Abstract

The potential of tree component neutralization was studied to understand the relationship between livestock, forest production and greenhouse gas (GHG) emissions. The objective of this work was to evaluate the carbon balance in a silvopastoral system including semi-intensive dairy farming and to quantify emissions per unit milk produced in Visconde do Rio Branco, Minas Gerais state, Brazil. The tree component of the silvopastoral system was a hybrid of Eucalyptus grandis x Eucalyptus urophylla in a semi-intensive production system, including Brachiaria decumbes as forage grass and crossbred dairy cow. Carbon stock was calculated from the estimated wood volume with forest inventory data, wood density and wood carbon content factor for tree species. Livestock (enteric fermentation and animal waste management), electricity, fuel consumption, nitrogen and limestone fertilization were the GHG emissions considered using emission factors. The carbon balance was obtained by comparing annually the GHG emissions with the increase of this element. The Average Annual Carbon Increment (IMAC) was 7.631 Mg CO_2e ha⁻¹year⁻¹ and the Annual Average Emission of 5.817 Mg CO_2e ha⁻¹year⁻¹. The carbon balance, in all the years, was positive evidencing the contribution of the silvopastoral system to minimize GHG emissions and neutralize the emissions in milk production.

摘要

研究了树木成分中和的潜力，以了解牲畜、森林生产和温室气体 (GHG) 排放之间的关系。这项工作的目的是评估包括半集约化奶牛养殖在内的林牧系统中的碳平衡，并量化巴西米纳斯吉拉斯州 Vis​​conde do Rio Branco 生产的每单位牛奶的排放量。林牧系统的树木成分是半集约化生产系统中的大桉x尾叶桉的杂交种，包括Brachiaria decumbes作为牧草和杂交奶牛。碳储量是根据估计的木材量与森林清单数据、木材密度和树种的木材碳含量因子计算得出的。牲畜（肠道发酵和动物废物管理）、电力、燃料消耗、氮和石灰石施肥是使用排放因子考虑的温室气体排放。碳平衡是通过将每年温室气体排放量与该元素的增加进行比较来获得的。平均年碳增量 (IMAC) 为 7.631 Mg CO _2e ha ^-1年^-1，年平均排放量为 5.817 Mg CO _2e ha ^-1年^-1. 多年来，碳平衡是积极的，证明了林牧系统对尽量减少温室气体排放和中和牛奶生产排放的贡献。