MOLECULAR-MASS DISTRIBUTION OF HUMIN SUBSTANCES OF SOILS OF WESTERN TRANSBAIKALIA // BSU bulletin. Biology, geography. - 2017. №3. . - С. 55-58.

MOLECULAR-MASS DISTRIBUTION OF HUMIN SUBSTANCES OF SOILS OF WESTERN TRANSBAIKALIA

UDK: 631.417.2

In meadow-chernozem permafrost and chestnut soils of Transbaikalia, differences in the structure of humic substances were found using the gel chromatography method. It was found that humic acids include fractions with molecular weights: ≥100, 50–70, and 5–15 kDa, respectively, whereas fulvic acids — one fraction (1.5-4.4 kDa). This ratio of frac- tions in the structure of humic substances of soils of different origin determines the nature of the entry of organic matter into the soil and local conditions in the zone of humus for- mation. In oxidizing conditions the processes of chemical and microbiological mineraliza- tion prevail; in anaerobic, — along with a slowed-down mineralization of organic matter, its conservation and, possibly, a relative accumulation of microbiologically resistant com- ponents to further transformation take place.

chestnut soils, permafrost-affected meadow-chernozemic soils, humic substanc- es, humic acids, fulvic acids, molecular weight distribution.