Soil Reclamation of Copper Tailing with Organic Waste Stimulate Long Term Vegetation Recover in Central Chile.

Organic waste application to reclaim surface of mine tailings is an effective solution for stabilizing and managing post operative mine tailings. The revegetation alternative controls surface erosion, mitigating environmental contamination and reducing substrate metal bioavailability. The vegetation cover required special physical and chemical conditions, which can be developed after applying organic waste as substrate enhancers. Tailings conditioning is necessary because they have extremely hard conditions for plant growth and development. These harsh conditions include low nutrients concentration, high salinity and metals concentrations, and very poor organic matter content.   The main objective of this study was to evaluate the long term efficacy of incorporating different types of organic wastes for the quality of the site and the substrate conditions in the mine phytostabilized tailings. A field trial was conducted on a mine copper tailing located in Ovalle, a semi-arid Mediterranean area in north-central Chile. Two doses of waste water treatment biosolids, olive oil wastes and pisco wastes were applied at each study plot in 2008. Field measurements demonstrated that application of organic residues significantly improved the physicochemical parameters that limited the establishment and growth of the vegetation cover and low application doses were enough for high plant covers six years following application. In addition, vegetation cover was directly and positively correlated to macroaggregates in the substrate. We can conclude assisted phytostabilization of mine tailings is likely a technically effective solution for the valorization of organic residues.