SIMULATING THE EFFECTS OF EROSION ON CORN PRODUCTIVITY

Soil erosion effects on corn (Zea mays L.) production are sparsely doc umented for the Corn Belt. Simulation of these effects would help iden tify important information gaps for the region and elsewhere and help in the understanding of basic soil-plant processes and interactions th at occur. The N Tillage Residue Management model was tested on nine fi eld sites across the north-central USA. The 119 site-years of data sim ulated 78% (R(2) of 0.78) of observed corn yield variability for a wid e range of eroded soils. Slightly better predictions were made (R(2) v alues of 0.82 and 0.80) for loess-derived soils and soils in the easte rn (wetter) study areas, respectively. Till-derived soils and soils in the western (drier) areas had I values of 0.75 and 0.77, respectively . Crop yield predictions were most responsive to sell physical propert ies.