Wet Weather Affects Corn Nitrogen Management

Wet Weather Affects Corn Nitrogen Management
The wet weather has been general in nature across the region. However, there are some areas that missed some rain events allowing growers to plant in the narrow window of time.
Corn nitrogen management will be critical with the rain events we have had. Warm saturated soils will cause nitrogen to denitrify which the nitrogen goes off into the air. This process commonly occurs in all soils and does not have any environmental concerns. Our atmosphere contains a lot of nitrogen.
Despite all the research, corn color is the best indicator if the corn plant has adequate nitrogen. Yellow plants indicate lack of nitrogen. We can use meters to measure the color but often we can visually see if corn is deficient.
It is important to keep in mind the size of the plant when looking at the plant for color. Plants less than a foot in height are to hard to judge. After this height, nitrogen deficiency becomes more apparent.
If plants are yellow, supplemental nitrogen may be needed. Look for high risk areas such as fields that have had standing water, fall applied nitrogen, and those poorly drained.
Another technique to determine if corn is nitrogen deficient is to apply additional nitrogen in a small area within the field. This will provide a reference to gauge nitrogen color against. The size can range from a application being doubled to that of a ten foot by twenty foot strip that is hand applied. If you are going to do this, get this applied so you have a reference strip available in time.
For more information, contact Wayne Flanary, Regional Agronomist, University of Missouri Extension at 660-446-3724.