Last Season's Flooded Spots Lead to This Season's Ugly Corn

Did you have fields with wet holes and bare spots in 2015?

If so, those spots are probably showing up again this year – in the form of corn with stunted, purple or striping in the leaves.

Fallow Syndrome is the label given to these symptoms – standing water prevents crop growth and destroys the soil health. Without plant growth, there is a lack of a fungi called mycorrhizae. Mycorrhizae are a beneficial class of fungi that colonize the roots, and in exchange for carbon from the plant they help the plant absorb more nutrients and can also help enhance the root’s ability to access more water. When there is no plant material the year before the mycorrhizal population is low.

When we experience cool/wet or hot/dry spring conditions the lack of mycorrhizae can be exhibited by a phosphorous purpling or zinc striping on the young corn plant. Soils with limited fertility or coarse textured soils that have flooded will tend to show the symptoms more frequently. Although fallow syndrome is not a death knell to the field it is common to see lower yields and wetter corn in these areas at harvest.

The good news is there are remedies to the problem:

  1. Establish a cover crop or plant material in the flooded areas even late in the year. This helps the mycorrhizae population recover from the flooding.
  2. Banding P the following year can help.
  3. Apply mycorrhizal inoculants at planting.

When we experience flooding in one year we can do something to prevent the effects of that damage to carry over the next year and continue to cost us income.