On Thursday, April 2, a research team from the University of Wisconsin published a new study revealing the conversion of 7.34 million acres of uncultivated land to cropland between 2008 and 2012. The researchers focused on land that had not been cultivated during the eight years preceding the conversion.

“In the US Corn Belt (supplementary figure S3) South Dakota and North Dakota experienced the greatest amount of new cultivation (supplementary table S2),” the authors state. “Here, expansion occurred primarily east of the Missouri river, especially concentrated in the Prairie Pothole Region, reinforcing the importance of previous studies focused on this region [12, 13]. Croplands also substantially infilled the lesser-cultivated areas of Southern Iowa and Northern Missouri, a region characterized by steeply sloped hills normally reserved for livestock grazing. In western Kansas and the panhandles of Oklahoma and Texas, we found highly concentrated expansion hotspots, many of which are indicative of new, center-pivot irrigated fields (supplementary figure S4).”

The most common source of land for new conversions to crop production is grassland, which accounted for 77 percent (5.7 million acres) of all conversions between 2008 and 2012. Roughly 28 percent (1.6 million acres) of these grassland acres had been in place for at least 20 years. The study’s geospatial analysis reveals that up to 42 percent of converted acres over this period may have come from land exiting the Conservation Reserve Program (CRP). The most common crops planted to converted land during the study period were corn, wheat, soy, and alfalfa.

The U.S. Department of Agriculture (USDA) is currently in the process of implementing several provisions of the 2014 Farm Bill aimed at protecting the conservation values of uncultivated land. These include: (1) a new 2 million acre grassland enrollment option through the Conservation Reserve Program; (2) a requirement that producers protect wetlands in exchange for farm subsidies; (3) a reduction in crop insurance premium subsidies on any acres that farmers convert from native sod to cropland (though the provision applies only in the northern Plains, not in the Kansas, Oklahoma, and Texas hotspots revealed in the new study); and (4) the Agricultural Conservation Easement Program, which establishes long-term easements to protect grasslands and wetlands.