A new study in the journal Earth’s Future led by the University of Massachusetts Amherst shows that, since Euro-American settlement approximately 160 years ago, agricultural fields in the midwestern U.S. have lost, on average, two millimeters of soil per year. This is nearly double the rate of erosion that the USDA considers sustainable. Furthermore, USDA estimates of erosion are between three and eight times lower than the figures reported in the study. Finally, the study’s authors conclude that plowing, rather than the work of wind and water, is the major culprit.
“A few years back, my wife and I were at a wedding at a pioneer Norwegian church in Minnesota,” says Isaac Larsen, professor of geosciences at UMass Amherst and one of the paper’s co-authors. “After the ceremony, I walked over to the edge of the churchyard, which was surrounded by cornfields, and was shocked to see that the surface of the field was a few feet lower than the surface of the never-tilled churchyard. I began to wonder why.”
Fast forward a few years, and Larsen, along with the paper’s co-lead authors, Evan Thaler, who completed the research as part of his Ph.D. at UMass Amherst, and Jeffrey Kwang, a postdoctoral researcher at UMass Amherst at the time of the study, found himself standing in central Iowa on the “escarpment,” or drop-off, separating a native prairie from a field of soybeans.
Read more at: University of Massachusetts Amherst
UMass Amherst geosciences professor Isaac Larsen standing on the erosional escarpment at Stinson Prairie, Iowa. (Photo Credit: UMass Amherst)