The field used to represent corn production in South Texas is representative of a field in Hildago and Cameron counties, located in the Lower Rio Grande Valley region. The meteorological file, Brownsville, TX, represents the MLRA region 83D. Texas produces 2 percent of the U. S. commercially grown corn ( NSF 1999). The Northern High Plains grows approximately 66 percent of Texas corn with less than 12 percent being grown in the Lower Valley region. In the Lower Valley region of Texas, corn is planted between late January and Late February. In the Northern parts of the state, planting dates are significantly different, being mid April to early May. Corn is generally planted in 30 inch rows at rates of 28,000  34,000 seeds/ acre. Corn is generally irrigated andharvested in the lower valley between late June and Mid July ( NSF 1999). The soil in Hildago and Cameron counties is alluvial, being derived from the Rio Grande ( USDA 1997). Thus there is no dominant soil type ( range of coverages: 0.1 13.2%). For this scenario, Harlingen Clay was selected as a representative soil type because it has significant yields of corn and has the largest percent coverage of a hydrologic group C or D soil for Hildago ( 4.8 %) and Cameron ( 6.6 %) counties ( USDA 2004). Harlingen Clay is a hydrologic group D soil that is classified as very fine, smectitic, hyperthermic sodic haplusterts. The Harlingen series of soils is deep, moderately well drained, very slowly permeable soils that formed in clayey sediments. These soils have slopes of 0 1 percent and occur on stream terraces and deltas along the lower portions of the Rio Grande River and its tributaries in south Texas and Mexico. This soil is mostly used for irrigated crop land including cotton and cool season vegetables ( USDA1997).

PRZM 3.12 Scenario Input Parameters for Hidalgo/ Cameron Counties, Texas  Corn Parameter Value Source Starting Date January 1, 1961 Meteorological File  Brownsville, Cameron County, Texas: W12919 Ending Date December 31, 1990 Meteorological File  Brownsville, Cameron County, Texas: W12919 Pan Evaporation Factor ( PFAC) 0.69 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.0 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD) 32.5 cm PRZM Manual Figure 5.2 ( EPA, 1998) Section II. D. 6  Page 59 of 120 Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.32 tons EI 1* Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) USLE LS Factor ( USLELS) 0.15 Based on slope taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) , PRZM manual length 400 m, 0.5% slope USLE P Factor ( USLEP) 1 contour plowing is not common due to 0 1% slope ( consulted with extension agent) Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA 2004) NRCS Hyetograph ( IREG) 3 PRZM Manual Figure 5.12 ( EPA, 1998)

Slope ( SLP) 0.5% From http:// soils. usda. gov/ official soil series description ( slope range = 0 1%) Hydraulic Length ( HL) 356 ( pond) 464 ( reservoir) Shipman Reservoir ( EPA 2004)

Irrigation Flag ( IRFLAG) 0 From PRZM Scenario Guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Leaching Factor ( FLEACH) Not applicable Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops (. EPA 2004) Initial Surface Condition ( ISCOND) 2 PRZM Scenario Guidance ( 2004)

Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data.

Maximum rainfall interception storage of crop ( CINTCP) 0.25 cm Maximum recommended value for grass ( Carsel et al. 1998)

Maximum Active Root Depth ( AMXDR) 90 cm PRZM Manual ( Carsel et al., 1998)

Maximum Canopy Coverage ( COVMAX) 100% PRZM Manual ( Carsel et al., 1998)

Soil Surface Condition After Harvest ( ICNAH) 2 PRZM Manual ( Carsel et al., 1998), 2 = cover crop consulted with extension agent, crops are rotated Section II. D. 6  Page 60 of 120 Date of Crop Emergence ( EMD, EMM, IYREM) 1/ 3/ 61 corn is planted late January Late February ( TX extension crop profile) + emergence of 5 15 days ( PRZM manual) Date of Crop Maturity ( MAD, MAM, IYRMAT) 15/ 6/ 61 mature 110 130 days from planting ( PRZM manual)

Date of Crop Harvest ( HAD, HAM, IYRHAR) 1/ 7/ 61 corn is harvested between late June and mid July ( http:// pestdata. ncsu. edu/ cropprofiles)

Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 88, 89, 90 Gleams Manual Table A. 3, ( Hydrological soil D) Row Crop, SR, good hydrologic condition ( moderately well drained soil) ( USDA, 1990) Manning's N Value ( MNGN) .014 RUSLE Project, TX Galveston Corn, ( T95CGSBC) USLE C Factor ( USLEC) .536 .581 .622 .654 .680 .705 .800 .829 .843 .821 .774 .602 .452 .371.311.282 .285 .287 .288 .307 .369 .388 .039 .042 .133 .173 .215 .257 RUSLE Project, TX Galveston Corn, ( T95CGSBC)

Soil Parameters Total Soil Depth ( CORED) 180 cm http:// soils. usda. gov/ ( 71 inches)

Number of Horizons ( NHORIZ) 4 ( top HORIZN split in 2) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 18 cm ( HORIZN = 2) 61 cm ( HORIZN = 3) 91 cm ( HORIZN = 4) Bulk Density ( BD) 1.45g cm 3 ( HORIZN = 1) 1.45g cm 3 ( HORIZN = 2) 1.40 g cm 3 ( HORIZN = 3) 1.55 g cm 3 ( HORIZN = 4) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Initial Water Content ( THETO) 0.39 cm3 H20 cm3 soil ( HORIZN = 1 4) Field Capacity values, PRZM Scenario Guidance ( 2004) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 1 cm ( HORIZN = 2) 1 cm ( HORIZN = 3) 1 cm ( HORIZN = 4) PRZM Scenario Guidance ( 2004)

Field Capacity ( THEFC) 0.39 cm3 H20 cm3 soil ( HORIZN = 1 4) GLEAMS Table H 3 ( 1990)

Wilting Point ( THEWP) 0.28 cm3 H20 cm3 soil ( HORIZN = 1 4) GLEAMS Table H 3 ( 1990)

Organic Carbon Content ( OC) 1.2% ( HORIZN = 1) 1.2% ( HORIZN = 2) 0.9% ( HORIZN = 3) 0.45% ( HORIZN = 4) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/); Adjusted using the relationship % OC = 0.6 x % Organic Matter ( Doucette 2000) Section II. D. 6  Page 61 of 120 G. North / Northcentral Scenario Documentation 1. Pennsylvania Apples ( PAappleC)

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 nonagricultural 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.

PRZM 3.12 Scenario Input Parameters for Lancaster, PA  Apples Parameter Value Source Starting Date January 1, 1961 Meteorological File  Allentown, PA ( W14737) Ending Date December 31, 1990 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)

Erosion and Landscape Parameters 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) 464 m Shipman Reservoir ( EPA, 1999) Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Section II. D. 6  Page 62 of 120 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/ kearneyville/ 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 Date of Crop Maturity ( MAD, MAM, IYRMAT) 10/ 05 Date of Crop Harvest ( HAD, HAM, IYRHAR) 15/ 10 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. 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) Elioak Soil Parameters Total Soil Depth ( CORED) 100 cm Number of Horizons ( NHORIZ) 3 ( Top horizon split in two) NRCS, National Soils Characterization Database ( NRCS, 2001)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 28 cm ( HORIZN = 2) 62 cm ( HORIZN = 3) Bulk Density ( BD) 1.70 g cm 3 ( HORIZN = 1,2) 1.80 g cm 3 ( HORIZN = 3) Initial Water Content ( THETO) 0.218 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.243 cm3 H2O cm3 soil ( HORIZN = 3) NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/) Section II. D. 6  Page 63 of 120 Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 2 cm ( HORIZN = 2) 2 cm ( HORIZN = 3) Field Capacity ( THEFC) 0.218 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.243cm3 H2O cm3 soil ( HORIZN = 3) Wilting Point ( THEWP) 0.098 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.163 cm3 H2O cm3 soil ( HORIZN = 3) Organic Carbon Content ( OC) 1.16% ( HORIZN = 1,2) 0.174 ( HORIZN = 3)

2. Pennsylvania Alfalfa ( PAalfalfaC)

The field used to represent alfalfa production in Pennsylvania is located in York County in south central Pennsylvania. According to the 1997 Census of Agriculture, Pennsylvania is ranked 15th overall in the production of alfalfa in the U. S. Alfalfa is a perennial crop, grown on a variety of soils, planted early in the year and maintained under continuous cultivation on a 3 to 5 year cycle at which time a new crop is planted. Planting depths range from 0.25 to 1.0 inches, depending on soil texture, on level seed beds. Row spacing is approximately 30 inches; alfalfa is not irrigated in Pennsylvania. Cuttings range from 2 to 4 per year. Most farmers take the last cutting of the season in September. Alfalfa prefers well drained soils with a pH near neutral ( pH 6.7 6.9). The soil selected to simulate the field is a benchmark soil, Glenville silt loam. Glenville silt loam, is a fine loamy, mixed, active, mesic, Aquic Fragiudults. These soils are in general crop production, but mostly grain, hay and pasture. Glenville silt loam is a very deep, moderately well drained or somewhat poorly drained, medium to slowly permeable soil with medium to slow runoff and consists of a fragipan at approximately 2 feet. In the fragipan, permeability is slow to moderately slow. These soils formed in residuum weathered from mica acid schist and crystalline rock containing mica. They are found on nearly level to strongly sloping upland flats, footslopes, or near the heads of drainageways. Slopes range from 0 to 15 percent. These soils are extensive in the mid Atlantic Piedmont. Glenville silt loam is a Hydrologic Group C soil.

PRZM 3.12 Scenario Input Parameters for York County, Pennsylvania  Alfalfa Parameter Value Source Starting Date January 1, 1961 Meteorological File  Allentown, PA ( W14737) Ending Date December 31, 1990 Meteorological File  Allentown, PA ( W14737) Pan Evaporation Factor ( PFAC) 0.76 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.3 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998) Minimum Depth of Evaporation ( ANETD) 12.5 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998) Section II. D. 6  Page 64 of 120 USLE K Factor ( USLEK) 0.33 tons EI 1* FARM Manual, Table 3.1 ( EPA, 1985)

USLE LS Factor ( USLELS) 0.123 Haan and Barfield, 1978.

USLE P Factor ( USLEP) 0.60 Leon Restler, Ag. Extension Agent, Lancaster Co. ( 717) 394_ 6851 8/ 14/ 01) 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% Leon Restler, Ag. Extension Agent, Lancaster Co. ( 717) 394_ 6851 8/ 14/ 01) Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Initial Surface Condition ( ISCOND) 1 Set to fallow prior to new crop planting.

Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Allentown, PA ( W14737)

Maximum rainfall interception storage of crop ( CINTCP) 0.25 PRZM, Table 5.4 ( EPA, 1998)

Maximum Active Root Depth ( AMXDR) 120 cm Leon Restler, Ag. Extension Agent, Lancaster Co. ( 717) 394_ 6851 8/ 14/ 01) Maximum Canopy Coverage ( COVMAX) 100 Leon Restler, Ag. Extension Agent, Lancaster Co. ( 717) 394_ 6851 8/ 14/ 01) Soil Surface Condition After Harvest ( ICNAH) 3 Set to residue for winter months after last harvest during multi year growth and during winter of last years of growth. Date of Crop Emergence ( EMD, EMM, IYREM) 15/ 04 Date of Crop Maturity ( MAD, MAM, IYRMAT) 31/ 10 Date of Crop Harvest ( HAD, HAM, IYRHAR) 31/ 10 Leon Restler, Ag. Extension Agent, Lancaster Co. ( 717) 394_ 6851 8/ 14/ 01)

Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 87, 83, 86 Gleams Manual Table A. 3, pasture/ range, non_ CNT, poor condition ( USDA, 1990) Manning's N Value ( MNGN) 0.110 RUSLE Project, SB5HLHLC; Hay, legume, conventional till, York ( USDA, 2000) USLE C Factor ( USLEC) 0.001  0.017 RUSLE Project; SB5HLHLC; Hay, legume, conventional till, York ( USDA, 2000) Glenville Soil Parameters Total Soil Depth ( CORED) 120 cm NRCS, National Soils Characterization Database ( NRCS, 2001) Section II. D. 6  Page 65 of 120 Number of Horizons ( NHORIZ) 3 ( Top horizon split in two) Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 12 cm ( HORIZN = 2) 98 cm ( HORIZN = 3) Bulk Density ( BD) 1.4 g cm 3 ( HORIZN = 1,2) 1.8 g cm 3 ( HORIZN = 3) Initial Water Content ( THETO) 0.254 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.201 cm3 H2O cm3 soil ( HORIZN = 3) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 2 cm ( HORIZN = 2,3) Field Capacity ( THEFC) 0.254 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.201cm3 H2O cm3 soil ( HORIZN = 3) Wilting Point ( THEWP) 0.094 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.121 cm3 H2O cm3 soil ( HORIZN = 3) Organic Carbon Content ( OC) 1.74% ( HORIZN = 1,2) 0.174 ( HORIZN = 3) NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/)

3. Pennsylvania Corn ( PAcornC)

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.

