Destruction of soil aggregates in slope flows

Abstract

Field studies and model experiments, as well as theoretical considerations, suggest that bed sediments represented by soil aggregates in overland flows on slopes exert a considerable influence on the intensity of erosion processes. In this context, one of the key problems in the development of adequate erosion models is the problem of the rate of destruction of such aggregates in the flows. The results of experimental studies of the destruction of aggregates of chernozemic soils are analyzed. It is found that the destruction of soil aggregates in the flow proceeds in two stages. During the first stage, the aggregates are rapidly broken apart into smaller fragments. During the second stage, these fragments are subjected to abrasion. An equation describing the destruction of aggregates upon their movement in the flow in dependence on the aggregate size and the distance of aggregate transport is suggested. The effect of some groups of soil microorganisms on the aggregate resistance to the destruction is shown.