1. Determining Cropping System and Topsoil Depth Effects on Phosphorus and Potassium Nutrient Dynamics

Understanding the effects of fertilizer addition and crop removal on long-term change in soil test phosphorus (STP) and soil test potassium (STK) is crucial for maximizing the use of grower inputs on claypan soils. Due to variable topsoil depth, nutrient supply from subsoils, and crop removal across fields, accurate P and K fertilizer management can be challenging. Current Missouri fertilizer recommendations rely on a single buffering capacity for all soils throughout the state for P, and are only...