Author
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Angell, Raymond |
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Submitted to: Journal of Range Management
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/6/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Crested wheatgrass is the most commonly seeded grass on rangelands in the western United States. It can be high quality forage if managed properly. Because it is well adapted to grazing, intensive rotational grazing may be a way to gain optimal benefits from this forage. However, there is little available information regarding response of crested wheatgrass or associated shrubs to intensive rotational grazing. This study compared conventional grazing with steers to rotational grazing at stocking rates up to twice normal. Results indicate that stocking rate increases may be possible with short duration rotational grazing, but that doubled stocking rate has potential to encourage increased shrub density, which would decrease forage production over the long term. This new information will benefit land managers, both public and private, who manage the several million acres of crested wheatgrass in the western U.S.. It provides guidance for setting stocking rates, and indicates that moderate increases in stocking rate are feasible using intensive rotational grazing systems. Technical Abstract: A four year study was conducted to investigate effects of continuous and short duration grazing on standing crop and tiller density of crested wheatgrass. Pastures were stocked in early May and grazed for about 45 days for continuous (SL) grazing, and in 2 periods using a 3-day graze, 27 day rest sequence simulating a 10-paddock short duration rotation (SDR) grazed pasture. The base stocking rate was 0.6 AUM/ha on SL grazed treatments. Base stocking rate on SDR treatments was 0.6, 0.9 and 1.2 AUM/ha. Mean tiller density was greatest on 0.6 AUM/ha SDR paddocks (p=0.10), at 707 tillers/m2. Tiller density on 1.2 AUM/ha SDR paddocks did not differ from continuously grazed units, at 640 tillers/m2. Pregrazed standing crop was lowest in 1.2 AUM/ha SDR paddocks, averaging 439 kg/ha. Density of Wyoming big sagebrush increased across years, but did not vary among treatments. Sagebrush plants <15 cm tall decreased on SL paddocks, but consistently increased under short duration grazing, primarily at the highest stocking rate. It is concluded that SDR at conventional stocking rate did not decrease tillering and yield of crested wheatgrass, however SDR at doubled stocking rates has potential to limit crested wheatgrass productivity over time. |
