Monteiro Alyce, Barreto-Mendes Luciano, Fanchone Audrey, Morgavi Diego P, Pedreira Bruno C, Magalhães Ciro A S, Abdalla Adibe L, Eugène Maguy
Université Clermont Auvergne, INRAE, VetAgro Sup, UMR Herbivores, F-63122 Saint-Genès-Champanelle, France; University of São Paulo, Center for Nuclear Energy in Agriculture, Laboratory of Animal Nutrition, Av. Centenário, 303, São Dimas, 13400-970 Piracicaba, SP, Brazil.
Université Clermont Auvergne, INRAE, VetAgro Sup, UMR Herbivores, F-63122 Saint-Genès-Champanelle, France.
Sci Total Environ. 2024 Jan 1;906:167396. doi: 10.1016/j.scitotenv.2023.167396. Epub 2023 Sep 30.
Intensification of livestock systems becomes essential to meet the food demand of the growing world population, but it is important to consider the environmental impact of these systems. To assess the potential of forage-based livestock systems to offset greenhouse gas (GHG) emissions, the net carbon (C) balance of four systems in the Brazilian Amazon Biome was estimated: livestock (L) with a monoculture of Marandu palisade grass [Brachiaria brizantha (Hochst. ex A. Rich.) R. D. Webster]; livestock-forestry (LF) with palisade grass intercropped with three rows of eucalyptus at 128 trees/ha; crop-livestock (CL) with soybeans and then corn + palisade grass, rotated with livestock every two years; and crop-livestock-forestry (CLF) with CL + one row of eucalyptus at 72 trees/ha. Over the four years studied, the systems with crops (CL and CLF) produced more human-edible protein than those without them (L and LF) (3010 vs. 755 kg/ha). Methane contributed the most to total GHG emissions: a mean of 85 % for L and LF and 67 % for CL and CLF. Consequently, L and LF had greater total GHG emissions (mean of 30 Mg COeq/ha/year). Over the four years, the system with the most negative net C balance (i.e., C storage) was LF when expressed per ha (-53.3 Mg COeq/ha), CLF when expressed per kg of carcass (-26 kg COeq/kg carcass), and LF when expressed per kg of human-edible protein (-72 kg COeq/kg human-edible protein). Even the L system can store C if well managed, leading to benefits such as increased meat as well as improved soil quality. Moreover, including crops and forestry in these livestock systems enhances these benefits, emphasizing the potential of integrated systems to offset GHG emissions.
强化畜牧系统对于满足不断增长的世界人口的食物需求至关重要，但考虑这些系统对环境的影响也很重要。为了评估以草料为基础的畜牧系统抵消温室气体（GHG）排放的潜力，对巴西亚马逊生物群落中四种系统的净碳（C）平衡进行了估算：单一栽培马兰杜栅状草[臂形草（Hochst. ex A. Rich.）R. D. Webster]的畜牧系统（L）；每公顷种植128棵桉树、与三行桉树间作栅状草的畜牧-林业系统（LF）；先种植大豆然后种植玉米+栅状草、每两年与畜牧轮作一次的作物-畜牧系统（CL）；以及每公顷种植72棵桉树、CL + 一行桉树的作物-畜牧-林业系统（CLF）。在研究的四年中，有作物的系统（CL和CLF）比没有作物的系统（L和LF）生产了更多可供人类食用的蛋白质（分别为3010千克/公顷和755千克/公顷）。甲烷在温室气体总排放中占比最大：L和LF平均占85%，CL和CLF平均占67%。因此，L和LF的温室气体总排放量更高（平均为30 Mg COeq/公顷/年）。在四年中，按每公顷计算，净碳平衡最负（即碳储存）的系统是LF（-53.3 Mg COeq/公顷），按每千克胴体计算是CLF（-26千克COeq/千克胴体），按每千克可供人类食用的蛋白质计算是LF（-72千克COeq/千克可供人类食用的蛋白质）。如果管理得当，即使是L系统也可以储存碳，带来肉类增加和土壤质量改善等好处。此外，在这些畜牧系统中纳入作物和林业可增强这些益处，凸显了综合系统抵消温室气体排放的潜力。
