Corn grown after alfalfa usually has increased yield, reduced nitrogen requirement from fertilizer or manure, and reduced pest pressure compared to when following other crops. The extent and consistency of these benefits in first- and second-year corn are influenced by the effectiveness of alfalfa termination and nitrogen management, says University of Minnesota corn specialist.
Strategies for successful alfalfa termination to fully achieve rotational benefits are summarized at http://z.umn.edu/rotation.
Nitrogen management guidelines for first- and second-year corn following alfalfa are available at http://z.umn.edu/fertilizingcorn. These guidelines, updated in 2016, no longer assign nitrogen credits to corn based on alfalfa stand density, and are based on factors such as soil texture, age of alfalfa at termination, and alfalfa termination timing.