U.S. scientists say they have determined growing more corn to produce biofuels would contaminate water sources.
Purdue University researchers said their study of Indiana water sources found those near fields that practice continuous-corn rotations had higher levels of nitrogen, fungicides and phosphorous than corn-soybean rotations.
“When you move from corn-soybean rotations to continuous corn, the sediment losses will be much greater,” Associate Professor Indrajeet Chaubey, who co-led the study, said. “Increased sediment losses allow more fungicide and phosphorous to get into the water because they move with sediment.”
The researchers said nitrogen and fungicides are more heavily used in corn crops than soybeans, increasing the amounts found in the soil of continuous-corn fields.
U.S. Department of Agriculture data show corn acreage has increased with the demand for ethanol to 93 million acres 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 bio-feedstock, we would see more corn acreage being planted,” study co-leader Professor Bernard Engel said. “We need to know how that will affect water quality.”
The study appears in the early online version of The Journal of Environmental Engineering.