Watch potassium management—It also effects corn response to nitrogen and soybean diseases

Potassium (K) fertilization effects on corn and soybean grain yield have been studied for many years in Iowa. Research results summarized for this and other conferences included calibration of soil-test methods and study of soil-test K spatial and temporal variability, recycling with crop residues, K placement methods for various tillage systems, soil sampling methods, and variable-rate fertilization. The research has shown the importance of proper K fertilization practices for profitable crop production, which mainly include appropriate use of soil sampling and testing, fertilizing low-testing soils, maintaining soil-test K levels in the optimum interpretation category, and avoiding fertilization of high-testing soils. However, recent or ongoing significant research with K has not been shared. This research relates to interactions of K fertilization with other inputs or growing conditions. This article summarizes results of research on the interaction of K with nitrogen (N) fertilization of corn and incidence of soybean diseases