编号 10 (2024)

The processes of mineralization of xenobiotic organic compounds and their inclusion in the biogeochemical cycle, which is carried out due to their biochemical (microbiological) transformations, are considered. The state of pesticides in the soil and their degradation potential are assessed. The features of microbiological transformation and degradation of pesticides in soils, natural waters and bottom sediments are shown. The physicochemical and biological properties of agroecosystems affecting the transformation of organochlorine pesticides are characterized. A historical digression into the problem of microbial transformation of pesticides is given and the current state of knowledge of this problem is presented.

A comparative analysis of the physical properties of meadow soils in agroforestry landscapes of the Central Chernozem region over a long period of time was carried out. The study was carried out on the soils of a seasonally waterlogged complex. According to the 2004 classification, these soils belong to hydrometamorphosed agrochernozems and humus-hydrometamorphic saline soils. The granulometric composition of the soils depended on the nature of soil moisture. In automorphic chernozems, a decrease in the proportion of the silty fraction of humus horizons was noted. Hydromorphic soils were characterized by an increased content of silt. Its role in carbonate horizons increased significantly. In the structural and aggregate state, an increase in the proportion of the lumpy fraction was noted in years with precipitation exceeding the long-term average. As part of the agronomically valuable aggregates, 5–10 mm aggregates were the dominant fraction. The share of small dusty aggregates accounted for an insignificant part. The use of chemical meliorants on meadow soils improved the structural condition of meadow soils. An increase in the structural coefficient was noted. All studied soil differences were characterized by high water resistance of structural separations.

The effectiveness of agro-reclamation techniques for preserving the fertility of chernozem soils of fruit plantations under conditions of irrigation with mineralized waters in the conditions of the steppe zone of fruit growing in the Krasnodar Territory in irrigated intensive plantations of apple varieties of winter ripening on a low-growing rootstock M9 was studied. The effect of the use of chemical meliorants (phosphogypsum), soil mulching, application of water-soluble organo-mineral fertilizers through a drip irrigation system and a combination of these agricultural techniques on the basic agrochemical and physico-chemical properties of ordinary chernozem was studied. In fruit plantations, with drip irrigation with mineralized waters, the use of a complex of agro-reclamation techniques contributed to the normalization of the reaction of the soil environment, a decrease in the accumulation of water-soluble sodium salts in the root layer of ordinary chernozem by 39.7%, a decrease in the content of exchangeable sodium in the zone of local soil moisture by 33–34%, an increase in the content of mobile phosphorus in the soil under droppers by 18.9% compared with traditional zonal cultivation technology.

To assess the prospects for the joint use of entomopathogenic fungi (EPF) and entomophages in plant protection from greenhouse whitefly, the influence of volatile organic compounds (VOCs) of fungi on the behavior of the phytophage and its parasitoid encarsia in 2 types of olfactometers was studied. In the Y-shaped olfactometer, it was revealed that 3 out of 9 EPF strains had a significant effect on the behavior of the imago phytophagus. The mycelium of the Vl 72 strain of the L. muscarium species showed an attractive effect (AE = +16), and for the Vl 61 strain of the same species and the Vit 71 strain of the L. attenuatum has been found to have a repellent effect against the pest (AE = –28 and –20, respectively). Experiments in two-chamber olfactometers, where T. vaporariorum was tested not individually, but in groups (15 individuals each), showed that all the studied strains did not affect the reactions of the phytophage. The activity of VOCs fungi against encarsia was less pronounced compared to whitefly. In the Y-shaped olfactometer, it was shown that only Vit 71 (L. attenuatum) showed an attractive effect, the remaining strains did not cause reactions in the parasitoid or showed a tendency to attract it.

The possibility of an earlier and more accurate prediction of protein accumulation in grains of different varieties of spring barley of steppe and Western European ecotypes was investigated. The experiments were conducted in the central part of the Voronezh region in the Research Institute of the Central Research Center “Kamennaya Steppe” in 2019–2021. Basically, a positive and high correlation was found between the nitrogen content in the soil and the elements of productivity, which allowed us to judge the importance of mineral nutrition for the formation of grain productivity of barley. In crops of barley varieties without the use of fertilizers in all phases of plant development, the production process, depending on the nitrogen content in the soil, was more intense than in variants with the use of fertilizers. With the use of fertilizers, the intensity of the production process decreased by 5.5% during tillering and by 25.0% during the earing phase. A fairly close positive correlation was noted between the indicators of stem length (r = 0.66–0.68), productive stem (r = 0.52–0.59) and yield (r = 0.78–0.79) with nitrogen content in the soil from the tillering phase to milk ripeness in both non-fertilized and fertilized variants. A positive correlation of nitrogen content in leaves with a mass of 1000 grains was revealed: r = 0.60, 0.50–0.70, respectively, in the experimental variants. In 2021, provided with moisture, the nitrogen content in the leaves in the fertilized version was 30.8% in steppe samples and 11.8% in western samples compared with the control. The efficiency of fertilizers in the conditions of arid 2019 was reduced to 7.1–8.1%. On average over the years, when analyzing the indicators of leaf diagnostics, the effectiveness of fertilizer application in steppe varieties was 20.3, 21.1 and 8.9% in the phases of tillering, earing, and milk ripeness, while in Western varieties it was significantly less – 10.4, 11.4 and 6.1%. The maximum effect of the use of fertilizers for the grain mass index per 1 m² was obtained in the dry 2019: 27.0 and 34.7%, respectively, depending on the group of varieties (steppe and western). The indicators of protein content in grain and its vitreousness of steppe varieties significantly exceeded the indicators of Western varieties by years and variants of the experiment. It has been shown that the use of mineral fertilizers at a dose of N60P60K60 when sowing in arid conditions was effective for barley cultivation. This technique increased the yield and weight of 1000 grains due to the high accumulation of nitrogen in the leaves by the end of the growing season, which further contributed to an increased accumulation of protein in the grain and its vitreousness, especially in varieties of steppe origin.

