Abstract
Research was conducted in a greenhouse at Bozeman, and on coal mine spoils at Colstrip, Montana [USA], in 1975 to determine production characteristics of 4 spp. when N and P fertilizer was applied at a low rate and when not applied. Aboveground biomass, belowground biomass, and the root to shoot ratio of fairway crested wheatgrass (Agropyron cristatum), critana thickspike wheatgrass (A. dasystachyum), and fourwing saltbush (Atriplex canescens) were increased by fertilizer application. Root depths of crested and thickspike wheatgrass were increased by fertilizer application. Ranger alfalfa (Medicago sativa) responded differently to fertilizer application in the greenhouse and field experiments. Crested wheatgrass had a higher root to shoot ratio than the other 3 spp. when fertilizer was not applied. This may explain why this species has been successful in the Northern Great Plains.