Farmers, Researchers Report Nitrate Reductions in Rice Creek

Farmer Tim Little talks about the benefits of cover crops to his farming operations near Rice Creek on March 21, 2023 in Faribault. Credit: Theresa DeMars, Rice Soil and Water Conservation District

In a small watershed near Dundas in southeastern Minnesota, farmers, conservation professionals, researchers, and a local nonprofit, Clean River Partners, are working together to reduce nitrate in Rice Creek, the only self-sustaining brook trout stream in Rice County. Across Minnesota, most stream pollutants like phosphorus and sediment are decreasing or staying the same. But nitrate pollution has been harder to affect and is stubbornly on the rise in rivers, lakes, and drinking water wells.

On Tuesday, March 21, people who are part of “Farmers Protecting Bridgewater Streams'' met in Faribault to discuss the status of the five year project to prevent nitrate from entering Rice Creek. Since 2018, farmers have planted cover crops on about 30% of the tillable land that drains into Rice Creek. Cover crops (plants like cereal rye, winter wheat, oats, radish, and clovers) capture and hold soil and nutrients like nitrate fertilizer in the fields, rather than allowing that nitrate to enter streams through tile drainage or wash into waterways with rain.

At the meeting, area farmers Mark Legvold and Tim Little discussed how using conservation practices like no-till and strip-till planting techniques and planting cover crops have made their fields more resilient to both heavy rainfall and to recent extreme dry periods. They also pointed out that their farms are more profitable now that they use these conservation practices. Legvold shared, “Using cover crops and no-till is a continuous process of adjustment that we have to approach with a scientific mindset. While some farmers start with a clean, blank slate, we are constantly building on the work from the previous years, making adjustments and experimenting with methods. The difference is the savings in fuel and machinery wear and tear, less time in the field tilling and picking rocks, and increased productivity with fewer inputs."

St. Olaf College chemistry professor Paul Jackson and Minnesota Pollution Control Agency watershed specialist Kristen Dieterman shared data from two separate studies that showed a decrease in nitrate in both the field tile drainage lines and the creek itself. Dieterman framed the importance of this, “Nitrate is an essential building block of life, however, high amounts can be detrimental to fish, bugs, and humans. Nitrate concentrations in Rice Creek have placed it on the federal Impaired Waters List. Samples collected in the creek since 2019, though, show nitrate levels are decreasing. The MPCA will keep collecting data with the hope that this trend continues.”

All members of the project team were encouraged that the farmers using the conservation practices have continued to be profitable while also benefiting the land and water in and around Rice Creek. In a panel discussion after the presentations, St. Olaf College biology professor Kathy Shea asked how we sustain the success of this grant-funded project. Clean River Partners executive director, Jennifer Tonko, responded, “This is a collaborative effort. Clean River Partners, in our role as a nonprofit, is able to pull together people with many different roles who care about the quality of Rice Creek. As long as we’re able to continue bringing together these partners, the work will continue.”

Article written by Jennifer Tonko, Clean River Partners Executive Director