Iowa Research Shows Prairie Strips Rapidly Enhance Soil Health
New research from Iowa State University has revealed that prairie strips can significantly enhance soil health more quickly than previously thought. Conducted in collaboration with the Soil Health Institute, the study indicates that these strips—30 to 100 feet wide and composed of herbaceous, perennial plants—improve soil health metrics within a decade, while minimally affecting crop production.
The research, published in the *Journal of Soil and Water Conservation*, found that prairie strips improved eight out of twelve measured indicators of soil health over a period of just 10 to 12 years. Specifically, the study highlighted remarkable increases in soil aggregate stability by up to 80%, microbial biomass by up to 54%, and soil organic matter by up to 23%. Additionally, the maximum water-holding capacity of the soil improved by up to 7%.
Marshall McDaniel, an associate professor of agronomy at Iowa State and the study’s coordinator, expressed enthusiasm about the findings. “It was an exciting surprise to see the degree of these changes over just a decade or so,” he stated. “It has been thought that it would take much longer to see some of these levels of change, especially in soil organic matter and maximum water-holding capacity.”
The research employed a “paired chronoscope” approach, comparing 15 pairs of control and treatment sites—each featuring prairie strips ranging from 2 to 13 years old. These sites represented four of Iowa’s seven major landforms, and most were located on private farmland. Measurements were taken from the top six inches of soil, with a more thorough assessment conducted at the oldest prairie strip (12 years old) at the Neal Smith National Wildlife Refuge near Prairie City.
The study’s lead author, Cole Dutter, who completed his doctorate in sustainable agriculture and soil science, noted that significant changes in microbial communities extended from the prairie strips into adjacent cropland, enhancing nutrient cycling and carbon storage. The effects reached beyond three feet (approximately one meter) into the cropland, with minimal impacts on crop yields.
As the research indicates, prairie strips can yield substantial benefits relatively quickly. Lisa Schulte Moore, director of Iowa State’s Bioeconomy Institute and a collaborator on the study, mentioned that some farmers are considering rotating their prairie strips after ten years to distribute these benefits across their fields. “Cole has initiated some interesting research looking at this idea,” she said, “showing some long-term boosts to soil health and crop yields from rotating strips within fields.”
Looking ahead, Dutter plans to continue his involvement in prairie strips research at California State University, Stanislaus. He emphasized the potential for prairie strips to build soil health effectively. “An area we need to learn more about is whether and to what degree that translates to storing carbon deeper in the soil profile,” he remarked.
The researchers also highlighted that the methods used to measure aggregate stability and water-holding capacity are accessible to non-scientists. According to McDaniel, “These DIY tests are great tools that landowners can use to assess soil health on their own fields after implementing management changes like prairie strips.”
The maximum water-holding capacity can be measured using simple materials like a funnel and coffee filter. Similarly, soil aggregate stability can be assessed with a smartphone app called Slakes, developed by the Soil Health Institute.
Funding for the study primarily came from the Foundation for Food and Agriculture Research and the USDA Farm Service Agency, with additional support from the National Science Foundation and USDA Hatch funds. This research marks a significant step in understanding the rapid benefits that prairie strips can provide to soil health, offering farmers a practical strategy for sustainable agricultural practices.