PRZM 3.12 Scenario Input Parameters for Lancaster County, Pennsylvania  Corn Parameter Value Source Starting Date January 1, 1961 Meteorological File  Allentown, PA ( W14737) Section II. D. 6  Page 66 of 120 Ending Date December 31, 1990 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)

Erosion and Landscape Parameters 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) 464 m Shipman Reservoir ( EPA, 1999) Crop Parameters 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) 30 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 Usual Planting and Harvesting Dates for U. S. Field Crops and Penn. State Coop. Extension Date of Crop Harvest ( HAD, HAM, IYRHAR) 01/ 10 Usual Planting and Harvesting Dates for U. S. Field Crops and Penn. State Coop. Extension Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation Section II. D. 6  Page 67 of 120 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) Hagerstown Soil Parameters Total Soil Depth ( CORED) 100 cm Number of Horizons ( NHORIZ) 3 NRCS, National Soils Characterization Database ( NRCS, 2001)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 40 cm ( HORIZN = 2) 50 cm ( HORIZN = 3) Bulk Density ( BD) 1.6 g cm 3 ( HORIZN = 1) 1.7 g cm 3 ( HORIZN = 2) 1.8 g cm 3 ( HORIZN = 3) Initial Water Content ( THETO) 0.282 cm3 H2O cm3 soil ( HORIZN = 1) 0.2942cm3 H2O cm3 soil ( HORIZN = 2) 0.245 cm3 H2O cm3 soil ( HORIZN = 3) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 5.0 cm ( HORIZN = 2,3) Field Capacity ( THEFC) 0.282 cm3 H2O cm3 soil ( HORIZN = 1) 0.242cm3 H2O cm3 soil ( HORIZN = 2) 0.245 cm3 H2O

cm3 soil ( HORIZN = 3) Wilting Point ( THEWP) 0.122 cm3 H2O cm3 soil ( HORIZN = 1) 0.142 cm3 H2O cm3 soil ( HORIZN = 2) 0.145 cm3 H2O cm3 soil ( HORIZN = 3) Organic Carbon Content ( OC) 2.9% ( HORIZN = 1) 0.174% ( HORIZN = 2) 0.116% ( HORIZN = 3) NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/)

4. Pennsylvania Vegetables ( PAvegetblCRA)

The Pennsylvania Vegetable crop/ field scenario represents the typical potato and pumpkin crop/ field conditions in southeastern Pennsylvania. Potatoes are grown in Pennsylvania from mid July to September and mid September to mid May. Potato seeds are placed 7 to 12 inches apart in rows. Soil is ridged over the seed rows or hilling in order to prevent greening and to control weeds before seedlings bloom. Potatoes are Section II. D. 6  Page 68 of 120 fertilized twice, during planting using a band treatment along side the seedling rows and during cultivation or hilling. Potatoes are typically harvested from mid July to October in Pennsylvania. 80% of the potato crop production occurs in Erie, Cambria, Schuykill, Lancaster, and Potter counties ( IPM, 2004a). Pennsylvania is ranked 2nd in the United States for pumpkin production in the United States, making up 10% of total pumpkin production in the United States. The majority of pumpkin production in Pennsylvania occurs in the southeastern region. Pumpkins are mostly direct seeded with conventional tillage preparation. Pumpkins are grown in silts, gravely loams, and clays. Planting typically occurs between early June and July ( IPM, 2004b).

The Clarksburg soil series was selected to represent the Pennsylvania Vegetable scenario. Clarksburg soils are silt loams, the soil type where potato and pumpkin crops are typically grown. The Clarksburg soil series is a very deep, moderately well drained soil formed in colluvium, glacial till or residuum from limestone, calcareous and noncalcareous shale and sandstone. This soil series is located on uplands with slopes ranging from 0 to 25 percent. Soil permeability is slow to moderately slow. This taxonomic class is described as fine loamy, mixed, super active, mesic Oxyaquic Fragiudalfs. The typical pedon is a silt loam located on a 5 percent northeast facing slope in a cultivated field. The Harrisburg, Pennsylvania weather record is selected to represent meteorological conditions for the Pennsylvania Vegetable scenario. This is the MLRA 148 region ( USDA, 2004).

PRZM 3.12 Scenario Input Parameters for Lancaster County, Pennsylvania  Vegetable Parameter Value Source Starting Date January 1, 1961 Meteorological File  Harrisburg, PA, W14751 Ending Date December 31, 1990 Meteorological File  Harrisburg, PA, W14751 Pan Evaporation Factor ( PFAC) 0.79 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.36 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD) 17.5 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.37 tons EI 1* Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/), Lancaster County, Pennsylvania  Vegetable: Clarksburg silt loam USLE LS Factor ( USLELS) 0.44 Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/), Lancaster County, Pennsylvania  Vegetable: Clarksburg silt loam USLE P Factor ( USLEP) 1 From PRZM Scenario Guidance ( 2004) and ID potato scenario Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA 2004) NRCS Hyetograph ( IREG) 3 PRZM Manual Figure 5.12 ( EPA, 1998) Section II. D. 6  Page 69 of 120 Slope ( SLP) 12.5% NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/), Lancaster County, Pennsylvania  Vegetable: Clarksburg silt loam Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA 2004) Irrigation Flag ( IRFLAG) 0 From PRZM Scenario Guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Leaching Factor ( FLEACH) Not applicable Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops (. EPA 2004) Initial Surface Condition ( ISCOND) 1 PRZM Scenario Guidance ( 2004)

Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological File  Lancaster, PA Maximum rainfall interception storage of crop ( CINTCP) 0.1cm Maximum recommended value for grass ( Carsel et al. 1998)

Maximum Active Root Depth ( AMXDR) 60 cm PRZM Manual ( Carsel et al., 1998)

Maximum Canopy Coverage ( COVMAX) 40% PRZM Manual ( Carsel et al., 1998)

Soil Surface Condition After Harvest ( ICNAH) 3 From ID potato scenario Date of Crop Emergence ( EMD, EMM, IYREM) 10/ 5/ 61 From ID potato scenario Date of Crop Maturity ( MAD, MAM, IYRMAT) 1/ 10/ 61 From ID potato scenario Date of Crop Harvest ( HAD, HAM, IYRHAR) 10/ 10/ 61 From ID potato scenario Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 89, 86, 87 Gleams Manual Table A. 3, Pasture/ Range, Non CNT, Poor ( USDA, 1990) Manning's N Value ( MNGN) .014 RUSLE Project , PA Potato ( Irish), York County, File Code: S65P1PC Section II. D. 6  Page 70 of 120 USLE C Factor ( USLEC) .694 .698 .701 .705 .713 .728 .746 .767 .736 .842 .870 .872 .809 .568 .392 .282 .118 .057 .052 .213 .534 .593 .635 .663 .679 .689 RUSLE Project , PA Potato ( Irish), York County, File Code: SB5P1PC Clarksburg Soil Parameters Total Soil Depth ( CORED) 152 cm Number of Horizons ( NHORIZ) 4 NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 12 cm ( HORIZN = 2) 34 cm ( HORIZN = 3) 96 cm ( HORIZN = 4) Bulk Density ( BD) 1.3 g cm 3 ( HORIZN = 1) 1.3 g cm 3 ( HORIZN = 2) 1.4 g cm 3 ( HORIZN = 3) 1.6 g cm 3 ( HORIZN = 4) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Initial Water Content ( THETO) 0.32cm3 H20 cm3 soil ( HORIZN = 1 4) Field Capacity values, PRZM Scenario Guidance ( 2004) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 2 cm ( HORIZN = 2,3) 4 cm ( HORIZN = 4) PRZM Scenario Guidance ( 2004)

Field Capacity ( THEFC) 0.32 cm3 H20 cm3 soil ( HORZIN = 1 4) GLEAMS Table H 3 ( 1990)

Wilting Point ( THEWP) 0.21 cm3 H20 cm3 soil ( HORZIN = 1 4) GLEAMS Table H 3 ( 1990)

Organic Carbon Content ( OC) 1.8% ( HORIZN = 1) 0.24% ( HORIZN = 2) 0.09% ( HORIZN = 3) 0.09% ( HORIZN = 4) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/); Adjusted using the relationship % OC = 0.6 x % Organic Matter ( Doucette 2000)

5. Illinois Corn ( ILcornC)

The field used to represent corn production in Illinois is located in McLean County, although the crop is grown extensively throughout the state. According to the 1997 Census of Agriculture, Illinois is ranked 2nd among the major corn producing states in the U. S. The crop is generally planted the early Spring ( April) in the south, early May in the north and harvested beginning in August. Continuous corn is practice is much of the region ( approximately 30 percent is continuous), however, rotation with other crops such as soybean, wheat, sorghum, and alfalfa is the dominant practice. Most of the corn is planted for feed grain, but may also be planted for oil, sweetener, and for export. Planting depth and row spacing ( generally 30 inches) follows general practices for the U. S. Conservation tillage practices are regularly used for field corn with no_ till practiced on about 20 percent of the corn acreage annually. About 50 percent of the acreage is cultivated with a row cultivator and an estimated 40 percent is rotary hoed annually. The crop is rarely grown under irrigation. The soil selected to simulate the field is an Adair clan loam. Adair clay loam is a fine, smectitic, mesic Aquertic Argiudolls. More than 50 percent of the soil is used for the production of grains with the balance in meadow and Section II. D. 6  Page 71 of 120 pasture. Adair clay loam is a deep, somewhat poorly drained, medium to rapid runoff, slowly permeable soil formed on uplands in a thin mantle of loess or loess and pedisediments and a paleosol formed in glacial till. They are on convex summits of narrow interfluves and on convex side slopes at slightly lower elevations. Slopes are generally between 2 to 18 percent, but may range to 30 percent. The soils are extensive in MLRA 108 and found in many MLRA in the region. Adair clay loam is a Hydrologic Group C soil.

PRZM 3.12 Scenario Input Parameters for McLean County, Illinois  Corn Parameter Value Source Starting Date January 1, 1961 Meteorological File   Peoria, IL ( W14842) Ending Date December 31, 1990 Meteorological File   Peoria, IL ( W14842) Pan Evaporation Factor ( PFAC) 0.77 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.36 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD) 16.0 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.32 tons EI 1* GLEAMS Table of Representative Soils ( USDA, 1990) USLE LS Factor ( USLELS) 1.126 GLEAMS Table of Representative Soils ( USDA, 1990) USLE P Factor ( USLEP) 1.00 PRZM Manual ( 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) 6% Selected according to QA/ QC Guidance ( EPA, 2001) Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Initial Surface Condition ( ISCOND) 3 PRZM Input Collator ( Burns, 1992); Lyle Paul of U of Illinois indicates residues are typically chiseled in Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological File   Peoria, IL ( W14842) Maximum rainfall interception storage of crop ( CINTCP) 0.25 Maximum recommended value for grass Maximum Active Root Depth ( AMXDR) 90 cm PRZM Input Collator ( Burns, 1992) Section II. D. 6  Page 72 of 120 Maximum Canopy Coverage ( COVMAX) 100 PRZM Input Collator ( Burns, 1992); Lyle Paul of U of Illinois Soil Surface Condition After Harvest ( ICNAH) 3 PRZM Input Collator ( Burns, 1992); Lyle Paul of U of Illinois Date of Crop Emergence ( EMD, EMM, IYREM) 01/ 05 Date of Crop Maturity ( MAD, MAM, IYRMAT) 21/ 09 Date of Crop Harvest ( HAD, HAM, IYRHAR) 20/ 10 Usual Planting and Harvest Dates for US Field Crops ( USDA, 1984) & Updated Crop Stage Information from HED ( Bernard Schneider)

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 = SR/ poor; Cropping and Residue = Row Crop, SR/ poor condition ( USDA, 1990) Manning's N Value ( MNGN) 0.014 RUSLE Project, MA3CGSBC; Corn, grain, Conventional tillage, Springfield, IL ( USDA, 2000) USLE C Factor ( USLEC) 0.017  0.638 RUSLE Project; MA3CGSBC; Corn, grain, Conventional tillage, Springfield, IL, variable with date ( USDA, 2000) Adair Soil Parameters Total Soil Depth ( CORED) 100 cm Number of Horizons ( NHORIZ) 4 ( Top horizon split in two) PIC ( Burns, 1992) Confirmed with: NRCS, National Soils Characterization Database ( NRCS, 2001)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 34 cm ( HORIZN = 2) 44 cm ( HORIZN = 3) 12 cm ( HORIZN = 4) Bulk Density ( BD) 1.5 g cm 3 ( HORIZN = 1, 2) 1.6 g cm 3 ( HORIZN = 3) 1.7 g cm 3 ( HORIZN = 4) Initial Water Content ( THETO) 0.355 cm3 H2O cm3 soil ( HORIZN = 1, 2) 0.338 cm3 H2O cm3 soil ( HORIZN = 3) 0.307 cm3 H2O cm3 soil ( HORIZN = 4) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 2 cm ( HORIZN = 2,3,4) Field Capacity ( THEFC) 0.355 cm3 H2O cm3 soil ( HORIZN = 1, 2) 0.338 cm3 H2O cm3 soil ( HORIZN = 3) 0.307 cm3 H2O cm3 soil ( HORIZN = 4) PIC ( Burns, 1992) Confirmed with: NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/) Section II. D. 6  Page 73 of 120 Wilting Point ( THEWP) 0.185 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.208 cm3 H2O cm3 soil ( HORIZN = 3) 0.167 cm3 H2O cm3 soil ( HORIZN = 4) Organic Carbon Content ( OC) 2.32% ( HORIZN = 1,2) 0.174% ( HORIZN = 3) 0.116% ( HORIZN = 4)

6. Illinois Alfalfa ( ILalfalfaCRA)

Alfalfa production in Illinois represents 2.2% of the alfalfa production in the United States. Alfalfa is harvested in late May to mid June with successive cuttings occurring every 28 to 34 days until September or October ( IPM, 2004). The Varna soil series was selected to represent the Illinois Alfalfa crop scenario. This soil type is a silt loam with the largest spatial extent in McLean County, Illinois, the region selected to represent alfalfa production in Illinois. The Varna soil is very deep, moderately well drained, slowly permeable soil located on till plains. It is a fine, illitic, mesic Oxyaquic Argiudolls soil. The typical pedon is located on a northwest facing convex slope of 3 percent at an elevation of 722 feet. The weather record from Peoria, Illinois located in the MLRA region of 108 ( USDA 2004).

