Late-Season Nitrogen Deficiency Showing in Several Fields

CORN ILLUSTRATED: Trend extends across a wide area.

Published on: Sep 3, 2013

One question analysts and agronomists had about the 2013 corn crop was whether it would have enough nitrogen to finish filling kernels, making them plump, and adding to extra yield. When the August crop estimate came out, apparently traders thought the answer was "yes." Corn rallied only slightly even though the forecast was slightly less than the trade expected.

Now, agronomists are saying that for many fields, the answer is likely "no" – there wasn't enough N to finish the crop. It could reduce kernel size, although it's too late to influence number of kernels. So the top end of the yield curve is in jeopardy.

Actually, Purdue University Extension agronomist Bob Nielsen says it may be a combination of nitrogen levels, dry weather and even too much heat very late that is ganging up on corn plants trying to finish the season.

Run out of gas: The nitrogen dial is reading low inside these plants, partly because roots are having a harder time accessing N in drier soils.
Run out of gas: The nitrogen dial is reading low inside these plants, partly because roots are having a harder time accessing N in drier soils.

Agronomists who were worried early thought the crop might not have enough N to finish since it was so wet early, and some N that was applied was likely lost. That's still true, most agronomists say.

However, Nielsen believes the dry weather is making it worse. Even if there is still N in the soil, the roots are having a harder than normal time getting to it because soils are dry, and roots don't grow well in dry soils.

So if the roots can't supply it, plants will pull it from leaves to finish as many kernels as they can in good fashion. That leads to aborted tips, and may also lead to lower than normal kernel fill and weight unless conditions turn around quickly.

Paul Burgener, marketing specialist for Farm Progress Companies, says that just a couple of weeks ago he told farmers the corn price at harvest could have a '3' in front of it due to a big crop. Now he doubts that will happen. He doesn't see corn dipping below $4 even at harvest if this pattern continues.