Northern Research and Demonstration Farm
A long-term experiment was conducted to evaluate phosphorus (P) fertilization strategies for alfalfa grown for hay and followed by corn harvested for grain.Alfalfa has greater P requirements than corn, and this is recognized in the ISU Extension publication PM-1688. The guidelines are based on previous research with pure alfalfa or alfalfa-grass mixtures. The information available is about 30 years old; however, there is insufficient information about alternative strategies for distributing P fertilization rates during the alfalfa crop years and for a following corn crop. This study evaluated several combinations of initial and top-dressed P fertilization rates for alfalfa and also evaluated effects of starter P and nitrogen (N) on corn following alfalfa.
Iowa State University
Mallarino, Antonio P. and Rueber, David, "Phosphorus Fertilization Strategies for Alfalfa Hay Production followed by Corn Harvested for Grain" (2010). Iowa State Research Farm Progress Reports. 411.