Aggregate index of social–environmental sustainability to evaluate the social–environmental quality in a watershed in the Southern Amazon

•Heterogeneity of social, economic and environmental conditions of the agroecosystems was registered.•Aggregate index of social–environmental sustainability confirms that the studied micro watershed in the southern edge of Amazon is socially and environmentally degraded.•Agricultural policy is a lever for sustainable rural development. The purpose of this study was to build an aggregate index of social–environmental sustainability derived from incorporation of indicators of the quality of soil, water, and vegetation, and social organization and socioeconomic variables, in order to assess the overall social–environmental quality in a micro watershed in the Southern Amazon. From a population of 105 family production units 56 were randomly selected for evaluation of indicators of the quality of soil and water as well as for conducting interviews to evaluate the farmers’ perception of soil, water, and vegetation quality and also of socioeconomic aspects of agroecosystems. The aggregate index built from social–environmental sustainability indicators shows that the selected indicators were adequate for describing social–environmental quality and confirms the hypothesis that the studied micro-watershed in the southern edge of the Amazon is in a state of collapse, and is socially and environmentally degraded.