of shortgrassess, midgrasses, late summer forbs and little bluestem peak-
ed in mid August at about the time soil water content was lowest. Apparently
the rain in mid June 1978 did much to prolong the growth of warm season spe-
cies. ,
These figures indicate growing conditions have a strong influence on
growth curves of several species classes. Soil water influences plant growth
and plant growth of species with different rooting patterns in turn influences
soil water extraction.
Accumulative Production
Total LIVE rangeland plant biomass produced during a growing season is
nearly always underestimated by sampling at only one time during the growing
season. As discussed before, production for different species classes peaks
at different times during the growing season.
Natural plant degradation and leaching of dry matter occurs even during
the growing season. Therefore total LIVE plus current year's STANDING DEAD
is not always an accurate measure of total growing season production.
Accumulative production or sum-of-the-peaks production is a more accurate
measure of total range plant LIVE biomass production if the vegetation is
composed of more than one species class. In this study, we divided existing
species into eight different species classes. Spring forbs and cool season
grasses could be combined into one species class based only on phenology.
We choose to distinguish the two species classes because cool season grasses
after death persist through the summer as standing dead. Most spring forbs
after death become ground litter more rapidly than do cool season grasses.
In this study, the sum-of-the-peaks production was 24%, 14% and 17%
greater than the greatest single peak production estimate in 1976, 1977 and
1978, respectively. With a more uniform rainfall distribution during the
spring and summer, the difference is expected to be greater. The difference
would also be greater when the range condition is higher because of the
greater diversity of plant species with different phenologies.
87
-------
Another factor to be considered in estimating total plant production on
a grazed watershed is the amount consumed and trampled by grazing animals.
Assuming an average utilization (ingestion plus trampling) figure of 12 kg
dry matter per animal-unit-day from May through July and using the stocking
density figures calculated, dry matter disappearance due to grazing was 410
kg/ha May through July, 1976, 400 kg/ha May through July, 1977 and 350 kg/ha
May through September, 1978. These figures represent 30%, 30%,"and 22% of
the greatest peak LIVE biomass in 1976, 1977 and 1978, respectively. These
exact amounts should not be added to accumulative production because part of
the material utilized later in the summer was no doubt a part of the peak
production contributed by species classes with early peak production. Utili-
zation or dry matter disappearance due to grazing will be discussed in greater
detail in the section of the report concerning utilization. In general, how-
ever, the addition of 30% to 50% greater production than shown in Figures
53, 54, and 55 would be valid when considering the relationships between plant
production and soil water use.
Range Sites
Differences in plant species class biomass (kg/ha), composition (%) and
selected site factors on loamy prairie and shallow prairie range sites are
shown in Table 18. LIVE, STANDING DEAD and GROUND LITTER biomass were all
greater on loamy prairie sites than on shallow prairie sites. Loamy prairie
sites included the deeper soils which generally occurred at the lower slope
positions, whereas shallow prairie sites included the soils on the upper
slopes. Tall grasses, little bluestem, late summer forbs and shrubs are all
relatively deep-rooted and were more abundant on the deeper soils.
Grasses were of about the same proportion of total LIVE vegetation on
both sites, but forbs comprised a higher proportion of LIVE vegetation on
the shallow prairie sites. Shortgrasses were also much more abundant on shal-
low prairie sites.
Ground cover and A horizon soil water content were greater on the loamy
prairie range sites. Surface soil temperature was greater on the shallow
prairie range sites.
The claypan prairie, shallow savannah and sandy savannah range sites
were not sampled with enough locations to warrant statistical comparisons.
These three range sites occupied only 15% of the watershed, whereas loamy
prairie range sites occupied 53% and shallow prairie 32% of the watershed.
From a watershed and livestock grazing management standpoint, a range
site is a practical and fundamental unit of management. Site conditions in-
fluence plant production, species composition and, frequently, plant palata-
bility. Consequently, range site conditions influence grazing preference.
Grazing preference, in turn, can accentuate differences in site conditions,
such as ground cover and species composition. An understanding of range site-
grazing preference relationships is, therefore, essential if a watershed
scientist is to accurately predict or effectively manipulate the effects of
livestock grazing on runoff quantity and quality.
-------
TABLE 18. PLANT SPECIES CLASS BIOMASS (KG/HA), COMPOSITION (X) AND
SELECTED SITE FACTORS ON LOAMY AND SHALLOW PRAIRIE RANGE
SITES ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY CATTLE IN
NORTH CENTRAL OKLAHOMA, 1976-78
Biomass(kq/ha)
Species
Class
(19 Sampling Dates)
LIVE
GRASSES
Tall
scsc
Mid
Short
Cool
Other
FORBS
Spring
Early Summer
Late Summer
SHRUBS
LIVE (35)
(31 Sampling Dates)
Ranqe Site
Loamy
1205
770
215
275
170
30
45
40
335
40
105
190
100
Shallow
965
575
65
160
160
90
40
55 .
350
60
130
160
35
^/
*
*
*
*
0.63
*
0.88
*
0.54
*
0.13
0.07
*
Composition (%)
Ranqe Site
Loamy
64.7
16.4
22.7
14.4
3.2
4.4
3.8
29.5
4.7
9.1
15.8
5.9
49.7
Shallow
63.2
6.5
16.2
18.3
10.8
5.4
6.0
35.1
6.6
12.2
16.4
1.9
56.2
P
0.25
*
*
*
*
0.17
*
*
*
*
0.54
*
*
.STANDING DEAD 1295 760 *
GROUND LITTER 1925^-/ 1485^ *
ABOVEGROUND ,,
PHYTOMASS-^ 4410 3210 *
GROUND COVER (X) 89.1 80.7 *
SOIL WATER
(A horizon) (X)
SOIL TEMP. (C)
9.2
23.4
8.0
25.4
0.08
*
E Probability level ( * = P 0.05).
gy Includes dung on first four sampling dates,
T// Includes dung on all sampling dates.
-' LIVE + DEAD + GROUND LITTER.
89
-------
Grazing Effects
The average LIVE and STANDING DEAD plant biomass (kg/ha, oven-dry) in-
side (ungrazed) and outside (grazed) three, 0.5 ha cattle exclosures during
the study period is shown in Figure 56. In general growth patterns for LIVE
vegetation inside and outside the exclosures were similar. Therefore, al-
though grazing reduced the amount of LIVE vegetation, residue grazing did
not significantly alter the growth pattern or period of peak standing produc-
tion except during the dry summer period in 1976. At this time grazing tended
to flatten the growth curve.
Differences between ungrazed and grazed STANDING DEAD litter were smaller
in 1976, the first year exclosures were in effect, than in the two following
years. STANDING DEAD litter biomass in any year is largely the result of
the previous year's production and to a lesser extent, the current year's
DEAD from cool season annual grasses and forbs.
The sharp increase of STANDING DEAD in the fall of 1976 and gradual de-
cline until late summer of 1977 was similar inside and outside the exclosures.
Differences in STANDING DEAD were greatest in 1978 and probably reflects the
beginning of significant accumulated effects of grazing.
The utilization study determined that cattle consumed a significant
amount of STANDING DEAD during all seasons. The average STANDING DEAD in
the diet was about 55% during the 30-month sampling period and exceeded 20%
even during the growing season when LIVE forage was relatively abundant.
The STANDING DEAD was reduced to its lowest amount in March, 1978 out-
side the exclosures and only gradually increased during the growing season.
This was in contrast to the rapid decline in STANDING DEAD in ungrazed areas
between March and late June and the rapid increase between late June and the
fall. Apparently natural weather conditions converted much of the ungrazed
STANDING DEAD to GROUND LITTER in the spring of 1978. The rapid increase in
ungrazed STANDING DEAD after June indicates the death of many plants and plant
parts when plants mature or conditions become less favorable for growth.
Differences in average species class biomass (kg/ha) and composition in
ungrazed and adjacent grazed areas is shown in Table 19. Because of the large
number of sampling periods (i.e., 19 during the growing season and 12 during
the dormant season) and the accumulative effects of grazing, most of the dif-
ferences were significant at the 0.05 or less level. Shortgrasses maintained
production under relatively xeric conditions on the upper slopes where the
exclosures were located. Grazing pressure near one of the exclosures was
heavy and shortgrasses are more resistant to heavy grazing pressure than most
other species in the tallgrass prairie. Spring forbs and "other" grasses
were also as abundant on grazed areas as inside the exclosures. Warmer soils
on grazed areas in the spring increased spring forb production. Many of the
"other" grases were less palatable, "increaser" species.
The changes in percent composition shows that grazing on the upper slopes
'tends to reduce tallgrasses and little bluestem and increase those species
which are more resistant to grazing due to morphological characteristics or
90
-------
4000
2000
o
o
0
Dead
us
2000
0
Live
j_
Is
s
\
N \
AMJJASONDJ FMAMJJASONDJFMAMJJASOND
I 1976 1 1977 1 1978
Figure 56. Average LIVE and STANDING DEAD plant biomass (kg//ha, oven-dry) inside
(ungrazed) and outside (grazed) three, 0.5-ha exclosures on a
tall grass prairie watershed grazed by cattle in North Central
Oklahoma.
-------
UJ
ro
TABLE 19. COMPARISON OF AVERAGE (3 PAIRED SAMPLES) PLANT SPECIES CLASS BIOMASS (KG/HA, OVEN-DRY),
COMPOSITION (%), AND SELECTED OTHER FACTORS INSIDE (UNGRAZED) AND OUTSIDE (GRAZED) THREE,
0.5 HA EXCLOSURES ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY CATTLE IN NORTH CENTRAL
OKLAHOMA, 1976-78
Biomass (kg/ha)
Species Class
(19 Sampling Dates)
TOTAL LIVE
GRASSES
Tall
Little bluestem
Mid
Short
Cool Season
Other
FORBS
Spring
Early Summer
Late Summer
SHRUBS
% LIVE
(31 Sampling Dates)
STANDING DEAD
GROUND LITTER
ABOVEGROUND,-,
PHYTOMASS2/
GROUND COVER (%)
SOIL WATER (%, A Horizon)
SOIL TEMP. (C)
Ungr.
1480
1020
225
420
235
55
55
25
450
45
225
185
10
2390,,
2040^
5620
96.2
11.1
17.9
Grazed
1030
660
100
220
190
85
30
40
345
45
165
130
25
1190
1750^/
3520
86.0
10.7
19.9
Diff.-7
-450
-360
-125
-200
-45
+30
-15
+15
-105
0
-60
-55
+15
-1200
-290
-2100
-10.2
-0.4
+2.0
pi/
0.01
0.01
0.01
0.01
0.20
0.15
0.04
0.04
0.05
0.75
0.18
0.04
0.08
0.01
0.16
0.01
0.01
0.71
0.18
Ungr.
70.0
14.0
28.5
17.2
4.1
4.6
1.9
29.3
3.8
13.8
11.9
0.7
43.9
Composition (%)
Grazed
64.8
9.1
21.3
17.9
8.7
3.4
4.4
32.9
5.7
13.7
13.6
2.3
52.5
Diff.
-5.2
-4.9
-7.2
+0.7
+4.6
-1.2
+2.5
+3.6
+1.9
-0.1
+1.7
+1.6
+8.6
P
0.04
0.01
0.01
0.66
0.01
0.28
0.01
0.15
0.12
0.97
0.24
0.05
0.01
jyGrazed - Ungrazed.
r/Includes dung on first four sampling dates,
^LIVE + STANDING DEAD + GROUND LITTER.
^Probability level.
Includes dung on all sampling dates.
-------
lower palatability. Many of the late summer forbs were low in palatability.
The greater biomass and percent composition of shrubs outside exclosures was
contradictory to what was observed. Most of the plants of shrub species were
observed to be grazed near the exclosures. Certain species, such as Ulmus
americana, definitely showed a hedged effect (Figure 57), and other shrub
species, such as Rhus spp., normally considered to be unpalatable, showed
evidence of browsing.
Figure 57. Effect on browsing on shrubs outside
exclosure.
Differences in GROUND LITTER were small because all dung was removed
from within exclosures in the summer of 1976. Therefore although herbaceous
GROUND LITTER was much less outside exclosures, the dung deposited in grazed
areas increased the total GROUND LITTER recorded. Including dung in the total
GROUND LITTER is a realistic assessment of energy flow and nutrient cycling
since much of the forage consumed by grazing animals passes through the ani-
mals and remains on the watershed.
Ground cover was reduced by grazing on the upper slopes and more bare
ground provided greater opportunity for establishment of cool season annual
grasses and other species of a lower successional level. Reduced ground cover
also increases the effect of raindrop splash and soil particle displacement.
Because of concentrated grazing on soils of the upper slopes where the exclo-
sures were located, the ground cover value shown in Table 19 was much less
than the average over the whole watershed.
Soil water content in the A horizon was similar in the grazed and ungrazed
areas. This does not reflect the differences in total soil water. Greater
root biomass (inferred from greater live vegetation biomass) in ungrazed
areas would cause greater transpiration loss. However, greater ground cover
in ungrazed grass would conversely reduce evaporation loss. Infiltration
93
-------
rates were not determined and such data would help to interpret the soil water
budget in the different areas.
It should be pointed out that the values for TOTAL LIVE in Table 19 re-
flect the average LIVE y/egetation at a point in ttme. These values do not
reflect total vegetation produced in the grazed areas. The utilization study
using small cages in the grazed locations near the exclosures showed that an
average of 425 kg/ha was removed by grazing animals. Therefore, adding the
amount of LIVE vegetation utilized (425 kg/ha) to the average LIVE grazing
residue (1030 kg/ha) indicates total production (1455 kg/ha) on grazed areas
near the exclosures was about the same as that (1480 kg/ha) in ungrazed areas.
Since the tallgrass prairie evolved under grazing, it should not be unexpected
that properly grazed areas are as productive as ungrazed areas.
Soil temperature values in grazed areas averaged 2.0 C higher than in
ungrazed areas, but the magnitude of differences was not consistent (P 0.18).
Differences appeared to be related to grazing pressure. Grazed area temper-
atures were 0.6 C, 1.5 C and 2.6 C higher on the light, moderate and heavy
grazed areas, respectively. Those areas with the greatest differences in
ground cover and standing vegetation had the greatest differences in soil
temperatures.
Site Factors, Species Frequency and Biomass
Species Frequency (Late Winter, 1976)
Slope length varied from 82 to 158 m and slope percent ranged from 1 to
7% for the 20 transects. Although the same major species were found on all
slope positions indicating that many common species have a broad ecological
amplitude, their frequency of occurrence varied by slope position, aspect,
and soil type.
Slope positionThe number of grass species found on different slope
positions was similar; however, desirable tallgrasses (Andropogon gerardi.
Sorqhastrum nutans, and Panicum virgatum) were least common on upper slope
positions (Table 20). Tallgrasses were three times more common on lower
slopes than upper slopes. Sorghastrum nutans (SONU) was twice as common as
Andropogon qerardi (AN6E) on lower and mid slopes, but all three desirable
tallgrasses had similar frequencies on upper slope positions. Andropogon
virginicus (ANVI) was found in 10% of the lower slope plots and was most com-
mon on the deeper soils.
Schizachyrium scoparium (SCSC), the most common species, occurred at
86% of all sampling locations. SCSC and Panicum oliqosanthes (PAOL) were
found more frequently on lower slopes and least frequently on upper slopes
(Table 20). However, SCSC was present in 7358 of the upper slope plots while
PAOL frequency decreased to 38% in upper slope plots. The third midgrass,
Bouteloua curtipendula (BOCU), was similar to shortgrasses in frequency on
slope positions and changed little in relation to slope position. Carex spp.
were present in about half of the quadrats sampled but Carex frequency did
not change with slope position.
94
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TABLE 20. FREQUENCY OF OCCURRENCE (%) FOR SELECTED SPECIES AND
SPECIES CLASSES ON DIFFERENT SLOPE POSITIONS
Species Class
and Species
Slope Position
Lower
Mid
Upper
Prob.-
6RASSES
Tall grasses ^i
Desirable tall grasses-' 63
Andropogon gerardi 21
Panicum virgatum 19
Sorghastrum nutans 45
Andropogon virginicus 10
Midgrasses
Schizachyrium scoparium 98
Panicum oligosanthes 77
Boute'loua curtipendula 33
Carex spp. 50
Shortgrasses
Bouteloua hirsuta 14
Bouteloua gracilis 8
Aristida oligantha 43
Aristida spp. (perennial) 12
FORBS
49
13
22
21
3
87
54
50
43
31
18
42
14
19
7
7
8
0
73
38
58
41
46
23
68
13
0.01
0.12
0.21
0.01
0.19
0.07
0.01
0.14
0.68
0.03
0.10
0.06
0.91
Ambrosia psilostachya
Artemisia ludoviciana
Xanthocephalum
dracunculoides
Diversity Index^/
65
20
,10
7
57
4
30
7
63
6
36
7
0.86
0.01
0.05
0.78
-/Probability that differences in frequency of species among slope
positions are due to chance.
-/These species are the most desirable for livestock grazing and
include only Andropogon gerardi, Panicum virgatum, Sorghastrum
nutans.
-^Average number of different species in sampling locations at each
slope position.
95
-------
Shortgrasses were nearly as abundant on upper slopes as tall grasses were
on lower slopes. Frequency of Bouteloua hirsuta (BOHI) was nearly twice that
of Bouteloua gracllls (B06R) on all slope positions. BOHI and BuGR were both
more abundant on upper slopes than on lower slopes. Aristiaa ollqantha (AROL)
was also more common on upper slopes which had more xeric soils ana more pi ant
disturbance (e.g., consumption of herbage and animal trampling). Uther Aris-
tida species (Aristida lonqiseta. A. purpurascens) were not common at any
slope position.
The average number of forb species per quadrat was the same at all slope
positions. Ambrosia psilostachya (AMPb), the most common forb, was affected
very little by slope position. In general Artemisia ludoviciana (ARLu) was
associated with tallgrasses and deeper soils. Xanthocepnalum dracuncuioides
(xADR) was frequently found in areas disturbed by grazing, and was three times
more abundant on mid and upper slopes than on lower slopes, ihe frequency of
occurrence of XADR was inverse to that of ARLU.
A species diversity index indicated that there was no difference 1n the
number of species found in samples along slope positions although species
composition was diverse. STANDING LITTER, TOTAL LITTER (STANDING and GROUND)
and STANDING LITTER to GROUND LITTER ratio were highest on lower slope posi-
tions where tail grasses were more abundant and lowest on upper slope positions
(Figure 5a). : .
l,200r
1,000
I
800
600
400
200
STANDING
GROUND
LOWER MID UPPER
SLOPE POSITION
Figure b8. Average standing, ground, and total litter
phytomass (kg/ha, oven-dry) on the three
slope positions. LSD ni- (standing) = 210
Kg/ha; LSD n(- (ground)"* 200 kg/ha; LSD -
(total) = 360 kg/ha.
-------
The occurrence of certain species can be related to total available water
in the sol urn. Tall grass species require a greater amount of water than short-
grasses for maximum growth and would be at a disadvantage on soil types with
a limited available soil water supply. Deeper soils on the watershed con-
tained a greater available soil water storage area (Powell et al. 1978, Powell
et al. 1979).
In the tallgrass prairie Bouteloua species are normally associated with
areas where available soil water is a major limiting factor (Anderson and
Fly 1955). In this study, Bouteloua species were more competitive on soils
and under grazing conditions commonly found on upper slope positions. BOCU
was less frequent on lower slopes due to its inability to compete with the
tallgrasses in their normal habitat. On this watershed BOHI was more abundant
than BOGR, while in western Oklahoma, B06R would be more common than BOHI on
upper slopes and shallow soils (Clements 1920).
AROL is an indicator of overgrazing, poor soil management, or other dis-
turbances (Booth 1941, Weaver 1968). Trampling and heavy grazing by animals
on upper slope locations resulted in reduced ground cover and exposed soil
which may have allowed opportunistic species, such as AROL, the chance to
become established. Animal behavior and preference patterns often create
such areas by overgrazing and patchy grazing (Marshall 1974, Heady 1975).
Overgrazing and trampling also appeared to be the reasons for the in-
creased occurrence of XADR on mid and upper slopes. ARLU apparently is com-
petitive under the more favorable soil water conditions associated with deep
soils and was most frequently associated with the tallgrasses. ARLU is a
perennial and is normally found in the "climax" tallgrass community while
XADR is an annual and not considered a part of the "climax" community as de-
fined by USDA Soil Conservation Service range condition guides. Therefore,
soil water appears to be a major factor in the occurrence of ARLU while dis-
turbance of the soil surface by overgrazing affects the occurrence of XADR.
Most of the species mentioned are at least somewhat palatable to cattle
during one or more seasons, and a plant's abundance can certainly be changed
by grazing at different times of the year. Cattle selectively graze areas
and plants of greater nutrient value, even when herbage is not actively grow-
ing (Baker and Powell, IN PRESS). Palatability, preference, and utilization
are related, but relationships may vary due to animal factors, such as differ-
ences in individuals, stage of growth of individual, and social influences
from other individuals, and plant factors, such as stage of plant development
and competition among plants iTribe i95z).
STANDING LITTER is a function of total herbage produced on a site.
Therefore, if grazing pressure and herbage removal remain equal on all sites,
areas with the greater herbage production will have a greater standing litter
crop during the dormant season. In this study the areas with greater STANDING
LITTER grazing residue were the areas with the greatest percentage of tall-
grasses present. Due to cattle preference, these areas were grazed less dur-
ing winter than areas dominated by Bouteloua species. Animal preference
97
-------
factors could lead to over-utilization of a range site during any time of year
if animal grazing-vegetation-site relations are not understood or considered.
AspectThe compass bearing sectors for north-, east-, south-, and west-
facing slopes were 316-45°, 46-135°, 136-225°, and 226-315°, respectively.
The AOV for aspect used only the desirable tall grass species and midgrass,
shortgrass, and forb species listed in Table 20. These species accounted
for about 95% of the species present in the samples. The effect of aspect
on vegetation occurrence and frequency was similar for all grass species.
Species frequencies were greater on north and east slopes than on south and
west slopes. Because probability values for no grass or forb species class
were less than 0.20, the discussion is based only on trends.
Midgrasses had the highest frequency because of the abundance of SCSC.
Frequencies of all grass species were greater on northern and eastern expo-
sures than on southern and western exposures (Figure 59). Short-, mid- and
tallgrasses frequencies were similar on north and east slopes and on south
and west slopes. Tall- and shortgrass frequencies were 20-25% less on west
slopes than on north slopes. The decrease in tallgrasses was more evident
for AN6E and PAVI than for SONU. Forb frequencies were inverse to that of
short-, mid-, and tallgrass frequencies. Forbs were 11% more abundant on
south and west slopes than on north slopes and 21% more abundant on the south
and west slopes than on east slopes. Most differences in frequency of forbs
resulted from differences in frequency of occurrence of AMPS and XADR.
100
90
80
"
i
DESIRABLE TALLGRASSES
MIOGRASSES
SHORTGRASSES
FORBS
N E S W
315-44 43-134 139-224 229-314
ASPECT
Figure 59. Frequency (%) of species
classes by aspect,
February 1976.
In the northern hemisphere, south slopes receive more solar insolation
per unit area than north slopes. Southwest slopes are usually warmer than
98
-------
southeast slopes since direct sun occurs on southeast slopes shortly after
periods of night cooling when dew evaporation also may delay warming (Chang
1968). Microclimatic differences cause differences in plant communities and
species frequencies. Soil water losses caused by evaporation are greater on
south and west slopes than on north and east slopes and create more xeric
conditions. Air temperatures are often independent of aspect (Sartz 1972)
but in this area evaporation on south and west slopes is increased by expo-
sure to hot, dry southwest winds in the summer.
In the watershed study area, there were two to three times as many grass
species as forb species. The trend toward lower frequencies of different
grass species classes on south and west slopes indicated a lower number of
grass plants, in general, and increased bare ground. Many of the forb spe-
cies found on the more xeric and overgrazed slopes were relatively unpalat-
able and opportunistic. Annual grasses were also more common on south and
west slopes, based on observation, but were not included with the perennial
grasses. In general, those grass and forb species established by seed were
most common in the areas with the higher percentage of bare ground.
Species changes in plant communities are common when comparing aspects
within small watersheds (Zavesky 1967). During the data analysis we found
that analysis of variance was not adequate for determining the desired influ-
ence of aspect. We had taken a continuous variable (aspect) and artificially
divided it into classes containing a series of transects in a 90° arc, rather
than transects from a midpoint aspect allowing a blending of the vegetation
between aspect classes. Probability values from the AOV are similar if only
N vs S, E vs W, or N, E, S, W transect differences were tested. The small
scale of the watershed may also have influenced differences due to aspect so
they were not as distinct as those of other regions (Smith 1977).
Soil TypesTall grass frequency increased as A horizon thickness in-
creased (Table 21). All four tall grass species were more common on the deeper
Stoneburg and Zaneis soils than on the shallower Darnell and Lucien soils.
Soil depth appeared to make less difference in midgrass frequency except on
the Darnell where the frequency of each species, except Carex species, was
considerably less. Shortgrass frequency was much less on the Darnell and
equal on the other soils. Paspalum and Bromus spp. were the major species
present on the Darnell soil type. AROL was most frequent on the Lucien and
Zaneis. Forbs were least frequent on the Lucien type and nearly equal on
the other soils. AMPS was most common on the Darnell and Grainola soils.
A horizon thickness and solum depth are directly correlated. Deeper
soils'normally have a greater water storage capacity, and unless some factor,
such as texture, limits water availability, tall grasses will be most common
on deeper soils. The shallow, fine sandy loam Darnell soil supported few
grass species while the Lucien, which is similar in depth and loamy-textured,
supported more grass species. Darnell soils supported scattered Quercus spp.
and Junipenis spp. trees which probably removed much available water from
the entire solum while the Lucien supported only herbaceous species. Soil
water conditions were favorable for mid- and shortgrasses on all soils except
Darnell soils. The shallowness of the Lucien type and the shallow depth to
the thick argillic horizon of the Grainola limited available soil water and
99
-------
TABLE 21. FREQUENCY OF OCCURRENCE (%) FOR SELECTED SPECIES AND SPECIES CLASSES ON DIFFERENT
SOIL TYPES
o
o
Species Class
and Species
GRASSES
Tall grasses 2/
Desirable tallgrasses-'
Andropogon gerardi
Pan 1 cum vlrgatum
Sorghastrum nutans
Andropogon vlrglm'cus
Midgrasses
Schizachyrlum scoparlum
Pam'cum oligosanthes
Bouteloua curtipendula
Carex spp.
Shortgrasses
Bouteloua hlrsuta
Bouteloua gracilis
Arlstlda ollgantha
Aristida spp. (perennial)
FORBS
Ambrosia psilostachya
Artemisia ludoviciana
Xanthocephalum dracunculoides
Soils
Darnel 1
4
0
4
0
0
8
17
0
50
0
4
13
8
88
25
17
Grainola
30
13
11
11
0
84
50
60
40
25
14
54
11
71
8
49
Lucien
33
5
14
19
1
90
60
62
38
44
23
63
18
58
13
19
Stoneburg
63
23
18
42
6
97
50
37
50
31
15
38
11
47
30
28
Zaneis
84
25
34
59
25
94
69
22
56
13
9
69
9
47
9
9
Prob.^/
0.01
0.04
0.50
0.01
0.03
0.01
0.13
0.01
0.72
0.18
0.57
,0.07
0.67
0.14
0.28
0.12
Probability that differences in frequency of species among soil types are due to chance.
-/Includes only Andropogon gerardi, Panicum vlrgatum, Sorghastrum nutans.
-------
reduced tall grass frequency. Competition for soil water between woody and
herbaceous species is not often considered in Central Oklahoma rangelands.
However, in this instance Darnell soils provided conditions conducive to tree
growth resulting in more droughty conditions and competition for light for
herbaceous plants.
Length and orientation of slopes and position on slopes correlate with
the distribution (frequency) of many plant species on rangeland. Several
environmental factors, such as soil water, soil type, and evaporation rate,
are influenced by slope. The tallgrass prairie community is a stable commun-
ity that shows the effects of differences in slope position, aspect, and soils.
Most species were found to be adaptable enough to exist under the entire range
of conditions. In this study tall- and midgrass species varied in frequency
more with aspect on lower slope positions while frequency of short- and some
midgrass species varied more on upper slope positions. All grass species
classes responded similarly to increasing soil depth and north and east versus
south and west aspects. The abundance of forbs was related more to soils
and aspect than to slope position. Darnell soils were illustrative of soils
that could support a savannah, but not the diverse herbaceous community as
might be expected in the area.
Rangeland management is directly related to the grazing animal, and the
grazing animal must be considered an integral part of the rangeland ecosys-
tem. Animals, as well as plants, are influenced by slope position, soil
types, and aspect. Each factor affects watering locations and resting areas,
and provides for different areas for grazing as seasons change. Rangeland
and management relies on knowing how to manipulate changes in the plant com-
munity by regulating grazing distribution and grazing pressure. A knowledge
of plant species, soils, and physiographic sites is necessary to develop an
effective grazing plan to increase animal distribution at different periods
of the year to utilize more fully the production potential of the rangeland.
Grazing pressureDifferences in species frequency of occurrence due to
slope position were much more evident in the moderately grazed pasture than
in the lightly grazed pasture. SCSC and ANGE were more abundant on lower
slopes than on upper slopes in the moderate area, but the opposite trend ex-
isted in the light area (Figure 60). Apparently these two species are adapt-
ed and competitive on upper slopes under light grazing, but not under heavier
grazing. SONU, PAOL PAVI and ARLU also exhibited significant decreases in
abundance as slope position increased. These decreases were not evident on
the light area. Most of these species are relatively palatable during some
season and decreased due to grazing pressure.
Several minor species increased in abundance with increased slope posi-
tion on both the light and moderate areas (Figure 61). These included AROL,
BOCU, BOHI, BOGR, Solidago (SOLI) spp. and XADR. Although AROL is generally
considered to be an invader, it was more abundant in the light area at all
slope positions than in the moderate area. BOCU was the most abundant
Bouteloua species, but BOHI and BOGR exhibited relatively greater differences
between frequencies on lower and upper slopes than did BOCU.
101
-------
LIGHT
MODERATE
ARLU
SLOPE
POSITION
- UPPER
- MIDDLE
- LOWER
scsc
J I
IOO 80 60 40 20 0 20 40 60 80 100
FREQUENCY (%)
Figure 60. Frequency of dominant species in relation
to slope position and grazing pressure,
February 1976.
102
-------
LIGHT
MODERATE
BOCU
SLOPE
POSITION
- UPPER
- MIDDLE
- LOWER
I I I
100 80 60 40 20 0 20 40 60 80 100
FREQUENCY (%)
Figure 61. Frequency (%) of lower successional
species in relation to slope position
and grazing pressure, February 1976.
103
-------
SOLI was generally more abundant on the upper slopes, but the differences
were not consistent. GUDR is commonly found on dtsturbed soil and was much
more abundant on closely grazed middle and upper slopes In the moderate area
than in the light area or on lower slopes in the moderate area. Other species,
such as Carex and Sporobolus spp., were relatively abundant, but showed no
preference or trend concerning slope position. AMPS was equally abundant with
an average of 62% frequency on all slope positions in the moderate area, but
its frequency of occurrence was 80% on middle slopes and about 35% on both the
upper and lower slopes in the light area. AMPS frequency was directly corre-
lated with soil potassium content. Both soil potassium and AMPS frequencey
were significantly greater on the light area, middle slopes. Soil potassium
levels were highest on the upper slopes in the moderate area and the strength
of correlation between AMPS frequency and soil potassium levels was also
greatest on the upper slopes. Other species also demonstrated what are appar-
ently curvilinear relationships with various soil and site factors. Addition-
al range ecological research concerning plant species-site factor relations
would be valuable for predicting species responses to range improvement prac-
tices, such as fertilization or burning.
BiomassBiomass values for STANDING DEAD, and for GROUND LITTER on
lightly grazed areas were about twice as great as on the moderately grazed
area (Figure 62). The average total biomass was 2130 kg/ha on the lightly
grazed area and 1000 kg/ha on the moderately grazed area. These values are
very low compared to those reported in the literature for tallgrass prairie.
However, several preceding years of below average precipitation and almost a
complete winter grazing period prior to sampling reduced total biomass to an
unusually low level.
GROUND LITTER yields were very similar on different slope positions in
the moderate grazed area, but greater on the lower slopes of the lightly
grazed area than on the upper and middle slopes.
Differences in STANDING DEAD due to slope position were consistent in
both the light and moderate area; however, on a percentage basis, differences
in STANDING DEAD was much greater on the moderate area. STANDING DEAD on the
upper slopes was only 240 kg/ha, whereas the upper slope position on the
light areas produced 900 kg/ha. The ratio of STANDING LITTER to GROUND
LITTER was also very different on the two areas. This ratio was about 1.0 at.
all slope positions in the light area, but decreased from 0.97 at the lower
position to 0.55 at the upper position in the moderate area. Either herbage
production was very limited at the upper position in the moderate area in the
1975 growing season or else cattle were concentrating their fall and winter
grazing on the ridges and upper slopes.
In general the biomass yields in samples from the light area were much
more uniform that those from the moderate area. Coefficients of variation for
STANDING DEAD and GROUND LITTER biomass on the light area were about half as
large as those for the moderate area. The correlation between STANDING DEAD
biomass and GROUND LITTER biomass was also much higher on the light area than
on the moderate area. However, within the moderate area the correlation was
much higher on the lower slope than on the middle or upper slope position.
More spot grazing, trampling and disintegrated dung pats probably contributed
to the greater variation on middle and upper slopes.
104
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SLOPE
POSITION
-UPPER
- MIDDLE
- LOWER
LIGHT
MODERATE
STANDING DEAD
GROUND LITTER
J 1
I I
16 14 12 10 8 6 42 02 4 6 8 10 12 14 16
BIOMASS (KG/HA X 100)
Figure 62. STANDING DEAD and GROUND LITTER biomass
(kg/ha) in relation to slope position
and grazing pressure, February 1976.
105
-------
Part of the difference in species abundance at different slope positions
or lack of difference in the light area may have been due to differences in
site conditions in the two areas. This will need to be determined using rep-
licated areas with similar conditions. A comparison of the average site fac-
tors on the two areas indicated that factors related to soil water were some-
what more favorable on the light area. These factors included aspect, slope
soil depth, bulk density and organic matter. How much of a difference in
these factors is necessary to cause a measurable difference in species growth
and species interrelationships is not well understood.
Site Factor Regression Equations (Late Winter, 1976)
Regression equations for frequencies of six species, and STANDING DEAD
and total biomass were derived using all data from the light area. Regres-
sion equations which accounted for a significant portion of the variation in
each of the eight dependent variables were derived. R2 values ranged from
60% for BOHI and STANDING DEAD to 93% for SCSC. The individual equations
will not be discussed, but some generalities pertaining to all the equations
can be made. STANDING DEAD and GROUND LITTER biomass values were related
primarily to factors concerning effective soil water. Some of these were
actual soil water content, A horizon thickness, soil depth, slope length and
a Moisture Economy Index. This index was derived by multiplying percent slope
by aspect. Aspect was mathematically adjusted to provide a minimum value of
-1.0 for southwest-facing slopes up to a maximum of +1.0 for northeastern
facing slopes. Independent variables used to predict frequencies of different
species were quite variable. This was because of the wide differences in
requirements and tolerances by the six species.
The derivation of a similar set of equations for the six species and
two biomass variables was also attempted in the moderate area, using values
from all 45 sampling area observations. This attempt was unsuccessful because
site preference and grazing effects by cattle on species created differences
in species frequencies that could not be predicted using only edaphic and
topographic factors.
However, when the 45 observations were sorted by slope position, signif-
icant regression equations were derived for most of the eight variables at
all three slope positions. STANDING DEAD biomass was the most difficult de-
pendent variable to predict. A comparison of the total number of times an
independent variable was mathematically chosen for one of the equations showed
that bulk density, soil phosphorus, calcium and organic matter contents, pH,
soil water and percent slope were chosen most frequently. These had the
widest latitude in predicting species frequencies. Simple linear correlation
analyses were used to determine species associations at the three slope posi-
tions in the moderate area. We found that slope position greatly affected the
direction and degree of association between two species. Some examples of
these effects included 1) SCSC was inversely related to tallgrasses, BOHI,
AROL and GUDR on lower slopes, but directly related to the same species on
upper slopes; 2) SCSC was directly related to AMPS, CARX and SPOR on lower
slopes, but inversely related to these species on upper slopes; 3) The
106
-------
relationship between BOHI and BOCU was stronger as slope position increased,
but the relationship between BOHI and B06R was weaker as slope position
increased; and 4) Of the relationships tested, 18 were significant on the
upper slopes, but only seven were significant at the lower slopes.
Litter Chemical Composition (Late Winter, 1976)Nitrogen, calcium and
phosphorus contents in late winter STANDING DEAD and GROUND LITTER increased
consistently from the lower slopes to the upper slopes on the moderate area
(Figure 63). All differences due to slope position were significant at the
0.10 or less level except for phosphorus content in standing dead. The dif-
ferences between phosphorus content at the lower and middle positions and
that at the upper position was significant at the 0.24 level. Differences
in nitrogen, phosphorus and calcium contents due to slope position in the
light area were relatively small, not consistent, and none were significant
at less than the 0.30 level.
All of the differences in biomass chemical contents on the moderate area
were closely associated with differences in species frequencies. In general
standing dead and ground litter nitrogen, phosphorus and calcium contents
were low where AROL, SCSC and tallgrass species, such as AN6E, PAVI, and SONU,
were abundant. These correlations were much stronger on the upper slopes
than on the lower slopes. Biomass chemical contents were often directly cor-
related with frequencies of various forbs, such as AMPS and SOIL and various
species of the Paspa!urn, Carex and Sporpbolus genera. Many of these species
had green leaves or winter rosettes. These were more accessible to cattle
on the upper slopes and ridges where protective ground cover was less.
Plant chemical contents were also closely associated with each other
whether in STANDING DEAD or in GROUND LITTER. However, the degree of assoc-
iation varied with the particular chemical and plant species composition in
the biomass. Nitrogen and calcium were generally more closely associated
with each other in either STANDING DEAD or GROUND LITTER than with phosphorus.
This is the reverse of what usually occurs in live vegetation.
Plant chemical contents were closely associated with various soil chem-
ical components, but these relationships were not consistent for all slope
positions, plant components or kinds of biomass. Generally, plant chemical
contents were higher on soils with a higher pH and potassium content and -lower
on soils with higher nitrogen and phosphorus contents. Because of the inter-
actions of nutrient uptake and retention by different plants and the differ-
ence in species composition in our samples, we probably do not have enough
samples or an adequate measure of species composition to accurately determine
the relationships between dormant biomass chemical composition and soil chem-
ical composition.
In conclusion we believe that cattle do prefer more xeric sites for late
season grazing and their concentrated grazing on these sites helps to provide
forage of a higher qualtiy than would be available under light grazing or on
more mesic sites. To prevent excessive grazing and provide the maximum forage,
a range manager could defer these areas from heavy grazing early in the summer
by fencing along site boundaries where practical or by using grazing distri-
bution practices to lead livestock away from these sites until later in the
107
-------
SLOPE
POSITION
- UPPER
LIGHT
LITTER
P(%XO.I)
DEAD
P(%XO.I)
LITTER
CA (%)
DEAD
CA (%)
GROUND
LITTER _
N (%)
STANDING
DEAD
N (%)
MODERATE
0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Figure 63. Chemical composition (%) of STANDING DEAD and
GROUND LITTER in relation to slope position
and grazing pressure, February 1976.
108
-------
summer or fall. From the standpoint of watershed management and water qual-
ity, decreased grazing pressure along streamcourses provides a heavier cover
of standing and ground litter to act as a filter for the overland flow of
suspensed dung and sediment. In this regard we still need to learn how var-
ious amounts and kinds of cover affect runoff quantity and quality. Soil-
plant-grazing animal interrelationships are obviously complex and will con-
tinue to produce more questions than answers. However, since successful
range management depends on the wise application of ecological information,
we believe research in this area and the answers that are forthcoming will
be well worth the effort.
Site Factor Regression Equations (1976-78)
About 88% of the variation in total LIVE plus STANDING DEAD vegetation
biomass could be accounted for using four independent site factors (Table
22). Slope position was the most influential site factor and accounted for
74% (r=+0.86) of the total variation when used alone and 46% of the variation
when used in combination with the other three site factors shown in Table
22. The relationship between total STANDING vegetation and slope position
was curvilinear in that STANDING vegetation was similar on upper and middle
slope positions, but was much greater on lower slope positions. Because A
horizon soil water content was greater on loamy prairie range sites which
occurred downslope, the relationship between standing vegetation and A hori-
zon soil water content was also curvilinear. Although the simple linear cor-
relation coefficient between total soil water and standing vegetation was
+0.64, the regression coefficient for total soil water was -4.71 when used
in combination with the other three site factors in the equation. This may
be a reflection of the high soil water content in soils with a high clay con-
tent in the B horizon.
LIVE vegetation was also strongly influenced by A horizon characteris-
tics, although percent slope accounted for the greatest percentage of varia-
tion in LIVE vegetation. Slopes on the watershed ranged from only 1 to 4%,
but the heaviest grazing pressure occurred on the upper, flatter slopes.
Consequently, LIVE grazing residue was greater where the slopes pitched more
steeply toward the drainageways.
The regression equation for STANDING DEAD was similar to that for LIVE
plus STANDING DEAD. The "best" equation for STANDING DEAD indicated the neg-
ative effect of higher clay content in the B9 horizon with a decrease of about
16 kg/ha STANDING DEAD for each additional 1% clay in the B2 horizon.
Tallgrasses, being deep-rooted, increased with an increase in total soil
water (directly- related to soil depth), but decreased with increasing B2 hor-
izon clay content. All four of the site factors in the equation for tail grass
biomass were related to soil water with the B« horizon clay content probably
also reflecting a negative effect on root penetration.
The percentage LIVE in the total standing vegetation was influenced most
strongly, if the equation does accurately reflect cause-and-effect, by A hor-
izon factors. The percentage LIVE was greatest on shallow prairie and other
upland range sites because heavy winter and late summer grazing on upland
109
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TABLE 22. REGRESSION EQUATIONS^/ FOR PLANT (KG/HA) BIOMASS RESPONSE VARIABLES USING SITE FACTORS ON 25
LOCATIONS ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA,
1976-78
Response
Variable (Y^
LIVE +
STANDING DEAD
R2 = 88.4%
Range (1180-3860)
Mean (2200)
LIVE
R2 = 80.9%
Range (660-1710)
Mean (1090)
STANDING DEAD
R2 = 86.1%
Range (510-2430)
Mean (1110)
bi
1032
19.04
9.59
-4.71
2334
-57.31
Slope
130
33.4
11.1
662
0.54
8.33
-15.9
Site Factor (X^ Unit
bo
(Slope position) (3=1 ow)
2
(A horizon soil water) %
Total soil water mm
A horizon nitrogen %
bo
% 55
A horizon organic matter %
A horizon soil water %
A horizon thickness mm
"o
2
(A horizon soil water) %
(Slope position) - -
B2 horizon clay %
% of
R2
52
29
12
7
,+0.77
19
15
11
38
35
20
r
+0.86
+0.80
+0.64
+0.17
1
+0.54
+0.69
+0.36
+0.77
+0.82
+0.04
Range
Min.
(I)4
(6)2
17
0.001
4
1.8
6
10
(6)3
(I)4
12
(xo
Max.
(3)4
(13)2
282
0.188
3.6
13
26
(13)3
(3)4
58
(Continued)
-------
TABLE 22 (Continued)
Response
Variable (Y^
TALLGRASSES
R2 = 86.7
Range (15-400)
Mean (150)
LIVE/(LIVE +
STANDING DEAD)(%)
R2 = 72.85!
Range (23-64)
Mean (50)
bi
1727
-259
-5.81
1.15
20.70
21.38
1276
-0.098
133
897
-5390
Site Factor (X^ Unit
A horizon nitrogen %
bo
B2 horizon clay %
Total soil water mm
A horizon soil water %
Soil water at 10-cm depth %
"o
(A horizon soil water) %
A horizon clay %
A horizon organic matter %
A horizon nitrogen %
% of
R2
7
39
39
11
11
50
25
17
8
r
+0.12
+0.04
+0.60
+0.77
+0.45
-0.43
+0.31
+0.37
-0.01
Range
Min.
0.001
12
17
6
9
(6)4
13
1.8
0.001
(xi}
Max.
0.188
58
282
13
16
(13)4
30
3.6
0.188
Response variable differences due to location were significant at the 0.05 level. All regression
coefficients are significantly different from zero at the 0.05 level.
-------
sites removed much of the STANDING DEAD on these sites. Therefore, A horizon
soil water content and nitrogen content were directly related to STANDING
DEAD and inversely related to the absence of STANDING DEAD.
The relationships between site factors and certain ground cover factors
are shown in Table 23. As indicated before, heavy winter grazing on flatter,
shallow prairie sites reduced STANDING DEAD and increased the percentage of
bare ground. Grainola soils with a higher A horizon clay content than Lucien
soils (both shallow prairie range sites) received higher grazing pressure
and probably greater soil compaction when soils were wet during the winter.
The A horizon soil water content was the only factor with a significant
(P-=0.05) regression coefficient in the regression equation for surface (3-cm
depth) soil temperature. This relationship is probably a reflection of A hor-
izon soil water effect on ground cover since bare soil is wanner than soil
shaded by vegetation.
LIVESTOCK GRAZING
The watershed was grazed by cow/calf pairs or only beef cows throughout
the year except for a 60-day period in August and September. One bull and
15 to 20 unbred cows and and cows with calves usually grazed the watershed
from May through July. Dry cows most commonly grazed the watershed in early
to mid winter before calving. The watershed was grazed by an unusually
large number of animals, 118 cows, only once, from 15 March to 15 April 1977.
The watershed occupies portions of two pastures. About 80% of the water-
shed is in one pasture and 20% in another pasture. Stocking density, grazing
pressure and herbage utilization were calculated for each portion of the
watershed in separate pastures and then adjusted to show average stocking
density (animal units/hectare), grazing pressure (animal units/ 1000 kg of
standing herbage) and utilization (kg herbage/hectare; %) for the watershed.
The stocking density on the watershed for the study period, as shown in
Figure 64, ranged from a low of 0.14 a.u./ha to a high of 0.38 a.u./ha. when
the watershed was grazed. The yearlong average stocking rate was 0.20 a.u./
ha in 1976, 0.34 a.u./ha in 1977 and 0.28 a.u./ha in 1978. Expressed on a
hectare-per-animal-unit basis, the stocking rate was 5.00, 2.94, and 3.57
ha/a.u. in 1976, 1977 and 1978, respectively.
The significance of stocking pressure in the study is related to the
amount of fresh dung deposited daily during grazing and the total dung dep-
osition for the year. Assuming an animal unit (i.e., a 450 kg. cow or equiv-
alent based on metabolic size) ingests an average of 10.0 kg forage per day
on a dry matter basis and the dry matter digestibility coefficient is 0.50,
about 5.0 kg dung dry matter is deposited daily. A stocking density of 0.21
a.u./ha, as it was on the watershed from 22 January to 15 April 1976, would
result in a dung deposition rate of 1.05 kg dung dry matter/ha/day. A stock-
ing density of 0.38 a.u./ha would produce fresh dung at a rate of 1.9 kg dung
dry matter/ha/day.
112
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TABLE 23. REGRESSION EQUATIONS-/ FOR SELECTED GROUND COVER RESPONSE VARIABLES USING SITE FACTORS ON
25 LOCATIONS ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA,
1976-78
CO
Response
Variable (Y.)
BARE GROUND (%)
R2 = 76.2%
Range (3-28)
Mean (13.3)
SOIL TEMP. (C)
R2 = 77.3
Range (17.4-22.9)
Mean (20.2)
bi
23.9
-0.0070
-2.50
0.17
-31.8
22.4
-0.0022
Site Factor (X^ Unit
"o
3
(A horizon soil water) %
Slope %
A horizon clay %
A horizon nitrogen %
"o
(A horizon soil water) %
% of
R2
53
20
14
13
100
Range (X.»
r Min. Max.
-0.75 (6)3 (13)3
-0.67 1 4
-0.12 13 30
-0.27 0.001 0.188
-0.88 (6)3 (13)3
-'Response variable differences due to location were significant at the 0.05 level. All regression
coefficients are significantly different from zero at the 0.05 level.
-------
0.5
< 0.4
O
\
d
60.3.
>»
8
~(
O
c/5
0.0
r
Annuol Average
WINTER1 SP ' SUM "FALL1 Wl
i IO"7£* '
iyrb
NTER ' SP ' SUM 'FALL' ww
1 IQ-?~7 1
iy ^ (
ITER ' SP ' SUM 'FALL'
1 IQ~7O i
iy rtj
Figure 64.
Stocking density (animal units/ha) during the
study period.
These figures are annual averages, but can be used to approximate seas-
onal averages. Forage ingestion is dependent on digestibility, and digesti-
bility is dependent on many factors. The major factors affecting digesti-
bility include the percentage of green forage in the diet and the phenological
stage of the green forage. In May and June there is adequate green forage
available and it is the major part of the forage material ingested. During
this season the green forage is in a vegetative stage and dry matter digesti-
bility is 60 to 65%. The rate of ingestion at this time is about 14.0 kg
dry matter/a.u./day. Consequently the dung deposition rate at a 0.35 a.u./ha
stocking density is about 1.7 kg dung dry matter/ha/day . During late winter,
the ingested material is all standing dead, the ingestion rate is about 8.0
kg/a.u./ day and the dry matter digestibility is 40 to 45%. With a stocking
density of 0.35 a.u./ha, the dung depositon rate would also be about 1.7 kg
dung dry matter/ha/day.
