Wednesday, November 7, 2007
299-6
Fall Applied Polymer Coated Urea for Wheat.
Kelly Nelson, University of Missouri, Greenley Research Center, PO Box 126, Novelty, MO 63460 and Peter Motavalli, Soil, Environmental, and Atmospheric Sciences, University of Missouri, 302 ABNR Bldg, Columbia, MO 65211.
Use of slow-release nitrogen (N) fertilizer for wheat may be a cost-effective management practice to increase crop performance and allow a single application in the fall. Research was conducted in Northeast Missouri from 2004 to 2007 to determine the impact of polymer-coated urea (ESN) rates and application timings on wheat grain and frost-seeded clover forage yields. Fall applied polymer-coated urea was similar to a split application in three of four years and was greater than a split application in one of four years. Fall applied polymer-coated urea had wheat grain yields 270 to 1480 kg ha-1 greater than urea alone in two of the four years. No differences in clover yield was observed in 2004, 2005, or 2007. Clover forage yield was reduced in 2006 when polymer-coated urea or urea alone were fall or split-applied at 112 kg ha-1. Differences in wheat response may be related to variation in soil drainage among years.