Ag Engineering/Agronomy, Central Iowa and BioCentury Research Farms
Considerable research has been conducted in central Iowa to study potassium (K) fertilization rates and placement methods on corn and soybean grain yield, K uptake, and soil-test K values. However, no research has investigated K recycling to the soil by maturing plants and crop residue until the next crop is planted. The amount and the timing of the K recycled to the soil should have a significant impact on soil-test K values, and should explain a great deal of usually very high soil-test K temporal variability. Therefore, plots of several field K trials in central Iowa were used to investigate these issues.
Iowa State University
Mallarino, Antonio P.; Oltmans, Ryan R.; and Fiscus, Michael W., "Potassium Effects on Yield of Corn and Soybean and on Potassium Uptake and Recycling to the Soil" (2013). Iowa State Research Farm Progress Reports. 1877.