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.
It appeared so damaging that scientists warned that America's corn-for-ethanol policy would fail as an anti-global warming strategy if too many farmers plowed over virgin land.
The Obama administration argued that would not happen. But the administration didn't set up a way to monitor whether it actually happened.
It did.
More than 1.2 million acres of grassland have been lost since the federal government required that gasoline be blended with increasing amounts of ethanol, an Associated Press analysis of satellite data found. Plots that were wild grass or pastureland seven years ago are now corn and soybean fields.
That's in addition to the 5 million acres of farmland that had been aside for conservation - more than Yellowstone, Everglades and Yosemite National Parks combined - that have vanished since Obama took office.
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