Shvarov A.P., Kubareva A.V.
WATER-RETAINING CAPACITY AND PHYSICAL PROPETRIES OF STEPPE ZONE SOILS ^{[№ 6 ' 2015]}
The physical properties and water-retaining capacity of steppe zone soils (from the Voronezh region) have been studied. There were discovered the features of the soil water retention throughout the range of humidities for cycles of drying and wetting for chernozem, solonetz and solod. The evaluation was given to the degree of manifestation of the hysteresis of water retention curve these soils in units of moisture and integrated energy of water retention. There were found that the main factor determining the degree of capillary-sorption hysteresis is dispersity. We have shown that the swelling and shrinkage processes increase hysteresis water retention curve in the capillary range. For sorption range differences of humidities with one value potential of water ranges from 0,005 g/g in E horizon solod to 0.018 g/g in the lower horizons of solonets. For capillary water range hysteresis of water retention curve varies from 0.053 g/g in BCCA chernozem's horizon to 0.102 g/g BSa horizon of solonets. Integral water retention energy is best reflects the effect of soil composition and properties on capillary-sorption hysteresis. Maximal hysteresis in integral water retention energy is observed within the range of adsorbed water and it varies from 701 J/Kg in E horizon of solods to 3 182 J/Kg in solonets horizon BNa. Hysteresys of water retention energy takes lower values in the range of pellicular moisture — from 1 J/Kg in BNa and BCa horizons of solonets to 24 J/Kg in the chernozem's AB horizon. Integral water retention energy takes it's minimum value in the range of capillary moisture and it's difference in the cycle of desiccation and hydration varies from 0.2 J/Kg in the A horizon of chernozem to 1.2 J/Kg in Bg horizon of solod.