ECOLUTION: The Science of Agriculture That Impacts Water and Soil Health

Ecolution reporting made possible by Seward Co-op, which has been a community-owned grocer since 1972: Together, we continue to cultivate a cooperative economy.

At a recent forum hosted by Active Voices and the Climate Action Team at First Unitarian Society of Minneapolis, the pervasive issue of agricultural impact on water quality was raised by the speaker, Steve Ring of the Sierra Club. During the Q&A, audience (and Changemakers Alliance) member Audrey Kingstrom noted that she grew up on a farm in west central Minnesota, which has since become an industrial hog farm. She said, “One of the things I’m constantly reminded of, having farmers in my family, is that they are responding to the markets. We are part of the markets — the food we eat and what we want to buy.”

She said that it was in the 1970s that the University of Minnesota encouraged industrial agriculture. “So this is a very deep and complicated problem,” she said. “Minnesota farmers just want to make a living. For many, large-scale farming is the road that they’ve seen as the best way to survive. That is the road my brother set on with the family farm. Are there ways that we who care about this issue can be impactful? And to support solutions that are more than ‘we need to regulate you,’ which is an antagonistic approach. There does need to be some regulation. But do you have thoughts about how to work on this from a very human perspective?

The Economics of Farming

In response, and as part of his talk, Ring said:

I agree entirely that the farming community is not the enemy. We’re all part of this. It is the choices that we make in the market — the meats that we eat, for example — as well as government. Those choices lead to ways the farming community has to make decisions.

There is some criticism that the Minnesota Department of Agriculture is asking farmers to address solutions on a voluntary basis, but in many ways, I think that’s the way to do it. If we can bring people along with training, with developing other crops, building more support for developing markets. It is one thing for Forever Green to develop Kernza, which is a perennial grain, but there also has to be a consumer market for it. We need to work with the farmers, we need to work with the markets, we need to work with General Mills or somebody to incorporate it into their products.

One of the reasons I think the Land Stewardship Project is so good is that they work in the farming community. I think that our university system and our state agriculture department needs to work on the economics. There’s some of that going on already — demonstrating how farmers can make a living by using slightly different methods. 

Farm tiles and manure digesters are another piece of this — how do we better handle manure to meet environmental needs more efficiently? What we’re doing isn’t really working. I agree entirely with you that this has to be a community effort. Finger pointing doesn’t work. 

Changemakers Alliance will be introducing this issue — along with several other topics — at the April 13 event. Become a Badass Member if you would like to be part of the conversations, solutions, and action.

The Link Between Agriculture and Water Quality

The bulk of Ring’s talk related to how to address agricultural pollution that impacts waterways. There are voluntary programs about sustainable approaches to use of fertilizers, pesticides, and manure-spreading. The Department of Agriculture has been working on the issues for more than 10 years. “There are questions about whether an agricultural certification program works, and whether the best management practices for farming work,” he said. “We still have nitrates in our streams and rivers and groundwater. An approach called One Watershed, One Plan is an effort by the Board of Water & Soil Resources to at least coordinate solutions; watersheds obviously cross county boundaries; it used to be that we had all these different county plans. This approach creates one comprehensive plan for each watershed.”

The Minnesota Pollution Control Agency, in the meantime, is trying to figure out how to handle pesticide-coated seeds that are no longer viable for planting. Pesticides are often embedded as coating on the seeds that are planted. Ring says the plant then becomes toxic to insects eating it. The Environmental Protection Agency estimates that only 5 percent of the pesticide on the seed coatings are actually taken in by the plant; the rest of it is going into the water and soil.

The Department of Natural Resources did a study of deer spleens in 2021; 61 percent contained high neonic concentrations. [Neonicotinoid pesticides — neonics —  are derived from the nicotine chemical in cigarettes. The DNR was responding to a 2019 South Dakota study with a captive deer herd where neonicotinoid exposure was associated with reduced fawn survival.]

Judging simply from the five different agencies with environmental accountability named in Ring’s talk, agriculture and its impact on the environment is a complex issue. “There’s no way you can just fix it,” Ring said. “Nitrate fertilizers, manure, and soil health have to be worked on from all different angles.”

Because of the nature of the interconnected ecosystem, one solution here can have unintended consequences years later. Ring pointed out that about 40 percent of corn growers are supplying the ethanol market, which leads to burgeoning increases in single-crop farming; there are not as many oats, alfalfa, and other crops as there used to be. This simplification leads to a depletion of soil organisms and nutrients. 

