Using farm waste for ethanol may hurt crop yields
July 15, 2008
Cellulosic ethanol proponents have pushed the idea of using farm waste as a way to boost biofuel production without impacting food crops, but such conversion may carry a hidden cost in areas with insufficient rainfall or lacking irrigation, warns a soil scientist from Washington State University.
Ann Kennedy, a USDA-Agricultural Research Service soil scientist and adjunct professor of crop and soil sciences at Washington State University, says that farm residues provide nutrients to crops, facilitate water retention in soils, and help prevent wind erosion. Removing these residues for ethanol production could adversely affect crop production, especially in dry areas.
“We need to constantly replenish organic matter—so removing valuable residue, especially in areas with low rainfall, may not be the best practice,” she said. “If residue were harvested soil fertility would drop and farmers would have to find other ways to increase the amount of organic matter in their soils.”