Title: Water quality performance of prairie strips
Location: Four Locations throughout Iowa
Time Period: 2014-present
Research Team: Matt Helmers, Chris Witte, Lisa Schulte Moore, and Matt Liebman
Project Description: The STRIPS project (Science based Trials of Rowcrops Integrated with Prairie Strips) conducted at Neal Smith National Wildlife Refuge (NWR) near Prairie City, Iowa (http://prairiestrips.org) has documented water quality benefits as well as increased biodiversity across several taxa, achieved by integrating tallgrass prairie vegetation (prairie strips) into row-cropped watersheds. The experimental watersheds at Neal Smith NWR incorporating as little as 10% field acreage in prairie strips within no-till corn/soybean row crops reduced losses of sediment by 95%, nitrogen in runoff by 84%, phosphorus in runoff by 89%, and water runoff by 60% compared to watersheds without prairie strips. Over the past few years the ISU team has been working to install prairie strips throughout Iowa. The ISU team received funding from IDALS, USDA-FSA, USDA-NIFA, and the Iowa State University College of Agriculture and Life Sciences to establish monitoring infrastructure at six of these prairie strips sites. The six sites with monitoring infrastructure are the paired comparison sites.
Our preliminary surface runoff results indicate that surface runoff volume is usually less in the drainages with prairie strips, but not by much. One notable exception is the McNay site and there are at least two contributing factors to why measured runoff is greater in the treatment as opposed to the control field. Firstly, we have had some difficulty getting all of the runoff to flow through the flume for measurement on the control field, as some runoff is failing to enter the grassed waterway where the flume is installed. We hope to fix this problem before monitoring begins in 2020. Secondly, there is a side slope seep in the treatment field that we believe contributes to greater runoff volume as well as reduces infiltration of rain into the soil. In general, the drainage areas with prairie strips are losing less nitrogen, phosphorus, and sediment. However the results are not as dramatic as the work at Neal Smith likely due to the paired field comparison sites all having grassed water ways.
Funders: Iowa Department of Agriculture and Land Stewardship, Iowa Nutrient Research Center, USDA Farm Services Agency, Foundation for Food and Agriculture Research, US. Forest Service Northern Research State, and USDA-NIFA
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