The Minnesota Department of Agriculture has issued updated maps that will help farmers across the state comply with the Groundwater Protection Rule.
The Groundwater Protection Rule will reduce the risk of nitrate from fertilizer impacting groundwater in areas of the state where soils are prone to leaching and where drinking water supplies are threatened.
The rule will restrict fall application of nitrogen fertilizer in areas vulnerable to contamination and it outlines steps to reduce the severity of contamination in areas where nitrate is already elevated in public water supply wells.
The application of nitrogen fertilizer in the fall or on frozen soils will be restricted to quarter-sections of land where 50% or more of the quarter-section is in an area with vulnerable groundwater and in Drinking Water Supply Management Areas that have nitrate-nitrogen concentrations at or in excess of 5.4 milligrams per Liter nitrate-nitrogen.
An area with vulnerable groundwater is an area where nitrate can move easily through soil and into groundwater, contaminating drinking water sources. Some portions of the DWSMAs have low and very low vulnerability, those areas are not subject to the fall restriction.
MDACHECK THE MAP: Go online and view a map of Minnesota to see if your land is impacted by the state’s Groundwater Protection Rule.
Vulnerable areas for Part 1 of the rule are defined as:
- coarse textured soils based on USDA NRCS soils maps
- shallow bedrock based on USDA NRCS soils maps
- karst geology based on Minnesota Department of Natural Resources map
Restriction of fall fertilizer applications will begin in vulnerable groundwater areas in September 2020.
To determine if restrictions apply to your land, view the maps on the MDA website.