Developing Improved Nitrogen Recommendations for Dryland Hard Winter Wheat in Northeast Oregon.

In the Pacific Northwest, the production of non-traditional market classes such as hard red and white wheat may increase grower profitability compared to soft white wheat.  However, nitrogen (N) management issues with hard wheat are complex, as growers must meet market expectations for grain protein and quality.  In 2006, a project was initiated to develop management guidelines to optimize N applications for both yield and protein of hard red and hard white winter wheat.  Experimental sites were located at Pendleton, Lexington, and Helix, Oregon to capture a range of environments within the projected hard wheat production region of eastern Oregon.  A randomized complete block design with four replications was used.   Varieties evaluated included three hard red, one hard white, and a soft white control.  Nitrogen treatments consisted of 12 N rates split between fall and spring applications.  Fall N applications ranged from 0 to 336 kg N ha^-1 and were made in 56 kg N ha^-1 increments at Pendleton.  At Lexington and Helix, fall N applications ranged from 0 to 168 kg N ha^-1 and were applied in 28 kg N ha^-1 increments.  Spring applications consisted of 56 kg N ha^-1 at Pendleton or 28 kg N ha^-1 at Lexington and Helix.  Approximately 112 kg N ha^-1 applied in the fall maximized grain yield at Pendleton.  Only 56 kg N ha^-1 in the fall was required to maximize grain yield at Lexington and Helix.  Additional N was required for grain protein at some sites. Spring N had little to no effect on grain yield or protein.  Current results indicate that it may be possible for hard wheat growers to reduce N applications without reductions in grain yield or protein.  Additional research is being conducted to confirm these results and develop new fertilizer N recommendations for hard wheat production in Oregon.