ACTIVITY OF ENZYMATIC CELLULOLYTIC COMPLEX AND ANTAGONISTIC PROPERTIES OF TRICHODERMA HARZIANUM 128

Objective. To study the activity of enzymes of the cellulolytic complex of the association of micromycetes Trichoderma harzianum 128 and their antagonistic activity; to study the possibility of the influence of fungal introduction to the composted substrate on the composting rate and quality of composts. Methods. Microbiological (for growing micromycetes in digest media, accounting the number of T. harzianum 128 and determining the antagonistic activity of the association), agrochemical (to determine the characteristics of composting chicken manure-based substrates and content of carbon and nitrogen in these substrates), biochemical (study of activity of cellulolytic enzymes), production inspection (on the basis of Agrofirma KOLOS LLC, Region of Kyiv). Results. The association of T. harzianum 128 micromycetes is characterized by high activity of exoglucanase, endoglucanase and β-glucosidase, which contributes to reduction in the composting time of organic matter upon the introduction of fungi to the chicken manure-based substrate. T. harzianum 128 has pronounced antifungal properties against pathogens of certain diseases of crops (Fusarium oxysporum, F. sulfurum, Nigrospora oryzae). Enrichment of composted substrates with the studied micromycetes provides their active development (up to 8,150 thous CFU/g of dry compost), accumulation of carbon and nitrogen in compost, which improves the quality of the final product. Conclusion. The association of T. harzianum 128 micromycetes is characterized by high activity of enzymes of the cellulolytic complex, has a pronounced antagonistic activity against pathogens of certain diseases of crops. The introduction of T. harzianum 128 to composted chicken manure-based substrates reduces the composting time and improves the quality of the final product, which can increase the productivity of agrocenoses by including biofertilizers in crop fertilization systems.

SPECIAL ASPECTS OF MIGRATION OF WATER-SOLUBLE ORGANIC SUBSTANCE AND BIOGENIC ELEMENTS IN SOD-PODZOLIC SOIL DEPENDING ON FERTILIZATION SYSTEM AND MICROBIAL PREPARATIONS

Objective. To study special aspects of vertical migration of products of biological transformation of organic matter and biogenic elements in sod-podzolic soil under different modes of root nutrition of plants. Methods. Lysimetric experiment, agrochemical, mathematical and statistical. Results. Based on studies conducted in a long-term lysimetric experiment on sod-podzolic soil, periodically washed type of water regime was established, as a result of which 37 mm of moisture, 23 kg/ha of water-soluble humic substances, nitrogen (NO3–) 55 kg/ha, calcium oxide 91 kg/ha and magnesium oxide 26 kg/ha magnesium oxide is lost at the background without inoculation per crop rotation when using mineral fertilization system. The use of microbial preparations reduces the loss of these elements to 33 mm, 20 kg/ha, 52 kg/ha, 83 kg/ha and 25 kg/ha, respectively. It was established that the average infiltration of moisture from the layer 0–155 cm under crops of continuous sowing was 25–37 mm at the background without the use of microbial preparations and 22–33 mm at the background of inoculation. The mineral fertilizer system increased the losses of the soil solution by 9 mm and 7 mm versus the control variants, respective to the backgrounds. The lowest losses of productive moisture were reported in the variants where sidereal fertilizers were used. When replacing the mineral fertilization system with sidereal-mineral and organo-mineral fertilizers without compromising the yield of crop rotations, it is possible to reduce the loss of productive moisture by 1.5 times, reduce the loss of labile soil organic matter by 1.7–1.8 times, nitrate nitrogen by 8–10 %, calcium by 18–24 % and magnesium by 40–50 %. Due to the use of biopreparations, there is a reduction in losses of nitrate nitrogen by 5–18 %, magnesium — by 5–14 %, calcium — by 6–16 %. Conclusion. To reduce non-productive losses of moisture, water-soluble organic matter and biogenic element compounds, it is advisable to use green mass of green manures and microbial preparations at the background of the mineral system and fertilizer system NPK+manure. The use of microbial preparations helps to reduce the loss of nitrate nitrogen by 5–18 %, magnesium — by 5–14 %, calcium — by 6–16 %.