The major consideration concerning potential pollution is, therefore,
stocking density and dung degradation rate. Because of weather conditions,
biological activity and the dung chemical components, dung deposited in the
spring and early summer disintegrates most rapidly and is most rapidly
114
-------
incorporated into the ground litter and soil. Disintegrated dung is also
subject to movement by overland flow of runoff unless the movement is retarded
by standing vegetation and ground litter. Therefore a more accurate measure
of potential dung movement is grazing pressure or the ratio of stocking den-
sity to standing herbage. The lower the grazing pressure, the greater the
ratio between herbage biomass and the dung to be held on the watershed by
the herbage.
The grazing pressure (a.u./lOOO kg standing herbage) for the watershed
during the study is shown in Figure 65. In general grazing pressure was less
variable than stocking density.' However, the potentially high pollution per-
iod in late winter is shown more clearly. During this period standing herbage
biomass is relatively low because of winter grazing and pressure from snow
and freezing rain. If the stocking density is relatively high during this
period and significant runoff occurs from late winter snow or early spring
rains, there is less standing vegetation to retard dung movement into stream
channels.
Additional research should be conducted to determine the exact relation-
ship between herbage biomass, plant species composition, dung movement and
factors affecting amount and season of runoff. There may be a threshold or
minimum amount of standing vegetation which can be maintained to minimize
dung movement. Similarly, there may be an optimum grazing pressure which
produces high beef production yet maintains range sites in good condition
and retains animal wastes on the watershed. Since comparable adjacent water-
sheds are uncommon, collecting hydrologic water quality, vegetation and graz-
ing data on the same watershed over a long period of time may be the most
practical and most accurate research approach.
UTILIZATION
Yearlong
Utilization by cattle of the live vegetation, by species classes, and
of the standing dead vegetation was used to determine vegetation removed or
trampled and various factors related to forage value, diet composition, selec-
tivity and temporary changes in herbage composition due to grazing (Table
24). Determining utilization by the movable cage method requires an extremely
large number of paired samples because of the inherent high degree of varia-
bility in biomass among the small, 0.5-m2 quadrat samples. Natural variation
in vegetation, site preference, and spot grazing by cattle and possible
effects of cages on vegetation growth and rodent use are some of the major
factors contributing to the difficulty. However, in lieu of esophageal fistu-
lated animals for determining intake and diet composition, the movable cage
method remains the most accurate and practical method of determining utili-
zation by grazing animals on rangeland.
The values for Table 24 were determined by averaging caged and grazing
residue species class biomass separately for the 175 samples (7 sampling dates
X 25 samples/date). All other utilization-related factors were determined
from these averages. Therefore, there is a measure of variability for biomass,
but not for the derived factors.
115
-------
U.U1U
CJ>
0 0.035 -
0
O
\ 0.030 -
3
O
- 0.025 '
0)
3 0.020 -
in
" 0.015
a.
^0.010
M
° O.005
CD
0.000 -
1 1
i
1 '
I . 4
i i
i i
1 i i
WINTER ' SP ' SUM* ' FALL ' WINTER ' ' SP ' SUM' ' FALL ' WINTER ' SP ' SUM ' FALL '
i |Q7£ 11 . IOV7 II IQ7Q 1
Figure 65. Grazing pressure (animal units/1000 kg herbage) during the study period.
-------
TABLE 24. AVERAGE YEARLONG (7 UTILIZATION PERIODS^/; 25 PAIRED SAMPLES/PERIOD) CAGED AND GRAZED
HERBACEOUS SPECIES CLASS BIOMASS AND UTILIZATION FACTORS ON A TALLGRASS PAIRIE WATERSHED
GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Species
Class^/
LIVE +
DEAD
STANDING
DEAD
TOTAL
LIVE
GRASSES
Tall
SCSC
Mid
Short
c.s.
Other
FORBS
Spring
Early
Late
Caged
(kg/ha)
2975
1645
1330
890
195
315
200
65
65
55
440
60
140
245
Grazed
(kg/ha)
2025
1110
915
625
155
195
165
45
35
35
295
35
95
165
Util
(kg/ha)-
950
535
415
270
40
120
35
20
30
. 20
150
25
45
80
ization
3/ (%)1/
31.9
32.5
31.2
30.0
20.0
38.6
18.1
31.3
48.8
37.0
33.8
40.7
33.0
32.6
Forage
Value
Index-^/
18.0
13.9
20.1
2.9
9.1
2.7
1.5
2.4
1.6
11.2
1.8
3.4
6.0
Diet Selec-
Comp. tivity
(%)& Index-/
56.2
43.8
64.3
9.4
29.0
8.6
4.8
7.7
5.0
35.7
5.5
11.0
18.9
1.02
0.98
0.96
0.64
1.23
0.64
1.02
1.57
1.19
1.08
1.28
1.06
1.03
[ Herbage
Composition %
Caged
55.3
44.7
66.9
14.7
23.5
14.9
4.7
4.9
4.2
33.1
4.3
10.4
18.3
Grazed
54.8
45.2
68.0
17.1
21.0
17.8
4.7
3.6
3.8
32.0
3.8
10.1
18.0
Diff.-8^
-0.5
+0.5
+1.1
+2.4
-2.5
+2.9
0.0
-1.3
-0.4
-1.1
-0.5
-0.3
-0.3
-------
TABLE 24 (Continued)
Cage production and grazing residue sampled at end of each utilization period. Utilization periods
include 12 Apr - 22 Jun 76 (71 days), 23 Jun - 17 Aug 76 (56 days), 18 Aug 76 - 29 Apr 77 (255 days),
30 Apr - 8 Jul 77 (70 days), 9 Jul 77 - 28 Mar 78 (263 days), 29 Mar - 12 Jul 78 (106 days), and 13
Jul - 9 Oct 78 (80 days). Refer to Figure 65 for grazing periods and grazing pressure.
21
Shrubs excluded because of low biomass, but very high variability. Herbaceous species classes include
tallgrasses, Schizachyrium scoparium (SCSC), midgrasses, shortgrasses, cool season grasses, other
grasses, spring forbs, early summer forbs and late summer forbs. Refer to Appendix K for listing of
species in species classes.
Caged production - Grazed residue (e.g., Tall: 195 kg/ha - 155 kg/ha = 40 kg/ha).
-Utilization (kg/ha)/Caged production (e.g., Tall: 40 kg/ha/195 kg/ha = 20.0%).
-/(Utilization (%) X Caged composition (%)) X 100 (e.g., Tall: 20.0% X 14.7% X 100 = 2.9).
Utilization (kg/ha) of a species class/Utilization (kg/ha) of all species combined, (e.g., Tall:
40 kg/ha/415 kg/ha = 9.4% tallgrasses in diet).
Composition of a species in diet (%)/Composition (%) of that species in total caged (available)
herbage (e.g., Tall: 9.4%/14.7% = 0.64).
-/Grazed (%) - Caged (%) (e.g., Tall: 17.1% - 14.7% = +2.4%).
-------
When utilization-related factors are determined per period, one or more
species classes was determined to have a negative utilization for one or more
periods. Although significant growth stimulation due to grazing is unlikely,
cages in place for several months can have a negative effect on vegetation
growth or provide for a more favorable habitat for rodents and insects.
These may actually cause "negative utilization" by decreasing caged produc-
tion. Usually, however, the negative utilization, based on only 25 paired
samples, is due to chance where grazed and caged values are very similar.
Since a negative utilization of one species class affects values for other
species classes in succeeding computations, negative utilization creates cap-
ricious values for forage value index, diet composition, and selectivity
index values.
The values presented in Table 24 are useful as long as the reader is
aware of the many factors affecting grazing and utilization. Furthermore,
the values presented in Table 24 for the watershed are similar to those de-
rived using 19 growing-season and 12 dormant-season sampling dates for
paired exclosure and adjacent grazed samples. Therefore, values in Table 24
can be used to describe average species class utilization for the entire 30-
month study period, but not, with as much confidence, for separate periods
within the 30-month study period.
The average, total LIVE and STANDING DEAD herbage utilized between 12
April 76 and 9 October 78 was 950 kg/ha or about 32% of the herbage avail-
able. This value (32%) is lower than the often-quoted maximum desirable
utilization figure of 50%. The exclosure study, using 19 sampling dates dur-
ing the growing season, showed that the average total LIVE vegetation in the
exclosures was about 42% greater than that outside the exclosures. Even with
relatively heavy winter grazing on the upper, slopes, exclosures had only 50%
more STANDING LITTER (31 sampling dates) than adjacent grazed areas.
The proportion of LIVE vegetation utilized (31.2%) was about the same
as the proportion of standing dead utilized (32.5%). STANDING DEAD persists
throughout the year and only a small amount of green vegetation is available
during the dormant season. Consequently, the palatability and forage value
of STANDING DEAD should be of significant concern to the rangeland grazing
manager. The palatability and forage value (chemical composition and diges-
tibility) of STANDING DEAD, as well as that of LIVE vegetation, should also
be of concern to the watershed manager since 1) animal waste chemical compo-
sition is influenced by forage chemical composition (and by supplementation)
and 2) dung deposition location is greatly influenced by site preference of
grazing animals.
Within the LIVE vegetation, about 30% of the grass biomass and 34% of
the forb biomass was utilized. These data indicate forbs, relative to
grasses, are utilized to a much greater extent than commonly thought by
those associated with livestock management, but not experienced in determin-
ing rangeland livestock or wildlife diets.
Several other utilization values are also somewhat contrary to "popular
opinion." Utilization values for tall and midgrasses were lower than those
for any forb species class and lower than those for shortgrasses, cool season
119
-------
grasses (primarily Bromus japonicus) and Schizachyrium scoparium (SCSC, little
bluestem). Although these comparisons contradict the commonly held opinion
that tallgrasses are the most preferred species, these utilization figures
are the result of site selection as well as species selection. In addition,
these values include utilization data from two winter grazing periods. Tall-
grasses were least abundant on the sites most frequently selected for grazing
by cattle. After plant maturity, tallgrasses are relatively rank (fibrous)
and are not as palatable to grazing animals as are the plants of species with
higher leafrstem ratio or with smaller stems. These data indicate the impor-
tance of understanding livestock grazing behavior and site preference on
rangeland watersheds with a wide variety of soils and topographic conditions.
Results from small, uniform watersheds may be misleading if extrapolated to
large, diverse rangeland watersheds.
Based on utilization (%) and available herbage composition (%), grasses
were twice as important for forage as were forbs. Of all species classes,
SCSC had the highest forage value index and was about three times more impor-
tant as forage than were tallgrasses. In fact, SCSC was only slightly less
important than all other grasses combined. SCSC should definitely be consid-
ered a key species on this watershed.
Grasses were estimated to contribute about 64% of the diet; forbs contri-
buted the remaining 36%. These values, as well as all other values pertaining
to species classes, are only for LIVE plants. STANDING DEAD vegetation was
not differentiated as to species. Since grass plants are generally more resis-
tant to weathering than are forbs after plant maturity, grasses no doubt con-
tribute more than 64% of the diet during the winter period.
Forage value index figures for different species are based on availabil-
ity and utilization and are therefore more independent of each other than
are the values for diet composition. Diet composition values are influenced
by availability and selectivity. Any selectivity index value near 1.0 indi-
cates that species class was selected in about the same proportion as its
availability. A selectivity value more than 1.0 indicates that species class
was preferred and a selectivity value of less than 1.0 indicates that species
class was not preferred.
In this study, SCSC, cool season grasses and spring forbs were preferred
species classes, whereas tall and midgrasses were not preferred. During the
fall, winter, and early spring, cool season grasses and spring forbs provide
almost all of the green forage. Consequently, they are highly preferred at
this time. The high selectivity index value for SCSC suggests, on a yearlong
basis, SCSC is much more palatable than commonly thought. One reason SCSC
is assumed to be somewhat unpalatable is its growth habit. SCSC is a bunch-
grass and produces a significant number of ungrazed seed stalks. These are
observed at the end of the growing season and interpreted as a sign of an
unpalatable species. However, SCSC is a relatively late-maturing species,
produces vegetative growth late into the summer and produces a significant
number of leaves on the outer edge of the bunch. All leaf material during
the vegetative phenological stage and the outer leaves after stem elongation
are readily grazed by cattle.
120
-------
The differences in herbage composition for caged and grazed samples were
closely related to the selectivity index values. The preferred species
classes had a lower percent composition in grazed samples and the less palat-
able species classes had a higher percent composition in grazed samples.
Grazing Period
Utilization values and differences for selected site factors within cages
(ungrazed) and outside cages (grazed) for the seven utilization periods during
the 30-month period are shown in Table 25. Utilization was considered the
difference between the 25 caged and grazed, paired samples at the end of each
utilization period including spring, summer and late summer to late winter
or early spring periods. The length of the utilization periods varied from
56 days in the summer of 1976 to 263 days from mid summer, 1977 to late winter,
1978.
As expected, differences in utilization values were primarily due to
differences in stocking density, the length of utilization period and the
season of grazing. Therefore, interpretations concerning differences in util-
ization values should consider the influential conditions. The major value
of the figures shown in Table 25 is in the context of how much biomass was
removed by cattle during each period and the magnitude of influence of graz-
ing on different watershed plant and soil factors during each period.
Because grazing periods varied in length, the amount utilized during a
grazing period was divided by the length of that grazing period to provide a
utilization-per-day figure. The total standing vegetation utilized per day
varied from 0.5 kg/ha/day to 15.7 kg/ha/day. Utilization-per-day (UT/D)
values were generally highest during spring and early summer and lowest dur-
ing winter when forage digestibility is also lowest. The utilization figures
for the 1978 late summer period were consistently low for all vegetation com-
ponents. Grazing pressure was relatively low during this period, but not
low enough to cause the values shown for Sampling Date 8343. Apparently,
there was a difference in plant growth inside and outside the cages or signif-
icant nonlivestock utilization inside the cages. UT/D values for LIVE and
for STANDING DEAD were similar in magnitude only during the first grazing
period during the spring and early summer, 1976. After that period, the pref-
erence for LIVE during the growth season was obvious. Utilization of STAND-
ING DEAD was greater during the winter when there was very little choice.
These utilization figures include trampling loss as well as ingestion.
Trampled STANDING DEAD is converted to herbaceous and woody GROUND LITTER,
whereas about 55 to 65% of the ingested STANDING DEAD is recycled to GROUND
LITTER as dung.
The UT/D values for LIVE and the different species classes of LIVE for
the period ending 7180 (29 April 77) are somewhat misleading. The total LIVE
utilized during this period was 690 kg/ha, but most of this utilization oc-
curred in about 45 days instead of over the 255-day grazing period. Very
little LIVE material is available before 15 March during average growing con-
ditions. When the UT/D values were calculated during 45 days instead of 255
days, the UT/D values were 5.7 times greater. For example, UT/D for LIVE
was 15.3 kg/ha/day assuming all of the difference between caged LIVE and
121
-------
TABLE 25. AVERAGE GRAZING PERIOD (25 PAIRED SAMPLES/GRAZING PERIOD) BIOMASS (KG/HA, OVEN-DRY) AND
SELECTED SITE FACTOR DIFFERENCES BETWEEN CAGED (UNGRAZED) AND GRAZED SAMPLING LOCATIONS
ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-1978
ro
Site
Factor
LIVE + DEAD
STANDING
DEAD
LIVE
GRASSES
Tall
Sampl e-'
C
G
UT
UT/D
C
G
UT
UT/D
C
G
UT
UT/D
C
G
UT
UT/D
C
G
DT
UT/D
6234
3750a^/
2635a
1115b
15. 7a
1845bc
1275a
570b
8.0a
1905ab
1355ab
550a
7.7a
1230a
970a
260ab
3.7abc
270ab
255a
15
0.2ab
Sampling
6290
2960abc
2400a
560bc
lO.Oabc
1420cd
1255a
165bc
2.9abc
1540b
1145b
395ab
7. lab
HOOa
830a
-270ab
4. Sab
I
265ab
165a
"ioo~
1.8a
Date (End
7180
3635ab
1590c
2045a
S.Oabcd
2540a
HOOa
1440a
5. Sab
llOOc
410d
690a
2.7bcd
780b
265c
5T5a~
2.0bcd
115bc
40bc
~75~~
O.Sab
of Grazing Period)-' 0/
7250
2795bc
1845bc
950b
13.6ab
1035d
645b
390bc
5.5ab
1760ab
1195b
565a
8.0a
1230a
770a
460a
6.6a
275a
235a
40
O.Sab
8148
2200c
1015d
Il85b
4.5cd
2165ab
lOOOab
1165a
4.4abc
3.4d
17e
17c
O.ld
15c
lid
~4"b~
O.Od
Ic
Ic
O.Oab
8254
3280ab
2600a
680bc
6.4bcd
1200cd
1075ab
125bc
1.2bc
2080a
1525a
555a
5.2abc
1295a
970a
325a
3.0bcd
335a
250a
-85-
O.Sab
8343
2230c
2190ab
40c
0.5d
1305cd
1420a
-115c
-1.3c
925c
770c
155bc
l.Scd
595b
555b
40b
0.5cd
llObc
145ab
-35
-0.4b
p±/
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
0.40
0.35
(Continued)
-------
TABLE 25 (Continued)
ro
CO
Site
Factor
SCSC
Mid
Short
Cool
Other
FORBS
Sampl e-'
C
G
UT
UT/D
C
G
UT
UT/D
C
G
UT
UT/D
C
G
UT
UT/D
C
G
UT
UT/D
C
G
UT
UT/D
6234
500a
370a
130abc
l.Sabc
250ab
200a
50
0.7
70a
40bc
30~~
0.4
lOOb
90a
lOb
0.2
40bc
15bc
TiB
0.40
670a
390bc
280a
4.0a
Sampling
6290
415ab
265b
150abc
2. Gab
240ab
245a
-5
-0.1
90a
lOOa
-10
-0.3
20d
20d
~0b
0.0
70ab
30b
475
0.7
440bc
315cd
125ab
2.3ab
Date (End
7180
295b
85de
210liF
O.Sbc
125c
55b
~70~
0.3
40ab
15bc
25
0.1
150a
50b
lOOa
0.4
60b
20bc
"413
0.1
315c
145e
170ab
0.7b
of Grazing Period)- , ,
7250
450a
200be
250a
3.6a
295a
215a
~8TT
1.2
95a
70ab
25
0.4
55cd
15c
"4T5b~
0.6
60b
35b
7B~
0.3
530b
425b
105ab
1.5b
8148
Od
Oe
07
0.0
Id
3b
_2
0.0
Ib
Ic
0
0.0
15d
7c
8b
0.0
Id
Oc
1
0.00
19d
6f
13b
O.lb
8254
390ab
295ab
95bc
0.9bc
305a
240a
65
0.6
85a
SOabc
35
0.3
70bc
50b
20b
0.2
105a
85a
"20"
0.2
790a
535a
235a
2.2ab
8343
150c
130cd
20c
0.2c
175bc
185a
-10
-0.1
60ab
25bc
35
0.4
45cd
lOc
35b
0.4
60b
65a
_5
-0.1
330c
210de
120ab
1.3b
p±/
*
*
*
*
*
*
0.41
0.64
*
*
0.54
0.58
*
*
*
0.16
*
*
0.32
0.30
*
*
*
*
(Continued)
-------
TABLE 25 (Continued)
ro
4*
Site
Factor
Spring
Early
Summer
Late
GROUND
LITTER
GROUND +
STANDING
LITTER
LIVE + DEAD
+ GROUND
LITTER
2f
Sampl eP
C
G
UT
UT/D
C
G
UT
UT/D
C
G
UT
UT/D
C
G
Diff.
C
G
Diff.
C
G
DTff.
6234
155a
95a
~60a
0.8a
235ab
150b
~8T~
1.2
285b
145c
140ab
1.9a
2270ab
2980a
-710b
4120ab
4260a
-140bc
6020a
5620a
"?00bc
Sampling
6290
20d
lOd
TOc
O.lb
130bcd
65c
65
1.2
295b
235ab
60bc
l.Oab
1820abc
2860ab
-1040b
3240bc
4120a
-880bc
4780abc
5260ab
-480bc
Date (End
7180
HOb
55b
55ab
0.2b
120cd
55cd
~55~
0.3
85c
35d
50bc
0.2b
1740abc
1760bcd
-20ab
4280ab
2500b
1780a
5380ab
3050cd
2330a
of Grazing PeriodP/ ,,
7250
40cd
25cd
0.2b
ISOabc
HOb
40
0.6
310b
260ab
50bc
0.7ab
1050c
1040d
~~10ab
2080c
1680b
400b
3840c
2880cd
960ab
8148
5d
3d
O.Ob
7e
2d
5
0.0
6c
. 2d
O.Ob
2355a
1540cd
81 5a
4520a
2540b
1980a
4550bc
2560d
1990a
8254
60c
45bc
isr
O.lb
275a
220a
-55-
0.5
455a
290a
T65a
1.6e
1700abc
1480cd
220ab
2900c
2550b
340b
5000abc
4080bc
920ab
8343
25cd
5d
20bc
0.2b
25de
20cd
5
0.1
280b
190bc
90abc
l.Oab
1475bc
2460abc
-985b
2780c
3880a
-llOOc
3710c
4650ab
-940c
P^
*
*
*
*
*
0.68
0.49
*
*
*
*
*
*
*
*
*
*
(Continued)
-------
TABLE 25 (Continued)
ro
en
Site
Factor
LIVE %
SOIL WATER (%)
(A horizon)
SOIL TEMP. (C)
Sample-'
C
G
Diff.
C
G
"DTff.
C
G
Diff.
Sampling Date (End of Grazing Period)
6234
56. 2b
55.8bc
0.4
5.9b
5.2a
0.7
24. 6b
25. 2c
-0.6
6290
56. 6b
50. Oc
6.6
2.6c
3.5d
-0.9
26.9a
27. 4b
-0.5
7180
36. 7c
27.9e
8.8
M
7.3c
«.
19. 2e
7250
65. 3a
64. 5a
0.8
4.8bc
5. led
-0.3
25. Ob
25.5bc
-0.5
8148
2.4d
2.7f
-0.3
15.0
17. 6a
-2.4
10. 4c
11. 4f
-1.0
8254
65. 3a
60.2ab
5.1
4.9bc
6.3cd
-1.4
28. 5a
29. 4a
-0.9
8343
42. 3c
37. 2d
5.1
12. 6b
22. Id
p3/
*
*
0.13
*
*
0.42
*
*
0.76
-Sampling date (Plant year = 1 Nov. - 31 Oct.) :6 = 1976; 6234 = 234 days after 1 Nov. 1975.
Grazing periods: 6234 (120476 - 220676 = 71 days), 6290 (230676 - 170876 = 56 days), 7180 (180876
290477 = 255 days), 7250 (330477 - 080777 = 70 days), 8148 (090777 - 280378 = 263 days),
8254 (290378 - 120778 = 106 days), 8343 (130778 - 091078 = 89 days).
-f C = Caged, G = Grazed, UT = Utilization, Diff = G - C, UT/D = Utilization/day.
I/
Probability level (* = P 0.05).
Those values in the same row followed by the same letter are not significantly different at the
0.05 level.
-------
grazed LIVE was caused by grazing in the last 45 days of the grazing period.
UT/D values for the different species classes of LIVE can be adjusted accord-
ingly.
GRASS UT/D values were generally highest during summer grazing periods
whereas FORBS UT/D values were highest during spring grazing periods. Tall-
grasses, SCSC, spring forbs and late summer forbs were the only species
classes whose UT/D values were significantly (P-^.05) different due to graz-
ing periods. As reflected by UT/D values for GRASSES and FORBS, tallgrasses
and SCSC were utilized to a greater extent during summer grazing periods and
spring forbs were utilized more during the spring and early summer grazing
periods. The late summer forbs UT/D value for the late summer period in 1978
was relatively higher than those of other species classes during this period.
The late summer forbs UT/D value for the 1977 summer period (7250) was rela-
tively lower than those for comparable grazing periods in 1976 (6290) and
1978 (8254). Late summer forbs production peaked earlier in 1977 than in
1976 or 1978 (Figures 53, 54 and 55, pp. 84-86). Earlier maturity in 1976
may have hastened the production of anti-quality components normally assoc-
iated with late maturing, perennial forbs.
The conversion of LIVE and STANDING DEAD to GROUND LITTER is partly re-
flected in the low differences between caged and grazed GROUND LITTER values.
The accumulation of dung and fresh GROUND LITTER on grazed areas produced
GROUND LITTER values as high or higher on grazed areas as for caged samples.
Differences in GROUND LITTER values for caged samples and for grazed samples
due to grazing period are also influenced by the removal of all dung within
all sampling areas in the spring of 1977. This is why GROUND LITTER values
were lowest on the 8 July 77 sampling date.
Grazing decreased LIVE (%) during most grazing periods, but differences
due to grazing period were significant at only the 0.13 level. The largest
difference in LIVE (%) was in late April 77 (7180) when cattle was concentrat-
ing grazing on succulent spring forage. Soil water content (%) in the A hor-
izon and soil temperatures were generally higher on grazed areas, but differ-
ences due to grazing periods were not significant at the 0.05 level nor were
trends evident.
Effect of Site Factors
Several regression equations were developed to determine which site fac-
tors accounted for the greatest amount of variation in utilization (%) of
LIVE and LIVE + DEAD (STDV) vegetation for the seven grazing periods. Regres-
sion equations shown in Table 26 may include either LIVE grazing residue or
LIVE caged production, but not both in the same equation. If values were
available for both grazing residue and caged production, utilization could
be calculated directly without using a prediction equation.
The 25 locations were used to provide site factor values. Utilization
values per location were the average utilization values for the seven sampling
dates.
126
-------
TABLE 26. REGRESSION EQUATIONS^/ FOR VEGETATION UTILIZATION (%) USING SITE FACTORS ON 25 LOCATIONS ON
A TALLGRASS PRAIRIE GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
ro
Yi
LIVE
7 = 30.5%
Range (1.7-59.4%)
R2 = 73.3%
SE = 1.6%
LIVE
R2 = 64.9%
SE = 1.9%
LIVE
R2 = 51.1%
SE = 2.2%
DEAD
Y = 31.5%
Range (2.9-57.0%)
R2 = 71.3%
SE = 2.2%
bi
25.2
-0.043
-1.081
+1.00
+4.57
23.6
-1.27
+0.027
-12.1
+0.0076
-7.102
-1.374
0.012
0.256
0.142
-104.0
0.210
0.383
1.56
0.386
Site Factor (X..)
b
LIVE graSing residue «/
(Moisture economy index)
Percent tall grasses
Soil water at 10-cm depth
b
(Moisture economy index)2
LIVE caged production
A horizon organic matter
A horizon calcium
b
(Moisture economy index)2
A horizon calcium
A horizon sodium
A horizon soil water
b
A horizon potassium
A horizon sodium
A horizon thickness
B2 horizon sand
Unit
kg/ha
- -
%
%
- _
kg/ha
%
ppm
- -
ppm
ppm
%
PPm
ppm
cm
%
% of
R2
26
16
16
15
28
21
10
6
20
15
10
6
36
17
11
7
r
-0.54
-0.51
-0.06
-0.04
-0.51
+0.17
-0.32
+0.06
-0.51
+0.06
+0.44
-0.25
+0.52
+0.48
+0.19
+0.24
Range
Min.
660,,
(0.33T
2.0
9.2
(0.33)2
810
1.8
1560
(0.33)2
1560
35
6
230
35
10
11
(X^
Max.
1710
(5.04)2
30.9
15.9
(5.04)2
2200
3.6
3950
(5.04)2
3950
123
13
475
123
26
82
(Continued)
-------
TABLE 26 (Continued)
ro
oo
LIVE +
7 =
Range
R2 =
SE =
LIVE +
R2 =
SE =
Yi .
DEAD
30. 3%
(11.1-50.4%)
70.9%
1.5%
DEAD
63.0%
1.7%
bi
-36.8
0.
0.
0.
-4.
344
019
088
388
-55.3
0.
0.
1.
0.
115
306
110
242
Site Factor (X..)
b
A horizon
LIVE caged
A horizon
Slope
b
A horizon
A horizon
A horizon
B2 horizon
sodium
production
potassium
potassium
sodium
thickness
sand
Unit
ppm
kg/ha
ppm
%
ppm
ppm
cm
%
% of
R2
29
18
14
9
23
22
12
6
r
+0.
+0.
+0.
-0.
+0.
+0.
+0.
+0.
55
37
36
20
36
55
25
22
Range
Min.
35
810
230
1
230
35
10
11
(X.)
Max.
123
2200
475
4
475
123
26
82
-J. All equations and regression coefficients (b.) are significant at the 0.05 level
-' MEI = Aspect x Slope (%). 1
-------
LIVE utilization averaged 30.5% and ranged from 1.7 to 59.4% for the 25
locations sampled. About 73% of the variation in LIVE utilization could be
accounted for using LIVE grazing residue, moisture economy index (MEI), per-
cent tallgrasses in LIVE and soil water content at the 10-cm depth. LIVE
grazing residue accounted for 26% of the LIVE utilization variation and the
other variables collectively accounted for the other 47%. LIVE utilization
was lower in areas with greater grazing residue and higher MEI values. Gen-
erally, these areas were on deeper soils on lower slope positions. The posi-
tive sign for percent tallgrasses and 10-cm depth soil water content regres-
sion coefficients is somewhat contradictory with the influence of MEI and
grazing residue. Although percent tallgrasses are generally closely associ-
ated with LIVE grazing residue and MEI, cattle apparently preferred certain
soils within the range of MEI and grazing residue. For example, Grainola
soils have a higher A horizon soil water-holding capacity and fertility than
Lucien soils and cattle were observed to graze on Grainola soils to a greater
degree than on Lucien soils.
When caged LIVE production was used in a regression equation in place
of LIVE grazing residue, only 65% of the variation in LIVE utilization was
accounted for. LIVE utilization increased as LIVE caged production increas-
ed when the concurrent effects of MEI, A horizon organic matter content and
A horizon calcium were taken into account. The positive sign for A horizon
calcium content also indicates A horizon soil fertility may be a compensating
factor on more xeric (lower MEI) sites.
When no plant factors were used as independent variables to predict util-
ization, only 51% of the variation in LIVE utilization could be accounted
for. MEI accounted for 20% of the variation and A horizon factors accounted
for the other 31%. A horizon calcium, sodium, and soil water contents were
directly related to LIVE utilization.
Percent utilization of standing dead vegetation (DEAD) averaged 31.5%
and ranged from 2.9% to 57.0%. About 71% of the variation in DEAD utilization
was accounted for using A horizon potassium and sodium contents, A horizon
thickness and B2 horizon sand content. All of these independent, abiotic
site factors were directly related to DEAD utilization. No regression equa-
tion using plant production or species composition values accounted for more
of the variation than that accounted for using only abiotic factors. This
may reflect the preference for certain sites during the winter more than a
preference for production or species. DEAD utilization was not highly corre-
lated with LIVE utilization (r=+0.33). Therefore, locations preferred for
utilization of LIVE vegetation were not consistently preferred for utiliza-
tion of DEAD vegetation.
The correlation coefficients between LIVE and STDV utilization and be-
tween STANDING LITTER (STDL) and STDV utilization were +0.66 and +0.88,
respectively. This was as expected since STDL utilization occurred yearlong,
but LIVE utilization was significant only during the growing season.
The average utilization for total standing vegetation (STDV) was 30% or
about the same as for utilization of LIVE or DEAD. However, the range in
STDV utilization (11-50%) over the 25 locations was much less than that
129
-------
(2-5955)-for LIVE utilization or that (3-57%) for DEAD utilization. About
71% of the variation in STDV utilization could also be accounted for with
independent site factors. LIVE caged production was more influential than
either LIVE grazing residue or total standing vegetation. The "best" four-
factor regression included A horizon sodium content (29% of variation), LIVE
caged production (18%), A horizon potassium content (14%) and percent slope
(9%). STDV utilization decreased with increasing steepness of slope (1 to
4% slopes) and increased with increases in the other equation factors.
When only abiotic site factors were used in the regression equation,
A horizon potassium and sodium contents, A horizon thickness and B^ horizon
sand content accounted for 63% of the variation in STDV utilization. This
equation was very similar to the one which accounted for the greatest amount
of variation in DEAD utilization.
The strong effect of minor differences in soil fertility and A horizon
characteristics was also indicated by the fact that differences in LIVE, DEAD
and STDV utilization between loamy prairie and shallow prairie range sites
were small and not significantly different at less than the 0.60 level.
Therefore, differences in utilization appear to be related to soil and topo-
graphic differences within range sites and to management factors, such as
location of water, salt grounds, and feeding areas.
PLANT CHEMICAL COMPOSITION AND DIGESTIBILITY
Seasonal Variation
Seasonal variations in nitrogen, phosphorus, potassium, and calcium con-
tents (%) for the April 76 to April 77 period are shown in Figures 66, 67,
68, and 69, respectively. Chemical components in LIVE, STANDING DEAD, GROUND
LITTER, and DUNG are shown in each figure.
Nitrogen
The Kjeldahl nitrogen content in LIVE plant material declined from 2.4%
in April to 1.3% in August 1976 (Figure 66). The decrease in nitrogen con-
tent with increased maturity is consistent with the findings of other
researchers; however, the rapid rate of decrease was also indicative of
drought and the relatively early maturity of certain species. By August,
production had peaked and began to decline for all species classes except
shortgrasses and late summer forbs. The increase in nitrogen content between
August and September appeared to be in response to regrowth and an increased
percentage of late summer forbs. Differences in dung nitrogen content in
June, July, August and September were relatively large and significant, but
the explanation for these differences was not apparent. Kautzsch et al.
(1977) found the nitrogen content in fresh dung deposited on this watershed
in July 1976 decreased only slightly from 1.9% to 1.7% in 140 days. The rel-
atively consistent dung nitrogen content between October and March was the
result of the protein and hay feeding.
GROUND LITTER was the most consistent of the materials analyzed in regard
to nitrogen content. Average nitrogen content varied only 0.2%, but was
130
-------
* Live
Dung
o Ground Litter
Standing Dead
DL Standing Dead + Live
Figure 66. Average monthly Kjeldahl nitrogen
content (%) of plant materials
and dung during the April 1976
- March 1977 period. (Between-
months probability levels or
LSD OR were LSD n(- = 0.015%,
P<0:T9%, LSD n(- - 0.29%,
P<0.17 and P^OTIO for LIVE,
Dung, GROUND LITTER and STAND-
ING DEAD, respectively.)
slightly lower during winter than during summer. STANDING DEAD material was
consistently lower in nitrogen content, but did indicate seasonal trends. The
increase between April and late May would reflect the death of cool-season and
early spring grasses and forbs. Leaching reduced the nitrogen content between
May and July. With increased drought stress, leaves or entire plants of
later-maturing species died and were classified as standing dead.
Phosphorus
Changes in phosphorus content in different plant materials between
monthly samples were similar to change in nitrogen content in comparable
plant materials (Figure 67). The lowest phosphorus levels in LIVE material
and dung occurred earlier than did the lowest nitrogen levels, but the pat-
terns were similar. Seasonal changes in dung phosphorus content were less
erratic than those for dung nitrogen content. Increased concentration during
digestion (Bromfield and Jones, 1970), relatively low mobility and free-
choice intake of the phosphorus mineral may have caused the more consistent
change in dung phosphorus content between July and late January.
131
-------
o
c.
a.
0.27
0.25
0.23
0.21
0.19
°-17
0.15
0.13
O.I I
0.09
0.07
0.05
0.03
0
* Live
Dung
o Ground Litter
A Standing Dead
DL Standing Dead + Live
AMJJASONOJFM
Figure 67. Average monthly phosphorus content
(%) of plant materials and dung
during the April 1976 - March 1977
period. (Between-months probability
levels or LSD ni- were LSD nc; =
0.015%, puo
LITTER and STANDING DEAD, respec-
tively.)
The phosphorus content in GROUND LITTER was relatively high in spring,
early summer, and January and very uniform between July and December. The
seasonal pattern for phosphorus content in STANDING DEAD material was similar
to that of nitrogen content in STANDING DEAD. The phosphorus content values
were lower in STANDING DEAD than in other materials, had the lowest range
from high to low of all materials and were the most uniform in seasonal
changes.
Potassium
Although the changes in potassium content in LIVE vegetation were similar
to those of nitrogen and phosphorus, the average potassium content in LIVE
vegetation was much greater than that in other materials during comparable
periods (Figure 68). This indicates the high degree of potassium mobility.
When not active in LIVE plant material, it is easily leached from dead mater-
ial (White 1973). Unlike nitrogen and phosphorus, the potassium content was
132
-------
generally lower In dung than in other materials except during late winter
when supplements and hay were fed. The higher potassium content from June
to September than in April and May indicates less leaching during the rela-
tively dry summer months. The high values for potassium in October and Novem-
ber standing dead were due to the LIVE material in these samples.
1.8
1.6
1.4
0.5
0.4
0.3
0.2
O.I
0
A Live
Dung
o Ground Litter
* Stonding Dead
DL Standing Dead < Live
AMJ JASONOJFM
Figure 68. Average monthly potassium content
(%) of plant materials and dung
during the April 1976 - March
1977 period. (Between-months
probability levels or LSD 0
were LSD n, = 0.17%, P<0:27,
LSD n(. ='0:25% and LSD n(. =
0.06*% for LIVE, Dung,'GROUND
LITTER and STANDING DEAD,
respectively.)
Calcium
The values for calcium content in LIVE vegetation were more variable
(P<.12) than those for other nutrients in LIVE vegetation. The pattern of
seasonal change in calcium content did not coincide with the patterns for
nitrogen, phosphorus, or potassium contents (Figure 69). The increase in
calcium content between mid-April and early May appeared to be related to
increased maturity of cool-season grasses and the increase in spring forbs,
many of which were legumes. The calcium content in August coincided with
peak production and a higher percentage of mid-grasses, shortgrasses, and
late summer forbs. The decrease in calcium content between spring and July
with a subsequent increase in August was consistent in LIVE material, GROUND
LITTER and dung. As is generally conceded by many range scientists (Laycock
133
-------
and Price 1970) we found changes in the calcium content over time in different
plant materials to be much more apparent than the explanation for these
changes.
1.0
0.9
0.8
58 0.7
e
I 0.6
o
0.5
0.4
0.3
* Live
Dung
o Ground Litter
a Standing Dead
DL Standing Dead + Live
DL
r i i I i i I i i I I I I
AMJJASONDJFV
Figure 69. Average monthly calcium content
(%) of plant materials and dung
during the April 1976 - March
1977 period. (Between-months
probability levels or LSD nr
were P<12, LSD n_ = 0.17%;
P<0.14 and LSD*"? = 0.08% for
LIVE, Dung, GROUND LITTER and
STANDING DEAD, respectively.)
Compared with chemical analyses of tallgrass prairie vegetation in this
area by other scientists (Briggs et al. 1948, Daniel 1935, Daniel and Harper
1935, Harper 1957, Waller et al. 1972), the average nitrogen and calcium con-
tents in LIVE vegetation was much higher than usual, especially in summer
and fall. Potassium content was about average. Phosphorus content was about
average in the spring, lower during June and July and average or above average
in August and September. The generally higher than reported nutrient content
in our samples was because of a lower percentage of tallgrasses with corres-
ponding higher percentage of mid and shortgrasses and forbs (Savage and Heller
1947), lower rainfall and reduced production (Daniel and Harper 1935, Harper
134
-------
1957) and recycling of nutrients through grazing animals (Rouquette et al.
1973, Watkin 1957) fed supplemental feed (Benacchio et al. 1970).
Nitrogen, phosphorus, and potassium contents in LIVE vegetation decreased
from a high in early spring to a low in summer at a rate that closely resembled
the decrease in soil water content. Changes in STANDING DEAD composition
were uniformly cyclic with seasons and generally reflected the effects of
drought and plant maturity on different species classes. Changes in chemical
composition of dung reflected the effects of nutrient availability in forage
and supplemental feed.
Annual Variation
Vegetation for chemical analyses was not collected on the same calendar
date nor at the same phenological stage during each of the three years of
the study period. Therefore, trends within years are more signficant than
are annual averages. Furthermore, chemical composition can be expected to
vary with differences in annual growing conditions, species composition, and
species utilization by grazing cattle.
Live Vegetation
As expected, nitrogen phosphorus, and potassium contents declined each
year with increasing plant maturity (Table 27). For certain components,
there was a slight increase in late summer as late summer forbs became more
abundant or late summer rains promoted new growth. Calcium values were rela-
tively consistent throughout the growing seasons except in 1977. The highest
calcium content of that year and all three years was in Vegetation collected
in early September.
In 1978, nitrogen contents were generally lower throughout the growing
season than in other years. Vegetation production of most species classes
was highest in 1978. Much of the increased production during years of favor-
able growing conditions is stem material, especially in tallgrasses, and a
higher stem:leaf ratio generally causes a decrease in nitrogen content of
the total plant. During years of drought, forage quantity but not forage
quality, is usually the factor limiting livestock production.
Ash contents were determined only in 1977 and 1978. Differences due to
sampling date were highly significant in 1977, but not in 1978. However,
even in 1977, ash contents varied little ranging from a low of 6.6% in early
August to a high of 7.8% in early June. The relatively low ash contents re-
sulted in the small differences between dry matter digestibility (DMD) and
organic matter digestibility (OMD).
The structural carbohydrate components, acid-detergent fiber (ADF), acid-
detergent lignin (ADL) and cellulose (CEL), varied greatly within years and
between years. Most of this variation was attributed to changes in species
composition and changes in plant maturity for different species classes.
Early species, such as cool season annual grasses and forbs, matured earlier
in the growing season than other species classes, but the time and rate of
maturation depended greatly on temperature and soil water content each year.
135
-------
TABLE 27. AVERAGE (25 SAMPLES/DAY) CHEMICAL COMPOSITION (%) OF LIVE VEGETATION ON A TALLGRASS PRAIRIE
GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
DAY
6163
6183
6206
6234
6262
co
<* 6290
6320
7192
7220
725Q
7275
7312
X
P
I/
CHEMICAL COMPOSITION (%)
N
2.34a^/
1.91b
l.Slb
1.49c
1.37c
1.30c
1.42c
1.66
*
2.27a
1.24b
1.13b
1.23b
1.46
*
P
0.18a
0.16b
O.llc
0.07d
O.OSd
0.09c
0.09c
0.11
*
O.lla
O.lOa
0.07b
0.09ab
0.09
*
K
1.90a
1.59b
1.37c
1.28c
1.17c
1.22c
1.17c
1.38
*
1.68a
1.37b
1.13b
1.35b
1.38
*
CA ASH
0.50 -- -1
0.58
0.56
0.54
0.48
0.62
0.58
0.55
0.28
0.59ab 7.5ab
0.55b 7.8a
0.55b 6.9cd
6.6d
0.66a 7.2bc
0.59 7.2
* *
ADF
45.9a
46. 6a
36. 7c
37.8bc
40. 5b
39.3bc
36. Ic
40.5
37. 6b
43. la
43. 7a
42. 2a
42. 2a
41.5
ADL
11. 4b
14. 9a
14. 9a
11. 8b
10. Ib
10. 2b
10. Ib
12.0
*
6.9d
9.2c
11. 3a
10. Ib
9.3c
9.1
*
CEL
32. 3a
22. 8d
29.7bc
31.4ab
31.5ab
30. lab
27. 8c
29.3
*
29.8
31.4
31.6
30.6
31.6
30.9
0.14
DMD
__
35. 4c
43. 9b
50. 5a
45. Ob
42.9
*
48. 2a
46. 8a
49. la
47. 2a
38. 8b
46.1
*
OMD
__
49. 3a
49. 3a
50. la
49. 4a
41. 3b
48.1
*
(Continued)
-------
TABLE 27 (Continued)
DAY
8176
8205
8233
8254
8290
^ 8317
GO
8343
X
P
I/
CHEMICAL COMPOSITION (%)
N
2.16a
1.46b
1.19c
1.04de
l.lOcd
0.93e
0.92e
1.26
*
P
0.20a
O.llc
0.09c
O.OSc
0.09c
O.OSc
0.15b
0.11
*
K
2.41a
1.74b
1.63b
1.55bc
1.42c
1.14d
0.99d
1.55
*
CA
0.62
0.57
0.64
0.64
0.61
0.59
0.54
0.60
0.76
ASH
8.5
7.8
8.0
7.9
7.9
7.7
--
7.9
0.64
ADF
30. 7c
37. 6b
40. 6a
39.0ab
39.0ab
36.9b
__
37.7
ADL
8.0c
9.2abc
10. 4a
lO.Oab
8.5bc
9.0abc
9.3
*
CEL
23. 9c
31. 2a
32. 4a
31. 7a
30. 7a
28. Ob
--
30.0
*
DMD
58. 8a
49. 4b
43. 6c
45.7bc
49. 7b
48. Ob
21. 7d
47.0
*
OMD
58. 9a
50. Ib
45. 2c
47.4bc
51. 3b
48.7bc
--
48.7
*
-/N-Nitrogen, P-Phosphorus, K-Potassium, CA-Calcium, ASH-Ash, ADF-Acid-Detergent Fiber, ADL-Acid-
Detergent Lignin, CEL-Cellulose, DMD-Nylon Bag Dry Matter Digestibility, OMD-Nylon Bag Organic Matter
-.Digestibility.
|^Plant year day: 6 = 1976; 6163 = 163 days after 1 November 1975.
Those values for the same chemical component in the same year followed by the same letter are not
..significantly different at the 0.05 level.
cyChemical analysis not conducted.
^.Average per component per year.
-Probability level (* = P 0.05).
-------
Tall grasses, little bluestem, and late summer forbs were species classes whose
plants matured latest in the growing season.
ADF, ADL, and CEL contents generally increased to a peak in mid summer,
then decreased. This trend was more consistent in 1977 and 1978 than in 1976.
In 1976, the usual summer onset of plant water stress occurred earlier than
in 1977 and 1978. The greatest change in ADL and CEL occurred between mid
April and early May, 1976 with early maturity of plants that usually mature
in mid or late May. Kautzsch (1978) determined significant relationships
between species composition and structural carbohydrate composition during
most of the sampling periods in 1976. Ball (1980) also noted seasonal
changes in structural carbohydrate composition of herbage samples from the
experimental watershed in 1977 and 1978.
Dry matter digestibility (DMD) and organic matter digestibility (OMD)
also varied with year and season. Changes were related to differences in
plant maturity and species composition and the related differences in plant
chemical composition. DMD and OMD were very closely related (r=0.98, all
seasons, all years). Since ASH content was consistently and relatively low
for forage, OMD was consistently, but only 1 to 2% greater, than DMD. There-
fore, further discussion concerning digestibility is restricted to DMD.
Changes in DMD during the growing season each year were not as consistent
as for plant chemical components. DMD was relatively low in the early summer
of 1976 and 1978, increased to a peak in late summer and decreased in early
fall. DMD was not determined in the early spring of 1976 or 1977, but, based
on the literature and the results from 1978, DMD was no doubt highest in early
spring in 1976 and 1977 also. DMD was relatively consistent for most of the
growing season in 1977. A review of the species classes growth curves in
Figures 53, 54, and 55 (pp. 84-86) shows a more uniform period of peak produc-
tion for dominant species in 1977 than for 1976 or 1978. Apparently, those
species classes whose plants undergo a rapid increase in plant water stress
have a significant effect on DMD of the total herbage sample. The recent
review by Hanley (1982) and the work by Hake et al. (1982), Powell (1970),
Nagy and Tengerdy (1968), Nagy et al. (1969) and others indicate significant
relationships between rapid decreases in soil water content, increased plant
water stress, increased volative oils and other anti-quality products and
DMD. However, the DMD of the herbage collected may not be representative of
the DMD of the diet selected by grazing animals if there is adequate plant
species diversity and grazing selection.
Standing Dead
The N, P,, K, and Ca contents of STANDING DEAD vegetation (DEAD) was, as
expected, less variable than that of LIVE (Table 28). The rank order of con-
tents (%) of chemical components is presented to show the apparent effects
of leaching and percent recent dead. In general, the highest values for N,
P, and K were for those samples collected in early fall and very early spring.
