Southern corn management has unique challenges
Farmers in the southeastern U.S. are planting more corn this year. Some are merely bumping existing acres, while others are taking a stab at an altogether new crop.
In making this transition, they'll face a handful of challenges unique to the region, both in getting the crop in the ground and getting a good stand moving into the summer.
University of Florida Extension agronomist and cropping systems specialist David Wright says coastal soil composition makes it necessary to apply a starter fertilizer either immediately before planting or after initial emergence.
"Some hybrids respond dramatically, some very little. Most of that is due to the type of root growth we've found," Wright says of starter fertilizer. "We recommend ripping under the row, because we've got a natural compaction layer in the coastal soils. If you run into a dry period without ripping under the row, you've got about three days before you're going to need a rain or irrigation. With ripping under the row, that extends the window a few more days, because you have rooting depth of 12 to 16 inches deep."
Even with a well-prepared seedbed like this, one unfamiliar territory for new corn growers is seed depth. Mississippi State University crop production specialist Erick Larson says it's important that growers understand what it takes to get seed well-positioned for early growth.
"Precise seed spacing and planting parameters are going to be a lot different than cotton and soybeans -- corn needs to be planted deeper. We're not nearly as concerned with seed spacing and seeding depth with those other crops," Larson says. "A lot of our farmers are used to using a lot higher planting speed with those other crops.
"Sometimes, it's hard to hold that throttle back."
When and how to apply the right amount of nitrogen, phosphorous and other nutrients during the growing season is another issue with which some infrequent or new corn growers may have trouble. Larson recommends early nutrient testing and more frequent soil testing during the corn growing season compared to other crops. Keeping a close eye on these conditions is crucial in the southeast, where the number of days suitable for nutrient application and integration are fewer than in the Corn Belt.
"Anytime they enter a crop rotation system, I always encourage folks to soil-test more frequently," Larson says. "The only thing is because our soil conditions are typically a lot wetter here in the spring than in the Corn Belt, they won't have time to incorporate things like nitrogen and phosphorous into the ground with tillage because it's too wet. The number of days we have in the spring suitable for fieldwork will be limited -- normally, it's less than 12 days a month and sometimes six to eight."
Wright says he recommends Florida growers to apply split nitrogen applications, one at planting, another when the corn is 10 to 15 inches tall and a third when the corn is 24 to 30 inches tall.
"Each nitrogen application should have sulfur in it here for the sandy soils," Wright says. "Plus, we recommend adding half a pound of boron for soil carbohydrate transfer. That's not really a problem in the Corn Belt."