WASHINGTON (December 16, 2020)—Unhealthy farming practices and more extreme weather spurred by climate change will lead to an increased rate of soil erosion across the United States in the coming decades, according to a study released today by the Union of Concerned Scientists (UCS). If soil continues to erode at current rates, U.S. farmers could lose a half-inch of topsoil by 2035—more than eight times the amount of topsoil lost during the Dust Bowl. They could lose nearly three inches by 2100. Given that it takes a century or more for an inch of soil to form naturally, the United States will lose the equivalent of at least 300 years’ worth of soil by 2100 if today’s trends prevail.
“Soil erosion is a natural process, but it has been vastly and needlessly accelerated by unsustainable agriculture practices in many regions across the United States and globally,” said Marcia DeLonge, author of the study and Food & Environment research director and senior scientist at UCS. “Healthy living soil is the foundation of our food system and as important to our well-being as clean air and water. It reduces erosion, promotes healthy crops and holds more water, making farmers and nearby communities less vulnerable to floods and droughts.”
Common farming methods strip soil of its nutrients and protective cover, making it vulnerable to erosion. When wind and water erosion deplete soil faster than it forms, the topsoil farmers rely on begins to disappear. Healthy living soil is soil filled with beneficial insects, fungi and microbes that recycle leaves and other material into organic matter and nutrients. It also serves as a natural carbon store to mitigate climate change.
The UCS study analyzed various scenarios for erosion rates and total soil loss using soil survey data from the National Resources Inventory, a research program conducted by the USDA and Iowa State University. Because of climate change, the possibility for even more accelerated erosion rates exists. The study found if more flooding and droughts lead erosion rates to worsen again, reverting back to the higher rates recorded almost forty years ago, farmers nationally are at risk of losing more than two inches of soil by 2035 and five inches by 2100.
“Erosion is not just about degrading farmland, it also is about soil and the excess fertilizer and other pollutants it takes with it running off into places where we don’t want it,” said Karen Perry Stillerman, co-author of the study and senior analyst at UCS. “We see this pollution from erosion and runoff everywhere from drinking water sources in Iowa, where it threatens public health, to many miles down the Mississippi River in the Gulf of Mexico, where it harms local fishing communities. Soil loss is so bad now, it’s painful to imagine the situation getting even worse.”
More sustainable farming practices include planting cover crops between cash crops, growing deep-rooted perennials, using conservation tillage or no-till farming, rotating diverse crops and better management of grazing lands, according to UCS. Such practices keep soil in place and build its ability to drain and hold water, increasing farmers’ resilience.
The study outlines several federal policies that could aid farmers and transform the agricultural industry, including supporting U.S. Department of Agriculture programs focused on reducing soil erosion, strengthening federal crop insurance to incentivize healthy soil practices and providing funding to states so they can advance their own regional programs.
“In addition to threatening the future of our food system, soil erosion is a burden to taxpayers who foot the bill for higher federal crop insurance payouts for preventable drought- and flood-related losses. It’s a no-brainer for governments to give farmers the tools they need to conserve and rebuild their soil,” said Stillerman.