Increasing the Efficiency of MAP and Urea Applied to Winter Wheat in Montana with AVAIL and Nutrisphere-N.

NutriSphere-N® (N-N) has been used in many areas to promote better nitrogen use efficiency.  AVAIL® has been used to treat phosphate fertilizers to improve P availability in the soil as well as tissue P uptake. N-N and AVAIL were evaluated on hard red winter wheat (Triticum aestivum) production at 3 sites near Conrad, Montana. Urea (0, 40 and 80 lb N/ac) with and without N-N and monoammonium phosphate (MAP at 0, 15, and 30 lb P₂O₅/ac) with and without AVAIL were applied in 5 x 5 factorial treatment combinations (treatments=25).  Yield increases were observed over the three site years for both N and P. There is strong statistical evidence (p=0.02) that N-N increased wheat yield and the effect tapered off as the N rate increased.    There was also significant evidence (p=0.10) that AVAIL increased the yield of winter wheat at low N levels.  Under the dryland conditions of these studies, N-N and AVAIL did not have a significant effect on crude protein even though there was a trend for the N-N and AVAIL combination to have the highest crude protein concentration.  Increased in wheat yields with NutriSphere-N and AVAIL should provide encouragement to growers, crop advisors and federal agencies that N-N applied to urea and AVAIL applied to MAP will help improve N and P performance and fertilizer efficiency for winter wheat production in Montana and other areas of the Northern Great Plains.