Stratification and Phosphorus Losses in Corn/Soybean Rotations.

Increased soluble P loading from row crop agriculture in the Western Lake Erie Basin has been blamed in part on P stratification that can occur in pure no-till systems. Plots were initiated with ten treatments, including various P fertilizer sources (diammonium phosphate, monoammonium phosphate, polyphosphate), P fertilizer rates (annual application or biennial application), fertilizer placement (surface broadcast or banded) and tillage (no-till or tilled) and cover crops. Fertilizer applications were made in the spring, followed by rainfall simulations. The results of three years of rainfall simulations will be presented and discussed.