• Cattle Diets in the Blue Mountains of Oregon, I. Grasslands

      Holechek, J. L.; Vavra, M.; Skovlin, J.; Krueger, W. C. (Society for Range Management, 1982-01-01)
      Esophageally fistulated cows were used to determine cattle diets on grassland range in northeastern Oregon in 1976, 1977, and 1978. Idaho fescue, bluebunch wheatgrass, and Sandberg bluegrass were the most common species in the diets. Forb consumption declined while grass consumption increased with seasonal advance from late spring to fall. Food habits depended largely on phenological development of forage species. Forbs were preferred over grasses early in the grazing season; then after forbs reached maturity, cattle were selective for the plants that remained green. Diet similarities were compared between periods within years, and between years within periods. When diets were pooled into late spring, early summer, late summer and fall groups, late spring diets were least similar to the others. Diet variation from year to year was also less later in the grazing season. Utilization of Idaho fescue and bluebunch wheatgrass should be considered in grazing management decisions on grasslands in the Blue Mountains.
    • Fertilizer Effects on Above- and Below-Ground Biomass of Four Species

      Holechek, J. L. (Society for Range Management, 1982-01-01)
      Research was conducted in a greenhouse at Bozeman, Montana, and on coal mine spoils at Colstrip, Montana, in 1975 to determine production characteristics of four species when nitrogen and phosphorus 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 (Agropyron 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 three species when fertilizer was not applied. This may explain why this species has been successful in the Northern Great Plains.