The Minnesota Department of Agriculture (MDA) has distributed a news release to remind farmers that the application of nitrogen fertilizer in the fall and on frozen soil will be restricted in areas vulnerable to groundwater contamination and in Drinking Water Supply Management Areas (DWSMAs) with elevated nitrate levels beginning on September 1, 2020. The nitrogen fertilizer restrictions are included in the Minnesota Groundwater Protection Rule which became effective on June 24, 2019, and are based on the recommendations
included in the Minnesota Nitrogen Fertilizer Management Plan (NFMP; March 2015, Addended July 2019). The nitrogen fertilizer restrictions are intended to protect groundwater, including groundwater used for drinking water
that may be, or has already been, impacted by the 12-13% of Minnesota’s cropland that is vulnerable to groundwater contamination by nitrates from nitrogen fertilizers.
The Groundwater Protection Rule has two parts: Part 1 which restricts the application of nitrogen fertilizer in the fall and on frozen soils in agricultural areas that are vulnerable to groundwater contamination and in protected areas around public wells – Drinking Water Supply Management Areas (DWSMAs) – that have high nitrate levels (nitrate-nitrogen concentrations at or in excess of 5.4 mg/liter), and Part 2 which focuses on public water supply wells with elevated nitrate levels and the protected areas around these wells (the DWSMAs) and
includes a combination of voluntary and regulatory efforts designed to mitigate nitrate levels before they exceed the drinking water standard (10 milligrams of nitrate-nitrogen/liter).
Vulnerable groundwater areas include areas where nitrate can move easily through the soil and into groundwater and contaminate drinking water resources including areas with coarse textured soils, karst geology, and shallow bedrock. Karst
geology is dominated by underground fissures and voids that makes them very porous and allows water to move through them rapidly and where contaminants can reach groundwater resources quickly; in Minnesota, karst geology is primarily found in
Affected agricultural lands can be located on an interactive, online map available on the MDA website that shows the vulnerable groundwater areas and DWSMAs with a resolution down to the individual farm level (see the link below).
Excluding Drinking Water Supply Management Areas (DWSMAs) with nitrate-nitrogen levels greater than or equal to 5.4 mg/liter, several counties that have a low potential for nitrate leaching based on climate (precipitation and evapotranspiration rates), have a short planting season, or have a limited amount of agricultural land (less than 3%) are excluded from the fall nitrogen fertilizer restrictions and there are also a number of state-wide exceptions to the Minnesota Groundwater Protection Rule. These
exclusions and exceptions are outlined in the rule and on the MDA website (see the links below).
The MDA has developed a recorded presentation (YouTube video) that explains the purpose of the Groundwater Protection Rule, where the nitrogen fertilizer restrictions apply, and the exceptions to the rule. This
presentation may be accessed through the MDA website at https://www.mda.state.mn.us/groundwater-protection-rule-webinar
or directly at https://www.youtube.com/watch?v=FWKYOO0wvfs&feature=youtu.be
. In addition, the MDA will be hosting a webinar on Wednesday, August 12 from 10:00 until 11:00 a.m. to answer questions about the Minnesota Groundwater Protection Rule and the associated nitrogen fertilizer
The MDA news release about the nitrogen fertilizer restrictions is available on the MDA website at https://www.mda.state.mn.us/nitrogen-fertilizer-restrictions-begin-september-1.
Additional links to information about the Groundwater Protection Rule:
Information about the Minnesota Groundwater Protection Rule (Parts 1 & 2) and the text of the Minnesota Groundwater Protection Rule (Minnesota Rules Chapter 1573 – Department of Agriculture Groundwater Protection) are available at
https://www.mda.state.mn.us/nfr and https://www.mda.state.mn.us/sites/default/files/2019-07/finalgprrevisorsoffice.pdf
The Minnesota Nitrogen Fertilizer Management Plan (NFMP) is available at https://www.mda.state.mn.us/sites/default/files/2019-08/nfmp2015addendedada_0.pdf
A link to the interactive, online Vulnerable Groundwater Area Map is available on the Minnesota Department of Agriculture website at https://www.mda.state.mn.us/chemicals/fertilizers/nutrient-mgmt/nitrogenplan/mitigation/wrpr/wrprpart1/vulnerableareamap
or directly at https://mnag.maps.arcgis.com/apps/webappviewer/index.html?id=47a342afe6654640b935c8e76023da92
Factsheets about Part 1 of the Minnesota Groundwater Protection Rule (including exclusions and exceptions to the nitrogen fertilizer application restrictions), Part 2 of the Groundwater Protection Rule, and answers to predetermined questions about
the Groundwater Protection Rule are available at
Information about Nitrogen Fertilizer Best Management Practices (BMPs) for Agricultural Lands is available through the Minnesota Department of Agriculture website at
Additional information about the Minnesota Groundwater Protection Rule and the nitrogen fertilizer restrictions is included in a recorded presentation prepared by the MDA and will be presented along with an opportunity to have questions answered
through a live MDA webinar scheduled for Wednesday, August 12, 2020, from 10:00 until 11:00 a.m. via WebEx; information about these resources is available at
Information about Alternative Management Tools (AMTs) that go beyond traditional nitrogen fertilizer BMPs is available on the Minnesota Department of Agriculture website at
If you have questions or comments regarding this MNLA Regulatory Update or the nitrogen fertilizer restrictions under the Minnesota Groundwater Protection Rule, contact Jim Calkins, MNLA Regulatory Affairs Manager, at
firstname.lastname@example.org or 952-935-0682.
Figure 1. An example of a fertilizer analysis, specifically a fertilizer that contains 15% nitrogen (8.4% ammoniacal nitrogen and 6.6% nitrate nitrogen) by weight; nitrogen fertilizer restrictions designed to protect groundwater and drinking water resources from contamination by nitrates by restricting the application of nitrogen fertilizers on agricultural lands in the fall and on frozen ground are scheduled to become effective on September 1, 2020 (Photo Credit: James Calkins).