Abstract <p>The paper presents systematized information on the general character of soil profiles and, in particular, on the carbonate profile of natural soils and their transformation under the human impact in plowed soils of the dry-steppe zone. The study objects included chestnut–solonetz associations in the south of the Volga Upland and the northern part of the Yergeni Upland in the Volgograd oblast on rainfed and irrigated fields. Three directions of anthropogenic transformation of the carbonate profile of soils in chestnut–solonetz associations have been noted: (1) preservation of the original eluvial-accumulative profile with effervescence with HCl from a certain depth; (2) formation of profile-effervescent soils, with effervescence starting from the day surface; and (3) formation of irregularly effervescing soils having alternating carbonate and non-carbonate horizons. Six known mechanisms of carbonate accumulation in dry-steppe arable soils have been systematized and a key has been proposed for the field diagnostics of their combinations in a soil profile based on the morphological analysis and the current soil-forming conditions. A diagram of the anthropogenic transformation of soils in chestnut solonetz associations has been compiled and the criterion formulated for assessing the human-induced transformation of the soil cover on arable land in the dry-steppe zone, namely, a proportion of the surface-effervescent soils compose more than 20–30% of the area of a field. A field verification of the criterion was carried out on arable lands differing in land use history and initial environment at the Oroshaemaya experimental station in the Volgograd oblast.</p>