In EPIC, the major biophysical processes simulated are called components. Runoff, percolation, lateral subsurface flow, and snow melt are simulated. Any one of four methods can be used to estimate potential evapotranspiration.
EPIC simulates soil erosion caused by wind and water.
Nutrients can be applied as mineral fertilizers, in irrigation water, or as animal manures. It is computed daily in each soil layer. The user may change the characteristics of simulated tillage equipment, if needed. Crop-specific parameters are available for most crops. The user may adjust or create new sets of parameters as needed.