The most recent fertilizer phosphorus (P) and potassium (K) rate recommendations for corn and soybeans grown in Ohio were published in the mid-90s and follow the buildup, maintenance, and drawdown approach. Validation of recommendations using today's farming practices is needed. In this study, fertilizer P and K application rates estimated to equal or exceed crop removal were applied and resulting corn and soybean grain yield and soil test P and K trends were observed throughout nine years of production at three sites in Ohio.
Corn and Soybean Response to Phosphorus and Potassium Fertilization in Ohio