Pesticides are widely used in agriculture as a pest control strategy. Despite the benefits of pesticides on crop yields, the persistence of chemical residues in soil has an unintended impact on non-targeted microorganisms. In the present study, we evaluated the potential adverse effects of a mixture of fungicides (difenoconazole, epoxiconazole, and kresoxim-methyl) on soil fungal and bacterial communities, as well as the manifestation of wheat diseases. In the fungicide-treated soil, the Shannon indices of both fungal and bacterial communities decreased, whereas the Chao1 indices did not differ compared to the control soil. Among bacterial taxa, the relative abundances of Arthrobacter and Sphingomonas increased in fungicide-treated soil due to their ability to utilize fungicides and other toxic compounds. Rhizopus and plant-beneficial Chaetomium were the dominant fungal genera, with their prevalence increasing by 2–4 times in the fungicide-treated soil. The genus Fusarium, which includes phytopathogenic species, which are notably responsible for root rot, was the most abundant taxon in each of the two conditions but its relative abundance was two times lower in fungicide-treated soils, consistent with a lower level of disease incidence in plants. The prediction of metabolic pathways revealed that the soil bacterial community had a high potential for degrading various pollutants, and the soil fungal community was in a state of recovery after the application of quinone outside inhibitor (QoI) fungicides. Fungicide-treated soil was characterized by an increase in soil microbial carbon, compared with the control soil. Collectively, the obtained results suggest that the application of difenoconazole, epoxiconazole, and kresoxim-methyl is an effective approach for pest control that does not pose a hazard for the soil ecosystem in the short term. However, it is necessary to carry out additional sampling to take into account the spatio-temporal impact of this fungicide mixture on the functional properties of the soil.

The paper purpose was to establish the effect of applying biochar obtained from various organic wastes of agriculture (cow manure, straw), woodworking (pine sawdust) and food industry (pine nut shell), which are typical of Western Siberia, on the morphometric characteristics of plants (using spring wheat (Triticum aestivum L.) as the example) and the soddy-podzolic soil properties. The assessment of biochar influence was performed by a series of vegetation experiments using climatic chambers. As a result, it was found that the introduction of all the noted biochar types into the soil layer leads to a significant (p < 0.05) increase in the morphometric characteristics of spring wheat. For example, when applying the straw biochar to the soil, it results in growing the plant height to the node by 19%, while the number of leaves increased by 8% compared to the control variant. The introduction of biochar from manure leads to the increased length of the spring wheat root by 35%. Moreover, straw and manure biochars contribute to the reduction of soil acidity (increase in pH values from 7.1 to 7.4 and 7.8, respectively). The results of the comprehensive analysis indicate that the agronomic advantages of application of biochars obtained from wheat straw and cattle manure are better compared to biochars from pine sawdust and pine nut shells, which is due to higher concentration of nutrients and substances with alkaline reaction (carbonates and oxides) in the former. The results obtained are useful from the point of view of assessing the environmental risks when applying biochar ameliorants in soils typical of the boreal bioclimatic zone. Subsequent experiments, including studies of the joint application of biochars and fertilizers to the soil, will make it possible to develop recommendations for applying the thermal conversion technology for recycling the regional organic waste into ameliorants that improve soil quality and increase its fertility.

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Pesticides are widely used in agriculture as a pest control strategy. Despite the benefits of pesticides on crop yields, the persistence of chemical residues in soil have an unintended impact on non-targeted microorganisms. In this study, we evaluated the impact of the combined fungicide (difenoconazole, epoxiconazole, and kresoxim-methyl) on fungal and bacterial communities of Phaeozem. In the fungicide-treated soil, the Shannon index of both fungal and bacterial communities was decreased, while Chao1 index did not differ compared to the control soil. Among bacterial taxa, the relative abundance of Athrobacter, Sphingomicrobium, and Sphingomonas increased in fungicide-treated soil due to their ability to utilize fungicides and other toxic compounds. Rhizopus and plant-beneficial Chaetomium were the dominant fungal genera, which increased 2-4 times in the fungicide-treated soil, while the relative abundance of Mortierella and Talaromyces decreased. Fusarium acuminatum was the most abundant phytopathogenic fungus that causes root rot disease of wheat, but applied fungicide treatment decreased their diversity in the soil 2 times, which is consistent on the observed plants.