Residue Management and Nitrogen Response in Continous Corn
Emerson D. Nafziger
There has been recent interest in producing ethanol from crop residues to reduce U.S. reliance on imported fossil fuels. In the Midwest, corn residue remaining after grain harvest is one of the most abundant sources of crop residue. If corn residue removal for ethanol production will occur, we believe that it will preferentially occur in fields where corn is grown continuously and not in rotation with soybean, since corn residue is a source of inoculum for many corn diseases. Furthermore, corn residue has a high carbon to nitrogen ratio, thereby favoring N immobilization. It is therefore possible that when corn is grown continuously, removal of corn residue may reduce the economic optimum nitrogen rate.