PRZM 3.12 Scenario Input Parameters for McLean County, Illinois  Alfalfa Parameter Value Source Starting Date January 1, 1961 Meteorological File  Peoria, Illinois ( W14842) Ending Date December 31, 1990 Meteorological File  Peoria, Illinois ( W14842) Pan Evaporation Factor ( PFAC) 0.76 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.36 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD) 17.5 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.28 tons EI 1* Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/), McLean County, Illinois: Varna Silt Loam USLE LS Factor ( USLELS) 0.44 PRZM Manual, Table 5 5 ( EPA 1998), Default slope length = 400 ft. USLE P Factor ( USLEP) 1 From PRZM Scenario Guidance ( 2004)

Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA 2004) NRCS Hyetograph ( IREG) 3 PRZM Manual Figure 5.12 ( EPA, 1998) Section II. D. 6  Page 74 of 120 Slope ( SLP) 3 NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/), McLean County, Illinois: Varna Silt Loam Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA 2004) Irrigation Flag ( IRFLAG) 0 From PRZM Scenario Guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Leaching Factor ( FLEACH) Not applicable Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops (. EPA 2004) Initial Surface Condition ( ISCOND) 1 PRZM Scenario Guidance ( EPA, 2004)

Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological File  Peoria, Illinois ( W14842) Maximum rainfall interception storage of crop ( CINTCP) 0.25 cm Maximum recommended value for grass ( Carsel 1998)

Maximum Active Root Depth ( AMXDR) 100 cm Taken from Minnesota Alfalfa scenario Maximum Canopy Coverage ( COVMAX) 100% Taken from Minnesota Alfalfa scenario Soil Surface Condition After Harvest ( ICNAH) 3 Taken from Minnesota Alfalfa scenario Date of Crop Emergence ( EMD, EMM, IYREM) 1/ 6/ 61 Taken from Minnesota Alfalfa scenario Date of Crop Maturity ( MAD, MAM, IYRMAT) 25/ 8/ 61 Taken from Minnesota Alfalfa scenario Date of Crop Harvest ( HAD, HAM, IYRHAR) 30/ 8/ 61 Taken from Minnesota Alfalfa scenario Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 82, 85, 87 Gleams Manual Table H 4, Close seeded legumes or rotation meadow, straight row, poor ( USDA, 1990) Section II. D. 6  Page 75 of 120 Manning's N Value ( MNGN) .110 . RUSLE Project, File Code: MA5HLHLC ( Carbondale, IL, Hay legume)

USLE C Factor ( USLEC) .015 .015 .015 .016 .016 .018 .012 .006 .002 .007 .004 .002 .007 .006 .003 .001 .005 .003 .003 .005 .009 .013 .014 .014 .015 .015 RUSLE Project, File Code: MA5HLHLC ( Carbondale, IL, Hay legume)

Varna Soil Parameters Total Soil Depth ( CORED) 152 cm Number of Horizons ( NHORIZ) 5 ( top horizon split in 2) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 20 cm ( HORIZN = 2) 38 cm ( HORIZN = 3) 31 cm ( HORIZN = 4) 53 cm ( HORIZN = 5) Bulk Density ( BD) 1.5 g cm 3 ( HORIZN = 1) 1.5 g cm 3 ( HORIZN = 2) 1.45 g cm 3 ( HORIZN = 3) 1.6 g cm 3 ( HORIZN = 4) 1.8 g cm 3 ( HORIZN = 5) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Initial Water Content ( THETO) 0.32 cm3 H20 cm3 soil ( HORIZN = 1  5) Field Capacity values, PRZM Scenario Guidance ( 2004) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 1 cm ( HORIZN = 2,3,4,5) PRZM Scenario Guidance ( 2004)

Field Capacity ( THEFC) 0.32 cm3 H20 cm3 soil ( HORIZN = 1  5) GLEAMS Table H 3 ( 1990) ( Silt loam) Wilting Point ( THEWP) 0.12 cm3 H20 cm3 soil ( HORIZN = 1  5) GLEAMS Table H 3 ( 1990) ( Silt loam)

Organic Carbon Content ( OC) 1.5% ( HORIZN = 1) 1.5% ( HORIZN = 2) 0.6% ( HORIZN = 3) 0.18% ( HORIZN = 4) 0.15% ( HORIZN = 5) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/); Adjusted using the relationship % OC = 0.6 x % Organic Matter ( Doucette 2000)

7. Illinois Beans ( ILbeanCRA)

The Illinois Bean scenario represents the environmental conditions for snap bean, green pea, and lima bean production in Illinois. Lima beans are typically planted in June or July after a pea crop. Lima beans may be planted between May and July ( IPM, 2004 a). Snap bean seedlings are started in the greenhouse in March and April, then transplanted to the field in June. Snap beans prefer well drained soils and a soil pH ranging from 5.5 to 6.0. Snap beans are planted 3/ 4 to 1 inch deep at the end of the frost season for harvest in the spring. Snap beans may also be planted in early summer for harvest in late fall before the first frost. Snap bean seedlings are planted in rows 2 inches wide with 18 to 36 inches between the rows ( IPM, 2004 b). Green peas are planted in Section II. D. 6  Page 76 of 120 rows 6 to 7 inches apart. Planting occurs in early spring. Green peas must be harvested prior to hot, dry weather of mid to late summer ( IPM, 2004 c). The Varna soil series was selected to represent the Illinois Beans crop scenario. This soil type is a silt loam with the largest spatial extent in McLean County, Illinois, the region selected to represent bean production in Illinois. The Varna soil is very deep, moderately well drained, slowly permeable and located on till plains. It is a fine, illitic, mesic Oxyaquic Argiudolls soil. The typical pedon is located on a northwest facing convex slope of 3 percent at an elevation of 722 feet. The weather record from Peoria, Illinois is located in the MLRA region of 108 ( USDA, 2004).

PRZM 3.12 Scenario Input Parameters for McLean County, Illinois  Beans Parameter Value Source Starting Date January 1, 1961 Meteorological File  Peoria, Illinois ( W14842) Ending Date December 31, 1990 Meteorological File  Peoria, Illinois ( W14842) Pan Evaporation Factor ( PFAC) 0.76 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.36 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998) Minimum Depth of Evaporation ( ANETD) 17.5 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.28 tons EI 1* Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/), McLean County, Illinois: Varna Silt Loam USLE LS Factor ( USLELS) 0.44 PRZM Manual, Table 5 5 ( EPA 1998), Default slope length = 400 ft. USLE P Factor ( USLEP) 1 From PRZM Scenario Guidance ( 2004)

Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA 2004) NRCS Hyetograph ( IREG) 3 PRZM Manual Figure 5.12 ( EPA, 1998)

Slope ( SLP) 3 NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/), McLean County, Illinois: Varna Silt Loam Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA 2004) Irrigation Flag ( IRFLAG) 0 From PRZM Scenario Guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Leaching Factor ( FLEACH) Not applicable Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Crop Parameters Section II. D. 6  Page 77 of 120 Initial Crop ( INICRP) 1 Set to one for all crops (. EPA 2004) Initial Surface Condition ( ISCOND) 1 PRZM Scenario Guidance ( 2004)

Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological File  Peoria, Illinois ( W14842) Maximum rainfall interception storage of crop ( CINTCP) 0.1 cm Taken from Oregon Snapbeans scenario Maximum Active Root Depth ( AMXDR) 18 cm Taken from Oregon Snapbeans scenario Maximum Canopy Coverage ( COVMAX) 80% Taken from Oregon Snapbeans scenario Soil Surface Condition After Harvest ( ICNAH) 1 Taken from Oregon Snapbeans scenario Date of Crop Emergence ( EMD, EMM, IYREM) 16/ 6/ 61 Taken from Oregon Snapbeans scenario Date of Crop Maturity ( MAD, MAM, IYRMAT) 18/ 8/ 61 Taken from Oregon Snapbeans scenario Date of Crop Harvest ( HAD, HAM, IYRHAR) 2/ 9/ 61 Taken from Oregon Snapbeans scenario Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 92, 89, 90 Gleams Manual Table H 4, Close seeded legumes, fallow, ST/ CT, poor ( USDA, 1990) Manning's N Value ( MNGN) .023 RUSLE Project, File Code: MaISBCGC Chicago, IL, Soybean USLE C Factor ( USLEC) .086 .089 .092 .095 .100 .109 .124 .145 .168 .278 .292 .342 .372 .395 .381 .326 .199 .067 .072 .054 .073 .093 .046 .047 .193 .219 .242 .258 .270 RUSLE Project, File Code: MaISBCGC Chicago, IL, Soybean Varna Soil Parameters Total Soil Depth ( CORED) 152 cm Number of Horizons ( NHORIZ) 5 ( top horizon split in 2) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 20 cm ( HORIZN = 2) 38 cm ( HORIZN = 3) 31 cm ( HORIZN = 4) 53 cm ( HORIZN = 5) Bulk Density ( BD) 1.5 g cm 3 ( HORIZN = 1) 1.5 g cm 3 ( HORIZN = 2) 1.45 g cm 3 ( HORIZN = 3) 1.6 g cm 3 ( HORIZN = 4) 1.8 g cm 3 ( HORIZN = 5) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Initial Water Content ( THETO) 0.32 cm3 H20 cm3 soil ( HORIZN = 1  5) Field Capacity values, PRZM Scenario Guidance ( 2004) Section II. D. 6  Page 78 of 120 Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 1 cm ( HORIZN = 2,3,4,5) PRZM Scenario Guidance ( 2004)

Field Capacity ( THEFC) 0.32 cm3 H20 cm3 soil ( HORIZN = 1  5) GLEAMS Table H 3 ( 1990) ( Silt loam) Wilting Point ( THEWP) 0.12 cm3 H20 cm3 soil ( HORIZN = 1  5) GLEAMS Table H 3 ( 1990) ( Silt loam) Organic Carbon Content ( OC) 1.5% ( HORIZN = 1) 1.5% ( HORIZN = 2) 0.6% ( HORIZN = 3)

0.18% ( HORIZN = 4) 0.15% ( HORIZN = 5) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/); Adjusted using the relationship % OC = 0.6 x % Organic Matter ( Doucette 2000) Section II. D. 6  Page 79 of 120 I. Northern Great Plains Region Scenario Documentation 1. Minnesota Potatoes ( MNpotatoCRA)

The field used to represent potato production in Minnesota is located in Polk County, in the Red River Valley. However, the scenario should be considered as representative of the major potato producing region of the Red River Valley, which included counties in both Minnesota and North Dakota. According to the USDA Crop Profile for Potatoes in Minnesota ( USDA, 2002), Minnesota ranked 7th nationally in potato production, with the largest producing regions in the northwest ( Polk, Clay, Kittson, Marshall, and Red Lake counties) and the central ( Sherburne, Morrison, Todd counties). Because this scenario is being developed for the N methyl carbamate cumulative risk assessment, a scenario site in the northwest ( Red River Valley) was selected to coincide with the regional cumulative assessment area. The site may still be of value as a regional potato scenario since it does represent an area of the country with relatively high potato production ( North Dakota, on the other side of the Red River, is 6th in potato production, with the main producing area in ND being the Red River Valley [ USDA, 2000b]). The Red River Valley MLRA ( 56) includes the North Dakota counties along the eastern border ( Pembina, Walsh, Grand Forks, Traill, Cass, and Richland) and the Minnesota counties along the northwestern border ( Kittson, Marshall, Polk, Pennington, Red Lake, Norman, Clay, Wilkin, and Traverse).

Planting begins in late April ( after soil temperatures reach 45oF) through the end of May. Potatoes are harvested roughly 90 days after planting, beginning in late August and continuing through October ( USDA, 2002). Row spacing is generally 32 to 36 inches, with rows 8 16 inches apart. Potatoes are generally grown once every three years on the same field to limit disease pressures ( Willem Schrage, Minnesota Dept. of Agriculture). While a " significant portion" of MN potato acres are irrigated ( USDA, 2002), irrigation generally occurs on coarse textured ( sandy loams or loamy sands) soils low in organic matter ( USDA, 2000b). Potatoes and sugar beets may be grown on the same soils, but do not follow each other in a rotation because of the depletion of moisture ( USDA, 2000b).

While the ideal potato soils are sandy loam textured, fertile fine to mediumtextured soils are also appropriate for potato production ( USDA, 2002). The soil selected to simulate the field is a benchmark soil, Bearden silty clay loam. This is the same soil used for the sugar beet scenario. Bearden silty clay loam, is a fine silty, mixed, superactive, frigid Aeric Calciaquolls. These soils are nearly all under cultivation to small grains, especially alfalfa, and row crops ( i. e., sugar beets). Bearden silty clay loam is a very deep, somewhat poorly drained, slowly permeable soil with negligible to high runoff. A seasonal high water table is at depths of 1.5 to 3.5 feet as some time during the period of April to June. These soils formed in calcareous silt loam and silty clay loam lacustrine sediments. They are generally found on glacial lake plains at elevations from 650 to 2000 feet above mean sea level on slopes of 0 to 3 percent. Bearden silty clay loam is a Hydrologic Group C soil. The series is of large extent in Minnesota, North Dakota, and South Dakota. Section II. D. 6  Page 80 of 120 PRZM 3.12 Scenario Input Parameters for Polk County, Minnesota   Potatoes Parameter Value Source Starting Date January 1, 1961 Meteorological File   Fargo, ND ( W14914) Ending Date December 31, 1990 Meteorological File  Fargo, ND ( W14914) Pan Evaporation Factor ( PFAC) 0.75 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.50 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD) 12.0 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.28 tons EI 1* GLEAMS Table of Representative Soils ( USDA, 1990)

USLE LS Factor ( USLELS) 0.17 GLEAMS Table of Representative Soils ( USDA, 1990)

USLE P Factor ( USLEP) 0.5 PRZM Manual ( 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) 1.5% Selected according to QA/ QC Guidance ( EPA, 2001) Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Initial Surface Condition ( ISCOND) 1 PRZM Input Collator ( Burns, 1992)

Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological File   Fargo, ND ( W14914) Maximum rainfall interception storage of crop ( CINTCP) 0.1 PRZM Table 5.4 ( EPA, 1998)

Maximum Active Root Depth ( AMXDR) 60 cm http:// www. css. orst. edu/ Classes/ CSS322/ Growing. htm Maximum Canopy Coverage ( COVMAX) 100 PRZM Input Collator ( Burns, 1992); Dr. Mohamed Kahn; NDSU ( 701) 231_ 8596; Larry Smith U of MN ( 218) 281_ 8602. Soil Surface Condition After Harvest ( ICNAH) 3 PRZM Input Collator, PIC ( Burns, 1992)

