“Farmers are their own biggest stumbling block when it comes to nitrogen on corn,” says Tom McGraw, owner of Midwest Independent Soil Samplers, based out of Buffalo Lake, MN, Jewell, IA, and Clay Center, NE.
He wonders whether farmers can get over the psychological hurdle of 100% fall or spring N applications. “Historically, farmers have over-applied nitrogen to cover any potential losses that occur every year — sometimes large, sometimes small,” he says.
With the high cost of nitrogen and high corn prices, McGraw preaches that now is the best time to abandon single application of N on corn, “because split applications beat single applications hands down, every time. Growers remember the one time they couldn’t get the fertilizer on because of weather, and they should not let this event stop progress.”
McGraw has seen numerous attempts to make precision in-season variable-rate fertilizer applications work, using aerial photography and corresponding management recommendations. “While some variable-rate technology works well, it was always the aerial photo component that didn’t quite pan out. It was either too expensive, turnaround time was too slow or the photo resolution was poor,” he says.
“But now, John Deere has put enough muscle and the right technology behind OptiGro,” McGraw continues. (See story below.) “I was skeptical at first, but after working with it for a few years, they got the excellent photography and nitrogen management figured out. It’s far better than anything else out there. It will have a place in agriculture, but I just don’t know how long it will take farmers to adopt it.”
McGraw says he hopes that farmers who are trying it right now, after applying all their N before the season, will grasp the value of this technology. “They will see photos that prove actual N loss, at a time when corn needs it most — during the huge biomass growth stages of knee-high through ear development. And if they take the next step, applying liquid nitrogen with drop nozzles when corn is knee-high, then we’ll see growers begin to make the leap,” he says.
“The leap is to the ‘Holy Grail,’ where farmers put half the N on before or at planting, then come back with only what’s needed at knee-high stage,” he continues. “And with the whole OptiGro program only costing a little more than one bushel an acre, it’s very affordable — and that includes environmental benefits of less N leached from the soil profile each spring. But it takes a mind-set change.”