First approximation of soil quality critical limits in land use systems in the Brazilian Amazon

[Display omitted] •Land use systems influence soil quality in the Brazilian Amazon.•Agroforestry Systems show higher soil quality indices than Pasture System.•The SQI from linear scoring and MDS is recommended for soil depth of 0–20 cm.•Clay content and K-factor allow establishing critical limits of soil quality. Soil quality study as an assessment tool can contribute to soil management and guide land use decisions. We developed and evaluated soil quality indices (SQI) for land use systems in the Brazilian Amazon and identified the critical limits of soil quality as a first approximation. Additionally, we proposed an equation to determine Denardin’s Erodibility factor by a simpler and accessible method. We performed 21 physical, chemical, and biological analyses of 225 soil samples (0–20 cm depth) from five land use systems (LUS). We integrated and compared 12 SQIs using two data sets (total and minimum), two scoring methods (linear and non-linear), and three SQI integration approaches (Additive, Weighted additive, and Nemoro). The results indicate that in all LUSs, the most significant and best-estimated integration of soil indicators was the Additive SQI using the minimum data set and linear scoring method. Only clay content and Denardin’s Erodibility factor from the minimum data set showed significant linear regressions and high coefficients of determination (r2 > 0.50, P