Сравнительная оценка методов определения педогенного органического углерода в углесодержащих почвах

Abstract

The research considered determination of carbon reserves of soil organic substances in coal-bearing soils as an important problem of the study of technogenic landscape soils of coal deposits. Basing on the ability of soils of technogenic landscapes to perform the functions of natural undisturbed soils, the total fund of soil organic substance in such soils is said to be formed not only by humic compounds, but also by oxidized carbonaceous particles. Therefore, only developing the methods for differentiating soil organic substance performing the function of humus, and non-transformed lithogenic organic substance can solve the problem of evaluating the state of coal-bearing soils. The aim of the work is a comparative evaluation of the possibility of using traditional approaches and two those which we propose to determine the content of pedogenic organic carbon in soils of coal deposit dumps. Embryosems formed on the surface of coal and brown coal deposit dumps in Kemerovo oblast (N 53 o 39'; E 86 o 53') and Krasnoyarsk Krai (N 55 o 58'; E 90 o 23') were objects of the research. Methodically, along with traditional methods based on the content of total and organic carbon determination, we use approaches that rely on functional characteristics of soil organic substance. The first approach is based on the ability of soil organic substances to deposit nitrogen in soils. This approach involves calculation of carbon content of pedogenic organic substances using the parameters of soil nitrogen reserves and its ratio with carbon (C / N) in zonal undisturbed soils. The second approach is based on the ability of soil organic substance to form organic and mineral complexes with clay particles. At the same time, the content of pedogenic carbon is determined by the value of lithogenic potential of humus accumulation (LPHA), which depends on the number of clay particles in soils. Our research has shown that for carbon-containing soils, methods based on determination of total and organic carbon give incorrect results and cannot be used in complex ecological studies of techogenic soils and landscapes. Approbation of the proposed approaches has shown that, the definition of LPHA makes it possible to obtain reliable results for embryozems formed on a dense, stony substrate of coal deposits (See Table 2), since the accumulation of clay particles in such soils is the result of biochemical weathering and their amount is proportional to the reserves of organic substance. For embriozems formed on a loose substrate of brown coal deposit dumps, the results obtained with the help of C / N ratio and nitrogen content in the investigated soils are the most representative (See Table 2). Thus, we can conclude that, even in this approximation, the proposed approaches allow carrying out large-scale studies on evaluating the ecological state and resource potential of coal-bearing soils of technogenic landscapes. The article contains 2 Tables, 39 References.