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CALIFORNIA TOMATOES (Northern and Southern)
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The field used to represent tomato production in California is located in San Joaquin County in the Central Valley, although tomatoes are produced throughout the Central Valley and Imperial Valley. According to the 1997 Census of Agriculture, California is ranked 2nd in the U.S. in production; 45 percent of California's production is in Stanislaus and Merced Counties. Tomatoes are generally grown on raised beds 60-66 inches wide. Most tomato plants are from transplants grown in nurseries. Row spacing is approximately 30 to 45 inches and plants are grown close together within rows. Spaces between rows are generally kept clear, but plants often grow into these areas. The soil selected to simulate the field is a Stockton clay. Stockton clay is a fine, semectitic, thermic Xeric Epiaquerts. These soils are often used for tomato production under irrigation, but also for other row crops such as corn, beans, sugar beets, and grains. Stockton clay is a deep, somewhat poorly drained, slowly permeable, very slow to slow runoff soil that formed in alluvium of mixed igneous and sedimentary rock sources. These soil are generally found in basins and in swales of drainageways. They are located at elevation of 0 to 100 feet above mean sea level and have slopes of 0 to 2 percent. The soil is of moderate extent. Stockton clay is a Hydrologic Group D soil.
| Parameter | Value | Source |
|---|---|---|
| Starting Date | January 1, 1948 | Meteorological File - Southern: Bakersfield, CA (W23155) Northern: Sacramento, CA (W23232) |
| Ending Date | December 31, 1983 | Meteorological File - Southern: Bakersfield, CA (W23155) Northern: Sacramento, CA (W23232) |
| Pan Evaporation Factor (PFAC) | 0.7 | PRZM Manual Figure 5.1 (EPA, 1998) |
| Snowmelt Factor (SFAC) | 0.55 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) |
| Parameter | Value | Source |
|---|---|---|
| Method to Calculate Erosion (ERFLAG) | 4 (MUSS) | PRZM Manual (EPA, 1998) |
| USLE K Factor (USLEK) | 0.24 tons EI-1* | NRI - Average value listed for the soil series Stockton |
| USLE LS Factor (USLELS) | 0.26 | NRI - Average value listed for the soil series Stockton |
| USLE P Factor (USLEP) | 1.0 | NRI - Average value listed for the soil series Stockton |
| 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) | 0.25% | Bob Mullen San Joaquin County Cooperative Extension. 209-468-9489 |
| 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 |
| Flow rate of water entering furrow (Q0) | 0.0025 m3s-1 | PRZM Manual, Table 5.35 (EPA, 1998) |
| Bottom width of furrow (BT) | 0.12m | Estimated based on 10-inch furrow width |
| Furrow side slope (ZRS) | 2 | PRZM Manual (EPA, 1998) |
| Furrow slope (SF) | 0.005 | Maximum field slope |
| Manning's N for furrow (EN) | 0.02 | PRZM Manual, Table 5.34 (EPA, 1998) |
| Furrow length (X2) | 300m | PRZM Manual, Table 5.35 (EPA, 1998) |
| Irrigation Type (IRTYP) | 2 (Flood) | Based on recommendations from farm advisors for general flooding for crop irrigation |
| Leaching Factor (FLEACH) | 0.4 | 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) | 0.15 cm hr-1 | PRZM Manual, Table 5.33 (EPA, 1998) |
* EI = 100 ft-tons * in/ acre*hr
| Parameter | Value | Source |
|---|---|---|
| Initial Crop (INICRP) | 1 | Set to one for all crops (EPA, 2001) |
| Initial Surface Condition (ISCOND) | 1 | Bob Mullen San Joaquin County Cooperative Extension. 209-468-9489 |
| 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) or Sacramento, CA (W23232) |
| Maximum rainfall interception storage of crop (CINTCP) | 0.1 | PIC; confirmed using Table 5.4 from PRZM Manual (Burns, 1992 and EPA, 1985) |
| Maximum Active Root Depth (AMXDR) | 90 cm | Bob Mullen San Joaquin County Cooperative Extension. 209-468-9489 |
| Maximum Canopy Coverage (COVMAX) | 90 | Bob Mullen San Joaquin County Cooperative Extension. 209-468-9489 |
| Soil Surface Condition After Harvest (ICNAH) | 1 | Bob Mullen San Joaquin County Cooperative Extension. 209-468-9489 |
| Date of Crop Emergence (EMD, EMM, IYREM) |
01/03 | Bob Mullen San Joaquin County Cooperative Extension. 209-468-9489 |
| Date of Crop Maturity (MAD, MAM, IYRMAT) |
01/07 | Bob Mullen San Joaquin County Cooperative Extension. 209-468-9489 |
| Date of Crop Harvest (HAD, HAM, IYRHAR) |
01/09 | Bob Mullen San Joaquin County Cooperative Extension. 209-468-9489 |
| Maximum Dry Weight (WFMAX) | 0.0 | Set to "0" Not used in simulation |
| SCS Curve Number (CN) | 91, 87, 88 | Gleams Manual Table A.3, Fallow = Fallow, SR/ poor; Cropping and Residue = Row Crops SR/poor condition |
| Manning's N Value (MNGN) | 0.023 | RUSLE Project; C23BDCGC for dry beans, 2000 lb, Fresno (USDA, 2000) |
| USLE C Factor (USLEC) | 0.035- 0.255 | RUSLE Project; C23BDCGC for dry beans, 2000 lb, Fresno Variable with date (USDA, 2000) |
| Parameter | Value | Verification Source |
|---|---|---|
| Total Soil Depth (CORED) | 180 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) |
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NRCS, National Soils Characterization Database (NRCS, 2001) http://soils.usda.gov/survey/nscd/
 Edd Russell (USDA-NRCS, Fresno) |
| Bulk Density (BD) |
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| Initial Water Content (THETO) |
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| Compartment Thickness (DPN) |
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| Field Capacity (THEFC) |
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| Wilting Point (THEWP) |
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| Organic Carbon Content (OC) |
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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. 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.
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).