ST. PAUL — The Minnesota Department of Agriculture reminded farmers and landowners that beginning Sept. 1, the application of nitrogen fertilizer in the fall and on frozen soil will be restricted in areas vulnerable to groundwater contamination.

Restrictions will also apply to Drinking Water Supply Management Areas with elevated nitrate levels. Vulnerable groundwater areas include coarse textured soils, karst geology and shallow bedrock.

According to the department, 12-13% of Minnesota’s cropland is vulnerable to groundwater contamination. A map showing vulnerable groundwater areas as well as a list of exceptions to the restrictions are available by visiting

The MDA is also scheduled to host a webinar from 10 a.m. to 11 a.m. Wednesday, Aug. 12, to answer questions on the subject. Webinar details, a video detailing fall restrictions and links for additional information are available by visiting