These samples included a high percentage of recent DEAD (fall) or a small
percentage of green plants with high N, P, and K contents (spring). Hand
separation of herbage samples is an extremely time-consuming process (i.e.,
about one hour per sample). In fall samples, recent (current year) DEAD is
138
-------
co
TABLE 28. RANK ORDER BY SAMPLING DATE AND NITROGEN (N), PHOSPHORUS (P), POTASSIUM .(K) AND CALCIUM
(CA) CONTENTS (%) IN STANDING DEAD VEGETATION ON A TALLGRASS PRAIRIE WATERSHED GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
RANK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
DAY
7160^
6346
7192
6206
7250
7347
7090
6183
6234
6320
7010
7040
7312
6290
6163
8205
6262
8176
7220
8148
8233
8343
7130
8017
N
1.17.2/
l.lOab
l.OGabc
1.02abcd
0.98bcde
0.96bcdef
0.94bcdefg
0.94bcdefg
0.93bcdefg
0.93bcdefg
0.93bcdefg
0.90bcdefgh
0.87cdefgh1
0.85cdefghij
0.84cdefghijk
0.83defghijk
O.Slefghljk
0.78efghijk
0.77efgh1jk
0.77fghijk
0.75ghijk
0.72hijk
0.71hijk
0.71hijk
DAY
7160
8017
7347
8205
6346
6183
8343
6206
8176
7250
8233
6320
8148
7192
6163
7130
6290
7010
8254
7040
7220
6234
7312
8290
P
0.097a
0.077b
0.072bc
0.060bcd
O.OGObcde
0.057bcdef
0.054cdef
0.051def
0.051def
0.050def
0.050def
0.048defg
0.047defg
0.046defg
0.045defg
0.044defg
0.043defg
0.042defg
0.041defg
0.040defg
0.040defg
0.039defg
0.039defg
0.038efg
DAY
8176
7347
7160
7250
7312
8254
6346
8205
7192
7220
6320
7010
8017
6234
8233
6262
8290
6290
7040
8148
8343
8050
6206
6183
K
1.03a
0.72b
0.61bc
0.54cd
0.53cd
0.51cd
0.51cd
0.38de
0.38def
0.38def
0.37def
0.37def
0.37def
0.32efg
0.30efgh
0.27efgh
0.25efgh
0.25efgh
0.24efgh
0.23efgh
0.22efgh
0.21efgh
0.21efgh
O.lSfgh
DAY
7250
6183
6320
6262
6206
7040
7192
6290
8050
7160
7347
6234
8343
8254
8290
7010
7090
7220
6163
8148
8017
8205
8176
8233
CA
0.57a
0.56ab
0.52abc
0.51abcd
O.Slabcd
0.50abcd
O.SOabcde
0.49abcde
0.49abcde
0.49abcde
0.48abcde
0.48abcdef
0.47bcdef
0.46cdef
0.45cdef
0.45cdef
0.45cdef
0.44cdef
0.44cdef
0.43cdefg
0.42cdefg
0.42defg
0.42defg
0.41defg
(Continued)
-------
TABLE 28 (Continued)
RANK
25
26
27
28
X±SE
DAY
8050
8290
8254
8120
N
0.671jk
0.66jk
0.66jk
0.65k
0.85+0.05
DAY
8050
7090
6262
8120
P
0.038efg
0.036fg
0.035fg
0.027g
0.049±0.006
DAY
7130
7090
6163
8120
K
0.17gh
0.16gh
0.12h
O.lOh
0.36±0.05
DAY
7130
6346
8120
7312
CA
0.39efg
0.38fg
0.34g
0.25h
0.45±0.03
-/Plant year date. 6 = 1976; 7160 = 160 days after 1 Nov 76. Winter = 001 - 135;
Spring = 136 - 211; Early Summer = 212 - 242; Summer = 243 - 304; Fall = 305 - 365.
2/
'Those values In the same column followed by the same letter are not significantly different
at the 0.05 level.
-------
difficult to distinguish from the DEAD of the previous year. In the early
spring samples, green material is primarily very short leaves of winter ros-
ettes of perennial plants and thin blades of cool season annual grasses.
Grazing cattle also have difficulty selecting the green material from the
DEAD in very early spring and consequently, prefer green material from sites
where DEAD material has been removed by heavy grazing, burning, or mowing.
Watershed grazing distribution can therefore be manipulated at this time by
judicious use of fire, mowing, and/or fertilization.
The lowest values of N, P, and K in DEAD were in late winter and late
summer. DEAD material during these periods has been subjected to a signif-
icant period of leaching. The effect of leaching is also indicated by the
consistently low values of N in DEAD material collected in 1978. Rainfall
in the spring and early summer of 1978 was greater than in 1976 or 1977.
Phosphorus is less mobile than N and 1978 P values for DEAD material did not
reflect the effect of higher rainfall leaching. Potassium (K) is very mobile
and was apparently influenced more by species composition at a particular
sampling date than by a difference in annual leaching by rainfall.
Except for the late winter 1978 sample, there were no significant
(P<0.05) differences in ASH contents due to sampling date (Table 29). The
range in ASH content was only about 2% for all sampling date averages other
than the value of 11.9% for STANDING DEAD collected on 28 March 1978. The
reason for the relatively high ASH content in March 1978 was not apparent.
The average ASH content for all 17 sampling dates was 8.4% with a standard
error of 0.07%.
ADF values ranged from a low of about 45% in the fall of 1976 and 1977
to a high of 54% in early June, 1977. The overall average for ADF in STANDING
DEAD was 50.7% with a standard error of 0.6%. In general, ADF values were
lowest in samples containing the highest percentage of recent DEAD. No other
trends were evident.
ADL values varied relatively more widely than values of ASH, ADF, and
CEL. The average ADL value was 12.8% with a standard error of 0.8%. ADL
values ranged from 9.0% to 17.5% with no consistent trend due to season of
sample collection.
CEL values varied to about the same degree as did ADF values, but the
variation with season was not as consistent as for ADF values. Values for
CEL in STANDING DEAD ranged from 32.5% to 39.7% with a mean of 36.2% and a
standard error of 0.8%.
DMD values varied widely (i.e., 8.7% to 42.5%) between sampling dates
and within samples per sampling date. Generally, DMD values were highest
when the samples contained relatively high proportions of recent DEAD or un-
separated LIVE material. The lowest values were for samples collect in late
winter and mid summer. Low DMD values for STANDING DEAD during the winter
when there is little green forage to be selected by grazing cattle indicates
most of the forage ingested is passed through the animal and deposited on
the watershed as dung.
141
-------
rv>
TABLE 29. RANK ORDER BY SAMPLING DATE AND ASH, ACID-DETERGENT FIBER (ADF), ACID-DETERGENT LIGNIN (ADL),
CELLULOSE (CEL) CONTENTS (%) AND DRY MATTER DIGESTIBILIT (DMD, %) IN STANDING DEAD VEGETATION
ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
RANK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
5f±SE
DAY
8148^
8205
7160
8290
7130
8233
7192
7220
7312
8050
8120
7275
7250
8176
8254
8017
7347
-_
--
ASH
11.9.2/
9.3b
9.3b
8.8b
8.8b
8.6b
8.3b
8. Ob
8. Ob
7.7b
7.7b
7.7b
7.6b
7.5b
7.5b
7.4b
7. Ob
--
--
__
--
--
8.4±0.7
DAY
7220
8050
7275
7192
6183
7250
6163
6262
8148
6234
8205
8120
8290
6206
6290
8254
8233
7312
8017
6320
8176
7160
6346
7347
ADF
54. 2a
53. Sab
53.2ab
53. lab
53.0ab
53.0ab
52. Sab
52.5ab
52.1abc
52.0abc
51.9abc
51.9bcd
51.3bcd
51.1bcd
50.9bcde
50.9bcde
50.3cde
49.8cde
49.8cde
49.5de
48.7ef
47. Of
45. 3g
45. Ig
50.7±0.6
DAY
6206
8233
7312
6320
8120
7275
8017
7250
6290
6163
8176
8254
7347
6183
8205
6262
6234
8148
8290
6346
8050
7220
7192
7160
ADL
17. 5a
14.9b
14.8bc
14.0bc
14.0bcd
13.9bcd
13.8bcd
13.5bcd
13.3bcd
13.1bcd
IS.Obcd
12.9bcd
12.7bcd
12.7bcd
12.6bcd
12.3cd
12.3cd
11.6cd
11.5cd
ll.Scd
10.8cde
10.7cde
lO.lde
9.0e
12.8±0.8
DAY
8050
6163
8176
6290
8205
7220
6262
6234
7192
6320
6206
8254
8120
7250
8290
8148
7275
8233
8017
6183
7160
7347
6346
7312
CEL
39. 7a
39. 3a
38.7ab
38.1abc
38.0abc
37.9abcd
37.8abcd
37.5abcd
37.3abcde
37.2abcde
37.0abcde
36.3abcde
36.1abcde
35.9bcde
35.8bcde
35.6bcde
35.5bcde
35.4cde
35.0cde
34.4de
34. le
33. 9e
33. 7e
32. 5e
36.2±0.8
DAY
7347
6346
7160
8254
7312
7275
7250
6290
8017
8176
8290
8233
7220
8205
6320
8120
7192
8050
8148
6262
__
__
DMD
42. 5a
30. 7b
29.6bc
26.2cd
24.6de
23.5de
22.3ef
22.1efg
22.0efg
21.6efg
21.3efg
20.4efg
20.3efgh
18.7fgh
IS.lfgh
17.8gh
16.9gh
15. 8h
15. Oh
8.71
_
_-
--
22.1±1.4
I/Plant i/oav Ha + o « = 1Q7fl- flIAft =1/10 Ha./c a-F+av 1 Mnw 1077 U-in+nv = fini-IIK.
2/Spring = 136-211; Early Summer = 212-242; Summer = 243-304; Fall = 305-365.
Those values in the same column followed by the same letter are not signifi
0.05 level.
significantly different at the
-------
Chemical Interrelationships
No two chemical components in LIVE or STANDING DEAD were highly corre-
lated (Table 30) when all samples were used in the correlation analyses. All
correlation coefficients were less than 0.60. Correlations were no greater
in LIVE than in DEAD. Consequently, no chemical component was judged to be
a good indicator of any other component in LIVE or DEAD when samples include
a high degree of variation in species composition, growing conditions, percent
recent DEAD and differential effects of weathering on different chemical com-
ponents.
The literature offers many examples of close correlation between many
of the chemical components listed in Table 30. However, the close correla-
tions usually occurred when the vegetation analyzed varied only in one or
two factors, such as phenology in the same year, rate of fertilization or
stemrleaf ratio in the same species.
More detailed analyses of these data do show that high correlations be-
tween various chemical components do exist (Kautzsch 1978, Ball 1980). As
indicated, correlation coefficients were higher when analyzed were restricted
to similar seasons across years or to seasons within the same year.
Although correlations were not high under the wide range of conditions,
the large number of samples and wide range of conditions do support certain
generalities. Those chemical components which decrease with advancing pheno-
logical stage and are leached by weathering (i.e., N, P, & K) were correlated
within the range of correlation coefficients of 0.41 to 0.56. The structural
carbohydrates, primarily ADF and CEL, were directly correlated with each other
and inversely correlated with N, P, and K. DMD was directly related to N,
P, and K and inversely related to structural carbohydrates.
Chemical Yield (Biomass X Content)
The nitrogen yield in GROUND LITTER averaged 28.4 kg/ha and ranged from
14.5 kg/ha in the spring to 42.2 kg/ha in early fall in a 12-month period
(Table 31). GROUND LITTER N yield was not significantly different at the
0.05 level between early May and the mid winter collection date. The low N
yield in late winter and very early spring was due primarily to the low levels
of GROUND LITTER biomass at this time.
STANDING LITTER N yield averaged 10.7 kg/ha for 29 collection dates and
ranged from a low of about 6.0 kg/ha to a high of 23.3 kg/ha in late fall.
The relatively high values in late fall were due to the high N content in
unseparated LIVE and recent DEAD at this time. In general, N is easily
leached by weathering and STANDING DEAD vegetation contributed only a small
portion of the total N yield.
In 1976, the LIVE N yield averaged about 15 kg/ha between mid April and
mid September. LIVE N yield was highest in early summer at about the time
of peak LIVE biomass. Annual averages were not suitable for comparisons
because of differences in the number and dates of collection periods. How-
ever, LIVE vegetation during the growing season contributed more N yield than
143
-------
TABLE 30. CORRELATION COEFFICIENTS^ MATRIX FOR CHEMICAL COMPONENTS (%) IN LIVE (L) AND IN STANDING
DEAD (D) VEGETATION ON A TALLGRASS PRAIRIE GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA,
1976-78
Chemical Components
Component
N
P
K
CA
ASH
ADF
ADL
CEL
DMD
(L)
(D)
(L)
(D)
(L)
(D)
(L)
(D)
(L)
(D)
(L)
(D)
(L)
(D)
(L)
(D)
(L)
(D)
Mean P K CA ASH
1.46 +0.41 +0.56 +0.14 +0.11
0.84 +0.52 +0.47 +0.40 +0.24
0.11 +0.46 +0.10 +0.25
0.05 +0.45 +0.30 +0.10
1.45 +0.23 +0.35
0.36 +0.22 -0.01
0.58 +0.24
0.46 +0.07
7.6
8.5
39.8
51.0
10.4
13.1
29.9
36.4
45.8
21.4
ADF
-0.10
-0.28
-0.03
-0.31
-0.20
-0.42
-0.24
-0.05
-0.26
0.00
ADL
+0.08
+0.17
+0.05
-0.03
-0.08
-0.03
+0.01
+0.10
-0.17
-0.18
+0.44
+0.01
CEL
-0.32
-0.31
+0.30
-0.28
-0.19
-0.24
-0.30
-0.13
-0.16
-0.54
+0.23
+0.37
-0.23
+0.02
DMD
+0.34
+0.36
+0.30
+0.33
+0.40
+0.51
+0.24
+0.15
+0.21
+0.01
-0.41
-0.52
-0.20
-0.03
-0.53
-0.46
'Number of samples for LIVE:
Number of samples for DEAD:
P 0.05 if r 0.12.
N, P, K and CA (450); ASH (240); ADF, ADL and CEL (385); DMD (325),
N, P, K and CA (970); ASH (450); ADF, ADL and CEL (610); DMD (545),
-------
TABLE 31. AVERAGE (25 SAMPLES/DAY) NITROGEN YIELD (KG/HA) IN ABOVE-
GROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Day
6163^
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
Mean
Ground
Litter
14. 5c-7
27.4abc
28.0abc
37.5ab
33.5abc
32.9abc
42. 2a
26.1abc
27.2abc
31.7abc
22.3abc
17.9bc5/
2J
__
__
__
~
__
--
28.4
Vegetation
Standing
Dead
10.5efgh
10.9defgh
12.3cdef
10.6egh
9.7efgh
9.9efgh
11.5defg
23. 3a
18. 6b
13.2cde
16.6bc
8.5efgh
12.5cdef
ll.ldefgh
5.6h
6. Oh
__
7.1gh
15.5bcd
ll.Odefgh
8.8efgh
10.5efgh
7.1gh
6.1h
7.0gh
7.6fgh
6.8gh
7.5fgh
__
10.4efqh
10.7
Component
Live
7.3b
12. Ob
23. 2a
21. Oa
12.2b
14.3b
13.9
A /
X = 14.8 -'
__
__
--
21. 5a
17.5ab
13. 8b
__
15.06
__
X = 16.9
--
9.0c
13. Ib
17.7a
16. 5a
17. 2a
8.7c
8.0c
X = 12.9
Total-7
32.3cd
51.2abc
63. 5a
69. Oa
55.4abc
57.0ab
67. 5a
49.3abcd
45.7abcd
45.5abcd
38.9bcd
26.3d
__
--
__
__
__
__
--
--
--
__
--
--
--
__
--
50.2
Ground Litter + Standing Dead + Live.
|^Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
Those values in the same column followed by the same letter are not
4,significantly different at the 0.05 level.
T/Annual mean.
-/Chemical analysis not conducted; small, but variable amounts of Live
included in Standing Dead 6346-7160 and 7347-8148.
145
-------
did STANDING LITTER and less than did GROUND LITTER. Although Dung biomass
was not separated from plant GROUND LITTER, it can be expected that Dung in
the GROUND LITTER contributed a significant portion of the GROUND LITTER N
yield.
In the 12-month period from April 1976 to March 1975, Total N yield aver-
aged about 50 kg/ha and ranged from a low in the winter to a high in the sum-
mer. Although ground cover and protection from runoff is lowest in late win-
ter, the watershed N load factor is also lowest at this time. Therefore,
the greatest danger of nonpoint pollution in late winter and early spring on
rangeland grazed by livestock is probably the direct movement of dung via
overland flow. Compared to that on other kinds of land and land uses, the
Total N yield on tallgrass prairie moderately grazed by cattle is relatively
low. Although similar research was not conducted on this watershed, research
by White (1973) indicates only a small portion of the Total N yield would be
leached and transported into steamflow on a tallgrass prairie watershed.
The relationships between phosphorus (P) yield in GROUND LITTER, STAND-
ING DEAD, LIVE and Total (Table 32) were similar to those for N yield. How-
ever, Total P yield was only about 3 kg/ha as compared to the Total N yield
of 50 kg/ha. Since P content is directly correlated with N content, trends
in P yield through the 12-month period were similar to those in N yield.
Compared to N and P, potassium (K) is highly mobile and easily leached
from nonliving plant material. Consequently, the K yield was relatively low
in GROUND LITTER and STANDING DEAD as compared to that in LIVE vegetation
(Table 33). The Total K yield averaged about 16 kg/ha for the 12-month per-
iod of sampling and analyses of GROUND LITTER, STANDING DEAD, and LIVE vege-
tation. K yield was relatively consistent in GROUND LITTER, but highly var-
iable in STANDING DEAD and LIVE vegetation. When the K yields in STANDING
DEAD for 6346, 7347, and 8343 are compared, it can be easily seen that the
unseparated LIVE in the 6346 and 7347 collection periods contributed most of
the K yield in STANDING DEAD at these times.
GROUND LITTER contributed more than half of the Total calcium (CA) yield
(Table 34). Although CA yield differences between collection dates were sig-
nificant at the 0.05 level, trends were not apparent. CA yield in GROUND
LITTER averaged about 16 kg/ha and ranged from 8.3 kg/ha to 29.1 kg/ha. Since
GROUND LITTER CA content was relatively stable (Figure 69, p. 134), much of
the lower CA yield in late winter was due to low GROUND LITTER biomass at
this time.
STANDING DEAD CA yields were relatively consistent over time ranging
from a low of 1.8 kg/ha to a high of 9.5 kg/ha. Most other low values for
CA yield were about 3 to 4 kg/ha. CA content was somewhat higher in LIVE
vegetation than in STANDING DEAD. Therefore, the highest values for CA yield
in STANDING DEAD were in the late fall of 1976 and 1977 when STANDING DEAD
samples contained unseparated LIVE vegetation. LIVE CA yields differed sig-
nificantly with years, but most of the differences were due to differences
in LIVE biomass.
146
-------
TABLE 32. AVERAGE (25 SAMPLES/DAY) PHOSPHORUS YIELD (KG/HA) IN ABOVE-
GROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Day
61622/
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
Mean
Ground
Litter
0.92bi/
2!54ab
1.97ab
3.08a
1.96ab
1.99ab
2.69ab
1.71ab
1.45ab
1.68ab
1.93ab
1.07b 5/
2f
__
__
--
._
__
__
__
_-
--
--
-
1.92
Vegetation
Standing
Dead
0.57cde
0.59cde
0.58cde
0.44de
0.43de
0.53cde
0.57cde
1.18a
0.92ab
0.56cde
0.62cd
0.43de
0.92ab
0.35de
0.27e
0.29e
_-
0.32de
1.12a
1.21a
0.47cde
0.40de
0.40de
0.36de
0.52cde
0.54cde
0.41de
0.42de
__
0.78bc
0.58
Component
Live
0.55d
0.99b
1.44a
0.95bc
0.68cd
0.92bc
0.85bc
__
^ = 0.91 -'
__
1.04b
1.36a
0.82b
__
1.06b
__
I = 1.07
__
--
__
0.86
1.02
1.33
1.28
1.42
0.73
1.37
(P<0.20)
X = 1.14
Total-^/
2.04c
4.21ab
3.99ab
4.46a
3.07abc
3.33abc
4.12ab
2.89abc
2.37bc
2.30bc
2.55abc
1.50c
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
3.07
_/ £v«/\i tin A 1 -1+ + 0V* X C+-^r*/^-irtrt HA a/4 J. 1 l\tr\
j/Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
-'Those values in the same column followed by the same letter are not
^.significantly different at the 0.05 level.
i/Annual mean.
'Chemical analysis not conducted; small, but variable amounts of Live
included in Standing Dead 6346-7160 and 7347-8148.
147
-------
TABLE 33. AVERAGE (25 SAMPLES/DAY) POTASSIUM YIELD (KG/HA) IN ABOVE-
GROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Vegetation Component
Day
6163^/
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
Mean
Ground
Litter
2.3b &
5.6ab
5.4ab
6.4a
5. Sab
5.3ab
7.4a
4.9ab
5.7ab
7.3a
4.6ab
4.1ab5/
2J
--
--
5-4
Standing
Dead
1.4J
2\7j
2.3hij
3.4efghij
S.lfghij
2.9fghij
4.2efghi
lO.Oab
7.3cd
3.2fghij
2.6ghij
1.2J
4.9efg
2.7ghij
2.6ghij
3.1fghij
--
4.4efgh
11. 2a
5.5de
2.6ghij
1.4j
1.91J
8.7bc
2.8fghij
S.Ofghij
5.1ef
S.Ofghij
__
2.9fqhij
3.9
Live
5.9c
10. Ob
17. 7a
17.5a
lO.Ob
13. 8b
11. 4b
4/
X = 12.3
15.4ab
19. 7a
13. 4b
--
16.4ab
X = 16.2
--
10. Oc
15. 8b
24. 2a
24. 8a
22. 9a
11.2bc
8.9c
X = 16.8
Total^/
9.5hij
17.4def
25.4ab
27.2a
18.6cde
21.3bcd
23.0abc
14.9efg
13.0fgh
10.6ghi
7.2ij
5.3J
_.
--
--
--
__
--
..
--
_
__
_.
__
--
16.1
i/Ground Litter + Standing Dead + Live.
4/Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
Those values in the same column followed by the same letter are not
./significantly different at the 0.05 level.
gyAnnual Mean.
-'Chemical analysis not conducted; small, but variable amounts of Live
included in Standing Dead 6346-7160 and 7347-8148.
148
-------
TABLE 34. AVERAGE (25 SAMPLES/DAY) CALCIUM YIELD (KG/HA) IN ABOVE-
GROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Day
6163^/
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
Mean
Ground
Litter
8.3t>3y
15!4ab
17.9ab
21.2ab
16.9ab
20. lab
29. la
13. Ib
14.9ab
13. 5b
8.6b
10.8br,
>_ 2J
__
__
--
"1373"
Vegetation
Standing
Dead
6.2bcdef
6.3bcdef
6.0cdefg
5.4defgh
6.3bcdef
6.0bcdefg
6.6bcde
8.6ab
9.5a
7.8abcd
8.2abc
4.5efgh
6.7bcde
4.2efghi
3.2ghi
3.2ghi
1.81
8.3ab
6.4bcdef
6.3bcdef
5.4cdefgh
4.3efghi
3.7fghi
3.6fghi
4. lefghi
4.6efgh
5.2defgh
6.7defqh
5.7
Component
Live
1.5d
3.6cd
7.4a
7.2a
4.3bc
6.8a
6.2ab
A "~ D . *5 ^~
__
__
--
__
5.4b
S.Oab
6.7ab
9.3a
__
I = 7.3
--
2.6c
S.lbc
9.6a
10. 5a
10.6a
6.1b
5.4bc
I = 7.1
To tal-^
16.0cd
25.7bcd
31.2abc
33. Sab
27.6bcd
30.5bcd
42. 9a
21.7bcd
24.5bcd
20.8bcd
16.8cd
15.3d
__
__
__
__
_.
--
--
__
--
__
--
25.5
i/Ground Litter + Standing Dead + Live.
i^Plant year date: 6 = 1976; 6163 = 163 day after 1 Nov 75.
Those values in the same" column followed by the same letter are not
./significantly different at the 0.05 level.
I/Annual Mean.
'Chemical analysis not conducted; small, but variable amounts of Live
included in Standing Dead 6346-7160 and 7347-8148.
149
-------
In summary, chemical yields were 50 kg N/ha, 25 kg CA/ha, 16 kg K/ha,
and 3 kg P/ha. GROUND LITTER, usually because of its greater biomass, pro-
duced half or more of the TOTAL nutrient yields for N, P, and CA, but only 5
kg/ha of the TOTAL 16 kg K/ha. TOTAL yields were relatively low for all nu-
trients as compared to those from highly fertilized pastures and croplands.
Total Digestible Dry Matter (DDM) yield in standing vegetation ranged
from a low of about 200 to 300 kg DDM/ha in late winter to a high of 1220 kg
DDM/ha in mid summer of 1978 (Table 35). LIVE DDM yields varied relatively
more than those in STANDING DEAD.
Digestibilities for N, P, K, and CA were not determined, but previous
research generally indicates the digestibilities of N, P, and K are directly
proportional to DMD and the N, P, and K contents. Therefore, when DMD, N,
and K are high, much of the N and K yields will move through the animal and
be deposited on the watershed in the urine. Most of the P ingested will be
deposited as dung regardless of the DMD or P content.
Range Site Differences in Chemical Composition and Yield
Differences in LIVE plant biomass due to range sites (Table 18, p. 89)
were much greater than were differences in plant chemical composition and
yield (Table 36). Only K contents were significantly (P<0.05) different due
to range site. The average K.content was slightly greater on loamy prairie
range sites (1.42%) than on shallow prairie range sites (1.34%). This would
indicate tall grasses, little bluestem and/or late summer forbs (the dominant
species classes on loamy prairie sites) were high in K or that the dominant
plant species on shallow prairie range sites were low in K.
DMD was 3.5% higher in vegetation from shallow prairie range sites than
in vegetation from loamy prairie range sites. Tallgrasses and little bluestem
usually have a lower leafrstem ratio and correspondingly lower DMD than the
dominant plants on the more xeric, shallow prairie range sites.
Differences in K, ASH, and DMD yields due to range sites were influenced
more by differences in plant biomass than by differences in chemical composi-
tion. Although the 0.1% difference in ASH in LIVE from loamy and shallow
prairie range sites was not significant at the 0.05 level, that difference
multiplied by the difference in LIVE biomass resulted in a difference of 25
kg ASH/ha (P<0.05). The DMD content (%) in LIVE from shallow prairie sites
was greater than that from loamy prairie range sites, but the greater LIVE
biomass on loamy practice range sites resulted in 80 kg/ha more DDM yield on
loamy prairie sites.
DUNG BIOMASS, DENSITY AND DEGRADATION
Based on the weight of dung collected from 30-m diameter areas around
each of 25 locations on 1 April 77, dung biomass on the watershed averaged
890 kg/ha and ranged from 60 kg/ha to 2900 kg/ ha (Table 37). There was no
measure of variation per location because dung was collected and weighed only
once during the study. The true average dung biomass on the watershed was
probably somewhat higher than 890 kg/ha because the very small particles of
150
-------
TABLE 35. AVERAGE (25 SAMPLES/DAY) DIGESTIBLE DRY MATTER YIELD
(KG/HA) IN STANDING VEGETATION ON A TALLGRASS PRAIRIE
GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Day
Standing
Dead
Vegetation Component
Live
Total
-7
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
Mean
__
llOe
130e
340c
290cd
680b
MM
__
__
__
320c
250cde
210cde
150de
230cde
210cde
790a
340c
230cde
310c
220cde
250cde
210cde
230cde
270cd
310cd
__
__
300
__
__
520b
480b
660a
540ab
""" C /
X = 550 *
__
__
__
_-
440c
670a
610ab
490bc
510bc
__
I = 550
__
__
__
260e
440d
650bc
740b
910a
580cd
260e
* = 550
__
__
630
610
1000
830
680
__
M_
320
690
880
760
720
720
790
340
230
310
220
510
650
880
1010
1220
__
__
Ground Litter + Standing Dead + Live.
4)Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
Chemical analysis not conducted; small, but variable amounts of Live
./included in Standing Dead 6346-7160 and 7347-8148.
Those values in the same column followed by the same letter are not
5/significantly different at the 0.05 level.
Annual mean.
151
-------
TABLE 36. LIVE PLANT CHEMICAL COMPOSITION (%) AND YIELD (KG/HA),
CONTENT (%) X BIOMASS (KG/HA) ON LOAMY AND SHALLOW PRAIRIE
RANGE SITES ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY
CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Composition (%)
Chemical
Component
N
P
K
CA
ASH^/
DMD
ADF
ADL
CEL
Range Site
Loamy
1.40
0.101
1.42
0.55
7.5
44.1
40.1
10.4
30.1
Shallow
1.47
0.105
1.34
0.58
7.4
47.6
39.7
10.3
29.7
pi/
0.24
0.48
*
0.11
0.52
*
0.52
0.85
0.27
Yield (kg/ha)
Range Site
Loamy
15.1
1.01
16.0
6.6
106.0
580.0
Shallow
13.7
0.99
12.8
6.1
81.0
500.0
P
0.12
0.81
*
0.32
*
*
^/Probability level ( *=P<0.05)
determined only in 1977 and 1978.
152
-------
TABLE 37. RANK ORDER BY LOCATION FOR DUNG BIOMASS (KG/HA}. OVEN-DRY)
AND DUNG PAT DENSITY (NO./HA) PRE-DUNG-REMOVAL^ AND FOR
DUNG PAT DENSITY (NO./HA) POST-DUNG REMOVAL ON A TALLGRASS
PRAIRIE WATERSHED GRAZED BY CATTLE IN NORTH CENTRAL
OKLAHOMA, 1976-78
Rank
B1omass(kg/ha)
Loca- Pre-
tion Removal
Density (No./ha)
Loca- Pre- o/ Loca- Post- 3/
tion Removal-/ tion Removal-'
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
29 $
11 B
28 C
12 C
6 D
24 D
5 D
3 D
1 D
2 E
27 E
7 E
15 E
4 E
9 E
23 E
19 E
20 E
10 F
18 F
14 F
16 F
13 F
22 F
21 F
2900
2180
1790
1600
1390
1310
1270
1200
1100
850
840
840
810
810
730
690
520
500
340
270
220
90
90
80
60
29 A
11 B
28 B
12 B
6 C
3 D
24 D
5 E
9 F
27 F
1 G
4 G
23 G
7 H
2 H
15 I
19 I
10 J
20 K
16 K
18 L
21 L
22 M
13 M
14 N
7360 a^/
6130 b
5950 b
5870 b
5580 be
5270 be
5060 bed
4770 cde
4500 cdef
4470 cdef
4140 def
4060 def
3900 efq
3460 fgh
3450 fqh
2870 gh
2710 hi
2400 hij
1680 ijk
1600 jk
1170 kl
1120 kl
780 kl
670 kl
450 1
12 A
24 B
11 B
27 C
5 C
6 C
29 C
9 D
28 D
23 E
4 E
3 E
18 E
15 F
2 F
1 G
16 G
7 G '
20 H
19 I
10 I
13 I
14 J
21 J
22 K
4010 a
3540 a
3400 a
2500 b
2470 b
2440 b
2380 b
2030 be
2020 be
1870 bed
1840 bed
1810 bcde
1730 bcde
1250 cdef
1220 cdef
1050 defg
1050 defg
940 efqh
820 fqh-
610 fgh
570 fgh
510 fqh
350 fgh
310 qh
100 h
X±SE
890±140
3580±390
1630±210
V
f/Average of 13 sampling dates, 4/76-3/77.
^Average of 17 sampling dates, 4/77-10/78.
Those location numbers in the same column followed by the same upper
case letter were determined by SAS79 cluster analysis (Helwig and
5/Council 1979) to be within relatively homogeneous clusters.
-'Those means in the same column followed by the same lower case letter
are not significantly different at the 0.05 level.
153
-------
dung incorporated in plant ground litter were not collected. However, those
particles are not considered significant in terms of additional weight nor
as a source off potential pollution. Entrapment by plant ground litter
should prevent movement by overland flow of runoff.
The average effective duration of dung biomass on the watershed is esti-
mated to be about two years. The long-term stocking rate on a yearlong basis
was estimated to be about 0.25 a.u./ha. During the 1976-78 study period,
the yearlong average stocking rate was calculated to be 0.27 a.u./ha. The
average daily dung deposition rate was calculated in the section on livestock
grazing to be about 5.0 kg/day/a.u. Therefore, the annual dung deposition
is estimated to be 460 kg/ha (0.25 a.u./ha X 5.0 kg/day/a.u. X 365 days/yr).
Since the average dung biomass on the watershed was estimated to be 900
kg/ha and the annual deposition rate was estimated to be 460 kg/ha, the aver-
age weight loss of dung biomass is estimated to be 50% per year. The actual
weight loss rate is no doubt curvilinear as a function over time and is prob-
ably asymptotic since the weight loss would be greatest initially.
Lussenhop et al. (1982) reported that nitrogen fertilization and irriga-
tion on an arid grassland in Colorado greatly increased the rate of dung dis-
appearance by increasing decomposer activity. The effect of nitrogen fertil-
ization on dung disappearance in the tallgrass prairie should also be studied
as a means of speeding nutrient cycling and decreasing the dung biomass sus-
ceptible to movement by overland flow. We observed that dung pats attacked
by dung beetles soon after deposition were rapidly disintegrated. However,
other dung pats with no dung beetle activity soon after deposition were ob-
served to persist intact throughout the duration of a 450-day observation
period. In humid grasslands, it is fragmentation rather than decomposition
that results in rapid loss of dung (Lussenhop et al. 1982).
Cluster analysis indicated about six groups of locations with similar
dung biomass values (Table 37). The range within each group was about 200
to 350 kg/ha. Nine locations had higher than average dung biomass values
and 16 locations had lower than average values.
The dung distribution by weight is also shown in Figure 70. The loca-
tions with the greatest dung biomass were all along the upper slopes of the
watershed. Five of the six locations with the greatest dung biomass were on
soils with a sandy loam surface horizon. Since cattle usually defecate after
rising from their bedground, these areas may be preferred bedgrounds and rest-
ing areas. Locations 5 and 6 also serve as shading areas. Cattle may prefer
sandy soils for bedgrounds in the winter since sandy soils are drier and
warmer than are fine-textured soils with a higher soil water-holding capacity.
Another factor affecting dung distribution may be a slower rate of decom-
position on sandy soils. Drier soils with lower soil fertility, lower soil
water content and less standing vegetation and ground litter would be expected
to have lower levels of metabolic activity by decomposer microorganisms.
The ranking of locations on the basis of dung pat density prior to dung
removal showed a rank order similar to that for dung distribution by weight
154
-------
Dung Biomass
(kg/ha)
3000
2000
1000
Intnnt
" = Acctu Hani
iFuei
RKOriing Main Gagt
T »mil SOJIBI sralion
* Tiomit srotloa
\30ll IBtnSICtiM
ENVIRONMENTAL RESEARCH WATERSHED
AGRICULTURAL EXPERIMENT STATION
OKLAHOMA STATE UNIVERSITY
Kl/4 SEC Jl ««0 «I/«S£C JZ
rzoK.RiE.noaLE cou»rr,oiL«
Figure 70. Dung biomass (kg/ha) distribution on a tallgrass
prairie watershed grazed by cattle in North
Central Oklahoma.
155
-------
(Table 37). The simple linear correlation coefficient between dung biomass
per location and dung pat density per location was +0.93. The regression
coefficient of +0.33 indicates the average dung pat weighed about 0.33 kg
(SE=0.03 kg).
The correlation coefficient for dung biomass prior to dung removal and
the average dung pat density per location between 1 April 77 and 9 October
78 was +0.73. Apparently, cattle changed their dung deposition habits or
the dung decomposition rate had not reached a steady state for the dung with
an average age of only 270 days. In addition, the period after dung removal
did not include the effects of an equal number of seasons. Dung deposition
distribution would be expected to vary with seasons.
The difference in accumulative dung pat density due to sampling date is
shown in Figure 71. There was not a linear increase in dung pat density over
time, primarily because the number of dung pats peaked in very early spring
and decreased during the spring and early summer of 1978. High variation in
dung pat density between locations negated between-sampling day comparisons
3000
2750
2500
2250
Jc 2000
v.
g 1750
« 1500
°- 1250
CO
= 1000
O
750
500
250
0
obc
jcdi
cde -
bed
id*
ob
abcd
abc
abc
abed
Jf
50 100 ISO 200 250 300 350 400 450 500 550 6OO
Days
Figure 71. Accumulative dung pat density (number/ha) after 1 April 77
on a tall grass prairie watershed grazed by cattle in
North Central Oklahoma. Those values followed by the
same letter are not statistically different at the
0.05 level of significance.
after mid winter of 1977-78. However, predicting dung pat density over time
with a quadratic equation greatly increased the percentage of variation in
dung pat density that was accounted for. The R2 value for the equation, Den-
sity = 518 + 3.8 Day, was 71% with a standard error of 105 dung pats per hec-
tare. The R2 value for the equation, Density = -251 + 12.0 Day - 0.0144 Day2,
156
-------
was 89% with a standard error of 68 dung pats per hectare. Plotting regres-
sion residuals against predicted values showed that the quadratic equation
underestimated the dung pat density in the summer of 1978.
Because of the high variation between locations and the relatively short
period of time after dung removal, developing an equation which best fits
these limited data may lead to premature and erroneous interpretations.
Therefore, it is recommended that a similar study should be conducted over a
period of time which allows dung density to reach and stabilize at pre-removal
levels.
Range Site Differences
Small differences in dung density and biomass due to range site (Table
38) and plots of accumulative dung density over time per location.indicated
similarities in dung deposition pre- and post-removal due to range site, but
differences in deposition distribution patterns within range sites. As indi-
cated in Table 38, dung deposition was much greater on shallow prairie range
sites than on loamy prairie range sites. Pre-removal dung density was 2610
pats/ha on loamy sites and 5070 pats/ha on shallow sites. The ratio of pre-
removal shallow prairie dung density to loamy prairie dung density was 1.94:1
indicating slightly less than twice as many dung pats on shallow sites as on
loamy sites. The ratio of pre-removal shallow prairie dung biomass to loamy
prairie dung biomass, however, was 2.69:1.
TABLE 38. AVERAGE DUNG PAT BIOMASS (KG/HA) AND DENSITY (NO./HA) ON
LOAMY PRAIRIE AND SHALLOW PRAIRIE RANGE SITES PRE- AND
POST-DUNG-REMOVAL ON A TALLGRASS PRAIRIE WATERSHED GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Sampling
Period^/
Range
Site
Loamy (N=12)
Shallow (N=9)
Mean
.pi/
Ratio (Sh:L)
Pre-removal
Density
2610
5070
3840
0.01
1.94
Biomass
540
1450
995
0.01
2.69
Post-Removal
Density
1010
2480
1745
0.01
2.46
13 Sampling dates 4/76-3/77; all dung pats removed from sampling areas
9/l April 77; 17 sampling dates 4/77-10/78.
-Probability level.
157
-------
Dung pat size and weight may be greater on shallow prairie sites if
cattle defecate greater amounts per deposition after rising from a bedground
or resting area. However, another explanation is that dung decomposition is
slower on more xeric, shallow prairie sites. This theory is also supported
to some degree by the ratio of 2.46:1 for post-removal, shallow and loamy
prairie dung densities. The post-removal dung density ratio for different
sites is more like that of the pre-removal dung biomass ratio than is that
of pre-removal dung density.
Predicting Dung Biomass and Density
Regression equations developed to predict pre-removal dung density and
biomass and post-removal dung density accounted for about 80 to 90% of the
variation (lable 39). The regression equations for pre-removal dung density
and dung biomass were very similar since pre-removal dung density and dung
biomass were highly correlated (r=+0.93). A horizon soil water and sodium
contents and MEI were inversely related to dung density and biomass, whereas
A horizon potassium content was directly related to dung density and biomass
in both equations. In general, pre-removal dung density and biomass were
greater on the warmer and more xeric sites.
A horizon potassium content was a minor, but consistent factor in all
three equations predicting dung density and dung biomass. Dung density and
dung biomass increased as A horizon potassium content increased.
Dung Deposition and Herbage Utilization
Dung deposition measures were not highly correlated with herbage utili-
zation measures (Table 40). Therefore, the locations with the higher dung
deposition values did not consistently have the higher herbage utilization
values. The magnitude of the correlation coefficients between dung deposi-
tion and DEAD utilization were about twice the magnitude of correlation coef-
ficients between dung deposition and LIVE utilization. Therefore, although
correlation coefficients were low, cattle apparently spent more time grazing
in the areas of greater dung deposition in the winter than during the growing
season. As indicated in the section on herbage utilization, DEAD utilization
was influenced primarily by abiotic site factors, whereas LIVE utilization
was influenced to a high degree by LIVE production and species composition
which were significant only during the growing season.
The relationships between dung deposition and herbage utilization may be
more apparent when the LIVE and DEAD utilization values per location in Figure
7z are compared to the dung deposition values per location shown in Figure 70,
p. 155. The highest dung deposition values were for those locations used as
bedgrounds and resting areas and where the dung decomposition rates would be
lowest. These locations coincided with the locations with a high degree of
DEAD utilization, primarily on the relatively high, wide, and flat ridgetop in
the west central portion of the watershed (Table 41). Both LIVE and DEAD
utilization were relatively low on the lower slope positions along drainage-
ways; however, LIVE utilization was frequently much higher than DEAD utiliza-
tion in these areas. Therefore, we conclude that cattle prefer to graze green
tall grass material during the growing season, but not dead tall grass material
in any season.
158
-------
en
MD
TABLE 39. REGRESSION EQUATIONS^ FOR DUNG BIOMASS (KG/HA) AND DUNG PAT DENSITY (NO./HA) PRE-DUNG
REMOVAL-7 AND FOR DUNG PAT DENSITY (NO./HA) POST-DUNG-REMOVAL ON A TALLGRASS PRAIRIE
WATERSHED GRAZED BY CATTLE IN NORTH CENTRAL OKALHOMA, 1976-78
Y1
Biomass
(Pre- removal)
X = 890 kg/ha
Range (60-2900)
R2 = 80.9
SE = 67
Density
(Pre- removal)
7 = 3580 pats/ha
Range (450-7360)
R2 = 90.0%
SE = 136
Density
(Post-removal)
7 = 1630 pats/ha
Range (100-4010)
R2 = 77.6%
SE = 10.7
bi
2925
-202
-13.3
3.02
-1.02
9450
-613
-29.2
-3.03
7.83
2300
-878
-5213
4.67
Site Factor (X..)
b
A horizon soil water
A horizon sodium
A horizon potassium .
(Moisture economy index)
b
A horizon soil water
A horizon sodium 4
(Moisture economy index)
A horizon potassium
Slope portion -f
A horizon nitrogen
A horizon potassium
Unit
%
ppm
3/ppm
%
ppm
ppm
%
ppm
% of
R2
33
26
12
10
46
19
13
12
61
9
8
r
-0.74
-0.11
+0.35
-0.63
-0.84
+0.01
-0.72
+0.33
-0.82
-0.30
+0.34
Range
Min.
6
35
230 .
(0.33r
6
35 .
(0.33r
230
1
0.001
230
(Xi)
Max.
13
123
475 .
(5.04r
13
123 ,
(5.04)4
475
3
0.188
475
. All equations and regression coefficients (b.) are significant at the 0.05 level.
*' All dung removed, dried and weighed 1 April 77.
= Aspect X Slope (%).
= Upper 1/3; 2 = Middle 1/3; 3 = Lower 1/3.
-------
TABLE 40. CORRELATION COEFFICIENTS MATRIX FOR DUNG DEPOSITION AND
HERBAGE UTILIZATION MEASURES FROM 25 LOCATIONS ON A TALL-
GRASS PRAIRIE WATERSHED GRAZED BY CATTLE IN NORTH CENTRAL
OKLAHOMA, 1976-78
DUNG^
Post- Pre-
Removal Removal
Density Biomass
DUNG (Pre: density) 0.81 0.93
DUNG (Post: density) 0.73
DUNG (Pre: biomass)
UTILIZATION (LIVE)
UTILIZATION (DEAD)
UTILIZATION^/
LIVE
0.16
0.13
0.09
DEAD
' 0.33
0.35
0.24
0.33
STDV
0.14
0.13
0.06
0.66
0.88
DUNG: Pre-removal density (pats/ha), Post-removal density (pats/ha),
Pre-removal biomass (kg/ha).
-/UTILIZATION: LIVE (%), DEAD (Standing Dead, %), STDV (Total Standing
Vegetation, %).
In summary, the most important consideration from a dung deposition and
potential pollution standpoint is not where on a watershed cattle graze, but
where they choose for bedgrounds and resting areas. The danger of dung move-
ment into steamflow appears to the greatest in the spring when aboveground
vegetation.biomass is lowest and the dung load factor and probability of run-
off are highest. Therefore, livestock grazing distribution and watershed
management practices designed to minimize potential pollution should consider
livestock behavior. Where possible, maximum standing and ground cover should
be maintained on areas receiving the greatest dung deposition. Dung decom-
position should be increased to minimize the steady-state dung biomass. Per-
sonal observations indicate birds often help speed fragmentation when undi-
gested grain, such as whole milo, passes through cattle and is available in
the dung. Dung pats attacked by birds are rapidly fragmented and incorpor-
ated into ground litter before the impervious crust hardens.
Chemical Composition Changes Over Time
Changes in nitrogen, phosphorus, potassium, and" calcium contents of dung
in place on the watershed for various periods of time were not consistent
with respect to nutrient or season of deposition (Table 42). The N contents
of dung deposited in July 1976 were more inconsistent than those deposited
at other times. The N contents in dung deposited in September 1977 changed
very little, whereas N contents in dung deposited in January and May 1978
decreased over time. Averaged over all deposition seasons, there was only a
160
-------
Utilization (%)
Live
Dead
LEGEND
Woterihid Boundory
Pond Woterthed Boundai]
noContour I
inlitmittenl Wotirvay
rr-rr ACCIU Rood
iIFtnct
Recording Rein Gog*
T Runoff Gogir.g Station
A Tioniit Station
/~\ Soil Waltr Station
ENVIROWENTM. RESEARCH WSTERSHEO
AGRICULTURAL EXPERIMENT STATION
OKLAHOMA STATE UNIVERSITY
NEI/4 SEC 31 »NO KWIMCEC 32
T20N,Rlt, KOBIE COUKTt.ClLA
Figure 72. Average (7 grazing periods) utilization (%) of LIVE
and STANDING DEAD herbage by sampling location on
a tall grass prairie watershed grazed by cattle
in North Central Oklahoma, 1976-78.
161
-------
TABLE 41. RANK ORDER BY LOCATION FOR AVERAGE (7 GRAZING PERIODS)
UTILIZATION (%) OF VEGETATION COMPONENTS ON A TALLGRASS
PRAIRIE WATERSHED GRAZED BY CATTLE IN NORTH CENTRAL
OKLAHOMA, 1976-78
Rank
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
X±SE
Loca-
tion
4A3/
3 B
15 C
13 C
28 C
2 D
6 D
7 D
18 D
14 D
16 D
1 D
5 D
24 D
23 E
12 E
29 F
27 F
20 F
10 G
9 G
19 G
11 H
22 H
21 H
LIVE
59.4
52.7
44.0
41.1
40.4
38.7
38.4
37.6
36.4
35.3
34.9
34.7
34.7
33.5
20.6
29.9
27.0
26.9
'24.4
17.7
16.9
16.9
4.4
3.4
1.7
30.5±2.9
Loca-
tion
2 A
1 A
5 A
16 B
24 B
19 B
3 B
27 B
4 C
29 C
13 C
23 C
18 D
12 D
11 E
6 F
28 F
9 G
22 G
21 H
14 H
20 H
7 H
10 H
15 I
DEAD!/
57.0
55.0
53.8
51.4
49.0
48.3
48.0
47.9
43.0
42.7
41.3
41.3
35.5
33.2
29.8
23.0
21.0
15.0
14.0
8.8
8.3
6.3
6.0
5.7
2.9
31.5±3.7
Loca-
tion
4 A
16 A
3 A
1 B
2 B
13 B
19 C
5 C
24 C
18 C
27 D
23 D
29 D
28 E
12 F
6 F
15 F
7 G
14 G
22 H
11 H
20 H
9 H
10 I
21 I
L^
50.4
48.9
48.1
45.3
45.3
42.6
40.4
40.0
39.2
37.3
34.5
33.6
32.7
28.9
25.4
23.3
22.4
20.1
19.2
15.1
14.9
14.9
13.5
11.3
11.1
30.3±2.6
-/STANDING DEAD
-/LIVE + STANDING DEAD
I/
Those location numbers in the same column followed by the same letter
were determined by SAS79 Cluster Analysis (Helwig and Council 1979)
to be within relatively homogeneous clusters.
162
-------
TABLE 42. AVERAGE CHEMICAL COMPOSITION (%) OF CATTLE DUNG DEPOSITED
IN DIFFERENT SEASONS AND COLLECTED AFTER DIFFERENT PERIODS
OF TIME ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY CATTLE
IN NORTH CENTRAL OKLAHOMA, 1976-78
Degradatio
Period
(Days)
0
15
30
60
90
120
180
24(j,
P-f
0
15
30
60
90
120
180
240
P
0
15
30
60
90
120
180
240
P
in
7/76
1.92
--
1.91
2.15
_-
1.72
1.65
2.21
0.07
0.21
__
0.24
0.27
--
0.20
0.22
0.26
0.18
0.50a
0.29b
0.27b
_-
0.20b
0.17b
0.21b
0.01
Deposition Season
7/77 9/77
NITROGEN
1.40 -1
1.39 1.33
1.44 1.23
1.43 1.35
1.75 1.42
1.50 1.47
1.38
1.24 1.44
0.23 0.51
PHOSPHORUS
O.OSc
0.30a 0.13
0.31a 0.18
0.20b 0.19
0.31a 0.24
0.20b 0.20
0.20
0.16bc 0.19
0.01 0.37
POTASSIUM
O.SOa
0.30bc 0.37a
0.27bc 0.38a
0.39ab 0.25b
0.27bc 0.26b
0.16c 0.25b
0.20b
0.22c 0.17b
0.01 0.01
1/78
1.35
__
__
1.22
1.23
1.21
1.28
1.24
. 0.67
0.16c
__
0.21ab
0.25a
0.19bc
0.15c
0.15c
0.01
0.49a
-_
--
0.30b
0.33b
0.23bc
0.14c
0.25b
0.01
5/78
2.29a3/
__
1.79b
1.75b
1.54b
__
__
0.01
0.19b
__
0.52a
0.44a
0.44a
--
__
0.01
1.15a
__
0.21b
0.23b
0.25b
__
0.01
MearA/
1.83a
1.37b
1.61ab
1.58b
1.49b
1.48b
1.44b
1.49b
0.01
O.llc
0.22ab
0.25ab
0.21bc
0.31a
0.15c
0.12c
O.Uc
0.01
0.70a
0.33b
0.29b
0.29b
0.28b
0.21bc
O.Uc
0.21bc
0.01
(Continued)
163
-------
TABLE 42 (Continued)
Degradation
Period
(Days) 7/76
Deposition Season
7/77 9/77 1/78
, , i /
5/78 Mean^
CALCIUM
0
15
30
60
90
120
180
240
P
1.39
-.-
1.27
1.44
-_
1.07
1.23
1.24
0.23
1.03
0.99
1.00
0.75
1.01
0.93
0.78
0.24
__
1.15
0.92
1.07
0.97
1.08
0.89
0.87
0.26
1.34a
__
_.
