5.7M acres of U.S. grasslands plowed for crops over four years — study 

Source: Tiffany Stecker, E&E reporter • Posted: Monday, April 6, 2015

A new study finds that 7.3 million acres have been converted to cropland nationwide over the last four years.

The paper, published online today in the journal Environmental Research Letters, tracked land-use changes between 2008 and 2012 — a time of high corn and soybean prices and the onset of the federal renewable fuel standard. Of the more than 7 million acres plowed for crops, 5.7 million acres were grasslands.

While the authors of the paper don’t assign responsibility to any given policy for the conversion, U.S. EPA should enforce provisions in the RFS that protect grasslands, they argue.

“The RFS is permitting, rather than preventing, the conversion of these natural ecosystems,” said Tyler Lark, lead author of the paper and a graduate student at the University of Wisconsin, Madison. “The current monitoring scheme for that type of conversion is left unchecked.”

The authors used five years of data from the Agriculture Department’s cropland data layer, which culls its information from satellite. The researchers also used historical land cover information from two U.S. Geological Survey data sets. The most common crops to be first planted were found to be corn and soybeans.

While most studies on cropland change have centered around the Corn Belt, Lark and University of Wisconsin geography professor Holly Gibbs looked at all of the continental United States, yielding more interesting results. For example, two-thirds of land conversion occurred outside of the six states — North Dakota, South Dakota, Montana, Iowa, Minnesota and Nebraska — in which the 2014 farm bill instituted the “Sodsaver” provision, which requires farmers to preserve grasslands in order to be eligible for federal crop insurance subsidies. Hot spots of grasslands conversion include southern Iowa, northern Missouri, the Texas and Oklahoma Panhandle region, and western Kansas.

The study builds on a 2013 study published in Proceedings of the National Academy of Sciences titled “Recent Land Use Change in the Western Corn Belt Threatens Grasslands and Wetlands,” which was harshly criticized by the ethanol industry