Across the Dakotas and Nebraska, more than 1 million acres of the Great Plains are giving way to cornfields as farmers transform the wild expanse that once served as the backdrop for American pioneers.
This expansion of the Corn Belt is fueled in part by America's green energy policy, which requires oil companies to blend billions of gallons of corn ethanol into their gasoline. In 2010, fuel became the No. 1 use for corn in America, a title it held in 2011 and 2012 and narrowly lost this year. That helps keep prices high.
"It's not hard to do the math there as to what's profitable to have," Malsam said. "I think an ethanol plant is a farmer's friend."
What the green-energy program has made profitable, however, is far from green. A policy intended to reduce global warming is encouraging a farming practice that actually could worsen it.
That's because plowing into untouched grassland releases carbon dioxide that has been naturally locked in the soil. It also increases erosion and requires farmers to use fertilizers and other industrial chemicals. In turn, that destroys native plants and wipes out wildlife habitats.