by CHRIS ROGERS
Farms surrounding Altura and Utica will be asked, then required to limit their use of synthetic nitrogen fertilizer, under a new state rule taking effect this year.
State agencies have long governed large farms’ use of manure. Now, the Minnesota Department of Agriculture’s (MDA) nitrogen fertilizer rule — also known as the groundwater protection rule — will regulate the use of synthetic fertilizer for the first time ever in Minnesota. Synthetic fertilizers such as anhydrous ammonia are commonly used to feed growing corn plants and other crops, but they are also a source of nitrate pollution in local groundwater and drinking water. Altura, Utica, and Elgin are among 23 Minnesota cities and public water systems affected by the new rule because of elevated levels of nitrates in their wells.
Winona County Farm Bureau President Glen Groth said the new rule shouldn’t create a serious hardship for most farmers, though he expressed concern about the potential for more onerous requirements in the future. Some environmental groups have criticized the rule as not going far enough to prevent pollution and protect private well owners.
The new rule has two parts. First, it passes a ban on the application of synthetic fertilizer in the fall in virtually all of Southeast Minnesota — something Groth said most local farmers don’t do anyway. Second, it establishes a four-leveled system in which people farming land near polluted public wells are first asked, then required to use best management practices (BMPs).
BMPs are ways of using fertilizer that minimizes the risk of pollution, such as following University of Minnesota (U of M) application rates for how much nitrogen to put on fields, splitting fertilizer applications into multiple smaller rounds instead of one big application, and using nitrification inhibitors, chemicals that prevent nitrogen from being converted to nitrate and limit leaching of nitrogen out of the top soil.
“Most BMPs are things farmers could easily comply with if they aren’t complying with them already,” Groth said. “By and large I think most farmers are following those recommendations,” he added.
At the first and second levels of the rule’s four-tiered system, BMPs are voluntary. At the third and fourth levels, the MDA can order farmers to follow BMPs.
Last Wednesday, the MDA placed Altura and Utica at level two because recent tests found nitrate levels of over 5.4 micrograms per liter in the cities’ drinking water. In 2018, Altura’s highest test result was 6.8 micrograms per liter. Utica’s was 18 micrograms, from an emergency well not used for drinking. The federal health limit for nitrate in drinking water is 10.4 micrograms. Consuming too much nitrate can make infants seriously ill and has been linked to increased risk for a variety of health conditions in adults, including cancer, according to the Minnesota Department of Health.
Farms within each cities’ drinking water supply management area (DWSMA) — land close enough to the cities’ wells to affect their water quality — are subject to the rule. Altura’s DWSMA is relatively small. Utica’s DWSMA covers hundreds of acres south of Utica.
In each DWSMA, the MDA will form local advisory teams consisting of local farmers and agronomists who will recommend which BMPs are best suited to the area. Then, the MDA will use those recommendations to make a final decision on what BMPs should be required. MDA Fertilizer Management Unit Supervisor Larry Gunderson said advisory teams would likely be formed sometime this year. A final decision on BMPs for Altura and Utica might not be made until 2021. Farmers would then have three years to voluntarily implement the BMPs on 80 percent of the cropland in the DWSMA — not including soybean fields. If the BMPs aren’t implemented or if nitrate levels in groundwater get worse, the MDA can move the DWSMA up to level three and order farmers to follow BMPs. It would likely be four or more years from now before such an order could be made.
“There’s a period of time where we allow voluntary practices to be adopted, and if those nitrogen fertilizer BMPs are not adopted or the groundwater gets worse, then we proceed to regulation,” Gunderson explained.
If BMPs haven’t been fully implemented, but groundwater quality isn’t getting worse, why would the MDA order farmers to follow BMPs? If the MDA waited for pollution to exceed the health limit, it would be too late to do anything about it, Gunderson answered. “By the time it gets there, it’s too late to bring it down,” he said.
