The push by Gov. Mark Dayton’s administration for a rule limiting some nitrogen fertilizer applications continues.
In early October, the Office of Administrative Hearings released the decision of the administrative law judge that the Minnesota Department of Agriculture has met the requirements of the rule-making process for the Groundwater Protection Rule. The judge also recommended the removal of several provisions of the rule that would have given the MDA commissioner some discretion to exempt or exclude some areas from the rule.
At this time, it is not known how the MDA will respond to the proposed changes, but the ALJ report is a clear signal that the rule will move forward.
Here are five important points for farmers to know:
1. Good nitrogen management is important wherever nitrogen fertilizer or manure are applied. Regardless of the outcome of the rule process, farmers need to take every practical effort to ensure that nutrients applied are used as efficiently as possible. Do you know how many pounds of nitrogen you applied per bushel of grain produced? This number, generally referred to as NUE (nitrogen use efficiency), is a good indicator, though one must use caution in comparing NUE figures from dissimilar fields. Good nitrogen management starts with knowing and addressing the factors that increase the risk of nitrogen loss on your fields. Good nitrogen management does not mean applying nitrogen at rates that limit crop yields.
2. Soils through which water moves readily require special attention. Fall applications on coarse-textured soils are already very rare, and beginning in the fall of 2020, they would be prohibited under the proposed rule. The same is true in the karst region of southeast Minnesota. Farmers should check out the interactive map at the MDA website and zoom in to view their fields to see if the fall prohibition will apply to them. Under the proposed rule, fall applications of commercial nitrogen fertilizer will be prohibited in all areas identified in purple or green, beginning in 2020.
3. Wellhead protection for public drinking water supplies is a top priority of the rule. If you farm in an area that is green on the MDA map, nitrate levels are already identified as elevated. Some of these areas will be subject to more strict requirements under the proposed rule as early as 2023.
4. Most cropland will NOT be subject to the new rule. There are about 20 million acres of cropland in the state. According to the MDA, about 100,000 acres will be covered by the public wellhead or drinking water supply management area (DWSMA) provisions, while about 2.6 million acres will be classified as vulnerable and simply subject to the fall commercial N prohibition at this time.
5. The rule will not affect manure applications, which are already regulated by the Minnesota Pollution Control Agency, with one exception: The more restrictive requirements affecting DWSMA areas include consideration of N supplied by manure when determining supplemental N applications, along with manure testing and manure management plans developed or approved by a qualified professional.
For more information, including the rule language, fact sheets and the map of affected areas, go to the proposed MDA Groundwater Management Rule webpage.
Formo is executive director of the Minnesota Agricultural Water Resource Center.