Emergy evaluation of grazing cattle in Argentina's Pampas

Argentina has a tradition of grazing livestock and the Pampas region produces 61% of the total beef cattle, with more than 80% allocated to internal consumption. Potential for expanding exports has created incentives for increasing production, yet national decisions should include an assessment of natural resources and environmental impacts of the grazing system. The aim of this study was to evaluate the complete system of grazing cattle in Argentina's Pampas in an environmental and economic context. Emergy analysis is used to assess the potential for long-term, sustainable cattle production including indicators of performance and environmental sustainability, with focus on all sources of input energy and the energy value of outputs. Rainfall contributes 61% of the total emergy to the grazing system. Natural pasture depends most highly on local renewable resources (85%) and less than 4% on purchased inputs. In contrast, sowed pasture and maize are 41 and 35% dependent on purchased inputs. Results showed the grazing system to be environmentally sustainable with a low impact on the environment. Yet specific subsystems where grazing cattle depend for part of the cycle on improved sowed pasture or on maize have a relatively high dependency on external inputs and moderate use of local non-renewable resources. Natural pastures have the highest environmental sustainability and the lowest load on the environment, due to low losses of soil organic matter. Appropriate management strategies are available for grazing livestock systems, yet government regulations need to provide incentives to ensure future production stability and economic returns while minimizing adverse effects on the environment. One method to achieve this is recognizing and rewarding farmers for the emergy contributions of the environment. (c) 2006 Elsevier B.V. All rights reserved.