Grain-based ethanol production has increased dramatically in recent years as the cost and instability of oil has increased. New U.S. government policies require major increases in ethanol production. While future plans call for a viable cellulosic ethanol industry, expanded grain ethanol production will lead to further growth of corn acres in the near term, with unintended negative water quality impacts. Currently, U.S. grain-based ethanol production is concentrated in the Corn Belt; however, several large production plants are under construction or planned near population centers in the eastern U.S. An interdisciplinary group of scientists evaluated potential impacts of grain- and cellulose-based ethanol on nutrient and animal management as they relate to water quality impacts on U.S. inland and coastal waters, particularly the Northern Gulf of Mexico (Mississippi River Basin discharge). The results of their evaluation were published in the MarchApril issue of the Journal of Environmental Quality and were also considered in the U.S. EPA Scientific Advisory Boards 2007 Hypoxia Advisory Panels report.
The group of scientists recommended rigorous implementation of advanced conservation measures to minimize N and P losses from new or more intensively managed corn to partially offset nutrient loss increases. These measures include precision and variable rate applications of fertilizers, inter-seeding corn with cover crops, and inclusion of buffers or riparian filter strips. A viable perennial grass, wood, or waste-based cellulosic ethanol industry could provide water quality benefits and other ecosystem services. Regardless of feedstock, policy and scientific decisions must consider and address unintended consequences of biofuel production on the environment, particularly water quality, to avoid higher, future costs of remediation and ecosystem restoration.
Corn prices nearly doubled between 2005 (about $2.25 a bushel) and 2007 (about $4 per bushel;
|Contact: Sara Uttech|
Soil Science Society of America