Greenhouse gas emissions and carbon sequestration in organic dehesa livestock farms. Does technical-economic management matters?

Livestock farming has been traditionally assessed by its economic figures, whereas the impact caused by their production models on the environment and on society have been largely disregarded. This paper analyses various organic cattle farming systems from the point of view of their technical-economic management, but also on the environmental impact caused by their greenhouse gas (GHG) emissions. Within this context, 34 organic meat cattle dehesa farms located in the southwest of Spain were studied. On the one hand, a principal component analysis devised four factors that explained the technical-economic management model of these farms in terms of their level of dependence on subsidies, production intensification, feeding practices and productivity. The farms were then divided into three clusters whose main differences came from the size of the farms, the intensification level and the joint rearing of cattle with other livestock species. On the other hand, GHG emissions and carbon sequestration levels for each of these clusters were calculated using the life cycle assessment methodology. The average GHG net emissions from the farms were 461.98 kg of CO 2 eq per ha (or 8.86 kg of CO 2 eq per kg of live weight of sold animal), with the largest and more extensive farms reporting 262.05 kg of CO 2 eq per ha (or 6.02 kg of CO 2 eq per kg of live weight of sold animal) and the smallest and more intensive farms resulting in as much as 697.49 kg of CO 2 eq per ha (or 11.18 kg of CO 2 eq per kg of live weight of sold animal). One of the most significant aspects of the study was the carbon sequestration capacity of dehesa extensive farms, which allowed these livestock systems to be in line with the preservation of the natural resources, animal welfare and the provision of ecosystem services. [Display omitted] • Sustainability of organic livestock farms is at risk due to low profitability. • C storage is a key ecosystem service of livestock systems to fight climate change. • Carbon sequestration in LCA reduces net emissions on extensive organic beef farms. • Livestock management on extensive organic farms improves climate change adaptation. [ABSTRACT FROM AUTHOR]