Avaliação das pegadas de carbono e hídrica da produção de manga no submédio do Vale do São Francisco

Abstract

Brazil is one of the world’s sixth biggest exporter of mango, and the semiarid region in the sub-middle of San Francisco Valley has the largest share of the national production with a share of 76% of the fruit production. In view of the several environmental impacts caused by large-scale crop production, this study evaluated the carbon and water footprints caused by the conventional production system in this agricultural region for 1kg of packed mango; The data was collected in the field and compiled, having been considered the processes of land use change, seedling production, production and transport of fertilisers, pesticides and other inputs, mango orchard production, agricultural mechanised operations and post-harvest phase; the phases of distribution, consumption and waste disposal were disregarded. The impact assessment methods chosen were: IPCC, 2007 100a for the category climate change, ReCiPe Midpoint (H) for freshwater and marine eutrophication, USEtox for human toxicity – cancer and non-cancer effects – and freshwater ecotoxicity, and Pfister et al (2009) for water scarcity. The dominance analysis showed that the fertilisers production caused most of the impact on climate change, followed by the mango orchard production and mechanised agricultural operations. Regarding the water footprint, however, the mango orchard production caused the most significant impacts all categories, having also significant impacts the post-harvest processes, the agricultural operations and the fertilisers production. Lastly, we compared the impacts caused by the conventional system and a conservationist green manure system the six fist years of production, that showed that, for 1 kg of mango, the conventional system caused more impacts for three of the six categories chosen for the water footprint (marine eutrophication, human toxicity – cancer and non-cancer effects), while the green manure system caused the most impact on the other three. Both systems had a positive impact on climate change, though the green manure treatment sequestered more carbon. However, there was a large difference between the systems yield and that affected the results considerably; when reassessing the impacts for one hectare instead of 1 kg, the conventional system impacts significantly more for all chosen categories.