After yet another wet spring in eastern Nebraska, producers may be a little concerned about potential nitrogen leaching and denitrification. Of course, there may not have been much loss to denitrification. Even if there were issues with ponding after a 5-inch rain, if the soil temperature is cooler, it may not be warm enough to make the reaction occur. Meanwhile, the amount of denitrification and leaching will likely vary significantly across an individual field.
"Within a field, you have to look at it in a microclimate environment. Very rarely do we have a condition for nitrogen loss that takes up an entire cornfield," says Mike Zwingman, agronomy R&D manager at Central Valley Ag. "But what we do have is all these micro areas of the field, the depressions, the low spots, spots with compaction where we end up having some of those situations. That's what we need to focus on is how to recognize those situations."
In the latest Nebraska Notebook, Zwingman discusses some considerations affecting nitrogen loss and nitrogen uptake, including managing the sink and the source, the net effect of stand percentage, and when the corn was planted.
CVA is testing different planting dates — April 17 and 26, and May 12 — using the same hybrid in similar growing conditions. All represent a wide range of temperatures, and therefore, differences in net effect of stand percentage and root morphology.
"If we don't have the right root mass, we're not occupying the proper volume of soil," Zwingman explains. "If we're not occupying the proper volume of soil, we're not accessing as much water. If we're not accessing as much water, we're not taking up as much nitrogen. That's the chain effect of the soil temperature, root development relationship."
Editor’s note: You can listen to my conversation with Mike Zwingman on YouTube.