Composition and Yields of Native Grassland Sites Fertilized at Different Rates of Nitrogen

Abstract

Four range sites were fertilized at three different rates of nitrogen (33, 67, and 100 pounds nitrogen per acre) in southwestern North Dakota. Increasing the production of a range site with nitrogen fertilization is closely associated with the inherent production potential of the site. In general, greatest increases in total dry-matter yields for a given increment of fertilizer were observed at the 67-pound nitrogen application. Total basal cover was reduced by fertilization on the Vebar and Havre sites but increased on the Rhodes and Manning sites. In general, reduction in total cover was due to a decrease in cover of the blue grama grass. An increase in cover and density of western wheatgrass and the sage species was generally observed on all sites.