Pegada de carbono do caju em diferentes sistemas de cultivo: métodos de quantificação de gases de efeito estufa e projeções

Abstract

In the face of the climate crisis, food supply chains are increasingly seeking to implement sustainable production practices; for example, studies focused on the fruit sector. Cashew farming plays an important socioeconomic role in agriculture in Brazil, especially in the Northeast region. Thus, the objective was to evaluate, compare, and integrate methodological approaches for estimating the carbon footprint in Brazilian cashew farming, considering both life cycle inventories based on empirical equations and the dynamics of carbon in biomass and soil throughout the useful life of the orchards. Initially, different methods for quantifying GHGs in a conventional cashew production system were evaluated. The Nemecek-Calc, WFLDB, IPCC-Calc, BR-Calc, and Agri-footprint methodologies were compared according to ISO 14067 standard. The results showed variations of up to 24.5% between the methods, with N₂O being the main contributor to emissions. Based on criteria of methodological clarity, scientific robustness, and suitability to regional data, the WFLDB, IPCC-Calc, and BR-Calc methods showed the best performance. In a second stage, the carbon footprint was integrated with the quantification of carbon stored in biomass and the modeling of soil organic carbon (SOC) throughout the cashew tree's production cycle, considering a lifespan of 25 years. Five production systems were evaluated in experimental and commercial areas, including monoculture and intercropping systems. Biomass was quantified using specific allometric equations, and the SOC (0–20 cm) was estimated using the RothC model. The results demonstrated greater carbon accumulation in biomass and soil in diversified systems, reflecting lower carbon footprint values compared to conventional systems. It is concluded that the methodological choice and management system significantly influence the carbon footprint results in cashew farming, highlighting the potential of diversified production systems as a strategy for mitigating climate change and supporting the sustainability of the sector.