Litter Stock and Soil Microbial Activity in Agroforestry Systems

This study aimed to evaluate the effect of two agroforestry management systems (AFS 1 and 2) on the stocks of litter, soil chemical properties, soil activity, and soil microbial biomass (SMB), comparing them to an annual agriculture area (AnAg) and a secondary forest area in the municipality of Paraty, State of Rio de Janeiro. The pruning management of the AFSs has promoted increased levels and/or stocks of nitrogen, phosphorus, potassium and magnesium in the litter, taking the systems to the condition of similarity when compared to the secondary forest and superiority in relation to the stock observed in the AnAg area. The carbon content from the SMB and the soil basal respiration did not vary between the AFS and the AnAg area throughout the year. In contrast, the forest area presented the highest values of these variables combined with the total organic carbon content in the summer. AFS-2 showed high microbial quotient in the winter, presenting higher sensitivity of microorganisms to changes in vegetation cover than in soil chemical properties.