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An increase in the pesticide load in agro-cenoses leads to a decrease in the number of the main ecological and trophic groups of microorganisms, which causes a disruption of connections in agro-ecosystems and soil biological activity. For example, more than 95% of applied pesticides have a greater impact on soil microorganisms than on their target objects, as they are sprayed proportionally all over the field, regardless of the affected areas. In this case, fire treatment has the main benefit of a more targeted treatment, which is more focused on its main object of impact. But, as you know, fire can also cause significant damage to both soil and microorganisms living there. Soil microbiota is very sensitive to environmental changes, but it is completely killed only at soil temperatures above +120°C, so treatment with a fire cultivator that can work at both +100°C and +70°C has a high chance of becoming the safest way to control weeds. Despite the known negative effect of fires and flames on soils, to fully assess the impact of this method on soil and its fertility, it is necessary to investigate the impact of this treatment primarily on changes in the microbiological characteristics of the surface soil layer. The treatment was carried out using two modes of the fire cultivator (+70°C and +100°C). Microbiological analyzes of the soil were carried out according to generally accepted methods. The content of total biomass of microorganisms in the soil was determined by the rehydration method. Thus, to study the impact of fire cultivation on the direction of processes in the soil and the main ecological and trophic groups of microorganisms, we determined the content of total biomass of microorganisms, coefficients of mineralization-immobilization and oligotrophicity, cellulolytic activity, the number of bacteria, micromycetes, etc. Our analysis of the total microbial biomass of the selected soil samples allows us to assert the safety of the applied fire method of weed control. In the study of soil fouling lumps (Ashby's medium), 100% presence of bacteria of the genus Azotobacter was noted in all variants with temperature treatment. The analysis of soil samples on Ashby's medium showed that oligotrophs do not significantly change under fire treatment at 70°C, but some negative impact on the vital activity of these microorganisms is still observed under 100°C treatment. The obtained ecological coefficients of the direction of microbiological processes indicate the decreasing intensity of decomposition of soil organic matter, in particular humus compounds and reducing soil oligotrophicity indicates an increase in the content of nutrients in the soil. For the most environmental benefits, we recommend to use a milder fire treatment of 70°C, wich allows not only to control the weeds, but also stimulates and directs microbiological processes in a positive directio. [ABSTRACT FROM AUTHOR]

There are a number of questions that have remained relevant for a long time when using inoculants based on nodule bacteria. It has been shown that exopolysaccharides (EPS) producing bacterial cells play one of the key roles during interaction and during signal transmission in legume-rhizobial symbiosis, namely, bacterial survival, virulence of rhizobia, shelf life on inoculated seeds and in soil, and efficiency created legume-rhizobial system. In particular, it was found that new strains of soybean nodule bacteria Bradyrhizobium japonicum LG 2 and LG 5 synthesize EPS at 3.2 and 2.8 g/l, with an optical density above 0.8 rel. units, the viscosity of the culture liquid - within 270-302 mPa • s. The high level of synthesis and the chemical composition of EPS of the studied strains ensured the preservation of the viability of bacterial cells on the surface of seeds and on a solid medium. Inoculation of soybean seeds with a culture liquid containing EPS of strains LG 2 and LG 5 ensured the formation of an effective legume-rhizobial system, which is confirmed by the formation of 18-21 nodules / plant of soybeans with a nitrogenase activity of at least 2.9 µmol C2H4 / plant per hour. A graph model has been developed, which proves the direct dependence of the effect of EPS on the number of nodules formed on the roots, the level of nitrogenase activity of the legume-rhizobial system and their indirect effect on the yield and protein content in soybean grain. Prospects isolated by strains LG 2 and LG 5 of B. japonicum for biotechnological production of liquid and gel biopreparations. [ABSTRACT FROM AUTHOR]

The article presents original results of research. The dynamics of the balance and NPK use efficiency of the typical Ukrainian farm for monoculture cultivation during 2016‒2018 has been calculated. Laboratory analysis of soil (pH value, humus content, N, P2O5 and K2O) and grain (N and P2O5 content) was conducted in 2019. The negative dynamics of basic nutrient balance in the soil was revealed for 2016–2018 (nitrogen deficiency ranged from ‒30,6 to ‒130,9 kg/ha/year, phosphorus ‒ from ‒25,8 to ‒62,4 kg/ha/year, potassium ‒ from ‒34,3 to ‒244,5 kg/ha/year) and intensive pressures on the soil (NUE = 77,0‒260,3%, PUE = 171,3‒1902,3% and KUE = 115,8‒1429,8%). Soil pH was found on average 5,6 (category: close to neutral), the nitrogen content averaged 99 mg/kg (very low level), Р2О5 content ‒ 208 mg/kg (high level) and К2О ‒ 119 mg/kg (medium level) on the farmland areas. The ratio between nitrogen, phosphorus and potassium content in the soil of the studied land areas on average reaches 1:0,9:1,2 while the scientifically sound norm is 1:0,9:0,8. The average humus content is 1,93% (low level). The calculated indicators of nitrogen and NUE balance only in 2017 met the recommended standards of the UN Economic Commission for Europe. The PUE and KUE values in 2016 exceeded the average rate of phosphorus and potassium removal from the soil – 22 and 12 times, respectively. Changes of acidity over the last three years indicate the acidification of the soil environment, which is quite natural: only nitrogenous mineral fertilizers are applied to the soil, which is physiologically acidic, soil liming is not carried out, the green manure crops are not sown, organic fertilizers are not applied, and in crop rotation was a monoculture. The widespread practice of plowing crop residues into the soil without applying phosphorus and potassium fertilizers for three years does not meet the crop requirements for phosphorus and potassium and creates high one-way pressure on the soil. Consequently, relatively high sunflower and maize yields are generated from the existing high and medium content of these elements in the soil. The tendency of decreasing humus content in soil has been noticed. [ABSTRACT FROM AUTHOR]

