Arbuscular Mycorrhizal Fungi in the Phytostabilization of Soil Degraded by Manganese Mining

Mining and processing of manganese (Mn) minerals are activities that may result in the generation of large amounts of wastes and serious environmental impacts. Several strategies have been employed to remediate areas with high Mn concentrations, but many of them imply high investments and high risk of secondary pollution. This study aimed to evaluate the phytostabilization potential of Mimosa caesalpiniaefolia Benth. in Mn mining soil influenced by inoculation with arbuscular mycorrhizal fungi (AMF). The experimental design was completely randomized, with four treatments [not inoculated (control), inoculated with Rhizophagus clarus; inoculated with Claroideoglomus etunicatum and inoculated with Rhizophagus clarus + Claroideoglomus etunicatum (Mix)], and four replicates. Inoculation with Mix and C. etunicatum had higher efficiency in protecting plants against excess Mn, due to the greater retention of this element in the roots and lower translocation to the shoots. Inoculation with R. clarus did not influence plant development and reduction of Mn contents in the shoots. The association of the AMF Mix and C. etunicatum with the species Mimosa caesalpiniaefolia Benth. enhances Mn phytostabilization in mining soils with high concentration of this element. The use of multivariate analyses proved to be an important tool with respect to the behavior of biometric, chemical and microbiological variables in mining soil with high Mn concentration.