Read more about prairie STRIPS and other water quality successes in Working For Clean Water, the DNR's annual watershed success story publication.
“Conservation with a purpose” is how Tim Smith describes his newest farming venture that builds on past work to protect water quality on his Wright County farm.
Previous success with strip tillage and cover crops led Smith, located in the Boone River watershed, to meet with Seth Watkins, a Clarinda farmer who plants small strips of prairie to protect soil. Smith was immediately interested in STRIPS, or Science-based Trials of Rowcrops Integrated with Prairie Strips.
Results from seven years of research on the Neal Smith National Wildlife Refuge in Jasper County make a compelling argument: converting just 10 percent of a crop field to strategically placed prairie reduces runoff by 40 percent, soil loss by 95 percent, phosphorus loss by 90 percent and nitrogen loss by 84 percent. Additional benefits accrue for wildlife, plants and insects as compared to a cropped field.
Smith notes planting deep-rooted prairie grasses will improve water quality above and below ground. “It will keep soil from moving downslope, reducing phosphorus movement, and underneath, the root system intercepts nitrogen,” he says.
It’s the other add-on benefits—wildlife, plant diversity and resilience to changing weather, aesthetics—that make prairie strips so attractive to him. Smith’s plan calls for creating a wildlife corridor, using prairie strips to connect a field in permanent cover through the USDA Conservation Reserve Program with his brother’s recent tree plantings, while protecting a stream and filtering runoff from a crop field. Planting a diverse mix of 30 prairie species will make for a more sustainable system, as different plants thrive under different weather conditions.
He’s had some experience with the erosive power of severe rains in 2013 and when 13 inches of rain fell in two weeks in 2014. “From early May until the crop forms a canopy in late June or July, the soil is really exposed to rain unless you have practices in place to protect your soil from those intense rains,” he says. “Prairie strips are a very good alternative to terraces. Although you lose a certain amount of land, you gain a tremendous benefit.”
After growing up on a diversified farm near Williamsburg in Iowa County, landowner Lucena Morse has a passion for prairie, like her mother, who added prairie in the 1980s after reading Rachel Carson’s Silent Spring. With her siblings, Morse added to those original plantings with a diverse seeding of grasses and forbs planted on the contour, in a layout to make farming easy for their tenant’s tillage equipment.
“I’m so excited about STRIPS because it gave a scientific and economic excuse to do what I knew was the right thing,” she says. Morse expects results as the plants’ interconnected deep roots intercept sediment and nutrients. “I’m very excited about improving the microbial community in the soil and providing habitat for wildlife—mammals, insects and birds,” she says. “I hope the STRIPS project is enormously successful throughout the Midwest, prairie strips will become just as ubiquitous as terraces and waterways. They could be. They are less expensive and they’re more effective.”
The STRIPS concept started in 2004, moving to experimental trials in 2007. Ongoing team research at Iowa State University studies bird activity on two sites, monitors water quality and nutrients, and works with farmers to add new strips. ISU’s Tim Youngquist meets with farmers wanting to improve water quality and reduce erosion, but who don’t have much experience with prairie. Youngquist suggests seed types, seeding methods and times.
“For about $200 per acre, they can plant about 30 species, not trying to duplicate the natural system, but trying to mimic it,” he says. “This is something that helped form the soil. By putting plant species here that were here, they can help soil stay in place, help nutrients stay in place and get greater diversity of species—insects, pollinators and birds.”
Cost-share programs can fund portions of the project and may provide some ongoing income. Currently, there are 23 STRIPS projects throughout the state, including 17 on private land.