In-season N applications are boosting yields for Ryan Britt, a farmer and custom applicator from north-central Missouri, near Salisbury. Britt and his father, Randy, use a Hagie STS12 high-clearance sprayer and nitrogen toolbar with Ag Leader OptRx crop sensor technology.

“During the last three or four years, we’ve been consistently losing preplant N due to wet weather, but with the high-clearance capability, it’s opened up the N application window quite a bit,” says Britt, who uses smooth disc coulters on a front-mounted toolbar to dribble or inject N into the furrows. “We’ve seen some very good results from both our normal in-season and rescue-N applications.

This year, even with the dry summer weather, our yields were mostly above the historical averages, and I attribute that to the sidedress.”

Better technology and optimal timing have combined to both increase yields and protect water quality, Britt notes. “The OptRx system is configured to help grow more bushels, and that’s what it’s done for us,” he says. “Yet it’s also more environmentally friendly, because we’re not losing as much preplant N, and we’re putting N on when the plant needs it most. We bought the machine thinking it would help cut our N use, but we’ve realized now that our crops actually need more N than what we’d been applying earlier. And we’re not losing as much N to the environment this way like we once did.”

One area may be more prone to N loss than another, Jeurissen notes. “With N, we’re finding that we need more in spots, depending on soil type and soil conditions,” he says. “Some soil types typically need an extra shot of N later in the season more than other soils do.”

Britt says he’s considering making soil-based adjustments as well. “Depending on soil type, we’re looking at putting on a little more N upfront and maybe more than one postemergence N application afterward,” he says. “We’ve also been in a complete liquid N program for the last several years, but we’re looking at trying multiple N sources in the future. This year, we went to 75 lbs. liquid N per acre with preemergence herbicides and came back with the sidedress N for the rest, depending on the sensor-based rate.”

Britt adds that by working with his local agronomist, he continues to tweak his system. “I think we’re headed down the right road, but there’s still room for learning,” he says.

Jeurissen concurs that the learning curve with in-season N applications is just beginning. “We’re still in our infancy of optimizing this technology,” he says.