Changes in the probability distributions of particle size fractions in chestnut soils of the Kulunda Steppe under the effect of natural and anthropogenic factors

Abstract

The stability of soil is considered as an ability to retain its properties and structural organization within the range of natural variation. Changes in the probability distribution and statistical entropy of properties, which are considered as regular properties of open systems, were used as criteria for assessing soil stability in natural and anthropogenic processes. It was theoretically shown that the steady states of geosystems, including that of particle size composition, are characterized by minimum changes in statistical entropy. The probability distribution and statistical entropy of particle size distributions in the Kulunda Steppe chestnut soils and their changes under anthropogenic impacts were studied. Heavy deflation in the 1950s–1960s resulted in the reorganization of the probability distribution of the physical sand fraction, without significant changes in the probability distribution of physical clay; the statistical entropy of all fractions increased by 6%. The long-term plowing entailed a small shift in the probability distribution of physical clay; the statistical entropy of these fractions decreased by 12%, and that of physical sand decreased by 6%. Irrigation with low-saline water entailed a significant shift in the probability distributions of fine sand and silt; the statistical entropy changed by 50–70%. Hence, the particle size distribution showed stability during deflation and long-term use of plowland and did not show it under irrigation.