INFLUENCE OF SOIL TREATMENT ON THE NUMBER OF EARTHWORMS AND THE SIZE OF MICROBIAL BIOMASS UNDER THE CONDITIONS OF AGRICULTURAL INTENSIFICATION

Objective. To establish the influence of soil treatment methods on the number of earthworms and microbial biomass in dark-chestnut heavy loam soil with observance of the following crop rotation: soybean – winter wheat – corn; verify the hypothesis of the negative influence of traditional soil treatment technologies on the number of earthworms. Methods. Analytical, field, laboratory, system analysis, statistical. Results. During the studies conducted in 2018–2021 at Askanian State Agricultural Experimental Station of the Institute of Irrigated Agriculture of the NAAS, the positive influence of zero soil treatment technologies on the studied parameters versus with traditional technologies was established. A 2.5-fold increase in the number of earthworms and a 1.1-fold increase in microbial biomass was reported with zero soil treatment technologies. The interaction between soil treatment factors and cover crops in the structure of crop rotation was 23.7 %. Soil treatment technologies had a negligible influence on the size of microbial biomass — at the level of 1.4 %. The significance of the action of cover crops in crop rotation was 10.0 %. The experiment also showed a higher number of earthworms in the soil with zero soil treatment technologies with cover crops and traditional technologies for control, due to better live environment and favourable conditions for reproduction and distribution of the population depending on soil treatment technologies. Changes in the density of the soil layer 0–30 cm were within the measurement error (for zero soil treatment technologies the studied parameter was 1.23 g/cm3, for traditional — 1.24 g/cm3). Compaction of 0–20 cm soil layer with zero and traditional soil treatment technologies was reported. The content of soil organic matter by the years of studies under zero soil treatment technologies increased to 3.0 %, which is 1.2 times higher than with traditional technologies. Conclusion. Under the conditions of stationary field experiment the positive influence of zero soil treatment technologies on early changes of biological properties of soil, which were characterized by increase in number of earthworms and size of microbial biomass, has been established. The positive influence of cover crops on soil quality was determined, which was characterized by signs of biota activation in the 0–30 cm layer and improvement of biological and physical properties of the soil.

SCREENING OF MODERN CHICKPEA VARIETIES BY RESPONSE TO BACTERIZATION

Objective. To screen modern varieties of chickpeas of Ukrainian selection by the response to bacterization, to identify varieties characterized by high increases in symbiotic activity and yield. Methods. Biotesting, gas-chromatographic, field experiment, statistical. Results. The response to bacterization of chickpea seeds of different varieties was studied in a field experiment in the southern region of Ukraine (Region of Odesa). As a result of inoculation of chickpea seeds with a bacterial suspension of an effective strain of Mesorhizobium ciceri ND-64, a significant increase in nodulation activity was registered. The highest increase in the number of nodules (51.6 % and 53 %) was reported for the varieties Odysei and Triumf. Upon seed inoculation with the studied strain, a significant increase in the weight of nodules of the Triumf variety (2.3 times) was shown. In the control variants, the nitrogenase activity in the nodules of Skarb variety plants was the highest (425 nmol C2H4/plant per hour), and in the Budzhak variety it was the lowest (159 nmol C2H4/plant per hour). Inoculation of seeds with bacterial suspension of M. ciceri ND-64 contributed to a significant increase in the studied parameter in the varieties Budzhak, Pamiat, Odysei and Triumf. The latter was characterized by the most significant response to inoculation with an effective strain in terms of nodulation and nitrogenase activity. Symbiotic parameters showed the weakest ability to respond to inoculation in terms of symbiotic parameters in Skarb variety. Pamiat variety was characterised by the maximum number of seeds per plant (18.5 units/plant). However, as a result of inoculation of chickpea seeds with M. ciceri ND-64, the number of seeds increased the most in the variety Skarb and amounted to 28.7 units/plant. In terms of seed weight, the Triumph variety was superior (9.5 g/plant). The yield of all studied varieties of chickpeas after bacterization of seeds with M. ciceri ND-64 significantly exceeded the control variants (without inoculation) by 21–56 %. The highest increase in control was observed for the varieties Triumph (0.49 t/ha) and Skarb (0.56 t/ha). The ability of nodule bacteria M. ciceri ND-64 to intensive synthesis of phytohormones and the formation of highly effective symbiosis with chickpea plants of different varieties provided a complementary interaction of rhizobia with plants and a significant increase in crop yield. Conclusion: Due to the interaction with aboriginal nodule bacteria, the highest parameters of nodulation and nitrogenase activity were typical for the varieties Triumf and Skarb, yields for Triumf and Budzhak. Screening of varieties by the response to inoculation with an effective strain of M. ciceri ND-64 indicates an increase in symbiotic activity in varieties Triumf, Budzhak (large-seeded), Pamiat (medium-seeded). The maximum increase in yield as a result of inoculation was found in chickpea varieties Skarb and Triumf. M. ciceri ND-64 are capable of active synthesis of substances of phytohormonal nature, which contributes to the effective interaction between rhizobia and chickpea plants.