0.90b
0.93b
0.75b
0.86b
0.71b
0.01
1.48
__
1.30
1.24
1.25
__
--
0.13
1.37a
1.06bc
1.13b
l.OSb
1.04bc
0.96bc
l.OObc
0.88c
0.01
Average weighted by number of samples per deposition season and
degradation period.
'Dung sample not collected or not analyzed.
Those values in the same column followed by the same letter are not
significantly different at the 0.05 level.
-Probability level.
164
-------
slight decrease in N content over time. Essentially, those factors influenc-
ing the N content of dung at the time of deposition strongly outweigh environ-
mental factors influencing loss of N after deposition.
The phosphorus content in dung also varied due to season of deposition
and period of time subject to degradation. In general, P concentration in-
creased during the first 30 to 90 days after deposition and decreased after
about 90 days in place. Apparently, since P is relatively immobile, the
actual amount of P remains relatively constant, but other material in dung
decreases. Then, either P is mobilized and moved out of the dung or P-bearing
material is moved out of the dung. P contents due to season of deposition
did not vary as much as did N contents.
The change in potassium contents over time was much more consistent than
those of N and P contents. K content decreased rapidly in the first 15 to
30 days in place, then stabilized over the remainder of the period.
Changes in calcium content in dung over time were similar to those of K
content. However, the relative loss of CA over time was not as great as that
of K.
Changes in concentrations of structural fiber components (i.e., acid-
detergent fiber, acid-detergent lignin, and cellulose) were determined over
a 240-day degradation period for dung deposited in July 1976 (Table 43).
Fiber and lignin tended to increase over time, whereas cellulose decreased
over time.
TABLE 43. AVERAGE FIBER COMPONENTS (35) OF DUNG (0-240 DAYS) DEPOSITED
JULY 1976 ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY CATTLE
IN NORTH CENTRAL OKLAHOMA
Degradation
Period
(Days)
0
30
60
120
180
240
Acid-Detergent
Fiber
(*)
46. 8c^/
47. 5c
50. 7b
55. Oa
54. 4a
53. 9a
Acid-Detergent
Lignin
(%)
18. Ic
17.3c
21. 2a
19.0bc
20. Sab
21.7a
Cellulose
(*)
23. Oa '
21. 8b
20. 8c
18. Od
18.7d
19.4cd
Those values in the same column followed'by the same letter are not
significantly different at the 0.05 level.
165
-------
Regardless of the nutrient in question, changes in chemical concentra-
tion over time were not great. Although a certain percentage of the initial
chemical content was leached, volatilized or otherwise moved out of the dung
pat, dung decomposition appears to be affected more by fragmentation and
incorporation into the soil by decomposers.
Changes in dung pat weight over time were not determined. However, this
area of dung degradation research should be studied. Based on variation in
the degradation of different dung pats observed on the watershed, future
research will no doubt require sampling a large number of dung pats deposited
in different seasons. Weeda (1967) reported dung deposited in the fall dis-
appeared more rapidly than dung deposited in the spring or early summer.
Castle and MacDaid (1972) found dung deposited on N-fertilized pastures dis-
appeared significantly faster in July than that deposited in May.
166
-------
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172
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APPENDIX A
SOIL DESCRIPTIONS FOR WATERSHED SOILS
CLASSIFICATION AND CORRELATION OF THE SOILS OF
ENVIRONMENTAL RESEARCH WATERSHED OF NOBLE COUNTY, OKLAHOMA
The 137 acres of the Environmental Research range are located primarily
in the NW% and the NH of the SW% of Section 32, T20N, R1E, Noble County, Okla-
homa. The Soil Survey was made by personnel of project 1383 under direction
of Earl C. Nance, Soil Scientist, USDA, retired, January 1976. Also, several
students in soil morphology courses were involved with the survey.
Inclusions are a normal part of the mapping units. Where data is to be
obtained from a location, the soil should be described and named at that loca-
tion. The approximate scale of mapping is 1:7920 (or 8 inches per mile).
The upland soils on the station are developed in materials weathered
from alternating layers of shale and sandstone. Lithologic discontinuities
are common with the upper part of the solum developed in materials weathered
from sandstones and the lower part developed in materials weathered from
shales (Fenton Gray, 51383 Project Leader, 1976).
Aydelotte loam, 3 to 6 percent slopes, Soil No. 1
About half of these soils have 102-153 cm solum thickness and are out-
side the range of the series. The remainder have more than 153 cm solum
thickness to bedrock. In many areas the upper 25-50 cm of the solum is
developed from sandstone and the lower part is developed from shale.
Representative Pedon:
Al 0 - 13 cm Dark brown (7.SYR 3/2); loam; weak medium granular
structure; friable; neutral; clear smooth boundary.
Bl 13 - 25 cm ~ Brown (7.5YR 4/2); loam; moderate medium granular
structure; friable; slightly acid; abrupt smooth boundary.
Cr 25 - 28 cm Strong brown (7.SYR 5/6); fractured, bedded, para-
lithic sandstone; neutral; abrupt smooth boundary.
IIB12 28 - 36 cm Reddish brown (SYR 4/4); loam; weak fine subangular
blocky structure; friable; neutral; abrupt smooth boundary.
IIB2U 36 - 48 cm Reddish brown (2.5YR 4/4); silty clay; weak fine
blocky structure; very firm; neutral; shiny ped surfaces;
gradual smooth boundary.
IIB22t 48 - 76 cm Reddish brown (2.5YR 4/4); silty clay; weak medium
blocky structure; very firm; moderately alkaline; shiny ped
surfaces; few fine black bodies; gradual smooth boundary.
173
-------
IIB3 76 - 152 cm Red (2.SYR 4/6); silty clay; weak fine blocky
structure; very firm; moderately alkaline; very firm; shiny
ped surfaces; few fine black bodies; few gypsum crystals.
Range in characteristics: Sol urn thickness ranges from 102 to more than
153 cm. Thin paralithic beds of fractured sandstone are present in any part
of the sol urn in some areas. The Al horizon colors are dark brown (7.5YR 3/2)
or dark reddish brown (5YR 3/3). Reaction is slightly acid or neutral. The
IlB2t or B2t horizon where present, colors are reddish brown (5YR 4/4; 2.5YR
4/4). Textures are silty clay or clay. Reaction ranges from slightly acid
through mildly alkaline. The IIB3 or 83 horizon colors are reddish brown
(2.5YR 4/4) or red (2.5YR 4/6). The Cr or IlCr horizon is thin paralithic
seams of fractured sandstone and thick bedded shales. Included with these
soils in mapping are small areas of Grainola and Stoneburg soils and slick-
spot (sodium) soils.
Darnell fine sandy loam, 3 to 6 percent slopes, Soil No. 2
These soils have cambic horizons, that are close to minimal argillic
horizon in some areas.
Representative pedon
Al -- 0 - 12 cm Brown (10YR 5/3); fine sandy loam; weak fine
granular structure; very friable; slightly acid; clear smooth
boundary.
8212-40 cm Brown (7.5YR 5/4); fine sandy loam; weak fine
granular structure; very friable; medium acid; clear smooth
boundary.
Cr 40 - 51 cm -- Strong brown (7.5YR 5/6); paralithic bedded sand-
stone; fractured; roots penetrate these sandstone beds in
fractures; slightly acid.
Range in characteristics: So I urn thickness is 25 to 50 cm. Al horizon
colors are brown (10YR 5/3; 7/bYR 4/2, 4/3) very dark greyish brown (10YR
3/2) or reddish brown (5YR 4/3). Reaction is slightly or medium acid. The
B2 horizon colors are dark yellowish brown (10YR 4/4), brown (7.5YR 4/4, 5/4),
strong brown (7.5YR 5/6), reddish brown (5YR 4/4, 5/4) or yellowish red (5YR
5/6). Reaction ranges from medium acid through neutral. The Cr horizon is
bedded sandstone of varying thickness. Colors are shades of brown or red.
Included with these soils in mapping are small areas of Stephenville soils,
rock outcrops and soil similar to Darnell except the solurn has loamy sand
texture.
Darnell-Rock outcrop complex, 1 to 8 percent slopes, Soil No. 3
These soils and sandstone rock-outcrops occur in an intricate pattern
that is not practical to separate at the scale selected for mapping. Darnell
soils make up about 90 percent, rock outcrops make up about 5 percent and
other soils make up about 5 percent of the mapped area. Darnell soils in
this mapping unit typically have less than 25 cm of solum thickness and are
174
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outside the range of the series. However, the use and management of these
soils are similar to Darnell soils.
Representative Pedon
Al 0 - 15 cm Brown (7.5YR 4/4); fine sandy loam; weak fine gran-
ular structure; very friable; slightly acid; clear smooth bound-
ary.
Cr 15 - 25 cm Strong brown (7.SYR 5/6); paralithic, fractured
bedded sandstone; slightly acid, textures to sandy loam; roots
penetrate in fractures.
Range in characteristics: Solum thickness is 8 to 50 cm. The Al hor-
izon colors are brown (10YR 5/3; 7.5YR 4/2, 4/4), dark grayish brown (10YR
4/2) or reddish brown (5YR 4/3). Reaction is slightly or medium acid.
Where present, the B2 horizon colors are shades of brown or red in hues 10YR,
7.5YR or SYR. The texture is fine sandy loam and reaction ranges from medium
acid through neutral. The Cr horizon colors are shades of red or brown, frac-
tured, bedded sandstone. Rock outcrops are sandstone bedrock exposed at the
surface or protruding above the surface.
Included in mapping are small areas of Stephenville soils and soils sim-
ilar to Darnell soils except the sol urns are loamy fine sand.
Grainola loam, 0 to 3 percent slopes, Soil No. 4
The Al horizons are developed from sandstone and the IIBt horizons are
dominantly developed from shales. These soils are outside the series range
because of the Al horizon's loam texture and the reaction of the A and upper
B horizons. However, their use and management are similar to Grainola soils.
Representative Pedon
Al 0 - 7 cm Dark brown (7.SYR 3/2); loam; weak fine granular
structure; friable; slightly acid; clear smooth boundary.
IIB2H 7-20 cm Dark reddish brown (SYR 3/4); silty clay; moderate
fine blocky structure; very firm; neutral; shiny ped surfaces;
few vertical faces are coated with brown loam; clear smooth
boundary.
IIB22t 20 - 35 cm Reddish brown (SYR 4/4); silty clay; weak fine
blocky structure; very firm; mildly alkaline; shiny ped surfaces;
few vertical faces are coated with brown loam; gradual smooth
boundary.
IIB23t 35 - 46 cm Reddish brown (SYR 4/4) silty clay; weak fine blocky
structure; very firm; moderately alkaline; shiny ped surfaces;
few fine CaC03 and Fe-Mn oxide concretions; clear smooth bound-
ary.
I IBS -- 46 - 61 cm -- Reddish brown (SYR 4/4); silty clay and shale;
weak coarse blocky structure; very firm; moderately alkaline;
clear smooth boundary.
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HCr 61 - 76 cm Moderately alkaline shale with thin lens of sand-
stone; few gypsum crystals.
Range in characteristics: Sol urn thickness is typically 50 to 75 cm but
ranges 50 to 100 cm. A Cr horizon of thinly bedded sandstone is present be-
tween the Al and IIBt horizons in some areas. The Al horizon colors are dark
brown (7.5YR 3/2), dark reddish brown (5YR 3/2, 3/3, 3/4) and reddish brown
(5YR 4/3). The texture is dominantly loam; however a few areas of silty clay
loam are present. Reaction ranges from slightly acid through mildly alkaline.
The Bl horizon, where present, colors are brown (7.5YR 4/2), reddish brown
(SYR 4/4, 4/3) or yellowish red (5YR 4/6). Textures are loam or clay loam
and reaction ranges from slightly acid through neutral. The IIB2t horizon
colors are dark reddish brown (5YR 3/3, 3/4; 2.5YR 3/4), or reddish brown
(SYR 4/4; 2.5YR 4/4). Textures are clay, silty clay or silty clay loam.
Reaction ranges from slightly acid through moderately alkaline. The IIB3
horizon, where present, colors are reddish brown (SYR 4/4; 2/5YR 4/4). Tex-
tures are silty clay or clay. Reaction ranges from mildly through moderately
alkaline. The IlCr horizon is shale with thin lens of sandstone. Colors
are shades of red, brown, or gray.
Included in mapping are small areas of similar soils that have less than
51 cm of solum thickness, Lucien soils, and soils similar to Grainola except
the IIBt horizons are brown sandy clay. Also included are a few slick-spot
(sodium) soils.
Grainola loam, 3 to 6 percent slopes, Soil No. 5
The Al horizons and in some areas the upper B horizons are developed
from sandstone; and the IIBt horizons are developed from shale. These soils
are outside the series range because of the Al horizon texture and the reac-
tion of the A and upper B horizons. However their use and management are
similar to Grainola soils.
Representative Pedon
Al 0 - 12 cm Dark reddish brown (SYR 3/3); loam; weak medium
granular structure; friable; neutral; clear smooth boundary.
IIB1 12 - 23 cm Dark reddish brown (5YR 3/3); silty clay loam;
weak fine blocky structure; firm; mildly alkaline; some vertical
faces coated with loam texture; clear smooth boundary.
IIB2U 23 - 41 cm Dark reddish brown (2.SYR 3/4); silty clay; moderate
fine blocky structure; very firm; mildly alkaline; shiny ped
surfaces; gradual smooth boundary.
IIB22t 41 - 86 cm Dark reddish brown (2.SYR 3/4); silty clay; weak
medium blocky structure; very firm; moderately alkaline; shiny
ped surfaces; few seams and bodies of CaCo-; few slickensides
do not intersect; abrupt smooth boundary.
IlCr 86 - 152 cm Shales with lens of fractured hard and soft sand-
stone.
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Range in characteristics: Solum thickness is 51 to 102 cm. A Cr hor-
izon of thinly bedded, paralithic sandstone is present above the IIBt horizon
in some areas. The Al horizon colors are dark reddish brown (SYR 3/2, 3/3,
3/4), reddish brown (SYR 4/3) and dark brown (7.SYR 3/2). Reaction ranges
from slightly acid through neutral. A Bl or B2t horizon is present in some
areas. Colors are shades of brown or red. Textures are loam or clay loam
and reaction ranges from slightly acid through neutral.
The IIR1 and IIB2t horizons colors are dark reddish brown (SYR 3/3, 3/4;
2.SYR 3/4), reddish brown (SYR 4/3, 4/4; 2.SYR 4/4) or red (2.SYR 4/6). Tex-
tures are clay, silty clay or silty clay loam. Reaction ranges from slightly
acid through moderately alkaline. The B3 horizon, where present, colors are
reddish brown (SYR 4/4; 2.SYR 4/4). Textures are silty clay or clay and re-
action is mildly or moderately alkaline. The HCr horizon colors are shades
of red or brown. It is shale with thin layers of sandstone.
Included in mapping are small areas of Aydelotte, Renfrew, Stoneburg,
and Lucien soils and soils similar to Grainola with less than 51 cm solum
thickness and soils similar to Grainola except the upper, (sandstone), part
of the solum is 38 to 63 cm thick.
Lucien sandy loam, 1 to 3 percent slopes, Soil No. 6
These soils are outside the range of the series in that the solum thick-
ness is less than 25 cm or they lack a mollic epipedon. In typical areas,
the cambic horizon is close to being a minimal argil!ic horizon. However
all of these soils respond to use and management of the Lucien series.
Representative Pedon
Al 0 - 8 cm Dark brown (7.SYR 3/3); sandy loam; weak fine gran-
ular structure; very friable; slightly acid; clear smooth bound-
ary.
B21 8-18 cm Brown (7.5YR 4/4); sandy loam; weak coarse prismatic
and granular structure; friable; slightly acid; clear smooth
boundary.
B22 -- 18 - 38 cm Reddish brown (5YR 4/4); sandy loam; "weak coarse
subangular blocky structure; friable; slightly acid; few pale
brown (10YR 6/3) sandstone fragments; clear smooth boundary.
Crl 38 - 61 cm Reddish yellow (7.5YR 6/6); paralithic; fractured
sandstone; slightly acid; roots in bedding planes; diffuse
. boundary.
Cr2 61 - 84 cm Stratified reddish yellow (7.SYR 6/6) and light
brownish gray (10YR 6/2) sandstone; few roots in bedding planes.
Cr3 84 - 97 cm Stratified sandstone and thin lens of sandy clay;
no visible roots.
Range in characteristics: Solum thickness is 8 to 51 cm. The Al hori-
zon colors are dark brown (7.SYR 3/2, 3/3) or dark reddish brown (SYR 3/2,
3/3). Sandy loam is the dominant texture; however, areas of loam do occur.
Reaction is slightly or medium acid. The B2 horizon colors are brown (7.SYR
4/2, 4/2, 5/4), reddish brown (SYR 4/4; 2.5YR 4/4) or yellowish red (5YR 4/6).
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Textures are sandy loam or loam and reactions are slightly or medium acid.
The Cr horizon colors are shades of brown, red or yellow. Included in mapp-
ing are small areas of Stoneburg and Grainola soils and rockout crops.
Lucien loam, 3 to 5 percent slopes, Soil No. 7
About one-third of the Lucien soils lack thickness for mollic epipedons,
and these are outside the series range. Typically these soils are within
the range of the Lucien series.
Representative Pedon
Al -- 0 - 12 cm ~ Dark brown (7.5YR 3/2); loam; weak medium granular
structure; friable; slightly acid; thin J| inch paralithic sand-
stone at base; abrupt clear boundary.
B2 -- 12 - 33 cm Brown (7.SYR 4/4); loam; weak coarse prismatic
breaking to granular structure; friable; slightly acid; clear
smooth boundary.
Cr 33 - 63 cm Light yellowish brown (10YR 6/4); paralithic, frac-
tured bedded sandstone; neutral; roots in bedding planes.
Range in characteristics: Solum thickness is 25 to 51 cm. The Al hori-
zon colors are dark brown (7.SYR 3/2) or dark reddish brown (5YR 3/2, 3/3).
Reaction is slightly or medium acid. The B2 horizon colors are brown (7.5YR
4/2, 4/4, 5/4),'reddish brown (5YR4/4) or yellowish red (SYR 4/6). Reaction
is slightly or medium acid. The Cr horizon colors are shades of brown or
red.
Included with these soils in mapping are small areas of Stoneburg or
Grainola soils and rock outcrops. Also included are soils similar to Lucien
with less than 25 cm of sol urn thickness or lack a mollic epipedon.
Lucien loam, 5 to 8 percent slopes, Soil No. 8
These soils are typically within the range of the Lucien series.
Representative Pedon
Al 0 - 12 cm Dark brown (7.5YR 3/2); loam; weak fine granular
structure; very friable; slightly acid; clear smooth boundary.
B2 12 - 33 cm Brown (7.5YR 4/4); loam; weak medium granular
structure; friable; slightly acid; clear smooth boundary.
Cr 33 - 66 cm Brown (7.SYR 5/4); paralithic sandstone; neutral;
roots throughout upper part but confined to bedding planes in
lower part.
Range in characteristics: Solum thickness is 25 to 51 cm. The Al hori-
zon colors are dark brown (7.SYR 3/2) or dark reddish brown (5YR 3/2, 3/3).
Textures are loam or sandy loam and reactions are medium or slightly acid.
The B2 horizon colors are brown (7.5YR 4/2, 4/4, 5/4), reddish brown (5YR
4/4) or yellowish red (SYR 4/6). Textures are sandy loam or loam and reac-
tions are medium or slightly acid. The Cr horizon colors are shades of brown
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or red. Included with these soils in mapping are small areas of Zaneis or
Stoneburg soils.
Lucien - Rock outcrop complex, 8 to 30 percent slopes, Soil No. 9
These soils and sandstone rock outcrops occur in an intricate pattern
that is not practical to separate at the scale selected for mapping. Lucien
soils make up about 50 percent, rock outcrops about 30 percent and other soils
about 20 percent of the mapped area. Lucien soils in this mapping unit typi-
cally have less than 25 cm of sol urn thickness and are outside the series range.
However, the use and management of these soils will be similar to Lucien soils.
Representative Pedon
Al -- 0-7 cm Dark brown (7.5YR 3/2); sandy loam; weak fine qran-
ular structure; very friable; slightly acid; clear smooth bound-
ary.
AC -- 7 - 15 cm ~ Brown (7.5YR 4/4); sandy loam; weak fine granular
structure; very friable; slightly acid; clear smooth boundary.
Cr 15 - 33 cm Brown (7.5YR 5/4); paralithic, bedded sandstone;
few roots in bedding planes.
Range in characteristics: Sol urn thickness is typically 8 to 25 cm but
ranges from 8 to 51 cm. The Al horizon colors are dark brown (7.5YR 3/2,
3/3). Textures are dominantly sandy loam but include loam. Reaction is
slightly or medium acid. The AC horizon colors are brown (7.5YR 4/2, 4/4,
5/4). Textures are sandy loam or loam and reactions are slightly or medium
acid. The Cr horizon colors are shades of brown.
Included with these soils and rock outcrop in mapping are small areas
of Stoneburg and Grainola soils. Also included are soils gradational in
development between Lucien and Stoneburg or Grainola soils.
Renfrew loam, 3 to 5 percent slopes, Soil No. 10
These soils occur on side slopes and are developed in material weathered
from shales. These shales are interrupted by bedded sandstones of varying
thickness. These soils are outside the range of the Renfrew series because
of the B3 horizon colors. However, these soils will respond to management
like Renfrew soils.
Representative Pedon
Al 0 - 38 cm Dark brown (7.5YR 3/2); loam; moderate, medium gran-
ular structure; friable; slightly acid; clear smooth boundary.
Bl -- 38 - 58 cm Reddish brown (5YR 4/3); clay loam; moderate, medium
subangular blocky structure; firm; slightly acid; gradual smooth
boundary.
B21t 58 - 81 cm Reddish brown (5YR 4/3); silty clay; moderate, med-
ium blocky structure; very firm; mildly alkaline; clay films on
slightly darker ped surfaces; few fine Fe-Mh oxide concretions;
gradual smooth boundary.
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B22t ~ 81.- 127 cm Reddish brown.(5YR 4/4); silty clay; weak coarse .
blocky structure; very firm; moderately alkaline; clay films on
ped surfaces; few, medium CaCO- bodies; diffuse smooth boundary.
B3 127 - 158 cm ~ Reddish brown (5YR 4/4); clay loam high in sand;
few fine distinct yellowish red (5YR 5/6) mottles; weak coarse
blocky structure; very firm; moderately alkaline; few medium
CaC03 bodies.
Range in characteristics: The extent of these soils is too limited to
establish a range in characteristics. Included with these soils are small
areas of Grainola soils and slick-spot soils.
Stephenville sandy loam, 3 to 6 percent slopes, Soil No. 11
These soils are within the Stephenville series. However, their solum
thickness is typically less than normal for the series.
Representative Pedon
Al 0 - 8 cm Dark brown (7.5YR 3/2); sandy loam; weak fine gran-
ular structure; very friable; slightly acid; clear smooth bound-
ary.
A2 -- 8 - 30 cm Brown (7.SYR 5/4); sandy loam; weak fine granular
structure; very friable; medium acid; clear smooth boundary.
B2t 30 - 58 cm Reddish brown (5YR 5/4); sandy clay loam; weak
fine subangular blocky structure; firm; medium acid; clay films
on ped surfaces; clear smooth boundary.
Cr 58 - 76 cm Strong brown (7.5YR 5/6); paralithic sandstone;
roots throughout the matrix in upper part, but confined to frac-
tures and bedding planes in lower part; slightly acid.
Range in characteristics: Solum thickness is typically 51 to 76 cm but
ranges from 51 to 102 cm. The Al horizon colors are dark brown or brown
(7.5YR 3/2, 4/2). The A2 horizon colors are brown (7.5YR 4/4, 5/4) or redd-
ish brown (SYR 4/4, 5/4). Reaction is slightly or medium acid. The B2t hor-
izon colors are reddish brown (5YR 4/4, 5/4) or yellowish red (SYR 4/6).
Textures are sandy clay loam or loam and reaction is medium or slightly acid.
The B3 horizon, where present, is similar in color, texture and reaction to
the B2t horizon. The Cr horizon colors are shades of red or brown. Included
with these soils in mapping are small areas of Darnell soils and soils simi-
lar to Stephenville except the solum thickness is more than 102 cm.
Stoneburg loam, 1 to 3 percent slopes, Soil No. 12
These soils are outside the Stoneburg series range of characteristics
in that they lack mollic epipedons.
Representative Pedon
Al 0 - 16 cm Dark brown (7.5YR 3/3); loam; moderate medium
granular structure; friable; slightly acid; clear smooth bound-
ary.
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B21t 16 - 36 cm Dark brown (7.SYR 3/4); clay loam; weak medium
suhangular blocky structure; firm; slightly acid; clay films on
ped surfaces; clear smooth boundary.
B22t 36 - 53 cm Yellowish red (SYR 5/6); clay loam; weak medium
subangular blocky structure; firm; slightly acid; clay films on
ped surfaces; clear smooth boundary.
R or Cr -- 53 cm Sandstone - unable to atiqer.fnr color,_reactinn
and hardness.
Range in characteristics: Extent too small for establishing range in
characteristics. Included with these soils in mapping are small areas of
Grainola and Lucien soils and soil gradational in development between Stone-
burg and Grainola. Also included are small areas of soils similar to Stone-
burg with less than 20 inches solum thickness.
Stoneburg loam, 3 to 6 percent slopes, Soil No. 13
These soils are outside the range of Stoneburg series in that they lack
a mollic epipedon and some of the solum colors are slightly outside the series
range. However, these soils' responses to management are similar to those
of the Stoneburg soils.
Representative Pedon
Al 0 - 15 cm Dark brown (7.5YR 3/2); loam; moderate medium gran-
ular structure; friable; slightly acid; clear smooth boundary.
81 -- 15 - 31 cm Dark reddish brown (5YR 3/4); loam; weak coarse sub-
angular blocky structure; friable; slightly acid; gradual smooth
boundary.
B2t ~ 31 - 46 cm Reddish brown (SYR 4/4); clay loam; weak medium sub-
angular blocky structure; firm; slightly acid; clay films on
ped surfaces; diffuse smooth boundary.
B3 46 - 64 cm Reddish brown (5YR 4/4); loam; weak coarse subang-
ular blocky structure; firm; slightly acid; clear smooth bound-
ary.
Cr & R 64 - 100 cm ~ Yellowish red (5YR 5/6); neutral sandstone:
roots penetrate the matrix of the upper part but occur only in
fractures and bedding planes in lower part.
Range in characteristics: Solum thickness is 51 to 102 cm. The Al hor-
izon is dark brown (7.5YR 3/2, 3/3, 4/2) or dark reddish brown (5YR 3/3).
Reactions are slightly acid or neutral. The Bl horizon, where present, is
brown (7.5YR 4/4), reddish brown (5YR 4/3, 4/4) or dark reddish brown (5YR
3/3, 3/4). Textures are loam or sandy clay loam and reactions are slightly
acid or neutral. The B2t horizon colors are brown (7.5YR 4/4, 5/4) or redd-
ish brown (SYR 4/3, 4/4, 5/4; 2.5YR 4/4, 5/4). Textures are clay loam or
loam and reactions are slightly acid or neutral. The B3 horizon, where pre-
sent, has colors, textures and reactions similar to those in the B2t horizons.
The Cr horizon or R layer are bedded sandstones with colors in shades of
brown.
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Included with these soils in mapping are small areas of Aydelotte,
Lucien, Grainola, and Zaneis soils. Also included are soils that are grada-
tional in development between Stoneburg and Grainola over shales.
Stoneburg - Channel complex, 1 to 30 percent slopes, Soil No. 14
These soils and channel occur in an intricate pattern that is not prac-
tical to separate at the scale selected for mapping. They occur on drainage-
ways and are dominantly developed in materials weathered from stratified
edges of shales and sandstones. There are many soils in this mapping unit;
and most of them are outside the named series range of characteristics. Up-
land soils occur on 82 percent of the area; and their average slope is 16
percent. Floodplain soils occur on 10 percent of the area; on 0 to 1 percent
slopes. Channel (stream channels) occupy about 8 percent of the area.
The approximate composition of the mapping unit will be listed, along
with the reason those soils are outside the named series range. Stoneburg
will be the only soil described. For a description or range or engineering
interpretation of the named soils refer to the series description.
1. Stoneburg soils occur on 9 to 25, average 17 percent slopes and make up
28 percent of the mapping units. These soils lack mollic epipedons of
the Stoneburg series; and slopes exceed those allowed in the series.
However, their response to range and engineering uses are similar to
Stoneburg soils.
2. Stoneburg soils over clay occur on 18 to 25 percent slopes, average 22
percent slopes; and make up 4 percent of the mapping unit. These soils
lack mollic epipedons, slopes exceed those allowed and the lower subsoil
is more clayey than Stoneburg soils. Permeability rate is 0.06 to 0.20
inches per hour when the soil is at field capacity. Refer to the Stone-
burg series for use and management information.
3. Zaneis soils occur on 7 to 20, average 12 percent slopes; and occupy 17
percent of the area. Typically these soils lack bedrock within 153 cm
of the surface, that is present in the Zaneis soils. Refer to the Zaneis
series of use and management information.
4. Zaneis soils over clay occur on 3 to 5, average 4 percent slopes; and
occupy 6 percent of the area. Typically these soils lack bedrock within
153 cm of the surface, that is present in the Zaneis soils. The clayey,
lower subsoil is outside the series range. The permeability rate is
0.06 to 0.20 inches per hour when the soil is at field capacity. Refer
to the Zaneis series for use and management information.
5. Grainola soils occur on 15 to 25, average 21 percent slopes; and occupy
13 percent of the area. These soils are outside the series range because
of the Al horizon texture and the reaction of the Al and upper B horizons.
However, their use and management for range and engineering are similar
to Grainola soils.
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6. Lucien soils occur on 15 to 25, average 20 percent slopes and occupy 4
percent of the area. Some of the slopes exceed those allowed In the
Lucien series. Refer to the Lucien series for range and engineering
use and management information.
7. Noble soils occur on 15 to 30, average 23 percent slopes; and occupy
about 4 percent of the area. These soils are outside the series in that
they have more than 60 inches of solum thickness and slopes exceed those
allowed in the series. Refer to the Noble series for use and management
information.
8. Stephenville soils occur on 10 to 30, average 20 percent slopes; and
occupy about 4 percent of the area. The slopes are typically outside
the range of the series. Refer to the Stephenville series for range
and engineering information.
9. Aydelotte soils occur on 15 percent slopes and occupy 2 percent of the
area. The slopes are outside the series range. However, the use and
management information for range and engineering will apply to these
soils.
10. Channel (Creek channels) are approximately 1.5 to 4.0 m wide and 0.6
to 1.4 m deep. They occupy about 8 percent of the area. Slopes are 0
to 1 percent.
11. Pulaski soils occur on 0 to 1 percent flood plains. The control section,
0.25 to 1.0 m, averages sandy loam. These soils occupy about 4 percent
of the area and are within the Puluski series.
12. Port soils occur on 0 to 1 percent slopes in the flood plains. They
occupy about 4 percent of the area. The thickness of the mollic epi-
pedon is not cumulic in all areas. The control section exceeds 15 per-
cent fine sand or coarser in some areas. However their use and manage-
ment is similar to Port soils.
13. Aquic Udifluvents, fine-loamy, mixed, thermic - no known series for this
part of Oklahoma. (Tullahassee soils are similar but slightly less
clayey.) These soils occur on 0 to 1 percent flood plains; and occupy
about 2 percent of the area.
Stoneburg soils are outside the range of the series in that they lack a mol-
lic epipedon, slopes exceed the allowable range and some of the solum colors
are outside the series range. However, their use and management for range
and engineering are similar to Stoneburg soils.
Representative Pedon Stoneburg; moist colors
Al 0 - 10 cm Dark brown (7.4YR 3/2); sandy loam; weak fine
granular structure; very friable; slightly acid; clear smooth
boundary.
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81 10 - 41 cm Reddish brown (5YR4/4); sandy loam; weak coarse
prismatic structure; very friable; slightly acid; clear smooth
boundary.
B21t 41 - 64 cm Yellowish red (5YR 4/6); sandy clay loam; weak
coarse prismatic structure; friable; slightly acid; thin clay
films on ped surfaces and sand grains; gradual smooth boundary.
B22t 64 - 84 cm « Yellowish red (5YR 4/6); sandy clay loam; weak
coarse subangular blocky structure; friable; slightly acid; thin
clay films on ped surfaces; few fine black bodies; clear smooth
boundary.
R -- 84 cm - Sandstone too hard for auger to penetrate.
Range in characteristics: Solum thickness is 50 to 100 cm. The Al hor-
izon colors are dark brown (10YR 3/3; 7.SYR 3/2, 4/2, 4/3), dark reddish brown
(SYR 3/3) or reddish brown (SYR 4/3). Textures are sandy loam or loam and
reactions are slightly acid or neutral. The Bl horizon where present, colors
are brown (7.SYR 4/4, 4/3) or reddish brown (SYR 4/4). The B2t horizon col-
ors are brown (7.SYR 4/3, 4/4), reddish brown (SYR 4/4; 2.SYR 4/4) or yellow-
ish red (SYR 4/6). Textures are sandy clay loam or loam and reactions are
slightly acid or neutral.
Zaneis loam, 3 to 6 percent slopes, Soil No. 15
These soils are outside the range of the Zaneis series in that they lack
a mollic epipedon, have a clayey lower argillic horizon or solum thickness
is more than 153 cm. However these soils respond to range and agronomic use
and management similar to the Zaneis soils. For engineering use and manage-
ment refer to the Zaneis and Renfrew series; that is, use the Renfrew data
for the clayey lower argil!ic horizon.
Representation Pedon
Al 0 - 23 cm Dark brown (7.5YR 3/2); loam; weak fine granular
structure; friable; slightly acid; clear smooth boundary.
Bl 23 - 41 cm Reddish brown (5YR4/4); loam; moderate medium gran-
ular structure; friable; slightly acid; gradual smooth boundary.
B21t 41 - 59 cm Reddish brown (2.SYR 4/4); sandy clay loam; weak
coarse prismatic breaking to weak medium granular structure;
friable; slightly acid; clay films on ped surfaces; gradual
smooth boundary.
B22t 59 - 89 cm Reddish brown (2.SYR 4/4); clay loam; weak coarse
prismatic breaking to weak coarse subangular blocky structure;
firm; slightly acid; clay films on ped surfaces; few iron stains
on ped surfaces; abrupt smooth boundary.
IIB23t 89 -147 cm ~ Reddish brown (SYR 5/4); silty clay; moderate, med-
ium blocky structure; very firm; neutral; clay films on ped sur-
faces; few light brownish gray (2.5 YR 6/2) streaks and bodies
in lower part; clear smooth boundary.
HCr 147 -165 cm Reddish brown (2.SYR 5/4); bedded shale; mildly
alkaline; few roots in bedding planes.
184
-------
Range in characteristics: Sol urn thickness is 100 to more than 150 cm
and thickness to the IIBt horizon is 75 to 115 cm. The Al horizon colors
are dark brown (7.5YR 3/2, 3/3, 4/2) or dark reddish brown (SYR 3/2, 3/3).
Reactions are medium or slightly acid. The Bl horizon where present, colors
are reddish brown (5YR 4/4)'or dark reddish brown (SYR 3/4; 2.5YR 3/4). Tex-
tures are clay loam, sandy clay loam or loam. Reactions are slightly acid
or neutral. The B2t horizon colors are reddish brown (5YR 4/4; 2.5YR 4/4)
or yellowish red (SYR 4/6). Textures are sandy clay loam or clay loam.
Reactions are slightly acid or neutral. The IIBt horizon colors are reddish
brown (SYR 4/4, 5/4; 2.SYR 4/4) or yellowish red (5YR 4/6). Textures are
clay or silty clay. Reactions are neutral through moderately alkaline. In-
cluded with these soils in mapping are small areas of Stoneburg, or Lucien
soils.
TABLE A-l. EXPLANATION OF SOIL NAMES
Formative Elements in
Names of Great Groups
and Suborders
aqu
fluv
ust
hapl
pale
arg
ultic
typic
oils
alfs
ents
psamm
udic
Connotation
characteristics associated with wetness
associated with flood plains
of hot climates, usually dry summers
minimum horizon
old development
an argil lie horizon
ultimate in weathering
typical, soils which typify the central
concept of the Great Group
Mollisols
Alfisols
Entisols
sand textures
of humid climates
(Continued)
185
-------
TABLE A-l. (Continued)
arenic soils which must have surface epipedons
between 20 to 40 inches thick that have
textures of loamy fine sand or coarser
throughout
pachic soils with a surface layer in excess of 20
inches that have character!sites of a mollic
epipedon
Surface epipedons:
MollicA layer of soil more than 4 inches thick if underlain directly
by a lithic contact or more than one-third the thickness of the solum
if the solum is less than 30 inches, or more than 10 inches thick if
the solum is greater than 30 inches. It must contain at least one
percent organic matter and base saturation must be over 50 percent.
For color of the mollic epipedon, the value must be darker than 3.5
when moist and 5.5 when dry, and chroma of less than 3.5 when moist.
Structure is usually porous granular type.
Ochric Epipedons too light in color, too high in chroma, or too thin
to be mollic or any other diagnostic surface horizon, or they are both
massive and hard when dry.
Diagnostic subsurface horizons:
Argillic An illuvial horizon in which silicate clays have accumulated.
CambicA subsurface horizon which must have some evidence of pedongenic
processes at work but not strongly enough to be an argil lie or other
subsurface horizon.
Lithic contactA boundary between soil and a continuous, coherent under-
lying material with a hardness of 3 or more on the Mohs scale.
Paralithic contactDiffers from lithic in that the hardness of the
underlying material is less than 3 on the Mohs scale.
Particle-size classes for Family groupings:
Coarse loamywith less than 19 percent clay.
LoamyMore than 15 percent fine sand or coarser and between 0 and 35
percent clay.
Coarse loamyLess than 18 percent clay but less than 35 percent clay
and greater than 15 percent fine sand or coarser.
(Continued)
186
-------
TABLE A-l. (Continued)
Fine- loamy More than 18 percent clay but less than 35 percent clay and
greater than 15 percent fine sand or coarser.
Fine-siltywith more than 18 percent clay but less than 35 percent cla;
and more than 15 percent fine sand or coarser.
TABLE A-2. PROPORTION OF SOIL TYPES ON
WATERSHED
Soil
Symbol Soil Name
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Aydelotte loam, 3 to 6 percent slopes'
Darnell fine sandy loam, 3 to 6 percent
slopes
Darnell -Rock outcrop complex, 1 to 8
percent slopes
Grainola loam, 0 to 3 percent slopes
Grainola loam, 3 to 6 percent slopes'
4/
Luc i en sandy loam, 1 to 3 percent slopes
Lucien loam, 3 to 5 percent slopes
Luc i en loam, 5 to 8 percent slopes
Lucien-Rock outcrop complex, 8 to 30
percent slopes'
Renfrew loam, 3 to 5 percent slopes'
Stephenville sandy loam, 3 to 6 percent
slopes
Stoneburg loam, 1 to 3 percent slopes
Stoneburg loam, 3 to 6 percent slopes-'
Stonebujg-Channel complex, 1 to 30 percent
slopes-'
Approx.
Acreage
9.5
6.0
2.0
7.5
16.0
3.5
12.0
3.5
1.0
1.0
3.0
2.0
33.0
27.0
% Extent
7.0
4.5
1.5
5.6
11.7
2.6
9.0
2.6
0.7
0.7
2.2
1.5
24.1
20.0
(Continued)
187
-------
TABLE A-2. (Continued)
Soil Approx.
Symbol Soil Name Acreage
15
Zaneis loam, 3 to 6 percent slopes 10.0
Total 137.0
% Extent
7.5
100.0
If These soils are typically outside the Aydelotte series range in that
sol urn is 102 to 153 cm and the upper part is developed from sandstone.
However, their response to use and management are similar to Aydellote
soils.
2/ These soils are typically outside the Darnell series range in that the
solum thickness is less than 25 cm. However, their use and management
are similar to Darnell soils.
3/ These soils are typically outside the Grainola series range in that the
Al horizon is loam texture and developed in materials weathered from
sandstone; and the upper solum reaction is more acid. However, their
use and management are similar to Grainola soils.
4/ These soils are typically outside the Lucien series range in that the
solum thickness is less than 25 cm, or they lack mollic epipedon. How-
ever, their use and management are similar to Lucien soils.
Sf These soils are typically outside the Renfrew series range in that the
B3 horizon colors are 4 chroma. However, their use and management are
similar to the Renfrew soils.
6/ These soils are typically outside the Stoneburg series range in that
they lack mollic epipedons. However, their use and management are sim-
ilar to the Stoneburg soils. Series name being changed to "Coyle".
]_/ These soils are typically outside the Zaneis series range in that the
lower subsoil is clayey. However, the agronomic and range use and man-
agement are similar to Zaneis soils. For engineering use and management
refer to the Zaneis and Renfrew series.
188
-------
APPENDIX B
DISCHARGE EQUATIONS AND RATING TABLES FOR THE MAIN
RUNOOF MEASURING WEIR
Head Range (Ft) Equation for Discharge in Cfs
0 to 0.08 Q = {3.0363 + 0.89276 log H}{2.02674} H2'5
0.09 to 0.23 Q = {2.2868 + 0.20316 log H}{2.02674} H2'5
0.24 to 1.00 Q = {2.5289 + 0.58982 log H}{2.02674} H2'5
2 2.5
1.00 to 2.17 Q = {2.673 +0.38530 log H}{2.0052 H + 1.33|-j
2.18 to 5.50 Q = {2.772 +0.09156 log H}{2.0052 H + 1.33^-|2'5
189
-------
APPENDIX C
SUMMARY OF WATER ANALYSES PROCEDURES
TOC
Samples were analyzed using a Beckman Model 915 Total Organic Carbon
Analyzer equipped with a Model 215B Infrared Analyzer and a Beckman Ten-Inch
Potentiometric Recorder. This system provides rapid analysis of a micro sam-
ple of aqueous solution for determination of either of two quantities:
1. Total carbon (organic carbon plus carbon in carbonates).
2. Inorganic (i.e., carbonate) carbon.
For the determination of total organic carbon, the two analyses were
performed on successive identical samples; the desired quantity was the dif-
ference between the two values obtained. Both analyses were based on the
conversion of sample carbon into carbon dioxide by catalytic combustion or
wet chemical oxidation for measurement by the non-dispersive infrared anal-
yses.
Sample handling, preservation and procedure for analysis were taken from
EPA Manual of Methods for Chemical Analysis of Water and Wastes 1974, Organic
Carbon (Total and Dissolved) on page 236.
SUSPENDED SOLIDS
Suspended solids were analyzed according to EPA Manual for Chemical Anal-
ysis of Water and Wastes 1974, Residue, Total Non-Filterable on page 268. A
well mixed sample was filtered through a standard glass fiber filter, and
the residue retained on the filters dried to constant weight at 103-105C.
CHEMICAL OXYGEN DEMAND
Summary of Method
Organic substances in the sample were oxidized by potassium dichromate
in 50% sulfuric acid solution at reflux temperature. Silver sulfate was used
as a catalyst and mercuric sulfate was added to remove chloride interference.
The excess dichromate was titrated with standard ferrous ammonium sulfate,
using orthophenanthroline ferrous complex as an indicator.
The procedure used for this determination is found in EPA Manual of
Methods for Chemical Analysis of Water and Wastes 1974, Chemical Oxygen
Demand, pages 20 and 21. Standard Methods for the Examination of Water and
Wastewater, 14th edition, page 550 Method 508 (1976).
190
-------
Quality Check
The technique and quality of reagents were checked several times by the
technician analyzing agronomy samples from November 1978 until May 1979.
EPA assurance samples were analyzed on September 19, 1978 and November 17,
1978. Values obtained were 228.5 mg/1 and 12.8 mg/1; actual values were 231
and 15.4 mg/1, respectively. On October 24, 1978 a sample was sent to six
laboratories within the state as a routine quality check. The average value
was 70.7 mg/1 with a standard deviation of ±4.1; our value obtained was 72.7
mg/1 COD.
PHOSPHORUS
Summary of Method
Ammonium molybdate and antimony potassium tartrate react in an acid
medium with dilute solutions of phosphorus to form an antimony-phosphomoly-
bdate complex". This complex is reduced to an intensely blue-colored complex
by ascorbic acid. The color is proportional to the phosphorus concentration.
Only orthophosphate forms a blue color in this test. Polyphosphates
(and some organic phosphorus compounds) may be converted to the orthophos-
phate form by sulfuric-acid-hydrolysis. Organic phosphorus compounds may be
converted to the orthophosphate form by persulfate digestion.
Total phosphorus, as analyzed, is defined as all of the phosphorus pre-
sent in the sample, regardless of form, as measured by the persulfate diges-
tion procedure. Dissolved phosphorus, as analyzed, is defined as all of the
phosphorus present in the filtrate of a sample filtered through a phosphorus-
free filter of 0.45 micron pore size and measured by the persulfate digestion
procedure.
Procedure
The first set of samples dated November 15, 1978 were analyzed accord-
ing to EPA Manual for Chemical Analysis of Water and Wastes 1974, page 249,
Phosphorus, all forms (Single Reagent Method). The remainder of the samples
were analyzed using Hach Procedures, Chemical Lists and Glassware for Water
and Wastewater Analysis, 3rd edition, pages 2-104, Phosphate, Total, Organic
and Inorganic. This method is based on APHA Standard Methods for Examination
of Water and Wastewater, 13th edition, page 524 (1971). Samples were kept
refrigerated at 4C and analyzed within 24 hours of reception.
POTASSIUM - Total
Procedures follows method used in Methods for Chemical Analysis of Water
and Wastes (EPA-600/4-79-020) section 4.1.3 of the "Metals" unit. A 100 ml
sample was taken within 24 hours of delivery and acidified with 3 ml concen-
trated HNO,, placed in a 250 ml beaker on a warm hot plate and evaporated to
near dryness. The beaker was cooled, 3 ml of concentrated HN03 added, and
returned to hot plate with a watch glass atop the beaker and the sample di-
gested for several days with more HN03 added as needed to prevent drying out
191
-------
of sample. The beaker was cooled then 3 ml of 1:1-HCL: O added. Beaker
was warmed. Sample was then brought to original volume with 0.2N HNOg.
POTASSIUM - Suspended and Dissolved
A 50 ml sample was filtered with 0.45 gelman membrane, following the
EPA method.
Dissolved Portion -
To 50 ml sample, 3 ml concentrated HNO« added and sample stored in poly
bottle. J
Suspended Portion -
Filter membrane placed in beaker, 3 ml concentrated HMO, added, then
placed on hot plate, with a watch glass on top for reflux digestion for
several days. Additional concentrated HNO- added as needed to prevent dry-
ing. Watch glass removed, sample evaporated to near dryness, cooled, 3 ml
of 1:1-HCL:H«0 added. Sample is reheated then brought to original volume
with 0.2N HN03.
All labware used was washed with the following method:
1. Soaked for 15 minutes in hot water and Micro Cleaning Solu-
tion.
2. Rinsed 3 times with tap water.
3. Rinsed 3 times with tap. distilled water.
4. Rinsed 2 times with double distilled deionized water.
5. Rinsed 2 times with 0.2N HNO,.
6. Air dried.
Analysis was done on Varian Techtron (Model AA-5) with prepared "Fisher"
Brand Standards.
NITRATE, NITRITE, AMMONIA, AND PARTICIPATE NITROGEN
Nitrate (N0~), Nitrite (NOp and Ammonia (NH^).
Surface runoff water was centrifuged for 1 hour at 8000 g. to sediment
the suspended particles. Then 5, 10, or 25 ml of the supernatant was with-
drawn and used in a micro application of the methods cited below. In each
case a standard curve was prepared each time samples were run. Light path
was 1 cm. A Beckman Spectrophotometer (model 24) was used in all cases (in-
cluding the method described for PN).
Ammonia was analyzed on 5 ml samples following the spectrophotometric
method of Solorazano (1969). This method involves the development of the
blue color of indophenol by the reaction at high pH of ammonia, phenol and
hypochlorite. Optical density of standard samples and runoff samples was
read at 6400J.
192
-------
Nitrate was analyzed on 25 ml samples using the method of_Mullin and
Riley (1955). This method involves the reduction of NoZ to NOl in the pres-
ence of a hydrazine-copper reagent for 24 hours and color development with
1-napthylamine. Optical density of standard samples and runoff samples was
read at 5240°.
