Changes in the hydrophobic-hydrophilic properties of the organic matter of the chernozems of the Kamennaya Steppe

Soil samples and physical size-density fractions isolated from them (silt particle size less than 1 µm, light fraction (LF) with a density of 2 g/cm 3 the residue) ordinary chernozem were studied in three contrasting variants experimental fields Kamennaya Steppe agrolandscape Voronezh region: mowed steppe, long-term permanent bare fallow corn – main differences which are tillage (cultivated not cultivated lands) supply/absence plant residues root secretions. The LF content changes series: “mowed steppe” > “permanent corn” fallow”, corresponds to direction total carbon soil decrease value contact angle wetting (CA) surface solid phase chernozems. determination C N revealed change qualitative quantitative composition for different land use cases. Chromatographic fractionation alkaline extractions humus substances (HS) an increase degree hydrophilicity HS while simultaneously increasing hydrophobicity soil. turned out be by 63% more hydrophilic fallow” 47% corn”. While silt differed 16 27%, respectively. original plot was 41% higher 24% In addition, intense soil, so is indicator degradation under agrogenic pressue.