Respostas morfofisiológicas de Sabiá (Mimosa Caesalpiniaefolia Benth.) associado a Micorrizas Arbusculares e Rizóbios em solo de mineração de manganês

Abstract

The excess of manganese in the soil promotes morphophysiological disturbances in plant species, compromising the establishment and consequently the rehabilitation of areas degraded by the exploitation of this ore, requiring human intervention. Thus, the objective of this work was to evaluate the morphophysiological changes related to the tolerance or sensitivity of thrush (Mimosa caesalpiniaefolia Benth.) Inoculated with arbuscular mycorrhizal fungi and rhizobia in soils degraded by Mn mining. The study was carried out in a greenhouse, adopting a completely randomized design, with plots subdivided over time, considering: i) plots with five treatments (control “without inoculation”, rhizobia, mycorrhiza and mix (mycorrhiza + rhizobia)); ii) subplots constituted the evaluation periods. The physiological variables photosynthesis, stomatal conductance, internal CO2 concentration, transpiration and ratio between internal and external CO2 concentration (Ci / Ca) in four periods and the SPAD index (Soil Plant Analysis Development) in seven periods were evaluated. In addition, the morphological variables plant height and stem diameter were evaluated in eight seasons throughout the development of the plants. At the end of the experiment, the root dry matter (MMSR) and aerial part (MMSPA) mass, leaf area (AF), nodule dry matter number and mass, colonization and spore abundance were analyzed, in addition to manganese levels (Mn), phosphorus (P), soil pH and total accumulation of macro and micronutrients (N, P, K, Ca, Mg, Mn, Cu, Zn and Fe) in the aerial part of the plants. The double inoculation (Rhizobia + Mycorrhizae) promoted physiological changes in plants, stimulated the growth and incorporation of biomass, which can be explained by the greater supply of nutrients by the associations, in addition to strategies of these microorganisms to decrease phytotoxicity favoring tolerance and quality of seedlings. The double inoculation (mycorrhiza + rhizobia) favors tolerance and the establishment of thrush (Mimosa caesalpiniaefolia Benth.) In soils in areas degraded by manganese mining.