Effect of humic substances and clay minerals on the hydrosorption capacity of clay particles in meadow soils (Middle Priamurje, Far East of Russia)

摘要

Background The study of clay fractions is usually focused on water-dispersible clay (WDC), which is a good indicator of many soil processes involving water (water erosion, transfer and removal of nutrients and contaminants). Aggregated clay (AC) that remains after WDC extraction is also important, as it controls the formation of aggregates and their mechanical and water resistance. The aim of this study was a gradual extraction of WDC and AC fractions from periodically overmoistening meadow podbel (mollic planosol) and the study of the content and composition of humic substances and clay minerals in these fractions as well as their effect on the hydrosorption capacity.