Iowa researchers study how prairie strips can boost soil health
Prairie strips are narrow bands of perennial, herbaceous vegetation strategically planted within crop fields. Studies have demonstrated their benefits for erosion control, water quality and wildlife habitat.
However, their impacts on soil health were not well documented until Iowa State University scientists conducted a comprehensive study. They examined 15 sites encompassing a range of Iowa landforms, each consisting of a prairie strip (between 2 and 13 years old) and a conventionally managed crop field in a corn-soybean rotation. They measured six soil health indicators in the top 6 inches of the soil. An in-depth, complementary assessment was conducted on a 12-year-old prairie strip at the Neal Smith National Wildlife Refuge in partnership with the Soil Health Institute.
Results showed that prairie strips can significantly improve soil health metrics within a decade. Perennial vegetation increased soil aggregate stability by up to 80%, boosted microbial biomass by as much as 54%, raised soil organic matter by up to 23% and enhanced water holding capacity by up to 7%. Additional related studies have found that these benefits extend beyond the strips themselves, influencing microbial activity, nutrient cycling and soil moisture up to 3 feet into adjacent cropland — with little impact on crop yields.
These findings show that prairie strips provide a relatively quick, practical strategy for rebuilding soil health and assuring the long-term sustainability of Midwestern crop fields.
Iowa Agriculture and Home Economics Experiment Station | Project supported by USDA Capacity – Research; non-profit grants and contracts. Photo courtesy of STRIPS Program/Iowa State University.
