The Impact of Agricultural Activities on the Substitution of Chemical Elements in the Black Soils of the North Caucasus Federal District

In order to justify the reasons for the decrease in the fertility of chernozems of the North Caucasus Federal District in long-term stationary experiments (from 12–20 years of using arable land), the authors, on typical chernozem and ordinary chernozem of the warm southern facies, studied the direction of change in the concentration of typomorphic chemical elements in connection with the duration of exposure of crop rotation and permanent crops. We analyzed soil samples taken from full-profile soil sections. The content of the elements was determined by flame photometric and atomic absorption spectrophotometry. The research results confirm the destructive effect of prolonged exposure on the soil of anthropogenic factors on the series of chemical elements. The results also indicate the importance of timely detection of areas of chernozems with a violation of chemical composition. For the first time, based on the analysis of long-term data, we indicated the orientation and conditions of migration of mobile elements that determine the productive power of the chernozems of Ciscaucasia. The decisive influence of the type of crop rotation on the content and ratio of chemical elements in comparison with the fractional composition of chernozems is proved. It is proposed to compensate for the negative effect in intensive crop rotation on typical chernozem, to plow straw, stalks, tops of agricultural crops, and to introduce organic fertilizers. Monitoring and timely recording of soil changes in agro-ecologically similar territories will optimize the timing of observations of changes in the parameters of chernozems and reduce the volume and cost of resources, as well as the cost of work. The frequency and priority of determining elements in the 12–20-year range in similar agroecological territories with a disturbed ratio of elements, identifying leaders and their satellites, series of substitution, their mutual influence within the system are presented for the first time.