Rate and Timing of P and K Fertilization in Corn-Soybean Rotations in Minnesota


Start Date: 2011

Principal Investigator: Daniel Kaiser

Organization: University of Minnesota, Department of Soil, Water and Climate

Status: Complete

Background Information:

In corn-soybean rotations, most farmers apply fertilizer before the corn. However, in cases of high-pH soils, some producers also may apply fertilizer before the soybeans. Corn yield potentials have dramatically increased in the past 10 years, while soybean yields have remained fairly stable. This has caused some soybean growers to wonder if fertilizer should be directly applied to soybeans.


More research needs to be conducted focusing on phosphorus (P) and potassium (K) rates, as well as management and timing of applications with regard to crop yields and soil test changes. A research study was initiated in 2009 focusing on a corn and soybean system with multiple rates of P or K applied either before corn, soybeans or as a split application before both crops.

 Key Findings:


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