Biofuel Production and Water Quality: Challenges and Opportunities.

Biofuel production, particularly grain-based ethanol, is expanding rapidly.  Although subsidized grain-based ethanol may provide a competitively priced transportation fuel, concerns exist about potential water quality impacts.  Increased corn acreage and increased fertilizer application rates will increase N and P losses to streams, rivers, lakes, and coastal waters, particularly the Northern Gulf of Mexico and Atlantic coastal waters downstream of expanding production areas.  These losses may be exacerbated by heavy rains, such as in the Mississippi River Basin in 2008, highlighting the critical need for a broad suite of conservation measures, such as intensive nutrient management (e.g., application timing, rate, method, and use of stalk nitrate test) of new or more intensively managed corn lands, particularly under continuous corn production.  Drainage management, buffer and wetland creation are options to mitigate off-site impacts.  Dried distiller’s grains remaining after ethanol production from corn grain are used as animal feed and can increase manure P and N, which would increase the land base needed for sustainable land application.  Cellulosic fuel-stocks from perennials, such as switchgrass and woody materials, have the potential to produce bioenergy either through producing ethanol or other liquid fuels or through direct combustion to co-generate heat and electricity.  These uses of cellulosic renewable energy could provide multiple ecosystem services that include energy, carbon sequestration, and improved water quality.  Several Freshwater Initiatives are being developed by Federal and NGO’s to address broader issues facing water quality in the Mississippi River Basin that will impact biofuel production.  These Initiatives encourage redesign the agricultural landscape by using buffers and/or wetlands wherever intensive row crops are grown and to make perennial-based cellulosic ethanol economically viable so perennials can be grown on both productive and marginal lands.