Indicadores de carbono do solo em sistemas agroflorestais com potencial de uso em processo de transição produtiva agroecológica

Abstract

Traditional production systems have proved to be unsustainable in the socioeconomic and environmental spheres. A less aggressive agriculture is an alternative for the conservation of ecosystems. The process of changing from a traditional management for an alternative one is called a productive transition. The objective of this study was to evaluate soil carbon indicators in traditional and alternative production systems in areas of agroecological productive transition. The study was conducted in family farms located in Igarapé-Açu and Tomé-Açu, municipalities of the northeast of Pará. Traditional (slash-and-burn) and alternative (cut-and-grind and AFS) systems were selected, as well as secondary and primary forests (used as a reference area). The litter stocks, carbon stocks in the soil, densimetric fraction of soil organic matter and litter were analyzed. Also, an evaluation of the potential of the carbon stock as a subsidy to estimate environmental services was made. The cut-and-grind system presented the highest litter stock and carbon stock in the litter, while the AFS did not differ from reference areas. For the carbon stock in the soil and the densimetric fraction of soil organic matter no significant differences were found between the systems and the reference areas. Alternative systems had a large capacity to store carbon. The quantification of carbon stocks (soil and litter) and the stock of litter shows potential as an indicator to subsidize the provision of environmental services, as well as certify the quality of agroecosystems.