Crop rotation of different plants tends to support a more complex soil environment — a bigger variety of soil organisms and more organic material. Regenerative agriculture involves crop rotation combined with occasional animal pasturing for healthier soil. 

One of the water advocates who organized the forum told me that she had, 12 years ago, been a proponent of the ethanol marketplace as a way to reduce fossil fuel reliance. But now she realizes the impact this is having on soil health and water quality.

Ring makes the point that “we’re treating soil as the substance that simply holds up the plants. We put nutrients on it to make the plants grow.” In a healthier system, he says, natural soils are their own ecosystems. Organisms such as bacteria, fungi, and insects retain organic matter from material that has decomposed into the soil. This also is an effective tool to sequester carbon. 

“However, in typical corn growing, we plant the same crop, plow the field in spring and fall, treat it with herbicides to control other plants, and treat it with pesticides to control insects,” he said in follow-up communication with Minnesota Women’s Press. “The plowing leads to bare soil being exposed to precipitation and wind. The lack of organic material in the soil reduces its ability to retain moisture. Planting the same crop year after year leads to a vastly simplified soil ecosystem. The whole system is less resilient. If the soil contained more of its own nutrients, we would not have to use as much fertilizer.”

Different Soils, Different Issues

Minnesota’s geological diversity makes a difference as well, he said. For example, soils in the central part of the state are sandy, which doesn’t hold water and requires big efforts in irrigation. Agricultural toxins move through the sandy soil so easily that the groundwater for drinking is impaired. Park Rapids, had to pay $2.5 million for a new water treatment plant in 2015 due to nitrate contamination. Nitrate fertilizer and manure can lead to high nitrate levels in the water. 

In the northeast, complex processes in low-oxygen sediments can lead to increases in organic mercury (methyl mercury). That mercury can be taken up by aquatic organisms and magnified up the food chain (little fish eat algae, big fish eat little fish). This leads to high concentrations of mercury in the water and the fish we eat. 

One of the more well-known land issues is in southeastern Minnesota, where the porous karst landscape has led to groundwater contamination from agriculture. “Well owners must contend with elevated levels of nitrate, which has increased health impacts  — blue baby syndrome, cancers, pesticides in our rivers and wildlife,” Ring said. [See the earlier story in our water series here.]

In this area, he explained, the soil layer is generally thin; anything that is put on the soil can easily be washed off into the surface water. The surface water flows directly into the groundwater through sinkholes and channels in the karst bedrock. This means that putting fertilizer, manure, herbicide or pesticide on a field at the wrong time — maybe before a heavy precipitation event — can lead to large amounts of pollution entering surface- and ground-waters. This is especially the case for fields that are bare with no plants to slow down the runoff and take up the fertilizer. 

The Minnesota Center for Environmental Advocacy recently petitioned the EPA indicating that state agencies are not adequately protecting residents from agricultural chemicals in the water in the southeastern part of the state. The EPA agreed with them. State agencies have just released a plan for mitigating the situation; it is not clear whether the EPA will approve it or not.

Every year, the EPA requires the Minnesota Pollution Control Agency to develop a list of waters that are not meeting water-quality standards.


The Minnesota Pollution Control Agency’s latest map highlighting in red waters that are not meeting water-quality standards. The lines in purple have been delisted because they have been made safer since a previous survey.

The Pines to Potatoes Controversy

One large-scale ecosystem issue that illustrates the direct impact of agriculture started in 2015, with the “pines to potatoes” farm. Pine trees in central Minnesota were being cut down for a circular irrigation system that enabled the planting of uniform potatoes, which generally were provided to McDonald’s for French fries. A farm owner had purchased about 12,000 acres of Minnesota pine forests for cropland conversion, with another 15,000 acres in sight, in Becker, Cass, Hubbard, and Wadena counties.

A 2015 editorial by the Star Tribune focused on the decision of the then-commissioner of the state’s Department of Natural Resources to step into the “political crosshairs” by ordering an assessment to determine potential impacts. The number of well permits requested by the company required significant irrigation, putting pressure on groundwater supply to neighboring areas.

The editorial said the commissioner’s decision to step in should “serve as a timely reminder of the need to attract and retain strong leaders in government.” Shrunken White Bear Lake water levels, which were reported by MPR in 2012, illustrate that “the state’s waters are connected in ways scientists are just beginning to understand. High-capacity pumping, such as that from the 54 additional well permits requested by the private, family-run farm for the new potato fields, could have serious consequences elsewhere. It isn’t just recreation that’s at stake. Especially in rural areas, many Minnesotans rely on groundwater — a finite resource — for their drinking water.”