Managing Livestock Stocking Rates on Rangeland
Project Range Care , 1993

Cox, J.R., Cadenhead, J.F.

Watersheds are important reservoirs and sources of water for agricultural, industrial, and human uses. Population growth and expansion are expected to make increasing demands on water resources. To meet this increasing demand, a major environmental concern is focused on the physical impacts of watershed management practices that may impact the hydrologic cycle (Figure 1). Recently, concerns of nutrient and bacterial contamination have also become important to the public. The impact of livestock grazing on watershed parameters has become a national resource management issue. Often the information is based on emotion or misinterpreted data. This paper will assess the impacts of livestock grazing on watershed parameters. Improperly managed grazing animals can indirectly cause contamination of water by damaging vegetation to a degree that erosion occurs. This nonpoint-source pollution could have a major impact on quality of the state’s water supply because grazing lands make up a large portion of the watersheds in Texas. Rangeland accounts for about 60 percent of the Texas land area (40 million ha). In addition, grazing land classified as pastureland, which receives more intensive management than rangeland, includes 11 percent of the land area (7.2 million ha). Livestock grazing affects watershed properties by altering vegetation properties and by the physical action of the animals’ hooves. Reductions in the vegetation cover may: increase the impact of raindrops; decrease soil organic matter and soil aggregate stability; increase surface soil crusts; and decrease water infiltration rates.