Research from Iowa State University indicates that prairie strips can significantly enhance soil health more rapidly than previously anticipated. Collaborating with the Soil Health Institute, scientists found that these strips—comprised of 30 to 100 feet of herbaceous, perennial plants integrated within crop fields—can restore essential benefits of Iowa’s native prairies while minimally impacting agricultural output.
The study, published in the Journal of Soil and Water Conservation, highlights that prairie strips established for about 10 to 12 years have improved eight out of twelve indicators of soil health. Key improvements include a remarkable increase in soil aggregate stability, microbial biomass, soil organic matter, and maximum water-holding capacity, with some metrics showing gains of up to 80%, 54%, 23%, and 7%, respectively.
Significant Findings on Soil Health Improvement
Marshall McDaniel, an associate professor of agronomy at Iowa State and the study’s coordinator, expressed his surprise at the rapid changes observed. “It was an exciting surprise to see the degree of these changes over just a decade,” he stated. Historically, it was believed that such transformations would take much longer, particularly regarding soil organic matter and water retention.
The research employed a “paired chronoscope” approach, comparing 15 paired sites featuring prairie strips ranging from 2 to 13 years old against conventional cropland. This method allowed for a robust analysis of soil health across four of Iowa’s seven major landforms, with most sites located on private farmland.
Six aspects of soil health were measured within the top six inches of soil. A more detailed assessment was performed along a 12-year-old prairie strip at the Neal Smith National Wildlife Refuge in Prairie City, led by Elizabeth Riecke from the Soil Health Institute.
Broader implications of the study were also noted. Lead author Cole Dutter, who recently completed his doctorate in sustainable agriculture and soil science, reported significant changes in microbial communities extending from the prairie strips into adjacent cropland. These shifts included elevated enzyme levels that enhance nutrient cycling and carbon storage, potentially leading to better nutrient availability for crops.
Future Directions and Farmer Involvement
The research reveals that the benefits of prairie strips can extend beyond their immediate location, affecting soil moisture and nutrient availability up to one meter outward, all while maintaining crop yields. Farmers have expressed interest in rotating their prairie strips every ten years to maximize benefits across their fields. Lisa Schulte Moore, director of ISU’s Bioeconomy Institute and a collaborator on the project, noted ongoing research into this concept, which appears to yield long-term soil health and crop productivity benefits.
As Dutter transitions to a faculty position at California State University, Stanislaus, he aims to continue researching prairie strips, emphasizing their potential for enhancing soil health throughout agricultural fields. He remarks, “We think there is a lot of potential to expand these benefits throughout fields and even improve yields.”
The study also highlights accessible methods for measuring soil health, including DIY tests that landowners can conduct. McDaniel pointed out that simple tests for aggregate stability can be performed using a smartphone app called Slakes, while the maximum water-holding capacity can be measured with basic household items, such as a funnel and coffee filter.
Funding for the research 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.
In summary, this research demonstrates the quick and effective benefits of prairie strips in enhancing soil health, offering a promising avenue for sustainable agricultural practices that could lead to improved environmental conditions and crop yields.