Nitrite was analyzed on 5 ml samples using the method of Strickland and
Parsons (1968). This colormetric determination involves reaction with sulf-
anilamide and color development with N - (1-napthyl) - ethylenediamine. Op-
tical density of standard samples and runoff samples was read at 5430^.
Particulate Matter (PM) and Partial!ate Nitrogen (PN)
Particulate matter and PN is defined here operationally as those mater-
ials retained by a Reeve Angel 984 H glass fiber filter (GFF). In determin-
ing PM, 50 ml was filtered through a preweighted and muffled (450C) GFF.
The filter was dried to constant weight at 105C and reweighed. The concen-
tration of PM per liter was caluclated as the difference between the filter
weight before and after filtration and drying, multipled by twenty. The PM
on the filter was analyzed for PN using the method of Holm-Hansen (1968).
The filter was digested in a mixture of Se-H-SO. (essentially a Kjeldahl
digestion solution) for 2 hours at 250C in a test tube. After cooling, the
contents of the tubes were made alkaline, cooled and centrifuged. The super-
natant was drawn off, placed in another clean, test tube and ninhydrin-hydrin-
dant in mixture was used to complex with NH. and develop color. Optical
densities were corrected for N remaining in the muffled filters by running
blank filters.
193
-------
APPENDIX D
DAILY METEOROLOGICAL AND RUNOFF DATA
TABLE D-l. DAILY METEOROLOGICAL AND RUNOFF DATA FOR APRIL, 1976
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air T
Max
°C
22.2
27.8
21.1
18.3
22.2
24.4
23.3
25.0
22.2
25.5
25.5
26.1
23.9
26.7
23.9
24.4
20.5
23.3
22.2
18.3
22.8
27.2
28.3
22.8
22.2
18.9
20.5
12.8
16.7
15.5
'emo Rel Solar
Min Humid Radiation
°C % Cal /cm2
8.3
10.0
5.5
2.2
6.7
12.8
13.9
5.0
9.4
14.4
10.5
13.3
16..1
15.5
11.7
11.7
10.5
10.0
11.1
6.1
12.2
13.3
15.0
11.7
12.8
11.7
9.4
8.9
10.0
6.7
Wind
Travel
km
225
161
185
124
119
127
92
71
151
140
183
161
154
196
238
352
367
134
92
174
204
233
196
201
312
209
126
243
161
85
Pan
Evap
mm
1.8
7.4
5.8
9.1
2.0
3.0
7.9
5.1
6.6
3.0
2.5
3.3
3.0
2.3
4.1
TOTAL
Rainfall
Gage 1 Gage 2
nvn mm
8.1 9.4
10.2 10.2
8.9 8.9
5.6 5.6
5.1 4.3
20.3 19.6
3.8 3.8
62.0 61.8
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
194
-------
TABLE D-2. DAILY METEOROLOGICAL AND RUNOFF DATA FOR MAY, 1976
Air Tenio Rel Solar
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Max
°C
19.4
21.7
17.2
24.4
13.3
17.2
20.0
21.1-
25.0
22.2
17.8
18.3
20.5
20.5
17.8
21.1
22.8
23.3
24.4
24.4
26.7
26.7
26.7
24.4
23.3
19.4
20.5
26.7
30.0
29.4
22.2
Min Humid Radiation
°C % Cal/cm2
11.1
4.4
6.1
10.5
10.0
12.2
11.1
4.4
10.0
11.1
7.2
8.3
8.3
12:8
14.4
11.7
10.0
13.3
14.4
16.7
18.3
15.5
15.0
15.0
15.0
14.4
10.5
14.4
20.5
17.8
15.5
Wind
Travel
km
127
. 154
140
179
145
80
39
145
143
101
69
114
153
84
220
237
129
106
177
1B3
174
130
145
122
143
200
92
87
135
122
. 114
TOTAL
Pan Rainfall
Evap Gage 1 Gage 2
iron nun iron
11.2
4.1
3.6
4.8
2.3
3.0
1.8
0.0
3.3
12.7 12.7
6.9
3.0 27.9 25.4
6.1
2.8
4.1 2.5 2.5
5.8
6.1
7.6
11.4
5.8
1.7
6.6 15.2 15.2
5.1
1.0
1.8 21.6 21.6
4.3
6.4
7.4
3.8
1.0
79.9 77.4
Runoff
iran
0.00
0.99
0.00
0.00
0.97
1.96
195
-------
TABLE D-3. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JUNE, 1976
Air Temo Rel Solar
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Max
°C
22.2
29.4
30.5
27.2
27.8
25.5
26.1
27.2
28.9
30.0
31.1
31.7
32.2
32.7
' 30.0
30.5
32.2
32.2
25.0
27.2
30.0
30.5
29.4
31.1
29.4
30.5
32.2
35.5
37.2
35.0
Min Humid Radiation
°C % Cal /cm2
15.5
13.9
15.5
15.0
18.3
18.3
18.9
16.1
15.5
19.4
21.1
21.1
22.8
23.9
15.5
15.0
15.5
18.3
12.8
12.8
17.8
18.3
23.9
21.1
16.1
21.1
23.3
20.0
19.4
20.5
Wind
Travel
km
40
37
37
39
72
84
55
64
142
102
199
198
210
157
82
101
159
89
97
91
93
225
148
56
82
127
166
74
116
no
Pan Rainfall
Evap Gage 1 Gage 2
mm mm mm
7.6
5.1
3.0
10.7
8.1
5.3
10.9
4.3
15.0
11.9
14.0
12.4
6.6
5.8
10.9
9.1
8.9 3.8 2.5
9.9 5.1 6.4
6.6
10.4
6:9
8.1
15.0
8.6
9.4
8.4
7.4
8.4 15.2 12.7
7.4
12.7
Runoff
mm
0.00
0.00
0.00
TOTAL 24.1 21.6 0.00
196
-------
TABLE D-4. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JULY, 1976
Date
1
2
3
4
5
5
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
36.7
28.3
27.2
30.5
26.7
28.9
31.7
32.2
35.0
34.4
33.3
34.4
32.2
33.3
32.2
31.7
30.5
31.1
32.2
33.3
35.0
35.5
34.4
35.0
37.8
37.8
38.3
37.8
33.9
36.1
38.9
Temp Rel Solar
Min Humid Radiation
°C % Cal/cm2
18.3
17.8
21.1
20.0
17.8
17.2
14.4
18.9
18.3
17.8
17.8
16.1
21.1
21.1
21.7
18.3
18.3
18.3
20.0
22.2
24.4
24.4
22.8
22.8
23.3
23.3
26.7
26.1
22.2
23.3
24.4
Wind
Travel
km
172
132
169
39
132
55
130
254
106
253
146
138
103
126
145
132
121
100
222
134
145
145
126
134
158
142
79
237
100
137
145
Pan
Evap
mm
9.7
6.9
8.4
2.5
5.1
2.8
4.8
7.6
10.2
6.4
8.9
9.1
7.4
10.7
0.8
9.4
10.4
8.4
9.1
7.9
8.1
9.7
7.9
7.6
7.9
7.9
7.6
12.2
8.9
7.6
7.9
TOTAL
Rainfall
Gage 1 Gage 2 Runoff
mm mm mm
37.1 39.4 0.00
11.7 20.6 0.00
15.0 8.1 0.00
63.8 68.1 0.00
197
-------
TABLE D-5. DAILY METEOROLOGICAL AND RUNOFF DATA FOR AUGUST, 1976
Air Temo Rel Solar
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Max
8C
40.0
38.9
26.1
27.8
30.5
37.8
34.4
33.3
38.9
40.0
40.0
38.3
37.8
38.3
37.8
36.7
36.7
35.5
33.9
33.3
33.3
33.3
35.0
35.0
31.7
35.0
36.7
38.3
31.1
34.4
29.4
Min Humid Radiation
°C % . Cal/cm2
25.5
24.4
16.1
17.8
20.5
18.9
24.4
25.5
23.3
22.2
23.9
21.7
22.2
21.7
21.7
21.7
21.7
21.1
17.8
15.5
18.9
18.3
18.9
15.0
16.1
21.1
18.9
20.0
17.8
16.7
17.2
Wind
Travel
km
249
127
122
192
18
98
447
101
204
192
129
161
103
196
100
122
95
111
72
58
80
109
69
55
103
82
127
97
105
80
Pan Rainfall
Evap Gage 1 Gage 2
mm mm mm
8.9
7.6 32.3 34.8
8.4
7.4
7.9
11.4
6.4
10.4
12.4
12.4
8.1
10.4 5.1 3.8
8.6
8.1 3.6 3.6
7.4 1.5 1.3
10.4
7.6
10.2
. 9.1
6.6
8.9
10.4
6.9
8.1
9.7
7.9
8.4
9.1
9.1
4.6
8.9 8.1 9.9
TOTAL 50.6 53.4
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
198
-------
TABLE D-6. DAILY METEOROLOGICAL AND RUNOFF DATA FOR SEPTEMBER, 1976
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
26.2
28.5
37.5
36.0
35.1
26.0
31.5
31.5
27.0
29.0
28.5
27.0
22.5
26.2
29.0
28.5
30.5
25.0
20.2
17.0
16.0
21.0
28.2
Temo
Min
°C
17.5
15.5
18.2
20.9
21.5
19.5
15.1
10.2
18.0
18.6
19.2
20.2
14.0
9.5
12.2
18.0
14.0
19.0
15.2
12.3
10.8
7.5
10.2
Rel
Humid
%
74
72
65
59
54
64
74
88
78
79
77
70
56
55
59
66
74
90
79
70
60
51
Solar
Radiation
Cal/cm2
334
291
313
499
495
470
463
115
113
127
265
466
476
Wind
Travel
km
34
45
61
48
74
56
61
163
129
143
116
113
103
14
76
35
45
64
58
87
63
108
m
68
97
146
208
69
34
27
Pan
Evap
mm
4.3
4.6
7.4
7.6
7.9
7.1
7.6
6.1
6.4
6.1
7.1
6.1
5.8
4.8
5.3
7.6
8.4
7.4
11.2
7.1
7.'1
8.1
6.4
4.1
3.8
1.8
3.6
3.3
4.6
5.3
TOTAL
Rainfall
Gage 1 Gage 2
mm mm
4.8 5.3
7.1 10.4
22.9 21.3
1.5 10.2
1.5 1.5
39.4 39.6
1.0 1.3
78.2 89.6
Runoff
mm
0. 00
0.00
0.00
0.00
0.00
0.00
0.00
'0.00
199
-------
TABLE D-7. DAILY METEOROLOGICAL AND RUNOFF DATA FOR OCTOBER, 1976
Date
1
2
3
4
5
6
7
8
9
10
n
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
33.5
32.4
28.7
24.0
16.5
12.2
11.0
16.0
22.0
28.0
29.5
27.0
25.5
26.9
18.0
13.0
13.0
14.2
7.0
17.2
21.5
20.3
22.0
17.0
10.5
13.5
11.2
12.1
8.0
8.8
15.3
TemD
Min
°C
12.0
13.5
16.5
13.2
8.2
6.0
7.2
2.0
7.0
8.9
12.2
13.2
10.2
10.0
9.9
3.7
-0.1
5.4
0.8
6.9
1.5
5.2
16.0
6.1
2.6
1.0
4.0
0.7
4.2
3.7
2.8
Rel
Humid
%
52
52
61
83
78
79
66
67
62
56
54
57
62
58
54
54
62
72
58
58
55
68
87
84
76
72
75
67
93
. 91
77
Solar
Radiation
Cal/ctn2
464
412
303
197
325
122
103
411
433
428
432
422
402
402
319
393
358
125
155
392
380
245
224
98
186
304
167
317
32
98
321
Wind
Travel
km
23
182
51
220
87
166
158
23
80
119
108
106
90
439
224
100
127
116
166
64
153
285
198
299
140
175
174
61
119
60
58
Pan
Evap
mm
0.20
0.11
0.12
0.16
0.20
0.00
0.07
0.24
0.05
0.33
0.33
0.24
0.29
0.36
0.20
(1)
TOTAL
Rainfall
Gage 1 Gage 2
mm mm
0.5 0.5
9.9 8.6
1.5 1.5
0.8 0.5
0.5 0.8
25.4 25.9
1.3 2.0
39.9 39.8
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
NOTE:
1. Evaporation data not available after October 15 because pan was removed
from service to prevent damage by freezing temperatures.
200
-------
TABLE D-8. DAILY METEOROLOGICAL AND RUNOFF DATA FOR NOVEMBER, 1976
Date
1
2
3
4
5
6
7
8
9
10
n
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
18.2
22.1
15.7
7.8
15.2
23.0
12.5
15.5
23.0
17.0
8.3
2.0
2.0
1.0
2.0
1.0
17.0
22.0
20.5
15.1
8.0
9.0
12.8
19.9
18.5
17.0
1.0
-2.0
3.0
10.3
Temp
Min
c
4.0
6.0
4.1
-0.7
-1.9
4.7
1.5
1.5
5.5
4.0
-3.5
-7.0
-3.2
-1.3
-2.5
-1.1
-1.7
4.0
4.8
2.1
-1.7
-5.1
0.2
0.0
7.3
1.0
-9.0
-10.6
-11.0
-9.5
Rel
Humid
V
to
68
63
57
58
60
63
54
53
66
51
80
57
55
82
84
95
72
51
64
51
60
56
56
67
78
71
60
58
58
46
Solar
Radiation
Cal/cm2
334
330
306
339
320
317
331
314
307
306
80
252
158
75
139
68
257
291
271
276
291
280
226
277
135
242
212
245
270
270
Wind
Travel
km
95
76
100
117
143
212
47
153
106
124
148
175
72
93
76
129
55
87
85
280
63
109
93
138
290
352
436
182
113
140
Pan Rainfall
Evap Gage 1 Gage 2 Runoff
mm mm mm mm
10.2 10.2 0.00
TOTAL 10.2 10.2 0.00
201
-------
TABLE D-9. DAILY METEOROLOGICAL AND RUNOFF DATA FOR DECEMBER, 1976
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
7.8
10.2
13.0
9.3
10.8
6.9
5.5
4.5
15.0
12.0
0.0
12.1
8.5
13.5
12.0
19.0
20.5
19.0
13.0
0.2
2.0
9.8
9.0
14.5
7.9
18.4
16.5
7.2
9.2
5.0
-6.0
Temp
Min
°C
-6.0
-6.0
-2.7
-2.0
-1.2
-8.6
-11.5
-8.0
3.0
-4.0
-6.2
-2.8
-5.6
-1.0
-1.8
-2.7
1.0
1.8
0.0
-5.0
-12.0
-2.2
-4.4
2.0
-2.6
-4.0
5.0
-0.5
-5.0
-14.0
-16.0
Rel
Hunri d
V
iO
67
67
67
72
86
76
59
62
68
92
85
69
69
71
71
51
43
67
72
54
60
54
59
66
66
53
40
64
57
73
60
Solar
Radiation
Cal /cm2
101
263
256
235
99
50
220
254
249
16
70.
253
258
246
220
252
248
242
211
260
254
244
251
241
247
249
233
252
253
154
246
Wind Pan
Travel Evap
km mm
in
71
164
137
174
257
127
185
339
142
154
119
71
166
277
129
113
101
66
129
132
140
179
164
106
117
174
346
124
132
TOTAL
Rainfall
Gage 1 Gage 2 Runoff
mm mm mm
2.5 4.1 0.00
2.0 1.5 0.00
4.5 5.6 0.00
202
-------
TABLE D-10. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JANUARY, 1977
- . - _ . . . . -
Date
1
2
3
4
5
5
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
QC
-2.6
-3.0
-3.9t
l.Ot
-3.2
-0.2
11.2
2.9
-7.2t
-1.7
0.0
1.2
4.7
4.7
-5.3
10.0
-3.0
7.9
13.0
7.9
4.0
2.9
6.6
10.7
11.5
15.2
4.0
4.8
0.7
9.0
Temo
Min
c
-12.1
-5.2
-4.2t
-5.2t
-7.0
-6.2
-7.7
-13.2
-14. Ot
-15.7
-10.5
0.0
-1.3
-10.0
-13.5
-10.2
-14.3
-9.0
-8.0
-2.7
-4.1
-2.2
-3.0
-5.0
-4.1
-3.8
-11.2
-11.9
-8.2
-10.8
Rel
Humid
Of
to
54
92
98t
77t
82
89
61
83
89
65
80
92
99
83
88
61
68
66
65
56
70
87
97
74
61
61
58
59
48
57
61
Solar
Radiation
Cal/cm2
144
45
48
103
81
no
263
80
164
288
268
114
42
254
152
282
232
290
238
286
276
99
62
308
307
304
306
310
287
241
316
Wind Pan
Travel Evap
km mm
119
148
246
227
211
240
418
84
135
142
100
119
132
145
356
180
158
71
72
130
137
117
113
122
114
153
90
142
270
TOTAL
Rainfall
Gage 1 Gage 2 Runoff
mm mm mm
10.2 10.2 0.00
3.3 3.3 0.00
1.8 1.8 0.00
15.3 15.3 0.00
tIndicates that continuous data were not available
203
-------
TABLE D-ll. DAILY METEOROLOGICAL AND RUNOFF DATA FOR FEBRUARY, 1977
Air Temp
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Max
°C
8.7
6.9
11.0
14.0
12.0
13.0
5.0
15.0
18.5
18,0
9.1
14.0
20.3
12.2
1.9
9.9
18.8
19.3
11.5
16.4
23.9
23.5
13.8
18.0
11.2
6.2
9.2
14.9
Min
-6.2
4.0
-0.8
-1.1
-6.2
-3.8
-9.0
0.1
2.0
4.0
6.2
5.0
1.0
-1.0
-4.2
-5.1
0.2
0.0
0.2
-1.3
2.4
11.5
8.0
3.7
6.0
-1.9
-3.7
-2.2
Rel
Humid
V
10
75
82
72
61
56
62
73
67
68
72
100
70
60
70
73
82
61
55
59
52
52
69
62
38
55
93
79
61
Solar
Radiation
Cal/cm2
303
66
281
309
339
282
310
324
336
324
37
355 '
363
336
262
246
374
372
379
395
380
210
107
341
206
129
344
438
Mind
Travel
km
71
142
121
114
117
119
126
126
166
167
156
134
179
212
72
56
117
130
154
135
230
467
499
259
191
122
85
Pan Rainfall
Evap Gage 1 Gage 2 Runoff
mm mm mm mm
22.4 22.6 0.00
1.3 1.3 0.00
6.6 5.1 0.00
TOTAL 30.3 29.0 0.00
204
-------
TABLE D-12. DAILY METEOROLOGICAL AND RUNOFF DATA FOR MARCH, 1977
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air Temo
Max
°C
11.2
11.4
10.6
9.1
8.9
15.1
21.2
24.6
20.0
18.8
15.6
10.3
22.4
26.5
17.9
16.2
19.2
16.7
15.0
20.0
12.0
17.9
21.5
18.9
17.8
21.1
16.8
24.2
21.6
16.2
14.2
Min
°C
-1.8
8.3
2.0
-1.3
-3.2
-0.2
1.7
8.5
10.3
9.9
5.5
3.0
1.2
7.1
3.6
4.1
12.0
.5.9
6.0
-0.5
0.9
-1.0
4.0
10.0
10.6
13.9
12.0
9.2
4.2
5.1
0.2
Rel
Humid
%
61 '
77
54
65
68
54
45
35
58
83
60
70
50
56
62
48
71
59
52
54
66
50
45
63
88
92
98
65
60
47
64
Solar
Radiation
Cal /cm2
311
40
376
438
293
447
464
407
426
302
255
147
477
483
469
403
59
390
498
489
384
524
518
278
185
210
124
522
489
566
497
Wind
Travel
km
309
307
201
105
113
88
80
327
410
401
386
351
92
322
150
145
317
117
253
269
190
116
111
323
171
380
187
283
138
148
100
Pan Rainfall
Evap Gage 1 Gage 2 Runoff
mm mm mm mm
2.0 2.0 0.00
24.6 23.9 0.00
2.5 2.5 0.00
17.0 19.1 0.00
5.8 5.3 0.00
TOTAL 51.9 52.8 0.00
205
-------
TABLE D-13. DAILY METEOROLOGICAL AND RUNOFF DATA FOR APRIL, 1977
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
15.0
18.8
20.2
14.9
16.1
26.0
28.5
28.9
27.1
26.7
24.2
24.5
25.1
23.6
24.4
21.1
23.2
19.4
23.5
27.0
13.0
16.0
19.3
19.5
19.0
22.6
28.6
28.9
27.5
23.0
Temo
Min
°C
8.0
8.7
5.8
3.1
-0.7
5.2
11.1
10.9
12.8
14.8
14.1
15.0
15.0
12.9
13.9
15.0
15.6
13.9
10.3
13.0
10.1
8.8
10.0
8.2
5.0
5.0
12.2
18.0
18.0
16.9
Rel
Humid
I
89
60
73
70
58
50
45
48
52
47
58
62
79
63
76
94
89
94
82
92
98
94
87
68
63
59
58
69
78
93
Solar
Radiation
Cal/cm2
143
526
352
464
542
570
570
579
578
583
451
348
228
428
386
293
330
263
518
275
132
246
374
619
572
636
580
572
479
343
Mind
Travel
km
230
338
193
280
140
156
117
138
261
240
267
235
159
103
135
148
74
64
42
98
42
90
77
103
61
61
262
140
108
98
Pan
Evap
mm
8.9
13.2
9.7
8.4
3.6
4.3
5.1
10.7
10.2
6.4
0.8
5.8
4.8
4.8
5.8
10.2
6.1
9.1
4.8
Rainfa
Gage 1
mm
2.8
1.5
1.0
16.5
10.2
1.0
13.5
2.0
0.5
1.0
2.3
11
Gage 2
mm
2.5
1.8
1.0
20.8
6.4
1.0
12.7
1.5
1.0
1.5
2.0
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
TOTAL 52.3 52.2 0.00
206
-------
TABLE D-14. DAILY METEOROLOGICAL AND RUNOFF DATA FOR MAY, 1977
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
23.6
24.8
28.7
27.9
27.0
26.8
29.2
31.0
25.7
23.1
23.0
25.2
26.0
27.4
30.0
28.0
25.8
26.2
24.9
23.2
23.1
27.5
26.6
28.2
28.1
28.0
27.9
27.5
28.3
31.4
24.9
Temp
Min
°C
17.8
16.1
15.0
17.8
16.0
15.7
17.9
18.0
16.0
13.9
10.7
10.5
13.0
16.8
17'. 8
15.2
15.0
19.3
16.2
14.8
14.6
13.2
15.3
18.3
18.2
19.0
15.8
18.0
18.3
18.1
17.8
Rel
Humid
or
to
90
84
78
81
88
85
81
78
79
67
61
62
84
67
74
78
81
74
89
94
75
74
88
78
78
80
80
84
84
80
91
Solar
Radiation
Cal/cm2
278
419
572
445
305
511
577
574
526
575
575
651
361
633
622
398
497
548
250
204
524
666
467
601
598
423
452
524
406
534
298
Mind
Travel
km
95
63
156
282
154
100
71
122
103
93
134
71
203
294
203
261
301
163
179
201
124
262
135
119
124
122
122
175
76
26
219
Pan
Evap
mm
2.0
6.4
7.9
7.1
4.3
6.4
8.1
7.4
6.1
7.4
5.6
5.8
8.6
5.8
6.9
7.6
6.4
6.9
5.6
TOTAL
Rainfa
Gage 1
mm
1.8
2.8
26.7
1.8
19.3
7.6
22.1
81.5
17.0
37.6
21.8
2.8
8.4
251.2
11
Gage 2
mm
1.8
3,0
28.4
-
0.00
17.8
8.9
23.4
86.6
18.0
39.4
22.6
2.3
7.4
259.6
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
33.81
10.46
13.26
.05
1.85
0.00
0.00
59.43
207
-------
TABLE D-15. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JUNE, 1977
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
29.4
29.7
33.0
33.0
34.9
29.9
26.2
30.3
35.2
32.9
34.3
33.4
31.3
33.0
28.4
29.0
34.5
34.1
33.0
34.3
33.0
32.7
31.1
27.0
28.7
28.9
34.0
35.4
32.2
34.1
Tetno
Min
°C
16.5
19.6
18.8
22.0
21.6
19.0
14.1
15.4
23.0
24.2
22.4
21.4
19.8
20.6
21.1
21.0
22.0
23.5
25.0
21.7
23.7
21.0
21.8
20.3
24.1
21.9
22.1
21.2
20.8
21.1
Rel
Humi d
%
70
68
72
70
63
71
67
61
56
66
65
79
77
70
80
85
71
70
75
67
69
76
81
90
83
87
83
75
79
71
Solar
Radiation
Cal/on2
683
641
583
672
672
532
676
662
653
636
660
449
Wind
Travel
km
97
80
80
82
114
105
158
140
145
113
182
190
37
108
257
130
158
177
225
153
187
159
214
163
87
42
275
32
237
196
Pan
Evap
mm
6.6
7.1
7.9
5.1
7.4
8.4
7.6
7.9
7.4
7.9
7.9
7.9
7.4
7.4
7.9
7.9
9.4
7.9
8.6
11.2
7.4
6.9
5.1
0.8
5.3
7.1
7.1
7.9
Rainfa 1 1
Gage 1 Gage 2
mm mm
0.8 1.5
5.8 5.8
2.0 2.3
2.5 2.0
15.2 15.2
3.0 0.8
0.5 0.3
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
TOTAL 29.8 27.9 0.00
208
-------
TABLE D-16. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JULY, 1977
Date
I
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
"'Air
Max
°C
27.5
32.3
33.0
32.9
33.2
34.0
34.4
29.2
31.3
34.5
35.3
36.2
35.6
36.1
35.7
36.0
35.0
35.0
35.2
36.9
35.7
33.8
37.2
38.4
40.0
29.0
28.3
33.0
35.6
37.0
34.0
Temo Rel
Solar
Min Humid Radiation
8C % Cal/ctn2
18.0 88 373
22.7 75 615
23.6 66 675
21.8 64 679
23.4 68 656
22.9 66 669
23.1 66 652
21.1 83 478
22.3 84 502
21.1 71 655
25.9 57 646
25.6 57 619
23.8 53 670
23.5 54 653
24.0 70 501
24.4 64 634
23.2 65 614
23.4 58 644
23.8 60 577
23.0 66 643
17.6 83 436
21.7 84 486
22.1 70 631
25.0 58 580
Wind
Travel
km
140
245
161
200
195
129
174
106
114
171
262
187
158
158
122
188
114
156
176
142
87
77
114
402
26.1 57 627
21.0 90 245
18.8 87 351
20.8 75 581
21 .2 60 639
171
85
74
114
23.2 64 640
18.9 78 453
Pan Rainfal
Evap Gage 1
mm mm
45.7
14.0
10.9
11.4
11.4
10.4
7.9
1.3 8.4
8.6
12.4
14.2
10.7
11.4
15.0
8.1 5.3
14.7
6.4
14.0
10.4
8.4
12.7
11.7
8.4
10.7
5.6
7.1
3.8
8.4
0.5
27.9
1
Gage 2 Runoff
mm mm
45.7 2.49
8.9 0.05
3.3 0.03
12.4 0.08
0.5 0.00
25.4 0.10
TOTAL 100.5 96.2 2.75
209
-------
TABLE D-17. DAILY METEOROLOGICAL AND RUNOFF DATA FOR AUGUST, 1977
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air 1
Max
°C
32.0
33.9
32.9
34.0
34.9
35.0
36.2
35.9
36.7
37.0
26.6
30.2
25.9
34.1
33.0
37.0
25.2
26.0
22.9
27.9
31.2
32.0
34.2
33.0
34.9
35.3
33.4
26.8
27.0
31.0
32.1
Feme
Win
°C
19.3
18.9
21.2
23.8
24.0
24.0
24.8
25.1
25.1
24.8
20.0
18.7
20.0
21.1
21.2
23.6
20.0
16.7
20.0
20.2
20.2
19.2
20.9
22.1
22.1
24.9
25.2
16.1
18.1
21.1
22.8
Rel
Humid
01
n
60
65
69
62
64
71
62
58
59
65
90
83
97
85
77
74
96
75
94
86
81
74
82
83
71
63
68
98
93
78
75
Solar
Radiation
Cal/cm2
619
622
530
500
559
439
606
596
577
539
276
407
172
485
589
458
158
330
86
348
482
497
484
542
539
537
540
160
283
484
502
Wind
Travel
km
101
56
143
216
193
142
185
156
174
106
177
126
58
109
145
109
82
T34
95
35
43
m
79
134
254
336
402
79
53
106
117
Pan Rainfal
Evap Gage 1 (
mm mm
0.5
5.1 1.8
7.6
7.9
10.7
9.1
10.4
8.4
9.4
7.6
5.3
9.7
22.4
5.3
9.7
2.0 3.6
4.6 10.7
3.8
3.3
5.1
4.6
8.6
6.4
7.9
8..4
IS. 3
2.0
12.4
2.5
5.6
6.1
Sage 2 Runoff
mm mm
2.8 0.00
23.4 0.00
4.1 0.00
8.1 0.00
3.0 0.00
11.4 0.00
TOTAL
54.2
52.8
0.00
210
-------
TABLE D-18. DAILY METEOROLOGICAL AND RUNOFF DATA FOR SEPTEMBER, 1977
Air Terno
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Max
°C
31.9
33.1
33.9
31.3
26.2
29.2
29.1
31.0
26.7
26.1
25.9
32.5
22.1
17.7
25.1
30.2
31.1
31.9
25.1
28.6
33.3
32.2
28.4
28.2
31.8
34.8
30.0
24.4
28.5
35.0
Min
°C
22.5
21.0
21.3
20.6
20.2
20.0
19.8
20.1
17.0
17.1
18.8
21.2
16.9
14.5
14.2
18.2
21.8
19.6
14.8
13.3
21.7
20.0
21.1
17.0
18.0
17.0
21.2
20.0
19.6
21.1
Rel
Humid
c/
JO
74
70
66
88
93
86
84
79
79
76
93
75
93
100
83
78
76
69
74
71
67
75
82
62
72
75
87
99
92
63
Solar
Radiation
Ca1/cm2
500
542
486
181
257
394
472
472
345
360
242
448
185
96
436
377
388
499
504
364
465
452
154
479
468
446
344
113
358
360
Wind
Travel
km
84
77
34
88
77
76
79
121
150
179
167
204
217
161
121
225
156
150
72
201
212
187
88
105
106
135
137
166
182
137
Pan
Evap
nun
5.6
9.7
1.5
3.0
4.6
5.6
6.9
8.4
0.5
0.8
3.3
5.3
6.4
6.4
4.8
8.1
7.6
4.6
5.3
5.8
5.6
5.8
3.8
0.8
10.9
4.6
TOTAL
Rainfall
Gage 1
mm
10.9
4.1
14.7
7.4
5.3
4.6
3.8
3.0
3.8
57.6
Gage 2
mm
8.9
4.6
15.5
7.1
4.1
5.6
3.8
3.6
3.3
56.5
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
211
-------
TABLE D-19. DAILY METEOROLOGICAL AND RUNOFF DATA FOR OCTOBER, 1977
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
28.2
20.5
20.1
18.0
22.2
18.0
25.3
19.8
22.3
24.1
15.3
18.5
26.8
28.1
17.7
21.0
29.8
27.0
25.1
30.0
28.9
25.2
15.9
22.5
19.1
30.0
28.7
22.0
25.2
20.9
25.6
Temo
Min
ec
15.3
11.0
7.9
11.0
13.2
15.0
16.0
7.7
4.4
7.6
5.0
0.7
5.2
7.8
5.0
1.0
9.8
5.9
7.0
10.8
14.3
15.9
12.0
11.0
12.0
8.2
15.0
16.8
13.5
18.1
17,8
Rel
Humid
Of
JO
69
74
68
77
75
95
78
63
60
61
60
57
42
40
58
59
52
59
60
61
72
91
100
88
90
68
66
94
80
94
84
Solar
Radiation
Cal/cm2
301
422
434
160
221
70
199
255
368
306
421
415
407
412
349
400
385
385
377
362
333
198
63
294
246
355
281
132
279
56
305
Wind
Travel
km
90
117
100
174
124
159
237
68
154
185
209
43
69
143
80
130
92
16
27
198
200
84
72
37
109
60
117
24
214
111
34
Pan Rainfal
Evap Gage 1
mm mm
4.6
4.6
1.3
2.5
3.5
3.0 0.8
4.1 0.8
3.0
2.8
5.3
3.3
4.1
7.6
5.1
5.6
23.1
0.3
5.6
Gage 2 Runoff
mm mm
0.5 0.00
0.5 0.00
7.6 0.00
22.9 0.00
0.3 0.00
6.6 0.00
TOTAL 36.2 38.4 0.00
212
-------
TABLE D-20. DAILY METEOROLOGICAL AND RUNOFF DATA FOR NOVEMBER, 1977
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
18.7
11.0
18.3
20.8
15.8
16.3
18.1
14.0
7.8
12.6
17.7
19.5
20.8
22.0
20.2
20.9
15.0
18.1
22.1
22.0
6.8
12.6
12.0
10.2
11.1
13.9
11.1
5.0
10.7
8.8
Temp
Min
°C
7.0
7.2
10.8
12.5
14.0
13.5
11.2
4.0
0.0
-2.2
2.0
3.0
9.0
8.4
10.0
5.8
2.8
2.9
15.0
0.8
-2.0
-1.0
3.0
-1.0
-1.0
-3.1
4.0
2.5
-0.6
-2.0
Rel
Humid
%
99
100
96
81
100
98
98
100
67
60
71
61
70
82
89
74
61
56
88
66
59
76
91
87
64
56
62
77
79
89
Solar
Radiation
Cal/cm2
83
56
149
303
43
68
125
38
237
323
307
291
280
235
169
290
294
254
169
242
262
262
119
182
252
235
248
23
217
114
Wind
Travel
km
286
164
130
105
42
58
135
4
373
72
42
204
138
246
74
85
51
341
344
346
113
204
106
126
148
121
153
126
56
122
Pan Rainfall
Evap Gage 1 Gage 2 Runoff
mm mm mm mm
2.3 2.0 0.00
0.5 0.5 0.00
26.2 26.5 0.00
4.6 4.6 0.00
0.5 0.5 0.00
0.00
TOTAL 34.1 34.1 0.00
213
-------
TABLE D-21. DAILY METEOROLOGICAL AND RUNOFF DATA FOR DECEMBER, 1977
Date
1
2
3
4
c
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
12.2
14.0
20.1
8.8
7.0
-1.0
8.0
10.5
-4.8
3.5
7.1
15.0
14.0
17.0
20.8
22.0
13.0
17.3
7.0
5.0
3.9
14.0
18.8
17.5
3.7
9.0
1.0
11.0
5.2
5.1
5.5
Temo
Min
c
-1.6
2.0
2.1
5.0
-7.0
-9.7
-6.0
-9.0
-12.0
-10.3
-2.0
6.8
2.9
-0.8
6.6
7.8
2.8
-1.0
2.0
-5.4
-5.0
-4.0
2.0
-3.0
-6.4
-5.5
-8.0
-3.9
2.2
3.7
-6.5
Rel
Humid
o/
a
67
64
63
96
86
54
64
77
52
53
50
95
70
59
47
64
51
52
75
69
57
34
39
57
66
62
75
64
100
100
97
Solar
Radiation
Cal/cm2
259
180
208
53
92
260
233
97
263
159
43
21
228
205
238
206
224
217
230
235
254
254
233
241
248
237
200
232
32
34
33
Wind
Travel
km
85
111
80
105
275
172
274
338
92
201
294
246
140
171
293
352
109
150
204
230
256
185
166
140
151
243
183
237
Pan Rainfall
Evap Gage 1 Gage 2 Runoff
mm iron mm ititn
2.0 2.8 0.00
2.8 2.5 0.00
2.0 2.0 0.00
TOTAL 6.8 7.3 0.00
214
-------
TABLE D-22. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JANUARY, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
"Air"
Max
°C
-5.9
6.0
8.2
12.6
9.4
14.7
8.3
-0.5
-5.9
-5.8
-4.2
-1.7
4.0
0.8
1.5
4.4
-2.8
-8.9
-7.0
-8.2
-5.0
1.0
0.9
0.4
0.0
-2.1
-3.5
2.0
-1.3
0.0
-2.8
Temo
Min
c
-9.4
-11.8
-6.0
-1.0
-0.9
-4.9
-0.5
-9.3
-11.4
-11.0
-6.3
-6.2
-10.0
-10.0
-4.9
-2.8
-17.8
-16.7
-11.6
-10.4
-9.5
-7.8
-4.4
-1.2
-8.4
-10.9
-9.1
-10.0
-10.3
-4.0
-6.2
Re)
Humid
Of
SO
72
60
74
79
86
77
89
54
47
53
80
96
82
73
82
94
93
89
98
100
100
82
70
76
82
73
88
95
Solar
Radiation
Cal/cm2
143.4
303.8
248.4
261.1
250.7
271.7
158.8
297.9
187.7
215.2
53.6
140.8
286.2
297.7
163.6
90.0
254.3
137.0
148.3
278.3
164.4
195.2
96.7
61.9
301.0
344.2
224.1
302.3
307.4
103.9
95.3
Wind
Travel
km
142
84
183
203
51
85
375
277
127
156
98
37
208
24
230
66
31
164
222
74
134
200
180
217
278
98
45
92
150
m
121
Pan Rainfa
Evap Gage 1
inn mm
1.0
1.5
5.3
12.7
0.3
0.5
1.0
1.8
2.0
n
Gage 2
mm
1.0
1.8
3.6
12.4
0.5
0.3
0.5
1.5
1.5
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
TOTAL 26.1 23.1 0.00
215
-------
TABLE D-23. DAILY METEOROLOGICAL AND RUNOFF DATA FOR FEBRUARY, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
25
27
28
'" Air
Max
°C
1.1
-5.0
3.8
1.9
0.0
1.7
-2.8
-3.6
-3.1
0.2
1.0
2.3
5.0
-2.4
-1.1
-2.1
-5.8
-7.2
1.8
3.3
-2.0
8.7
9.9
17.1
2.8
7.9
6.7
3.1
Temo
Win
°C
-6.6
-11.3
-5.9
-1.9
-5.4
-8.4
-7.1
-6.8
-6.7
-4.3
-2.1
0.1
-5.6
-8.9
-5.8
-8.6
-7.8
-21.1
-17.8
-7.2
-11.8
-6.5
-0.7
2.2
-1.0
-4.2
1.2
0.4
Rel
Humid
01
11
99
85
90
99
77
68
100
88
94
92
100
100
93
92
93
98
95
85
88
91
75
73
67
67
75
64
80
99
Solar
Radiation
Ca1/cm2
97.3
197.7
189.2
148.9
335.8
195.0
106.6
149.6
201.9
222.8
88.4
37.3
201.1
352.1
249.2
168.6
211.1
447.3
455.0
313.7
468.6
448.7
451.5
404.7
57.2
76.6
Wind Pan Rainfal
Travel Evap Gage 1
km im nun
206 1.5
92
111
129
171
251
216 3.3
222 1.3
109 1.5
148
106 1.3
290 48.0
201 2.8
130
72 1.3
191 1.5
142 0.5
64
51
381
84
187
105
171
135
259 1 .8
219
212
Gage 2 Runoff
mm mm
1.5 0.00
2.3 0.00
1.0 0.00
1.8 0.00
1.0 0.00
47.2 3.40
2.3 0.00
1.5 0.00
1.3 0.00
0.5 0.00
1.5 0.00
TOTAL 64.6 61.9 3.40
216
-------
TABLE D-24. DAILY METEOROLOGICAL AND RUNOFF DATA FOR MARCH, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air '
Max
°C
2.3
4.0
-3.1
0.0
12.6
19.8
3.9
5.0
12.0
19.2
13.1
15.9
20.0
11.7
8.9
11.2
18.5
27.9
23.1
21.9
22.0
26.8
18.0
4.5
10.0
14.2
23.5
27.0
26.4
25.9
27.9
Temp
Min
°C
-0.2
-5.7
-9.5
-11.7
-4.9
3.9
-0.3
-2.1
-5.6
1.0
0.9
-1.7
5.8
1.4
1.6
8.2
-0.3
4.7
12.8
9.1
4.0
11.3
4.5
1.0
0.1
-1.2
2.4
9.0
12.1
8.8
14.0
Rel
Humid
%
100
93
69
61
50
72
100
88
58
52
90
69
77
78
93
65
54
38
56
80
59
57
100
99
79
62
53
50
59
60
55
Solar
Radiation
Ca1/cm2
62.6
57.0
276.1
502.3
445.6
248.7
42.4
302.5
527.9
447.6
139.2
527.4
356.3
420.5
193.9
516.2
506.9
531.4
516.4
264.8
554.1
486.9
54.2
115.8
496.8
584.7
582.4
572.9
515.7
579.2
485.8
Wind Pan Rainfall
Travel Evap Gage 1 Gage 2
km mm mm mm
201 0.8 0.8
414 1.0 1.0
249
190
193
217
354 2.5 2.5
164
43
357
243
214
74
304
121 3.0 5,6
153
113
130
404
230
84
368 2.5 2.3
319 14.7 15.5
288 11.2 10.2
103
134
56
124
106
163
265
TOTAL 35.7 37.9
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.18
0.18
217
-------
TABLE D-25. DAILY METEOROLOGICAL AND RUNOFF DATA FOR APRIL, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
28.8
29.4
28.8
24.4
26.1
22.2
27.2
27.8
28.3
25.0
14.4
19.4
25.0
23.9
27.8
27.8
22.2
27.8
22.2
16.7
15.0
20.0
25.6
25.6
24.4
19.4
22.8
26.7
26.7
26.1
Temp
Ntin
°C
12.8
16.7
16.1
11.1
15.6
11.7
14.4
17.8
18.3
10.6
1.7
5.0
5.6
11.7
14.4
15.6
16.7
7.2
7.2
0.0
2.2
7.8
2.2
7.8
3.3
4.4
3.9
11.1
15.0
17.2
Rel
Humid
%
89.8
58.6
76.4
75.1
91.8
94.8
81.4
50.8
69.8
73.2
62.2
55.2
44.6
49.3
73.2
62.3
51.7
76.5
88.1
99.2
Solar
Radiation
Cal/cm2
476
318
254
492
199
530
586
464
243
218
655
646
623
269
Mind
Travel
km
311
299
121
230
275
135
265
261
381
71
143
114
222
209
249
206
275
385
224
126
298
122
108
179
124
171
175
307
145
Pan Rainfall
Evap Gage 1 Gage 2
mm mm mm
2.8 4.3
0.5 0.0
4.6 3.8
8.4 9.4
5.6 5.6
1.8 1.8
13.0 13.0
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
TOTAL 36.7 37.9 0.00
218
-------
TABLE D-26. DAILY METEOROLOGICAL AND RUNOFF DATA FOR MAY, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
22.2
19.4
13.3
8.9
15.0
16.7
21.7
23.0
22.0
24.5
30.5
24.0
23.0
31.3
26.5
24.0
22.0
26.0
31.0
25.0
22.0
29.0
30.3
29.5
30.0
28.1
22.0
25.6
27.0
30.5
30.5
Temo
Min
°C
11.1
7.2
6.7
5.5
7.2
10.5
8.9
10..0
9.5
12.0
17.0
18.0
11.7
10.8
15.8
11.0
14.8
16.0
18.8
17.9
16.8
19.0
20.5
20.0
20.2
17.7
16.0
16.0
16.0
17.5
21.0
Rel
Humi d
of
n
59
70
73
66
57
62
62
76
88
97
78
92
99
84
82
78
81
83
99
95
80
78
77
Solar
Radiation
Cal/cm2
495
639
664
702
703
688
671
454
289
456
677
620
605
444
672
Mind
Travel
km
175
228
195
129
116
196
148
116
119
154
146
212
265
151
103
166
230
262
277
105
80
150
154
211
172
190
130
72
137
92
208
Pan Rainfall
Evap Gage 1 Gage 2 Runoff
mm mm mm mm
3.8 0.8
0.0 0.00
5.8 18.0 19.1 0.00
5.6 5.1
0.0
2.3
0.0
0.5 4.3
5.3
7.4
8.1
7.1
5.8
11.9
7.1
5.8
5.3
6.4
6.9 3.6
3.8 4.8
5.8 0.00
4.3 0.00
4.3 0.00
5.3 0.00
7.4 14.7 11.4 0.00
1.3 11.7
5.3
7.9
7.1
10.4
6.4 4.8
8.4 0.00
5.3 0.00
8.4 49.3 49.0 0.91
2.5 4.6
4.6
11.2
9.9
4.3 1.57
TOTAL
121.7 117.2
2.48
219
-------
TABLE D-27. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JUNE, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
26.1
21.0
24.2
27.5
24.0
25.0
30.0
24.0
28.0
28.9
32.0
29.0
27.5
30.0
32.5
32.5
33.0
25.0
31.0
29.0
22.0
30.3
32.1
33.1
33.0
33.0
32.0
33.3
34.0
34.0
Temo
Min
°C
18.0
16.8
14.1
16.0
17.0
17.0
17.8
14.0
14.0
17.0
22.0
21.0
17.0
18.8
21.5
23.0
24.2
17.0
18.0
18.5
18.0
17.5
23.0
24.2
25.8
24.0
24.0
23.2
22.5
24.0
Rel
Humid
a
a
92
95
90
89
93
86
75
69
68
71
71
61
71
76
74
74
76
99
79
92
100
88
74
76
68
67
74
76
72
70
Solar
Radiation
Cal/cm2
357
229
552
460
372
401
683
634
640
724
675
716
649
693
689
698
698
162
670
495
68
535
714
609
686
713
526
625
Wind
Travel
km
166
129
138
- 114
121
66
64
76
92
158
227
201
63
323
233
201
2.37
129
196
127
130
158
127
98
Pan
Evap
nun
8.6
3.8
4.6
7.9
2.5
3.6
7.6
3.6
5.3
8.6
8.6
8.4
6.9
7.1
8.6
8.1
8.1
0.8
6.1
9.7
3.8
6.1
5.1
13.7
8.9
7.6
8.1
9.9
11.7
11.7
TOTAL
Rainfa
Gage 1
nun
0.5
40.1
7.1
3.0
21.3
0.8
29.2
1.0
103.0
11
Gage 2
nun
0.8
45.7
7.9
4.3
18.0
0.8
29.2
1.0
107.7
Runoff
mm
0.00
5.82
0.13
0.00
0.08
0.00
0.20
0.00
6.23
220
-------
TABLE D-28. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JULY, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
36.0
36.0
37.0
36.0
36.2
36.0
36.7
38.0
40.0
38.0
38.0
36.5
38.8
38.0
34.5
34.6
35.1
37.0
37.2
38.8
37.2
36.7
33.9
31.8
35.2
38.0
32.7
35.0
38.0
34.0
35.0
Temo
Min
°C
23.8
22.0
23.3
23.5
25.0
25.4
23.0
23.8
26.6
23.8
23.2
25.2
26.0
20.0
22.0
22.0
23.0
26.0
25.3
24.0
23.9
22.8
20.0
17.2
22.0
24.0
18.8
18.8
24.7
29.0
19.2
Re1
Humid
%
66
67
67
67
63
68
73
64
47
61
63
62
64
69
75
68
63
53
57
58
66
69
58
57
53
61
68
Solar
Radiation
Ca1/oti2
668
701
716
650
446
672
705
683
641
651
Wind
Travel
km
156
182
37
84
132
175
196
90
187
117
58
182
203
183
156
90
97
198
264
164
161
114
249
69
60
142
100
109
116
150
182
Pan
Evap
mm
13.0
12.2
7.4
7.6
10.2
13.0
10.9
8.4
11.4
11.9
10.4
10.4
9.9
15.0
11.4
9.1
9.4
11.2
10.4
11.7
5.1
17.0
4.8
7.6
6.4
8.1
9.4
10.2
0.0
10.2
0.0
TOTAL
Rainfall
Gage 1 Gage 2
mm mm
1.0 1.3
5.6 3.8
0.8 0.0
1.3 0.0
1.3 3.8
6.4 0.0
20.1 29.0
36.5 37.9
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
221
-------
TABLE D-29. DAILY METEOROLOGICAL AND RUNOFF DATA FOR AUGUST, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
T6
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
AiV
Max
°C
32.0
32.0
27.8
20.0
27.5
31.0
31.2
32.0.
