Iowa is losing agricultural soil at alarming rates according to a new report conducted by the U.S. Department of Agriculture’s Natural Resource Conservation Service. Dr. Rick Cruse, Agronomy professor from Iowa State University who conducted the research says the goal of the project was to see how erosion varies across the state and with time. Provisions in the 1985 farm bill require farmers who accept crop subsidies to implement soil conservation measures on their most vulnerable cropland, but this report shows that enforcement has decreased.
Dr. Cruse says what has been learned is that certain parts of the state have experienced a high erosion rate which has caused significant damage. While most townships in Washington County averaged 0-5 tons of topsoil lost per acre per year, the townships of Dutch Creek, Iowa, Highland, Marion and Crawford showed greater losses in the ranges of 5.1 -10 tons of topsoil lost per acre per year.
Of the counties surrounding Washington County, Keokuk and Jefferson Counties showed the worst rates of erosion, each with three townships with topsoil losses in the range of 10.1 to 20 tons of topsoil lost per acre per year. The worst erosion in Iowa occurs in the southwestern part of the state. The results from this study show that one badly timed storm event, when the land is bare and vulnerable can sweep tons of topsoil off the landscape and into our waterways which can rob our land of its fertility at rates that exceeded its capacity to regenerate and will ultimately leave it unproductive.
One simple and effective soil conservation technique is to use buffers or strips of grass or trees within or along the edges of crop fields. To see more about this study, look here.