Editor’s note: This article is the second in a three-part series featuring research projects designed to help farmers enhance productivity and environmental quality in a changing climate. The topic also was the theme of the recent annual meeting of the American Society of Agronomy and Crop Science Society.
While there’s debate about what’s causing more frequent severe-weather events, Wisconsinites would agree that excessive rainfall in 2018 caused serious flooding damage. Even in areas that weren’t flooded, pounding rain resulted in sediment loss and nutrient runoff on many a farm field.
Seeing the detrimental effects of such rainstorms, more farmers are adding new tools to their “toolboxes.” Prairie strips are among those tools. And 10 years’ worth of on-farm research findings by Iowa State University researchers indicates prairie strips are working. The Iowa State testing program began in 2007 on 2- to 12-acre parcels. The program has since been expanded to larger parcels.
Results from a decade of testing show that converting just 10 percent of a crop field to prairie strips could help farmers reduce runoff of water by 44 percent, sediment by 95 percent, phosphorus by 90 percent and nitrogen by 84 percent. The areas tested were all on corn and soybean farms.
Testing and monitoring have been conducted on 43 farms in Iowa and northern Missouri as of 2018. Fourteen of the farms are currently in the process of integrating prairie strips into their production programs, said Lisa Schulte-Moore, a professor in the natural resource-ecology and management department at Iowa State University. Moore also is co-leader of the Science-based Trials of Rowcrops Integrated with Prairie Strips project, known as STRIPS.
“We’re working to understand the impacts of prairie strips on yield, soil, water, soil-microbe activity, birds, mammals, snakes and pollinators,” she said.
The project researchers have found that prairie strips have encouraged a 3.5-fold increase in pollinators and a 2.1-fold increase in bird species. The strips are composed of about 30 species. The native-species mixes are comprised primarily of wildflower species and between three to five grass species, Schulte-Moore said.
“Our goal is to have something in bloom throughout the growing season to support pollinators,” she said.
Schulte-Moore and her colleagues also work with farmer-cooperators on prairie-strip designs to meet farmer goals. Some farmers are focused on slowing water movement and keeping soil in place. Others are focused on keeping their farms “farmable,” or making it easy to maneuver farm equipment in fields with prairie strips. Others consider using prairie strips on poorer-yielding areas on their land.
Matthew Helmers, an associate professor of agricultural and biosystems engineering as well as an Iowa State University-Extension agricultural engineer, said prairie plants – with their stiff upright stems and deep roots – slow water flow and encourage infiltration. That helps hold soil and nutrients in the field. Diverse prairie strips are able to withstand drought and intense rain, according to “Iowa State University Prairie Strips Study Yields Options to Improve Conservation,” published by Iowa State University’s College of Agriculture and Life Sciences.
“Prairie strips would rank among the least expensive in-field management practices, costing about $40 per treated acre per year for establishment and management,” Helmers said.
Mowing is important during the establishment phase to keep at bay annual weeds, Schulte-Moore said. Depending on the situation, a farmer may need to mow the prairie strip two to four times the first year. That may be followed in the second year with one or two cuttings. By the third year mowing likely wouldn’t be necessary.
Farmers in Wisconsin also are beginning to experiment with prairie strips. Sand County Foundation is working with six farmers to test how prairie strips work on farms with different soil types, topographies and management practices. Sand County Foundation is working on the project in cooperation with the University of Wisconsin’s Center for Integrated Agricultural Systems and the Valley Stewardship Network.
The Valley Stewardship Network is working with Fishers and Farmers, the Sand County Foundation, North Central Region Sustainable Agriculture Research and Education, The Pasture Project and the Wallace Center at Winrock International as well as farmers and landowners to establish prairie strips adjacent to crop fields in Wisconsin’s Kickapoo River watershed and surrounding watersheds. A limited amount of funding from Fishers and Farmers is available to increase the amount of prairie seed available to local farmers to establish prairie-conservation strips. Fishers and Farmers also offers technical assistance at no charge.
Visit www.nrem.iastate.edu/research/STRIPS or sandcountyfoundation.org or contact firstname.lastname@example.org or 608-663-4605 ext. 22, or visit valleystewardshipnetwork.org or contact 608-637-3615 for more information.
The first article in the series, “Bacteria eat nitrates in runoff,” was published in the Dec. 6 issue of Agri-View.