Biogenic properties of soil cover during coal mining (a case study of the Azeiskii deposit)

A study was made of the biogenic properties of soil cover of disturbed lands in the settings of Eastern Siberia from the spatio-temporal perspective. The objective of detailed investigations was to examine the soils and grounds of the temporarily closed-down area of the Azeiskii coal deposit. The focus of the research was on annual observations of the status of soil cover, its transformation and on the measures for reduction in the negative influence on the environment. It is established that the acid-alkaline conditions vary from weakly acidic to weakly alkaline. The soils and grounds are characterized as low-enriched with nitrogen (from 0.01 to 0.58%) and humus (from 0.1 to 0.33%). Biological activity of soils and grounds is comparable with benchmark soils and refers to moderate activity, and their transformation across time occurs according to the progressive type. An assessment of the degree of biotoxicity by biotesting with seed of higher plants showed that the soils and grounds do not exhibit any inhibiting properties; however, the biomass of the germinated seeds is inferior to the benchmark soil. The main groups of microorganisms are sufficiently saturated both quantitatively and qualitatively but to a considerably lesser extent that are in the benchmark soil. There is a diversity of bacteria and microscopic fungi characteristic for soddy podzolic soils of Eastern Siberia which are tolerant to neutral and weakly alkaline soils. Interpretation of the results from investigating the biogenic properties of soils and grounds indicates that they can be characterized as satisfactory and be categorized as embryozems.