Аннотация:The aim of the study was to investigate an effect of rainfall on formation of a subsoil horizon of readily soluble salts and gypsum in Calcic Chernozem (Loamic). Mathematical and statistical methods were used to calculate the wetted depth of the soil profile under an assumption that the soil receives on its surface a one-time rainfall with volume equal to the annual precipitation. We used data for the period from 1948 to 1980 on the average long-term wetted depth of the profile of Chernozems that formed on the territory of thenorthern part of Cis-Azov region, a vast area within the Rostov region, Russia. A comparative analysis of actual long-term and estimated wetted depths of Calcic Chernozems was performed. The calculated wetted depth was 192 cm. In reality in the considered area, up to 71% of the water received on the soil surface penetrates to the depths from 80 to 159 cm. This indicates that the horizon of readily soluble salts and gypsum located at the depth of over 220 cm is a relic. The gypsum formation cannot be associated with thelevel of the current groundwater table.