Goal: develop a way for farmers to succeed while protecting drinking water

Gloria Hafemeister
The recent two Discovery Farms virtual conferences highlighted changes regarding manure and nitrogen applications in fall and winter in many areas of Wisconsin and Minnesota.

WISCONSIN DELLS – While Wisconsin continues to look at ways to regulate nitrogen applications in areas that are vulnerable to groundwater contamination, Minnesota has developed strategies for nitrogen management. 

Some experts who worked in the development of that program shared their experiences with farmers, crop consultants and others attending the recent Discovery Farms Program in Wisconsin Dells.

Warren Formo, Minnesota Agricultural Water Resource Center executive director, moderated a panel of industry professionals at the event. Panelists shared how the Minnesota program has worked to address drinking water issues in sensitive areas of the state.

Minnesota’s rule, based on the Minnesota Nitrogen Fertilizer Management Plan that originated in 1990, applies to two categories of water resources—vulnerable groundwater areas and Drinking Water Supply Management Areas (DWSMA).

The rule restricts fall application of nitrogen in areas of the state where groundwater is vulnerable to contamination, and requires best management practices and alternative management practices in DWSMAs where nitrogen concentrations are above levels specified in the rule. 

The rule limits nitrogen fertilizer application in vulnerable groundwater areas – defined as such based on soil type (coarse textured soils) or geological features (shallow bedrock or karst geology) – or where a municipal public water supply well is already threatened with nitrate-nitrogen contamination.

“Discussions did start with farmers and non-farmers disagreeing but as the discussions went on each group came closer together,” Formo said.

He noted that the goal from the start was to develop a way for farmers to succeed while still addressing the need to protect drinking water.

One of those areas of Minnesota greatly affected is in the Hastings area where Jill Trescott serves as the senior water advisor in an area of the state that has a lot of population but also has many farms.

Following the initial well water testing in the area Trescott said, “We were disappointed to find out that the results were worse than what we expected.”

The high nitrate concentration can be blamed on the area’s intensive farming with fertilizers, sandy soil and old wells that are susceptible to contamination,” she said.

While nitrogen is needed and used on cropland to support agriculture, the issue of nitrate contamination of groundwater and associated health impacts is a growing concern in Wisconsin and other states.

Trescott was very involved in establishing the nitrogen use plan and said the effort was accomplished in a cooperative way. 

"We were committed to improving water quality but also protecting the valuable farm businesses in our area," she said. “We’re in the Twin City metropolitan area but half of our county is in farming. Growth in the area has seemed to stabilize and we expect those farms will remain.”

Trescott says that the area is comprised mostly of crop farming and almost no livestock situations. The area is also the second highest user of water for irrigation in Minnesota.

One of the farmers that uses irrigation was also on the Discovery Farms program panel.  Jake Wildman, president of the state’s irrigation organization, says that this year the ability to irrigate was especially important as most of the crops would have been lost without irrigating.

Wildman shared the use of Best Management Practices (BMP) that not only protect groundwater supplies by decreasing the amount of fertilizer used but they also help farmers by providing a guide for how much fertilizer to use without using more than needed for a good crop.

The purpose of the BMPs is to protect water quality while at the same time maintaining farm profitability, he said, adding that they must also be practical to implement.  Those practices could include timing, rate, placement and source of fertilizer application and other practices that increase fertilizer use efficiency and decrease potential loss to the environment.

Prescott says that while the BMP’s address the economics of using too much fertilizer, they do not necessarily serve to protect leaching into the groundwater.

“I believe there will be some new products coming onto the market that would allow corn to grow without as much nitrogen fertilizer," WIldman said. "I also believe that when farmers use the best management practices established by the university that not only save money but leaching should also go down.”

Wagner points out that the BMP’s were updated last in 2008 and will be updated soon according to the later research which not only looks at economics but also at water quality.

“We know in some of the more critical areas BMP’s may not be enough," Wagner said. "We need to do more.”

In Wisconsin, most of the issues associated with groundwater are related to livestock and manure management. Formo points out that in Minnesota, livestock and manure issues are regulated by a different agency that does require that nitrogen credits be considered when applying manure.

Asked about how human waste fits into the issue, Formo replied that new regulations also look at septic systems.