Amendment-assisted myco-phytostabilization potential of plants on copper tailings in a pot-scale experiment

Mining activities have as a secondary result the production of residues stored in tailings dumps and ponds which lead to the serious environmental hazards over time. For this reason, it is necessary to install and accelerate the ecological succession on the tailings ponds, their phytostabilization being an ongoing challenge. The aim of this study was to apply an eco-technology already successfully demonstrated on two tailing dams, on a third one with a specific geochemical structure, knowing that each polluted area is a unique entity. A pot-scale experiment was carried out in a growth chamber amending the mining substrate with top soil and green fertilizers, inoculating it with 1% and 2% fungi, and sowing it with Agrostis capillaris alone, or mixed with Melilotus albus . The experimental design consisted of 14 treatments, each with 5 replicates. For the treatment with 2% fungi and sown with a mixture of two plant species, plant biomasses, technosoil respiration, total Kjeldahl nitrogen content and assimilatory pigments recorded statistically significantly higher values, compared to the other treatments. Lipid peroxidation and the content of some toxic elements in plants registered a statistically significant decrease for the same treatment. There was no statistically significant difference in mycorrhizal colonization between 1% and 2% fungi under these particular experimental conditions. This eco-technology could be successfully applied to the surface of the new tailing dam. The novelties are the success of inoculation with both 2% and 1% fungi, which substantially reduces the costs of large-scale phytostabilization using a mixture of two plants.