Crop Rotation Fertilizer Decisions Hinge on Nutrient Removal Rates

Farmers must carefully consider nutrient removal rates when developing fertilizer plans for future crop rotations. According to Michigan State University Extension, harvesting crops removes valuable nutrients from the soil, making it essential to account for nutrient removal during harvest and existing soil test concentrations.

Nutrient removal rates vary by crop and have changed over time as grain nutrient concentrations have declined. The 2020 Tri-State Fertilizer Recommendations show that corn removes approximately 52 pounds of phosphate (P2O5) and 30 pounds of potash (K2O) per acre, while soybeans remove around 39 pounds of phosphate and 56 pounds of potash per acre.

The revised fertilizer recommendation framework by Michigan State University Extension uses build and maintain categories, providing greater flexibility based on factors such as fertilizer prices and whether farmland is rented or owned. Fields with soil test phosphorus or potassium concentrations below critical levels require fertilizer applications sufficient to replace nutrients removed by crops and build soil nutrient concentrations.