Tuesday, November 6, 2007 - 10:00 AM
221-2

Nutrient Management Implications of Corn-Based Cropping Systems for Ethanol Production.

Tony Vyn, Purdue University-Agronomy Dept., Purdue Univ. Dept. of Agronomy, 1150 Lilly Hall 915 W State St., West Lafayette, IN 47907-1150, Daniel T. Walters, University of Nebraska, Dept. of Agronomy & Horticulture, 261 PLSH, Lincoln, NE 68583-0915, Achim Dobermann, International Rice Research Institute (IRRI), DAPO Box 7777, Manila, 1271, Philippines, and Paul Fixen, International Plant Nutrition Institute Headquarters, International Plant Nutrition Institute, 772-22nd Ave. S, Brookings, SD 57006.

The nutrient management implications of growing corn for ethanol depend on the associated cropping systems that farmers employ to take advantage of this growing demand.  The most relevant cropping system considerations for this discussion include crop sequence, corn harvest mode, tillage system, and the degree to which plant nutrients are derived from various types of livestock manure.  If only the grain is removed for eventual sale to ethanol plants, there is no change relative to normal cash grain production unless the intensity of corn in rotation changes.  As rotation systems become more corn-dominant, we can expect that optimum corn performance will require higher rates of both N and P relative to a corn-soybean system, and perhaps an adjustment in the optimum timing of N fertilizer application.  If corn stover is removed for cellulosic conversion to ethanol, adjustments in K fertilizer rates are an additional factor to consider.  Tillage systems for rotation corn versus corn after corn may also affect the net availability of essential nutrients.  Corn stover removal may enhance the feasibility of no-till corn.  However, these generalized soil nutrient implications when corn grain and stover are harvested for ethanol are fundamentally changed if these corn fields also receive manure from livestock whose diets include dried distillers grains (DDGs).   Beef cattle manure resulting from high-DDG diets has higher N and P concentrations than that from grain-based diets.  To a large extent, the opportunity to advance the overall energy efficiency and environmental sustainability of corn production systems for ethanol production depends on sound nutrient management research over the next decade.  Such research must be conducted in the context of integrated cropping systems involving the  various crop sequence, tillage, manure, and corn harvest modes that will enhance nutrient efficiency of corn production for our growing fuel, food and feed demands.

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Back to The ASA-CSSA-SSSA International Annual Meetings (November 4-8, 2007)