, Top Producer Editor
A controversial study out of Purdue University suggests that more of the fertilizers and pesticides used to grow corn would find their way into nearby water sources if ethanol demand leads to more corn acres.
The study of Indiana water sources found that those near fields that practice continuous-corn rotations had higher levels of nitrogen, fungicides and phosphorus than those near fields with corn–soybean rotations. Results of the study by Indrajeet Chaubey, a Purdue associate professor of agricultural and biological engineering, and Bernard Engel, Purdue professor and head of agricultural and biological engineering, were published in the Journal of Environmental Engineering.
"When you move from corn–soybean rotations to continuous corn, the sediment losses will be much greater,” Chaubey says. "Increased sediment losses allow more fungicide and phosphorus to get into the water because they move with sediment.”
Sediment losses become more prevalent with corn crops because tilling is often required in continuous-corn fields, whereas corn–soybean rotations can more easily be no-till fields, Engel says.
USDA data has shown that corn acreage has increased with the demand for ethanol, with 93 million acres of corn in 2007, an increase of 12.1 million acres that year.
"As we look forward here, if corn stover is going to be a preferred biofeedstock, we would see more corn acreage being planted,” Engel says. "We need to know how that will affect water quality.”
USDA and Purdue funded the study. Chaubey and Engel are expanding their research to Iowa, Tennessee and Arkansas.