This part of the rule is a combination of voluntary and regulatory efforts designed to work with local farmers and their agronomists to find solutions that are tailored to their specific situation. There are four levels in Part 2 of the rule. Levels 1 and 2 are voluntary, and Levels 3 and 4 are regulatory. Under Levels 3 and 4 the Commissioner of Agriculture will work with local advisory teams to consider the appropriate regulatory requirements.
DWSMAs that fall under Part 2 of this rule will be monitored and will move up or down according to changes in water quality. DWSMAs may only move up one mitigation level at a time. For example, a DWSMA will never go from Level 1 to Level 3 in a single cycle.
Fields located in DWSMAs that contain 5.4 to less than 8 mg/L nitrate-nitrogen fall under Level 1. At this mitigation level the MDA will encourage the voluntary adoption of the University of Minnesota’s Best Management Practices (BMPs) for nitrogen fertilizer.
Fields located in DWSMAs that are at or exceed 8.0 mg/L nitrate-nitrogen or have been at or exceeded that level at any point during the previous 10 years, or that are projected to exceed 10 mg/L nitrate-nitrogen in ten years, will be included in Level 2. The MDA will promote the implementation of BMPs and conduct surveys to assess the adoption rates of BMPs.
A Level 2 site will progress to Level 3 if one of the following occurs: 1) after three growing seasons the BMPs are not adopted on 80% of the cropland acres (excluding soybean acres); or 2) after three growing seasons the residual soil nitrate below the root zone increases; or 3) after three growing seasons or the estimated lag time, whichever is longer, the nitrate concentrations continue to increase. The Commissioner of Agriculture – in consultation with a local advisory team – would then require landowners to implement best management practices, testing, and educational programs.
If nitrogen in the public water supply well exceeded 9 mg/L nitrate-nitrogen for any three samples in the previous 10 years; or after three years the residual soil nitrate below the root zone increases; or after three years or the estimated lag time, whichever is longer, the nitrate levels continue to increase, then the DWSMA would be given a Level 4 designation. The Commissioner of Agriculture – in consultation with a local advisory team – could require landowners to implement additional practices beyond best management practices. These practices would be determined on a site specific basis following guidance outlined in MN Statutes Chapter 103H.275 Subd. 2(a). However they may not include restrictions on the primary crop or restrictions on fertilizer rates below the low end of the University of Minnesota recommended fertilizer rate range.
Progress Under Way – In areas where progress is being made, the Commissioner of Agriculture could grant a one-time exemption for each level before moving the area to the next level of regulation.
Fertilizer Technical Unit Supervisor
Pesticide & Fertilizer Management Division