Perennial prairie strips offer a new conservation tool

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PRAIRIE CITY, Iowa -- Perennial prairie strips can help improve ecosystem health on Midwest farms without compromising the benefits of agriculture, according to a multi-year project led by researchers at Iowa State University. The project began in 2007 with funding from the Leopold Center for Sustainable Agriculture’s Ecology Initiative and quickly gained momentum: Today, multiple funders provide support, and outreach partners like the Land Stewardship Project help disseminate the research.  

In a June 21 meeting, stakeholders discussed how to move the STRIPs project from science into practice.  Historically, prairies dominated Iowa’s landscape, creating the rich soils needed for productive agriculture. Now less than 0.1 percent of Iowa’s prairies remain. By restoring some of those deep-reaching perennial roots to row-cropped fields, farmers and landowners can reduce erosion and nutrient loss, keep waterways free of agricultural runoff and improve biodiversity.

 “We can strategically place perennial vegetation to provide disproportionate conservation benefits,” said Matt Liebman, team member and agronomy professor at Iowa State University. “A small change gives a large effect.”

In July 2007, guided by team leaders Matt Helmers, associate professor in ISU’s Department of Agricultural and Biosystems Engineering, and Heidi Asbjornsen, now an associate professor at the University of New Hampshire, researchers established a variety of treatments on 14 watersheds at the Neal Smith National Wildlife Refuge. Treatments ranged from conventional agriculture to reconstructed prairie to mixed systems with strategically placed perennial strips covering 10 or 20 percent of the watershed. Flumes at the toe of each watershed collect runoff for sampling.

Recent wet years have given the researchers opportunities to see prairie strips at work during high rainfall events. The long, upright stems of prairie plantings help resist water movement and trap sediment. In watersheds with 10-20 percent prairie strips in no-till cropland, sediment loss was reduced by more than 90 percent. Nitrate and phosphorus movement also decreased.

Reduced erosion and runoff aren’t the only benefits that prairie strips offer.  “With 10 percent of the watershed in prairie strips, you get these enormous increases in biological diversity,” Liebman said. Researchers track the abundance of plant, bird and insect species in each experimental watershed. In 2010, watersheds with prairie buffers contained an average of 61 plant species, compared to just 19 in cropland. Increased biodiversity provides useful services to farmers: Native birds and insects help control pests, pollinators visit both prairie and crop flowers, and wildlife offers opportunities for recreation.  

As a new conservation tool, perennial prairie strips offer a long-term investment in the health and resilience of farmland. However, current crop prices dissuade many farmers from taking land out of production. Stakeholders agreed that financial incentives and technical support are required. One possibility is that farmers can use modern agricultural technologies for “precision conservation,” identifying less productive areas of their farms to target for prairie strips.

Stakeholders also noted the need for one-on-one interactions with farmers, perhaps in the form of demonstration projects around the Midwest. For example, research and demonstration data can reassure farmers that weeds will not increase in cropland adjacent to prairie strips. One of the goals of the project is to bring together diverse groups of people—farmers, conservationists, policymakers and scientists—with a common understanding that agriculture and environmental stewardship can exist side-by-side.

The STRIPs team plans to continue their research at Neal Smith, including work on the socioeconomic aspects of implementing perennial prairie strips. The project is made possible by the cooperation of the Neal Smith National Wildlife Refuge and the U.S. Fish and Wildlife Service, with support from the Leopold Center, Iowa Department of Agriculture and Land Stewardship, USDA National Institute for Food and Agriculture, U.S. Forest Service, ISU College of Agriculture and Life Sciences and USDA North Central Region SARE program.

For more information, visit the STRIPs website at www.nrem.iastate.edu/research/STRIPs. View a slideshow of the stakeholder meeting at the Leopold Center website, or listen to a podcast at the Land Stewardship Project website.

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The Leopold Center was established by the 1987 Iowa Groundwater Protection Act as a research and education center at Iowa State University to develop sustainable agricultural practices that are both profitable and conserve natural resources. Iowa State does not discriminate on the basis of race, color, age, religion, national origin, sexual orientation, sex, marital status, disability, or status as a U.S. Vietnam Era Veteran. Any persons having inquiries concerning this may contact the Director of Affirmative Action, 3210 Beardshear Hall, (515) 294-7612.

This page was found at http://www.leopold.iastate.edu/news/06-29-2011/perennial-prairie-strips-offer-new-conservation-tool on 01/21/2013