32.0
31.2
36.5
37.2
38.0
36.2
34.6
37.0
37.8
38.9
38.9
32.8
35.0
34.2
36.0
36.0
37.0
36.2
37.0
27.0
28.8
27.5
31.2
Temp
Min
°C
21.0
22.2
19.8
17.0
17.0
17.0
20.5
19.5
20.5
20.5
21.8
24.0
25.0
24.0
26.0
21.0
20.0
27.8
16.7
13.9
15.6
23.0
22.5
24.0
23.8
25.2
25.0
19.8
19.5
15.0
14.5
Rel
Humid
V
JO
69
82
96
100
85
70
63
51
60
69
60
56
58
62
64
47
62
57
56
57
62
66
83
68
61
60
Solar
Radiation
Cal/cm2
632
391
298
117
466
661
571
603
497
409
638
647
631
617
493
630
621
601
192
606
579
573
Mind
Travel
km
212
245
124
175
126
53
56
80
93
40
48
190
191
145
291
85
175
367
285
92
35
135
138
195
161
191
253
265
146
209
114
Pan Rainfall
Evap Gage 1 Gage 2
mm nun mm
11.4
4.8 5.1 5.1
3.8 25.4 21.6
3.0 1.3 1.3
2.0
6.6
7.9
8.9
5.6
5.6 11.9 13.2
2.5
16.0
19.8
13.7
11.2
13.2
15.2
18.8
6.1 15.0 16.5
3.8
10.9
9.1
11.2
11.4
10.9
10.9
10.7
8.9
6.6
8.1
9.4
TOTAL 58.7 57.7
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
222
-------
TABLE D-30. DAILY METEOROLOGICAL AND RUNOFF DATA FOR SEPTEMBER, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
c
31.1
34.2
36.8
38.1
29.0
35.8
34.1
31.4
28.3
32.9
30.0
36.2
33.7
31.2
35.8
37.0
33.5
33.4
33.2
26.2
21.5
22.8
28.4
29.3
24.0
26.3
29.7
30.8
31.0
25.4
Temo
Min
ec
20.0
20.9
22.9
22.0
21.9
20.0
22.0
20.6
21.8
20.7
22.6
23.4
23.5
18.0
22.6
23.3
25.2-
25.3
24.0
13.5
11.6
11.5
12.7
17.8
19.9
17.6
15.0
14.1
16.9
14.7
Rel Solar
Humid Radiation
% Cal /cm2
70
69
59
48
62
56
58
67
84
78
85
80
78
85
72
58
67
66
68
89
73
65
75
80
84
69
74
67
62
62
Wind
Travel
km
129
45
142
142
74
48
84
84
84
129
187
293
180
272
200
206
175
439
333
233
227
217
72
14
58
45
92
56
45
206
Pan Rainfal
Evap Gage 1
mm mm
5.8
10.9
8.9
9.1
7.1 0.8
3.0
8.4
10.2
6.9
4.8
5.3
6.6
7.1 15.0
7.1
7.1
9.4
6.4
17.3
12.7
7.6 11.7
6.6 4.3
5.8
4.6
3.8
1.5
2.5
2.5
4.8
4.1
10.4
TOTAL 31 .8
Gage 2 Runoff
mm mm
0.8 0.00
16.5 0.00
11.2 0.00-
4.3 0.00
32.8 0.00
223
-------
TABLE D-31. DAILY METEOROLOGICAL AND RUNOFF DATA FOR OCTOBER, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
29.8
33.0
24.9
28.2
23.0
20.8
26.2
17.1
24.4
27.8
29.8
32.0
18.0
21.0
26.4
23.0
22.4
27.1
24.0
29.9
30.1
25.6
12.8
20.3
21.9
17.4
23.6
24.1
23.0
26.0
25.8
Temo
Min
C
11.9
18.6
14.4
9.8
10.0
5.1
7.7
12.4
12.1
15.6
14.4
16.5
7.1
3.9
3.8
6.9
6.7
10.0
8.8
9.2
14.0
8.8
7.0
3.7
7.4
3.6
4.7
6.2
6.5
7.6
8.9
Rel
Humid
%
60
51
50
49
48
61
57
79
81
70
76
66
54
56
53
57
58
54
63
59
40
82
66
78
74
67
55
52
55
59
68
Solar
Radiation
Cal/cm2
471
459
40
370
439
433
431
446
446
437
436
423
415
410
401
392
252
234
296
372
403
399
389
377
367
371
Wind
Travel
km
219
208
422
119
309
233
116
180
243
154
166
140
436
224
148
138
154
270
183
51
134
447
414
148
254
180
270
93
182
126
138
Pan Rainfall
Evap Gage 1 Gage 2
mm mm mm
7.1
6.1
9.1
9.1
7.1
6.9
7.1
4.8 51.8 52.8
3.8
3.8
10.9
2.0
11.2
7.9
4.6
5.3
7.9
4.8
6.1
5.6
5.6
8.6 2.5 2.8
5.8 3.6 3.6
2.8
3.3
1.3
2.0
6.4
4.8
4.3
3.6
Runoff
mm
0.00
0.00
0.00
TOTAL
57.9
59.2
0.00
224
-------
TABLE D-32. DAILY METEOROLOGICAL AND RUNOFF DATA FOR NOVEMBER, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
91
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
21.7
26.8
27.8
26.7
24.9
7.5
14.4
19.7
20.8
23.7
10.4
15.0
17.6
11.0
2.8
3.6
6.5
17.9
11.3
5.0
3.0
11.4
16.0
15.5
17.5
17.8
6.8
11.5
13.0
12.3
Temo
Min
°C
5.9
8.7
14.9
' 13.6
12.8
5.1
-0.3
3.8
7.3
10.1
4.1
3.8
11.0
1,0
1.0
2.2
0.0
0.1
1.7
0.0
-1.0
2.0
8.6
3.0
9.0
1.5
- 0.0
-1.5
4.0
3.8
Rel
Humi d
V
rt
76
63
55
68
76
96
70
57
60
73
91
100
88
78
100
100
99
85
92
94
97
100
83
78
100
100
84
76
78
83
Solar
Radiation
Ca1/cm2
334
365
321
282
238
69
358
372
340
319
194
64
98
49
38
48
119
303
247
115
105
42
232
218
28
53
285
301
292
125
Wind
Travel
km
97
63
134
163
201
259
220
37
248
204
212
357
327
219
420
274
249
84
224
134
338
151
122
219
187
161
434
31
64
108
Pan Rainfa
Evap Gage 1
mm (tun
3.0
18.5
2.5
0.8
47.0
4.8
5.3
3.0
2.3
2.8
11
Gage 2
tun
4.1
16.5
2.8
1.8
48.3
6.9
4.6
3.6
3.6
2.0
Runoff
mm
0.00
0.00
0.00
0.00
1.52
0.00
0.00
0.00
0.00
0.00
TOTAL 90.0 94.7 1.52
225
-------
TABLE D-33. DAILY METEOROLOGICAL AND RUNOFF DATA FOR DECEMBER, 1978
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
14.1
16.9
-1.5
9.8
16.1
0.8
-4.0
-3.8
1.8
9.3
9.2
15.4
6.0
9.5
11.5
9.0
9.0
16.9
19.8
19.1
11.9
10.8
11.6
4.8
14.0
8.0
8.0
12.0
9.5
-7.0
-8.0
Temo
Min
°C
5.0
-2.0
-6.9
-6.8
0.0
-4.0
-8.0
-9.8
-12.0
-6.0
-4.5
-0.5
-3.2
-6.2
-1.0
-3.2
-7.2
5.6
14.0
1.7
-5.0
-2.1
1.0
-7.3
-0.5
-5.0
-6.4
2.6
-7.0
-8.6
-11.0
Rel
Humid
o/
a
90
98
77
62
59
81
92
78
61
45
62
50
75
67
80
62
52
55
73
74
60
60
71
74
64
72
69
73
99
100
98
Solar
Radiation
Cal/cm2
223
113
207
302
286
117
97
270
311
270
297
282
215
310
296
254
204
148
108
217
290
286
254
292
293
290
194
172
39
43
93
Wind Pan Rainfall
Travel Evap Gage 1 Gage 2
km mm mm mm
388
253
470
159
261
430
455
502
177
87
64
76
161
93
56
103
150
175
243
190
198
96
79
154
211
188
209
257
169
299 1.0 1.3
357 10.4 9.6
TOTAL . 11.4 10.9
Runoff
mm
0.00
0.00
0.00
226
-------
TABLE D-34. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JANUARY, 1979
Air Temp
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Max
°C
-8.3
-12.2
-3.3
-2.0
-8.9
-6.3
-6.1
-1.2
-0.6
-1.9
-1.1
3.6
0.0
-8.9
1.7
5.7
5.7
10.2
10.2
4.1
4.6
9.7
4.2
-2.2
1.9
0.1
-6.2
-4.9
-3.1
-6.4
-4.8
Min
°C
-14.4
-16.7
-15.0
-7.2
-10.8
-10.6
-19.4
-19.4
-7.3
-7.3
-7.8
-2.2
-14.0
-16.5
-12.3
-3.0
-2.8
-0.9
-1.0
-1.9
-1.0
0.0
-9.8
-13.3
-4.6
-6.2
-11.1
-12.2
-17.8
-11.7
-21.1
Rel
Humi d
ot
.0
97
97
98
96
69
65
96
100
91
92
72
71
94
87
100
100
85
67
59
98
84
86
100
90
86
95
92
78
Solar
Radiation
Ca1/cm2
295
309
275
96
107
101
251
331
301
125
93
219
170
312
194
215
281
22
133
227
309
159
160
348
83
134
341
365
123
307
391
Wind
Travel
km
333
270
77
43
217
183
200
77
121
241
182
264
468
132
170
138
122
143
88
344
254
90
547
121
198
351
169
92
158
172
40
Pan Rainfall
Evap Gage 1
mm mm
0.5
2.8
3.5
21.1
3.5
3.0
2.5
0.8
1.8
0.0
Gage 2
iron
0.0
2.5
3.8
20.3
1.3
2.5
1.3
0.0
2.5
0.8
Runoff
mm
0.00
0.00
0.00
8.35
0.00
0.00
0.00
0.00
0.00
0.00
TOTAL 3975 35TO
227
-------
TABLE D-35. DAILY METEOROLOGICAL AND RUNOFF DATA FOR FEBRUARY, 1979
Date
1
2
3
4
5
6
7
8
9
10
n
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Air
Max
°C
1.1
3.9
-4.0
-2.7
-4.2
-0.3
-2.1
-0.2
-3.0
7.4
10.2
3.7
1.9
10.2
1.4
-9.2
-8.1
3.8
10.1
5.7
9.8
18.6
12.1
1.9
2.0
11.7
14.9
5.9
Temo
Win
°C
-22.7
-7.5
-10.3
-12.1
-17.2
-4.2
-13.0
-12.2
-21.7
-8.2
-2.1
-2.6
-6.2
0.0
-9.5
-14.0
-11.9
-9.1
-3.1
.9
-2.3
7.0
-1.8
-2.2
-3.3
-3.7
1.8
3.4
Rel
Humi d
Of
IQ
73
96
87
82
76
97
79
90
73
78
92
97
100
100
89
70
94
75
73
100
90
78
76
90
75
65
62
100
Solar
Radiation
Ca1/on2
234
288
331
107
411
269
418
414
318
135
128
258
in
219
83
443
425
90
251
258
439
126
453
425
352
85
Wind
Travel
km
56
335
179
200
216
93
230
177
277
105
76
150
98
61
100
235
174
251
261
272
127
138
227
306
257
262
177
317
Pan Rainfall
Evap Gage 1 Gage 2 Runoff
mm nun mm mm
3.0 2.5 0.00
1.3 3.8 0.00
0.8 1.3 0.00
0.5 0.0 0.00
2.5 1.5 0.00
TOTAL 8~7i972 OO
228
-------
TABLE D-36. DAILY METEOROLOGICAL AND RUNOFF DATA FOR MARCH, 1979
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
14.9
15.3
9.8
6.7
14.0
17.2
13.3
15.2
16.7
12.2
12.2
22.2
17.6
14.5
11.9
9.8
15.2
23.2
9.5
17.0
19.5
19.8
9.8
9.2
17.4
17.3
15.1
22.1
27.6
19.5
17.0
Temo
Min
°C
2.9
7.0
-1.0
-2.7
2.0
0.1
1.6
-1.1
1.7
-1.1
-1.1
3.9
6.7
0.0
2.0-
5.5
6.2
10.4
7.8.
6.9
8.6
6.0
2.2
0.1
-1.0
3.2
0.4
15.0
17.4
6.2
5.1
Rel
Humid
o/
to
77
89
90
66
65
76
75
69
60
61
74
95
100
79
93
81
93
80
84
66
65
68
77
90
81
74
81
Solar
Radiation
Cal/cm2
380
114
486
443
438
481
371
352
493
519
488
509
495
263
106
118
445
231
450
252
573
565
557
495
305
425
535
507
Wind Pan
Travel Evap
km mm
116
230
232
354
195
58
156
209
344
206
' 117
145
309
248
119
250
254
399
248
124
130
288
624
378
208
192
232
225
317
428
209
TOTAL
Rainfall
Gage 1 Gage 2 Runoff
mm mm mm
13.2 13.2 0.00
2.3 2.3 0.00
1.5 1.3 0.00
20.3 19.3 0.71
0.8 1.3 0.00
54.6 55.9 18.47
1.3 1.3 0.00
-
94.0 94.6 19.18
229
-------
TABLE D-37. DAILY METEOROLOGICAL AND RUNOFF DATA FOR APRIL, 1979
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
9.3
10.0
3.9
11.8
22.0
19.5
25.4
19.6
16.1-
16.3
19.2
17.6
19.6
25.7
28.3
28.1
25.5
16.3
22.0
19.0
20.9
21.9
21.8
26.0
25.8
20.3
14.0
14.4
19.6
22.5
Temp
Min
°C
4.6
1.2
1.0
1.0
3.5
1.6
14.3
7.2
3.0
6.7
12.0
7.0
7.4
8.9
1415
15.2
16.6
13.4
16.2
13.5
10.0
10.9
12.9
9.4
9.8
7.0
7.0
4.0
4.6
8.4
Rel
Hunri d
%
99
74
96
80
68
64
69
75
67
96
54
61
55
61
54
62
62
98
96
99
72
82
87
77
80
65
78
84
73
62
Solar
Radiation
Cal/cm2
148
514
198
571
620
599
544
585
605
154
457
106
339
593
437
443
596
577
672
309
265
653
578
Wind Pan
Travel Evap
km mm
332
235
in
185
84
90
188
236
283
135
332
330
in
122
132
114
183
228
254
219
122
61
145
5
245
251
108
85
88
64
TOTAL
Rainfa
Gage 1
mm
3.0
11.4
0.5
27.4
4.6
1.8
2.5
2.3
53,5
11
Gage 2
mm
3.0
10.2
0.5
25.4
3.5
2.0
2.5
2.5
49.6
Runoff
mm
0.00
0.00
0.00
2.18
0.00
0.00
0.00
0.00
2.18
230
-------
TABLE D-38. DAILY METEOROLOGICAL AND RUNOFF DATA FOR MAY, 1979
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
18.5
19.5
13.0
15.9
21
26.7
27.6
26.8
26.5
23.8
13.0
22.5
25.0
28.5
28.9
28.0
27.1
26.4
28.9
30.6
28.3
21.6
22.2
21.1
22.6
23.1
28.8
25.2
26.9
25.6
22.4
Terno
Min
°C
11.9
11.0
7.5
6.3
5.3
12.4
17.8
19.0
19.6
9.5
6.0
5.0
9.4
14.1
13.9
16.1
15.6
16.8
17.9
15.3
17.8
13.5
12.8
8.3
8.7
14.6
17.4
18.0
15.7
16.1
13.3
Rel
Humi d
w
n
92
100
100
83
73
70
78
85
85
95
82
70
64
56
60
64
74
83
86
96
74
69
62
85
82
95
84
92
77
Solar
Radiation
Cal/cm2
325
252
34
471
700
700
717
631
476
185
270
702
701
705
613
671
548
496
652
534
116
348
611
632
717
442
705
343
670 '
394
637
Wind
Travel
km
121
261
196
380
130
299
375
523
354
208
159
72
80
53
72
156
193
278
204
188
140
192
68
116
48
51
71
140
145
119
127
Pan
Evap
mm
6.1
8.1
9.9
6.3
7.6
2.3
5.1
7.1
3.8
5.3
11.2
8.6
4.3
9.6
6.1
8.1
2.0
1.0
7.9
5.8
7.9
4.1
6.6
3.8
5.8
4.8
Rainfa
Gage 1
mm
53.8
27.9
18.0
0.0
0.0
0.0
4.3
1.3
16.5
0.2
1.3
0.8
n
Gage 2
mm
54.1
27.7
T7.0
0.0
0.0
0.0
4.3 .
0.8
18.3
0.0
0.8
0.5
Runoff
mm
14.24
10.13
8.36
0.41
0.11
0.03
0.00
0.00
0.00
0.00
0.00
0.00
TOTAL 12771 ITS .'5"
33.28
231
-------
TABLE D-39. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JUNE, 1979
Date
1
2
3
4
5
5
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
23.5
22.6
26.8
30.5
25.9
28.6
32.2
29.9
27.5
24.2
27.2
27.9
30.4
31.9
31.0
31.0
29.5
29.9
29.0
32.6
31.9
30.3
28.7
24.9
25.4
28.6
30.0
33.0
32.9
28.5
Temo
Min
°C
13.9
14.5
12.5
16.6
18.1
18.1
18.6
19.7
15.0
12.0
13.2
15.9
16.8
20.6
20.8
20.7
22.2
21.9
23.1
20.9
20.7
19.1
20.9
19.0
17.6
18.2
21.0
22.1
22.0
20.6
Re1
Humi d
(W
10
78
91
75
70
98
93
85
97
98
71
67
67
70
64
71
70
76
50
87
80
89
89
96
95
96
86
82
86
77
85
Solar
Radiation
Cal/cm2
554
458
707
671
239
412
646
285
263
746
751
723
712
734
717
619
461
702
399
723
433
422
354
300
334
633
693
509
705
456
Wind
Travel
km
108
175
82
98
117
116
142
278
183
228
55
43
195
254
463
267
354
241
138
272
164
193
156
87
74
119
95
167
166
95
Pan
Evap
iren
5.6
3.0
6.6
10.7
1.8
0.8
1.3
1.3
6.9
9.6
10.2
14.0
6.3
7.1
10.4
8.1
6.3
7.6
8.1
2.5
3.8
3.6
3.6
3.6
6.3
4.3
10.7
TOTAL
KainTaii
Gage 1 Gage 2
nun mm
6.4 7.1
74.4 77.5
0.5 0.8
25.1 25.6
17.0 16.8
3.8 2.5
2.8 1.5
130.0 131.8
Runoff
nun
0.00
9.78
0.00
0.00
0.53
0.05
0.00
10.36
232
-------
TABLE D-40. DAILY METEOROLOGICAL AND RUNOFF DATA FOR JULY, 1979
" ... - . - -. - . _ .- -- . . -. . . ...
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max.
°C
34.4
33.0
33.0
34.8
33.4
25.6
27.6
32.3
33.6
33.5
31.3
32.0
32.8
33.5
31.0
32.4
25.2
23.8
27.7
29.6
30.2
30.6
27.3
31.5
32.0
31.4
31.0
33.9
35.1
34.9
25.1
Temp
Min.
°C
21.0
23.5
22.9
23.2
19.7
18.9
20.3
21.4
22.9
21.3
21.9
22.0
23.4
23.0
23.4
23.1
20.0
20.6
18.7
18.0
19.0
21.2
21.6
23.0
21.9
22.0
20.9
22.0
25.7
22.1
20.7
Rel
Humid
V
n
65
67
74
71
82
97
95
84
77
72
78
78
76
79
91
88
100
98
76
77
75
80
94
85
83
88
83
75
75
78
97
Solar
Radiation
Cal/cm2
590
683
724
709
623
364
346
699
553
628
673
636
694
678
514
562
265
204
543
630
586
521
225
602
628
507
515
670
556
590
239
Wind
Travel
km
163
240
241
209
206
127
92
68
95
43
69
80
76
143
90
80
88
134
56
58
50
109
93
93
103
85
109
174
175
158
174
TOTAL
Pan
Evap.
mm
5.6
8.6
11.4
10.2
15.0
23.1
3.8
2.5
8.1
6.4
6.4
8.6
6.1
9.1
6.1
6.6
10.2
2.3
2.5
3.6
8.1
4.1
5.8
4.1
3.3
9.1
6.1
6.6
7.6
10.7
5.6
Rainfall
Gage 1 Gage 2 Runoff
mm mm nun
42.9 44.2 1.24
8.9 8.4 2.03
0.03
*
76.2 87.6 23.60
0.08
0.03
3.3 4.1 0.00
2.3 3.3 0.00
8.1 6.1 0.00
141.7 153.7 27.01
233
-------
TABLE D-41. DAILY METEOROLOGICAL AND RUNOFF DATA FOR AUGUST, 1979
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
°C
29.9
32.0
32.4
34.5
35.0
34.9
34.1
33.6
32.7
34.6
26.1
26.8
32.0
34.4
27.2
32.6
32.8
33.9
35.0
29.4
32.0
30.8
29.5
31.0
28.0
27.7
29.5
33.4
33.2
33.3
25.8
Temp
Min
°C
18.3
20.0
21.2
22.4
23.3
23.9
23.5
22.9
22.2
18.6
16.6
14.8
17.7
21.7
16.2
18.3
21.9
22.9
21.7
18.2
16.7
17.4
18.6
18.5
18.7
19.9
18.8
20.0
21.9
21.8
20.0
Rel
Humid
%
77
76
82
68
63
64
67
70
72
79
71
72
76
78
88
79
71
67
79
78
83
82
74
80
91
88
89
73
73
75
100
Solar
Radiation
Cal/cm2
567
594
566
650
626
671
652
631
618
552
673
679
648
523
487
556
614
620
466
495
581
603
616
537
337
375
361
600
602
593
156
Wind
Travel
km
85
51
122
127
127
.
_
_
_
-
127
129
114
174
163
122
154
177
100
298
163
167
48
103
138
71
80
31
130
116
121
TOTAL
Pan
Evap.
mm
5.8
5.3
9.1
8.4
7.9
8.4
8.1
9.1
9.9
11.4
2.3
19.6
1.5
9.4
10.2
5.8
7.1
10.2
7.4
.
-
-
.
11.2
2.5
5.3
3.0
3.0
10.7
9.9
6.9
Gage
mm
1.
12.
3.
9.
2.
5.
17.
18.
69.
Rainfall
1 Gage 2
mm
5 2.5
2 13.7
6 3.6
9 10.7
0 3.8
1 5.1
0 15.7
5 21.6
8 76.7
Runoff
mm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
234
-------
TABLE D-42. DAILY METEOROLOGICAL AND RUNOFF DATA FOR SEPTEMBER, 1979
Date
1
2
3
4
5
6
7
8
9
10
n
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
32.0
30.0
30.5
31.2
31.8
29.2
27.3
29.0
29.0
29.4
28.9
29.8
24.9
22.2
24.2
25.2
27.0
27.9
26.5
22.8
25.2
27.0
29.0
29.9
30.1
30.0
29.4
29.3
32.8
33.9
Temp
Min
°C
18.8
17.6
21.4
21.8
21.8
19.0
18.7
14.5
16.0
16.5
15.3
17.1
14.5
9.4
11.8
9.8
10.8
10.7
15.2
16.5
14.8
10.7
15.1
16.1
16.4
14.9
17.3
18.0
13.0
17.1
Rel
Hunri d
%
83
81
80
76
78
88
71
65
66
71
74
74
64
68
62
59
60
70
81
95
67
58
73
75
65
65
74
70
62
57
Solar
Radiation
Cal/cm?
590
-
516
555
565
357
573
577
577
599
492
471
518
408
571
578
548
526
341
140
420
532
494
493
456
485
470
322
523
471
Wind
Travel
km
121
103
127
51
82
98
90
119
39
130
82
56
117
206
93
45
60
37
61
51
50
113
103
60
121
61
119
145
40
39
TOTAL
Pan
Evap
mm
.
19.6
7.4
7.4
2.0
2.8
15.0
9.1
5.6
5.6
2.8
7.9
9.7
1.8
4.3
7.1
3.3
6.1
3.0
2.0
6.6
4.6
5.3
5.8
6.1
6.6
5.6
12.2
4.3
Rainfall
Gage 1 Gage 2 Runoff
mm mm mm
35.8 33.5 0.00
3.0 8.4 0.00
17.5 18.3 0.00
56.3 60.2 0.00
235
-------
TABLE D-43. DAILY METEOROLOGICAL AND RUNOFF DATA FOR OCTOBER, 1979
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
c
28.3
27.7
22.4
21.5
29.0
27.9
33.1
34.5
14.4
21.0
31.9
26.0
15.6
18.3
20.9
22.1
26.0
28.0
27.7
32.7
29.6
13.5
19.8
25.0
26.2
25.6
24.4
21.9
19.9
19.4
8.8
Temp
Min
ec
13.4
7.7
11.0
6.8
7.6
11.7
14.0
20.6
6.2
2.7
12.2
14.3
7.1
8.5
12.1
14.7
15.1
17.4
19.9
21.5
11.6
5.3
2.7
7.7
8.6
8.7
11.8
6.8
6.9
8.2
4.5
Rel
Humid
%
51
49
48
53
51
48
48
53
63
63
49
58
60
55
84
94
86
77
30
65
82
77
64
51
50
56
71
64
94
90
79
Solar
Radiation
Cal/cma
457
487
381
478
449
461
435
443
250
380
458
386
436
245
172
235
292
346
374
425
314
290
414
410
406
412
360
400
321
84
160
Wind
Travel
km
74
174
148
182
71
167
120
122
347
92
174
88
225
243
224
179
113
100
92
655
433
386
161
50
39
142
124
95
92
360
365
Pan
Evap
mm
. 5.8
10.9
7.6
8.6
6.8
6.3
7.4
7.4
9.1
5.3
7.6
6.6
5.6
5.3
8.6
0.8
1.3
1.5
9.9
5.1
10.9
11.7
2.5
3.0
3.3
4.8
5.6
6.6
5.8
1.5
2.3
TOTAL
Rainfall
Gage 1 Gage 2 Runoff
mm nun nun
14.5 13.2 0.00
11.7 11.7 0.00
11.4 9.9 0.00
37.6 34.8 0.00
236
-------
TABLE D-44. DAILY METEOROLOGICAL AND RUNOFF DATA FOR NOVEMBER, 1979
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Air
Max
°C
12.7
12.0
16.7
17.6
14.6
8.4
7.6
9.7
8.9
4.6
8.0
10.4
12.8
15.9
19.4
21.0
20.3
21.3
23.5
20.0
14.2
4.6
11.1
14.5
13.0
13.0
13.7
1.2
-0.5
6.0
Temp
Min
°C
0.8
3.8
0
6.0
5.4
0.2
-0.2
7.0
1.2
-2.1
-3.8
0.2
-0.9
1.0
2.8
2.2
6.3
13.0
11.5
14.2
1.6
-1.4
-3.0
1.0
2.4
-0.5
-0 2
-2.6
-6.3
-7.1
Rel
Humid
%
67
86
59
54
73
77
97
100
83
75
71
78
67
67
61
60
76
89
70
100
85
80
66
68
78
67
88
73
79
68
Solar
Radiation
Cal/cm2
352
193
384
284
338
362
80
74
181
208
227
264
352
330
352
334
279
221
314
66
272
170
349
304
225
305
213
271
295
233
Wind
Travel
km
188
66
63
88
323
339
69
158
166
254
61
58
72
47
61
95
77
190
286
108
211
259
96
53
106
130
180
183
267
143
TOTAL
Pan Rainfall
Evap Gage 1 Gage 2 Runoff
mm mm mm mm
2.8 3.3 0.00
8.6 8.4 0.00
8.1 6.8 0.00
52.3 54.3 0.83
5.3 5.8 0.01
77.1 78.6 0.84
237
-------
TABLE D-45. DAILY METEOROLOGICAL AND RUNOFF DATA FOR DECEMBER, 1979
Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Air
Max
"C
6.3
6.4
15.0
16.0
16.6
13.7
15.0
9.3
16.7
19.0
12.8
-1.8
7.2
7.6
8.9
1.0
2.0
14.2
15.0
14.7
16.8
19.8
9.8
10.7
14.8
11.8
10.6
9.3
3.4
3.3
7.4
Temp
Min
°C
-3.8
-6.6
-0.7
-1.0
1.9
-2.2
1.8
-2.0
3.0
6.9
-1.4
-4.4
-6.0
-1.1
0.5
-11.3
-16.7
-3.4
-2.0
1.0
2.9
9.7
4.8
1.5
-2.6
3.0
5.2
3.4
2.0
-0.1
-0.3
Rel
Humid
%
72
70
58
66
55
62
58
62
56
83
84
74
68
70
96
63
50
50
75
81
89
63
88
79
73
80
89
100
100
96
91
Solar
Radiation
Cal/cm*
227.9
287.9
258.0
284.8
279.9
251.6
251.4
265.7
111.2
73.5
254.7
202.8
186.6
269.4
311.6
288.5
265.4
266.0
199.0
245.2
76.6
329.2
292.0
206.1
131.7
47.0
60.4
96.4
276.6
Wind Pan
Travel Evap
km mm
53.6
157.7
164.2
104.6
103.0
189.9
117.5
115.9
151.3
183.5
257.5
283.2
334.7
85.3
77.2
186.7
270.4
143.2
49.9
78.8
96.6
82.1
114.2
307.4
78.8
159.3
82.1
215.8
156.1
194.7
119.1
TOTAL
Rainfall
Gage 1 Gage 2 Runoff
mm mm nun
43,18 41.91 0.54
3.81 3.30 0.00
46.99 45.21 0.54
238
-------
r\»
oo
APPENDIX E
SEDIMENT AND NUTRIENT ANALYSIS DATA FOR RUNOFF FROM HYDROLOGIC EVENTS IN 1977, 1978 AND 1979
TABLE E-l. SEDIMENT AND NUTRIENT ANALYSIS OF RUNOFF FROM EVENT OF 20-21 MAY, 1977
Runoff Began: 20 May, 1977
Analysis by: COD and TOC tests
(2120);
by Or. S
Runoff Ended:
. L. Burks
21 May, 1977 (2124); Runoff Amount: 44.27 mm
All other tests
BOD tests by Animal Science Dept.
Sample
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
Time Runoff
Rate
m3/s
2147
2157
2207
2217
2227
2237
2247
2257
2307
2317
2327
2337
2124
(21 May)
1.46
4.12
6.27
4.64
2.54
1.68
1.38
1.26
1.25
1.29
1.32
1.24
0.00
Accum.
Runoff
mm
2.29
4.95
9.96
16.48
20.14
22.17
23.72
25.04
26.34
27.81
29.16
30.58
44.27
Sed
Load
mg/1
1273
3674
2163
2378
1260
693
4869
1052
951
687
618
635
635
N
in Sed.
mg/g
4.8
3.6
3.4
2.6
4.0
6.7
3.1
4.4
5.5
7.5
7.2
10.2
10.2
NH4-N
<0.08
0.04
<0.08
<0.08
0.15
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
N03-N
0.31
0.84
<0.08
0.15
0.23
0.23
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
NO--N Diss.
* P
0.05
<0.01
0.01
0.02
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01
by: Hater testing Laboratory
Agronomy Dept.
Total
P
mg/1
0.05
-
0.01
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Diss.
K
4.5
2.9
2.7
4.3
3.8
3.3
3.0
3.1
3.0
3.0
3. a
3.0
3.0
Total COD
K
40.3
40.1
33.1
26.8
25.8
69.0
27.0
26.0
27.2
26.2
24.2
24.2
TOC
13.5
11.9
11.2
9.4
8.3
10.4
11.4
8.4
9.0
9.5
8.9
9.5
BOD
3.42
2.87
2.10
0.70
-------
rv>
TABLE E-2. SEDIMENT AND NUTRIENT ANALYSIS OF RUNOFF FROM EVENT OF 23 MAY, 1977
Runoff Began: 23 Hay, 1977 (0526); Runoff Ended: 24 Hay. 1977 (1520); Runoff Amount: 13.56 mm
Analysis by: COD and TOC tests by Dr. S. L. Burks
All Other tests by: Water Testing Laboratory
BOD tests by Animal Science Dept.
Sample Time
(lo
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
0538
0548
0558
0608
0618
0628
0638
0648
0658
0708
0718
0728
0738
0748
0808
0831
0900
0925
1004
1053
2400
1520
Runoff
Rate
m3/s
0.06
0.26
0.33
0.29
0.24
0.20
0.15
0.13
0.23
0.41
0.66
0.85
1.09
1.21
0.94
0.54
0.26
0.17
0.10
0.06
0.002
0.00
Accum.
Runoff
run
0.01
0.18
0.58
0.89
1.17
1.35
1.52
1.73
1.90
2.16
2.87
3.56
4.60
5.82
8.03
9.73
10.87
11.46
11.96
12.32
13.21
13.56
Sed.
Load
mg/1
362
1506
1190
819
460
371
278
637
1209
1609
1303
1760
2300
2500
2120
1550
600
380
100
100
100
100
N
In Sed
mg/g
11.3
5.1
6.8
5.9
8.7
10.0
19.4
6.8
6.3
3.9
4.8
_
nn4-N
<0.08
0.23
<0.08
0.53
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
N03-H N02
<0.08
<0.08
<0.08
0.92
0.38
0,61
<0.08
<0.08
<0.08
<0.08
<^0.08
<0.08
,-N Diss.
P
0.25
<0.01
<0.01
<0.01
0.01
<0.01
0.01
<0.01
<0.01
<0.01
0.02
0.04
Agronomy Dept.
Total Diss. Total COD
P K K
mg/1
0.26
<0.02
<0.02
< 0.02f 9»
750IZ)
<0.02m
1100u;
<0.02
<0.02
<0.02
<0.03
<0.05
3.1
3.3
4.6
3.7
4.2
3.8
3.7
3.2
4.5
4.4
4.0
3.0
27.1
34.1
42.4
41.2
45.0
48.6
45.0
48.0
49.9
45.2
40.4
30.95
TOC
14.8
13.4
13.7
15.4
15.9
16.1
16.0
16.3
15.7
14.9
12.8
11.7
BOD
i
1.651
4.75
3.87
2.40
1. All composite samples for BOD are a blend of 3 adjacent samples.
2. High readings of P may have been caused by chunks of organic matter in form of leaves, dung, etc.
3. Sampler capacity exceeded after 0718 hours; all subsequent sediment loads except at 0900 hours are best
estimates based on sediment/runoff rate relationship-
-------
TABLE E-3. SEDIMENT AND NUTRIENT ANALYSIS OF RUNOFF FROM EVENT OF 27 MAY, 1977
ro
. . *
Runoff Began:
: 27 May, 1977 (0210); Runoff Ended: 27 May, 1977 (2200); Runoff Amount: 1.85 mm
Analysis by: COD and TOC
tests by Dr. S.
L. Burks All other tests by: Water Testing Laboratory
BOD tests by Animal Science Dept.
Sample
No.
1
2
3
4
5
6
7
8
9
10
Time
0222
0242
0302
0322
0342
0402
0422
0442
0502
2200
Runoff
Rate
m3/s
0.032
0.105
0.118
0.114
0.093
0.073
0.053
0.041
0.028
0.000
Accum.
Runoff
mm
0.01
0.04
0.12
0.66
0.86
1.04
1.17
1.27
1.35
1.85
Sed.
Load
mg/1
2132
1315
802
261
316
238
223
196
217
68
N
in Sed
mg/g
1.2
4.9
6.9
9.1
14.1
12.1
19.3
21.9
20.3
57.8
NH4-N
<0.08
<0.08
<0.08
0.92
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
N03-N N02-N
<0.08
0.15
0.15
0.69
0.53
0.53
<0.08
<0.08
<0.08
<0.08
Diss.
P
0.01
<0.01
0.01
0.01
0.01
0.01
0.01
0.02
0.01
0.02
Agronomy Dept.
Total
P
mg/1
0.01
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.03
<0.02
<0.03
Diss. Total
K K
3.9
3.5
4.8
5.3
5.6
4.8
4.8
4.4
5.0
4.6
COD
37.3
45.6
50.9
54.2
54.6
47.7
43.1
33.6
TOC
16.1
14.5
18.0
19.7
20.2
20.0
20.4
20.2
20.4
20.5
BOD
6.53
6.25
6.70
-------
TABLE E-4. SEDIMENT AND NUTRIENT ANALYSIS OF RUNOFF FROM EVENT OF 1 JULY, 1977
INJ
4^
ro
Runoff Began
Analysis by:
: 1 July, 1977 (0454);
TOC tests by Or
. S. L.
Runoff Ended: 1 July, 1977 (1400);
Burks
All other tests by:
Runoff
Amount: 1 .72 mm
Water testing iaboratory
Agronomy Dept.
Sample
No.
1
2
3
4
5
6
7
8
_
Time
0502
0523
0543
0602
0622
0643
0703
0723
1400
Runoff
Rate
m3/s
0.29
0.30
0.11
0.61
0.28
0.02
0.12
0.01
0.00
Accum.
Runoff
mm
0.11
0.84
1.27
1.40
1.52
1.58
1.60
1.63
1.72
Sed.
Load
mg/1
1760
2515
1841
1322
1153
889
853
734
734
N
In Sed
mg/g
10.3
4.1
4.0
5.0
4.4
6.8
6.0
5.6
N04-H
NO,-N NO,-N 01 ss. Total 01 ss. Total
J ' P P K K
COD TOC BOO
mg/1
< 0.08
< 0.08
< 0.08
< 0.08
< 0.08
< 0.08
< 0.08
< 0.08
0.08
< 0.08
< 0.08
< 0.08
< 0.08
< 0.08
< 0.08
< 0.08
0.01
0.02
0.02
0.03
0.04
0.06
0.04
0.07
3
2
3
2
2
3
3
3
.8
.9
.0
.8
.8
.1
.0
.5
14.8
14.2
13.6
13.0
13.8
13.2
14.1
13.3
-------
TABLE E-5. SEDIMENT AND NUTRIENT ANALYSIS OF RUNOFF FROM EVENT OF 5 JUNE, 1978
Runoff Began: 5 June, 1978
Analysis by: Nitrogen
Sample Time
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
0554
0604
0613
0622
0630
0640
0648
0702
0718
0740
0807
0833
0904
1400
Runoff
Rate
m3/s
0.057
0.555
0.685
0.645
0.608
0.385
0.284
0.203
0.130
0.085
0.053
0.036
0.024
0.000
Accum. Sed.
Runoff Load
mm mg/1
0.005
0.381
0.889
1.600
2.134
2.540
2.845
3.175
3.454
3.708
3.886
4.013
4.115
4.420
(0550); Runoff Ended: 5 June, 1978 (1400); Runoff Amount: 4.42
tests by:
Dr. D. W. Toetz.
N NH.-H
in Sed.
mg/g
0
0
0
0
0
.425
.254
.191
.351
.127
0.092
0
0
0
0
0
0
0
0
.097
.096
.147
.170
.166
.193
.207
.012
N03-N NO,
0.023
0.298
0.105
0.081
0.139
0.031
0.095
0.029
0.029
0.021
0.019
0.023
0.019
0.020
mm
All other tests by: Or. S. L. Burks.
,-N Diss.
i P
0.000
0.035
0.024
0.083
0.000
0.005
0.002
0.059
0.073
0.002
0.047
0.026
0.035
0.012
Total Oiss. Total
P K K
mg/1
0.083
0.750
0.035
0.120
0.000
0.012
0.153
0.023
0.087
0.002
0.035
0.073
0.038
0.024
15.58
31.65
27.99
27.18
28.37
20.50
25.74
10.82
10.82
8.36
6.88
6.88
6.06
5.08
COD
80.6
102.4
140.3
123.4
89.5
79.8
68.5
65.9
57.9
56.1
50.4
52.0
52.0
53.7
TOC
20.45
15.58
16.22
16.10
15.30
14.58
15.32
13.88
14.38
16.72
17.55
17.82
17.17
20.53
-------
TABLE E-6. SEDIMENT AND NUTRIENT ANALYSIS OF RUNOFF FROM EVENT OF 21-22 JUNE, 1978
Runoff Began
: 21 June, 1978 (1810); Runoff Ended: 22 June,
1978 (0140); Runoff Amount: 0.09 mm
Analysis by: Nitrogen tests by: Or. D. W. Toetz. All other tests by:
Sample
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
--
Time
1842
1854
1903
1912
1922
1931
1940
1950
1958
2008
2016
2026
2035
0140
Runoff
Rate
m3/s
0.001
0.002
0.003
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.003
0.003
0.002
0.000
Accum.
Runoff
mm
0.003
0.005
0.008
0.010
0.013
0.018
0.020
0.025
0.030
0.033
0.036
0.038
0.046
0.091
Sed N NH.-N
Load in Sed
mg/1 mg/g
0.060
N D
0.010
0.042
0.066
0.046
N D
N D
0.044
0.034
0.046
0.062
0.152
N03-N
0.134
0.113
0.128
0.117
0.113
0.117
0.217
0.128
0.119
0.111
0.126
0.109
0.115
N02-N
0.024
0.014
0.017
0.014
0.016
0.019
0.017
0.019
0.021
0.014
0.013
0.015
0.008
Diss.
P
0.051
0.000
0.014
0.037
0.000
0.005
0.005
0.051
0.007
0.049
0.044
0.119
0.096
Total
P
mg/1
0.096
0.005
0.084
0.140
0.051
0.014
0.061
0.061
0.021
0.049
0.086
0.037
0.021
Dr. S. L. Burks.
Diss. Total
K K
15.59
24.54
12.94
19.25
22.71
18.23
21.49
17.22
22.30
17.42
21.89
22.10
21.49
COD
74.3
66.5
82.1
78.2
74.3
74.3
78.2
78.2
74.3
74.3
74.3
70.4
62.6
TOC
29.98
29.16
30.31
30.15
29.49
30.15
31.30
31.46
29.49
28.18
31.38
33.51
30.22
-------
TABLE E-7. SEDIMENT AND NUTRIENT ANALYSIS OF RUNOFF FROM EVENT OF 14-15 NOVEMBER, 1978
Runoff Began:
Analysis
Sample Time
No.
, 1
2
3
4
ro
01 5
6
7
8
9
10
1923
1936
1947
1956
2006
2016
2026
2036
2045
2055
Runoff
Rate
m3/s
0.006
0.089
0.109
0.105
0.085
0.069
0.057
0.049
0.041
0.028
14 November, 1978 (1923); Runoff Ended: 15 November.
by: Nitrogen tests by: None Made . All other te
Accum.
Runoff
iran
0
0
0
0
0
0
0
0
0
0
.003
.066
.180
.284
.386
.457
.533
.584
.635
.660
Sed. N NH.-N
Load in Sed.
mg/1 mg/g
562
865
813
807
866
885
807
787
729
657
NO,-N NO,-N Diss.
J Z p
-
-
-
-
0.107
0.021
0.081
0.032
0.001
0.047
1978 (0820), Runoff Amount: 0.94 mm
sts by Di
Total
P
mg/1
0.081
0.100
0.089
0.005
0.191
0.089
0.087
0.055
0.001
0.087
r. S. L
Oiss.
K
3.88
4.22
3.94
3.74
4.15
3.26
3.54
3.60
3.19
3.54
. Burks.
Total
K
10.82
14.91
14.46
13.58
-
16.16
14.90
13.10
15.58
14.39
COD
70.2
116.6
61.2
57.6
57.6
54.0
66.9
52.5
56.8
70.7
TOC
36.2
37.8
29.9
30.6
30.6
30.6
30.6
27.7
27.7
28.8
(Continued)
-------
TABLE E-7 (Continued)
en
Runoff Began: 14 November, 1978 (1923); Runoff
Ended: 15 November
Analysis by: Nitrogen tests by: None Hade . All other
Sample
No.
11
12
13
14
15
16
17
18
19
Time Runoff
Rate
m3/s
2105
2115
2125
2135
2146
2157
2209
2221
0820
(15 Nov.
0.024
0.020
0.016
0.012
0.012
0.010
0.009
0.007
0.000
Accum.
Runoff
nm
0.706
0.711
0.737
0.762
0.770
0.782
0.792
0.803
0.940
Sed. N NH.-N
Load In Sed.
mg/1 mg/g
662
595
642
579
586
621
513
545
370
, 1978 (0820),
tests
NO,-N NO,-N 01 ss.
J * P
0
0
0
.173
.099
.095
0.064
0
<0
0
0
0
.039
.002
.066
.081
.096
Runoff Amount:
0.94 RTO
by Dr. S. L. Burks.
Total
P
mg/1
0.252
0.032
0.095
0.064
<0.002
0.084
0.211
0.089
0.096
Diss.
K
3.47
3.33
3.19
3.12
3.12
2.92
3.19
3.33
4.36
Total
K
13.13
12.48
11.33
11.77
11.43
11.39
12.69
11.46
10.96
COD
68.8
78.7
57.6
56.8
57.2
57.6
57.6
59.5
. 56.5
TOC
25.9
26.4
27.1
25.6
26.5
25.9
25.2
25.7
28.30
-------
TABLE E-8. SEDIMENT AND NUTRIENT ANALYSIS OF RUNOFF FROM EVENT OF 18 MARCH, 1979
ro
Runoff Began
: 18 March, 1979 (1046): Runoff
Analysis by: Nitrogen
Sample
No
1
2
3
4
5
6
7
8
Grab<2>
Time
1101
1133
1213
1318
1430
1548
1843
2200
Runoff
Rate
m3/s
0.016
0.028
0.020
0.008
0.002
0.001
0.000
0.000
Accum.
Runoff
mm
0.005
0.076
0.305
0.483
0.508
0.317
0.533
0.559
Sed
Load
mg/1
1823
3760
1984
1332
980
736
616
508
132
Ended: 18 March. 1979
tests by: Dr. D. W. Toetz. All
N NH.-N
in Sed q
mg/g
0.771 0.654
0.708 0.806
0.640 0.625
0.992. 0.515
6.991 0.821
0.664 0.225
3.199(1)0.797
1.782^0.897
1.511^)0.539
N03-N
0.141
0.245
0.198
0.134
0.147
0.145
0.074
0.064
1.987^
N02-N
0.008
0.011
0.011
0.008
0.007
0.007
0.006
0.006
0.093^
(2200). Runoff Amount: 0.56 mm
other tests by
Diss.
P
0.005
0.167
0.108
0.105
0.106
0.153
0.089
0.126
0.055
Total
P
mg/1
0.492
0.302
0.468
0.420
0.348
0.364
0.313
0.306
0.140
Dr. S. L
Diss.
K
3.46
3.28
2.92
3.10
3.46
3.46
3.28
3.46
1.66
.. Burks.
Total
K
26.53
37.30
27.60
21 . 15
16.84
12.07
9.20
8.49
2.38
COD
184.0
211.8
177.1
107.6
73.0
128.6
100.7
55.5
66.0
TOC
73.1
85.4
56.6
37.0
35.7
34.3
27.0
30.6
13.0
Notes:
1. Values of N for these three samples appear to be very high with no readily apparent explanation.
2. This grab sample was obtained from the H-flume at the southeast corner of the exclosure located
in the southwest corner of the watershed. Note that this 1s the exclosure from which cows had
been excluded and dung had been physically removed.
-------
TABLE E-9. SEDIMENT AND NUTRIENT ANALYSIS OF RUNOFF FROM EVENT OF 22-23 MARCH, 1979
: Runoff Began
Analys
1
Sample
No
1
2
3
4
ro
oo 5
6
7
8
9
10
Grab
Time
0528
0546
0606
0637
0710
0737
0813
0339
1430
1400
(23 Mar.;
Runoff
Rate
m3/s
0.146
0.304
0.539
0.896
1.220
0.766
0.430
0.308
0.008
0.000
I
: 22 March, 1979 (0500)
is by: Nitrogen
Ac cum.
Runoff
mm
0.076
0.559
1.448
3.759
7.061
10.262
12.497
13.513
15.697
16,434
Sed
Load
mg/1
1104
3469
2808
3788
3828
2544
1429
756
236
108
172
tests bj
N
in Sed
mg/g
0.587
0.612
0.726
0.626
0.567
0.592
0.641
0.462
N D
0.455
1.023
, Runoff Ended: 23 March 1979 (1400), Runoff Amount: 16.43 mm.
r- Dr. D. W. Toetz. All other tests by: Dr. S.
NH4-N
0.434
0.806
0.539
1.007
0.501
0.597
0.453
0.754
0.129
0.058
0.606
N03-H
0.022
0.029
0.029
0.048
0.041
0.046
0.042
0.064
0.061
0.119
0.039
N02-N
0.001
0.004
0.006
0.007
0.007
0.007
0.006
0.006
0.004
0.003
0.004
Diss.
P
0.065
0.089
0.107
0.137
0.125
0.028
0.069
0.081
0.014
0.026
0.014
Total
P
mg/1
0.528
0.671
0.607
0.677
0.589
0.529
0.416
0.292
0.165
0.129
0.183
Diss.
K
3.28
3.10
2.74
2.38
2.02
2.02
2.38
2.57
3.64
3.99
3.82
L. Burks.
Total
K
11.72
25.45
20.07
27.07
19.53
8.48
9.02
6.69
2.74
1.66
2.56
COD
108.4
228.9
164.6
192.8
124.5
120.5
-
40.2
28.1
28.1
28.1
TOC
46.3
65.7
58.6
70.7
40.3
30.2
30.2
25.0
38.1
21.1
-------
TABLE E-10. SEDIMENT AND NUTRIENT ANALYSIS OF RUNOFF FROM EVENT OF 2-7 MAY, 1979
Runoff Began: 2 Hay, 1979 (0852); Runoff Ended: 7 May. 1979 (1730); Runoff Amount: 32.03 mn
ro
-P»
10
Analysis by: Nitrogen tests:
Sample Time
No
1 0904
2 0914
3 0924
4 0932
5 0954
6 1017
7 1047
8 1112
9 1152
10 2034
1 1 2038
12 2050
13 2057
14 2110
15 2120
16 2134
17 2152
18 2207
19 2222
20 2252
21 2254
(2 May)
Grab 0)l315
Grab (2)1320
Grab (3)1325
Grab (4)1330
(3 Hay)
Runoff Accum.
Rate Runoff
»
m /s mm
0.105 0.076
0.138 0.203
0.134 0.356
0.122 0.457
0.093 0.711
0.077 0.889
0.065 1.118
0.073 1.295
0.065 1.600
1.707 4.191
1.808 4.928
1.480 6.985
1.168 7.950
0.722 9.246
0.539 9.906
J.373 10.592
0.264 11.176
0.203 11.532
0.162 11.811
0.097 12.192
0.093 12.243
Pasture
Pasture
Road Ditch
Exclosure
Sed.
