Help corn have season-long access to nitrogen

Farm Forum

INDIANAPOLIS — Managing nitrogen is not a one-time event. For optimized crop growth and yield potential, nutrient management is as important in the middle of the season as it is at planting, says Eric Scherder, Ph.D., field scientist, Dow AgroSciences.

Growers should manage nitrogen so it is available when corn requires it throughout the season. One way to manage nitrogen is by applying it shortly after crop emergence or as a sidedress application.

“Nitrogen is something growers should be thinking about all season long, and thinking about how to manage it,” Scherder says. “When it comes to managing nitrogen, you want to stabilize fall or spring applications if that’s the bulk of your fertilizer, because that’s when you have the greatest loss opportunities.”

Corn experiences a critical period of nutrient uptake between the V5 and V8 growth stages. Therefore, stabilizing nitrogen is equally important for growers who make a sidedress application at the V5 or V6 stage, Scherder says, since corn continues to need large amounts of nitrogen for another 30 to 50 days. During that time, corn can’t afford to have a bad day.

“Growers doing a program approach with 60 percent nitrogen up front should consider applying nitrapyrin preplant,” Scherder says. “It keeps nitrogen available and gives growers more flexibility in the season if they are delayed by rain, so they aren’t starving the plant of nitrogen.”

Weather is one of the biggest challenges of sidedressing nitrogen. Rain before application makes it tough to get across the field, while heavy rain after application can make nitrogen vulnerable to leaching and denitrification. Nitrogen stabilizers, such as Instinct II and N-Serve, reduce leaching into groundwater and denitrification into the atmosphere, keeping nitrogen in the soil longer for corn use.

Whether growers are applying nitrogen preplant or weeks later around V4, using a stabilizer will preserve nitrogen so it’s there when the plant needs it.

For more information on keeping nitrogen accessible to corn, visit