Just Keep Swimming

Show-Me Life

Crop management decisions are tough after flood.

Published on: June 11, 2013

As I leaned down to take a photo of a soybean plant submerged in water, all I could think of was the animated Disney movie Finding Nemo. Then I began to sing the angelfish Dora's famous line---"just keep swimming, just keep swimming."

While soybeans are resilient, the reality is that there are feet upon feet of water burying some of these plants and the likelihood of recovery is getting slimmer with each passing rain shower. And the corn, well, there will be replant.

Decisions, decisions
In the latest University of Missouri Extension southeast region farm management newsletter, extension agronomist Anthony Ohmes offers some insight for farmers facing tough crop management decisions. The concern with flooding or saturated soils, he says, is oxygen depletion for both soybeans and corn. However, corn, particularly small seedlings, is the most vulnerable. Survival will be dependent on length of flood, air temperatures, and in the case of germinating seeds to some level - corn hybrid.

REPLANT: This field of corn in southern Warren County will have areas of replant this summer.
REPLANT: This field of corn in southern Warren County will have areas of replant this summer.

Ohmes explains that germinating and emerging corn requires oxygen. Soil oxygen in flooded fields is depleted within 48 hours. Air temperatures below 77 degrees Fahrenheit will aid in survival during the flooded period. Ohmes says research indicates emerged corn, prior to sixth leaf stage, can survive up to 4 days when air temperature is less than 77 degrees Fahrenheit. As air temperatures increase, this time can reduce from 4 days to 1 day. In addition to oxygen depletion, concerns associated with flooding are seed rots, seedling blights and crazy top.

Once water recedes from farm fields, growth will resume within 3 to 5 days. Ohmes says this is the time farmers need to be out in the fields evaluating corn stand and plant survivability. Farmers need to look for healthy radicle root and coleoptile that is white to cream color. They also need to conduct stand counts and utilize replant decision guides to make a determination whether to keep the existing stand. MU offers a guide to help with the process. It is MU guide 4091: "Corn and Soybean Replant Decisions."

WEARY: Rural residents faced road closures and flooded farm fields last week. The Missouri River is finally receding providing some relief to smaller creeks.
WEARY: Rural residents faced road closures and flooded farm fields last week. The Missouri River is finally receding providing some relief to smaller creeks.

There is additional information on flooded corn courtesy of Iowa State's IPM article: "Corn Survival in Flooded and Saturated Fields".

Destined to farm
Often, it is hard to see the soybeans and corn through the muddy floodwaters. Still one thing I know is Missouri farmers will continue working the land. They have been through floods and come back fighting. They are like Dora in the movie—destined to continue their quest no matter how many distractions or disasters are thrown their way. So, for one more season farmers will "just keep swimming," until they run on dry ground. Then they will plant.

LAKE FRONT: Farm fields were turned into lakes as rivers and creeks could not handle the deluge of water and spilled over the banks.
LAKE FRONT: Farm fields were turned into lakes as rivers and creeks could not handle the deluge of water and spilled over the banks.