Impact of the intensification of beef production in Brazil on greenhouse gas emissions and land use

摘要: Brazil has the largest herd of beef cattle in world, estimated at approximately 200 million animals. Production is predominantly pasture-based and low input hence time to slaughter long, which promotes high methane (CH4) emissions per kg product. The objective this study was investigate impact increasing animal productivity using fertilizers, forage legumes, supplements concentrates, on greenhouse gases (GHGs) five scenarios for production Brazil. A life cycle analysis (LCA) approach, from birth calves mature animals ready farm gate, utilized Tier 2 methodologies IPCC results expressed equivalents carbon dioxide (CO2eq) carcass produced. Fossil CO2 emitted supplements, feeds fertilizers included standard LCA techniques. first four were based solely pasture, ranging degraded Brachiaria pastures, through a mixed legume/Brachiaria pasture improved N-fertilized pastures Guinea grass (Panicum maximum). Scenario 5 most intensive also an but with 75-day finishing period confinement total ration (TMR). Across 1 increase digestibility promoted reduction intake unit weight gain concomitant CH4 emissions. For estimation nitrous oxide (N2O) excreta, emission factors Cerrado region postulated lower dung than urine much long dry season region. greatest intensification systems 7-fold area necessary 320 45 m2/kg carcass. Carcass increased 43 65 Mg across 5, be reduced 58.3 29.4 CO2eq/kg Even though grass-legume scenario (3) (scenarios 4 5) GHG similar as legume N2 fixation had no fossil-fuel cost. large source uncertainty construction such LCAs lack data enteric grazing tropical forages.