CALIFORNIA COTTON (Southern)
The field used to represent cotton production in California is located in Fresno County in the Central Valley, although cotton production occurs throughout the Central Valley. According to the 1997 Census of Agriculture, California is the major producer of cotton in the U.S. Cotton is generally grown on the alluvial fans and basin rims by both dry and wet seeded methods. Row spacing and planting depths are consistent with other cotton growing regions of the U.S. Both standard (30-inch) and ultra-narrow (20-inch) row spacing are used. Irrigation is mostly by flooding. The soil selected to simulate the field is a Twisselman clay. Twisselman clay is a fine, mixed, calcareous, thermic Typic Torriorthents. These soils are often used for cotton production under irrigation. Twisselman clay is a deep, well drained, slow to medium runoff, slowly permeable (very slow in saline-alkali phases) soil that formed in alluvium mainly from sedimentary rock sources. These soil are generally found on alluvial fans and basin rims at elevations of 200 to 1,000 feet above mean sea level and have slopes of 0 to 5 percent. The soil is of moderate extent. Twisselman clay is a Hydrologic Group C soil.
|Starting Date||January 1, 1948||Meteorological File - Southern: Bakersfield, CA (W23155)|
|Ending Date||December 31, 1983||Meteorological File - Southern: Bakersfield, CA (W23155)|
|Pan Evaporation Factor (PFAC)||0.7||PRZM Manual Figure 5.1 (EPA, 1998)|
|Snowmelt Factor (SFAC)||0.5 cm C- 1||PRZM Manual Table 5.1 (EPA, 1998)|
|Minimum Depth of Evaporation (ANETD)||17.0 cm||PRZM Manual Figure 5.2 (EPA, 1998)|
|Method to Calculate Erosion (ERFLAG)||4 (MUSS)||PRZM Manual (EPA, 1998)|
|USLE K Factor (USLEK)||0.21 tons EI-1*||PRZM Input Collator (Burns, 1992) and FARM Manual (EPA, 1985)|
|USLE LS Factor (USLELS)||0.02||Haan and Barfield, 1979|
|USLE P Factor (USLEP)||1.0||PRZM Manual (EPA,1998)|
|Field Area (AFIELD)||172 ha||Area of Shipman Reservoir watershed (EPA, 1999)|
|NRCS Hyetograph (IREG)||1||PRZM Manual Figure 5.12 (EPA, 1998)|
|Slope (SLP)||2.5%||Mid-point of soil series range (EPA, 2001)|
|Hydraulic Length (HL)||600 m||Shipman Reservoir (EPA, 1999)|
|Irrigation Flag (IRFLAG)||2 (cropping period only)||Based on recommendations from farm advisors for general flooding for crop irrigation|
|Irrigation Type (IRTYP)||1 (Flood)||Based on recommendations from farm advisors for general flooding for crop irrigation|
|Leaching Factor (FLEACH)||0.1||Estimated|
|Fraction of Water Capacity when Irrigation is Applied (PCDEPL)||0.55||Based on recommendations from farm advisors for general flooding for crop irrigation|
|Maximum Rate at which Irrigation is Applied (RATEAP)||0.4 cm hr-1||PRZM Manual, Table 5.33 (EPA, 1998)|
* EI = 100 ft-tons * in/ acre*hr
|Initial Crop (INICRP)||1||Set to one for all crops (EPA, 2001)|
|Initial Surface Condition (ISCOND)||1||Kerry Arroues USDA-NRCS|
|Number of Different Crops (NDC)||1||Set to crops in simulation - generally one|
|Number of Cropping Periods (NCPDS)||36||Set to weather data. Meteorological File - Bakersfield, CA (W23155)|
|Maximum rainfall interception storage of crop (CINTCP)||0.2||PIC; confirmed using Table 5.4 from PRZM Manual (Burns, 1992 and EPA, 1985)|
|Maximum Active Root Depth (AMXDR)||65 cm||Kerry Arroues USDA-NRCS|
|Maximum Canopy Coverage (COVMAX)||100||Kerry Arroues USDA-NRCS|
|Soil Surface Condition After Harvest (ICNAH)||3||Kerry Arroues USDA-NRCS|
