Remediation of degraded soils: effect of organic additives on soil properties and heavy metals’ bioavailability

Abstract

Abstract In a three-month experiment influence of different organic amendments (coal humate, peat-gel, biochar) in comparison with mineral ameliorants (NPK and CaCO3) on chemical and physical properties of soils at different stages of degradation has been shown. Objects of the research were abrazem and podzol soils of technogenic barrens near Monchegorsk city, Murmansk region (Russia). Festuca rubra was used as a test-culture. According to the obtained data, we can conclude that organic applicants may be suitable for remediation of soils, contaminated by heavy metals. Applicants, selected for the experiment, unequally affected the soil properties and the test-culture growth. For the most disturbed and contaminated soils – abrazems –we suggest coal humate and calcium carbonate as the most promising additives for both toxicants’ immobilization and preventing bioaccumulation. Biochar and peat-gel in the tested concentration showed a more expressed positive effect on podzol soils with a lower level of contamination. In both soils, abrazem and podzol, biochar favors to the test-culture growth more, than other amendments. The potential advantage of used organic amendments, coal humate and biochar, in contrast to ameliorants is their ability to improve the physical soil properties.