This is an excerpt from EERE Network News, a weekly electronic newsletter.

December 10, 2008

Report: Improved Crops Would Help Meet Federal Biofuel Targets

A new report from the Biomass Research and Development Board finds that higher corn yields and improved energy crops could make it much easier to meet the federal Renewable Fuels Standard (RFS) in coming years. The RFS requires conventional ethanol production to increase to 15 billion gallons per year by 2016, and to meet that with current trends in corn yields would require a 4.1% increase in corn acreage. The good news is that the increase would be mostly accommodated by existing farmland in the areas that now grow most of the nation's corn, but the increased production would also cause a price increase that would cut non-ethanol corn use by 5.2% and reduce exports by 7.7%. Although the report did not examine international effects, such a cut in U.S. corn exports would presumably spur greater production in other countries, which could lead to land use changes that would impact greenhouse gas emissions. However, higher U.S. corn yields could ease these impacts. While the report assumes a yield increase of about 2 bushels per acre per year, an accelerated increase in corn yield of about 3.1 bushels per acre per year would mitigate most corn prices impacts, as well as the impacts of corn plantings on other crop production.

The RFS also requires the production of 20 billion gallons of advanced biofuels, such as cellulosic ethanol, by 2022. Cellulosic ethanol is produced from non-food biomass sources, such as corn stover (the stalks, leaves, and cobs from corn), wood chips, other agricultural residues, and energy crops such as straw, switchgrass, and poplar. Wood chips left over from wood product production and from forest fuels reduction are expected to supply about 4 billion gallons of cellulosic ethanol. That provides relief for farm-based feedstocks, holding their price to about $45 per ton versus $60 per ton without the wood chips. Agricultural residues would provide about 60% of the remaining 16 billion gallons, with corn stover comprising most of the residues, even though the report assumes that some corn stover will be left in place to maintain land quality. The remaining cellulosic ethanol will be produced from dedicated energy crops, including hay in the Northern Plains, the Mountain States, and the Pacific region, and other energy crops in the Corn Belt, the Southeast, Appalachia, and the Mississippi Delta. Most crops will probably be grown on pasture land or unproductive farmland, although some productive farmland will be shifted to energy crops, particularly in Arkansas, Louisiana, and Mississippi.

The report also examines the greenhouse gas (GHG) impacts within the United States of meeting the RFS requirements. It notes that the increase in corn production will boost agricultural GHG emissions by only 1.8%, the equivalent of about 8 million metric tons of carbon dioxide emissions, and a boost in corn yield could essentially eliminate that increase. However, the report does not account for international impacts or for secondary impacts on livestock production and feed production, nor does it take credit for reductions in petroleum consumption. The report does anticipate that a high price for fuel and a price of $25 per thousand tons of carbon dioxide emissions would encourage farmers to reduce their GHG emissions, and thus reduce the impact of growing the energy crops. The report concludes with a call for research on higher crop yields, on more sustainable farming methods, and on a broad portfolio of potential energy crops. It also calls for more data on energy crops and more rigorous models to examine the impacts of growing such crops on such factors as GHG emissions. The Biomass Research and Development Board is co-chaired by DOE and the U.S. Department of Agriculture (USDA), and is part of the Biomass Research and Development Initiative (BRDi), which involves six federal agencies and two executive offices. See the USDA press release and the full report (PDF 9.7 MB). Download Adobe Reader.

Features