Date of Crop Emergence ( EMD, EMM, IYREM) 15/ 05 Date of Crop Maturity ( MAD, MAM, IYRMAT) 06/ 09 Based on beginning of most active planting dates ( May 8   May 31) and harvest dates ( Sep 16   Oct 12) for potatoes in MN, adding 7 days for emergence and 10 days between maturity & harvest ( USDA 1997) Section II. D. 6  Page 81 of 120 Date of Crop Harvest ( HAD, HAM, IYRHAR) 15/ 09 Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 91, 85, 87 Gleams Manual Table A. 3, Fallow = SR/ poor; Cropping and Residue = Row Crop, SR/ poor condition ( USDA, 1990) Manning's N Value ( MNGN) 0.014 RUSLE Project: F86PIPIC   Potatoes, Conventional tillage, Fargo, ND ( USDA, 2000a) USLE C Factor ( USLEC) .649 .774 .808 .816 .740 .441 .349 .233 .055 .056 .050 .496 .530 .565 .581 .588 .587 .586 .584 .583 .581 .579 .577 .580 .590 .612 .638 .639 RUSLE Project: F86PIPIC   Potatoes, Conventional tillage, Fargo, ND ( USDA, 2000a). Order of C factors revised to follow crop emergence sequence ( May 16   1605   is the beginning date)

Bearden Soil Parameters Total Soil Depth ( CORED) 100 cm Number of Horizons ( NHORIZ) 4 ( 3 Base, Top horizon split in two) PIC ( Burns, 1992) Confirmed with: NRCS, National Soils Characterization Database ( NRCS, 2001)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 8 cm ( HORIZN = 2) 54 cm ( HORIZN = 3) 28 cm ( HORIZN = 4) Bulk Density ( BD) 1.4 g cm 3 ( HORIZN 1, 2) 1.5 g cm 3 ( HORIZN 3) 1.8 g cm 3 ( HORIZN 4) Initial Water Content ( THETO) 0.377 cm3 H2O cm3 soil ( HORIZN 1, 2) 0.292 cm3 H2O cm3 soil ( HORIZN 3) 0.285 cm3 H2O cm3 soil ( HORIZN 4) Compartment Thickness ( DPN) 0.1 cm ( HORIZN 1) 2.0 cm ( HORIZN 2,3,4) Field Capacity ( THEFC) 0.377 cm3 H2O cm3 soil ( HORIZN 1, 2) 0.292 cm3 H2O cm3 soil ( HORIZN 3) 0.285 cm3 H2O cm3 soil ( HORIZN 4) Wilting Point ( THEWP) 0.207 cm3 H2O cm3 soil ( HORIZN 1,2) 0.132 cm3 H2O cm3 soil ( HORIZN 3) 0.125 cm3 H2O cm3 soil ( HORIZN 4) PIC ( Burns, 1992) Confirmed with: NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/) NOTE: Used same soil parameters as used for MN Sugar Beets scenario since the scenarios are based on the same benchmark soil Section II. D. 6  Page 82 of 120 Organic Carbon Content ( OC) 4.06% ( HORIZN = 1,2) 0.174% ( HORIZN = 3) 0.116% ( HORIZN = 4)

2. Minnesota Sugar Beets ( MNsugarbeetC)

The field used to represent sugar beet production in Minnesota is located in Polk County, in the Red River Valley ( MLRA 56). According to the 1997 Census of Agriculture, Minnesota ranked 1st in production and acreage of sugar beets in the U. S. The crop is generally planted the late spring and harvested beginning in October. Row spacing is generally 30 inches. Row canopies tend to be very close to 100 percent, while the canopy between rows is much less. The crop may be grown under irrigation by furrow, canal, or center pivot systems. However, sugar beets grown in the Red River Valley do not need to be irrigated.

The soil selected to simulate the field is a benchmark soil, Bearden silty clay loam. Bearden silty clay loam, is a fine silty, mixed, superactive, frigid Aeric Calciaquolls. These soils are nearly all under cultivation to small grains, especially alfalfa, and row crops ( i. e., sugar beets). Bearden silty clay loam is a very deep, somewhat poorly drained, slowly permeable soil with negligible to high runoff. A seasonal high water table is at depths of 1.5 to 3.5 feet as some time during the period of April to June. These soils formed in calcareous silt loam and silty clay loam lacustrine sediments. They are generally found on glacial lake plains at elevations from 650 to 2000 feet above mean sea level on slopes of 0 to 3 percent. Bearden silty clay loam is a Hydrologic Group C soil. The series is of large extent in Minnesota, North Dakota, and South Dakota.

PRZM 3.12 Scenario Input Parameters for Polk County, Minnesota  Sugar Beets Parameter Value Source Starting Date January 1, 1961 Meteorological File  Fargo, ND ( W14914) Ending Date December 31, 1990 Meteorological File  Fargo, ND ( W14914) Pan Evaporation Factor ( PFAC) 0.75 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.50 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998) Minimum Depth of Evaporation ( ANETD) 12.0 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.28 tons EI 1* GLEAMS Table of Representative Soils ( USDA, 1990) USLE LS Factor ( USLELS) 0.17 GLEAMS Table of Representative Soils ( USDA, 1990) USLE P Factor ( USLEP) 0.5 PRZM Manual ( EPA, 1998)

Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA, 1999) Section II. D. 6  Page 83 of 120 NRCS Hyetograph ( IREG) 3 PRZM Manual Figure 5.12 ( EPA, 1998)

Slope ( SLP) 1.5% Selected according to QA/ QC Guidance ( EPA, 2001) Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Initial Surface Condition ( ISCOND) 1 PRZM Input Collator ( Burns, 1992)

Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological File  Fargo, ND ( W14914) Maximum rainfall interception storage of crop ( CINTCP) 0.2 PRZM Table 5.4 ( EPA, 1998)

Maximum Active Root Depth ( AMXDR) 100 cm Set to soil profile depth. Roots can be as much as 8 feet deep. Dr. Mohamed Kahn; NDSU ( 701) 231_ 8596; Larry Smith U of MN ( 218) 281_ 8602. Maximum Canopy Coverage ( COVMAX) 100 PRZM Input Collator ( Burns, 1992); Dr. Mohamed Kahn; NDSU ( 701) 231_ 8596; Larry Smith U of MN ( 218) 281_ 8602. Soil Surface Condition After Harvest ( ICNAH) 3 PRZM Input Collator, PIC ( Burns, 1992)

Date of Crop Emergence ( EMD, EMM, IYREM) 11/ 05 Date of Crop Maturity ( MAD, MAM, IYRMAT) 01/ 10 Date of Crop Harvest ( HAD, HAM, IYRHAR) 15/ 10 Usual Planting and Harvest Dates for US Field Crops ( USDA, 1984) & Updated Crop Stage Information from HED ( Bernard Schneider)

Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 91, 85, 87 Gleams Manual Table A. 3, Fallow = SR/ poor; Cropping and Residue = Row Crop, SR/ poor condition ( USDA, 1990) Manning's N Value ( MNGN) 0.014 RUSLE Project, F86SUSUC); Sugar beets, Conventional tillage, Fargo, ND ( USDA, 2000) USLE C Factor ( USLEC) 0.017  0.638 RUSLE Project; F86SUSUC); Sugar beets, Conventional tillage, Fargo, ND ( USDA, 2000) Soil Parameters  Bearden Total Soil Depth ( CORED) 100 cm Number of Horizons ( NHORIZ) 4 ( 3 Base, Top horizon split in two) NRCS, National Soils Characterization Database ( NRCS, 2001)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 8 cm ( HORIZN = 2) 54 cm ( HORIZN = 3) 28 cm ( HORIZN = 4) NRCS, National Soils Characterization Database ( NRCS, 2001) Section II. D. 6  Page 84 of 120 Bulk Density ( BD) 1.4 g cm 3 ( HORIZN = 1, 2) 1.5 g cm 3 ( HORIZN = 3) 1.8 g cm 3 ( HORIZN = 4) Initial Water Content ( THETO) 0.377 cm3 H2O cm3 soil ( HORIZN = 1, 2) 0.292 cm3 H2O cm3 soil ( HORIZN = 3) 0.285 cm3 H2O cm3 soil ( HORIZN = 4) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 2.0 cm ( HORIZN = 2,3,4) Field Capacity ( THEFC) 0.377 cm3 H2O cm3 soil ( HORIZN = 1, 2) 0.292 cm3 H2O cm3 soil ( HORIZN = 3) 0.285 cm3 H2O cm3 soil ( HORIZN = 4) Wilting Point ( THEWP) 0.207 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.132 cm3 H2O cm3 soil ( HORIZN = 3) 0.125 cm3 H2O cm3 soil ( HORIZN = 4) Organic Carbon Content ( OC) 4.06% ( HORIZN = 1,2) 0.174% ( HORIZN = 3) 0.116% ( HORIZN = 4)

3. North Dakota Wheat ( NDwheatC)

The field used to represent wheat production in North Dakota is located in Cass County in the Red River Valley. According to the 1997 Census of Agriculture, North Dakota is ranked 1st in the production of both durum and spring wheat in the U. S. The crop is generally planted in the Spring ( late April to the end of May) and harvested beginning in August. Continuous wheat is practice is much of the region. Conventional tillage is used but requires greater seedbed preparation. No till and reduced tillage systems are designed for use in high residue conditions. Row spacing ranges from 6 to 9 inches with seeds planted at a depth of 2 inches or less. The soil selected to simulate the field is a benchmark soil, Bearden silty clay loam. Bearden silty clay loam, is a fine silty, mixed, superactive, frigid Aeric Calciaquolls. These soils are nearly all under cultivation to small grains, especially alfalfa, and row crops. Bearden silty clay loam is a very deep, somewhat poorly drained, slowly permeable soil with negligible to high runoff. These soils formed in calcareous silt loam and silty clay loam lacustrine sediments. They are generally found on glacial lake plains at elevations from 650 to 2000 feet above mean sea level on slopes of 0 to 3 percent. Bearden silty clay loam is a Hydrologic Group C soil.

PRZM 3.12 Scenario Input Parameters for Cass County, North Dakota Wheat Parameter Value Source Section II. D. 6  Page 85 of 120 Starting Date January 1, 1961 Meteorological File  Fargo, ND ( W14914) Ending Date December 31, 1990 Meteorological File  Fargo, ND ( W14914) Pan Evaporation Factor ( PFAC) 0.75 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.5m C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD) 12.0 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.28 tons EI 1* GLEAMS Manual, table of Representative Soils ( USDA, 1990) USLE LS Factor ( USLELS) 0.17 GLEAMS Manual, table of Representative Soils ( USDA, 1990) 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) 3 PRZM Manual Figure 5.12 ( EPA, 1998)

Slope ( SLP) 1.5% Value mid point of series slope range ( EPA, 2001) Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Initial Surface Condition ( ISCOND) 1 Set to fallow prior to new crop planting Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Fargo, ND ( W14914)

Maximum rainfall interception storage of crop ( CINTCP) 0.1 PRZM, Table 5.4 ( EPA, 1998)

Maximum Active Root Depth ( AMXDR) 22 cm PRZM Manual, Table 5.9 ( EPA, 1998)

Maximum Canopy Coverage ( COVMAX) 100 QA/ QC Guidance ( EPA, 2001)

Soil Surface Condition After Harvest ( ICNAH) 1 Fallow conditions after harvest in preparation for winter crop Date of Crop Emergence ( EMD, EMM, IYREM) 15/ 05 Planting and Harvesting dates for spring wheat adjusted for "" C"" value planting and harvesting date ( USDA, 1984) Date of Crop Maturity ( MAD, MAM, IYRMAT) 25/ 07 Planting and Harvesting dates for spring wheat adjusted for "" C"" value planting and harvesting date ( USDA, 1984) Date of Crop Harvest ( HAD, HAM, IYRHAR) 08/ 08 Planting and Harvesting dates for spring wheat adjusted for "" C"" value planting and harvesting date ( USDA, 1984) Section II. D. 6  Page 86 of 120 Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 91, 85, 87 Gleams Manual Table A. 3, Fallow = SR/ CT poor; Cropping = Row Crop SR/ CT poor ( second number; Fallow = row crop SR/ CT poor ( 3rd number) ( USDA, 1990) Manning's N Value ( MNGN) 0.014 RUSLE Project, F86WSFA Fargo, ND spring wheat, fallow, conventional tillage ( USDA, 2000) USLE C Factor ( USLEC) 0.036  0.617 RUSLE Project; F86WSFA Fargo, ND spring wheat, fallow, conventional tillage ( USDA, 2000) Bearden Soil Parameters Total Soil Depth ( CORED) 100 cm Number of Horizons ( NHORIZ) 4 NRCS, National Soils Characterization Database ( NRCS, 2001)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 8 cm ( HORIZN = 2) 54 cm ( HORIZN = 3) 28 cm ( HORIZN = 4) Bulk Density ( BD) 1.4 g cm 3 ( HORIZN = 1,2) 1.5 g cm 3 ( HORIZN = 3) 1.8 g cm 3 ( HORIZN = 4) Initial Water Content ( THETO) 0.377 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.292 cm3 H2O cm3 soil ( HORIZN = 3) 0.285 cm3 H2O cm3 soil ( HORIZN = 4) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 2.0 cm ( HORIZN = 2,3,4) Field Capacity ( THEFC) 0.377 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.292cm3 H2O cm3 soil ( HORIZN = 3) 0.285 cm3 H2O cm3 soil ( HORIZN = 4) Wilting Point ( THEWP) 0.207 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.132 cm3 H2O cm3 soil ( HORIZN = 3) 0.125 cm3 H2O cm3 soil ( HORIZN = 4) Organic Carbon Content ( OC) 1.74% ( HORIZN = 1,2) 0.116% ( HORIZN = 3) 0.058% ( HORIZN = 4) NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/) Section II. D. 6  Page 87 of 120 J. Northwest / WA 1. Washington Apples ( WAorchardsCRA)

The field used to represent orchard production in Central Washington is representative of a field in Grant county, located in the Columbia Basin. The meteorological file, Yakima, WA represents the MLRA region 7, 8. Washington produces 53 percent of U. S. apples, ranking first in the U. S. Apple production in the state of Washington occurs primarily in three regions: Yakima Basin, North Central, and Columbia Basin. Various types of apples, including red delicious, golden delicious, pink lady, granny smith, and more are grown in orchards in Washington ( NSF 2001). Taunton silt loam chosen from Grant county. This soil was chosen over the Scoon silt loam even though more orchard crops are grown in the Scoon soil, since data are available for deeper depths. This is appropriate due to the large maximum rooting depth of apples and cherry trees. Taunton silt loam is a hydrologic group C soil that is classified as coarseloamy mixed, superactive, mesic xeric Haplodurids. The Taunton series of soils is moderately deep to duripan, well drained soils formed in alluvium. These soils occur on terraces and basalt plains, fan terraces and mesas with slopes of 0 to 45 percent. This soil type occurs in South central Washington, north central Oregon and Southern Idaho where it is used for livestock grazing and irrigated crop production ( USDA 2001).

