Rieznik S. Biodiagnostics of chernozems typical of the Left-Bank Forest-Steppe of Ukraine under the different farming practices

The solve a scientific problem: the biodiagnostics of dependence of the vector of soil-forming processes on farming systems. The urgency of the research is attributed to the need to search for and develop better systems for detecting and monitoring the environment status through the lens of the population’s demand for ecologically clean food, improved management of limited soil resources, fertility preservation and restoration, and support of other basic ecosystem services of chernozems. The novelty of the scientific work: the results of the study complement the modern understanding of the peculiarities of agrogenic soil formation. For the first time, changes in the soil-forming processes of typical chernozems at the different farming systems were confirmed using indicators of biological activity. The main biodiagnostic indicators characteristic of cultivated chernozems have been determined. The study purpose and scientific and practical importance are to determine the peculiarities of the formation microbocenosis of chernozem soils under the conditions of biologization of agriculture and to justify mathematically of biodiagnostic indicators that allow revealing characteristic of soil genesis in agrocenoses at the present stage of chernozems evolution. The thesis further develops the doctrine of agrogenic soil formation and deepens the concept of dependence of the vector of soil-forming processes on farming systems. The possibility of using at least 12 bioindicators to assess the soil condition was experimentally proven; of these bioindicators, of the number of actinomycetes, dehydrogenase and catalase activity were the most informative ones. It was found that agrogenic soils differed from natural ones in the number of new elementary pedogenesis processes (EPPs). In addition, factor analysis revealed that the main diagnostic feature of the cultivated soils was the strengthened role of oxidation-reduction reactions (catalase and dehydrogenase activities as well as the actinomycete number) in soil formation. It was proven that the chernozem under OFS differed in several bioindicators from the chernozem under IFS. It was also proven that chernozems in organic farming differed in several bioindicators from chernozem in intensive farming. Discriminate function analysis demonstrated significant differences between the organic farming (compost and green manure) chernozems. Using "Chernoff faces", these differences were visualized. Discriminant analysis of chernozem biological activity indicators (where F <4.0) identifies different soils by farming system factor and reliably categorizes 66.5% of the data set with statistical significance of p <0.05. The information value of 12 biological activity indicators for detecting changes in processes of chernozem formation under different farming systems was also theoretically justified and experimentally confirmed.