• Seasonal Yield and Chemical Composition of Crested Wheatgrass in Southeastern Wyoming

      Rauzi, F. (Society for Range Management, 1975-05-01)
      Herbage yields, crude protein levels, and mineral concentrations of crested wheatgrass were influenced by phenological development and distribution of spring precipitation at the Archer Substation near Cheyenne, Wyo. Crude protein levels and mineral concentrations in the crested wheatgrass declined with plant maturity. Amount and distribution of the precipitation enhanced or retarded phenological development. Calcium uptake per acre by the crested wheatgrass was greater during a wet spring, but calcium concentration per unit of dry matter was higher during a dry spring.
    • Influence of Soil-Water Potential on the Water Relationships of Honey Mesquite

      Easter, S. J.; Sosebee, R. E. (Society for Range Management, 1975-05-01)
      Thermocouple psychrometry was used to measure soil and plant water potentials of honey mesquite growing under irrigated and nonirrigated field conditions. The trees growing on the irrigated area experienced more internal stress (average minimum water potential, -30.9 bars) than trees growing under nonirrigated conditions (average minimum water potential, -19.4 bars). The water potential in the trees and transpiration rates adhered to a very distinct daily pattern. Minimum water potential occurred about noon in the trees growing on both sites. During the growing season, the average transpiration rate of the trees on the irrigated area was 9.59 X 10^-5 g cm-2 min-1, while the average transpiration rate for those trees growing on the nonirrigated area was 7.15 X 10^-5 g cm-2 min-1. The trees growing under irrigation produced 2 times more foliage than the trees growing without irrigation. Consequently, the greatest amount of soil water depletion occurred under irrigation. The results of this study indicated that water loss via transpiration in honey mesquite growing in shallow soils or on upland sites (relatively dry situations) is not as great as the amount lost from trees growing on bottomland and on riparian sites.
    • Grazing Marginal Ranges in the Southwest

      Hanrahan, M. P. (Society for Range Management, 1975-05-01)
      The sensitive rangelands of the Southwest are a delicately balanced arrangement of thin soils, sparse vegetation, and limited precipitation. Grazing must be carefully regulated in order to protect the delicate ecosystem. Steep slopes and rugged terrain require special consideration.
    • Germination Characteristics and Chemical Control of Horehound

      Stritzke, J. F. (Society for Range Management, 1975-05-01)
      Less than 35% of the seed collected in October from mature plants of horehound (Marrubium vulgare L.) would germinate. Seventy-eight percent of the seeds germinated after 1 month of west storage at 0°C. From 20 to 25% of the seeds were still dormant after 4 months of storage at the three conditions tested. Better than 90% control of the existing horehound plants was possible with both 2,4-D and silvex at a rate of 2 lb/acre.