Nitrate leaching occurs more easily in Central Wisconsin because of coarse-textured soils and the types of crops commonly grown in Central Wisconsin which generally receive large amounts of nitrogen. Soil nitrate can easily be lost to groundwater particularly after heavy rainfalls.
Nitrate loads to groundwater have increased statewide, with studies estimating that over 10% of private wells in Wisconsin exceed the health standard of 10 mg/L. Researchers are looking at cover crops as part of a solution.
The fate of N is highly affected by on-farm factors such as cropping system, management practices, soil type and hydrology, as well as external factors such as weather conditions. There are many pathways for N loss from a cropping system including:
