Corn is marching northward in Minnesota, spurred in part by higher prices from the ethanol boom and by new varieties that mature before the frost sets in.
That means new opportunities for producers like Gary Purath, a fourth-generation farmer who grows corn, soybeans and wheat and raises Angus cattle near Red Lake Falls in northwestern Minnesota. It's a region where growing corn used to be too risky because of the early onset of winter, where previous generations of farmers might have played it safer with barley or oats.
But it also means land set aside for years in the federal Conservation Reserve Program sometimes gets plowed in favor of corn. That disturbs Dan Svedarsky, director of the Center for Sustainability at the University of Minnesota-Crookston, who has followed land use trends there for over 44 years. He said he has seen a "massive transfer" of erodible land in the region from conservation into corn and soybeans in just the past two years.
"People have become wealthy due to the boom in crop prices," he said. "That's a good thing. That's what drives our economy. But it has not come without a price."
That price includes not just water quality, as runoff carries topsoil and chemicals from fields that return to production, but water quantity as well. The additional drainage coming off those fields means more water flowing into the already flood-prone Red River Valley watershed, Svedarsky said.
Nitrogen and phosphorous eventually flow north into Canada's Lake Winnipeg, where they contribute to thick algae blooms that can be toxic.
As such consequences play out nationally, environmentalists and many scientists have concluded the costs of ethanol outweigh the benefits. The Obama administration has taken to highlighting ethanol's benefits to agriculture instead of pitching it as an environmental strategy for reducing greenhouse gases.