MSU typically recommends corn N rates based on a yield goal of 1.3 lbs. N/bu. of grain yield. However, Larson says research shows you can use 10-15% less N than the standard recommendation if you are growing corn on lighter, sandier soil (similar to most of Huddleston's production).

“NITROGEN RECOMMENDATIONS for corn in the South are based totally on corn-yield goal because our warm, wet winters keep N from carrying over from year to year,” he says. “This is different from the Midwest, where consistently cold, dry conditions effectively stop N loss during the winter.”

He says using proper N sources, timing and application method are often more important than N rate to crop utilization and corn-grain production in the Midsouth. He suggests split application methods to reduce the likelihood of considerable N loss due to wet weather before crop use.

Corn uses less than 10% of its N before rapid vegetative growth begins, usually from late April to mid-May, depending on planting date and seasonal temperatures. Therefore, growers can use N more efficiently by applying only a small portion just after plants emerge.

“Add the bulk of N fertilizer just before the growth spurt, when the plants need it most,” says Larson. “Apply no more than one-third of the total N near planting/crop emergence, then the second application about 30 days later when the corn should be about 12 in. tall or at the V6 growth stage.”

As in the plan used by Huddleston, Larson says growers who have not applied their intended N allotment may be forced to apply N by air because the corn may be too tall to permit ground equipment. “Ammonium nitrate is the preferred N source for aerial application because it is not subject to volatilize, compared to urea,” he says.