Load
mg/1
1482
2058
2253
2032
1248
721
'501
415
254
1967
5484
5167
3239
2242
1556
1337
796
520
721
319
280
19
134
1923
21
N
in Sed.
mg/g
1.71
1.68
1.52
2.07
2.17
3.79
3.75
3.32
3.47
1.81
1.22
1.69
2.44
1.57
1.28
1.91
1.94
6.01
2.36
2.12
2.70
11.03
10.45
0.97
6.88
Dr. D.
NH.-N
M
0.441
0.462
0.343
0.511
0.283
0.426
0.418
0.250
0.371
0.264
0.274
0.223
0.331
0.289
0.248
0.102
0.050
0.078
0.052
0.250
0.034
0.240
0.066
0.191
0.184
W. Toetz. All
NO,-N
J
0.053
0.080
0.099
0.092
0.073
0.053
0.031
0.032
0.039
. 0.009
0.009
0.011
0.013
0.013
0.010
0.009
0.007
0.012
0.012
0.008
0.009
0.019
0.018
0.024
0.016
NO,-N
C
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
other tests by:
Diss.
P
0.330
0.221
0.225
0.248
0.248
0.170
0.194
0.227
0.227
0.140
0.075
0.103
0.022
0.070
0.070
0.100
0.062
0.077
0.286
0.125
0.115
0.057
0.052
0.012
0.027
Total
P
mg/1
0.438
0.533
0.533
0.601
0.533
0.506
0.411
0.379
0.330
0.631
0.778
0.745
0.698
0.679
0.508
0.409
0.466
0.328
0.229
0.366
0.366
0.002
0.153
0.461
0.002
Dr. S.
Diss.
K
5.36
5.61
4.20
3.54
5.28
4.20
4.12
4.04
4.37
3.51
3.05
2.86
2.36
2.55
2.42
2.74
2.74
2.74
3.87
2.61
2.86
2.86
2.61
2.24
3.81
L. Burks
total
K
17.55
17.32
17.79
16.57
16.99
14.79
13.39
10.89
7.24
14.30
28.60
30.19
21.72
14.83
13.77
12.18
7.42
5.30
4.50
2.65
3.18
3.24
4.03
10.65
5.09
COD
122.8
122.8
130.2
130.2
119.0
93.0
85.6
81.8
78.1
167.4
290.2
235.6
152.5
122.8
81.8
81.8
70.7
59.5
55.8
59.5
85.6
40.9
63.2
126.5
63.2
TOC BOD
34.1
44.1
45.8
43.2
45.0
34.5
33.3
28.7
29.0
55.9
69.6
46.5
51.2
39.6
31.3
33.7
22.7
22.5
20.4
23.3
19.5
16.1
25.4
35.6
26.3
(Continued)
-------
ro
in
O
Notes:
TABLE E-10 (Continued)
1. Sample obtained from water flowing through grass in a small natural drainageway 50 m south of soil
water station 27; no visible erosion in channel or upstream area.
2. Sample obtained from a small ponded area in a natural surface depression 5cmx3mx5m located
90 m east of soil water station 27; no visible erosion in surrounding area.
3. Sample obtained from water flowing in field road ditch at transit station 120 m north of soil water
station 16; represents runoff from recently graded field road.
4. Sample obtained from outflow from H flume located 90 m northeast of soil water station 17; represents
runoff from an exclosure from which cows had been excluded and dung had been physically removed.
-------
APPENDIX F
COMPUTATION OF SEDIMENT LOST BY RUNOFF FROM HYDROLOGIC
EVENTS IN 1977, 1978 AND 1979
TABLE F-l. SEDIMENT LOST BY RUNOFF FROM EVENT OF 20 MAY, 1977
Rainfall: 101.55 mm Runoff: 44.27 mm
Sediment/Runoff Ratio: 15.53 kq/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
m /s mm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
9
10
11
12
13
2147 1.456
2157 4.115
2207 6.268
2217 4.638
2227 2.538
2237 1.675
2247 1.379
2257 1.261
2307 1 .249
2317 1.293
2327 1.322
2337 1.245
2124 0.000
(21 May)
9.12
25.78
39.27
29.06
15.90
10.49
8.64
7.90
7.82
8.10
8.28
7.80
0.00
2.28
4.95
9.95
16.48
20.14
22.17
23.72
25.04
26.34
27.81
29.15
30.59
44.27
1273
3674
2163
2378
1260
693
4869
1052
951
687
618
635
635
29.10
65.96
146.. 03
148.21
66.53
19.84
43.08
39.10
12.97
12.06
8.78
8.91
86.93
29.10
95.06
241.10
389.31
455.85
475.69
518.78
557.88
570.85
582.92
591.70
600.61
687.55
251
-------
TABLE F-2. SEDIMENT LOST BY RUNOFF FROM EVENT OF 23 MAY, 1977
Rainfall: 38.50 mm Runoff: 13.56 mm
Sediment/Runoff Ratio: 14.28 kq/ha/mm
.Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
m /s nm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
0538
0548
0558
0608
0618
0628
0638
0648
0658
0708
0718
0728
0738
0748
0808
0831
0900
0925
1004
1053
2400
1520
(24 May)
0.057
0.259
0.332
0.292
0.235
0.203
0.146
0.134
0.227
0.414
0.657
0.851
1.091
1.208
0.941
0.539
0.264
0.166
0.097
0.057
0.002
0.000
0.36
1.63
2.08
1.83
1.47
1.27
0.91
0.84
1.42
2.59
4.11
5.33
6.83
7.57
5.89
3.38
1.65
1.04
0.61
0.36
0.01
0.00
0.01
0.17
0.58
0.88
1.16
1.34
1.52
1.72
1.90
2.15
2.87
3.55
4.59
5.81
8.02
9.72
10.87
11.45
11.96
12.31
13.20
13.56
362
1506
1190
819
460
371
278
637
1209
1609
1700
1760
2300
2500
2120
1550
600
380
100
100
100
100
0.03
1.56
5.47
3.06
1.78
0.73
0.57
0.93
1.64
3.57
11.76
11.86
21.14
29.26
51.04
31.22
12.28
2.86
1.21
0.35
0.88
0.35
0.03
1.60
7.08
10.14
11.92
12.66
13.24
14.17
15.81
19.39
31.16
43.02
64.16
93.42
144.47
175.70
187.98
190.85
192.07
192.42
193.31
193.67
252
-------
TABLE F-3. SEDIMENT LOST BY RUNOFF FROM EVENT OF 27 MAY, 1977
Rainfall: 22.35 mm Runoff: 1.85 mm
Sediment/Runoff Ratio: 3.75 kg/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
m /s mm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
9
10
0222
0242
0302
0322
0342
0402
0422
0442
0502
2200
0.032
0.105
0.118
0.114
0.093
0.073
0.053
0.041
0.028
0.000
0.20
0.66
0.74
0.71
0.58
0.46
0.33
0.25
0.18
0.00
0.01
0.04
0.12
0.66
0.86
1.04
1.16
1.27
1.34
1.85
2132
1315
802
261
316
238
223
196
217
68
0.27
0.52
0.83
2.86
0.58
0.49
0.29
0.21
0.15
0.72
0.27
0.79
1.63
4.49
5.07
5.57
5.86
6.07
6.23
6.95
TABLE F-4. SEDIMENT LOST BY RUNOFF FROM EVENT OF 1 JULY, 1977
Rainfall: 45.72 mm Runoff: 1.72 mm
Sediment/Runoff Ratio: 18.68 kg/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate ' Rate Runoff in Sample Interval Sed. Loss
m /s mm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
9
0502
0523
0543
0602
0622
0643
0703
0723
1400
0.288
0.304
0.114
0.061
0.028
0.016
0.012
0.008
0.000
1.80
1.90
0.71
0.38
0.18
0.10
0.08
0.05
0.00
0.14
0.84
1.27
1.39
1.52
1.57
1.60
1.62
1.71
1760
2515
1841
1322
1153
889
853
734
734
2.01
15.58
9.29
2.00
1.57
0.51
0.22
0.20
0.67
2.01
17.59
26.88
28.89
30.46
30.98
31.20
31.40
32.08
253
-------
TABLE F-5. SEDIMENT LOST BY RUNOFF FROM EVENT OF 14 NOVEMBER, 1978
Rainfall: 47.75 mm Runoff: 0.94 mm
Sediment/Runoff Ratio: 7.30 kg/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
m /s mm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
1923
1936
1947
1956
2006
2016
2026
2036
2045
2055
2105
2115
2125
2135
2146
2157
2209
2221
0820
(15 Nov)
0.006
0.089
0.109
0.105
0.085
0.069
0.057
0.049
0.041
0.028
0.024
0.020
0.016
0.012
0.012
0.010
0.009
0.007
0.000
0.04
0.56
0.69
0.66
0.53
0.43
0.36
0.30
0.25
0.18
0.15
0.13
0.10
0.08
0.07
0.06
0.05
0.05
0.00
0.00
0.06
0.18
0.28
0.38
0.45
0.53
0.58
0.63
0.66
0.70
0.71
0.73
0.76
0.77
0.78
0.79
0.80
0.94
562
865
813
807
866
885
807
787
729
657
662
595
642
579
586
621
513
545
370
0.01
0.45
0.95
0.84
0.85
0.62
0.64
0.40
0.38
0.17
0.30
0.03
0.15
0.15
0.04
0.07
0.05
0.05
0.62
0.01
0.46
1.42
2.27
3.12
3.74
4.38
4.79
5.17
5.35
5.65
5.68
5.84
5.99
6.04
6.12
6.17
6.23
6.85
254
-------
TABLE F-6. SEDIMENT LOST BY RUNOFF FROM EVENT OF 18 MARCH, 1979
Rainfall: 20.32 iron Runoff: 0.56 mm
Sediment/Runoff Ratio: 21.21 kg/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
m /s mm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
1101
1133
1213
1318
1430
1548
1843
2200
0.016
0.028
0.020
0.008
0.002
0.001
0.000
0.000
0.10
0.18
0.13
0.05
0.01
0.01
0.00
0.00
0.00
0.07
0.30
0.48.
0.50
0.31
0.53
0.55
1828
3760
1984
1332
980
736
616
508
0.09
1.98
6.56
2.94
0.29
1.63
1.45
0.14
0.09
2.08
8.64
11.59
11.88
10.25
11.71
11.85
TABLE F-7. SEDIMENT LOST BY RUNOFF FROM EVENT OF 22 MARCH, 1979
Rainfall: 55.37 mm Runoff: 16.43 mm
Sediment/Runoff Ratio: 25.03 kg/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
m /s mm/h mm mg/1 kg/ha kg/ha
.1
2
3
4
5
6
7
8
9
10
0528
0546
0606
0637
0710
0737
0813
0839
1430
1400
0.146
0.304
0.539
0.896
1.220
0.766
0.430
0.308
0.008
0.000
0.91
1.90
3.38
5\ 61
7.65
4.80
2.69
1.93
0.05
0.00
0.07
0.55
1.44
3.75
7.06
10.26
12.49
13.51
15.69
16.43
1104
3469
2808
3788
3828
2544
1429
758
236
108
0.84
11.03
27.90
76.23
125.74
.101.96
44.40
11.10
10.83
1.26
0.84
11.87
39.77
116.00
241.74
343.71
388.11
399.21
410.04
411.31
(23 March)
255
-------
TABLE F-8. SEDIMENT LOST BY RUNOFF FROM EVENT OF 10 APRIL, 1979
Rainfall: 26.92 mm Runoff: 1.85 mm
Sediment/Runoff Ratio: 18.70 kq/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. .Loss
m /s mm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
1822
1836
1840
1854
1906
1914
1924
1934
1945
1952
2000
2008
2016
2024
2032
2040
2056
2105
2113
2122
2135
2152
2208
2230
1600
(11 April
0.211
0.264
0.243
0.170
0.126
0.105
0.081
0.061
0.049
0.045
0.041
0.036
0.028
0.024
0.024
0.020
0.016
0.016
0.012
0.012
0.010
0.009
0.008
0.006
0.000
)
1.32
1.65
1.52
1.07
0.79
0.66
0.51
0.38
0.30
0.28
0.25
0.23
0.18
0.15
0.15
0.13
0.10
0.10
0.08
0.08
0.06
0.05
0.05
0.04
0.00
0.10
0.48
0.58
0.88
1.06
1.16
1.27
1.34
1.39
1.44
1.47
1.49
1.52
1.54
1.57
1.60
1.62
1.64
1.65
1.66
1.68
1.70
1.71
1.73
1.85
2302
2420
3260
2307
2134
1852
1546
1159
1045
990
876
714
648
682
631
596
547
492
462
457
438
378
438
361
361
2.33
8.99
2.88
8.48
3.94
2.02
1.72
1.03
0.56
0.51
0.23
0.20
0.17
0.16
0.16
0.15
0.14
0.09
0.06
0.05
0.06
0.07
0.05
0.06
0.44
2.33
11.33
14.22
22.70
26.65
28.67
30.40
31.43
31.99
32.51
32.74
32.94
33.12
33.29
33.45
33.61
33.75
33.85
33.91
33.97
34.03
34.11
34.16
34.22
34.67
256
-------
TABLE F-9. SEDIMENT LOST BY RUNOFF FROM EVENT OF 2-3 MAY, 1979
Rainfall: 99.31 mm Runoff: 32.03 mm
Sediment/Runoff Ratio: 10.55 kq/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
3
m /s mm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
0904
0914
0924
0932
0954
1017
1047
1112
1152
2034
2038
2050
2057
2110
2120
2134
2152
2207
2222
2252
2254
(2 May)
0.105
0.138
0.134
0.122
0.093
0.077
0.065
0.073
0.065
1.707
1.808
1.480
1.168
0.722
0.539
0.373
0. 264
0.203
0.162
0.097
0.093
0.66
0.86
0.84
0.76
0.58
0.48
0.41
0.46
0.41
10.69
11.33
9.27
7.32
4.52
3.38
2.34
1.65
1.27
1.02
0.61
0.58
0.07
0.20
0.35
0.45
0.71
0.88
1.11
1.29
1.60
4.19
4.92
6.98
7.95
9.24
9.90
10.59
11.17
11.53
11.81
12.19
12.24
1482
2058
2253
2032
1248
721
501
415
254
1967
5484
5167
3239
2242
1556
1337
796
520
721
319
280
1.12
2.24
3.28
2.17
4.16
1.75
1.39
0.81
1.02
28.77
27.44
109.56
40.56
35.50
12.54
9.92
6.23
2.34
1.73
1.98
0.15
1.12
3.37
6.66
8.83
13.00
14.75
16.15
16.96
17.98
46.75
74.19
183.76
224.33
259.83
272.37
282.29
288.52
290.86
292.59
294.57
294.73
(Continued)
257
-------
TABLE F-9. (Continued)
Rainfall: 99.31 mm Runoff: 32.03 mm
Sediment/Runoff Ratio: 10.55 kq/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
m /s mm/h mm mg/1 kg/ha kg/ha
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
1345
1544
1552
1600
1608
1616
1623
1630
1638
1647
1654
1702
1710
1718
1726
1732
1741
1749
1757
1805
1812
1819
1826
1834
1842
(3 May)
1730
(7 May)
0.053
0.158
0.219
0.251
0.284
0.304
0.308
0.304
0.284
0.268
0.243
0.219
0.195
0.178
0.158
0.146
0.130
0.122
0.118
0.109
0.109
0.109
0.122
0.138
0.166
0.000
0.33
0.99
1.37
1.57
1.78
1.90
1.93
1.90
1.78
1.68
1.52
1.37
1.22
1.12
0.99
0-.91
0.81
0.76
0.74
0.69
0.69
0.69
0.75
0.86
1.04
o.oo
14.19
15.51
15.67
15.87
16.07
16.33
16.56
16.78
17.01
17.29
17.47
17.67
17.83
17.98
18.13
>8.23
18.36
18.46
18.56
18.66
18.74
18.82
18.89
19.02
19.15
32.02
61
293
412
482
488
580
593
546
462
432
397
352
317
328
318
306
249
259
249
205
240
232
228
224
210
150
3.33
2.33
0.53
0.90
0.98
1.35
1.34
1.30
1.15
1.24
0.73
0.76
0.51
0.49
0.49
0.31
0.35
0.25
0.25
0.23
0.17
0.18
0.17
0.28
0.27
23.18
298.06
300.40
300.94
301.84
302.83
304.19
305.53
306.83
307.98
309.23
309.97
310.73
311.24
311.73
312.22
312.54
312.89
313.15
313.40
313.64
313.80
313.98
314.16
314.45
314.72
337.90
258
-------
TABLE F-10. SEDIMENT LOST BY RUNOFF FROM EVENT OF 9 JUNE, 1979
Rainfall: 75.95mm Runoff: 8.76mm
Sediment/Runoff Ratio: 14.38 kq/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
m /s mm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
0227
0237
0243
0253
0301
0311
0319
0327
0335
0343
0350
0358
0405
0414
0836
0844
0852
0900
0909
0917
0926
0934
0941
0949
1502
0.896
1.074
0.851
0.633
0.414
0.296
0.215
0.142
0.109
0.097
0.081
0.069
0.057
0.049
0.414
0.397
0.385
0.369
0.357
0.296
0.239
0.215
0.191
0.146
0.000
5.61
6.73
5.33
3.96
2.59
1.85
1.35
0.89
0.69
0.61
0.51
0.43
0.36
0.30
2.59
2.49
2.41
2.31
2.24
1.85
1.50
1.35
1.19
0.91
0.00
0.25
1.17
1.85
2.56
3.28
3.66
3.86
4.11
4.22
4.27
4.32
4.37
4.42
4.47
5.13
5.41
5.69 -
5.99
6.27
6.86
6.91
7.01
7.14
7.54
8.76
4044
3341
2740
1671
1215
930
832
707
514
548
472
452
406
375
440
1154
1329
1043
782
586
532
424
350
366
350
10.27
33.76
20.85
15.69
10.26
4.09
1.79
1.95
0.62
0.27
0.26
0.23
0.22
0.20
2.69
2.23
3-. 47
3.61
2.55
4.00
0.00
0.73
0.49
1.45
4.36
10.27
44.03
64.88
80.57
90.83
94.92
96.71
98.66
99.28
99.55
99.81
100.04
100.26
100.46
103.15
105.38
108.85
112.46
115.01
119.01
119.01
119.74
120.23
121.68
126.04
259
-------
TABLE F-ll. SEDIMENT LOST BY RUNOFF FROM EVENT OF 5 JULY, 1979
Rainfall: 52.07 mm Runoff: 2.36 mm
Sediment/Runoff Ratio: 10.98 kq/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
m /s mm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
9
10
2224
2234
2243
2249
2257
2305
2314
2322
2330
1820
0.187
0.187
0.158
0.130
0.097
0.081
0.069
0.061
0.053
0.000
1.17
1.17
0.99
0.81
0.61
0.51
0.43
0.38
0.33
0.00
0.14
0.35
0.50
0.58
0.68
0.76
0.83
0.88
0.94
2.36
2355
2310
1981
1622
1506
1342
1238
1100
1001
150
3.35
4.97
3.27
1.37
1.58
1.08
0.98
0.59
0.53
8.18
3.35
8.32
11.59
12.96
14.55
15.64
16.62
17.22
17.75
25.93
(7 July)
260
-------
TABLE F-12. SEDIMENT LOST BY RUNOFF FROM EVENT OF 17 JULY, 1979
Rainfall: 82.55 mm Runoff: 23.47 mm
Sediment/Runoff Ratio: 31.43 kg/ha/mm
Sample Time Runoff Runoff Accum. Sed. Load Sed. per Accum.
No. Rate Rate Runoff in Sample Interval Sed. Loss
m /s mm/h mm mg/1 kg/ha kg/ha
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
0332
0338
0346
0356
0403
0411
0418
0424
0433
0441
0448
0456
0503
0512
0520
0527
0534
0541
0549
0556
0602
0611
0619
0626
1930
(19 July)
2.749
4.395
4.634
3.463
2.494
1.638
1.143
0.896
0.685
0.539
0.458
0.373
0.332
0.304
0.268
0.251
0.231
0.211
0.195
0.178
0.162
0.146
0.134
0.122
0.000
17.22
27.53
29.03
21.69
15.62
10.26
7.16
5.61
4.29
3.38
2.87
2.34
2.08
1.90
1.68
1.57
1.45
1.32
1.22
1.12
1.02
0.91
0.84
0.76
0.00
1.70
4.08
7.95
12.11
14.30
16.02
17.04
17.67
18.41
18.92
19.30
19.63
19.91
20.21
20.44
20.62
20.82
20.98
21.15
21.28
21.38
21.53
21.64
21.74
23.47
8604
5422
2800
2586
2188
2024
1732
1515
1140
1019
838
715
644
571
542
453
442
416
357
372
336
314
276
255
159
146.42
167.44
158.71
112.18
52.14
36.37
19.08
10.30
9.77
5.48
3.53
2.56
1.89
1.85
1.27
0.88
0.90
0.65
0.68
0.46
0.36
0.49
0.30
0.27
3.57
146.42
313.86
472.58
584.76
636.90
673.27
692.35
702.66
712.44
717.92
721.46
724.03
725.92
727.78
729.05
729.93
730.84
731.50
732.18
732.65
733.01
733.50
733.80
734.07
737.64
261
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APPENDIX G
SOIL PROFILE DESCRIPTIONS OF SAMPLING LOCATIONS
Location No. 1
A 1 0 - 23 cm - Very dark grayish brown (10YR 3/2) moist; loam;
weak medium subangular blocky breaking to weak fine
granular structure; friable when moist; common medium
size roots; gradual boundary.
B21t-- 23 -46 cm - Dark brown (7.SYR 3/3 moist; loam; moderate
medium subangular blocky breaking to granular structure;
friable when moist; few fine iron-manganese oxide bodies;
few fine roots; thin patchy clay films; gradual boundary.
B22t--46 - 114 cm - Brown (7.SYR 4/4) clay loam; common fine
distinct reddish brown (SYR 4/4) mottles; moderate medium
subangular breaking to fine subangular blocky structure;
firm when moist; few fine iron-manganese bodies; few fine
roots; clay films on ped surfaces.
Cr -- 114+ cm.
Stoneburg soils.
262
-------
Location No. 2
Al -- 0 - 23 cm - Dark reddish brown (SYR 3/3) moist; loam; weak
medium subangular blocky breaking to weak medium granular
structure; friable when moist; common medium roots; clear
boundary.
II B21t 23 - 43 cm - Dark reddish brown (2.SYR 3/4) moist
silty clay; moderate coarse subangular breaking to
moderate fine and medium blocky structure; firm when
moist; few fine roots; few iron-manganese oxide bodies;
few clay films; diffuse boundary.
II B22t -- 43 - 106 cm-Dark red (2.SYR 3/6) moist silty clay;
weak coarse blocky breaking to weak fine blocky structure;
firm when moist; few fine roots; few iron-manganese
oxide bodies; ped faces are shiny with clay films.
Cr 106+ cm.
Grainola soils
263
-------
Location No. 3
-- 0 - 10 cm - Dark brown (7.SYR 3/2) moist; loam; moderate
coarse granular structire; friable when moist; common
coarse and medium roots; clear boundary.
-- 10 - 18 cm - Dark brown (7.SYR 3/3) moist; loam moderate
medium subangular blocky breaking to granular structure;
friable when moist; few fine roots; clear boundary.
B21t -- 18 - 37 cm - Dark reddish brown (SYR 3/3) moist; clay loam
(30% clay estimate); weak coarse subangular blocky structure
breaking to fine subangular structure; firm grading to
friable when moist; few fine roots; few fine manganese-
iron oxide bodies; few thin clay films on ped surfaces;
clear boundary.
B3 and Cr 37 - 71 cm - Alternating thin layers of reddish
brown (SYR 4/5) loam, B3 and soft sandstone Cr, ranging
in colors from red to reddish yellow to very pale brown.
Stoneburg soils.
Location No. 4
Al 0 - 19 cm - Brown (7.SYR 4/3) moist; fine sandy loam; weak
fine granular structure; very friable when moist; common
coarse roots; clear boundary.
B2t -- 19 - 45 cm - Reddish brown (SYR 4/4) moist; loam; weak
coarse subangular blocky breaking to granular structure;
friable when moist; few fine and medium roots; thin patchy
clay films; clear boundary.
Cr -- 45 - 80 cm - Soft sandstone ranging in color from pale brown
to brownish yellow; few fine roots.
Darnell-like soils with minimal argillic horizon development.
264
-------
Location No. 5
Al 0 - 10 cm - Dark brown (10YR 3/3) moist; fine sandy loam;
weak fine granular structure; very friable when moist;
common coarse roots; clear boundary.
B2 10 - 27 cm - Brown (7.SYR 4/4) moist; fine sandy loam; weak
coarse subangular blocky breaking to granular structure;
few fine and medium roots; clear boundary.
Cr -- 27 - 32 cm - Light yellowish brown (10YR 6/4) moist soft
sandstone.
Darnell soils.
Location No. 6
Al 0 - 10 cm - Very dark grayish brown (10YR 3/2) moist; fine
sandy loam; weak fine granular structure; very friable when
moist; common coarse and medium roots; clear boundary.
B2 -- 10 - 27 cm - Brown (7.SYR 4/4) moist; fine sandy loam; weak
coarse subangular blocky breaking to granular structure;
few fine and medium roots; clear boundary.
Cr -- 27 - 32 cm - Light yellowish brown (10YR 6/4) moist soft
sandstone.
Darnell soils.
265
-------
Location No. 7
Al -- 0 - 15 cm - Dark brown (7.SYR 3/3) moist; loam; weak medium
subangular breaking to moderate medium granular structure;
friable when moist; common coarse roots; gradual boundary.
B21t 15 - 35 cm - Brown (7.SYR 4/4) moist; clay loam; weak
medium subangular structure; firm when moist; few fine
roots; clay films on ped surfaces; clear boundary.
B22t 35 - 88 cm - Yellowish brown (10YR 5/4) moist; clay loam;
few fine point brown mottles; weak coarse subangular
structure; firm when moist; few fine roots; few fine iron-
manganese oxide bodies; clay films on ped surfaces.
Cr -- 88+ cm.
Soils are gradational between Stoneburg and Grainola soils with
,. less than normal solum thickness.
266
-------
Location No. 8
Al 0 - 14 cm - Dark brown (10YR 3/3) moist; loam; weak medium
subangular breaking to weak medium granular structure;
friable when moist; common coarse roots; clear boundary.
B21t -- 14 - 41 cm - Brown (7.SYR 4/4) clay loam moderate
medium subangular blocky breaking to fine subangular
blocky structure; firm when moist; few fine roots; few
fine iron-manganese oxide bodies; clay films on ped
surface; abrupt boundary.
Cr 41 - 44 cm - Thin layers of yellow and very pale brown
sandy shale; abrupt boundary.
II B22t -- 44 - 62 cm - Light brownish gray (10YR 6/2) moist;
clay loam high in sand; weak coarse subangular blocky
structure; firm when moist; few fine roots; common
coarse bodies of brown (7.SYR 4/4) moist clay loam; clay
films on ped surfaces few fine iron-manganese oxide
concretion.
Cr 62+ cm.
Zaneis-like soils. No mollic epipedon.
267
-------
Location No. 9
Al -- 0 - 18 cm - Dark brown (10YR 3/3) moist; loam; weak medium
subangular breaking to weak medium granular structure;
friable when moist; common medium roots; clear boundary.
B2t -- 18 - 44 cm - Dark yellowish brown (10YR 4/4) moist; clay
loam; weak medium subangular blocky structure; firm
when moist; few fine roots; clay films on ped surfaces;
clear boundary.
-- 44 - 72 cm - Very pale brown (10YR 7/4) moist soft sand-
stone .
Stoneburg-like soils with less than normal thickness.
268
-------
Location No. 10
Al 0 - 21 on - Very dark grayish brown (10YR 3/2) moist;
loam; weak coarse subangular blocky breaking to granular
structure; friable when moist; common coarse roots;
clear boundary.
B21t 21 - 49 cm - Dark reddish brown (SYR 3/4) moist; loam;
weak medium subangular blocky structure breaking to
granular structure; friable when moist; few fine roots;
clay films on ped surfaces; gradual boundary.
B22t -- 49 - 74 cm - Dark reddish brown (SYR 3/4) moist; clay
loam; moderate medium subangular blocky structure; firm
when moist; few fine roots; few fine iron-manganese
oxide bodies; clay films on ped surface; clear boundary.
II B3t 74 - 94 cm - Light brownish gray (10YR 6/2) clay loam;
weak fine blocky structure; firm when moist; few fine
roots; clay films on ped surfaces.
Cr -- 94+ cm.
Stoneburg-like soils.
269
-------
Location No. 11
Al 0 - 15 cm - Dark brown (7.SYR 3/3) moist; loam; weak
medium granular structure; friable when moist; common
medium roots; gradual boundary.
B21 15 - 35 cm - Brown (7.SYR 4/4) moist; loam; weak coarse
subangular blocky breaking to granular structure; friable
when moist; few fine roots; clear boundary.
B22 -- 35 - 52 cm - Dark yellowish brown (10YR 4/4) moist;
loam; weak coarse subangular blocky breaking to granular
structure; friable when moist; few fine roots; clear
boundary.
B3 -- 52 - 70 cm- Coarsely mottled dark grayish brown (10YR
4/2) moist and pale brown (10YR 6/3) moist; loam; weak
coarse subangular blocky structure; friable when moist;
few fine roots.
Cr -- 70+ cm.
Noble-like soils.
Location No. 12
B2
0 - 15 cm - Dark brown (7. SYR 3/3) moist; loam; weak
coarse subangular blocky breaking to moderate fine
granular structure; friable when moist; common medium
roots; clear boundary.
15 - 37 cm - Brown (7. SYR 4/3) moist; loam; weak coarse
subangular blocky breaking to granular structure; friable
when moist; few fine roots.
Cr 37+ cm.
Lucien soils.
270
-------
Location No. 13
Al 0 - 28 - Dark brown (7.SYR 3/3) moist; loam; weak coarse
subangular blocky breaking to moderate fine granular
structure; friable; common medium roots; gradual
boundary.
28 - 45 cm - Dark reddish brown (SYR 3/3) moist; loam;
weak medium subangular blocky breaking to moderate
medium granular studcture; friable when moist; common
medium roots; gradual boundary.
- 45 - 74 cm - Reddish brown (SYR 4/4) loam; weak medium
subangular blocky structure; friable grading to firm
when moist; few fine roots; clay films on ped surfaces;
clear boundary.
B22t 74 - 134 cm -Coarsely mottled reddish brown (SYR 5/3)
(SYR 5/4) moist to pale brown (10YR 6/3) moist; loam;
firm when moist; few fine roots; clay films on ped
surfaces.
Cr 134+ cm.
Stoneburg soils.
271
-------
Location No. 14
r*iis^
^* -^- vT^J- A^*V
Al 0 - 13 cm - Dark brown (7.SYR 3/3) moist; silt loam; weak
medium subangular blocky breaking to weak medium granular
structure; friable when moist; common medium roots; clear
boundary.
Bit 13 - 22 cm - Dark reddish brown (SYR 3/4) moist; silty
clay loam; moderate medium subangular blocky breaking to
fine subangular and angular blocky structure; firm when
moist; common medium roots; clay films on ped surface;
gradual boundary.
B21t -- 22 - 38 cm Dark reddish brown (2.SYR 3/4) moist; silty
clay; weak coarse blocky breaking to fine blocky structure;
firm when moist; few fine roots; few fine iron-manganese
oxide bodies; clay films on ped surfaces; diffuse boundary.
B22t -- 38 - 65 cm - Dark reddish brown (2.SYR 3/4) moist; silty
clay; weak coarse blocky breaking to fine blocky structure;
very firm when moist; few fine roots; estimated 3 percent
calcium carbonate bodies; ped surfaces are shiny; diffuse
boundary.
B231 65 - 119 cm - Dark reddish brown (2.SYR 3/4) moist;
silty clay; weak coarse blocky breaking to fine blocky
structure; very firm when moist; non-intersecting slick-
ensides; few fine roots; shiny ped surfaces.
Cr -- 119+ cm.
Aydelotte soils.
272
-------
Location No. 15
A-l -- 0 - 12 cm - Reddish brown (SYR 4/4) moist; loam; weak
coarse subangular breaking to weak fine granular structure;
friable when moist; common medium roots; clear boundary.
B2t 12 26 cm - Reddish brown (SYR 3.5/4) moist; loam; weak
medium subangular blocky structure; friable when moist;
few fine roots; clay films on ped surfaces; clear boundary.
B3 26 - 39 cm - Brown (7.SYR 4/3) moist loam; weak coarse
subangular blocky breaking to granular structure; friable
when moist; few fine roots; few fragments of soft sand-
stone clear boundary.
Cr 39 - 52 cm - Light gray (10YR 7/1) moist, soft sandstone.
These soils are gradational in development between Lucien and
Stoneburg.
Location No. 16
Al -- 0 - 22 cm - Dark reddish brown (SYR 3/3) moist; loam;
weak fine granular structure; common medium roots;
gradual boundary.
B2 22-50 cm - Reddish brown (SYR 4/4) moist; loam; weak
coarse subangular breaking to granular structure; friable
when moist; common medium roots; abrupt boundary.
Cr -- 50 - 58 cm - Very pale brown (10YR 7/3) moist soft
sandstone.
Lucien soils.
273
-------
Location No. 17
Al 0 - 14 cm - Dark brown (10YR 3/3) moist; loam; weak
medium subangular blocky breaking to granular structure;
friable when moist; common medium roots; gradual boundary.
B21t 14 - 35 cm - Yellowish brown (10YR 5/4) moist; clay loam;
moderate medium subangular blocky breaking to fine
subangular blocky structure; few fine and medium roots;
clay films on ped surfaces; clear boundary.
B22t -- 35 - 93 cm - Alternating layers of yellow, brown and
gray clay and clay loam that average light yellowish
brown (10YR 5/4) moist clay; weak medium blocky breaking
to fine blocky structure; firm when moist; few fine roots;
few thin layers of weathered shale; clay films on ped
surfaces; clear boundary.
Cr 93 - 114 cm - Dark reddish brown (2.SYR 4/4) moist; shale
with few seams of gypsum.
Grainola-like soils.
274
-------
Location No. 18
Al -- 0-15 cm - Dark reddish brown (SYR 3/3) moist; loam; weak
medium subangular blocky breaking to moderate medium
granular structure; friable when moist; common medium
roots; gradual boundary.
B2 15 28 cm - Reddish brown (SYR 4/3) moist; clay loam;
moderate medium subangular blocky structure; moist firm
grading to friable; few fine roots; clear boundary.
B3 -- 28 - 75 - Reddish brown (SYR 4/3) moist; clay loam; weak
medium subangular blocky breaking to fine subangular
blocky structure; firm when moist; common bodies of soft
sandstone.
Cr 75+ on.
Gradational soils between Lucien and Grainola.
275
-------
XvXvX*
Location No. 19
Al -- 0 - 17 cm - Dark reddish brown (SYR 3/3) moist; loam;
weak medium subangular blocky breaking to moderate
granular structure; friable when moist; common medium
roots; gradual boundary.
B21t -- 17 - 38 cm - Dark reddish brown (SYR 3/4) moist; clay
loam; moderate medium subangular blocky breaking to fine
subangular structure; firm when moist grading to friable;
common medium and fine roots; clay films on ped surfaces;
clear boundary.
B22t 38 - 96 cm - Reddish brown (2.SYR 4/4) moist; silty clay;
weak medium blocky breaking to fine blocky structure;
very fine when moist; few fine roots mostly on ped
surfaces; few fine iron-manganese oxide bodies; clay
films on ped surfaces.
Cr 96+ cm.
Grainola soils.
276
-------
I
Location No. 20
Al 0 - 22 cm - Dark brown (10YR 3/3) moist; loam; weak medium
granular structure; friable when moist; few fine roots;
gradual boundary.
B21t -- 22 - 52 cm - Brown (7.SYR 4/3) moist; clay loam; weak
medium subangular blocky structure; firm when moist; few
fine roots; clay films on ped surfaces; clear boundary.
B22t -- 52 - 84 cm - Brown (7.SYR 5/4) moist; clay loam; weak
coarse blocky breaking to medium blocky structure few
fine roots; few fine iron-manganese bodies; clay films
on ped surfaces; clear boundary.
Cr 84 - 102 cm - Alternating thin layers of very pale brown
(10YR 7/3) soft sandstone and light brownish gray
(10YR 6/2) shale.
Stoneburg-like soils.
277
-------
Location No. 21
Al 0 - 14 cm - Dark brown (7.SYR 3/2) moist; silt loam; weak
medium subangular blocky breaking to granular structure;
friable when moist; common medium roots; gradual boundary.
Bit -- 14 - 28 cm - Dark brown (SYR 3/3) moist; silty clay loam;
moderate medium subangular blocky breaking to fine
subangular blocky structure; friable grading to firm
when moist; common medium roots; clay films on ped
surface; clear boundary.
B21t 28 - 63 cm - Dark reddish brown (SYR 3/4) moist; silty
clay; moderate medium blocky breaking to fine blocky
structure; firm when moist; few fine roots; clay films
on ped surfaces; the lower 10 cm has streaks of olive
colored clays; clear boundary.
B22t --63 - 150 cm - Dark reddish brown (2.SYR 3/4) moist;
silty clay; weak coarse blocky breaking to fine blocky
structure; very firm when moist; few fine roots; mostly
on ped surfaces; few fine iron-manganese oxides
concretions; few non-intersecting slickensides; clay
films on ped surfaces.
Cr 150+ cm.
Renfrew soils.
278
-------
Location No. 22
Al 0 - 11 cm - Dark brown (7.SYR 3/3) moist; loam; weak
medium granular structure; friable when moist; common
medium roots; gradual boundary.
B2t 11 - 54 cm - Dark reddish brown (2.SYR 3/4) moist; clay
loam; moderate medium subangular blocky breaking to fine
subangular blocky structure; firm when moist; few fine
roots; clay films on ped surface; clear boundary.
B3 -- 54 - 70 cm - Brown (7.SYR 4/2) moist; clay loam; with
common coarse distinct light brownish gray (10YR 6/2)
moist mottles; weak coarse subangular blocky structure;
firm when moist; few fine roots; clay films on ped
surfaces; clear boundary.
Cr 70 - 82 cm - Light gray (10YR 7/2) moist soft sandstone.
Stoneburg-like soils.
279
-------
Location No. 23
Al -- 0 - 19 on - Dark brown (7.SYR 3/3) moist; silt loam; weak
medium subangular block/ breaking to weak medium granular
structure; friable when moist; common coarse and medium
roots; gradual boundary.
Bit -- 19 - 38 cm - .Dark reddish brown (SYR 3/3) moist; silty
clay loam; moderate medium subangular blocky breaking
to fine subangular blocky structure; firm grading to
friable when moist; common coarse and medium roots; clay
films on ped surfaces; clear boundary.
B21t 38 - 72 cm - Dark reddish brown (2.SYR 3/4) moist;
silty clay; moderate medium subangular blocky breaking
to fine blocky structure; firm when moist; few fine roots;
few fine iron-manganese oxide bodies; clay films on
ped surfaces; gradual boundary.
B22t 72 - 116 cm - Dark Teddish brown (2.SYR 3/4) moist;
silty clay; weak coarse blocky breaking to fine blocky
structure; very firm when moist; few fine roots; few fine
calcium carbonate bodies; few non-intersecting slicken-
sides; clay films on ped surfaces; clear boundary.
Cr -- 116 - 121 cm - Light gray (10YR 6/1) weathered shale with
bits of sandstone and silty clay.
Renfrew-like soils with less than normal solum thickness.
280
-------
Location No. 24
Al 0 - 15 cm - Dark reddish brown (SYR 3/2) loam; weak medium
subangular blocky breaking to weak medium granular
structure; friable when moist; common coarse and medium
roots; clear boundary.
Bit 15 - 35 cm - Dark reddish brown (SYR 3/3) moist; clay loam;
moderate medium subangular blocky breaking to fine
subangular blocky structure; firm grading to friable when
moist; few fine and medium roots; clay films on ped
surfaces; gradual boundary.
B2t 38 - 58 cm - Dark reddish brown (SYR 3/3) moist silty clay;
moderate medium subangular blocky breaking to fine blocky
structure; firm when moist; few fine medium roots; few
fine iron-maganese oxide bodies; clay films on ped
surfaces; clear boundary.
Cr 58 - 76 cm - Thin layers of very pale brown (10YR 7/3)
soft sandstone and light gray (10YR 7/2) shale.
Grainola-like soil with mollic epipedon.
Location No. 25
Al -- 0 - 18 cm - Dark brown (7.SYR 3/3) moist; loam; moderate
medium granular structure; friable when moist; common
coarse and medium roots; gradual boundary.
B21t 18 - 34 cm - Dark reddish brown (SYR 3/3) moist; clay
loam; weak medium subangular blocky breaking to fine
subangular blocky structure; firm when moist; common
medium roots; clay films on ped surfaces; gradual
boundary.
B22t 34 - 54 cm - Reddish brown (SYR 5/3) moist clay loam;
moderate fine subangular blocky structure; firm when
moist; few fine roots; clay films on ped surfaces;
clear boundary.
Cr 54 - 60 cm - Brown (7.SYR 5/4) moist soft sandstone.
Stoneburg soils.
281
-------
Location No. 26
Al 0 - 14 cm - Dark brown (7.SYR 3/3) moist; clay loam;
weak medium subangular block/ breaking to moderate
medium granular structure; friable grading to firm
when moist; common medium roots; gradual boundary.
B2t 14 - 32 cm - Reddish brown (SYR 4/3) moist; clay loam;
moderate very fine and fine subangular blocky structure;
firm when moist; few fine roots; clay films on ped
surfaces; clear boundary.
Cr 32 - 60 cm - Thin layers reddish brown highly weathered
shale; with few seams of light olive brown shale and
sandstone; shales texture to clay loam; few fine roots.
Gradational soil development. Grainola-like soils.
Location No. 27
Al 0 - 17 cm - Dark reddish brown (SYR 3/3) moist; loam;
weak medium subangular blocky breaking to weak medium
granular structure; friable when moist; common medium
roots; gradual boundary.
B2t 17 - 50 cm - Dark reddish brown (SYR 3/4) moist; clay loam;
moderate fine subangular blocky structure; firm grading
to friable when moist; common medium and fine roots; clay
films on ped surfaces; clear boundary.
B3 50 - 81 cm - Reddish brown (SYR 4/4) clay loam; weak fine
subangular blocky structure; firm when moist; few fine.
roots; common fragments of sandstone.
Cr 81+ cm.
Stoneburg-like soils.
282
-------
Location No. 28
Al -- 0 - 21 cm - Dark Brown (7.SYR 3/3) moist; loam; weak
medium subangular blocky breaking to moderate fine granular
structure; friable when moist; common medium roots;
gradual boundary.
B2 21 - 47 cm - Brown (7.SYR 4/4) moist; loam; weak medium
subangular blocky structure breaking to granular structure;
friable when moist; few fine and medium roots; clear
boundary.
Cr 47 - 56 cm - Olive-yellow (2.SYR 6/6) soft sandstone.
Lucien soils.
Location No. 29
Al -- 0 - 12 cm - Dark brown (7.SYR 3/3) moist; fine sandy loam;
weak fine granular structure; very friable when moist;
common medium roots; gradual boundary.
B2 12 - 26 cm - Brown (7.SYR 4/3) moist; fine sandy loam;
weak fine granular structure; very friable when moist;
few fine roots; clear boundary.
Cr -- 26 - 32 cm - Yellowish brown (10YR 5/4) soft sandstone.
Lucien soils.
283
-------
APPENDIX H
AVERAGE (21 SAMPLING DATES) SOIL WATER CONTENT (%,X±SE)
FOR SAMPLING LOCATIONS
Locotion No. 4
Soil Water (%)
nO;/ 12 14 16 113 20 22
\jr"~~~\ I i i i i i
20
S30
40-
Locotion No. 5
Soil Water (%)
»0.. 8 10 12
I10
£20
flj
o30
Locotion No. 6
Soil Water (%)
*
8 10 12
E
o
10
li.20
a>
°30
Locotion No. 7
Soil Water (%)
10 12 14 16 18 20
10
20
130
40
Locotion No. 12
Soil Water (%)
. 8 10 12
10
30
Locotion No. 29
Soil Water (%)
Q0 8JO_I2_
Figure H-l. Soil profiles with depths of 40 cm or less.
284
-------
~ I0
§20
£ 30
ca.
S 40
50
Location No. 3
Soil Water (%)
8 10 12 14 16 18 20 22
Location No. 11
Soil Water (%)
8 10 12 14 16 18 20 22
Location No. 15
Soil Water (%)
8 10 12 14 16 18 20 22
_ 10
1 20
f 30-
I 40
50
..
"
Figure H-2. Soil profiles with depths of 50 cm.
285
-------
Locotion No. 16
Location No. 23
rf
u
10
.§30
r /trt
C_HU
°50
cn
ou
70
in
IU
oo
^? tU
o
~30
1 40
50
cn
bU
70
Soil Water (%)
).. 12 14 16 18 20 22 24 26 «(
" i i i i i i l i U
- «-<- 10
g»
^_- _j g-^u
Cj
. 1 50
H ______ cn
ou
- . 70
Location No. 19
Soil Water (%)
3 12 14 16 18 20 22 24 26 A
r" 1 i 1 1 i i i l U
h. , , in
, i . ~ on
^
-4-I 50
fin
70
Soil Water (%)
) . 10 12 14 16 18 20 22
* i i i i i ' i
; ~t
t I-H
-
H-4
Location No. 28
Soil Water (%)
),, 10 12 14 16 18 20 22
f i i i i i i i
J ,
A-l
- ^
. --
Figure H-3. Soil profiles with depths of of 70 cm.
286
-------
Locotion No. I
Location No. 2
0(
u
10
20
30
I40
£50
a.
a>
O cn
bU
70
ftn
ou
90
10
20
_30
§40
f»
Sr,n
a t)U
70
oo
80
90
Soil Water (%)
).. 12 14 16 18 20 22 j:
" i i i I 1 i U
- 10
| 20
p 30
iU ^40
H- £50
o.
. -, ^Pcn
o 60
H- 70
. Of)
OU
90
Location No. 2
Soil Water (%)
L 14 16 18 20 22 24 n(
"i ll l 1 U
- i 10
*-4 20
f- 30
--[- 140
"o.
|2? Rft
*-- 70
on
J ou
> -i Qf\
-^ 5jy
Soil Water (%)
) 10 12 14 16 18 20 22 24 26
" i i i i > T" "T T
. ,
-
t- -«
f
- » <
> «
Location No. 13
Soil Water (%)
.. 12 14 16 18 20 22 24 26 28
* i i i ii i i i i
:t
ZL-
, ,
,
,
Figure H-4. Soil profiles with depths of 90 cm.
287
-------
Location No. 10 Location No. 14
Soil Water (%) Soil Water (%)
rf
10
20
30
^40
o
_c ou
f60
70
80
90
100
110
0C
10
20
30
"i40
0
j- 50
£60
o
70
80
90
100
110
) 12 14 16 18 20 22 nO_ 12 14 16 18 20 22 24 26 28
- - 10
[ ' 20
-}- 30
4- -^40
i ^i
|eo
»--< 70
on
90
inn
IUU
-« HO
Location No. 20
4<
, 1 ,
1
Location No. 22
Soil Water (%) Soil Water (%)
) 10 12 14 16 18 20 nO- 12 14 16 18 20 22 24 26
" i " i i i r u
- --. 10
^_ 20
>-- 30
V ^MBT^^ ^"^ AC
L-. QJ
i 1 ~ 50
°- fin
o
i 1 70
rl 80
1 , gr
100
110
' i ' i i i i i
., ,
t i
J
l~ll
p
""i
L
*--
,-->
i H
Figure H-5. Soil profiles with depths of 110 cm.
