Bringing Life Back into Former Mining Sites: A Mini-Review on Soil Remediation Using Organic Amendments

Former mining sites cause serious environmental problems worldwide as they are contaminated with hazardous levels of metals. Mined lands are characterized by a deserted landscape due to the lack of organic matter in soil. Research analyses confirmed that the structure of soil in abandoned surface mines has affected the occurrence of ecological processes and natural colonization of vegetation cannot take place. Moreover, phytoextraction of metals is possible only in soils with specific parameters. Previously conducted studies proposed the in situ supplementation with biochar, compost or agri-food wastes as a solution to the lack of organic carbon and nitrogen in areas affected by mining. Therefore, the main aim of this review is to investigate what improvements different organic amendments can bring to mining-impacted soils to support plant growth without affecting the bioavailability of metals. We concluded that contaminants are specific to the mining activity, while organic treatments cause the increase of soil pH, which influences, to the greatest extent, the bioavailability of metals.