Impact of Viticultural Management on Greenhouse Gas Dynamics: A Comparative Study of Table Grape Cultivation and Native Vegetation in Semi-Arid Brazil

The Lower-Middle São Francisco Valley is Brazil's primary export hub for premium table grapes. As global markets increasingly demand low-carbon products, quantifying greenhouse gas (GHG) emissions is vital for enhancing market value and developing mitigation strategies. This study measured soil CO₂, CH₄, and N₂O fluxes in two commercial vineyards (cvs. BRS Vitória and Arra-15) compared to preserved native vegetation (Caatinga) from August 2023 to January 2024.
Using static chambers and gas chromatography, results showed average CO₂ fluxes of 9.48 mg C-CO₂ m^-2 h^-1 in the Caatinga, significantly lower than in BRS Vitória (50.5 mg C-CO₂ m^-2 h^-1) and Arra-15 (37.4 mg C-CO₂ m^-2 h^-1). CH₄ fluxes were low and positive in cultivated areas (3.23 and 5.07 ug C-CH₄ m^-2 h^-1), while the Caatinga soil acted as a net sink due to its aerobic conditions, showing slight emissions only after January rainfall. N₂O fluxes were negative in native vegetation (-7.64 ug N-N₂O m^-2 h^-1) and positive in the BRS Vitória (6.28 ug N-N₂O m^-2 h^-1) and Arra-15 (9.72 ug N-N₂O m^-2 h^-1) fields. Despite the agricultural input, these N₂O emissions remain low compared to other crops. This efficiency is attributed to split-fertilization via fertigation, which optimizes nitrogen availability and minimizes atmospheric losses. These findings highlight that precision management in semi-arid viticulture can effectively limit the carbon footprint of high-value fruit production.