PRZM 3.12 Scenario Input Parameters for Grant County, Washington  Orchard Parameter Value Source Starting Date January 1, 1961 Meteorological File  Yakima, Grant County, Washington Ending Date December 31, 1990 Meteorological File  Yakima, Grant County, Washington Pan Evaporation Factor ( PFAC) 0.71 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.20 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD) 17 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.55 tons EI 1* Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) USLE LS Factor ( USLELS) 0.70 Based on slope taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) , PRZM manual length 400 m, 4% slope USLE P Factor ( USLEP) 1.0 PRZM Manual Table 5.6 ( EPA, 1998)

Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA 2004) NRCS Hyetograph ( IREG) 3 PRZM Manual Figure 5.12 ( EPA, 1998) Section II. D. 6  Page 88 of 120 Slope ( SLP) 3.5% Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Hydraulic Length ( HL) 464 ( reservoir) Shipman Reservoir ( EPA 2004) Irrigation Flag ( IRFLAG) 0 From PRZM Scenario Guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Leaching Factor ( FLEACH) Not applicable Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops (. EPA 2004) Initial Surface Condition ( ISCOND) 3 Consulted extension agent, crops are rotated Number of Different Crops ( NDC) 1 Based on OR apple scenario.

Number of Cropping Periods ( NCPDS) 30 Set to weather data.

Maximum rainfall interception storage of crop ( CINTCP) 0.25 cm Based on OR apple scenario.

Maximum Active Root Depth ( AMXDR) 45 cm Based on OR apple scenario.

Maximum Canopy Coverage ( COVMAX) 98% Based on OR apple scenario.

Soil Surface Condition After Harvest ( ICNAH) 3 Based on OR apple scenario.

Date of Crop Emergence ( EMD, EMM, IYREM) 1/ 5/ 61 Based on OR apple scenario.

Date of Crop Maturity ( MAD, MAM, IYRMAT) 31/ 5/ 61 Based on OR apple scenario.

Date of Crop Harvest ( HAD, HAM, IYRHAR) 7/ 11/ 61 Based on OR apple scenario.

Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 79, 82, 84 Gleams Manual Table A. 3, ( Hydrological soil C) ( USDA, 1990) Manning's N Value ( MNGN) .040 . RUSLE Project ( B060FOFN. dat) Section II. D. 6  Page 89 of 120 USLE C Factor ( USLEC) .004 .005 .006 .006 .009 .010 .011 .011 .011 .010 .009 .008 .006 .005 .005 .005 .005 .005 .005 .005 .002 .003 .003 .003 RUSLE Project ( B060FOFN. dat)

Soil Parameters Total Soil Depth ( CORED) 68 cm NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Number of Horizons ( NHORIZ) 4 NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 10 cm ( HORIZN = 2) 28 cm ( HORIZN = 3) 20 cm ( HORIZN = 4) Bulk Density ( BD) 1.25 g cm 3 ( HORIZN = 1) 1.25 g cm 3 ( HORIZN = 2) 1.40 g cm 3 ( HORIZN = 3) 1.40 g cm 3 ( HORIZN = 4) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Initial Water Content ( THETO) 0.32 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3) Field Capacity values, PRZM Scenario Guidance ( 2004) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 5 cm ( HORIZN = 2) 2 cm ( HORIZN = 3) PRZM Scenario Guidance ( 2004)

Field Capacity ( THEFC) 0.32 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3, 4) GLEAMS Table H 3( 1990)

Wilting Point ( THEWP) 0.12 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3, 4) GLEAMS Table H 3( 1990)

Organic Carbon Content ( OC) 0.45% ( HORIZN = 1) 0.45% ( HORIZN = 2) 0.15% ( HORIZN = 3) 0.15% ( HORIZN = 4) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/); Adjusted using the relationship % OC = 0.6x% Organic Matter ( Doucette 2000)

2. Washington Beans ( WAbeansCRA)

The field used to represent bean production in Central Washington is located in Grant County in the Columbia Basin. The meteorological file, Yakima, WA represents the MLRA regions 7 and 8. Beans are planted in early summer and harvested in September. For this scenario, Ekrub fine sand was selected as a representative soil type because it supports bean crops. Ekrub fine sand is a hydrologic group C soil that is classified as sandy skeletal, mixed, mesic, shallow xeric Haplodurids. The Ekrub series of soils is shallow, somewhat excessively drained, formed in eolian sands overlying a lime silica indurated duripan. These soils occur on terraces with slopes of 0 to 25 percent. This soil type occurs in South central Washington where itis mostly used for range ( USDA 1996).

PRZM 3.12 Scenario Input Parameters for Grant County, Washington  Beans Section II. D. 6  Page 90 of 120 Parameter Value Source Starting Date January 1, 1961 Meteorological File  Yakima, Grant County, Washington Ending Date December 31, 1990 Meteorological File  Yakima, Grant County, Washington Pan Evaporation Factor ( PFAC) 0.71 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.20 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD) 17 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.28 tons EI 1* Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) USLE LS Factor ( USLELS) 3.6 Based on slope taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) , PRZM manual length 400 m, 12% slope USLE P Factor ( USLEP) 0.6 PRZM Manual Table 5.6 ( EPA, 1998)

Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA 2004) NRCS Hyetograph ( IREG) 3 PRZM Manual Figure 5.12 ( EPA, 1998)

Slope ( SLP) 12.5% Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Hydraulic Length ( HL) 464 ( reservoir) Shipman Reservoir ( EPA 2004) Irrigation Flag ( IRFLAG) 0 From PRZM Scenario Guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Leaching Factor ( FLEACH) Not applicable Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops (. EPA 2004) Initial Surface Condition ( ISCOND) 1 Consulted extension agent, crops are rotated Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Section II. D. 6  Page 91 of 120 Maximum rainfall interception storage of crop ( CINTCP) 0.1 cm Taken from OR snap beans scenario.

Maximum Active Root Depth ( AMXDR) 18 cm Taken from OR snap beans scenario.

Maximum Canopy Coverage ( COVMAX) 80% Taken from OR snap beans scenario.

Soil Surface Condition After Harvest ( ICNAH) 1 Taken from OR snap beans scenario.

Date of Crop Emergence ( EMD, EMM, IYREM) 61/ 6/ 61 Taken from OR snap beans scenario.

Date of Crop Maturity ( MAD, MAM, IYRMAT) 18/ 8/ 61 Taken from OR snap beans scenario.

Date of Crop Harvest ( HAD, HAM, IYRHAR) 2/ 9/ 61 Taken from OR snap beans scenario.

Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 84, 86, 87 Gleams Manual Table A. 3, ( Hydrological soil C), SR Conservation Tillage/ poor, Cropping and Residue = Row Crop Contour/ good ( USDA, 1990) Manning's N Value ( MNGN) .011 RUSLE Project ( A04ONONC. dat) Onion fields in Centralia, WA USLE C Factor ( USLEC) .806 .812 .818 .822 .827 .831 .836 .786 .885 .887 .869 .829 .778 .733 .691 .666 .690 .707 .554 .582 .617 .658 .702 .735 .759 .777 .790 .799 RUSLE Project ( A04ONONC. dat) Onion fields in Centralia, WA Soil Parameters Total Soil Depth ( CORED) 45 cm NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Number of Horizons ( NHORIZ) 3 NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Horizon Thickness ( THKNS) 8 cm ( HORIZN = 1) 22 cm ( HORIZN = 2) 15 cm ( HORIZN = 3) Bulk Density ( BD) 1.45 g cm 3 ( HORIZN = 1) 1.55 g cm 3 ( HORIZN = 2) 1.55 g cm 3 ( HORIZN = 3) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Initial Water Content ( THETO) 0.18 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3) Field Capacity values, PRZM Scenario Guidance ( 2004) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 2 cm ( HORIZN = 2) 5 cm ( HORIZN = 3) PRZM Scenario Guidance ( 2004)

Field Capacity ( THEFC) 0.18 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3) GLEAMS Table H 3( 1990) Section II. D. 6  Page 92 of 120 Wilting Point ( THEWP) 0.03 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3) GLEAMS Table H 3( 1990)

Organic Carbon Content ( OC) 0.15% ( HORIZN = 1, 2, 3) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/); Adjusted using the relationship % OC = 0.6x% Organic Matter ( Doucette 2000)

3. Washington Onions ( WAonionsCRA)

The field used to represent onion production in Central Washington is representative of a field in Grant county. The meteorological file, Yakima, WA represents the MLRA region 7, 8. Washington produces 16.2 percent of the U. S. dry summer onions, ranking third in the U. S. Washington storage onion production is primairly in the central part of the state in Grant, Franklin, Benton and Adams counties. Onions are cool season crops which can grow in a variety of soil types. Onions in Grant county are grown in 3 to 4 year rotations with carrots, sweet corn, cereals and potatoes. Onions are planted on beds in multiple rows ( 2 12). Seeds are planted 1/ 4 to ½ inch deep. Most onions are irrigated ( NSF 2003). For this scenario, Ekrub fine sand was selected as a representative soil type because it supports onion crops. Ekrub fine sand is a hydrologic group C soil that is classified as sandy skeletal, mixed, mesic, shallow xeric Haplodurids. The Ekrub series of soils is shallow, somewhat excessively drained, formed in eolian sands overlying a lime silica indurated duripan. These soils occur on terraces with slopes of 0 to 25 percent. This soil type occurs in South central Washington where it is mostly used for range ( USDA 1996).

PRZM 3.12 Scenario Input Parameters for Grant County, Washington  Onions Parameter Value Source Starting Date January 1, 1961 Meteorological File  Yakima, Grant County, Washington Ending Date December 31, 1990 Meteorological File  Yakima, Grant County, Washington Pan Evaporation Factor ( PFAC) 0.71 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.20 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD 17 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.28 tons EI 1* Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) USLE LS Factor ( USLELS) 3.6 Based on slope taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) , PRZM manual length 400 m, 12% slope USLE P Factor ( USLEP) 0.5 PRZM Manual Table 5.6 ( EPA, 1998) Section II. D. 6  Page 93 of 120 Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA 2004) NRCS Hyetograph ( IREG) 3 PRZM Manual Figure 5.12 ( EPA, 1998)

Slope ( SLP) 12.5% Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Hydraulic Length ( HL) 464 ( reservoir) Shipman Reservoir ( EPA 2004) Irrigation Flag ( IRFLAG) 0 From PRZM Scenario Guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Leaching Factor ( FLEACH) Not applicable Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops (. EPA 2004) Initial Surface Condition ( ISCOND) 1 Consulted extension agent, crops are rotated Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data.

Maximum rainfall interception storage of crop ( CINTCP) 0.5 cm Taken from CA onion scenario.

Maximum Active Root Depth ( AMXDR) 35 cm Taken from CA onion scenario.

Maximum Canopy Coverage ( COVMAX) 80% Taken from CA onion scenario.

Soil Surface Condition After Harvest ( ICNAH) 1 Taken from CA onion scenario.

Date of Crop Emergence ( EMD, EMM, IYREM) 1/ 6/ 61 Oregon State University Extension and Experiment Station http:// eesc. orst. edu/ agcomwebfile/ edmat/ html/ p nw546/ pnw546. html# anchor256349 Date of Crop Maturity ( MAD, MAM, IYRMAT) 30/ 8/ 61 Oregon State University Extension and Experiment Station http:// eesc. orst. edu/ agcomwebfile/ edmat/ html/ p nw546/ pnw546. html# anchor256349 Date of Crop Harvest ( HAD, HAM, IYRHAR) 10/ 9/ 61 Oregon State University Extension and Experiment Station http:// eesc. orst. edu/ agcomwebfile/ edmat/ html/ p nw546/ pnw546. html# anchor256349 Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation Section II. D. 6  Page 94 of 120 SCS Curve Number ( CN) 84, 86, 87 Gleams Manual Table A. 3, ( Hydrological soil C), SR Conservation Tillage/ poor, Cropping and Residue = Row Crop Contour/ good ( USDA, 1990) Manning's N Value ( MNGN) .011 RUSLE Project ( A04ONONC. dat) Onion fields in Centralia, WA USLE C Factor ( USLEC) .806 .812 .818 .822 .827 .831 .836 .786 .885 .887 .869 .829 .778 .733 .691 .666 .690 .707 .554 .582 .617 .658 .702 .735 .759 .777 .790 .799 RUSLE Project ( A04ONONC. dat) Onion fields in Centralia, WA Soil Parameters Total Soil Depth ( CORED) 45 cm NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Number of Horizons ( NHORIZ) 3 NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Horizon Thickness ( THKNS) 8 cm ( HORIZN = 1) 22 cm ( HORIZN = 2) 15 cm ( HORIZN = 3) Bulk Density ( BD) 1.45 g cm 3 ( HORIZN = 1) 1.55 g cm 3 ( HORIZN = 2) 1.55 g cm 3 ( HORIZN = 3) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Initial Water Content ( THETO) 0.18 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3) Field Capacity values, PRZM Scenario Guidance ( 2004) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 2 cm ( HORIZN = 2) 5 cm ( HORIZN = 3) PRZM Scenario Guidance ( 2004)

Field Capacity ( THEFC) 0.18 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3) GLEAMS Table H 3 ( 1990)

Wilting Point ( THEWP) 0.03 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3) GLEAMS Table H 3 ( 1990)

Organic Carbon Content ( OC) 0.15% ( HORIZN = 1, 2, 3) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/); Adjusted using the relationship % OC = 0.6x% Organic Matter ( Doucette 2000)

4. Washington Potatoes ( WApotatoCRA)

The field used to represent potato production in Central Washington is located in Grant County in the Columbia Basin. The meteorological file, Yakima, WA represents the MLRA regions 7 and 8. Potatoes are planted in the spring and harvested in the summer and fall. Common potato varieties grown in Washington include russets, which are grown for french fries and fresh market. Other varieties include yellow, red and blue potatoes ( WSPC 2004). For this scenario, Scoon silt loam was selected as a representative soil type because it supports potato crops in Grant county in Washington. Scoon silt loam is a hydrologic group D soil that is classified as loamy, mixed, superactive, mesic and shallow Xeric Haplodurids. The Scoon series of soils is shallow to a duripan, well drained, and formed in loess and silty alluvium over a duripan. These Section II. D. 6  Page 95 of 120 soils occur on terraces and alluvial fans with slopes of 0 to 30 percent. This soil type occurs on the in South central Washington and Southern Idaho and is mostly used for irrigated crop production and range ( USDA 2001).

