FEATURES OF RECLAMATIVE CONDITION OF AGRICULTURAL SOILS OF THE PRE-ALTAI PLAINS
The zonal features of the reclamative condition of the agricultural soils of the Pre-Altai plains are described and analyzed. The changes of the following soil physical features are shown: the amount of true water-stable micro-aggregates, density, total porosity, air holding capacity, field moisture capacity, permanent wilting point, seepage coefficient, etc. It is revealed that the reclamative condition of the agricultural soils of the Pre-Altai plains is consistent with the zonal soil formation patterns and the features of particle-size composition. The highest potential for micro-aggregation is observed in the soils of meadow steppe of the Altai foothills and low mountains, and the lowest potential in the soils of the forest-steppe zone and arid steppe, which underwent eluvial soil formation stage. The lowest water-stability of aggregates is typical of slightly-loamy soils. In the medium-loamy soils, the optimum conditions for the formation of water-stable structures are observed in the Prisalairye (the Salair Ridge area) and particularly in the meadow steppe of the Altai foothills and low mountains. In the heavily-loamy sols the optimum of aggregation is typical of the meadow steppe chernozems. With the rise of bioclimatic potential, the intensity and duration of soil formation, there is decrease in soil density and solid phase density, and the increase in total porosity, immobile moisture content and water-holding capacity. Among slightly-loamy soils, the highest rate of absorption and filtration from the surface is revealed in the soils of dry steppe. Among medium-loamy soils that is revealed in the soils of forest-outlier steppe. In general, from the soils of dry steppe to central forest-steppe soils, the absorption rate is reduced by 1.3-1.5 times. Among heavily-loamy soils, a very high absorption and filtration rate is typical of the meadow steppe chernozems. In terms of absorption rate decrease, the soil of that class may be ordered as following: meadow steppe chernozems → Prisalairye chernozems → forest-outlier steppe chernozems → central forest-steppe chernozems.