Sustainability indicators in the agroforestry systems of family farmers in the district of Tomé-Açu, Pará

The aim of this article was to evaluate, using sustainability indicators, agroforestry systems (AFS) on the properties of family farmers in the district of Tomé-Açu, Pará, arising from the transition processes of different production systems. Eight AFS, three areas of secondary vegetation, and three conventional systems were evaluated. Direct observation was used to evaluate the sustainability indicators, assigning a value from 1 to 10 to each indicator (1 - undesirable; 5 - moderate and 10 - ideal). The mean value of the indicators was determined for each system under evaluation. The areas under conventional systems had the lowest value, of 0.25 for the crop-health indicators and 1.32 for soil quality, which suggests the need for proper management to prevent environmental problems in areas of pasture, cleared land and monocropped black pepper. The highest values of 4.1 for the crop-health indicators and 6.99 for soil quality, were obtained in the areas of secondary vegetation, and values of 3.0 for crop health and 6.1 for soil quality in the areas of AFS-BP, emphasising the role of secondary vegetation and agroforestry systems in recovering the productive potential of agrosystems. It can be concluded that the use of a simple technique (radar charts) together with statistical methods show that secondary vegetation, agroforestry and conventional systems differ; however, secondary vegetation and AFS are more sustainable, as they showed better results for each of the indicators under evaluation compared to the conventional systems.