Relationship between mesofauna and soil chemical parameters in a biochar-managed central amazonian yellow oxisol

The present study has aimed to assess the soil mesofauna groups' density and diversity, as well as their relationship with chemical attributes of a Yellow Oxisol being managed for fourteen years with biochar (BC) increasing doses. This study was undertaken at an Experimental Station of the National Institute for Amazonian Research, in Manaus-AM. The experimental design was in randomized blocks, with four doses of BCand four replications (blocks), totaling 16 experimental units. The largest (24) and smallest (18) number, of taxonomic groups was identified in soil with no, and with 120 Mg ha-1 BC, respectively. Groups density (181,217 individuals m-2) showed not to vary significantly between treatments. This total was represented by Acari 80.70%, Collembola 6.76% and Formicidae 4.22%. Regression analysis revealed a significant, Shannon's diversity index, decrease with increasing BC dose, added to the soil. A similar trend was observed for the Collembola density C/N ratio, which decreased as the soil Al3+ content increased. Formicidae density increased with greater, soil P availability. Therefore, changes in soil chemical properties determine the mesofauna taxonomic groups, number and density, as well as each one's association degree with the evaluated treatments, since edaphic attributes define the resources necessary for their development.