AgriGold agronomists (from left) Bob Berkevich, Terry Mente and Mike Kavanaugh participate in a panel discussion about various crop issues during the Specialty Crops Conference at the AgReliant Genetics Research Station. Much of the discussion centered around nitrogen issues.
AgriGold agronomists (from left) Bob Berkevich, Terry Mente and Mike Kavanaugh participate in a panel discussion about various crop issues during the Specialty Crops Conference at the AgReliant Genetics Research Station. Much of the discussion centered around nitrogen issues.

IVESDALE, Ill. — This year’s wet spring and the previous year’s drought has resulted in more questions than answers regarding soil nitrogen levels.

A panel of AgriGold agronomists from around the Corn Belt offered their views on this dilemma during the recent Specialty Products Conference at the AgReliant Genetics Research Station.

“I think my sales group that I work with is probably sick of me harping on nitrogen to them, but in my mind most of the acres in my area are going to need a little bit of extra nitrogen,” said Bob Berkevich, whose area includes southern Wisconsin and northwestern Illinois and parts of northern Iowa and Minnesota.

“Definitely the fall-applied acres do. If they were able to get it on in early spring, a lot of that nitrogen is probably lost.

“Even if it went down as 28 broadcast after planting, I still think a lot of that nitrogen has issue, too. But it’s so hard to come up with an exact formula, an exact science of how much could or couldn’t be out there.”

Among the considerations in looking at nitrogen needs is the field’s crop rotation and organic matter.

“You have a lot more potential to get the nitrogen released from organic matter in the soils that do have a little bit higher percentages,” Berkevich said. “Also, we have a lot of areas where guys put manure on, and that organic nitrogen in that will be released later on. I’m fully expecting this fall to see a lot of nitrogen deficient corn in my area.”

Jack Hardwick, AgriGold agronomist in southwestern Illinois and northeast Missouri, referred to an extensive study conducted by the University of Illinois last fall and this past spring.

“They probed one-foot and two-foot samples and assayed what leftover nitrate was in the soil. They found there were huge ranges of leftover nitrate and nitrogen in the soil — some low, some high,” he said.

“The glaring fact of that study was there was absolutely no correlation to (2012) yield levels, so your good, high organic soils in northern Illinois, where they had a really nice crop, those ultimately resulted in some of the highest nitrate samples.

“Nitrogen is a very complex nutrient, the fact that it goes into the plant in a couple different forms, ammonium form and also a nitrate form. Then throw in the fact that organic matter is mineralized and actually releases nitrogen into the soil gives you a little different spin.

“In southern Illinois, we had five- to 10-bushel corn, and some of our nitrate samples were virtually nonexistent due to light, low organic matter timber soil.

“We told a lot of growers not to factor leftover nitrogen into their nitrogen strictly due to the fact that it’s extremely volatile and even the university really don’t have a good grasp what type of numbers we actually have.”

AgriGold agronomist Steve Heightchew, whose area includes southern Indiana and parts of Illinois and Kentucky, said, “With the continued rains we’ve had nothing has been timely.”

“Sidedressing has gone on a little bit late in a lot of cases, so we’re fighting that. Of course, right after we’re putting it on, we’re getting even more rain and sitting there in saturated conditions,” he said. “It could be a great year to come back in and sidedress with some leg over-the-top applications to be able to pick up what we’re losing.

“We’re pushing the envelope in a lot of those cases and adding extra to our sidedress, but we’re putting it right into conditions that are going to be conducive to losing it again.”

Soil tests in eastern Iowa cornfields showed good nitrogen levels, according to agronomist Terry Mente, who serves that area.

“I think the way I approach the nitrogen thing is we’ve had a lot lower prices for corn in the past and what are we going to do with nitrogen when the price of corn is low? They’re going to put on just enough,” he said.

“When you get high-priced corn, there’s a big charge out there. Maybe my guys were different than anybody else, but they had a good charge out there.”

However, the downside is there are a lot of roots that aren’t going deep because “they didn’t have to,” Mente said.

“So are they catching it before the rain pushes it away? That’s the fine line right now, and I don’t think those roots are catching up to it at this point in time,” he said.

“A lot of wet spots that pushed it down anyway that aren’t showing up just yet. We’re starting to get that happy-go-lucky feel because these spots are getting covered up.

“You drive by on the highway and it doesn’t look as bad as it did a few weeks ago when those were bare. But those same spots are going to show up nitrogen deficient.”

He is a believer in split-application nitrogen applications.

“Put it on when the plant needs it. But in a real wet year, there are a lot of guys asking what the top end is they can put sidedress nitrogen on, and that scares me,” he said.

“Every once and while you bugger up some corn, depending on what stage it gets put on, depending on what Mother Nature does to it when you put it on. So I think we’re set up for a little bit of trouble in that realm.

“Once again, I’m all in favor of split application, but in a wet year, it’s going to bite you.”

Mike Kavanaugh, AgriGold agronomy manager, reiterated the need to have nitrogen available at the roots.

“In these wet years, we always just want to make sure we’re keeping nitrogen in the root system,” he said.

Kavanaugh said growers can conduct soil tests, and “we can try to monitor what’s actually in the soil all day long, but at the end of the day the crop is growing, you have shallow root systems and we need to make sure we’ve got adequate N in these root systems.”

Nitrogen application methods are key.

“This urea Agrotain thing has really caught fire over the last several years or putting just an extra 50, 60, 70 pounds of N on or going out with a Hagi and dropping a little bit of nitrogen on with the drops,” Kavanaugh said. “We’ve watched growers raise a phenomenal amount of corn that way.

“Something that’s been very key this year with all of these saturated soils and sealed-off soil types, just dragging an ammonia knife through the field and opening it up.

“Of course, if you’re going to do, you might as well in most cases put another 50 pounds of N on. The last thing you want to do is wake up at the end of the year and could have put another $30 an acre in made some big-time bushels.”

“A well-respected theory is for every day of saturation you have, you lose 2.5 percent of whatever is nitrate. When we start thinking of some of these soils being saturated for 30 days, that’s a lot of loss,” Hardwick added.

“We’re not just throwing darts and saying 50, 60, 70, 80 units. We’ve all worked through some of these numbers, and that’s kind of how we derive the equation — that 2.5 percent a day of whatever is nitrate.”