Water & Drainage Ag producers know how water works—there’s either too much of it or not enough. They need a way to control water; to fine-tune water delivery on THEIR terms. It might be time to consider adding conservation drainage practices to your operation. Talk to NRCS today. See how well these techniques could work for you!
Conservation Drainage Practices:
Denitrifying Bioreactor
Drainage Water Management (DWM):
Place a Denitrifying Bioreactor near the end of a tile line, just before the drainage water leaves your farm. Though bioreactors can work on larger systems, about 100 acres of drainage is a practical limit for effective treatment. Using water control structures, you can send some or all the water from your drainage tile through a trench filled with wood chips. Denitrifying bacteria in those wood chips can remove any nitrates in the water. Flat ground or sloping, and whatever soil you might have–this practice works wherever you want it to.
DWM is the process of managing the timing and the amount of water discharged from agricultural drainage systems. DWM allows you to hold water in the root zone when crops need it and drain the field when there’s too much. This practice works best on relatively flat crop fields but can be made to work on more sloping ground if the tile laterals are laid across the slope instead of straight up and down. DWM systems can also retain water in fields that could be used for crop production later in the season. For more information, visit our DWM site.
Another treatment option for the end of a tile line is the Constructed Wetland–sometimes nicknamed “Nature’s Kidneys.” The wetland is sized to remove nitrates from tile water through plant uptake and denitrifying bacteria. The wetland can also remove phosphorus and provide wildlife habitat—added benefits! The wetland surface area should be at least 1% of the acres drained by the tile system.
The Saturated Buffer treats tile water by running some of the water to a lateral distribution pipe placed along the length of a ditch or streambank. Bacteria in the soil work to remove nitrates and the plants in the buffer take up nutrients as well. The saturated buffer works in places where the soil has plenty of organic matter, and where it’s possible to maintain a high water table.
Conservation Choices Practice Spotlight Series:
Denitrifying Bioreactor - An edge of field structure containing a carbon source, such as wood chips, installed to reduce the concentration of nitrate-nitrogen in subsurface agricultural drainage flow via enhanced denitrification.
Nutrient Management - Nutrient management means managing the amount (rate), source, placement (method of application), and timing of plant nutrients and soil amendments. These steps reduce the potential for nutrients to go unused and wash or infiltrate into water supplies. Nutrient sources include animal manure, sludge, and commercial fertilizers.
Cover Crops - Grasses, legumes, and/or broadleaf species planted for seasonal vegetative cover to control erosion, scavenge nutrients, and improve soil health.
Filter Strip - A strip of dense herbaceous vegetation such as grass, that filters runoff and removes contaminants before they reach water bodies or water sources. Filter strips are most effective when used in combination with other agronomic or structural conservation practices.