288
-------
APPENDIX I
TABLE 1-1. SAMPLING DATE, PRECIPITATION INSOAK, SOIL WATER CONTENT CHANGE AND SOIL WATER USE RATE
PER PERIOD
Dayl±/
6194/
:N=7 y
6220
;N=29
.6235
: N=29
ro i 6262
eg | N=29
6296
N=29
6325
N=29
6360
N=29
;7020
N=29
7090
N=29
7112
N=29
7130
N=7
^^
6220
6235
6262
6296
6325
6360
7020
7090
7112
7130
7148
Oays
26
15
27
34
29
35
25
70
22
18
18
Ppt.3/
Insoak
(mm)
39
9
52
71
52
50
37
20
24
-
8
50
Soil Profile Sections (cm)
0-15
_1696/
*-*
-1.9
*
2.0
*
-3.0
*
4.8
*
-3.4
*
7.7
*
-0.1
0.87
3.4
*
-3.0
*
13.0
*
15-25
-14.3
*
-4.8
*
3.3
*
-5.3
5.1
*
0.8
0.32
5.7
*
-0.6
0.20
3.9
*
-0.9
0.08
9.1
*
25-35
-8.7
*
-6.1
*
1.6
*
-4.6
*
3.1
*
2.1
*
2.0
*
-0.1
0.79
3.3
*
0.4
0.12
6.3
*
35-45
-6.0
*
-5.9
*
-0:6
0.37
-3.9
*
2.1
*
1.5
*
0.8
*
0.5
*
1.9
*
1.0
*
5.4
*
45-60
-3.3
0.06
-7.1
*
-4.7
*
-4.4
*
1.3
0.10
1.7
*
0.8
*
0.9
*
2.3
*
1.1
*
1.7
0.13
60-80
-1.0
0.70
-4.5
*
-8.9
*
-5.5
*
-0.1
0.93
0.4
0.58
0.0
1.0
0.7
0.14
1.1
0.22
0.1
0.84
0.5
0.50
80-100
-JJ
0.0
1.0
-6.7
*
-7.0
*
1.9
0.62
-1.9
0.58
0.2
0.62
0.4
0.31
-0.7
0.11
1.1
*
0.5
0.50
100-120
-1.0
0.51
-2.5
0.34
-5.5
*
-2.3
*
1.7
0.34
-0.7
0.39
0.5
0.39
1.3
0.39
-1.0
0.42
~
Total
Soil
Water
(mm)
-50.4
*
-23.2
*
-4.8
0.22
-24.0
*
16.9
*
1.7
0.55
16.2
*
0.9
0.54
14.0
*
-1.7
0.15
32.4
*
Soil Water -1
Use Rate
(mm/day)
3.44
*
2.15
*
2.10
*
2.79
*
1.21
*
1.38
*
0.83
*
0.27
*
0.45
*
0.54
*
0.98
*
(Continued)
-------
TABLE 1-1. (Continued)
Dayl-'
7148
N=7
7154
N=7
7163
N=7
7176
N=7
7185
N=7
7190
N=5
7206
N=6
7214
N=6
7221
7226
N=6
7232
M=6
7255
N-6
Day2^
7154
7163
7176
7185
7190
7206
7214
7221
7226
7232
7255
7263
Days
6
9
13
9
5
16
8
7
5
6
23
8
Ppt.l'
Insoak
(mm)
0
5
46
7
28
134
31
1
0
6
74
4
Soil" Profile Sections (cm)
0-15
-9.6
*
-6.7
*
10.4
*
-10.3
*
4.3
*
14.0
*
-4.8
0.16
-4.8
0.29
-12.8
*
-0.2
0.87
2.8
-0.3
15-25
-5.7
*
-5.3
*
7.0
*
-6.1
*
2.6
*
9.6
t
-3.2
*
-6.8
*
-9.7
*
-2.2
*
0.3
0.53
-0.5
25-35
-2.7
*
-1.8
*
3.3
*
-2.8
*
0.3
0.75
9.0
*
-2.2
*
-5.3
*
-6.5
*
-2.8
*
-1.5
0.08
-0.8
35-45
0.4
0.59
-1.0
0.08
1.2
0.28
-0.8
0.10
-0.6
0.59
6.3
*
-1.4
*
-2.5
0.29
-5.0
-3.2
*
-2.0
0.21
-0.8
45-60
2.0
0.32
1.3
*
1.7
0.44
1.0
0.23
-1.0
0.61
10.3
0.14
-1.5
0.32
3.0
0.37
-3.0
0.66
-3.7
0.07
-4.0
0.30
-2.5 .
60-80
0.5
0.80
1.0
0.50
3.0
0.59
1.0
-1.0
0.76
10.0
0.43
-2.0
3.5
0.39
-4.0
0.63
1.0
0.80
-7.0
0.54
-3.0
80-100
0.0
1.0
0.5
0.50
2.0
0.63
2.0
0.30
-0.3
0.91
-0.5
0.50
-0.5
0.50
3.0
0.50
-2.0
0.76
3.0
0.50
-4.5
0.32
-1.0
Total
Soil
Water
100-120 (mm)
-16.3
*
-13.3
*
23.3
*
-18.1
* *
6.1
0.30
47.4
. *
-13.5
*
-32.8
*
-24.2
*
-8.0
0.07
-7.5
0.42
-5.5
Soil Water -1
Use Rate
(mm/day)
2.72
*
2.03
*
1.75
*
2.78
*
4.38
5.41
*
5.56
*
4.83
*
4.84
*
2.33
0.59
3.54
*
1.19
(Continued)
-------
TABLE 1-1. (Continued)
Dayl-i'
7263
N=6
7268
N=6
7288
N=6
7298
N=6
7303
H=6
7317
N=6
7325
N=6
7333
N=6
7338
N=6
7352
N=6
8010
N=6
8022
H=6
Da 2^
7268
7288
7298
7303
7317
7325
7333
7338
7352
8010
8022
8043
Days
5
20
10
5
14
8
8
5
14
23
12
21
Ppt.l/
Insoak
(nm)
13
31
39
12
41
9
7
0
1
76
0
5
Soil Profile Sections (cm)
0-15
0.0
3.3
*
-2.3
*
0.8
*
3.0
*
-2.2
*
-2.2
*
-0.2
0.36
-0.3
0.17
13.0
*
-6.2
*
-1.2
*
15-25
0.0
2.7
*
-1.5
*
0.2
0.74
1.7
*
0.2
0.61
-2.5
*
-0.3
0.17
-0.7
*
16.8
*
-5.2
*
-1.8
*
25-35
0.0
0.8
0.09
0.0
1.0
-0.7
0.10
1.2
*
0.2
0.61
-1.0
0.08
0.2
0.36
-0.8
*
9.7
-0.7
0.44
-0.7
0.17
35-45
-0.4
0.48
0.4
0.59
0.0
1.0
-0.2
0.62
0.6
0.21
-0.4
0.18
-0.2
0.62
0.2
0.37
-0.6
0.07
2.6
*
1.8
*
0.2
0.37
45-60
0.3
0.64
-0.7
0.39
-0.7
0.39
0.5
0.18
1.0
0.25
-0.7
0.39
0.3
0.64
0.5
0.18
-1.5
*
2.0
*
0.5
0.50
2.0
0.39
60-80
0.0
1.0
-2.5
0.13
-1.0
0.50
1.5
0.50
0.5
0.50
-2.0
0.30
1.0
0.70
1.0
-2.0
0.30
2.0
0.30
0.5
0.50
-1.5
0.20
80-100
0.0
1.0
-1.0
0.50
-2.0
0.30
1.5
0.20
0.0
1.0
-1.5
0.20
2.0
0.0
1.0
-1.5
0.20
2.5
0.34
-0.5
0.50
-1.5
0.20
Total
Soil
Water
100-120 (nut)
-0.2
0.81
5.0
0.08
-5.3
*
1.7
0.43
7.2
*
-4.3
0.07
-4.2
0.14
0.33
0.70
-4.7
- *
44.5
*
-10.2
*
-3.5
0.23
Soil Water -f
Use Rate
(mm/day)
2.63
*
1.30
4.43
2.06
2.4
*
1.66
1.40
*
-0.07
0.70
0.40
*
1.37
0.85
*
0.40
*
(Continued)
-------
TABLE 1-1. (Continued)
Ppt.-' Soil Profile Sections (cm)
Dayl-i/
8043
8060
N=6
8115
N=6
8120
N=6
1
:8143
N=6
ro i
vo 8147
M N=6
8157
N=6
8220
N=6
8235
N=6
8268
N=29
8337
N=6
8352
N=6
Day2-X
8060
8115
8120
8143
8147
8157
8220
8235
8268
8337
8352
9021
Days
17
55
5
23
4
10
63
15
33
69
15
34
Insoak
(mm)
2
20
3
87
11
0
198
54
37
90
52
89
0-15
-1.7
*
20.3
*
-3.5
0.12
-10.5
*
5.3
*
-5.2
*
14.3
*
-5.8
*
-13.3
*
-3.0
*
8.3
*
17.2
*
15-25
-1.2
*
11.5
ft
1.33
0.35
-6.8
«
4.8
*
-4.5
*
3.7
ft
-4.3
*
-10.3
*
-2.9
*
7.0
*
9.8
*
25-35
-0.5
0.42
8.2
*
1.0
0.30
-3.7
0.09
2.8
*
-0.7
.73
2.7
0.15
-5.0
*
-11.5
*
-0.3
0.31
6.5
*
8.5
«
35-45
0.2
0.70
7.6
*
1.0
0.46
-1.4
0.53
2.2
0.07
3.8
0.17
-3.2
0.26
-4.8
*
-10.2
*
0.3
0.20
4.0
0.08
7.2
*
45-60
-1.0
0.67
10.3
0.13
0.3
0.84
-0.3
0.93
3.0
0.10
4.7
0.19
-2.0
0.61
-6.3
0.06
-13.5
*
0.3
0.38
2.75
0.14
8.0
0.14
60-80
1.5
0.74
0
1.0
-1.5
0.20
3.5
0.09
-2.0
0.30
7.5
0.28
-2.5
0.50
-1.5
0.20
-5.0
ft
-2.1
*
2.0
0.30
-0.5
0;79
80-100
4.0
0.63
-4.5
0.56
-0.5
0.50
1.5
0.50
-0.5
0.50
8.5
0.37
-5.5
0.36
0.5
0.50
-2.5
0.34
-5.4
*
1.5
0.20
0.0
-
Total
Soil
Uater
100-120 (mm)
-1.0
0.85
50.7
*
-1.2
0.81
-19.8
0.06
15.8
*
2.3
0.71
13.2
*
-23.7
*
-55.3
*
-5.5 -8.97
0.09 *
28.3
*
46.5
*
Soil Water ^
Use Rate
(mm/day)
0.18
0.58
-0.56
*
0.83
0.40
4.78
*
-1.21
0.20
-0.23
0.71
2.93
*
5.18
*
2.80
*
1.43
*
1.58
*
1.25
*
(Continued)
-------
ro
U3
CO
TABLE 1-1. (Continued)
Dayl^
9021
N=29
Day2^/ Days
9049 28
Ppt.-?/
Insoak
(mm) 0-15
8 -15.2
*
Soil Profile Sections (cm)
15-25 25-35 35-45 45-60
-2.5 -2.7 -1.4 -0.7
* * * 0.23
60-80
2.7
0.17
80-100 100-120
-2.4 -1.0
* 0.09
Total
Soil
Water
(rnn)
-22.9
*
Soil Water -1
Use Rate
(mm/day)
0.24
*
2/Day 1 - Proceeding sampling date.
/Day 2 - Next succeeding sampling date.
/Precipitation Insoak - (Precipitation-Runoff).
'Soil Hater Use Rate = (Ppt. Insoak-[Tota1 Soil Water on Day 1 - Total Soil Water on Day 2])/Days.
-/When N 29. difference In Total Soil Water Calculated by regression equations.
implant Year Date (e.g., 6_ _ = 1976; _194=194 days after 1 November (1 Nov: = 1, 31 Oct. = 365).
"^Difference in soil water (Bay 1-Day 2) for that soil profile section.
o/No soil water reading at this depth on one or both dates.
a/Number of location sampled.
3/Probability level; * = P 0.05.
-------
APPENDIX J
AVERAGE (N=25) PLANT BIOMASS (X±SE; KG/HA, OVEN-DRY) COMPONENTS ON A
TALLGRASS PRAIRIE WATERSHED GRAZED BY CATTLE IN
NORTH CENTRAL OKLAHOMA, 1976-78
Date!/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7180
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
Live
X
310
630
1300
1420
950
1160
960?/
£/
_
_
_
_
-
460
910
1440
1250
1060
1310
_
_
.
_
15
420
900
1500
1630
1630
1020
850
SE
40
30
140
110
85
105
115
_
_
_
_
_
-
25
40
90
85
125
170
_
_
_
_
1
35
65
110
160
125
115
115
Standing
Dead
X
1570
1250
1330
1280
1320
1260
1400
2340
2310
1530
1890
1320
1420
1100
840
730
650
960
860
1750
1520
1410
1630
1000
880
950
1030
1070
1150
1170
1420
SE
290
230
190
190
170
160
210
270
290
250
250
290
250
190
160
120
70
140
100
160
200
180
270
13,0
170
170
100
100
100
160
150
Standing
Live + Dead
I .
1870
1880
2630
2700
2280
2420
2370
2340
2310
1530
1890
1320
1420
1560
1750
2170
1890
2030
2170
1750
1520
1410
1630
1020
1300
1860
2530
2700
2780
2190
2270
SE
310
240
240
270
230
240
270
270
290
250
250
290
250
190
180
180
130
240
240
160
200
180
270
130
180
190
140
220
200
240
230
Ground
Litter
I
1440
2200
2480
2980
2920
2860
3540
1970
2710
2560
2210
2020
1430
1760
2100
1380
1040
1430
2210
1920
4420
2100
2740
1540
1090
2400
1920
1480
1480
1900
2460
SE
220
320
400
720
410
440
950
330
450
400
210
410
170
250
520
280
160
170
520
410
1960
360
440
210
230
490
370
310
290
410
390
YyPlant year date; 6=1976, 6163 = 163 days after 1 November 1975.
Live vegetation not separated from standing dead.
294
-------
APPENDIX K
LIST OF PLANT SPECIES FOUND ON TALL6RASS PRAIRIE WATERSHED GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
ro
Family
Genus
Species
Common
Code
CDACCCC
Gramlneae
Gramineae
Gramlneae
Gramlneae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Aegilops
Agropyron
Agrostis
Andropogon
Andropogon
Andropogon
Brothriochloa
Brothriochloa
Bouteloua
Bouteloua
Bouteloua
Bromus
Bromus
Bromus
Buchloe
Chloris
Cynodon
Digitaria
Elymus
Elymus
Eragrostis
Eragrostis
Eragrostis
Eriochloa
Hordeum
cylindrica Goatgrass
smithii
spp.
gerardi
ternarius
virginicus
saccharoides
spp.
curtipendula
gracilis
hirsuta
japonicus
tech to rum
uniolodes
dactyl oides
verticillata
dactyl on
spp.
canadensis
virginicus
cilianensis
spectabilis
spp.
gracilis
pusillum
Western Wheatgrass
Agrostis
Big Bluestem
Slitbeard Bluestem
Broomsedge Bluestem
Silver Bluestem
Oldworld Bluestem
Sideoats Grama
Blue Grama
Hairy Grama
Japanese Brome
Cheatgrass
Buffalograss
Tumble Windmill grass
Bermudagrass
Crabgrass
Canada Wildrye
Virginia wildrye
Stinkgrass
Purple Lovegrass
Lovegrass
Southwestern Cupgrass
Little Barley
AECY
AGSM
AGR
ANGE
ANTE2
ANVI2
BOSA
BOTHR
BOCU
BOGR2
BOH 1 2
BRJA
BRTE
BRUN
BUDA
CHVE2
CYDA
DIGI2
ELCA4
ELVI3
ERCI
ERSP
ERAGR
ERGR4
HOPU
(Continued)
-------
APPENDIX K (Continued)
ro
10
Family
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Gramineae
Acanthaceae
Apocynaceae
Asclepiadaceae
Boraginaceae
Campanulaceae
Caryophyllaceae
Caryophyllaceae
Commelinaceae
Commelinaceae
Compsitae
Compos itae
Genus
Leptol oma
Manisuris
Muhlenbergia
Panicum
Panicum
Pan 1 cum
Paspalum
Poa
Schedonnardus
Schizachyrium
Setaria
Sorghastrum
Sporobolus
Tridens
Tridens
Vulpia
Ruellia
Apocynum
Asclepias
Lithospermum
Triodanis
Spergularia
Stellaria
Aneilema
Tradescantia
Achillea
Ambrosia
Species
cognatum
cylindrica
spp.
scribnerianum
spp.
virgatum
spp.
spp.
paniculatus
scoparium
spp.
nutans
spp.
flavus
spp.
oc to folia
FflRR<\
ciliosa
spp.
spp.
spp.
spp.
echinosperma
media
spp.
ohiensis
lanulosa
psilostachya
Common
Fall Witchgrass
Carolina Jointtail
Muhly
Scribners Panicum
Panicum
Switchgrass
Paspalum
Bluegrass
Tumblegrass
Little Bluestem
Bristlegrass
Indiangrass
Dropseed
Purpletop
Tridens
Six-Weeks Fescue
Fringeleaf Ruellia
Dogbane
Milkweed
Gromwel 1
Venus' Looking Glass
Sandspurry
Starwort Chickweed
Spiderwort
Western Yarrow
Western Ragweed
Code
LECO
MACY
MUHLE
PASC5
PANIC
PAVI2
PASgJ
POA
SCPA
SCSC
SETAR
SONU2
SPORO
TRFL2
TRIDE
VUOC
RUAC
APOCY
ASCLE
LITHO
TRIOD
SPEC
STME2
ANEIL
TROH
ACLA
AMPS
(Continued)
-------
APPENDIX K (Continued)
ro ,
Family
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Compos itae
Cruci ferae
Cruci ferae
Cruci ferae
Cruci ferae
Genus
Antennaria
Artemisia
Chrysopsis
Cirsium
Echinaceae
Erigeron
Erigeron
Erigeron
Eupatorium
Eu pa tori urn
Gaillardia
Gaillardia
Gnaphalium
Grindelia
Hieracium
Hymenopappus
Kuhnia
Lactuca
Liatris
Ratibida
Rudbeckia
Rudbeckia
Sol idago
Taraxacum
Vernonia
Xanthocephalum
Barbarea
Capsella
Lepidium
Lepidium
Species
neglecta
ludoviciana
pilosa
spp.
angusti folia
canadensis
ramosus
strigosus
rugosum
spp.
fastigiata
spp.
spp.
squarrosa
longipilum
spp.
eupatoroides
canadensis
punctata
columnaris
nitida
hirta
spp.
officinale
baldwini
dracunculoides
verna
bursa-pastoris
densiflorum
spp.
Common
Pussy toes
Louisiana Sagewort
Soft Goldaster
Thistle
Blacksamson
Horseweed Fleabane
Daisy Fleabane
Rough Fleabane
White Snakeroot
Eupatorium
Prairie Gaillardia
Gaillardia
Cudweed
Curlycup Gumweed
Longbeard Hawk weed
Wooly White
False Boneset
Canada Lettuce
Dotted Gayfeather
Upright Prairiecone
Shiny Conef lower
Blackeyedsusan
Gol denrod
Dandelion
Western Ironweed
Common Broomweed
Early Wintercress
Common Shepherds Purse
Prairie Pepperweed
Pepperweed
Code
ANNE
ARLU
CHPI2
CIRSI
EC AN 2
ERCA5
ERRA
ERST3
EURU
EUPAT
GALAF
GAILL
GNAPH
GRSQ
HIL02
HYME4
KUEU
LACA
LIPU
RATIB
RUN 1 3
RUHI2
SOLID
TAOF
VEBA
XADR
BAVE
CABU2
LEDE
LEPID
(Continued)
-------
APPENDIX K (Continued)
ro
10
00
Family
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Gentianacee
Geraniaceae
Iridaceae
Labiatae
Labiatae
Labiatae
Labiatae
Labiatae
Labiatae
Labiatae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Leguminosae
Liliaceae
Linaceae
Linaceae
Genus
Croton
Euphorbia
Tragia
Sabatia
Geranium
Sisyrinchium
Hedeoma
Labiatae
Lamium
Marrubium
Monarda
Monarda
Salvia
Acacia
Amorpha
Cassia
Desmodium
Krameria
Lespedeza
Lespedeza
Neptunia
Oxytropis
Petal ostemon
Psoralea
Schrankia
Astragalus
Baptisia
Allium
Linum
Linum
Species
texensis
marginata
urtici folia
campestris
spp.
spp.
spp.
spp.
spp.
spp.
- pectinata
spp.
pitcheri
angustissima
canescens
fasciculata
sessili folium
spp.
spp.
virginica
lutea
spp.
candidum
tenui flora
uncinata
caryocarpus
spp.
spp.
rigidum
spp.
Common
Texas Croton
Snow on the Mountain
Nettle-Leaf Noseburn
Prairie Rosegentian
Geranium
Blueeye-Grass
Pennyroyal
Mint
Henbit
Horehound
Plains Beebalm
Beebalm
Pitchers Sage
Prairie Acacia
Leadplant
Showy Partridgepea
Sessile Tickclover
Ratany
Lespedeza
Slender Lespedeza
Yellow Neptunia
Crazyweed
White Prairieclover
Wild Alfalfa
Catclaw Sensitivebriar
Groundplum Milkvetch
Wildindigo
Onion
Stiff stem Flax
Flax
Code
CRTE4
EUMA8
TRUR2
SACA
GERAN
SISYR
HEDEO
LAB
LAMIU
MARRU
MOPE
MONAR
SAPI3
ACAN
AMCA6
CAFA
DESE
KRAME
LESPE
LEVI7
NELU2
OXYTR
PECAN
PSTE3
SCUN
ASCA
BAPTI
ALLIU
LIRI
LINUM
(Continued)
-------
APPENDIX K (Continued)
to
ID
Family
Malvaceae
Malvaceae
Onagraceae
Oxalidaceae
Plantaginaceae
Polygonaceae
Polygonaceae
Polygonaceae
Ranunculaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Solanaceae
Solanaceae
Umbel 1 1 ferae
Urticaceae
Verbenaceae
Anacardiaceae
Anacardlaceae
Cactaceae
Cactaceae
Capri follaceae
Compos itae
Cornaceae
Cornaceae
Fagaceae
Genus
Callirhoe
Malvaceae
Oenothera
Oxalis
Plantago
Eriogonum
Polygonum
Rumex
Ranunculus
Diodia
Diodia
Galium
Houstonia
Physalls
Sol anum
Daucus
Urtica
Verbena
Rhus
Rhus
Ferocactus
Opuntia
Symphoricarpos
Chrysothamnus
Cornus
Cornus
Quercus
Species
involucrata
spp.
serrulata
corniculata
purshii
annuum
spp.
ellipticus
spp.
teres
virginiana
spp.
nigricans
moll is
rostratum
carota
spp.
spp.
WOODY
glabra
spp.
acanthodes
spp.
orbiculatus
viscidiflorus
drummondii
spp.
spp.
Common
Low Poppymallow
Mallow
Half shrub Sundrop
Yellow Woodsorrel
Woolly Plantain
Annual Wildbuckwheat
Smartweed
Dock
Buttercup spp.
Rough Buttonweed
Virginia Buttonweed
Bedstraw
Narrowleaf Bluet
Field Groundcherry
Buffalobur
Wild Carrot
Nettle
Verbena
PI ANTS----- - ._ ..
Smooth Sumac
Sumac
Cactus
Prickly Pear
Buckbrush
Rabbi tbrush
Roughleaf Dogwood
Dogwood
Oak
Code
CAIN2
MAL
OESE
OXCO
PLPA2
ERAN
POLYG
RUEL
Ranun
DITE2
DIVI3
GALIU
HONI
PHVIM
SORO
DACA6
URTIC
VERBE
RHGL
RHUS
FEAC
OPUNT
SYOR
CHVI
CODR
CORNU
QUERC
(Continued)
-------
APPENDIX K (Continued)
Family
Liliaceae
Pinaceae
Rosaceae
Rosaceae
Rosaceae
Rosaceae
Simaroubaceae
Ulmaceae
Ulmaceae
Genus
Yucca
Juniperus
Crataegus
Prunus
Rubus
Rubus
Ailanthus
Ulmus
Ulmus
Species
glauca
virgini ana
viridus
angusti folia
spp.
trivial is
altissima
americana
spp.
Common
Small Soapweed
Eastern Redcedar
Hawthorne
Chickasaw Plum
Blackberry spp.
Southern Dewberry
Tree-of-Heaven
American Elm
Elm
Code
YUGL
JUVI
CRVI
PRAN3
RUBUS
RUTR
HIAL
ULAM
ULMUS
co
o
o
-------
APPENDIX L
AVERAGE (N=25) CHEMICAL COMPOSITION (%, K±SE) IN ABOVE6ROUND VEGETATION
COMPONENTS ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY CATTLE
IN NORTH CENTRAL OKLAHOMA, 1976-78
TABLE L-l. AVERAGE (25 SAMPLES/DAY) NITROGEN (%) IN ABOVEGROUND
VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED BY
CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Live
Day!/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
*
2.24
1.91
1.81
1.49
1.37
1.30
1.42,
-_
-_
-_
._
2.27
1.24
1.13
~
1.23
.._
--
__
2.16
1.46
1.19
1.04
1.10
0.93
0.92
y
SE
0.05
0.07
0.08
0.06
0.07
0.10
, 0.09
-_
__
._
-_
0.16
0.05
0.04
--
0.07
-_
__
__
0.06
0.04
0.05
0.03
0.05
0.05
0.05
Standing
Dead
I
0.84
0.94
1.02
0.93
0.81
0.85
0.93
1.10
0.93
0.90
0.94
0.71
1.17
1.06
0.77
0.98
0.87
0.96
0.71
0.67
0.65
0.77
0.78
0.83
0.75
0.66
0.66
_.
0.72
SE
0.07
0.08
0.04
0.04
0.04
0.03
0.06
0.06
0.08
0.05
0.05
0.08
0.13
0.07
0.05
0.10
--
0.05
0.07
0.04
0.04
0.03
0.06
0.04
0.04
0.03
0.03
0.02
__
0.03
Ground
Litter
I
1.01
1.21
1.13
1.13
1.09
1.14
1.12
1.24
0.96
1.12
0.99
0.98
__
__
__
__
__
--
--
._
_.
__
__
--
..
__
--
SE
0.05
0.06
0.07
0.07
0.05
0.08
0.06
0.07
0.06
0.09
0.09
0.06
__
-_
__
-.
__
__
_.
--
__
_-
__
__
--
--
__
__
--
Dung
I
1.63
1.56
1.86
2.02
1.78
2.14
1.72
1.94
1.74
1.78
1.83
1.65
__
--
__
__
__
--
__
._
._
__
..
--
__
__
--
SE
0.03
0.05
0.06
0.05
0.05
0.05
0.03
0.06
0.04
0.05
0.06
0.05
--
__
__
__
_.
__
-_
__
--
__
_.
._
__
_.
-_
__
__
--
T,. ,a,.u year date: 6 = 1976; 6163 = 163 days after 1 Nov. 75.
^Standard error. ~~
Chemical analysis not conducted.
301
-------
TABLE 1-2. AVERAGE (25 SAMPLES/DAY) PHOSPHORUS (%) IN ABOVEGROUND
VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED BY
CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Live
Day!/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
X
0.18
0.16
0.11
0.07
0.08
0.09
0.093
__
__
0.11
0.10
0.07
0.09
__
_.
-.
0.20
0.11
0.09
0.08
0.09
0.08
0.15
SE^
0.00
0.01
0.01
0.01
0.01
0.01
, 0.01
__
__
__
0.01
0.01
0.00
0.01
__
_-
--
0.01
0.01
0.00
0.01
0.01
0.01
0.04
Standing
Dead
X
0.04
0.06
0.05
0.04
0.03
0.04
0.05
0.06
0.04
0.04
0.04
0.04
0.10
0.05
0.04
0.05
--
0.04
0.07
0.08
0.04
0.03
0.05
0.05
0.06
0.05
0.04
0.04
._
0.05
SE
0.003
0.006
0.003
0.003
0.002
0.003
0.005
0.006
0.004
0.004
0.003
0.007
0.023
0.005
0.006
0.005
0.004
0.009
0.007
0.003
0.003
0.007
0.005
0.005
0.004
0.004
0.003
__
0.000
Ground
Litter
X
0.06
0.09
0.08
0.09
0.06
0.07
0.06
0.07
0.06
0.07
0.09
0.06
_..
-_
--
--
--
-._
._
__
--
--
--
__
--
-_
._
__
--
SE
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
--
--
--
--
--
--
--
--
--
--
--
Dung
*
0.21
0.22
0.24
0.21
0.19
0.21
0.21
0.26
0.13
0.26
0.27
0.21
--
--
--
--
--
--
--
--
--
__
--
SE
0.01
0.02
0.02
0.01
0.02
0.01
0.01
0.03
0.02
0.02
0.02
0.01
__
-.
--
--
--
--
-_
__
-_
--
Y/Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
^Standard error.
Chemical analysis not conducted.
302
-------
TABLE L-3. AVERAGE (25 SAMPLES/DAY) POTASSIUM (%) IN ABOVEGROUND
VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED BY
CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Live
Dayl/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
X
1.90
1.60
1.37
1.28
1.17
1.22
1.17,.
__ 3/
--
__
__
__
__
1.68
1.37
1.13
._
1.35
__
_-
__
__
__
2.41
1.74
1.63
1.55
1.42
1.14
0.99
SE?/
0.08
0.08
0.04
0.06
0.09
0.06
0.07
__
-_
__
.._
-_
__
0.08
0.10
0.08
__
0.09
__
-_
-_
__
__
0.08
0.04
0.10
0.08
0.07
0.05
0.04
Standing
Dead
X
0.12
0.18
0.21
0.32
0.27
0.25
0.37
0.51
0.37
0.24
0.16
0.17
0.61
0.38
0.38
0.54
__
0.53
0.72
0.37
0.21
0.10
0.23 -
1.03
0.38
0.30
0.51
0.25
--
0.22
SE
0.01
0.02
0.02
0.03
0.02
0.02
0.04
0.05
0.03
0.03
0.03
0.06
0.13
0.06
0.04
0.05
__
0.02
0.06
0.05
0.02
0.02
0.05
0.20
0.06
0.03
0.03
0.02
__
0.02
Ground
Litter
X
0.16
0.25
0.22
0.22
0.20
0.20
0.21
0.23
0.21
0.21
0.20
0.19
--
--
--
__
--
_-
__
__
__
--
__
__
__
__
__
--
SE
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.01
0.03
--
--
_-
_.
_-
-_
..
..
__
_.
__
__
--
__
--
--
Dunq
X
0.17
0.18
0.23
0.23
0.22
0.20
0.20
0.20
0.25
0.31
0.32
0.21
__
--
--
__
__
__
__
__
__
__
__
__
__
._
__
__
--
SE
0.01
0.01
0.04
0.02
0.03
0.01
0.02
0.04
0.02
0.02
0.03
0.03
--
--
_-
-_
_-
-_
__
--
'
__
_.
__
__
__
__
-_
--
Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
TJyStandard Error.
'Chemical analysis not conducted.
303
-------
TABLE L-4. AVERAGE (25 SAMPLES/DAY) CALCIUM (%) IN ABOVEGROUND
VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED BY
CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Live
Day!/
6130
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
X
0.50
0.58
0.56
0.54
0.48
0.62
0.58,.
-_ I/
--
_-
__
__
__
0.59
0.55
0.55
0.66
__
__
__
._
0.62
0.57
0.64
0.64
0.61
0.59
0.54
SE2/
0.02
0.04
0.03
0.05
0.03
0.07
0.05
__
--
__
--
__
0.03
0.04
0.03
0.04
__
__
_.
__
_-.
0.03
0.04
0.06
0.04
0.05
0.06
0.06
Standing
Dead
X
0.44
0.56
0.51
0.48
0.51
0.49
0.52
0.38
0.45
0.50
0.45
0.39
0.49
0.50
0.44
0.57
--
0.25
0.48
0.42
0.49
0.34
0.43
0.42
0.42
0.41
0.46
0.45
--
0.47
SE
0.03
0.05
0.03
0.02
0.02
0.02
0.03
0.01
0.03
0.03
0.03
0.03
0.02
0.04
0.03
0.05
0.02
0.03
0.04
0.04
0.02
0.02
0.02
0.02
0.02
0.03
0.02
__
0.02
Ground
Litter
X
0.58
0.67
0.65
0.64
0.55
0.65
0.66
0.62
0.50
0.54
0.36
0.54
__
_-
__
--
--
_
__
--
__,
__
--
_-
__
__
--
SE
0.03
0.03
0.04
0.04
0.03
0.04
0.05
0.04
0.06
0.05
0.03
0.05
__
._
_.
--
__
--
__
__
_.
__
._
__
__
_-
_.
--
Dung
55
0.82
0.85
0.96
0.87
0.84
0.89
0.96
1.05
0.68
0.86
0.88
0.90
__
__
--
--
__
__
__
._
__
._
__
__
__
_«
__
_.
--
--
SE
0.04
0.05
0.04
0.04
0.05
0.03
0.03
0.07
0.04
0.03
0.05
0.02
__
__
__
-_
__
__
__
-_
__
__
_-
__
__
-_
_-
_ _
--
year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
|yStandard error.
-'Chemical analysis not conducted.
304
-------
TABLE L-5. AVERAGE (25 SAMPLES/DAY) ASH (%) IN ABOVE6ROUND VEGETATION
COMPONENTS ON A TALLGRASS PRAIRIE GRAZED BY CATTLE IN
NORTH CENTRAL OKLAHOMA, 1976-78
Live
Day!/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148 -
8176
8205
8233
8254
8290
8317
8343
*
.. 3/
__
__
7.5
7.8
6.9
6.6
7.2
__
--
--
--
8.5
7.8
8.0
7.9
7.9
7.7
--
s&
__
__
0.2
0.2
0.2
0.2
0.2
__
_.
__
12.0
0.3
0.1
0.2
0.2
0.2
0.3
--
Standing
Dead
*
_*
8.8
9.3
8.3
8.0
7.6
7.7
8.0
7.0
7.4
7.7
7.7
2.0
7.5
9.3
8.6
7.5
8.8
__
--
SE
0.5
9.3
0.3
0.3
0.2
0.3
0.3
0.2
0.5
0.6
0.3
0.3
0.7
0.4
0.3
0.4
__
--
i^Plant year date: 6 = 1976, 6163 = 163 days after 1 Nov 75.
-=_' C 4f *\ M A * Mw4 ^kU%W«««lM
^.Standard error.
'Chemical analysis not conducted.
305
-------
TABLE L-6. AVERAGE (25 SAMPLES/DAY) ACID DETERGENT FIBER (%) IN
ABOVEGROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE
GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Live
Day!/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
*
45.9
46.6
36.7
37.8
40.5
39.3
36.13,
__
__
_.
__
37.6
43.1
43.7
42.2
42.2
_.
--
--
--
30.7
37.6
40.6
39.0
39.0
36.9
--
s^
0.6
2.2
0.5
0.6
1.3
0.6
0.8
__
__
__
__
0.5
0.3
0.9
1.0
0.8
--
.
--
1.1
0.7
0.6
0.6
0.7
0.9
--
Standing
Dead
*
52.8
53.0
51.1
52.0
52.5
50.9
49.5
45.3
--
__
_-
__
47.0
53.1
54.2
53.0
53.2
49.8
45.1
49.8
53.3
51.9
52.1
48.7
51.9
50.3
50.9
51.3
SE
0.4
0.4
0.6
0.4
0.3
0.5
0.6
0.5
--
__
__
__
1.2
0.8
1.5
0.4
0.5
1.8
0.8
1.0
0.5
0.5
0.7
0.9
0.6
0.7
0.5
0.4
--
--
i^Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
^Standard error.
'Chemical analysis not conducted.
306
-------
TABLE L-7. AVERAGE (25 SAMPLES/DAY) ACID DETERGENT LIGNIN (%) IN
ABOVEGROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE
GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Live
Day!/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
I
11.4
14.9
14.9
11.8
10.1
10.2
10. 1,,
'
--
__
__
__
-_
6.9
9.2
11.3
10.1
9.3
._
__
_-
_.
-.
8.0
9.2
10.4
1.0
8.5
9.0
!&
0.4
1.3
1.2
0.5
1.0
0.4
0.6
._
__
__
__
..
__
0.2
0.2
0.4
0.3
0.3
__
__
__
__
__
0.4
0.6
0.4
0.4
0.7
0.5
--
Standing
Dead
*
13.1
12.7
17.5
12.3
12.3
13.3
14.0
11.3
__
__
__
9.0
10.1
10.7
13.5
13.9
14.8
12.7
13.8
10.8
14.0
11.6
13.0
12.6
15.0
12.9
11.4
__
SE
0.2
0.8
1.7
0.5
0.3
0.7
0.6
0.7
_.
__
__
-_
0.2
0.5
0.4
0.3
0.4
1.1
0.6
0.6
0.8
1.3
0.6
0.6
0.6
1.8
0.6
0.4
__
--
^Plant year date: 6 = 1976; 6163
r/Standard error.
'Chemical analysis not conducted.
= 163 days after 1 Nov 75.
307
-------
TABLE L-8. AVERAGE (25 SAMPLES/DAY) CELLULOSE (X) IN ABOVE6ROUND
VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED BY
CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Live
Da//
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
X
32.3
22.8
29.7
31.4
31.5
30.1
27.8,,
._ 1'
__
._
-_
._
__
29.8
31.4
31.6
30.6
31.6
._
__
__
__
--
23.9
31.2
32.4
31.7
30.7
28.0
--
SE!/
0.8
0.9
0.4
0.6
0.6
0.7
0.8
__
__
__
_-
..
__
0.4
0.3
0.8
0.8
0.8
__
__
__
__
-.
0.7
0.8
0.6
0.4
0.6
0.6
--
Standing
Dead
X
39.3
34.4
37.0
37.5
37.8
38.1
37.2
33.7
__
__
34.1
37.3
37.9
35.9
35.5
32.5
33.9
35.0
39.7
36.1
35.6
38.7
38.0
35.4
36.3
35.8
__
SE
0.5
1.5
1.8
0.3
0.6
0.6
0.6
0.8
__
-_
-_
0.9
0.4
0.8
0.4
0.7
1.1
0.7
0.8
1.1
0.9
1.6
0.8
0.6
0.8
0.4
0.4
__
--
i^Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov. 75.
^/Standard error.
-/Chemical analysis not conducted.
308
-------
TABLE L-9. AVERAGE (25 SAMPLES/DAY) DRY MATTER DIGESTIBILITY (X) IN
ABOVEGROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE
GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Live
Da//
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
X
_.3/
__
__
35.4
43.9
50.5
45.0
--
__
_-
__
__
__
48.2
46.8
49.1
47.2
38.8
_-
__
__
__
--
58.8
49.4
43.6
45.7
49.7
48.0
21.7
&'
__
__
1.5
1.0
1.2
2.2
__
__
__
__
__
2.1
1.0
0.9
1.1
0.8
_-
__
_.
__
_.
1.2
1.2
0.7
1.2
1.5
2.0
2.5
Standing
Dead
I
__
__
6.6
8.7
22.1
18.1
30.7
__
__
__
__
29.6
16.9
20.3
22.3
23.5
24.6
42.5
22.0
15.8
17.8
15.0
21.6
18.7
20.4
26.2
21.3
_-
--
SE
__
__
1.2
0.8
1.1
0.9
1.7
__
__
__
__
2.7
1.8
1.0
1.7
1.0
0.6
0.8
1.2
1.0
0.9
0.7
0.8
1.3
1.3
1.2
2.4
__
--
i^Plant year date: 6 = 1976; 6163
|yStandard error.
-/Chemical analysis not conducted.
163 days after 1 Nov 1975.
309
-------
TABLE L-10. AVERAGE (25 SAMPLES/DAY) ORGANIC MATTER DIGESTIBILITY (%)
IN ABOVEGROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE
GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
Live
Dayl/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
X
-I/
__
.-
__
_-
._
-_
--
__
-_
__
49.3
49.3
50.1
49.4
41.3
__
__
__
._
._
58.9
50.1
45.2
47.4
51.3
48.7
--
SEi/
__
--
__
_-
__
__
__
_.
--
__
__
_.
2.5
0.8
0.9
1.4
0.9
__
__
_.
__
__
2.6
1.2
0.7
1.1
1.4
1.9
Standing
Dead
X
..
__
__
__
__
__
__
__
__
--
__
__
28.7
21.9
23.5
26.2
26.4
26.4
44.0
23.6
18.0
19.6
15.6
23.4
19.5
22.2
26.9
48.2
__
~
SE
..
__
__
__
--
__
__
_.
-_
__
__
1.5
1.3
1.4
1.6
1.0
0.8
0.8
0.7
0.8
1.0
0.4
1.0
1.0
1.3
1.3
0.9
__
--
year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
TjyStandard error.
'Chemical analysis not conducted.
310
-------
APPENDIX M
AVERAGE (N=25) CHEMICAL YIELD (KG/HA, X±SE) IN ABOVEGROUND VEGETATION
COMPONENTS ON A TALLGRASS PRAIRIE WATERSHED GRAZED BY
CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-78
TABLE M-l. AVERAGE (25 SAMPLES/DAY) NITROGEN YIELD (KG/HA) IN ABOVE-
GROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-1978
Live
DAY-/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
*
14.5
27.4
28.0
37.5
33.5
32.9
42.2
26.1
27.2
31.7
22.3
17.9
__
__
__
__
__
--
._
__
__
--
-_
--
__
__
--
a*/
2.3
4.4
5.0
11.6
5.9
5.6
12.6
5.7
6.7
7.4
3.0
3.1
__
__
__
__
--
--
_-
--
_-
__
-.
_-
._
__
__
--
Standing
Dead
X
10.5
10.9
1.23
10.6
9.7
9.9
11.5
23.3
18.6
13.2
16.6
8.5
12.5
11.1
5.6
6.0
-_
7.1
15.5
11.0
8.8
10.5
7.1
6.1
7.0
7.6
6.8
7.5
__
10.4
SE
1.8
2.6
1.6
1.3
0.9
1.1
1.4
2.2
2.3
1.7
2.1
2.0
1.9
1.9
1.2
0.5
--
0.8
1.4
1.4
0.8
1.5
0.8
1.1
1.0
0.8
0.5
0.6
__
1.2
Ground
Litter
X
7.3
12.0
23.2
21.0
12.2
14.3.
13.9,
_.
--
_.
--
__
21.5
17.5
13.8
-_
15.0
--
_.
-.
_.
..
9.0
13.1
17.7
16.5
17.2
8.7
8.0
SE
1.1
0.8
2.5
1.7
1.0
1.4
t 2.2
-_
__
__
2.2
1.2
1.1
__
1.8
--
__
--
__
__
0.8
0.9
1.4
1.6
1.2
0.8
1.5
Total
X
32.3
51.2
63.5
69.0
55.4
57.0
67.5
49.4
45.7
45.4
38.9
26.3
SE
4.4
5.9
5.1
11.3
6.0
6.4
13.0
6.9
6.7
8.1
3.5
3.4
Y/Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
^Standard error.
-'Chemical analysis not conducted; Live included in Standing Dead 6346-
7160 and 7347-8148.
311
-------
TABLE M-2. AVERAGE (25 SAMPLES/DAY) PHOSPHORUS YIELD (KG/HA) IN ABOVE-
GROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-1978
Live
DAY-/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
«
0.92
2.54
1.97
3.08
1.96
1.99
2.69
1.71
1.45
1.68
1.93
1.07
-
..
N
_
.
.
_
-
.
.
-
_
_
.
. -
-
-
-
SEi/
0.15
0.67
0.51
1.03
0.41
0.36
0.97
0.58
0.30
0.39
0.32
0.24
_
_
_
.
_
_
.
_
_
-
-
-
.
_
-
-
-
-
Standing
Dead
X
0.57
0.59
0.58
0.44
0.43
0.53
0.57
1.18
0.92
0.56
0.62
0.43
0.92
0.35
0.27
0.29
-
0.32
1.12
1.21
0.47
0.40
0.40
0.36
0.52
0.54
0.41
0.42
-
0.78
SE
0.10
0.10
0.07
0.06
0.05
0.06
0.07
0.11
0.14
0.08
0.10
0.10
0.20
0.07
0.05
0.04
.
0.04
0.14
0.19
0.05
0.06
0.07
0.07
0.09
0.11
0.04
0.04
.
0.09
Ground
Litter
X
0.55
0.99
1.44
0.95
0.68
0.92
0.85,
_
_
_
.
-
1.04
1.36
0.82
_
1.06
_
_
_
_
-
0.86
1.02
1.33
1.28
1.42
0.73
1.37
SE
0.08
0.07
0.17
0.06
0.05
0.08
f 0.13
_
_
_
_
_
_
0.09
0.13
0.06
_
0.13
_
_
_
_ .
_
0.10
0.12
0.09
0.12
0.11
0.08
0.54
Total
X
2.04
4.21
4.00
4.46
3.07
3.33
4.12
2.89
2.37
2.30
2.55
1.50
-
-
SE
0.26
0.74
0.50
1.02
0.42
0.44
0.98
0.64
0.32
0.44
0.35
0.24
_
Y/Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
y/Standard error.
-'Chemical analysis not conducted; Live included in Standing Dead
6346-7160 and 7347-8148.
312
-------
TABLE M-3. AVERAGE (25 SAMPLES/DAY) POTASSIUM YIELD (KG/HA) IN ABOVE-
GROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-1978
Live
DAY-/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
X
8.3
5.6
5.4
6.4
5.5
5.3
7.4
4.9
5.7
7.3
4.6
4.1
_
-
_
-
_
.
-
.
_
-
-
_
_
-
-
-
.
-
^
1.4
0.9
0.9
1.4
0.7
0.8
2.2
1.2
1.0
1.7
0.5
1.0
_
-
-
-
_
_
-
-
_
-
-
_
-
-
_
-
.
-
Standing
Dead
X
6.2
1.7
2.3
3.4
3.1
2.9
4.2
10.0
7.3
3.2
2.6
1.2
4.9
2.7
2.6
3.1
_
4.4
11.2
5.5
2.6
1.4
1.9
8.7
2.8
3.0
5.1
3.0
.
2.9
SE
1.2
0.3
0.3
0.4
0.3
0.3
0.6
1.0
0.9
0.4
0.5
0.3
0.9
0.6
0.4
0.4
_
0.5
1.1
0.8
0.3
0.3
0.4
2.3
0.4
0.5
0.4
0.4
_
0.3
Ground
Litter
X
1.5
10.0
17.7
17.5
10.0
13.8
11.4,.
_ I/
, _
-
-
-
_
15.4
19.7
13.4
_
16.4
_
_
_
-
10.0
15.8
24.2
24.8
22.9
11.2
8.9
SE
0.2
0.7
1.9
1.3
0.7
1.2
1.7
-
-
_
_
_
1.0
1.9
0.9
_
1.9
_
_
_
_
0.9
1.3
2.0
2.4
1.8
1.2
1.6
Total
X
16.0
17.4
25.4
27.2
18.6
21.3
23.0
14.9
13.0
10.6
7.2
5.3
_
SE
2.3
1.4
2.0
1.9
1.1
1.7
3.1
1.8
1.4
1.9
0.7
1.0
_
i^Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
^/Standard error.
-'Chemical analysis not conducted; Live included in Standing
Dead 6346-7160 and 7347-8148.
313
-------
TABLE M-4. AVERAGE (25 SAMPLES/DAY) CALCIUM YIELD (KG/HA) IN ABOVE-
GROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE GRAZED
BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-1978
Live
DAY-i/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
X
8.3
15.4
17.9
21.2
16.9
20.1
29.1
13.1
14.9
13.5
8.6
10.8
_
_
_
_
_
-
_
_
_
_
_
_
_
_
-
_
.
SE^/
1.4
2.6
3.7
6.2
2.9
3.8
10.9
2.8
5.2
2.4
1.4
2.3
_
_
_
_
_
-
.
_
-
_
_
_
_
-
-
_
-
Standing
Dead
X
6.2
6.3
6.0
5.4
6.3
6.0
6.6
8.6
9.5
7.8
8.2
4.5
6.7
4.2
3.2
3.2
-
1.8
8.3
6.4
6.3
5.4
4.3
3.7
3.6
4.1
4.6
5.2
-
6.7
SE
1.2
1.2
0.7
0.7
0.7
0.6
0.8
0.9
1.2
1.1
1.2
0.9
1.2
0.8
0.5
0.2
-
0.2
0.9
0.8
0.5
0.9
0.6
0.9
0.5
0.4
0.3
0.5
-
0.8
Ground
Litter
X
1.5
3.6
7.4
7.2
4.3
6.8
6.2oy
- ZJ
-
_
-
-
_
5.4
8.0
6.7
«.
9.3
.
.
-
.
-
2.6
5.1
9.6
10.5
10.6
6.1
5.4
SE
0.2
0.3
1.0
0.7
0.4
0.9
1.3
_>
_
_
-
_
_
0.4
0.8
0.5
- ,
1.7
_
.
_
_
_
0.3
0.5
1.1
1.2
1.6
0.8
1.5
Total
X
16.0
25.7
31.2
33.8
27.6
30.5
42.9
21.7
24.5
20.8
16.8
15.3
-
SE
2.3
3.3
3.7
6.0
3.1
3.9
11.2
3.4
5.2
2.9
1.9
2.5
-
i^Plant year date: 6 = 1976; 6163 = 163 days after 1 Nov 75.
T/Standard error.
'Chemical analysis not conducted; Live included in Standing Dead
6346-7160 and 7347-8148.
314
-------
TABLE M-5. AVERAGE (25 SAMPLES/DAY) DIGESTIBLE DRY MATTER YIELD (KG/HA)
IN ABOVEGROUND VEGETATION COMPONENTS ON A TALLGRASS PRAIRIE
GRAZED BY CATTLE IN NORTH CENTRAL OKLAHOMA, 1976-1978
DAY!/
6163
6183
6206
6234
6262
6290
6320
6346
7010
7040
7090
7130
7160
7192
7220
7250
7275
7312
7347
8017
8050
8120
8148
8176
8205
8233
8254
8290
8317
8343
Live
X SE?/
-I/
_
_
110
128
342
285
684
_
_
_
-
321
255
209
152
232
208
788
342
235
313
221
247
209
229
269
305
_
Standing
Dead
X SE
.
_
_
26
20
41
38
65
_
_
_
-
46
35
34
18
35
22
63
47
35
45
26
44
29
30
17
33
_
Ground
Litter
X SE
-
_
522
484
662
537
_
_
_
_
-
_
443
674
606
489
513
_
_
_
_
_
256
442
650
744
911
576
262
Total
X SE
_
_
35
41
50
86
_
_
_
_
-
_
28
46
40
53
62
_
_
_
_
_
25
30
46
60
93
53
61
year date: 6 _ = 1976; 6163 = 163 days after 1 Nov 75.
Standard error.
Chemical analys
6346-7160 and 7347-8148.
^
-'Chemical analysis not conducted; Live included in Standing Dead
315
------- |