Prairie strips are a farmland conservation practice that deliver enormous soil, water and nutrient benefits while increasing wildlife habitat. Prairie strips:
- Were developed as a result of scientific experiments,
- Help conserve farmland by strategically incorporating native prairie plants into crop fields; and
- Are compatible with existing federal and state cost-share programs so farmers who implement them can recoup some of their costs, estimated at between $28 and $39 per protected acre per year.
Results from more than eight years of trials showed that by converting 10 percent of a crop field to prairie strips could result in reduction of 95 percent of the sediment, 90 percent of the phosphorus and 84 percent of the nitrogen from overland flow of surface water. The experimental sites were not tile drained and all systems used no-till.
Not Your Typical Contour Buffer Strip
Contour buffers are typically planted with fixed widths. In contrast, we vary the width of the prairie strips based on the amount of water they intercept, with the goal of treating all of the runoff leaving the crop field. Where more water is flowing down-slope, prairie strips should be wider, and where less water is flowing down-slope, the strips can be narrower. Also, the types of plants used for conservation buffers and filter strips can affect how they function. Cool season exotic grasses such as smooth brome and Kentucky bluegrass are widely used to provide ground cover in agricultural areas of the U.S. Corn Belt, but are relatively weak-stemmed and prone to laying flat under heavy rain. They are useful for grassed waterways that are intended to convey water while preventing erosion. In contrast, native tall-grass prairie communities are typically dominated by stiff-stemmed warm season grasses such as Indiangrass, big bluestem, little bluestem, and a wide range of erect forb (i.e., wildflowers) species that are less prone to collapse under heavy rain. These native plants are more effective in providing resistance to water flow and sediment movement.
How Are Prairie Strips Implemented?
Prairie can be planted several times throughout the year. It is preferable to seed in either the fall after harvest, or the spring, before or after planting (but before June 30 in Iowa). Midsummer is generally not a good time to plant. Prairies include two basic types of plants, forbs (i.e. wildflowers) and grasses. Forbs benefit from the cold wet stratification an Iowa winter provides, and like a fall seeding. Prairie grasses should be seeded in greater volume for a fall seeding as their germination rates suffer from predation and exposure. Dormant, or winter seedings also can be successful. There are numerous native seed dealers and technical service providers throughout Iowa and the Midwest. The Plant Iowa Native website has a comprehensive list and contact information for seed sales and technical service providers. This Iowa State University decision support tool can help with estimating costs.
You should be aware that multiple years will be required, three at minimum, for your prairie strips to start really looking like a prairie.
- During the first year, mowing is required. The strips will look like a short, vegetated buffer. It will not look like a prairie. Native species put most of their first-year energy in their roots and will not produce significant above-ground biomass.
- During the second year, early species (i.e., Canada wild rye, partridge pea, and black-eyed Susan) will be recognizable and may bloom. Unless there is considerable weed pressure, mowing is not necessary. Spot spraying can be used in year two if there are weedy areas.
- By the third year, most prairie restorations will begin to resemble a diverse native tallgrass plant community.
- Thereafter, maintenance will consist of spot application of herbicide as needed and baling or prescribed burning of the strips if desired. If prairie strips become dominated by weeds or invasive species, maintenance mowing and application of herbicide can be used to control them. Weeds and invasive species can be held in check by planting a diverse mix of native species in the initial planting and mowing the strips in the first year.
Interested in learning more?
Check out our FAQ page. You can also find webinars by the STRIPS team and farmer collaborators by searching this website (find search box just below the banner on this page). You can listen to testimonials from farmer collaborators in this movie. Contact the STRIPS team at firstname.lastname@example.org with questions and technical assistance with field layout.