Characterization of Humic Substances from Taiga and Tundra Soils by EPR Spectroscopy

Paramagnetic activity is a fundamental property of humic substances (HSs). The agricultural use soils does not only affect the qualitative and quantitative compositions HSs, but also content free radicals (FRs) in their structure. Changes composition incoming plant residues hydrothermal conditions have an effect on soil humification rates paramagnetic properties (HAs) fulvic acids (FAs). Data influence various factors FRs HAs FAs are enough. Therefore, purpose this study was to examine degree hydromorphism HA FA samples obtained from taiga tundra soils. Studies shown that increased leads growing concentration molecular virgin exhibit lower unpaired electrons when shifting automorphic hydromorphic ones. Going south north, both tends decrease due overall reduction number polyconjugated systems HSs. comparative analysis arable revealed reduces FR structure other words it accumulation biothermodynamically stable more humified compounds horizons. This contributes stabilization SOM