By Scout Nelson
The Minnesota Department of Agriculture (MDA) is reminding farmers and commercial applicators that fall nitrogen fertilizer applications are restricted in certain parts of the state beginning September 1. These rules are part of the Groundwater Protection Rule, designed to reduce nitrate contamination in vulnerable areas.
According to the MDA, fall nitrogen fertilizer use is prohibited in areas with coarse-textured soils, shallow soils to bedrock, or karst geology. These conditions increase the risk of nitrate-nitrogen loss and potential groundwater contamination. Farmers are encouraged to use the MDA’s online map to check whether their fields are included in the restricted zones.
In regions of the state where fall applications are allowed, the MDA advises that fertilizer should only be applied when soil temperatures consistently reach 50 degrees Fahrenheit or cooler. Research shows that waiting until soils cool reduces nitrogen loss, improves water quality, and ensures that nitrogen is available for the following crop season.
The MDA also operates a Six-inch Soil Temperature Network with real-time readings at 70 locations across Minnesota. The tool allows users to view both current soil temperatures and historical data, helping farmers make informed decisions. The network is equally useful for those applying manure in the fall, as the University of Minnesota Extension recommends waiting until soil temperatures are below 50 degrees to reduce leaching losses.
For more information, farmers can visit the MDA website for both the vulnerable areas map and the soil temperature tracking tool. These resources are designed to support good nutrient management practices that balance crop productivity with environmental protection.
The MDA emphasizes that following these restrictions and recommendations not only protects Minnesota’s groundwater but also ensures more efficient use of nitrogen, supporting both the environment and agriculture.
Photo Credit:pexels-jan-kroon
Categories: Minnesota, Energy