EFFICACY OF TRICHODERMA VIRIDE STRAIN WITH HIGH ANTAGONISTIC AND CELLULOLYTIC ACTIVITY

Objective. To study the efficacy of the use of a new strain of Trichoderma viride IMB F-100076 with high antagonistic and cellulolytic activity, in particular its effect on the photosynthetic apparatus and the yield of corn plants. Methods. Study of the effect of T. viride IMB F-100076 on corn94 yield was performed under the conditions of a three-year small-plot field experiment on sodmedium-podzolic soil. The content of chlorophyll a and b in the plants of the experimental variants was determined by spectrophotometry. Methods of mathematical statistics were used in processing the obtained data. Results. Data from a three-year field experiment showed that the application of straw had a negative effect on the yield of corn, which averaged 7.72 t/ha that is 12.3 % less than in the variant without the application of straw (control). Application of the antagonist fungus T. viride IMB F-100076 to the soil simultaneously with straw allowed to obtain an average yield of 9.5 t/ha during three years of study, which is 23 % higher than in the variant with straw. In the control variant (without application of straw and fungal suspension), the yield averaged 8.8 t/ha, which is 14 % higher than in the variant with straw not treated with fungus. It was shown that the content of chlorophylls in corn leaves increases under the influence of T. viride IMB F-100076. For instance, the total content of chlorophyll a and b was 261.04 mg/100 g of leaves, which is 39.0 % higher than in the variant with straw not treatment with a suspension of the fungus, and 15.3 % higher than in the control variant. The obtained results highlight that the treatment of straw with the fungus T. viride IMB F-100076 had a positive effect on the formation of the photosynthetic apparatus of corn plants. Conclusion. Simultaneous application of wheat straw and T. viride IMB F-100076 micromycete, which is characterized by high antagonistic and cellulolytic activity, provides a significant increase in corn yield versus the variant with straw not treated with fungus. The content of chlorophylls a and b in the leaves increases.

DIAZOTROPH ACTIVITY REGULATING STRATEGY UNDER THEIR INTRODUCTION IN AGROCENOSES

Objective. Investigate approaches to managing the activity of soil diazotrophs and propose a strategy for its regulation. Methods. Theoretical, vegetation and field experiments, microbiological, gas chromatographic, mathematical and statistical. Results. The activity of beneficial soil microorganisms can change under the action of temperature, humidity, chemical compounds of various origin, and other microorganisms. It was established that, taking into account a significant variety of factors, it is necessary to develop a set of specific ways to increase the growth and functional activity of nitrogen-fixing bacteria, as well as their viability. It has been proved that the combination of diazotrophs forms an effective symbiotic leguminous-rhizobial system, which provides additional biological nitrogen in agrocenoses. At the same time, there was an increase in plant mass, chlorophyll content in the leaves, protein and oil content in the products. The combined use of diazotrophs increases the yield, in particular, soybeans by 9–16 % compared with inoculation by pure bacterial culture. Conclusion. Based on the analysis and generalization of the obtained research results, a strategy for regulating the activity of diazotrophs for their effective introduction into agrocenoses is proposed, which consists in combining bacteria of different species, selecting conditions for their co-cultivation and application upon stabilisation of the number of viable bacterial cells. The proposed strategy involves solving the problem by obtaining an inoculant, which is characterized by a high titre and a stable number of viable cells, which allows to obtain an effective nitrogen-fixing system. The strategy is tried-and-tested on the example of regulating the growth and functional activity of soybean nodule bacteria by combining diazotrophs of different species, substantiating the conditions of their co-cultivation and application to ensure positive interaction in the form of commensalism, as well as by regulating viability of diazotrophs by adding stabilisers to the medium.