PRZM 3.12 Scenario Input Parameters for Grant County, Washington  Potato Parameter Value Source Starting Date January 1, 1961 Meteorological File  Yakima, Grant County, Washington Ending Date December 31, 1990 Meteorological File  Yakima, Grant County, Washington Pan Evaporation Factor ( PFAC) 0.71 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.20 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD) 17 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Parameter Value Source Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.55 tons EI 1* Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) USLE LS Factor ( USLELS) 0.30 Based on slope taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) , PRZM manual length 400 m, 2% slope USLE P Factor ( USLEP) 0.3 PRZM Manual Table 5.6 ( EPA, 1998)

Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA 2004) NRCS Hyetograph ( IREG) 3 PRZM Manual Figure 5.12 ( EPA, 1998)

Slope ( SLP) 2.5% From http:// soils. usda. gov/ official soil series description ( slope range = 0 1%) Hydraulic Length ( HL) 356 ( pond) 464 ( reservoir) Shipman Reservoir ( EPA 2004)

Irrigation Flag ( IRFLAG) 0 From PRZM Scenario Guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Leaching Factor ( FLEACH) Not applicable Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Section II. D. 6  Page 96 of 120 Initial Surface Condition ( ISCOND) 1 Consulted extension agent, crops are rotated Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data.

Maximum rainfall interception storage of crop ( CINTCP) 0.1 cm PRZM Manual ( Carsel et al., 1998)

Maximum Active Root Depth ( AMXDR) 30 cm Consulted extension agent Maximum Canopy Coverage ( COVMAX) 40% Consulted extension agent Soil Surface Condition After Harvest ( ICNAH) 3 PRZM Manual ( Carsel et al., 1998)

Date of Crop Emergence ( EMD, EMM, IYREM) 1/ 5/ 61 Consulted extension agent Date of Crop Maturity ( MAD, MAM, IYRMAT) 15/ 9/ 61 Consulted extension agent Date of Crop Harvest ( HAD, HAM, IYRHAR) 1/ 10/ 61 Consulted extension agent Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 91, 89, 90 Gleams Manual Table A. 3, ( Hydrological soil D) ( USDA, 1990) Manning's N Value ( MNGN) .014 RUSLE Project ( A04PIPC. dat)

USLE C Factor ( USLEC) .741 .753 .764 .774 .784 .795 .805 .750 .757 .858 .880 .811 .582 .389 .290 .125 .055 .050 .188 .486 .520 .582 .630 .666 .694 .713 .729 RUSLE Project ( A04PIPC. dat)

Soil Parameters Total Soil Depth ( CORED) 40 cm http:// soils. usda. gov/ Note: Only upper 16 inches of soil had data on physical properties. Number of Horizons ( NHORIZ) 3 NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 5 cm ( HORIZN = 2) 25 cm ( HORIZN = 3) Bulk Density ( BD) 1.25 g cm 3 ( HORIZN = 1) 1.25 g cm 3 ( HORIZN = 2) 1.4 g cm 3 ( HORIZN = 3) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Initial Water Content ( THETO) 0.32 cm3 H20 cm3 soil Field Capacity values, PRZM Scenario Guidance ( 2004) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 5 cm ( HORIZN = 2) 5 cm ( HORIZN = 3) PRZM Scenario Guidance ( 2004) Section II. D. 6  Page 97 of 120 Field Capacity ( THEFC) 0.32 cm3 H20 cm3 soil GLEAMS Table H 3( 1990), NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Wilting Point ( THEWP) 0.12 cm3 H20 cm3 soil GLEAMS Table H 3( 1990), NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Organic Carbon Content ( OC) 0.45% ( HORIZN = 1, 2) 0.15% ( HORIZN = 3) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/); Adjusted using the relationship % OC = 0.6x% Organic Matter ( Doucette 2000)

5. Washington Sweet Corn ( WAswcornCRA)

This scenario was developed specifically to fill in usage for the N methyl Carbamate Cumulative assessment for total NMC use in Grant County, WA. The scenario uses the climate and soil inputs from the WA onion scenario with crop parameters specific to sweet corn. The meteorological file, Yakima, WA, represents the MLRA region 7, 8. For this scenario, Ekrub fine sand was selected as a representative soil type because it supports onion crops. Ekrub fine sand is a hydrologic group C soil that is classified as sandy skeletal, mixed, mesic, shallow xeric Haplodurids. The Ekrub series of soils is shallow, somewhat excessively drained, formed in eolian sands overlying a lime silica indurated duripan. These soils occur on terraces with slopes of 0 to 25 percent. This soil type occurs in South central Washington where it is mostly used for range ( USDA 1996).

PRZM 3.12 Scenario Input Parameters for Grant County, Washington   Sweet Corn Parameter Value Source Starting Date January 1, 1961 Meteorological File  Yakima, Grant County, Washington Ending Date December 31, 1990 Meteorological File  Yakima, Grant County, Washington Pan Evaporation Factor ( PFAC) 0.71 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.20 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD 17 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.28 tons EI 1* Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) USLE LS Factor ( USLELS) 3.6 Based on slope taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) , PRZM manual length 400 m, 12% slope USLE P Factor ( USLEP) 0.5 PRZM Manual Table 5.6 ( EPA, 1998)

Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA 2004) NRCS Hyetograph ( IREG) 3 PRZM Manual Figure 5.12 ( EPA, 1998) Section II. D. 6  Page 98 of 120 Slope ( SLP) 12.5% Taken from NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Hydraulic Length ( HL) 464 ( reservoir) Shipman Reservoir ( EPA 2004) Irrigation Flag ( IRFLAG) 0 From PRZM Scenario Guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Leaching Factor ( FLEACH) Not applicable Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops (. EPA 2004) Initial Surface Condition ( ISCOND) 1 Consulted extension agent, crops are rotated Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data.

Maximum rainfall interception storage of crop ( CINTCP) 0.25 cm Taken from OR sweet corn scenario.

Maximum Active Root Depth ( AMXDR) 90 cm Taken from OR sweet corn scenario.

Maximum Canopy Coverage ( COVMAX) 100% Taken from OR sweet corn scenario.

Soil Surface Condition After Harvest ( ICNAH) 1 Taken from OR sweet corn scenario.

Date of Crop Emergence ( EMD, EMM, IYREM) 10/ 5/ 61 Oregon State University Extension and Experiment Station http:// eesc. orst. edu/ agcomwebfile/ edmat/ html/ p nw546/ pnw546. html# anchor256349 Date of Crop Maturity ( MAD, MAM, IYRMAT) 21/ 8/ 61 Oregon State University Extension and Experiment Station http:// eesc. orst. edu/ agcomwebfile/ edmat/ html/ p nw546/ pnw546. html# anchor256349 Date of Crop Harvest ( HAD, HAM, IYRHAR) 10/ 9/ 61 Oregon State University Extension and Experiment Station http:// eesc. orst. edu/ agcomwebfile/ edmat/ html/ p nw546/ pnw546. html# anchor256349 Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 84, 86, 87 Gleams Manual Table A. 3, ( Hydrological soil C), SR Conservation Tillage/ poor, Cropping and Residue = Row Crop Contour/ good ( USDA, 1990) Section II. D. 6  Page 99 of 120 Manning's N Value ( MNGN) .011 RUSLE Project ( A04ONONC. dat) Onion fields in Centralia, WA USLE C Factor ( USLEC) .806 .812 .818 .822 .827 .831 .836 .786 .885 .887 .869 .829 .778 .733 .691 .666 .690 .707 .554 .582 .617 .658 .702 .735 .759 .777 .790 .799 RUSLE Project ( A04ONONC. dat) Onion fields in Centralia, WA Soil Parameters Total Soil Depth ( CORED) 45 cm NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Number of Horizons ( NHORIZ) 3 NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/) Horizon Thickness ( THKNS) 8 cm ( HORIZN = 1) 22 cm ( HORIZN = 2) 15 cm ( HORIZN = 3) Bulk Density ( BD) 1.45 g cm 3 ( HORIZN = 1) 1.55 g cm 3 ( HORIZN = 2) 1.55 g cm 3 ( HORIZN = 3) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/)

Initial Water Content ( THETO) 0.18 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3) Field Capacity values, PRZM Scenario Guidance ( 2004) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 2 cm ( HORIZN = 2) 5 cm ( HORIZN = 3) PRZM Scenario Guidance ( 2004)

Field Capacity ( THEFC) 0.18 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3) GLEAMS Table H 3 ( 1990)

Wilting Point ( THEWP) 0.03 cm3 H20 cm3 soil ( HORIZN = 1, 2, 3) GLEAMS Table H 3 ( 1990)

Organic Carbon Content ( OC) 0.15% ( HORIZN = 1, 2, 3) NRCS Soil Data Mart ( http:// soildatamart. nrcs. usda. gov/); Adjusted using the relationship % OC = 0.6x% Organic Matter ( Doucette 2000) Section II. D. 6  Page 100 of 120 K. Southeast Region Scenario Documentation 1. California Alfalfa ( CAalfalfa0C)

The field used to represent alfalfa production in California is located in San Joaquin County in the Central Valley, although the crop is grown throughout the Central Valley and as far south as the Imperial Valley. According to the 1997 Census of Agriculture, California is ranked 1st in pounds of alfalfa hay harvested and among the top 10 in acres planted. Alfalfa is a perennial crop, planted early in the year and maintained under continuous cultivation on a 4 to 5 year cycle at which time a new crop is planted.. Planting depths range from 0.25 to 1.0 inches, depending on soil texture, on level seed beds. Row spacing is approximately 30 inches; nearly all alfalfa is irrigated in California by flooding. Cuttings range from 3 to 5 per year under most conditions. Alfalfa prefers well drained soil with a pH near neutral. Root systems rarely exceed 2 feet in California and cuttings occur when the plant reaches a height of approximately 30 inches. The soil selected to simulate the field is a benchmark soil, Sacramento clay. Sacramento clay, is a very fine, smectitic, thermic Cumulic Vertic Endoaquolls. These soils are often used for alfalfa cultivation providing the water table is low. Sacramento clay is a poorly to very poorly drained, slowly permeable soil with very slow to slow runoff. These soils formed in fine textured alluvium of mixed origin and are of moderate extent. They are generally found in level basins at elevations near sea level to 60 feet. The soil is typical of soils used for a variety of row crops, rice, safflower and alfalfa. Sacramento clay is a Hydrologic Group D soil.

PRZM 3.12 Scenario Input Parameters for San Joaquin County, California  Alfalfa Parameter Value Source Starting Date January 1, 1961 Meteorological File  Sacramento, CA ( W23232) Ending Date December 31, 1990 Meteorological File  Sacramento, CA ( W23232) Pan Evaporation Factor ( PFAC) 0.73 PRZM Manual Figure 5.1 ( EPA, 1998)

Snowmelt Factor ( SFAC) 0.45 cm C 1 PRZM Manual Table 5.1 ( EPA, 1998)

Minimum Depth of Evaporation ( ANETD) 15.0 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.20 tons EI 1* NRI  Average value listed for the soil series Sacramento USLE LS Factor ( USLELS) 0.19 NRI  Average value listed for the soil series Sacramento USLE P Factor ( USLEP) 1.00 NRI  Average value listed for the soil series Sacramento Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA, 1999) Section II. D. 6  Page 101 of 120 NRCS Hyetograph ( IREG) 1 PRZM Manual Figure 5.12 ( EPA, 1998)

Slope ( SLP) 2% Marcia Campbell Matthews; San Joaquin County Cooperative Extension Agent. 209 468 2085 Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Irrigation Flag ( IRFLAG) 0 Based on current EPA guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Based on current EPA guidance ( 2004) Leaching Factor ( FLEACH) Not applicable Based on current EPA guidance ( 2004)

Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Based on current EPA guidance ( 2004)

Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Based on current EPA guidance ( 2004)

Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA. 2001) Initial Surface Condition ( ISCOND) 1 Marcia Campbell Matthews; San Joaquin County Cooperative Extension Agent. 209 468 2085 Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological File  Sacramento, CA ( W23232) Maximum rainfall interception storage of crop ( CINTCP) 0.25 Maximum recommended value for grass ( EPA, 2001)

