Emissões de gases de efeito estufa (GEE) na Bovinocultura Leiteira: avaliação em uma Propriedade Rural de Senador Cortes – MG

Abstract

Family farming plays a crucial role in the food supply and the Brazilian rural economy. In the context of greenhouse gas (GHG) emissions, agriculture and livestock farming are significant, generating emissions through processes such as enteric fermentation in ruminants, animal manure management, flooded rice cultivation, burning of agricultural residues, and the use of nitrogen fertilizers. These emissions are fundamental for GHG reduction strategies in family farming, contributing to climate adaptations that address manure management and livestock farming. This study aims to estimate GHG emissions, such as methane (CH4) and nitrous oxide (N2O), on a dairy cattle farm in Senador Cortes, MG, including the characterization of livestock activities, focusing on enteric fermentation and CH4 and N2O emissions from manure management, comparison of emissions with data from Minas Gerais and Brazil, identification of the main emission source on the farm, and suggestions of sustainable practices for dairy cattle farming. The methodology adopted integrates IPCC guidelines and EMBRAPA methods for analyzing emissions. Results indicate that dairy cows on pasture are the largest emitters, followed by confined lactating females. Confined young cattle, due to their rapid growth, have a higher emission factor compared to those raised on pasture. Confined dairy cattle and pastureraised young cattle together account for 65% of total methane emissions on the farm, while pasture-raised cattle are responsible for 55% of emissions of this gas. N2O emissions from confined lactating adults and pasture-raised young cattle were 73.18 and 44.43 kg N2O/year, respectively. Manure management contributes significantly to indirect N2O emissions, being four times higher in confined adults compared to those on pasture, and three times higher among pasture-raised young cattle compared to those on pasture. Cattle in confinement are responsible for 52% of total emissions of N2O leached on the farm. Compared to previous EMBRAPA inventories, estimates for enteric fermentation and nitrous oxide diverge significantly, highlighting the need to prioritize adaptations and mitigation in manure management. This study highlights the importance of sustainable practices in livestock farming to reduce GHG emissions, adapting to the realities of small Brazilian rural properties.