Each year the Nutrient Management Initiative (NMI) reports the results of the past season's on-farm field trials. Organizing and evaluating the results can be difficult with many variables to consider, including different farming practices, field variability, and weather patterns that can influence results. The purpose of NMI is to provide farmers with an opportunity to compare different nitrogen practices on their own farms and evaluate other trials from the same region. The NMI can go a long way to help relay the positive efforts farmers are already making on their farms to the public, and serve as a great tool for discussion on ideas to help benefit yields and water quality in Minnesota.
The NMI reports dating back to 2009 are located in the Minnesota Digital Water Research Library. Direct links to the most recent reports are listed below.
Despite drier than normal conditions in portions of the southeast and south west, USDA NASS showed the 2022 crop year was met with corn yields ahead of the previous season here in Minnesota. This same trend was largely reflected in the NMI data, with higher than previous season average yields across treatments in three of the four regions where trials were performed.
Across the state, the average low nitrogen rate treatment was 151 lbs N/ac, which resulted in an average yield of 209 bu/ac. The average high nitrogen rate treatment (typical for the farmer doing the trial) was 188 lbs N/ac, which resulted in an average yield of 214 bu/ac. Of the 48 individual trial locations, 32 (67%) showed a no significant difference between resulting treatment yields – meaning reducing the N application rate did not negatively impact yield.
The most popular fertilizer product across the state was urea or urea with other products (e.g., ammonium sulfate) applied in the same time window. That said, anhydrous ammonia was the primary N source on the largest number of trials in the Southwestern region (33% of trials), and urea ammonium nitrate (UAN – 28%) was the primary nitrogen source on the largest number of trials in the South Central region (43% of trials).