Tilling farmland is a key contributor to erosion and has played a role in the loss of billions of tons of soil in the U.S. Midwest, a new study finds.
With soils rich for cultivation, most land in the Midwestern United States has been converted from tallgrass prairie to agricultural fields. Less than 0.1 percent of the original prairie remains.Earth’s Future
. “These rare prairie remnants that are scattered across the Midwest are sort of a preservation of the pre-European-American settlement land surface,” says Isaac Larsen, a geologist at the University of Massachusetts Amherst. Geologist Isaac Larsen stands at an erosional escarpment, a meeting point of farmland and prairie, in Stinson Prairie, Iowa. Studying these escarpments shows there’s been a startling amount of erosion in the U.S. Midwest since farming started there more than 150 years ago.This corresponds to the loss of roughly 1.9 millimeters of soil per year from agricultural fields since the estimated start of traditional farming at these sites more than a century and a half ago, the researchers calculate.