Restoration of soil fertility of the southern chernozem in conditions of the reserve regime of the Orenburg State Nature Reserve

This paper presents a comparative-temporal ecological characterization of the southern chernozem under the regime of the Aituar steppe site command of the Orenburg State Nature Reserve. The degree of ecological rehabilitation of chernozems in specially protected natural areas is shown. Quantitative data are provided on the supply of soil with nitrogen, phosphorus and potassium, and the content of heavy metals in the soil. Determination of the content of heavy metals and trace elements in soil samples (according to the method of Krupsky and Aleksandrova in the modification of the Central Institute of Agrochemical Services for Agriculture) was conducted in accordance with GOST 50683–94. The determination of mobile compounds of phosphorus and potassium was carried out by the method of Machigin (GOST-26205–91), organic matter by the Tyurin method (GOST 26213–9), alkaline hydrolyzable nitrogen by Kornfield. The paper presents the results of a comparison of agrochemical and ecology-toxicological studies of southern chernozem in 1996–2016. The main morphogenetic characteristics of the soil profile of the chernozem of the southern carbonate low-humus low-mass medium loamy are given. Data of morphological, physical and agrochemical properties of soils were subjected to mathematical and statistical treatment. This allowed the authors to determine morphological parameters, qualitative and quantitative characteristics of the soil and their variation within the elementary soil areas, depending on the position in the landscape and the nature of use. The data obtained indicate a positive dynamics in the provision of soil with humus and elements of mineral nutrition of plants, as well as a significant reduction in the content of heavy metals throughout the soil profile. Thus, we can talk about the natural restoration of soil fertility in conditions of a protected regime in specially protected natural areas.