Reducing fuel load of key cheatgrass (Bromus tectorum L.) dominated range sites by the use of fall cattle grazing.

Abstract

ABSTRACT: Reducing cheatgrass fuels may be able to decrease the intensity or frequency of fires in the Great Basin. Using spring cattle grazing techniques to reduce cheatgrass fuels at large enough scales or high enough concentrations is impractical. However, cattle can be easily concentrated on cheatgrass during the fall, effectively reducing the amount of total fuel available during the next fire season. The effects of ranch-scale fall grazing of cheatgrass by cattle on fuel reduction, perennial grass growth, and cattle performance were examined. Yearly production and nutritional content are important to know before grazing. Cheatgrass nutrient content (7% protein and 61.5% TDN), during the dry years of 2007 & 2008, were adequate for the cows' nutritional needs. Fall grazing removed significant amounts of cheatgrass biomass during both 2007 and 2008. We found that cheatgrass was reduced without affecting the cattle's performance, or harming the perennial plants present, at least in the short-term. The cover of two perennial grasses even increased by the third treatment year, but there was a reduction in the seedbank of Sandberg bluegrass in both 2007 and 2008. Cattle preferred cheatgrass over perennials: 78.5% of cheatgrass biomass and 60.5% of perennial grass biomass was removed over the two year study period. After the second fall grazing period, cheatgrass density, cover and litter declined significantly under grazing whereas perennial density and cover were unaffected. Seed density of cheatgrass was significantly higher in the control treatment in 2007, but in 2008 the cheatgrass seed density declined in the grazed treatment. Cattle gained 1.2 and 1.75 pounds per head per day in2007 & 2008 respectively, and increased body condition by one quarter of a score in 2007, and four tenths of a score in 2008.