Released: March 17, 2005

Time Growing Short For Top Dressing Nitrogen on Wheat

MANHATTAN, Kan. – For wheat producers who have thought about top dressing nitrogen on this year’s wheat, the time is now, according to a Kansas State University agronomist.

“To maximize the benefit of spring top dressing nitrogen it should be completed before the wheat joints, which usually occurs from mid-March to mid-April across the state,” said Jim Shroyer, wheat production specialist with K-State Research and Extension. “Jointing is the stage of development when the wheat starts stem elongation to push the growing point or head above ground and when the number of spikelets per head are determined. Kernels develop from the spikelets, so it’s important to apply nitrogen before the crop’s yield potential has been set.”

Shroyer said that the week or two of warm weather Kansas experienced in February got the wheat moving and sped its development. That, combined with windy conditions and problems applying the topdress nitrogen because of wet soils kept some farmers from getting nitrogen applied.

“But farmers are pushing to get the nitrogen on as quickly as possible, especially in the southern part of the state where jointing has already started,” he said.

Where wheat hasn’t jointed yet, nitrogen should be applied soon, the agronomist said. But even if wheat has just started to joint and needs nitrogen, farmers should apply it as soon as possible.

“They just need to realize the wheat won’t get the biggest bang for the nitrogen buck, but it will help yields,” Shroyer said. “With nitrogen prices being quite high, some farmers may decide it’s too late for a nitrogen application if the wheat has already started to joint. Well, again, if the wheat needs nitrogen and you don’t apply it, yields are going to be hurt.”

He said liquid or dry nitrogen fertilizer sources are equally effective for top dressing, but price and adaptability to individual operations should be the basis for selecting the nitrogen source.

It’s common practice to use liquid nitrogen as a carrier for some herbicides, such as Finesse, Ally, and Amber to achieve weed control, he said, in addition to providing needed nitrogen for the wheat crop in a single pass. The common broadleaf weeds to watch are mustards, henbit and wild buckwheat.

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K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.

Story by:
Jim Shroyer
jshroyer@oznet.ksu.edu
K-State Research& Extension News