As the temperatures warm and the days become longer, winter wheat will begin to greenup. According to Peter Scharf, University of Missouri Extension State Soil Fertility Specialist, the ideal time to apply nitrogen fertilizer to winter wheat is just before jointing. Jointing is the time when a short hollow space can be found at the bottom of the main stem where it meets the crown of the plant. Wheat plants take up most of their nitrogen once they are actively growing in April and May. Applying fertilizer early in the season allows more time for nitrogen loss from the soil to occur.
Two years of data from a project conducted by Scharf in Columbia resulted in a 10 bushel per acre yield increase when nitrogen was applied to winter wheat in mid-March over mid-February nitrogen applications. Sixteen years of research projects resulted in a 6.8 bushel per acre increase in yield when nitrogen was applied in March over those where nitrogen was applied in February. On average, the optimum nitrogen fertilizer rate in all of Scharf’s studies was 79 pounds of nitrogen per acre resulting in 67 bushels per acre yield.
Scharf recommends using polymer-coated urea as the nitrogen source if you choose to apply prior to mid-March. This coating slows the release of the fertilizer. The one time Scharf recommends applying nitrogen at greenup rather than in mid-March is to promote tillering. If there are not at least two good tillers per plant at greenup, applying nitrogen at this time can promote tiller development. Polymer coated urea should not be used in this situation so the fertilizer will be released quickly.
For more information contact Valerie Tate, agronomy specialist for MU Extension, by email at
email@example.com or by phone at 660-895-5123. University of Missouri Extension programs are open to all.
Valerie Tate is an agronomy specialist for MU Extension.