Soil quality in an agroforestry system in the scenario of family farming in the eastern Amazon

The establishment of conservation agro-ecosystems can play an important role in improving soil quality and can contribute to the recovery of degraded areas, especially in the scenario of deforestation in the Amazon region. Our objective was to evaluate whether an agroforestry system installed in an abandoned and degraded area improves soil quality. We compared the soil of the agroforestry system with that of a secondary forest adjacent to the experiment. The soil chemical indicators evaluated were soil pH, exchangeable calcium (Ca), exchangeable magnesium (Mg), exchangeable aluminum (Al), available phosphorus (P), exchangeable potassium (K), potential cation exchange capacity (CEC), effective cation exchange capacity (ECEC), base saturation (BS%), aluminum saturation (m%) and soil organic matter (SOM). The physical indicators were soil bulk density (BD) and total porosity (TP). The biological indicators were microbial biomass carbon (MBC), soil microbial respiration (SMR), soil organic carbon (SOC), microbial quotient (qMIC) and metabolic quotient (qCO₂). The pH, Ca, Mg, P, CEC, ECEC, SOM and BS% presented higher values in the agroforestry system, while Al, H + Al and m% presented an inverse pattern, in other words, the highest values were in the secondary forest. For the physical variables, BD was higher in the secondary forest and, consequently, TP presented higher values in the agroforestry system. The indicators of biological soil quality were not altered by the land cover. Thus, conservation systems such as agroforestry systems, when properly managed, can be considered viable alternatives for the recovery of soil quality.