Phosphorus Fertilization Strategies for Alfalfa Hay Production followed by Corn Harvested for Grain
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.