Southeast Research and Demonstration Farm
Producers in southeast Iowa are interested in managing available soil phosphorus (P) and potassium (K) to achieve optimum grain yields. This study was established in 1989 to examine P and K management in a corn-soybean crop rotation. In 2001, a nitrogen (N) treatment was added to supply this nutrient to corn at moderate and high rates to determine if corn yields were affected by P and K management.
Iowa State University
Doorenbos, Russell and Henning, Stanley, "Crop and Soil Responses to Phosphorus and Potassium" (2003). Iowa State Research Farm Progress Reports. 1536.