Effects of grazing on runoff and sediment yield from desert rangeland at Badger Wash in western Colorado, 1953-73

Abstract

Four different systems of livestock management were compared hydrologically during a 20-year study (November 1953-November 1973) in western Colorado. These systems were grazing by cattle and sheep from November 15 to May 15 each year, complete elimination of grazing, grazing by sheep from November 15 to February 15 each year, and grazing by sheep from November 15 to February 15 every other year. Grazing by both cattle and sheep from November 15 to May 15 each year was the standard grazing practice in the area at the beginning of the study. Complete grazing exclusion resulted in a reduction in runoff of about 25 percent during the period 1953-65 and an additional 25 percent during 1966-73. During the same periods sediment yield was reduced by 35 and 28 percent, respectively, for a total of 63 percent. A change in grazing use from cattle and sheep, November 15-May 15 each year, to sheep only at approximately the same utilization rate, November 15-February 15 each year, was accompanied by a reduction in runoff and sediment yield of about 29 percent. The same change in use, except that grazing was allowed every other year during the sheep grazing period, resulted in a reduction in runoff and sediment yield of about 20 percent. Recurrence intervals of annual runoff occurring on three soil types at Badger Wash are provided. These data may be applied to similar soils in areas of like climate and physiography shown on accompanying maps.