Yellow Medicine SWCD Tile drainage is nearly a universally applicable investment made into cropland in our area. While the benefits of tile drainage are improved traffic-ability and increased crop yields from the removal of excess water, open inlets or intakes can convey not only corn stalks, rodents and other obstructions into your drainage system, but also can deliver sediment and phosphorus to stream systems which have a detrimental impact on water quality. Some intakes are needed to act as somewhat of a relief valve for tile flow or to act as an outlet for a conservation practice. Intakes that are necessary for operation should be utilizing a “riser” type inlet to meter water flow and prevent debris from entering the system. While many landowners and producers have seen the benefit of removing the open inlets that are malfunctioning, accidentally buried or not needed, many folks who may be even have thought about it have not. The SWCD has funding available to you that can be made available within a month of a request to assist in the cost of removing these intakes. Many type of intakes exist some utilize rock, geotextile, pipe or just perforated plastic tile. Not only does it block the path of sediment, debris and potential lost nutrients, but it slows the velocity of water making its way to ditches and streams which aids in the reduction of streambank erosion, a known source of sediment in the Minnesota River.
Tile systems are also known to deliver Nitrates into surface waters. One strategy that can be used to reduce nitrates in tile drainage water is drainage water management. With drainage water management, water level control structures are included as a part of the tile drainage system. These structures are used to manipulate water levels at different times during the year. The greatest nitrate removal benefits occur when water levels are maintained in the biologically active zone during the growing season where nitrates can be converted to nitrogen gas by denitrifying bacteria or taken up by a crop when most readily available. A properly managed system can also increase crop yields by conserving water in the soil profile for crops to utilize. Like the removal of open inlets, this practice retains water in the soil profile for a longer period of time.
When is drainage water management a good fit for a new or an existing tile drainage system? Generally, drainage water management is unfeasible on land slopes greater than about one percent. It may be possible to retrofit existing tile installations with water level control structures depending on how the tile layout fits with the field topography. Tile systems utilizing drainage water management do not require closer tile spacing, but tile layout should be aligned with the field’s contours as much as possible in order to provide the most complete coverage and consistent water levels across the field. State and Federal funds are available for assistance in planning and installing these type of systems. Retrofits can also be added in some situations to implement subsurface irrigation in feasible locations.
The mission of the Yellow Medicine Soil and Water Conservation District is to provide technical, financial, and educational support to its residents. Contact the Yellow Medicine Soil and Water Conservation District (SWCD) office in Clarkfield to find out more information about our programs, or call the office at (320) 669-4442 ext. 3. Our website also has a lot of information on all of our programs and services. Visit www.yellowmedicineswcd.org to learn more and stay up to date on all Yellow Medicine SWCD has to offer and what we are working on. You can also like us on Facebook.