Oksana Olegovna Plotnikova

The aim of the work was to evaluate the effect of shallow–water flows on the morphometric characteristics of aggre- gates of typical Сhernozems of varying degrees of erosion. A number of model erosion experiments were carried out with capillary–moistened bulk samples of the upper 10–centimeter layer of the humus horizon of typical plowed Сhernozems of the Kursk region. The control variant is a comparable sample of chernozem from a typical site of the virgin steppe Chernozem in the Central Black Earth State Natural Biosphere Reserve named after Professor
V.V. Alekhin. Morphometric parameters of soil aggregates transported by model flows with minimum, average and maximum velocity (0,3, 0,41–0,45 and 0,54–0,58 m∙s–1, respectively) were determined. It was shown that smaller aggregates have higher form factor, roundness, and a lower edge unevenness. Larger aggregates, on the contrary, are less rounded and isometric and have higher unevenness. In erosion experiments with shallow–water flows, roundness and unevenness of the aggregate surface change inversely to each other. The change in form factor and unevenness is influenced by both the degree of soil erosion and the flow rate, and these factors mutually enhance the influence of each other. Aggregate roundness is mainly influenced by the degree of soil erosion, but its effect is enhanced by the addition of a flow rate factor. Depending on the flow rate, its effect on the morphometric parameters of aggregates varies: in the area of low speeds, a rolling effect occurs, in the area of high speeds, a destructive one. The continuation and expansion of such studies will expand the understanding of the mechanisms and patterns of formation of washed soils.