Post-agrogenic dynamics of soil properties of eroded agrochernozems in the forest-steppe zone of Western Siberia

Abstract

Results of the study of a chronological series of post-agrogenic chernozems of slope lands of the forest-steppe zone of Western Siberia, characterised by a high degree of vertical and horizontal relief dissection, are presented. It was found that the rate of post-agrogenic transformation of abandoned soils depends on their regenerative features, the nature of the successional change of vegetation and the intensity of development of erosional processes. In the phytocenoses of young abandoned lands, 467.3 g/m2 of green phytomass and 114.9 g/m2 of aboveground mortmass are formed; in middle-aged fallows, the reserve of green phytomass is 511.2 g/m2 and aboveground mortmass is 632.7 g/m2. Total soil organic carbon accumulation in fallow soils occurs due to the formation of coarse (detrital) organic matter. No significant changes in particle size distribution as a result of the shift of arable soils to the fallow state were revealed. Bulk density was closely dependent on the structural organisation of the solid phase of soils, in which the content of macroaggregates, determining the ratio of volumes of aggregate and inter-aggregate porosity, water-holding capacity and water permeability of soils, increased. As a result of structural and functional changes in fertility indicators at the stages of young and middle-aged deposits, a high degree of recoverability was found for the content of labile humus, bulk density and aggregate composition.