Dynamics of mine rocks and artificial soils agrochemical characteristics under the impact of long-term reclamation

Abstract

The agrochemical characteristics of mine rocks and artificial soils of forest recultivation plot № 1 of «Pavlogradska» mine were studied. The quantitative indicators of humus, phosphorus, potassium and nitrogen content of the soil and mine rocks samples were described. Changes of agrochemical characteristics of mine rocks and artificial soils, that occur as a result of long-term reclamation and exert an impact on forests suitability and silvicultural effect, were ascertained. Variants of artificial soils, created on the experimental forest recultivation plot, have qualitative differences from natural etalon soils, disturbed soils and differences between themselves. During the creation of various soil constructions in the process of recultivation it is often not taken into account the possible distant consequences that arise in connection with the dynamic features of the climate, topography, lithology, hydrology and other indicators of technogenic landscapes. Due to the functioning of these soil constructions there are significant changes in physical properties and processes, occurring in the remediation root layer, therefore there are a number of issues related to the further evolution of these structures. In this connection a studying of properties and processes in the artificial soils and an analysis of its current state and evolution prognosis become relevant, with a glance of targeted orientation of recultivation layer constructs and characteristics of specific conditions. The aim of the research is an investigation of agrochemical characteristics of bulk soils and an assessment of its forests suitability on the forest recultivation plot of «Pavlogradska» main, with an area of 3.2 hectares, where different constructions of forest plantations are being tested since 1976 on the different versions of artificial soils. The novelty of the work lies in that the findings show the dynamics of artificial soils properties under the influence of long-term biological remediation measures. The humus state of a soil is a complex of morphological traits, common stocks, properties of organic matter and processes of its creation, transformation and migration in the soil profile. This is a fundamental property of soil because it determines the variety of fertility factors. The content of organic matter in mine rocks and artificial soils ranges from 0,15±0,02 (sand) to 6,25±0,08 % (mine rock). However despite the fact that the amount of organic matter in the mine rocks is high, it is a part of the denatured organic compounds, which are not available for free mineralization. Nitrogen is a necessary element for plant development and its soil content determines the level of soil fertility. The analysis showed that the amount of nitrogen ranges from very low in mine rocks to heightened in chernozem loams. The most important biogenic elements also include phosphorus and potassium, which are essential nutrients for plants. Phosphorus and potassium availability is ranging from low in mine rocks to very high in chernozem loams. Also a decrease of potassium and phosphorus content down the soil profile is observed in different artificial soil variants, which correlates with a decrease of plant roots quantity with depth. The most relevant area of recultivation for steppe zone is forestry, in which environmentally hazardous areas are planted with reclamation forest cultures. However, it should be taken into account that creation of artificial forests in steppe zone is a measure associated with certain difficulties, particularly on the zonal chernozem soils. Even greater difficulties encountered in anthropogenic degradation of a substrate with a deterioration of its physicochemical and agrochemical properties in industrial use of lands, which should be considered in the forest land reclamation.