Once the floodwaters recede, Arkansas growers will have to navigate a checklist of issues to assess the scope of replanting, the need for nitrogen and how to cope with one of their toughest enemies: germinating pigweed.
“The effect of the water on nutrient availability will vary among nutrients, soils and the degree of wetness, whether the soil is flooded, saturated or just wet,” said Nathan Slaton, professor and director of the soil testing lab for the University of Arkansas Division of Agriculture. “The greatest impact of wet or flooded soils will be on nitrogen that was applied before planting several weeks ago on corn. The possible situations are many, from little to no loss of nitrogen, to complete loss.”
The longer the nitrogen has been out on the fields and the wetter the conditions, the more nitrogen will have been lost, he said.
“The first step growers need to take is to make an assessment and see what fields were flooded and others saturated, and decide whether to replant all or just part of the fields,” he said.
“Some situations will be black-and-white and some in the middle,” he said. “Working with their county agent and consulting extension agronomists will be the best way to assess those questionable situations.”
Meanwhile, pigweed has thrived in the wet conditions.
“Pigweed is going ahead and germinating,” said Bob Scott, extension weed scientist for the University of Arkansas Division of Agriculture. Where crops were planted, wet fields prevented some growers from applying residual herbicides, a key control tool for pigweed.
For those who did, “a lot of the residuals that are underwater are gone for the most part. It’s washed off and dissipated,” Scott said.
Even worse, for those who had weed-clean fields, “there are new flushes of weeds of all kinds moving in where these places have flooded,” he said. “There will be a lot of Gramoxone, Ignite or other burn-down herbicides used in fields that used to be clean.”
The replanting also means growers will have to be more vigilant down the road, especially in corn.
“The later the planting, the more expensive the insect control will be,” Scott said. “Not to mention the need to irrigate corn later in the summer when it’s 150 degrees outside.”
Mary Hightower is with Media Relations with the Cooperative Extension Service of the University of Arkansas, Division of Agriculture.
