The Influence of Ammonium Nitrate on the Growth and Yield of Crested Wheatgrass on the Oregon High Desert¹

Abstract

Synopsis Spring yields of crested wheatgrass were more than doubled by application of 30 pounds per acre of N and were directly related to April and May temperatures but inversely related to the amount of fall and winter precipitation over a 4‐year period. Annual yields were directly related to fertility rate, and to the amount of precipitation received in the preceding November 1 to June 1 period. Counting residual response, the 20 pounds per acre fertility rate returned 25 pounds of herbage per pound of N applied.