Soil-geographic interpretation of spatial variability in the chemical and physical properties of topsoil horizons in the steppe zone

The study of spatial variability in the chemical and physical properties of topsoil horizons of southern chernozems and chestnut soils at characteristic distances of less than 150, 150–800, and 800–2000 m proved that the spatial distribution of the studied properties is different for these two soils. In the southern chernozems, the maximum variability at short (<150 m) distances was observed for the organic carbon content and pH values. The contents of clay (<0.001 mm) and physical clay (<0.01 mm) fractions and the content of total nitrogen displayed the maximum variability at distances of 150–800 m. At distances of >800 m, the distribution of all the studied properties was characterized by quasiperiodicity. In the chestnut soils, the maximum variability in the contents of the clay, physical clay, and total nitrogen was observed at short distances, whereas the variability of the organic carbon content and pH values was maximum at distances of 150–800 m. At the distances of 800–2000 m, only the variability in the clay fraction content followed a quasiperiodic pattern.