Influence of the fractional composition of humus substances on the proportion of water-resistant aggregates

In this study, the influence of humus substances on soil structure of six soils (Haplic Chernozem, Mollic Fluvisol, Eutric Fluvisol, Rendzic Leptosol, Eutric Cambisol, and Haplic Luvisol) of different ecosystems (forest, meadow, urban, and agro-ecosystem)in Slovakia was compared. The influence of the fractional composition of humus substances on the proportion of the fractions of water-resistant aggregates in different ecosystems was assessed. The fractions of free humic acids and those bound with monovalent cations and mobile R2O3 (r = 0.387; P urban ecosystem > meadow ecosystem > forest ecosystem