EAST LANSING, MI. – Maximize your economic returns from phosphorus and potassium fertilizer applications to soybeans.

The keys to maximizing the economic returns from phosphorus (P) and potassium (K) fertilizer applications are a comprehensive soil testing program including a current soil test, and maintaining phosphorus and potassium soil test levels above their respective critical concentrations. The critical concentration for a given nutrient is the soil test level at which 95 to 97% of the crop’s yield potential will be reached without additional inputs of the nutrient.