|Date of Crop Emergence
(EMD, EMM, IYREM)
|05/05||Usual Planting and Harvesting Dates for U.S. Field Crops (USDA, 1984)|
|Date of Crop Maturity
(MAD, MAM, IYRMAT)
|03/01||Usual Planting and Harvesting Dates for U.S. Field Crops (USDA, 1984)|
|Date of Crop Harvest
(HAD, HAM, IYRHAR)
|11/11||Usual Planting and Harvesting Dates for U.S. Field Crops (USDA, 1984)|
|Maximum Dry Weight (WFMAX)||0.0||Set to "0" Not used in simulation|
|SCS Curve Number (CN)||89, 86, 87||Set to MS Cotton values. Field validated curve numbers.|
|Manning's N Value (MNGN)||0.023||RUSLE Project; C23CTCTC; Cotton, conventional tillage, Fresno (USDA, 2000)|
|USLE C Factor (USLEC)||0.54 - 0.412||RUSLE Project; C23CTCTC; Cotton, conventional tillage, Fresno, Variable with date (USDA, 2000)|
|Total Soil Depth (CORED)||100 cm||NRCS, National Soils Characterization Database (NRCS, 2001)|
|Number of Horizons (NHORIZ)||3 (Top horizon split in two)|
|First, Second, and Third Soil Horizons (HORIZN = 1,2,3)|
|Horizon Thickness (THKNS)||
||NRCS, National Soils Characterization Database (NRCS, 2001) http://soils.usda.gov/survey/nscd/
Ed Russell (USDA-NRCS, Fresno)
|Bulk Density (BD)|
|Initial Water Content (THETO)|
|Compartment Thickness (DPN)|
|Field Capacity (THEFC)|
|Wilting Point (THEWP)|
|Organic Carbon Content (OC)|
Burns. 1992. Burns, L.A., (Coordinator), B.W. Allen, Jr., M.C. Barber, S.L. Bird, J.M. Cheplick, M.J. Fendley, D.R. Hartel, C.A. Kittner, F.L. Mayer, Jr., L.A. Suarez, and S.E. Wooten. Pesticide and Industrial Chemical Risk Analysis and Hazard Assessment, Version 3.0. (PIRANHA) Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Athens, GA. 1992.
EPA. 1985. Field Agricultural Runoff Monitoring (FARM) Manual, (EPA/600/3-85/043) Environmental Research Laboratory, U.S. Environmental Protection Agency, Athens, GA.
EPA. 1998. Carsel, R.F., J.C. Imhoff, P.R. Hummel, J.M. Cheplick, and A.S. Donigian, Jr. PRZM-3, A Model for Predicting Pesticide and Nitrogen Fate in the Crop Root and Unsaturated Soil Zones: Users Manual for Release 3.0. National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Athens, GA.
EPA. 1999. Jones, R.D., J. Breithaupt, J. Carleton, L. Libelo, J. Lin, R. Matzner, and R. Parker. Guidance for Use of the Index Reservoir in Drinking Water Exposure Assessments. Environmental Fate and Effects Division, Office of Pesticide Programs, U.S. Environmental Protection Agency, Washington. D.C.
EPA. 2001. Abel, S.A. Procedure for Conducting Quality Assurance and Quality Control of Existing and New PRZM Field and Orchard Crop Standard Scenarios. Environmental Fate and Effects Division, Office of Pesticide Programs, U.S. Environmental Protection Agency, Washington, D.C.
Haan, C.T. and B.J. Barfield. 1978. Hydrology and Sedimentology of Surface Mined Lands. Office of Continuing Education and Extension, College of Engineering, University of Kentucky, Lexington, Kentucky 40506. pp. 286.
USDA. 1984. Usual Planting and Harvesting Dates for U.S. Field Crops, Statistical Reporting Service, U.S. Department of Agriculture, Agriculture Handbook #628, pp.78.
USDA. 1990. Davis, F.M., R.A. Leonard, W.G. Knisel. GLEAMS User Manual, Version 1.8.55. USDA-ARS Southeast Watershed Research Laboratory, Tifton GA. SEWRL-030190FMD.
USDA. 2000. Revised Universal Soil Loss Equation (RUSLE) EPA Pesticide Project. U.S. Department of Agriculture, National Resources Conservation Service (NRCS) and Agricultural Research Service (ARS).