• Vegetative Response to Chemical Control of Broom Snakeweed on a Blue Grama Range

      Gesink, R. W.; Alley, H. P.; Lee, G. A. (Society for Range Management, 1973-03-01)
      All rates of picloram, either alone or in combination with low rates of 2,4-D, effectively controlled broom snakeweed on a blue grama range in southeastern Wyoming. Picloram also eliminated the low amounts of plains pricklypear present among the dense stands of snakeweed. Blue grama was initially injured by the 0.5 and 1 lb/acre rates of picloram, but needle-and-thread was damaged only by the 1 lb/acre rate. This initial injury to the grasses had a renovating effect upon the range, and, in combination with the elimination of undesirable plants, resulted in no table range improvement as measured 5 years after treatment. The study illustrates how herbicides may be a useful tool for selective manipulation of rangeland vegetation.
    • Wheatgrass Response to Seasonal Applications of Two Nitrogen Sources

      Sneva, F. A. (Society for Range Management, 1973-03-01)
      Fall, winter, and spring applications of 20 lb. N/acre as urea or as ammonium nitrate were applied in each of 3 years to two introduced grasses, crested and Siberian wheatgrasses, on Oregon's high desert range. Mature herbage yield increased with fertilizers, but there were no significant interactions with application date. Urea increased mean yield 3% more than did ammonium nitrate, but the increase may not be of practical significance. Crude protein concentration of mature yields, evaluated in 1 year only, was not influenced by either fertilizer or application time. Fall- and winter-applied N fertilizer increased available soil nitrate concentration in mid-April, but differences due to date and source of N were nil.