The Loss of Our Nation's Topsoil, Visualized

The breadbasket has lost over half its topsoil. It's time to reign in federal policies that are stripping our nation's most valuable natural resource.

Iowa is washing away.

Each spring, flooding on the Mississippi River takes tons of soil and nutrients downstream, and farmers across the Midwest—where the bulk of food in the United States comes from—replace that lost fertility with synthetic nitrogen fertilizers. There's no quick replacement for all that topsoil.

Over the last 150 years, the native tall-grass prairies here have lost 8 to 10 inches of topsoil, more than 50 percent, and the region appears to be losing soil faster than anticipated, according to a new report from the Environmental Working Group.

In Adair County, Iowa, state highway officials installed these five pillars at a rest area off Highway 80. They're designed to visualize the incremental losses of topsoil over time, showing the diminished height of soil and native vegetation.

It's a small reminder, but one more of us should see.

We need to pay attention to the next Farm Bill, which will develop farm programs that could emphasize better soil conservation, rather than creating incentives to plant more. As The New York Times put it in an incisive op-ed, "Erosion is not nature or bad farmers at work. It is the legacy of bad agricultural policy."

Image: David B. Dahlquist RDG Art Studio, via Maggie Koerth-Baker.