The field used to represent apple production in Oregon is located in Marion County, in the Willamette Valley. According to the 1997 Census of Agriculture, Oregon is among the major producers (7th to 8th overall) of apples for the fresh market 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 Cornelius silt loam. Cornelius silt loam, is a fine-silty, mixed, superactive, mesic Mollic Fragixeralfs. The series is used to produce berries, orchards, small grain and seed crop, hay and pasture. Cornelius silt loam is a moderately deep, moderately well drained, moderately slowly permeable soil with slow to medium runoff. The soil has a fragipan at about 2 feet. These soils formed in silt loess-like materials over mixed, fine-silty old alluvium of mixed origin. They are found on gently sloping to rolling low hills ans steep hill slopes with convex, long slopes and ridgetops at elevation of 350 to 800 feet above mean sea level. Slopes range from 2 to 60 percent. The series is not very extensive. Cornelius silt loam is a Hydrologic Group C soil.
|Starting Date||January 1, 1948||Meteorological File - Salem, OR (W24232)|
|Ending Date||December 31, 1983||Meteorological File - Salem, OR (W24232)|
|Pan Evaporation Factor (PFAC)||0.74||PRZM Manual Figure 5.1 (EPA, 1998)|
|Snowmelt Factor (SFAC)||0.15 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)||0.33 tons EI-1*||Farm Manual, Table 3.1 (EPA, 1985)|
|USLE LS Factor (USLELS)||3.64||Haan and Barfield, 1978|
|USLE P Factor (USLEP)||1.0||Set according to guidance (EPA, 2001)|
|Field Area (AFIELD)||172 ha||Area of Shipman Reservoir watershed (EPA, 1999)|
|NRCS Hyetograph (IREG)||2||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||Set to reside prior to new crop planting; forest floor or meadow.|
|Number of Different Crops (NDC)||1||Set to crops in simulation - generally one|
|Number of Cropping Periods (NCPDS)||36||Set to weather data. Salem, OR (W24232)|
|Maximum rainfall interception storage of crop (CINTCP)||0.25||Set to default for orchards (EPA, 2001)|
|Maximum Active Root Depth (AMXDR)||45 cm||Set to this limit due to soil fragipan. Some limited roots may tap below the top of the fragipan.|
|Maximum Canopy Coverage (COVMAX)||98||http://caf.wvu.edu/kearneysville/fruitloop.html Ross Byers, Horticultural Specialist VPI - canopy somewhat open between rows; 98% reasonable upper end estimate for the region|
|Soil Surface Condition After Harvest (ICNAH)||3||Orchards floor maintained similar to a meadow|
|Date of Crop Emergence
(EMD, EMM, IYREM)
|25/04||leaf-out, full canopy, leaf fall info from Steve Castagnoli, Hood River OR Extension|
|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)||0.040||RUSLE Project, A13OFOFN for orchards, no-till- Salem, OR (USDA, 2000)|
|USLE C Factor (USLEC)||0.005 - 0.034||RUSLE Project; A13OFOFN for orchards, no-till- Salem, OR (USDA, 2000)|
|Total Soil Depth (CORED)||148 cm||NRCS, National Soils Characterization Database (NRCS, 2001)|
|Number of Horizons (NHORIZ)||5 (4 Base with top split in two)|
|First, Second, Third, Fourth, and Fifth Soil Horizons (HORIZN = 1,2,3,4,5)|
|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).