The Daley Farm of Lewiston owns several fields in the Utica DWSMA. Ben Daley said the new rule won’t have much effect on his family’s farm. “We’re already limited on the amount of nitrogen we can use on our land because of the size of our operation,” Daley said. Because of the Daleys’ livestock operation has over 1,000 animal units, it’s already subject to state regulation of its manure management plan. That plan is focused on manure, but also controls the amount of other fertilizers that can be used on fields. “I know we’re already 20 pounds [per acre] under what crop farmers can do,” Daley stated. Smaller livestock farms and crop farmers might be more affected by the new rule, Daley noted.
The Post contacted other landowners in the Utica DWSMA who declined to comment.
General farming practices aren’t the only potential source of nitrate pollution. The MDA delayed applying the new rule to the Plainview area because of evidence that a a few specific point sources of pollution, as opposed to widespread farming practices, are to blame for elevated nitrate levels in Plainview, according to Gunderson.
Groth’s main concern about the new rule was that it might be used to push more onerous practices than standard BMPs. In addition to the standard BMPs, the MDA recognizes alternative practices that can be used to mitigate nitrogen pollution, such as no-till or limited tillage, cover crops, and precision agriculture. Groth said that precision ag and conservation tillage are becoming fairly common, but he wouldn’t want to see farmers ordered to plant cover crops. Cover crops are great, but it would not be feasible for every farmer to implement them, Groth argued. Cover crop seeds cost money, and planting them takes time at crucial points of the season. “If you’re in the position of a younger farmer or a farmer that’s having some tougher financial constraints, you may not be able to go out and spend that extra $20-$25 per acre if you’re farming 500 acres,” he said, referring to planting costs. If a farmer’s harvest runs late into the fall, he or she may not have time to get cover crops established before frost kills them, Groth stated. In that situation, “It won’t have accomplished anything, but you’re mandated to have that expense,” he said. There are ways to plant cover crops while cash crops are still growing, but it requires special equipment, he noted.
“I think a lot of it might depend on who is on those advisory committees,” Groth stated. “If we stick with what the U of M and surrounding states’ research has recommended, it won’t be that heavy of a lift. If all of a sudden we have environmentalist groups calling the shots, that could put us in a different boat.”
Several Minnesota environmental and water quality groups have criticized this rule as not going far enough, especially because it only applies to public water systems and does not address people living in rural areas who rely in private wells for their drinking water.
The national Environmental Working Group (EWG) released a report last week highlighting nitrate pollution in Minnesota drinking water and saying the nitrogen fertilizer rule “may be too little, too late.”
“Minnesota’s new nitrate rule is a necessary, important first step, but much more needs to be done – and soon,” EWG Senior Economic Analyst Anne Weir Schechinger said in a statement. “As written, this rule has too many loopholes allowing for continued contamination of tap water from farms.”
Gunderson said the MDA is still working to monitor pollution in private wells and get farmers outside DWSMAs — who are not subject to the rule — to voluntarily practice BMPs.
When it comes to tracking how farming practices on the surface affect aquifers underground, there’s one wrinkle the MDA has not ironed out yet: lag time. Lag time is the amount of time it takes contaminants on the surface to reach aquifers deep underground. It can vary greatly from place to place and from aquifer to aquifer in Southeast Minnesota. In some places, surface water flows into shallow aquifers in a matter of hours. Elsewhere, the lag time may be over 10 years. In the Altura and Utica DWSMAs, the MDA does not know what the lag time is. “It is something we will need to determine,” Gunderson stated.
Or not. While one part of the rule requires the MDA to wait for the lag time — whatever amount of time that is — before bumping a DSWMA up from level two to level three, the rule also gives the MDA an alternative. If the MDA conducts residual soil nitrate tests, it does not need to wait for the lag time. Those soil tests measure the amount of nitrates that have leached down below the root zone, where plants can no longer absorb nitrogen but where groundwater can carry it into aquifers. The idea is that nitrate found below the root zone is likely headed for aquifers sooner or later, Gunderson explained. “If we see that [nitrate levels] are increasing over time, then we’re going to understand that the BMPs are not effective,” Gunderson said.
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