The field used to represent apple production in Pennsylvania is located in Lancaster County, in south-eastern Pennsylvania. According to the 1997 Census of Agriculture, Pennsylvania is ranked 5th in apple production in the U.S. Within row tree spacing depends on the root stock and cultivation method. Spacing ranges from as little as 5 feet to 25 feet. Row spacing may be as much as twice the within row spacing to allow for maintenance and harvesting equipment. The soil selected to simulate the field is a benchmark soil, Elioak silt loam. Elioak silt loam, is a clayey, kaolinitic, mesic, Typic Hapludults. The soil is used for pastures, orchards, general local crops and non- agricultural uses. Elioak silt loam is a very deep, well drained, moderately permeable soil with medium to rapid runoff. These soils formed in residuum weathered from mica schists and phyllites, and to a minor extent from granitized schist and micaeous gneiss. They are found on summits and upper slopes in northern portions of the Piedmont Plateau. Most slopes are less than 15 percent, but can range from 0 to 30 percent. The series is of moderate extent in the mid-Atlantic Piedmont Plateau. Elioak silt loam is a Hydrologic Group C soil.
|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)||0.2 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)||0.42 tons EI-1*||PRZM Manual, Table 3.1 (EPA, 1985)|
|USLE LS Factor (USLELS)||3.60||Haan and Barfield, 1978|
|USLE P Factor (USLEP)||1.0||PRZM Table 5.6 (EPA, 1998)|
|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)||12%||Value set to maximum for crop (EPA, 2001)|
|Hydraulic Length (HL)||600 m||Shipman Reservoir (EPA, 1999)|
* EI = 100 ft-tons * in/ acre*hr
|Initial Crop (INICRP)||1||Set to one for all crops (EPA, 2001)|
|Initial Surface Condition (ISCOND)||3||Orchard - material is largely left in place|
|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)||0.25||Set to default for orchards (EPA, 2001)|
|Maximum Active Root Depth (AMXDR)||100 cm||Set to maximum soil depth. Roots may grow to 20 feet.|
|Maximum Canopy Coverage (COVMAX)||90||http://caf.wvu.edu/kearneysville/fruitloop.html
Ross Byers, Horticultural Specialist VPI - canopy somewhat open between rows; 90% reasonable upper end estimate.
|Soil Surface Condition After Harvest (ICNAH)||3||Orchards floor maintained similar to a meadow|
|Date of Crop Emergence
(EMD, EMM, IYREM)
|20/04||Personal communication w/ Ross Byers, VA Tech Fruit
Horticulturalist (540) 869-2560 x19|
Emergence based on leaf emergence, Maturation based on canopy maturity, Harvest based on average leaf fall. Dates based on central VA and modified by: 1 day added for every 100 miles north or 100 feet higher elevation or 1day subtracted for every 100 miles south or 100 feet lower elevation.
|Date of Crop Maturity
(MAD, MAM, IYRMAT)
|Date of Crop Harvest
(HAD, HAM, IYRHAR)
|Maximum Dry Weight (WFMAX)||0.0||Set to "0" Not used in simulation|
|SCS Curve Number (CN)||84, 79, 82||Gleams Manual Table A.3, meadow; condition good (USDA, 1990)|
|Manning's N Value (MNGN)||0.014||RUSLE Project, SB5OBOBC; Orchards, bare ground; conventional tillage; York, PA (USDA, 2000)|
|USLE C Factor (USLEC)||0.103 - 0.515||RUSLE Project; SB5OBOBC; Orchards, bare ground; conventional tillage; York, PA (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/|
|Bulk Density (BD)||
|Initial Water Content (THETO)||
|Compartment Thickness (DPN)||
|Field Capacity (THEFC)||
|Wilting Point (THEWP)||
|Organic Carbon Content (OC)|
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. 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).