2008 Year in Review

From the Fields

With current prices of nitrogen fertilizer, it is imperative that wise decisions regarding its use, especially in the fall, are made. The use of nitrogen to help break down corn residue and amount of fall nitrogen needed for winter wheat was addressed in the recent University of Illinois Pest Management & Crop Development Bulletin.

Will nitrogen fertilizer, such as urea ammonium nitrate solution, applied on the residue this fall help breakdown corn stalks? Research has shown no benefit in fall application of nitrogen to increase the decomposition of corn residue in order to improve corn planting and nitrogen for the following corn crop. Typically, low temperature, and not nitrogen levels, is the limiting factor for microbial decomposition of corn residue.

What is the fall nitrogen need of winter wheat? Given the late seeding of winter wheat, it is critical that the crop becomes quickly established. However, the amount of nitrogen needed in the fall is typically less than 30 pounds per acre. The reason for this is that the crop normally has a short time for growth before it becomes too cold. And, it is not desirable to promote excessive vegetative growth in the fall because of potential disease problems in the spring. If the soil has a large potential to supply nitrogen, fall application prior to seeding winter wheat is not necessary.

University of Illinois suggests a nitrogen credit of 10 pounds per acre when wheat follows soybean. The preferred method of nitrogen application is to apply most of the needed nitrogen by topdressing in the spring right before crop green-up. The total amount of nitrogen required by winter wheat depends on the amount of soil organic matter and the presence of a legume seeding. Details are shown in the Illinois Agronomy Handbook. They are also available at University of Illinois Extension offices.

by  Editor, theCity1.com
October 26, 2008