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