Groundwater Protection Rule to restrict fall fertilizer application in identified, vulnerable areas

Groundwater Protection Rule to restrict fall fertilizer application in identified, vulnerable areas

WASECA, Minn. (KEYC) — A new state rule taking effect this year aims to keep nitrate pollution out of Minnesota’s groundwater and protect the state’s drinking water.

It took effect last month, but it won’t play a role in day-to-day operations until September. The Groundwater Protection Rule contains two parts.

“Primary emphasis is to protect drinking water that our residents are drinking, so that is the main emphasis,” said Jeff Vetsch, a researcher at the University of Minnesota Southern Research and Outreach Center.

Part one of the rule focuses on restrictions in nitrogen fertilizer application. That will affect operations that farm in areas identified as having vulnerable groundwater or areas around public wells.

“Throughout the central sands of Minnesota, the Twin Cities area, and up along the I-94 corridor and just south of the Twin Cities, those are the areas that are primarily affected, but also, there are spots in Nicollet and Brown County, just little patches somewhere right around St. Peter, and then some along the Minnesota River Valley,” said Vetsch.

Areas identified with vulnerable groundwater tend to have coarse-textured soils and shallow bedrock and are subject to the restrictions.

“You can apply up to 40 pounds of nitrogen in these areas if they’re fall ammoniated fertilizers, like ammonium phosphates and sulfates, that farmers typically apply in the fall and also these exclusions are for perennial crops or crops that are established in the fall,” Vetsch added.

That includes things such as forages and pastures, but Vetsch says 40 pounds is the maximum amount that can be applied in the fall in restricted areas.

Groundwater Protection Rule

The Groundwater Protection rule minimizes potential sources of nitrate pollution to the state's groundwater and protects our drinking water. The rule restricts fall application of nitrogen fertilizer in areas vulnerable to contamination, and it outlines steps to reduce the severity of the problem in areas where nitrate in public water supply wells is already elevated.

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