Biocarvão e fungos micorrízicos arbusculares no desenvolvimento de Phaseolus vulgaris L. cultivado em solo contaminado com cobre

Abstract

The presence of excess copper in the soil can be toxic to plants and other organisms. In this case, alternatives for remediation of areas contaminated by the metal are being sought, in which biochar can act as a copper adsorbent in the soil, as well as arbuscular mycorrhizal fungi (AMFs) forming a symbiotic association with plants and having the potential for phytostabilization of this metal in the roots. Thus, three scientific studies were developed to elucidate the hypotheses that biochar reduces copper availability and promotes the development of common bean in contaminated soil and the symbiotic association with mycorrhizae results in less metal translocation and reduced toxicity to plants. Therefore, the first research aimed to verify the effects of adding biochar in soil contaminated with copper and the development of common bean; the second study aimed to evaluate the use of AMFs for the development and accumulation of copper in Phaseolus vulgaris L. plants cultivated in soil contaminated with copper and; the third aimed to determine the effect of applying biochar combined with the use of arbuscular mycorrhizal fungi in the cultivation of Phaseolus vulgaris L. in soil contaminated with copper. The results showed that biochar had a positive effect on the reduction of copper availability in contaminated soil, in addition to the decrease in the metal content in the plant tissue of P. vulgaris L. As well as the percentage of seed germination, overall plant development and productivity were higher even in soil contaminated with copper. Inoculation with the isolates Rizoglomus clarum and Scutellospora pellucida promoted an increase in the development and production of beans grown in soil contaminated with copper and also reduced the availability of the metal. The species S. pellucida provides less translocation of the metal to the aerial part of the plants. The combined use of biochar and arbuscular mycorrhizal fungi results in an increase in height, percentage of seed germination, aerial and root dry mass and grain yield of common bean plants grown in contaminated soil, while the available copper content in the soil, in the root, in the aerial part and in the bean grain it is smaller. Copper translocation to the aerial part of P. vulgaris was also lower with the combined use of biochar and AMFs.