Soil Biogeochemical Features of Nadym-Purovskiy Province (Western Siberia), Russia

An elemental composition of soils has been studied on the example of northernmost merge of taiga zone in Westerns Siberia, namely in Naym-Purovskiy district. The trace elements (As, Cd, Cu, Mn, Ni, Pb, Zn) content has been determined with the use of atomic absorption spectrometry method. Chemical soil composition was determined with the use of X-ray fluorescence analyzer. It was shown that the silica content in studied soils were about 69-74%, which indicated the long cryogenic transformation and related weathering alteration. The indexes of soil fertility were low due to percentages of nitrogen, which is in maximum is about 0.02 %. The pyrogenic podzols are considered as most fertile, while the C/N ratios here are minimal and the pH indexes are highest. The content of all studied trace elements were low in sampled soils. An average clark values were fixes as following Zn - 0.73; Cu, Mn - 0.32; Ni -0.31; Pb 0.24; Cd and for As was lower than 0.1. The studied province are characterized by extremely low content of elements even if one compare with low background concentration, which is typical for West- Siberian geochemical province. The Cu and Mn concentrations are comparable with the lowest level, described by V.V. Kovalskiy or lower. The biological accumulation of the elements is expressed in low rates in soils of both taxonomy trenches: organogenic and postlithogenic ones (namely in the superficial horizons). Cd is fixed been accumulated in the topsoils of peat eutrophic soils (Dystric Hystosols). Pb was dominated in Histic Gleysols. Other elements did not showany trends of biological accumulation. There is evident eluvial-illuvial profile distribution of iron in Podzols. The differences in elemental composition of organogenic and mineral horizons are low due to penetration of the fine earth into superficial soil horizons.