One of the largest natural resource districts in Nebraska is poised to establish a new rule for fertilizing by requiring use of nitrification inhibitors in certain nitrogen applications, which would affect some 3,000 farming operations.
Acting on concerns over growing nitrate contamination in groundwater over the past few years, Upper Big Blue Natural Resources District is proposing to give farmers three fertilizer application options: 1. Anhydrous ammonia applied between Nov. 1 and Feb. 29 must also include a nitrification inhibitor; 2. Nitrogen fertilizer applied on or after March 1 and before planting at a rate greater than 150 pounds per acre must also include a nitrification inhibitor; or 3. Pre-plant nitrogen fertilizer applied on or after March 1 at a rate less than 150 pounds per acre does not require a nitrification inhibitor.
As an alternative to using a nitrification inhibitors, which delay the conversion of nitrogen fertilizers to the nitrate form and reduces nitrogen loss, Option #3 allows the farmer to apply a lower rate of fertilizer before planting, and then apply additional nitrogen if needed after planting, when an actively growing crop can utilize it.
District officials have sent out notices to 56,000 residents of a public hearing scheduled for March 1 at 1:30 p.m. in the York City Auditorium. They point out that several communities in the area have found it necessary to construct new wells to comply with state and federal drinking water standards. Some communities have built or are considering treatment plants. Many rural residents have also replaced wells or installed private water treatment systems.
Rod DeBuhr, district water department, said that nitrification inhibitors change the structure of bacterial counts in the soil so it slows down the conversion of ammonia nitrates. “The products are used with both liquid and granular fertilizers to slow down the process of the conversion, which occurs only when nitrogen is in a nitrate form,” he offered, adding that he understands that it would cost about $9 per acre for a typical application.
“Actually it’s a bigger issue than just how it affects the farmer. Groundwater contamination is affecting entire communities,” DeBuhr noted. “The only thing we’re asking is that producers try to use fertilizer responsibly. In most cases it saves fertilizer that isn’t washed away in the growing process.”
Since 1996, the NRD has required that farmers wait until Nov. 1 to apply anhydrous, and to wait until March 1 to apply other formulations of nitrogen fertilizer. In some parts of the district where groundwater nitrate is the highest, farmers are required by existing regulations to attend training classes, take soil samples, and calculate crop nitrogen needs.
Upper Big Blue, located to southeastern Nebraska, is one of 23 districts established in 1969 by the legislature that were granted the authority to enact rules and regulations within each district to conserve natural resources.