By Dan Looker
ANKENY, Iowa (IAWA) – In 2007, a group of Iowa State University researchers started testing the concept of mixing the advantages of tallgrass prairie with row crops, an effort they dubbed “Science-based Trials of Rowcrops Integrated with Prairie Strips,” or STRIPS.
One advantage prairie plants have is their roots, which reach up to 10 feet into the soil, deeper than those of cover crops. Prairie grasses also have thicker stems than cool-season grasses typically planted in waterways. So, small prairies excel at capturing runoff in a field or at its edges.
The scientists chose the 6,400-acre Neal Smith National Wildlife Refuge for trials. The refuge is the nation’s largest restored tall grass prairie, but it still has corn and soybean fields that offer whole watersheds unbroken by roads. There, researchers could measure nutrients and soil trapped by strips of prairie.
During the research trials, the scientists compared the conservation impact four land use types:100% row crop; 90% row crop with 10% prairie at the bottom of a watershed; 90% row crop with 10% prairie planted across and at the bottom of a field, and 80% row crop with 20% prairie across and at the bottom.
The sweet spot for soil and water conservation benefits ultimately was about 10% prairie and 90% crop, with no decreased yields in the cropped part of the field and no increased weed pressure. The first decade of research showed that prairie strip benefits include:
- 37% less water runoff
- 95% less soil loss
- 77% reduction in phosphorus runoff
- 70% reduction in both nitrate runoff and subsurface nitrates
Since that first STRIPS trial , ISU has expanded its research to other farms and locations across Iowa and northern Missouri. Michigan State University is conducting similar research in the eastern Corn Belt and the Sand County Foundation is researching prairie strips in Wisconsin.
In 2021, ISU professor of natural resource ecology and STRIPS co-founder Lisa Schulte Moore, was named a McArthur Fellow. The award, also called a “genius grant,” goes to scientists, artists, entrepreneurs and others with exceptional creativity and promise. Schulte Moore is the first ISU faculty member to receive a McArthur Fellowship.