Dairy sheep farms in semi-arid rangelands: A carbon footprint dilemma between intensification and land-based grazing

In recent decades there have been significant changes in land use and production orientation in certain marginal agricultural areas in the southwest of Spain. The abandonment of rainfed cereal crops and their change of use as natural pastures grazed by milk sheep, have led to an improvement in the profitability of the farms, greater industrialisation and a positive impact on rural development. This paper calculates the carbon footprint (CF) of farms in the context of life cycle assessment with the objective to identify the system that accounts for the lowest CF while maintaining adequate levels of profitability and revitalising the rural environment. The data were obtained through surveys carried out on dairy sheep farms of different typologies, ranging from the semi-intensive farms with small grazing areas, to the extensive farms with large areas of natural pastures. Findings could help farmers evaluate the environmental impact of their activities, while at the same time provide consumers with valuable evidence to be used in further marketing actions. Greenhouse gas emissions vary from 1.77 to 4.09 Kg CO(2)eq/kg of milk, where the lowest values correspond to the most intensive farms and the highest values to the most extensive and least productive farms. Enteric fermentation, followed by feeding, are the emissions with the greatest impact. Enteric fermentation reaches its maximum value (52.22 % of the total emissions) in the most extensive farms. On other hand, this study found that carbon sequestration varies between 0.09 and 2.04 kg of CO(2)eq/kg of milk, a figure that can considerably reduce the carbon footprint calculation and justifies its inclusion in the Life Cycle Assessment.