Wisconsin Discovery Farms’ most recent projects focus on in-field nitrate leaching. Nitrate is one form of nitrogen that is naturally present in soil and water. However, in high concentrations, nitrate poses risks for human health. Nitrate is the most widespread contaminant in Wisconsin groundwater and can easily move through soil to groundwater. In agricultural fields, nitrate is an important form of nitrogen for crop production. Nitrate leaching, the movement of nitrate out of the crop rooting zone towards groundwater, is becoming a concern, especially in areas with coarse, sandy textured soils where water moves through the soil more rapidly than fine textured soils.
We began our first nitrogen leaching monitoring study in fall 2021 to better understand the timing and magnitude of nitrogen leaching in agricultural fields. We added two more monitoring sites in 2023. Each of these sites are row crop fields with grain or forage rotations. They are set up with a control and treatment design. To start, the entire field at each site will be managed the same. Then, after a few years of monitoring, a “treatment” will be added to half the field to see how it affects the timing and amount of nitrate that is leaching. The general treatment plan is to explore different aspects of manure or nitrogen fertilizer management in collaboration with our participating farmers. These projects are still in progress, so stay tuned to learn more about the results in the coming years.
