In a favorable year, weather and nitrogen combine to contribute more than 50% of the total yield. The weather, in fact, influences every aspect of nitrogen loss, availability and utilization by the plant. Whether it is a drought year or wet year, both play huge roles in nitrogen availability for crops. Continued research and technology, however, are ongoing, providing us with the tools to better mitigate the impacts of all weather-mediated stresses.
The goal of timing nitrogen application to corn is to supply an adequate amount when the crop needs it without supplying excess that could be potentially lost. This application process, as we all know, can be easily interrupted by Mother Nature on an hours notice. If the weather does interfere with the originally planned in-season application, a quickly implemented backup plan also can help avoid significant nitrogen deficiency and yield loss.
To help reduce losses, nitrogen “stabilizers” or “additives” can be applied along with fertilizers. A couple stabilizers I want to highlight would be Instinct and N-Serve. These products are nitrification inhibitors that act against bacteria responsible for nitrification, slowing the conversion from ammonium to nitrate and reducing the loss. Stabilizing with N-Serve and Instinct greatly reduce both leaching and denitrification protecting nitrogen in the root zone.
Corn generally requires over half its total N supply between V8 and tasseling (VT), so it may be recommended to sidedress N by V4 to V6 are to provide some margin of safety in case weather and soil conditions delay N application or N movement to the roots.