EPIC MODEL PARAMETERS FOR CEREAL, OILSEED, AND FORAGE CROPS IN THE NORTHERN GREAT-PLAINS REGION

The EPIC computer simulation model has potential for assessing agricul tural management scenarios in the northern Great Plains region of the United States and western Canada. The objectives of this study were to develop parameters for economically important crop and forage species grown in these regions and to determine whether EPIC could use these parameters to reasonably simulate yields. Parameters for leaf-area dev elopment, temperature responses, biomass growth and partitioning, and nutrient concentrations were derived from data in the literature for s pring canola, wheat, barley, maize and six forage species. Because of the growing importance of canola in Canada and the United States, much emphasis was placed on deriving its parameters. With these inputs, EP IC reasonably simulated forage and crop yields in six locations and ca nola yields in four locations. The model should provide reasonable sim ulations for a wide range of applications throughout these regions.