ARS | Publication request: Biofuel potential of cellulosic double crops across the U.S. corn-soybean belt

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 15, 2011
Publication Date: May 15, 2011
Citation: Gamargo, G.G., Feyereisen, G.W., Baxter, R.E., Baker, J.M., Richard, T.L. 2011. Biofuel potential of cellulosic double crops across the U.S. corn-soybean belt [abstract]. 6th Frontiers in Bioenergy. Purdue University. West Lafayette, IN. Poster No. 11.

Technical Abstract: Interest in renewable energy sources derived from plant biomass is increasing, raising concern over fuel versus food competition. One strategy to produce additional cellulosic biomass without reducing food-harvest potential is to grow winter cover crops after harvest of the primary summer crop. This study estimates biomass accumulation of a fall-planted winter rye double crop across the United States on corn – soybean croplands. We identify corn and soybean acreages by county using USDA NASS data, excluding irrigated land and acreage already supporting a winter small grain crop. We calculate biomass production after corn harvest and prior to the subsequent corn or soybean crop for 30 locations within the identified region with RyeGro, a cover crop simulation model. Average RyeGro biomass yields for a 23-year period are used to develop a regression model based on temperature and precipitation. The regression model is then used to determine rye biomass potential in each county. The spatial analysis indicates that 18.4 million ha in continuous corn and 78.2 million ha in a corn-soybean rotation are suitable for producing winter rye. The average RyeGro biomass yield for the 30 locations for six planting-harvest date scenarios is 6.0 Mg ha-1. The modeling results project that from 194 to 224 million Mg of rye biomass, with an energy content of 3400 to 3900 PJ, can be harvested from this land base seven to two days prior to spring crop planting, respectively. The study demonstrates the sizable potential for this strategy to produce cellulosic biofuel without redirecting the primary food crop to fuel.