The properties of chernozems (Rostov region) located on abandoned lands of different ages in comparison with their arable analogues have been studied. The main attention is paid to the carbonate status of the studied chernozems. Data on the morphology of soil profiles obtained during the field survey, meso- and micromorphological descriptions, and the physicochemical properties of the soils were analyzed. Radiocarbon dating of carbonates in the carbonate-accumulative and transitional to the parent material horizons has been performed. Decompaction of the former plow and lower horizons to a depth of 50 cm is clearly manifested in the abandoned soils. Accumulation of organic carbon, partial leaching of carbonates, and a decrease in pH take place in them. The hard carbonate pedofeatures in the lower part of the profile are subjected to dissolution and gradually disappear. At the same time, migrational forms of carbonates appear in the upper part of the profile. In chernozems abandoned from cultivation for 30 years and more, their carbonates acquire a new quasi-stable state differing from that in the arable soil. The vegetation that settles on abandoned land has a significant effect on the transformation of the soil carbonate status.