While drainage can have numerous benefits to farmers, it can also have unintended negative impacts on the environment. Most notably, nitrogen and phosphorus can escape fields through drain tile and contribute to water quality issues—especially in intensively drained agricultural regions like the western Lake Erie watershed. Researchers across the Midwest are promoting water retention and reuse systems that allow farmers to drain their lands with minimal impact to the environment.
The Ohio State University’s Lima Campus is surrounded by ~150 acres of farmland that drain to Lake Erie’s headwaters. Here, OSU researchers are testing multiple new and direct means of reducing nutrient losses by transforming how drainage tile is managed. Using funding from the Great Lakes Restoration Initiative, EPA partnered with Ohio EPA, Dr. Vinayak Shedekar, Assistant Professor at OSU, and the Allen County Soil and Water Conservation District to launch the “Drainage Water Recycling” demonstration project in 2022. A saturated buffer system was installed to collect and treat 12 acres of cropland drainage water by diverting it through a vegetated buffer before discharging. Saturated buffers significantly reduce the amount of water discharged and at much lower nutrient concentrations, require little maintenance and do not negatively affect crop yields.
The researchers also installed a wetland, floodplain and a water retention pond on approximately 5 acres of cropland. These features together capture and treat runoff from approximately 40 acres of row crops. Runoff captured in the storage pond can be used for irrigation during dry periods, applying the captured water and nutrients back onto fields when crops are most in need of moisture and nutrients. An automated water control structure makes it easy to respond and prepare for changes in rainfall. These benefits create a positive tradeoff for taking land out of production.
These projects were constructed during 2022-2024 and are being actively monitored. So far, the data shows potential of this system to significantly reduce sediment, nitrogen, and phosphorus exports by eliminating up to 100% of the runoff during extreme rain events. At the same time, the cropped fields are producing higher yields. According to OSU, farmers in Northwest Ohio can expect a 19% higher corn yield and a 12% higher soy yield in dry years with the help of drainage water recycling and irrigation.
To learn more about the project, visit the project page on Ohio State University’s website.
To learn more about additional conservation drainage projects, visit the Transforming Drainage website.