Nitrogen Fertilization Effects on Corn Cellulosic Components and Ethanol Yield.

Research results on the effects of N management on corn (Zea mays L.) grain production in high-yielding cropping systems are widely available, but information on its effects on cellulosic composition and  ethanol potential from corn stover and cobs is limited. Stover and cob biomass and respective ethanol yields all increased as N fertilizer rate increased. However, the magnitude of their responses and their interaction with tillage system were dependent on the plant fraction. In general, the responses of stover characteristics were often more responsive than cobs. The results suggest that stover ethanol yield, which is the dominant fraction of total cellulosic ethanol, can be maximized at N fertilizer rates that are less than the economically optimum N rates (EONR) for grain yield. This is important because N fertilizer rates will not require adjustment to maximize theoretical cellulosic ethanol yield potential on an aerial basis. While cob ethanol yield may not be consistently maximized at the EONRs for grain yield, any potential losses should be relatively minor.