Enhanced Nitrogen Fertilizers and Management Practices for Winter Wheat Production.

Nitrogen fertilizer is one of the major inputs for winter wheat production worldwide. However, several reports indicated that agronomic nitrogen (N) use efficiency is very low. In order to increase this efficiency, the use of enhanced nitrogen fertilizers and appropriate management practices (method, time and rate) have been recommended. The effect of enhanced N fertilizers in increasing yield and reducing N losses is affected by several factors including weather and soil properties. We investigated the effect of enhanced nitrogen fertilizers and management practices on grain yield and grain protein content of winter wheat and left over soil nitrogen for three years. The experiment was conducted in randomized complete block design with four replications in central Montana. Year effect was significant so results were analyzed and presented separately for each year. In 2011, fall broadcast application of regular urea with Agrotain® + N-Serve® (RUANSBF) resulted in 20% more grain yield than regular urea broadcast in fall (RUBF). Moreover, spring application of regular urea with Agrotain® + N-Serve® (RUANSBS) resulted in increased grain yield compared to other treatments. In 2012 (relatively dry season compared to 2011), fall application of the above treatment (RUANSBF) resulted in reduced yield compared to RUBF. However, in 2012, spring application of regular urea with Agrotain® + N-Serve® (NRUANSBS) produced more grain yield than regular urea broadcasted in spring (RUBS) for the same year. This was highly related to amount and distribution of precipitation in the area. Left over soil nitrogen after harvest was relatively higher for enhanced fertilizers compared to regular urea. This left over soil nitrogen could contribute as starting N fertilizer to the next crop. This paper discusses the different benefits of using enhanced nitrogen fertilizers and management practices in relation to grain yield, protein content and left over soil N.