The Erosion-Productivity Index Simulator (EPIS) model is designed to provide the link between the Erosion-Productivity Index Calculator/Resource Conservation Act (EPIC/RCA) model and the RCA Information System. The EPIS model was used to expand 12,000 EPIC simulations into a data base of 250,000 resource/crop/tillage/conservation alternatives, to estimate the relative productivity among these alternatives, and to quantify the effect of erosion on productivity and fertilizer requirements.