Maximum Active Root Depth ( AMXDR) 60 cm Marcia Campbell Matthews; San Joaquin County Cooperative Extension Agent. 209 468 2085 Maximum Canopy Coverage ( COVMAX) 100 Marcia Campbell Matthews; San Joaquin County Cooperative Extension Agent. 209 468 2085 Soil Surface Condition After Harvest ( ICNAH) 1 Marcia Campbell Matthews; San Joaquin County Cooperative Extension Agent. 209 468 2085 Date of Crop Emergence ( EMD, EMM, IYREM) 10/ 01 Value set to approximate planting cycle. Alfalfa is planted one every five years with multiple cuttings in every year Date of Crop Maturity ( MAD, MAM, IYRMAT) 28/ 12 Value set to approximate planting cycle. Alfalfa is planted one every five years with multiple cuttings in every year Date of Crop Harvest ( HAD, HAM, IYRHAR) 31/ 12 Value set to approximate planting cycle. Alfalfa is planted one every five years with multiple cuttings in every year Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 90, 88, 89 Gleams Manual Table A. 3, Pasture/ Range, Non CNT, Poor ( USDA, 1990) Manning's N Value ( MNGN) 0.023 RUSLE Project, A01OCOCM; Orchard, cover alley, Mulch till, Olympia, WA ( USDA, 2000) USLE C Factor ( USLEC) 0.046  0.221 RUSLE Project; A01OCOCM; Orchard, cover alley, Mulch till, Olympia, WA. Variable with date ( USDA, 2000) Section II. D. 6  Page 102 of 120 Sacramento Soil Parameters Total Soil Depth ( CORED) 176 cm Number of Horizons ( NHORIZ) 4 ( Top horizon split in two) NRCS, National Soils Characterization Database ( NRCS, 2001)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 8 cm ( HORIZN = 2) 157 cm ( HORIZN = 3) 1 cm ( HORIZN = 4) Bulk Density ( BD) 1.43 g cm 3 ( HORIZN = 1, 2) 1.29 g cm 3 ( HORIZN = 3) 1.48 g cm 3 ( HORIZN = 4) Initial Water Content ( THETO) 0.42 cm3 H2O cm3 soil ( HORIZN = 1, 2) 0.44 cm3 H2O cm3 soil ( HORIZN = 3) 0.39 cm3 H2O cm3 soil ( HORIZN = 4) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 4.0 cm ( HORIZN = 2) 1 cm ( HORIZN = 3,4) Field Capacity ( THEFC) 0.44 cm3 H2O cm3 soil ( HORIZN = 1, 2) 0.42 cm3 H2O cm3 soil ( HORIZN = 3) 0.39 cm3 H2O cm3 soil ( HORIZN = 4) Wilting Point ( THEWP) 0.36 cm3 H2O cm3 soil ( HORIZN = 1,2,3) 0.3 cm3 H2O cm3 soil ( HORIZN = 4) Organic Carbon Content ( OC) 1.77% ( HORIZN = 1,2) 0.84% ( HORIZN = 3,4) NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/)

2. California Citrus ( CAcitrus0C)

The field used to represent citrus production in California is located in Fresno County in the Central Valley, although citrus production areas are quite extensive ( San Joaquin, Coastal Intermediate Region, Imperial Valley, Coachella Valley, and the Southern Interior Region). According to the 1997 Census of Agriculture, California is the major producer of citrus ( lemons and oranges) for the fresh market, and among the highest producers in other citrus ( grapefruit, tangerines, tangelos, and mandarins). Citrus is generally grown on the foothills to avoid frost damage. Areas under and between rows of trees are generally non cultivated/ non maintained. Row spacing is approximately 22 feet and between tree spacing is approximately 18 feet. Row canopies tend to be 100 percent, while the canopy between rows is less to permit the operation of maintenance and harvest equipment. Irrigation is mostly by low volume drip or micro sprinkler systems, although furrow and overhead sprinklers are also used. The soil selected to Section II. D. 6  Page 103 of 120 simulate the field is a benchmark soil, Exeter loam. Exeter loam, is a fine loamy, mixed, superactive, thermic Typic Durixeralfs. These soils are often used for citrus production under irrigation. Exeter loam is a moderately deep, moderately well drained, very slow to medium runoff soil that formed in alluvium mainly from granite sources. The soil also consists of a duripan. The Exeter loam has moderately slow permeability above the duripan and very slow permeability within the duripan. These soil are generally found on alluvial fans and stream terraces at elevations of up to 700 feet above mean sea level and have slopes of 0 to 9 percent. The soil is extensive in MLRA 17. Exeter loam is a Hydrologic Group C soil.

PRZM 3.12 Scenario Input Parameters for Fresno County, California  Citrus Parameter Value Source Starting Date January 1, 1961 Meteorological File  Sacramento, CA ( W23232) Ending Date December 31, 1990 Meteorological File  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)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.28 tons EI 1* NRI  Average value listed for the soil series Exeter USLE LS Factor ( USLELS) 0.21 NRI  Average value listed for the soil series Exeter USLE P Factor ( USLEP) 1.0 NRI  Average value listed for the soil series Exeter 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) 5% Mark Freeman, Fresno County Cooperative Extension Agent. Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Irrigation Flag ( IRFLAG) 0 Based on current EPA guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Based on current EPA guidance ( 2004) Leaching Factor ( FLEACH) Not applicable Based on current EPA guidance ( 2004)

Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Based on current EPA guidance ( 2004)

Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Based on current EPA guidance ( 2004)

Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Section II. D. 6  Page 104 of 120 Initial Surface Condition ( ISCOND) 3 Mark Freeman, Fresno County Cooperative Extension Agent. Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological File Maximum rainfall interception storage of crop ( CINTCP) 0.25 Maximum recommended value for grass ( EPA, 2001)

Maximum Active Root Depth ( AMXDR) 60 cm Mark Freeman, Fresno County Cooperative Extension Agent. Maximum Canopy Coverage ( COVMAX) 80 Mark Freeman, Fresno County Cooperative Extension Agent. Soil Surface Condition After Harvest ( ICNAH) 3 Mark Freeman, Fresno County Cooperative Extension Agent. Date of Crop Emergence ( EMD, EMM, IYREM) 02/ 01 Value set to a default evergreen cycle with no specific crop growth milestone such as flowering of fruit set. Date of Crop Maturity ( MAD, MAM, IYRMAT) 03/ 01 Value set to a default evergreen cycle with no specific crop growth milestone such as flowering of fruit set. Date of Crop Harvest ( HAD, HAM, IYRHAR) 31/ 12 Value set to a default evergreen cycle with no specific crop growth milestone such as flowering of fruit set. 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, Meadows, no fallow conditions ( USDA, 1990) Manning's N Value ( MNGN) 0.023 RUSLE Project; D26CCCCM for cover alley citrus ( USDA, 2000) USLE C Factor ( USLEC) 0.096  0.150 RUSLE Project; Variable with date, D26CCCCM for cover alley citrus ( USDA, 2000) Exeter Soil Parameters Total Soil Depth ( CORED) 183 cm Number of Horizons ( NHORIZ) 2 ( Base horizons) NRCS, National Soils Characterization Database ( NRCS, 2001)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 173 cm ( HORIZN = 2) Bulk Density ( BD) 1.59 g cm 3 ( HORIZN = 1) 1.76 g cm 3 ( HORIZN = 2) Initial Water Content ( THETO) 0.16 cm3 H2O cm3 soil ( HORIZN = 1) 0.2 cm3 H2O cm3 soil ( HORIZN = 2) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 1 cm ( HORIZN = 2) Field Capacity ( THEFC) 0.16 cm3 H2O cm3 soil ( HORIZN = 1) 0.2 cm3 H2O cm3 soil ( HORIZN = 2) NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/) Section II. D. 6  Page 105 of 120 Wilting Point ( THEWP) 0.06 cm3 H2O cm3 soil ( HORIZN = 1) 0.11 cm3 H2O cm3 soil ( HORIZN = 2) Organic Carbon Content ( OC) 0.46% ( HORIZN = 1) 0.19% ( HORIZN = 2)

3. California Cotton ( CAcotton0C)

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.

PRZM 3.12 Scenario Input Parameters for Fresno County, California  Cotton Parameter Value Source Starting Date January 1, 1961 Meteorological File  Sacramento, CA ( W23232) Ending Date December 31, 1990 Meteorological File  Sacramento, CA ( W23232) 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)

Erosion and Landscape Parameters 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) Section II. D. 6  Page 106 of 120 Slope ( SLP) 2.5% Mid point of soil series range ( EPA, 2001) Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Irrigation Flag ( IRFLAG) 0 Based on current EPA guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Based on current EPA guidance ( 2004) Leaching Factor ( FLEACH) Not applicable Based on current EPA guidance ( 2004)

Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Based on current EPA guidance ( 2004)

Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Based on current EPA guidance ( 2004)

Crop Parameters 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) 30 Set to weather data. Meteorological File

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) Twisselman Soil Parameters Total Soil Depth ( CORED) 100 cm NRCS, National Soils Characterization Database ( NRCS, 2001) Section II. D. 6  Page 107 of 120 Number of Horizons ( NHORIZ) 3 ( Top horizon split in two)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 26 cm ( HORIZN = 2) 64 cm ( HORIZN = 3) Bulk Density ( BD) 1.45 g cm 3 ( HORIZN = 1) 1.5 g cm 3 ( HORIZN = 2) 1.6 g cm 3 ( HORIZN = 3) Initial Water Content ( THETO) 0.36 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.317 cm3 H2O cm3 soil ( HORIZN = 3) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 2 cm ( HORIZN = 2,3) Field Capacity ( THEFC) 0.36 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.317 cm3 H2O cm3 soil ( HORIZN = 3) Wilting Point ( THEWP) 0.22 cm3 H2O cm3 soil ( HORIZN = 1,2) 0.197 cm3 H2O cm3 soil ( HORIZN = 3) Organic Carbon Content ( OC) 0.29% ( HORIZN = 1,2) 0.174% ( HORIZN = 3) NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/)

Ed Russell ( USDA_ NRCS, Fresno)

4. California Fruit Trees ( CAfruit0C)

The field used to represent non citrus fruit production in California is located in Fresno County in the Central Valley, although non citrus fruit production covers most of the central portion of the state, but mainly on Eastern slopes. According to the 1997 Census of Agriculture, California is the major producer of peaches, plums/ prunes, and kiwi for the fresh market, and among the highest producers in other non citrus fruit such as pears and apples. Areas under and between rows of trees may or may not be maintained depending on the location. Row spacing varies depending on the fruit tree ( from approximately 15 to 25 feet) as does the tree spacing ( approximately 12 to 20 or more feet). Row canopies tend to be very close to 100 percent, while the canopy between rows is much less to permit the operation of maintenance and harvest equipment. Irrigation is by furrow and flood for most crops, but low volume drip or micro sprinkler systems are growing in popularity. The soil selected to simulate the field is a benchmark soil, Exeter loam. Exeter loam, is a fine loamy, mixed, superactive, thermic Typic Durixeralfs. These soils are often used for citrus production under irrigation. Exeter loam is a moderately deep, moderately well drained, very slow to medium runoff soil that formed in alluvium mainly from granite sources. The soil also consists of a duripan. The Exeter loam has moderately slow permeability above the duripan and very slow permeability within the duripan. These soil are generally found on alluvial fans and stream terraces at elevations of up to 700 feet above mean sea level and have slopes of 0 to 9 percent. The soil is extensive in MLRA 17. Exeter loam is a Hydrologic Group C soil. Section II. D. 6  Page 108 of 120 PRZM 3.12 Scenario Input Parameters for Fresno County, California  Fruit ( non Citrus) Parameter Value Source Starting Date January 1, 1961 Meteorological File  Sacramento, CA ( W23232) Ending Date December 31, 1990 Meteorological File  Sacramento, CA ( W23232) Pan Evaporation Factor ( PFAC) 0.73 Kurt Hembree ( 559.456.7556), UC Cooperative Extension Office, Fresno County Snowmelt Factor ( SFAC) 0.0 cm C 1 Kurt Hembree ( 559.456.7556), UC Cooperative Extension Office, Fresno County Minimum Depth of Evaporation ( ANETD) 17.0 cm PRZM Manual Figure 5.2 ( EPA, 1998)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.34 tons EI 1* NRI  Average value listed for the soil series Exeter USLE LS Factor ( USLELS) 0.018 NRI  Average value listed for the soil series Exeter USLE P Factor ( USLEP) 1.0 NRI  Average value listed for the soil series Exeter Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA, 1999) NRCS Hyetograph ( IREG) 2 PRZM Manual Figure 5.12 ( EPA, 1998); based on crops grown on Eastern side of slopes. Slope ( SLP) 9% Kurt Hembree ( 559.456.7556), UC Cooperative Extension Office, Fresno County Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Irrigation Flag ( IRFLAG) 0 Based on current EPA guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Based on current EPA guidance ( 2004) Leaching Factor ( FLEACH) Not applicable Based on current EPA guidance ( 2004)

Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Based on current EPA guidance ( 2004)

Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Based on current EPA guidance ( 2004)

Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Initial Surface Condition ( ISCOND) 1 Mark Freeman, Fresno County Cooperative Extension Agent. Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological Maximum rainfall interception storage of crop ( CINTCP) 0.25 Maximum recommended value for grass ( EPA, 2001) Section II. D. 6  Page 109 of 120 Maximum Active Root Depth ( AMXDR) 30 cm Mark Freeman, Fresno County Cooperative Extension Agent. Maximum Canopy Coverage ( COVMAX) 90 Mark Freeman, Fresno County Cooperative Extension Agent. Soil Surface Condition After Harvest ( ICNAH) 3 Mark Freeman, Fresno County Cooperative Extension Agent. Date of Crop Emergence ( EMD, EMM, IYREM) 21/ 01 Value set to a dates for plums based on Health Effects Division information Date of Crop Maturity ( MAD, MAM, IYRMAT) 21/ 06 Value set to a dates for plums based on Health Effects Division information Date of Crop Harvest ( HAD, HAM, IYRHAR) 01/ 08 Value set to a dates for plums based on Health Effects Division information 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, Meadows, no fallow conditions ( USDA, 1990) Manning's N Value ( MNGN) 0.023 RUSLE Project; C21OCOCM for orchards, covered alley in Sacramento ( USDA, 2000) USLE C Factor ( USLEC) 0.034  0.221 RUSLE Project; Variable with date, C21OCOCM for orchards, covered alley in Sacramento ( USDA, 2000) Exeter Soil Parameters Total Soil Depth ( CORED) 183 cm Number of Horizons ( NHORIZ) 2 ( Base horizons) NRCS, National Soils Characterization Database ( NRCS, 2001)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 173 cm ( HORIZN = 2) Bulk Density ( BD) 1.59 g cm 3 ( HORIZN = 1) 1.76 g cm 3 ( HORIZN = 2) Initial Water Content ( THETO) 0.16 cm3 H2O cm3 soil ( HORIZN = 1) 0.2 cm3 H2O cm3 soil ( HORIZN = 2) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 1 cm ( HORIZN = 2) Field Capacity ( THEFC) 0.16 cm3 H2O cm3 soil ( HORIZN = 1) 0.2 cm3 H2O cm3 soil ( HORIZN = 2) Wilting Point ( THEWP) 0.06 cm3 H2O cm3 soil ( HORIZN = 1) 0.11 cm3 H2O cm3 soil ( HORIZN = 2) Organic Carbon Content ( OC) 0.46% ( HORIZN = 1) 0.19% ( HORIZN = 2) NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/) Section II. D. 6  Page 110 of 120 5. California Grapes ( CAgrapesC)

