Environmental evaluation of remediated lands quality of manganese quarry lands (Zaporizhsky and Olexandrovsky opencast workings) on humus content and salinity

Abstract

Environmental protection, rational use of natural resources and ensuring the ecological safety of human life are integral conditions of sustainable economic and social development of European Union. Mining industry is one of the powerful factors that leads to degradation of various native landscapes. Withdrawal of agricultural land from intended use results from the minerals extraction. Instead them man-made landscapes (dumps and quarries) are formed, as well as destructive territories characterized by subsidence, contamination with toxic compounds, decrease of species richness and biological diversity. Disturbed territories formed during mining process are usually partially restored with remediation. Remediation process consist of two stages: technical and biological. In the result of technical stage implementation, substrates with different potential fertility having different environmental properties and quality are formed. However, in quality assessment of remediated soils insufficient attention is paid to restoration of the soil environmental properties, namely their suitability for existence of soil biota, which ensures the soil sustainability and vitality. Purpose of the presented work was to assess quality of remediated lands in condition of Ordzhonikidzevsky manganese quarry (Olexandrovskiy and Zaporizhkiy careers) on the possibility of their use and suitability for soil biota existence, as well as providing recommendations for further rational economic use of them. Data on chemical properties of reclaimed soil were collected on the sites of performed recultivation. Humus content was determined according to DSTU 4289: 2004, analysis of water extraction was carried out according to GOST 26425-85, GOST 26426-85, GOST 26427-85, GOST 26428-85. The study is novel in that it is proposed to take into account environmental conditions for existence of soil invertebrates which play a crucial role in formation of agro-system stability mechanisms. The main indicators determining the productivity of remediated lands and the degree of their suitability for soil biota existence are values of actual acidity and salinity degree. An assessment of the reclaimed lands quality on the Ordzhonikidzevsky ore mining and processing enterprise was carried out on the example of Zaporizhsky and Olexandrovsky open-cast workings on the possibility of their economic use and suitability for the soil biota existence, as well as recommendations for further rational use. It was found that studied areas by the main characteristics are suitable for the further settlement and successful existence of soil biota. It is concluded that as a result of the technical stage of reclamation, an artificial reclaimed soil was obtained, which, according to the main characteristics, is similar to native zonal soils located in this area prior to mining; the recultivated soil has somewhat less fertility and greater salinity of lower horizons, but it is able to perform ecological functions and can not only be used for economic purposes, but also perform ecological role, serving as an environment for existence of soil invertebrates.