The aim of this research is to investigate the present status of ordinary chernozem in Specially Protected Natural Areas (SPNA) of the Lower Don. The objects of the study were ordinary chernozems carbonate medium deep and deep on loess loam of SPNA of the Lower Don: Botanic Garden of the South Federal University (SFU), Persianovskaya Reserve Steppe, protected fallow land “Priazovskaya Steppe” of study-experimental farm of SFU “Nedvigovka”. In was revealed that the different content of humus, as well as the terms of texture and elemental composition of soils, depends on the period and regime of protection of SPNA. Comparing the data on humus status of considering soils over the years of the study enables to find that from 1953 to 2014 humus content decreased from 4.42 to 3.55 % in ordinary chernozem of Botanic Garden of SFU. In chernozems of Nedvigovka and Persianovskaya Reserve Steppe, as opposed to chernozem of Botanic Garden, humus content was stable from 1953. Depending on humus content and its reserves, depth of humus-accumulative horizon A and humus horizon A+B, the level of availability of macro- and micro-elements, ordinary chernozems of the study SPNA can be ranked as following: Persianovskaya Reserve Steppe > Botanic Garden of SFU > Persianovskaya Reserve Steppe. This rank is corresponding to the duration of protected regime. Botanic Garden of SFU situated in the center of megalopolis (the city of Rostov-on-Don) has higher content of lead (Pb) in the topsoil of ordinary chernozem comparing to the other soils of considering sites.
Keywords: soil texture, humus, Specially Protected Natural Areas, heavy metals, chernozems.
