Financial and technical assistance is available to farmers in the Whitewater Watershed who would like to assess whether applying nitrogen through a side-dress application will improve yield this year.
With the amount of rainfall received to date this year, farmers may be concerned with the potential for nitrogen loss and how that might impact their yield. In a year without excessive rainfall in the spring, a single pre-plant application of nitrogen using University of Minnesota guideline rates is most often sufficient.
Looking at rainfall data from the National Weather Service shows over 10 inches of rainfall in the months of April and May for their observation location in Altura, about three inches above the 30-year average. Does that mean a side-dress nitrogen application is warranted?
Maybe, maybe not. During that time period, it wasn’t especially warm. Nitrification and denitrification are two key processes that can lead to nitrogen loss. They are driven by microbial activity and soil temperature. Through nitrification (which occurs faster with warmer soils), ammonium converts to nitrate. Ammonium can be held by the soil, nitrate can be leached with water. Nitrogen can also be lost through denitrification, which occurs when soils are waterlogged and warm. It could be that despite the level of precipitation, farmers are OK because of the cooler temperatures. There are other factors at play too, like soil type, manure history, the previous crop, etc. Plus, no one knows what the rest of June will bring.
If you’d like to see if an additional application is beneficial, consider participating in on-farm research. The results can help you fine-tune your management and improve your efficiency; there are financial and environmental benefits. Farmers and crop advisers are eligible to receive $400 each for their participation. In addition, you’ll receive soil-test results, and in-season imagery. The plots are simple to lay out and install.
If you’d like to learn more, contact Jake Overgaard, University of Minnesota Extension, at 507-457-6440 or firstname.lastname@example.org. For more details and a map of the project area, visit https://z.umn.edu/4db2.