The Minnesota Department of Agriculture (MDA) is reminding farmers and landowners that beginning Sept. 1, 2020 the application of nitrogen fertilizer in the fall and on frozen soil will be restricted in areas vulnerable to groundwater contamination. This will also apply to Drinking Water Supply Management Areas (DWSMAs) with elevated nitrate levels. Vulnerable groundwater areas include coarse textured soils, karst geology and shallow bedrock. Approximately 12 to 13 percent of Minnesota’s cropland is vulnerable to groundwater contamination. A map showing the vulnerable groundwater areas as well as a list of exceptions to the restrictions are outlined on the Groundwater Protection Rule website.

Throughout the 2018 Legislative Session, the Minnesota Soybean Growers Association pushed back against the “Nitrogen Fertilizer Rule,” leading a judge to temporarily delay the rule’s implementation.

A short video on the fall restrictions and links for additional information are available on the MDA website.  The MDA will also hold a webinar on Aug. 12, 2020, from 10 to 11 a.m. to answer questions. The video and webinar details are available online.

The nitrogen fertilizer restrictions are part of the Groundwater Protection Rule, which minimizes potential fertilizer sources of nitrate pollution to the state’s groundwater and works with local farmers to prevent public water supply wells from exceeding the drinking water standard for nitrate contamination.