Stream vs. Flat Fan Topdress Application of UAN in Winter Wheat.

With nitrogen use efficiency (NUE) in cereal grains only being 33% on average world wide and with the rising cost of and demand for fertilizer, it is imperative to employ better and more efficient methods of N application.  In recent years, as the price of solid fertilizer sources has gone up rapidly, the price of liquid N has increased at a much slower rate, now making it comparable to or in some cases cheaper than solid N fertilizer. As many producers move towards a split application of fertilizer due to increased cost effectiveness, more are utilizing liquid N sources for their fertilizer applications.  Because of this finding, a more effective method of topdress N application is imperative. The objective of this study was to determine the effect of different topdress application methods of liquid N fertilizer on N uptake of winter wheat [Triticum aestivum L.]. These trials were established in 2006 at two sites in Stillwater, OK consisting of 12 treatments arranged in randomized complete block design (RCBD) with three replications. Treatments consisted of a check plot and three methods of N fertilizer applications (flat fan UAN, streamer nozzle UAN and UREA) of 80kg N. This study will determine which method of topdress liquid N application is the most effective for crop production. Identifying optimum application method of liquid fertilizer is specifically important in variable rate technology which is one of the precision agriculture techniques being employed to increase efficiency, and maximize net returns of crop producers.