How the Midwest's Corn Farms Are Cooking the Planet

—By Tom Philpott

I’ve been thinking a lot recently about how fertilizer from the Midwest’s big corn farms seeps into streams and causes trouble—fouling water supplies in Columbus,Toledo, Des Moines, and 60 other towns in Iowa, and generating a Connecticut-sized dead zone at the heart of the continental United States’ most productive fishery, the Gulf of Mexico. (Farms in the region also plant soybeans, but corn is by far the bigger fertilizer user.) But there’s another way the Corn Belt’s fertilizer habit damages a common resource: by releasing nitrous oxide (N2O), a greenhouse gas with nearly 300 times the heat-trapping power of carbon dioxide.

It turns out that the region’s farms are likely generating much more nitrous oxide than scientists previously thought, according to a new peer-reviewed study by a team of researchers from the University of Minnesota, Yale, and the US Department of Agriculture.