Plan would create phased response to nitrates in groundwater, with a potential for regulatory action
Written by Jonathan Eisenthal
Six listening sessions have not turned up any earth-shaking critical comments about the Minnesota Department of Agriculture’s (MDA) proposed Nitrogen Fertilizer Management Plan, according to MDA officials. The comment period continues until Nov. 1, at which point Agriculture Commissioner Dave Frederickson will consider the comments and publish the final version of the plan. Adoption could come as soon as winter of 2014.
Through surveys, education and demonstrations, the plan aims to win widespread adoption of best management practices (BMPs) by farmers in areas where nitrate nitrogen exceeds drinking water standards. The mitigation process begins only when nitrates exceed standards in 10 percent or more of area wells and a significant number of farmers do not adopt BMPs. It is not clear what that figure would be, though officials mentioned adoption by 80 percent of farmers as a threshold.
The officials stressed that responses would be spearheaded by local advisory teams, and reflect management appropriate to the particular landscape, soil type and crops being raised.
Steve Sodeman, a participant in the development of the proposed plan representing the Minnesota Corn Growers Association (MCGA), attended the listening session in Rochester.
“Groundwater, drinking water are important issues, and we support efforts to improve water quality,” Sodeman said.
Using townships as the basic unit of mitigation efforts, the most immediate measure would involve the broadest survey of private wells conducted since Minnesota passed the Groundwater Protection Act in 1989.
In the next two to six years, MDA will offer voluntary testing to landowners in 250 to 280 townships where row crops are produced — locales that are considered “vulnerable” to nitrate-nitrogen rates exceeding the drinking water standard of 10 milligrams per liter. Based on experience, officials said they expect to test from 20,000 to 25,000 out of the 70,000 households with private wells in these areas.
Sodeman noted that these 280 townships still represent a very small proportion, and a very specific set of locations, among Minnesota’s agriculture areas. “This is not all of us,” he said. “It’s important to realize this is about groundwater, not surface water and not tile water. It’s really about farming in the sandy areas where nitrogen can filter down and reach aquifers.”
Based on the findings of the planned well survey, a mitigation phase would be determined for specific townships. Following the thrust of the 1989 law, mitigation efforts would rest most importantly on voluntary efforts by farmers to adopt BMPs, or where BMPs fail to curb nitrate levels in water, to adopt other management tools such as alternative crop rotations. In cases where enough farmers adopt BMPs to meet the plan’s requirements, a township would never enter the plan’s regulatory phase, regardless of the nitrate rates shown in ongoing testing of the affected area.
The plan calls for four phases where nitrates exceeding the standard are found. Phase 1 occurs in townships where more than 5 percent of the wells exceed the drinking standard, or where 10 percent of the wells exceed 7 mg/L. In such a case, a local effort to win widespread, voluntary adoption of BMPs would be the goal.
Where most farmers do use fertilizer BMPs, yet nitrate concentrations continue to exceed the standard in 10 percent of wells, the plan moves to phase 2, which continues voluntary efforts to mitigate. A team of local farmers and officials would continue efforts to understand and solve the problem, perhaps through voluntary adoption of alternative management practices like adding alfalfa because of its characteristic of scavenging nitrogen.
Doug Peterson, president of Minnesota Farmer’s Union, was present at the final listening session held in Roseville on Sept. 25, and asked, “So, no matter the PPMs (parts per million shown in the well testing) — if the farmers are working within the voluntary program, there will not be any regulation?”
“We have to document that practices are not being followed in order to move forward into a regulatory phase,” said Bruce Montgomery, an MDA fertilizer management expert.
Mitigation moves to phase 3, the first regulatory level of response, when excessive nitrates are found in 10 percent or more of drinking sources, and too few farmers adopt BMPs in a given township. In such a case, the plan requires a mandatory reporting of fertilizer practices by the farmers in the township. The plan calls for phase 4 when the non-compliance with BMPs continues and 15 percent or more drinking sources are affected. In that case, MDA would restrict fertilizer practices to those approved by a local team.
Among other points made in presentations at the session is the fact that the most fundamental aspect of BMPs are finding the optimal nitrogen rate — the most economically efficient rate that is also high enough to maximize yields — without placing any fertilizer in excess of that amount, which would be at risk of loss into groundwater. The officials acknowledged that even with use of optimal rates, some nitrogen would be lost due to no fault of the farmer because of weather and other circumstances.
“Farmers are taking an active role in dealing with groundwater issues,” Sodeman said. “Both MCGA, the Minnesota Corn Research & Promotion Council and AFREC — the research checkoff fund specifically for fertilizer — are investing money on research projects that deal specifically with the sand plains. We’ve partnered with potato growers to fund research there. When you partner, you get the most for your dollars.”
The Minnesota Corn Research & Promotion Council has appropriated $1 million of farmer-funded corn check-off dollars to create a position and fund the research activities of Dr. Fabian Fernandez, an assistant professor of nutrient management in the department of Soil, Water and Climate at the University of Minnesota. Dr. Fernandez will conduct research on a variety of subjects related to nitrate management, including sources, timing, rates and management processes.
The MDA, U of M and many local Soil and Water Conservation Districts are working cooperatively to advance knowledge about farm nutrients.
Montgomery noted that, to calculate the optimal amount of fertilizer to add, the presence of mineralized nitrogen in the soil is important to count.
“There is a 20-pound per acre N loss without any additional fertilizer on,” Montgomery said. “Typically we see a rate of 160 pounds per acre in southern Minnesota and lose about 30 pounds per acre. With U of M recommendations, that number can drop that by 17 percent. We will never get them to zero if we continue to row crop in Minnesota. But a 15 to 20 percent reduction is very doable. Our dependence on nitrogen fertilizer has stabilized very much over past 20 years. We can see a dramatic increase in the amount of yield per volume of fertilizer and that’s a success story for our farmers.”
One audience member asked how quickly regulatory action would occur where the conditions were met. MDA official Dan Stoddard gave an example of a three-year crop rotation: The farmer would be allowed time to adopt BMPs, and then have testing in different years through different phases of the rotation. Under that scenario, MDA would not take regulatory action until the ninth year (and only in the case where the farmer did not adopt BMPs).
Clearly not pleased with this response, the questioner wondered aloud why the MDA could not come in and compel a ban on fall fertilizer application or require the use of nitrogen inhibitors. While validating the concern about the goal of meeting health standards, Stoddard said that responses had to be local, and that not all approaches would be appropriate in all locations across the varied landscapes and soils of Minnesota’s farms.
The full 125-page plan can be viewed at the MDA website: www.mda.state.mn.us.