Terrestrial ecosystems may provide an ideal setting for the acquisition and dissemination of antibiotic resistance, because they are frequently impacted by anthropogenic activities. The soil microbiome plays an important role in development and spread of antibiotic resistance in humans. The aim of our study was to detect the antibiotic resistance soil bacteria in different ecosystems: natural ecosystems, agroecosystems and urboecosystems. Were isolated 468 dominanting bacteria, among them 79 antibiotic resistant bacteria. All isolates were multi-drug resistant, of which greater than 74,5% were resistant to 9 antibiotics. A study of soil samples from the primeval forests showed that the microbial community characterized by a low content of antibiotic-resistant microorganisms. Among 78 isolated bacteria only two of them Bacillus cereus, and Pantoea agglomerans demonstrated high level of resistance to antibiotics. A total 106 strains were isolated from the soil of medicinal plants, 13 of them were antibiotic-resistant. The greatest numbers of antibiotic-resistant bacteria have been isolated from soil of urboecosystems and agroecosystems contaminated by enrofloxacin. Among the 284 tested bacteria 64 were antibiotic resistant. Multi-resistance were such pathogenic and conditionally pathogenic bacteria as: Enterococcus faecium, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, Bacillus licheniformis, Serratia fonticola, Hafnia alvei, Bacillus cereus, Bacillus megaterium and Clostridium difficile. [ABSTRACT FROM AUTHOR]

The content and stocks of carbon and the activity of microbiological destruction of organic matter in three types of chernozem soils in Ukraine have been investigated. An imbalance was found in the accumulation of the main components of the soil organic matter, as well as between mineralization processes, humus accumulation and degradation of cellulose in arable soils and their natural analogs. In the soil of natural ecosystems, the processes of mineralization -immobilization, destruction of organic matter and humus accumulation are balanced, which is confirmed by a high carbon pool (Ctot) and a fraction of Сmic in Ctot. In the soil of natural ecosystems processes of mineralization-immobilization, destruction of organ resources and humus-accumulating are balanced, which is confirmed by high-quality carbon pool and partial Сmic in Ctot. In agroecosystem is going destabilization of organic matter in the soil, which leads to a decrease of humus content in 1.1-1.5 times, stocks of organic matter - in 1.3-1.8 times. In arable soils, part of Соrg in the total soil carbon pool is 80-82% and 92-94% in the soil of the natural ecosystem. The losses of Соrg from chernozem soils in agroecosystem are 19-29% and this is due to a significant reduction in the content of Сmіc (63-71%). The application of different fertilizers causes destabilization of the soil microbial community, reduces microbial productivity and activates mineralization processes of organic matter, which leads to loss of Соrg and a decrease in the total carbon pool (Ctot) in the soil by 6-18%. The soil of natural ecosystems is characterized by a high content of Сmіc in the Соrg (3.14-3.70%), which indicates a high microbial productivity and fixation of organic substances in biomass of microorganisms. In the arable soils, was the low content of Сmіc in the organic matter of the soil (1.19-1.52%) which indicates the predominance of mineralization processes over the processes of humification. The application of exogenous mineral substances in the soil activates the processes of mineralization (Kmіn increases by 7-18%) and provides a high degree of using by microorganisms of soil organic matter (Kped increases by 6-9%). Organic fertilizers contribute to the formation of a maximum microbial pool, optimizing the structure of soil microbial community, decrease the intensity of mineralization processes (Kmіn) by 15-29% and the decomposition of soil organic matter by 6 to 37%. A significant difference in the parameters of the potential cellulolytic activity of the soil in the natural ecosystems and agroecosystems had been established. At the same time, the soil of natural ecosystems is characterized by a slight fluctuation of the emission CO2 (3.3-4.4 mg CO2 / kg of soils per day). [ABSTRACT FROM AUTHOR]