The field used to represent grape production in California is located in Southern San Joaquin Valley. According to the 1997 Census of Agriculture, California is the major producer of table, wine, and raisin grapes with 85 percent of California's production in the San Joaquin Valley and the bulk of the remainder in the Coachella Valley. Grapes need at least 3 ft of well drained soil, and are typically grown on sandy or sandy loam soils. Vine rows are usually kept weed free, but there is some growth in the winter. Surface soil around the vine row is usually sealed, but some plants can grow between vine rows. The soil between rows is usually disked. Row spacing varies depending on the terrain. Canopies between rows tend to be much less than 100 percent, while the canopy along the rows is 100 percent. Irrigation is mainly by drip irrigation, but some vineyards continue to use sprinkler systems. The soil selected to simulate the field is a benchmark soil, San Joaquin loam. San Joaquin loam, is a fine, mixed, active, thermic Abruptic Durixeralfs. These soils are often used for vineyards, fruit and nut production under irrigation. San Joaquin loam is a moderately deep, well and moderately well drained, medium to very high runoff soil that formed in alluvium mainly from granite sources. The soil also consists of a duripan. The San Joaquin loam has very slow permeability above the duripan and very slow permeability within the duripan. Some areas are subject to flooding. These soil are generally found on undulating terraces at elevations from 50 to 500 feet above mean sea level and have slopes of 0 to 9 percent. The soil is extensive in MLRA 17 along the Eastern slopes of the Sacramento and San Joaquin Valleys. San Joaquin loam is a Hydrologic Group C soil.

PRZM 3.12 Scenario Input Parameters for San Joaquin Valley, California  Grapes Parameter Value Source Starting Date January 1, 1961 Meteorological File  Sacramento, CA ( W23232) Ending Date December 31, 1990 Meteorological File  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)

Erosion and Landscape Parameters Method to Calculate Erosion ( ERFLAG) 4 ( MUSS) PRZM Manual ( EPA, 1998)

USLE K Factor ( USLEK) 0.28 tons EI 1* NRI  Average value listed for the soil series San Joaquin USLE LS Factor ( USLELS) 0.2 NRI  Average value listed for the soil series San Joaquin USLE P Factor ( USLEP) 1.0 NRI  Average value listed for the soil series San Joaquin Field Area ( AFIELD) 172 ha Area of Shipman Reservoir watershed ( EPA, 1999) NRCS Hyetograph ( IREG) 1 PRZM Manual Figure 5.12 ( EPA, 1998); based on crops grown on Eastern side of slopes. Section II. D. 6  Page 111 of 120 Slope ( SLP) 2% Paul Verdegaal, San Joaquin County Cooperative Extension 209_ 468_ 9494 Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Irrigation Flag ( IRFLAG) 0 Based on current EPA guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Based on current EPA guidance ( 2004) Leaching Factor ( FLEACH) Not applicable Based on current EPA guidance ( 2004)

Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Based on current EPA guidance ( 2004)

Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Based on current EPA guidance ( 2004)

Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Initial Surface Condition ( ISCOND) 3 Paul Verdegaal, San Joaquin County Cooperative Extension 209_ 468_ 9494 Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological File Maximum rainfall interception storage of crop ( CINTCP) 0.25 Maximum recommended value for grass ( EPA, 2001)

Maximum Active Root Depth ( AMXDR) 100 cm Paul Verdegaal, San Joaquin County Cooperative Extension 209_ 468_ 9494 Maximum Canopy Coverage ( COVMAX) 70 Paul Verdegaal, San Joaquin County Cooperative Extension 209_ 468_ 9494 Soil Surface Condition After Harvest ( ICNAH) 3 Paul Verdegaal, San Joaquin County Cooperative Extension 209_ 468_ 9494 Date of Crop Emergence ( EMD, EMM, IYREM) 01/ 02 Paul Verdegaal, San Joaquin County Cooperative Extension 209_ 468_ 9494 Date of Crop Maturity ( MAD, MAM, IYRMAT) 15/ 08 Paul Verdegaal, San Joaquin County Cooperative Extension 209_ 468_ 9494 Date of Crop Harvest ( HAD, HAM, IYRHAR) 31/ 08 Paul Verdegaal, San Joaquin County Cooperative Extension 209_ 468_ 9494 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, Meadows, no fallow conditions ( USDA, 1990) Manning's N Value ( MNGN) 0.023 RUSLE Project; C21GBGBC for grapes, Sacramento, bare ground ( USDA, 2000) USLE C Factor ( USLEC) 0.274  0.517 RUSLE Project; Variable with date, C21GBGBC for grapes, Sacramento, bare ground ( USDA, 2000) San Joaquin Soil Parameters Total Soil Depth ( CORED) 340 cm NRCS, National Soils Characterization Database ( NRCS, 2001) Section II. D. 6  Page 112 of 120 Number of Horizons ( NHORIZ) 2 ( Base horizons)

Horizon Thickness ( THKNS) 10 cm ( HORIZN = 1) 330 cm ( HORIZN = 2) Bulk Density ( BD) 1.84 g cm 3 ( HORIZN = 1) 1.6 g cm 3 ( HORIZN = 2) Initial Water Content ( THETO) 0.21 cm3 H2O cm3 soil ( HORIZN = 1) 0.28 cm3 H2O cm3 soil ( HORIZN = 2) Compartment Thickness ( DPN) 0.1 cm ( HORIZN = 1) 5 cm ( HORIZN = 2) Field Capacity ( THEFC) 0.21 cm3 H2O cm3 soil ( HORIZN = 1) 0.28 cm3 H2O cm3 soil ( HORIZN = 2) Wilting Point ( THEWP) 0.1 cm3 H2O cm3 soil ( HORIZN = 1) 0.15 cm3 H2O cm3 soil ( HORIZN = 2) Organic Carbon Content ( OC) 0.72% ( HORIZN = 1) 0.16% ( HORIZN = 2) NRCS, National Soils Characterization Database ( NRCS, 2001) http:// www. statlab. iastate. edu/ soils/ ssl/)

6. California Vegetables: Root & Bulb crops   Carrots ( CAcarrot0CRA), Garlic ( CAgarlic0CRA), Onion ( CAonion0C)

These scenarios were adapted for the N Methyl Carbamate cumulative assessment, using the weather, runoff, and soil parameters from the CA onion scenario, changing the scenarios to reflect crop specific parameters for carrots and garlic. All parameters are the same for these scenarios, except where noted in the table below.

The field used to represent onion production in California is located in Kern County in the San Joaquin Valley, although onion production areas are quite extensive ( San Joaquin, Coastal Intermediate Region, Imperial Valley, southern and central coastal regions, the high desert areas of Los Angeles County and the northern mountain valleys). According to the 1997 Census of Agriculture, California is the major producer of onions for the market. Bulb onions are planted from September through May and harvesting begins in April or May and completed by September. Onions are cools season, biennial plants that are commercially grown as an annual. Most onions are direct seeded, but transplants are used in some fall planted fields for an earlier harvest of short day and intermediate day varieties and to achieve uniform , jumbo sized bulbs. Seeds are planted uniformly at 2 to 3 inches between plants in a row. Onions are most commonly grown in multiple rows on raised beds 40 to 42 inches wide, but some production areas use 36 inch wide beds or beds of 60 to 80 inches. Distribution of rows across beds varies depending on irrigation method and planter. With drip and sprinkler irrigation ( most common types), rows are spaced equidistant across the bed at approximately 4 inch intervals. When furrow irrigation is used, the center of the bed is left vacant for salt accumulation with 2 or 3 rows planted on either side. Plant canopy can approach 100 percent in some Section II. D. 6  Page 113 of 120 narrow row fields grown under drip irrigation. Irrigation is required to avoid seed or plant dry out. Generally 24 to 36 inches of irrigated water per year is sufficient. Onions can grow on a wide range of soils.

Garlic is grown in the desert valleys, central coast, and San Joaquin Valley of California. It is typically planted in the fall ( mid September through November) and matures in late spring in the desert valleys and mid summer in the central coast and San Joaquin Valley ( UC Davis, 1976. Growing Garlic in California). Garlic is generally ready to harvest one month after maturity.

California is the top carrot producing state in the United States and the San Joaquin Valley / Kern County is the largest carrot producing region in the state, accounting for 75% of acreage ( USDA Crop Profile for Carrots in California). Carrots may be planted in December to March or in July to September. Harvest dates are from May to July for the winter planting and from November to February for the late summer planting.

The soil selected to represent the field is Ciervo clay. Ciervo clay, is a fine, semetic, thermic Vertic Haplocambids. These soils are often used for onion and other truck crop production under irrigation. Ciervo clay is a very deep, moderately well drained, medium to high runoff soil on fan skirts that formed in alluvium mainly from sedimentary rocks at elevation of 170 to 735 feet above mean sea level. The Ciervo clay has very slow permeability. Slopes range from 0 to 2 percent. The soil is of large extent in MLRA 17. Ciervo clay is a Hydrologic Group D soil.

PRZM 3.12 Scenario Input Parameters for Kern County, California   Bulb and Root Crops ( Onion, Garlic, Carrot) Parameter Value Source Starting Date January 1, 1961 Meteorological File  Sacramento, CA ( W23232) Ending Date December 31, 1990 Meteorological File  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)

Erosion and Landscape Parameters 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) 0.303 Haan and Barfield, 1979 USLE P Factor ( USLEP) 0.5 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) Section II. D. 6  Page 114 of 120 Slope ( SLP) 1% Mid point of the Soil Series, Ciervo Hydraulic Length ( HL) 464 m Shipman Reservoir ( EPA, 1999) Irrigation Flag ( IRFLAG) 0 Based on current EPA guidance ( 2004)

Irrigation Type ( IRTYP) Not applicable Based on current EPA guidance ( 2004) Leaching Factor ( FLEACH) Not applicable Based on current EPA guidance ( 2004)

Fraction of Water Capacity when Irrigation is Applied ( PCDEPL) Not applicable Based on current EPA guidance ( 2004)

Maximum Rate at which Irrigation is Applied ( RATEAP) Not applicable Based on current EPA guidance ( 2004)

Crop Parameters Initial Crop ( INICRP) 1 Set to one for all crops ( EPA, 2001) Initial Surface Condition ( ISCOND) 1 Default Number of Different Crops ( NDC) 1 Set to crops in simulation  generally one Number of Cropping Periods ( NCPDS) 30 Set to weather data. Meteorological File Maximum rainfall interception storage of crop ( CINTCP) 0.05 PRZM Input Collator ( Burns, 1992)

30 cm ( onion) Voss, R. E. Fresh Market Bulb Onion Production in California. U. fo CA Publication 7242. 1999. 45 cm ( garlic) Rooting depth averages 18 24 inches ( USDA crop profile for Garlic in CA) Maximum Active Root Depth ( AMXDR)

35 cm ( carrot) Confirmed by R. E. Voss UC Publ 7242 Maximum Canopy Coverage ( COVMAX) 80 Estimated based on aerial photography Soil Surface Condition After Harvest ( ICNAH) 1 Voss, R. E. 1999. Fresh Market Bulb Onion Production in California. U. fo CA Publication 7242. 11/ 01 ( 0nion) PIC Recommended dates adjusted according to RUSLE Project planting dates. 01/ 10 ( Garlic) Garlic typically planted mid Sept through Nov ( USDA Crop Profile, 2004) Date of Crop Emergence ( EMD, EMM, IYREM)

01/ 08 ( Carrot) Based on Jul Sep planting window; also planted Dec Mar ( USDA Crop Profile) 01/ 06 ( Onion) PIC Recommended dates adjusted according to RUSLE Project planting dates. 01/ 06 ( Onion) Garlic bulbs mature in late spring in desert valleys, midsummer in central coast, San Joaquin Valley ( UC Davis, Growing Garlic in CA, 1976) Date of Crop Maturity ( MAD, MAM, IYRMAT)

01/ 11 ( Carrot) Maturity set to coincide with harvest window ( 2 weeks between) Date of Crop Harvest ( HAD, HAM, IYRHAR) 15/ 06 ( Onion) PIC Recommended dates adjusted according to RUSLE Project planting dates. Section II. D. 6  Page 115 of 120 01/ 07 ( Garlic) Typical harvest dates July Sep ( WA crop profile); generally ready to harvest 1 mo after maturity ( CA crop profile) 15/ 11 ( Carrot) Nov Feb harvest window for winter planting; also May Jul harvest ( USDA Crop Profile) Maximum Dry Weight ( WFMAX) 0.0 Set to " 0" Not used in simulation SCS Curve Number ( CN) 92, 85, 86 Gleams Manual Table A. 3, Meadows, no fallow conditions ( USDA, 1990) Manning's N Value ( MNGN) 0.011 RUSLE Project; C23ONONC; Onions, Fresno CA Conventional Tillage ( USDA, 2000) USLE C Factor ( USLEC) 0.521  0.732 RUSLE Project; C23ONONC; Onions, Fresno CA Conventional Tillage ( USDA, 2000) Ciervo Soil Parameters Total Soil Depth ( CORED) 150 cm Number of Horizons ( NHORIZ) 3 ( Base horizons) NRCS, National Soils Characterization Database ( NRCS, 2001)