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PENNSYLVANIA CORN
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The field used to represent corn production in Pennsylvania is located in Lancaster County in the south-east portion of the state. According to the 1997 Census of Agriculture, Pennsylvania is ranked 15th among major producers of corn in the U.S. The crop is generally planted the Spring (April) and harvested beginning in September. Continuous corn is practice is much of the region. However, rotation with other crops such as soybeans is also practiced. Most of the corn is planted for feed grain. Planting depth and row spacing (generally 30 inches) follows general practices for the U.S. Conventional tillage dominates management practices, followed by no-tillage. However, conservation tillage is continuing to grow. The soil selected to simulate the field is a benchmark soil, Hagerstown silt loam. Hagerstown silt loam, is a fine, mixed, semiactive, mesic Typic Hapludalfs. These soils are used fro general crops, pastures, orchards and truck crops. Large portions are in non-farm uses. Hagerstown silt loam is a very deep, well drained, moderately permeable soil with moderate to rapid runoff. These soils formed in materials weathered from hard grey limestone of rather high purity. They are found on valley floors and the adjacent hills. In some areas rock outcrops are common surface features. Slopes are generally less than 15 percent, but may range up to 45 percent. Hagerstown silt loam is a Hydrologic Group C soil.
| Parameter | Value | Source |
|---|---|---|
| Starting Date | January 1, 1948 | Meteorological File - Allentown, PA (W14737) |
| Ending Date | December 31, 1983 | Meteorological File - Allentown, PA (W14737) |
| Pan Evaporation Factor (PFAC) | 0.76 | PRZM Manual Figure 5.1 (EPA, 1998.) |
| Snowmelt Factor (SFAC) | 0.20m 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) | 0.32 tons EI-1* | GLEAMS Manual, table of Representative Soils (USDA, 1990) |
| USLE LS Factor (USLELS) | 1.042 | GLEAMS Manual, table of Representative Soils (USDA, 1990) |
| USLE P Factor (USLEP) | 0.5 | Set according to guidance (EPA, 2001) |
| Field Area (AFIELD) | 172 ha | Area of Shipman Reservoir watershed (EPA, 1999) |
| NRCS Hyetograph (IREG) | 3 | PRZM Manual Figure 5.12 (EPA, 1998) |
| Slope (SLP) | 6% | Maximum value for row crop. (EPA, 2001). Most slopes for soil series are around 2 percent. |
| Hydraulic Length (HL) | 600 m | Shipman Reservoir (EPA, 1999) |
* 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 | Set fallow prior to new crop planting |
| Number of Different Crops (NDC) | 1 | Set to crops in simulation - generally one |
| Number of Cropping Periods (NCPDS) | 36 | Set to weather data. Allentown, PA (W14737) |
| Maximum rainfall interception storage of crop (CINTCP) | 0.17 | PRZM, Table 5.4 (EPA, 1998) |
| Maximum Active Root Depth (AMXDR) | 90 cm | PRZM Manual, Table 5.9 (EPA, 1998) |
| Maximum Canopy Coverage (COVMAX) | 100 | QA/QC Guidance (EPA, 2001) |
| Soil Surface Condition After Harvest (ICNAH) | 3 | Winter cover crop planted in most areas. |
| Date of Crop Emergence (EMD, EMM, IYREM) |
20/04 | Usual Planting and Harvesting Dates for U.S. Field Crops and Penn. State Coop. Extension |
| Date of Crop Maturity (MAD, MAM, IYRMAT) |
04/07 | |
| Date of Crop Harvest (HAD, HAM, IYRHAR) |
01/10 | |
| Maximum Dry Weight (WFMAX) | 0.0 | Set to "0" Not used in simulation |
| SCS Curve Number (CN) | 89, 83, 85 | Gleams Manual Table A.3, Fallow SR/CT; Cropping and Residue = Row crop, Conservation tillage, Contour plowing (USDA, 1990) |
| Manning's N Value (MNGN) | 0.014 | RUSLE Project, SB5CGSBC, Corn, grain, conventional tillage, York, PA (USDA, 2000) |
| USLE C Factor (USLEC) | 0.025 - 0.701 | RUSLE Project; SB5CGSBC, Corn, grain, conventional tillage, York, PA (USDA, 2000) |
| Parameter | Value | Verification Source |
|---|---|---|
| Total Soil Depth (CORED) | 100 cm | NRCS, National Soils Characterization Database (NRCS, 2001) |
| Number of Horizons (NHORIZ) | 3 | |
| 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/
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| 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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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).