The reactions of the antioxidant system (AOS) of daily germinating seeds and 8-day-old pea seedlings cultivated using 10% and 100% aqueous extract from spent oyster mushroom straw substrate (hereinafter extract) were studied. The mother liquor was taken for 100% extract after its preparation, and the 10% was obtained by diluting the mother liquor. The plants were grown in oligotrophic hydroponic conditions and in eutrophic conditions on gray forest soil. The activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), expression of SOD-1, CAT-1, POD genes, and the content of low molecular weight antioxidants (NMAO): ascorbate, phylloquinones, and free proline were studied as the main indicators of the AOS reaction. The inhibitory effect of 10% and 100% extract on the activity of SOD and CAT, but not on the activity of POD in daily germinating seeds, has been shown. At the same time, the content of mRNA transcripts of the SOD-1 and POD genes decreased only slightly in seeds cultivated with 100% extract, in the remaining experimental groups the level of gene expression did not differ from the control. The content of ascorbate in all experimental groups did not differ from the control, and phylloquinones and free proline were less than in the control. In the leaves of 8-day-old seedlings cultivated in a hydroponic medium, in all experimental groups, the activity of AOS enzymes, the expression of their coding genes and the content of phylloquinones and free proline did not differ from the control. At the same time, the ascorbate content was higher. In plants cultivated in soil using a 10% extract, all EPA indicators did not differ from the control. In plants grown using 100% extract, the activity of SOD, the expression level of the SOD-1 gene, the content of ascorbate and free proline were higher, and the remaining indicators did not differ from the control. Thus, the extract at the initial stages of germination inhibited the AOS of peas, followed by restoration (in oligotrophic conditions) and enhancement (in eutrophic cultivation conditions) of its work.

In the vegetation experiment, with the introduction of Cd²⁺ into sod-podzolic soil at concentrations of 25 and 50 mg/kg, barley of 4 varieties was grown, which, according to the results of a laboratory experiment with seedlings, turned out to be contrasting in resistance to the action of Cd²⁺. The aim of the work is to find out whether these varieties retain their properties as resistant or sensitive to cadmium not only as a seedling model, but also during the entire plant ontogenesis. The appearance of plants, plant height, biomass, leaf area, enzyme activity associated with plant protection from environmental stress factors, phytohormone content in aboveground biomass, grain weight, straw and 1000 grains, cadmium accumulation in aboveground plant biomass (straw and grain) were evaluated. Significant differences between groups of cadmium-resistant and cadmium-sensitive varieties were revealed in the experimental conditions. In terms of morphometric parameters and productivity when grown on cadmium-contaminated soil, resistant varieties significantly outperformed sensitive ones. These effects were most noticeable at a cadmium dose of 50 mg/kg, and a dose of 25 mg/kg was insufficient for confident differentiation of varieties into sensitive and resistant ones. It was noted that on the 50th day of the experiment, the concentration of stress hormones increased, and growth hormones decreased when 50 mg/kg cadmium was introduced into the soil of. At the same time, the concentration of stress hormones in resistant varieties increased already on the 30th day, and in growth varieties – both on the 30th and on the 50th day, it did not decrease as much as in sensitive ones. There was a high activity of antioxidant enzymes in resistant varieties compared with sensitive ones. Resistant varieties showed generally high productivity when a cadmium dose of 50 mg/kg was applied to the soil. Sensitive varieties accumulated cadmium in aboveground biomass in greater quantities than resistant ones, while the differences became clear when a dose of cadmium of 50 mg/kg was applied. The results of the study confirmed that the differentiation of barley varieties in terms of resistance found during the assessment of the effects of cadmium on seedlings persists throughout the entire plant life cycle and affects yield and other economically valuable characteristics. The data obtained are useful for assessing the consequences of anthropogenic pollution of agrocenoses, the tasks of breeding varieties of main crops with high resistance to cadmium. In addition, the research materials can be used in the development of a methodology for assessing the state of soils contaminated with heavy metals and for environmental rationing tasks.