INFLUENCE OF DIFFERENT SYSTEMS OF CROP FARMING ON ECOLOGICAL AND TROPHIC GROUPINGS OF MICROORGANISMS OF TYPICAL CHORNOZEM IN THE CONDITIONS OF THE LEFT-BANK FOREST STEPPE OF UKRAINE

Objective. To establish the influence of different crop farming systems on the parameters of the number of representatives of ecological and trophic groups of microorganisms in typical chernozem. Methods. Comparative-profile-genetic, microbiological, statistical. Results. The upper 0–10- centimetre layer of soil (the number of microorganisms decreases with depth and the predominance of microbiological activity in the 10–20-centimetre layer is possible only in dry periods) is characterised by the highest microbiological activity. The microbiocenosis undergoes the greatest transformations in the conditions of intensive system of crop farming upon mixing and turn of a layer. This is expressed in a significant decrease in microbiological activity in the 0–10-centimetre layer and vice versa — an increase in the layers of 10–20 and 20–30 cm. Agrogenic soils have higher parameters of total microbiological activity compared to the fallow area. The most positive influence on biogenesity was reported in the variants of the organic system of crop farming, especially with the use of green manures. The data on the directions of development of soil biological processes of the studied variants by the analysis of oligotrophic coefficients, mineralization-immobilization and mobilization of nitrogen stock are provided. Mathematical analysis of the data showed a significant influence of the depth of sampling on the number of all studied microorganisms, while the crop farming system significantly affected the number of microscopic fungi, actinomycetes and amylolytic microbiota. Conclusion. Agrogenic use of chernozems reduces the number of microscopic fungi. In the variants of organic crop farming, a significant increase in the number of actinomycetes and amylolytic microbiota was reported. Under the intensive system of crop farming, there is a decreased number of representatives of all studied ecological and trophic groups of microorganisms. And vice verse, variants of the organic crop farming system, especially under the use of green manure, have a higher number of most functional groups of microorganisms. Cultivated soils are characterized by a higher coefficient of mineralization and immobilization compared to fallow.

INFLUENCE OF REGIMES OF USE AND FERTILIZATION OF SPONTANEOUSLY RENEWABLE SWARD ON THE COURSE OF SOIL MICROBIOLOGICAL PROCESSES

Objective. To study the state of the soil microbiocenosis of spontaneously renewable phytocoenosis of the 21st year of self-growth after the application of mineral fertilizers at the dose of N90P40K70 and the two-mow regime. Methods. Experimental-field, laboratory-analytical, microbiological, statistical. Results. Optimization of mineral nutrition of renewable phytocoenosis contributes to an increase in the number of microorganisms: ammonifiers 2.24 times, mineral nitrogen immobilizers — 1.39, denitrifiers — 3.19, nitrifiers — 1.71, cellulose-destructive — 1.64, actinomycetes — 1.17, micromycetes — 1.20, organophosphate mobilizers — 1.33 times. As a result of twomow regime of the use grass cenoses, the number of microorganisms in most of the studied groups does not change, except for denitrifiers, cellulose-destroying bacteria, micromycetes and organophosphate mobilizers. The use of mineral fertilizers leads to a slowdown of mineralization processes in the soil: pedotrophicity index decreases by 2.28 times, the coefficient of mineralization of nitrogen compounds — by 1.60 time, oligotrophicity — by 2.25 times, the activity of humus mineralization — by 1.65 times. Alienation of plant biomass has a negligible effect on the course of microbiological processes in the soil: pedotrophicity index increases by 18.2 %, oligotrophicity coefficient — by 3.63 %, nitrogen mineralization coefficient decreases by 6.6 %, humus mineralization activity — by 6.2 %. Conclusion. Lack of mineral elements in the soil of the fallow provokes the intensification of mineralization processes, and the optimization of mineral nutrition of phytocoenosis plants contributes to their slowing down. The decrease in the total biological activity and the increase in the phytotoxicity of the soil with the two-mow use of sward indicate the beginning of the processes of soil depletion.

