Sustentabilidade dos sistemas brasileiros de produção em pastagem de bovinos de corte

Abstract

The growing interest of the world population for socio-environmental issues in production systems has led to greater concern for rethinking practices and attitudes in order to minimize human impacts on the planet. In the Brazilian context, these debates have a strong impact on the agricultural sector, more specifically on the beef cattle production, due to their economic and social relevance, the use of large tracts of land and their influence on global warming through the greenhouse gases emission (GHG) by animals. In this sense, in the present work it was proposed to analyze: (1) the evolution of Brazilian meat production and quality and its environmental impacts, between 1994 and 2018; (2) different environmental impacts of beef cattle production systems typical of the Amazon, Cerrado, Pampa and Pantanal biomes; and (3) the relationship between productive intensification, GHG emissions and biodiversity conservation in breeding systems characteristic of these biomes. The evolution of meat production and quality, and Brazilian territorial occupation was determined based on data published by official institutions. Environmental impact estimates were performed using the life cycle analysis (LCA), implemented by SimaPro® software, in accordance with ISO 14040 and 14044. Productive improvements gave rise to the "New Brazilian Miracle", which consisted of an increase in meat production, quality and exports between 1994 and 2018, with a reduction of 19,3% in pasture area and of Brazilian beef carbon footprint from 49.6 to 25.6 kg CO2 eq. / kg eq. carcass (CWE). GHG emissions from meat production were 13.92; 12.10; 14.62 and 21.18 kg CO2 eq. / kg of live weight gain (GPV), and the agricultural land use was 89.30, 87.94, 158.84 and 148.27 m2a / kg GPV, respectively, in the Amazon, Cerrado, Pampa and Pantanal systems. The Cerrado system presented higher values of terrestrial acidification, depletion of metals and fossil fuels, freshwater and marine ecotoxicity and particulate matter formation. The Pantanal system was more impacting in water depletion, freshwater and marine eutrophication and the photochemical oxidants formation. In all cases human toxicity and terrestrial ecotoxicity were negative. Urban areas occupation, ozone depletion, natural land transformation and ionizing radiation were not significant after normalization. The confrontation of productive intensification and biodiversity conservation in breeding stage showed that the mitigation of environmental impacts in a timely manner may make other possibilities unfeasible. These findings allow a greater knowledge of the peculiarities of each biome, as well as a more adequate targeting of efforts to identify alternatives to mitigate environmental impacts and improve their socioeconomic performance. In this sense, a convergence of efforts in favor of national production becomes particularly important in the panorama of 2050, when Brazil, with its abundance of natural resources, will be able to participate in a preponderant way of the global challenge of increasing food production.