Minnesota Pollution Control Agency

Contact: Forrest Peterson, (320) 214-3789 Note to editors: A photo suitable for use with this news release is available in the News Media Center at hhref="/newscenter/index.html Marshall, Minn. -- With the summer dry season upon us, many farmers pray for enough rain to ensure a good harvest in the fall. Technology -- improved crop genetics, tillage practices and fertilizers -- has helped improve crop yields tremendously. But adequate rainfall still depends on the weather, and so far, technology can't control that. When rain does fall, recent developments in water management can help control what happens to it on farm fields. Farmers are becoming more aware of "conservation drainage," which can benefit both agriculture and the environment. During dry summer months, it can help retain a reservoir of groundwater for thirsty crops. Tony Thompson raises corn and soybeans on 2,000 acres in the northeast corner of Jackson County. The heavy clay soil is poorly drained, typical of about half of the farmland in Minnesota. Like many farms over the past century, vast networks of ditches and subsurface drain tile have transformed the land from prairie and water-filled potholes to highly-productive cropland. The downside is that uncontrolled drainage can contribute to water pollution from sediment and fertilizers in stormwater runoff. "Adding tile in some cases was a distinctly un-neighborly thing to do," Tony says. "Now I try to do all I can to improve my own land while imposing the least harm downstream. For example, I try to hold water on my land for three days. It's a complicated process." Conservation drainage is the use of drainage practices designed to provide the benefits of drainage while minimizing negative impacts on the environment, according to the Minnesota Department of Agriculture (MDA). MDA Assistant Commissioner Robin Kinney says it's important for landowners to have some solutions to help them meet drainage challenges: "We need to continue to provide producers and landowners with real-life, working demonstrations that incorporate improved designs and management practices for their land." Expanding the practices can play a role in improving water quality in rivers, lakes and streams. Specific projects of the Minnesota Pollution Control Agency and local groups are or will be under way to reduce pollution in hundreds of water bodies in Minnesota. "Subsurface drainage puts a lot of sediment-free water into ditches and streams and this can influence channel bed and bank erosion," says Dr. Joe Magner, MPCA hydrology expert and University of Minnesota (U of M) adjunct professor. "The volume and velocity of water movement can cut into channels and cause them to erode and become unstable, which can lead to water-quality problems," Magner says. "Hydrology management is only one factor; we also need to get pollutant treatment out there in some fashion or another." "Current water-quality impairments in the Minnesota River and many of its tributaries, such as turbidity, excess nutrients, and fecal coliform bacteria, point to an immediate and continuing need for practices and sustainable management systems that improve water quality while optimizing agricultural production and farm profitability," says Jeff Strock, U of M soil scientist and drainage researcher. "Drainage water management like the system at Tony's is not a silver bullet that alone will improve water quality. We must implement integrated management practices across the landscape and think of them as silver BBs." Recently, Thompson received a grant from the Department of Agriculture to install equipment that controls the flow of water coming from a network of subsurface drain tile in a 160-acre field. After the crop is planted, gates in the control structures can be raised to hold back water in the tile system. This makes more water available to the crops instead of draining off and carrying away pollutants. "The project is good for the farmer and good for the environment," Thompson says. "Controlled drainage is part of a new approach to water management. I'm willing to make the investment in technology, but financial incentives are needed." Over the years, Thompson has used numerous conservation practices on his farm, including ridge-tilling, installing grass filter strips, and closing open tile intakes. The goal is to keep farmland productive while reducing soil erosion and runoff of fertilizer and chemicals. Scientists believe that fertilizers - nitrogen and phosphorus - in runoff from Upper Midwest farm fields contributes to a large area in the Gulf of Mexico where aquatic life suffers from low dissolved oxygen. The nutrients fuel algal growth, and bacteria use oxygen in consuming algae. A 20 percent reduction in drainage from fields could bring a corresponding reduction in nitrogen. Farmers are well aware of the issues and are willing to work on solutions, says Warren Formo, director of the recently organized Minnesota Agricultural Water Resources Coalition. "The agriculture community is open to the conservation drainage idea. We're seeing a lot of older systems being replaced with pattern tile having fewer open inlets. We need to study drainage and do it better." Jamie Duininck, of Prinsco, a drain tile manufacturer headquartered in Willmar, is vice president of the Agricultural Drainage Management Coalition. "Drainage is misunderstood," Duininck says. "A 40-acre field may have 40,000 feet of tile in a close pattern, which can actually be like a sponge." The coalition received a federal grant for research projects in five states on drainage water management. About a dozen projects are in Minnesota, including the controlled outlet structure at the Thompson farm. "When I saw the technology for controlled drainage really coming along, I talked with Gary Sands," Thompson said. After attending a tiling workshop last year, he decided to go ahead with the project. Sands, a U of M Extension Service engineer and one of the leading researchers on drainage, reports that in general, artificial drainage may increase the amount of water leaving a field by 10 to 15 percent. Continued research shows promise that conservation drainage techniques such as controlled outlets may accommodate crop production needs while reducing water pollution downstream. MPCA and university researchers also are studying better designs for drainage ditches. Web sites with information on agricultural drainage: Agricultural Drainage Management Coalition: http://www.admcoalition.com
Minnesota Department of Agriculture: http://www.mda.state.mn.us/protecting/conservation/drainage-opps.html
Natural Resources Conservation Service: http://www.swi.nrcs.usda.gov/products/W2Q/water_mgt/Drainage/Drainage.html
MPCA Nonpoint Source Management Program Plan: hhref="/water/nonpoint/mplan.html
University of Minnesota Extension Service: http://d-outlet.coafes.umn.edu