• Delayed Germination of Cheatgrass Seed

      Hull, A. C.; Hansen, W. T. (Society for Range Management, 1974-09-01)
      Cheatgrass seeds germinate readily and usually near 100% shortly after collection. Generally, practically all seeds that fall to the ground germinate and plants emerge with favorable conditions in the fall, during the winter, or in early spring. In this study, an average of 692 cheatgrass plants/ft2 emerged the first year. In the same soil samples, 273 seeds/ft2 did not germinate but produced plants when these seeds were brought into favorable conditions in the greenhouse. When these ungerminated seeds remain in the soil-litter mass in the field, they germinate and emerge more slowly than seeds brought into the greenhouse. Seeds that remain in seedheads over winter germinate slowly but with a high percent when placed in a germinator. Nitrogen at 80, 160, 320, and 640 lb/acre caused the number of plants that emerged in the field to decrease slightly as the rate of fertilizer increased.
    • Range Plant Yield and Species Relationships in Natural and Partially Controlled Environments

      Bleak, A. T.; Keller, W.; Hull, A. C. (Society for Range Management, 1974-09-01)
      Competition and herbage production studies were established on soil columns (1.2 m square) that were isolated from the surrounding soil by heavy plastic sheeting to a depth of 1.4 m. Some plots received only natural precipitation; some 1-1/2 times the growing-season precipitation, and some 2/3 the growing-season precipitation. These different moisture levels had no significant effect on herbage yields during the 3-year period. Plots of alfalfa yielded most. Plots containing Kochia yielded as much as those containing alfalfa the first year, but not thereafter. Crested wheatgrass consistently outyielded Russian wildrye. Adjacent natural field plantings of the same species provided evidence that both alfalfa and Kochia had roots below the plastic barrier and were obtaining moisture from adjacent soil. Alfalfa was least affected and Kochia most affected by a close (5-cm) harvest height.