The Study On The Role Of Arbuscular Mycorrhizal Fungi In Pb/Zn Tailing Reclamation

A large number of mine Tailings produced in the metal mining activities, not only taking the massive agriculture and living land, but also heavy metal mine tailings will have the profound negative effect to ecological environment of the mining area in a long-term stack. Therefore considering of reasonably using the land resource and protecting the mining area resident living conditions, urgent needs to seek a feasible way to comprehensive countermeasure to mine tailings abandoned. Plant restoration is one of the most appropriate to solve environment question of heavy metal mine tailings. Arbuscular mycorrhizal symbiosis is the oldest and most widespread type of mycorrhizal association in the nature. A great deal of research has been indicated that arbuscular mycorrhzal symbiosis play a important role in protecting plants agaist the stress( like high heavy metal , the lack of nutrients and drought and so on). This paper use Pb/Zn mine tailings collecting from Fankou lead/zinc mine tailing pond of Guangdong province as growth substrates, and series of pot experiments were conducted to reveal the potential role of arbuscular mycorrhizal fungi(AMF) in plant restoration of Pb/Zn mine tailings.The effect of the arbuscular mycorrhizal fungus on clover plants growth, nutrients and heavy metal (Pb and Zn) uptake were investigated in pot experiments. Mycorrhizal and non-mycorrhizal clover plants were grown in the Pb/Zn mine tailings amended with peat,cornstalk. The results indicated:combining amended cornstalk in tailings and inoculated AMF significantly increased dry biomass of clover plants by improving phosphorous concentration and uptake and decreasing heavy metal lead concentration of clover plants.The effects of single or mixture inoculation with arbuscular mycorrhizal fungi (AMF), Glomus mosseae and Glomus intraradices, on growth and mineral nurtrition of tall fescue growing in lead/zinc mine tailings were investigated. The results indicated that, three types of inoculation treatments significangtly restrained the growth of tall fescue, in contrast with non-inoculation treatment; inoculating AMF Glomus mosseae increased the lead contentration of tall fescue; P and Zn concentration in shoot of tall fescue plants were not significantly affected by inoculation and non-inoculation. The result show that the tall fescue has tolerance to"the compound stress"of the Pb/Zn mine tailing, directly planting fescue plants on the Pb/Zn mine tailing is feasible.Futher experiments investigated the effects of amending cornstalk and inoculating AMF on the growth of Alfalfa and tall fescue. The results indicated that amending cornstalk obviously improved the dry biomass of tall fescue, meanwhile can purified the mine tailings by enhancing the Pb emigration quantity; amending cornstalk on tailings and inoculation significantly improved the P condition of alfalfa plants, and reduced the Pb concentration of alfalfa shoots by mycorrhizal symbiosis, at last reduced the toxicity of heavy metal Pb to alfalfa plants.The effect of changing the proportion between cornstalk and tailings on mycorrhizal clover plants growth were studied in pot experiments. The result show: increasing the proportion of cornstalk, significantly promoted the growth and improved the P level of mycorrhizal clover plants, and decreased the Pb concentration of clover shoots. The result indicates that the suitable proportion of modifier not only can reduce the cost and accelerate process of Pb/Zn mine tailings vegetation restoration, but also can reduce the risk of heavy metal accumulation in the food chain to avoid the adverse effect of the toxicity of heavy metal.