INFLUENCE OF NODULE BACTERIA STRAINS OF SINORHIZOBIUM MELILOTI ON THE AMINO ACID CONTENT IN THE TOPS OF ALFALFA UNDER DIFFERENT WATER SUPPLY

Objective. To study the amino acid composition in the tops of alfalfa under different water supply (60 % MVC (maximum water capacity) and 30 % MVC) depending on the inoculum strain (Sinorhizobium meliloti 425a, T17, AC08). Methods. Microbiological (bacterial cultivation), physiological (vegetation experiment), biochemical (determination of amino acid content in the tops of plants). Results. It was established that the qualitative amino acid composition in the tops of ALFALFA was identical in all variants. However, quantitative content of the studied samples differed depending on the inoculum strain and water supply. It was found that aspartic and glutamic acids, leucine and lysine are dominant in the tops of alfalfa under different water supply. In the absence of moisture, an increase in the content of individual amino acids was reported at the background of Sinorhizobium meliloti AC08 and T17, while inoculation with Sinorhizobium meliloti 425a resulted in a decrease in the content of all amino acids except tyrosine. In plants exposed to water stress, a tendency towards decrease in the content of glutamic acid at the background of bacterization with Sinorhizobium meliloti 425a and increase — under inoculation with Sinorhizobium meliloti T17 and AC08 was reported, which may support the use of the latter to increase the ability of symbiotic systems to recover during a post-stress period. Conclusion. Pre-sowing inoculation of alfalfa of the variety Laska with new active strains of Sinorhizobium meliloti AC08 and T17 helps to increase the content of amino acids, in particular essential, in the tops of plants, both under optimal conditions of moisture and insufficient water supply. The prospects of using new strains of rhizobia in the cultivation of alfalfa for green mass under the conditions of optimal water supply and drought has been verified.

INFLUENCE OF EXOMETABOLITES OF DIFFERENT VARIETIES OF CULTURAL PLANTS ON THE GROWTH AND DEVELOPMENT OF PATHOGENIC MICROMYCETES BIPOLARIS SOROKINIANA AND ALTERNARIA ALTERNATA

Objective. To establish the influence of exometabolites of winter wheat plants of Podolianka, Natalka, Skagen, Mulan varieties and oats of Skarb Ukrainy, Svitanok, Tembr varieties on the growth and development of Bipolaris sorokiniana micromycete, as well as the influence of onion of Tkachenkivska, Mavka, Veselka, Liubchyk, Variah, Harmonia varieties on the growth and development of the micromycete Alternaria alternata. Methods. Mycological, phytopathological, phytoimmunological. Results. Two hundred isolates of pathogenic micromycetes were isolated from the seeds of the studied crops of different varieties. The most common microbiota were: Bipolaris sorokiniana, Alternaria alternata, Alternaria tenuissima, Alternaria infectoria, Stemphylium vesicarium, Curvularia inaequalis. The highest incidence on wheat and oat seeds (over 80 %) was reported for B. sorokiniana, on onion seeds — for A. alternata. It was found that exometabolites of plants of different varieties can both inhibit and stimulate the rate of radial growth of mycelium of B. sorokiniana and A. alternata. It was proved that exometabolites of plants of wheat, oats, onion can significantly affect the reproductive capacity of the studied micromycetes, which reduced the number of spores per 1 cm2 of colony area almost 1.2–2.5 times compared to the control. This indicates that exometabolites of plants are characterized by fungicidal properties, which are due to a complex of biologically active substances that can inhibit the intensity of sporulation of B. sorokiniana and A. alternate. Conclusion. The antifungal property of root exometabolites of plants of the studied varieties significantly depends on the genotype of the variety. Therefore, an important timely task is to identify environmentally stable and flexible varieties that are characterized by group resistance to pathogens of fungal origin, as well as the search for mechanisms of action of fungicidal natural origin.