Long-Term Potassium Fertilization Effects on Yield of Corn and Soybean in South Central Iowa
Extensive research has been conducted in Iowa to study the potassium (K) fertilization of corn and soybean, but not in south-central Iowa soils. Soil K deficiency decreases crop yield and economic benefits to growers. Also, research in other locations has shown that a K deficiency can reduce the capacity of corn to respond to nitrogen (N) and can increase the incidence of some soybean diseases. Therefore, a long-term K response study was initiated in 2009 at the McNay Research and Demonstration Farm to study corn and soybean response to K fertilizer.