1. Nitrogen needs after heavy rains.
Early-planted corn is reaching its rapid nitrogen uptake period. Have heavy and consistent rains reduced the amount of available nitrogen in those fields? Emerson Nafziger, University of Illinois crop scientist, says that is unlikely.
“A more immediate question is whether the pale green or yellow spots in fields need nitrogen applied now in order to prevent serious yield loss. Rapid loss of color in places where water stands comes from loss of root ability to take up nitrogen, not from loss of nitrogen from the soil,” he said, adding that this is because parts of fields where roots are in aerated soil are not showing deficiency.
The extent to which roots of plants in wet or flooded soils will recover will not be known until soils dry and re-aerate enough for root function to return. Adding nitrogen before then will do nothing for the plants, and if soils remain wet or flooded, some of this nitrogen will be lost before the plant has a chance to take it up, Nafziger said.
Read more about the impact flooded soils may have on nitrogen uptake.