Meadow Chernozem Soil Research Articles

Influence of Bacterial Fertilizers on the Structure of the Rhizospheric Fungal Community of Cereals South of Western Siberia

The general lack of knowledge on the conditions of Western Siberia (Omsk region) and the taxonomic diversity of zonal soils determines the relevance of these studies. The research was carried out in order to study the effect of complex biologics on the taxonomic diversity of the fungal component of the microbiome of the rhizosphere of cereals and the phytosanitary condition of crops in the southern forest-steppe (meadow-chernozem soil) and subtaiga (gray forest soil) zones of the Omsk Irtysh region (Western Siberia). This work was carried out in 2022–2023, using laboratory studies in combination with field experiments and metagenomic and statistical analyses. The objects of research were varieties of cereals and grain forage crops of Omsk selection: soil microorganisms. The scheme of the experiment involved the study of the following options: varieties of cereals (factor A): spring soft wheat—Omsk 42, Omsk 44, Tarskaya 12; durum wheat—Omsk coral; barley—Omsk 101; oats—Siberian hercules; bacterial preparation for seed inoculation (factor B) without the drug—Mizorin and Flavobacterin. The sampling of the plant rhizosphere for metagenomic analysis was carried out during the earing phase (July). For the first time, the taxonomic composition of the fungal community was determined based on the analysis of amplicon libraries of fragments of ribosomal operons of ITS2 fungi during colonization of crop roots by nitrogen-fixing bacteria in various soil and climatic zones of the Omsk region. The fungal component of the microbiome was analyzed in two zones of the Omsk region (southern forest-steppe and subtaiga). The five dominant phyla of soil fungi were located in the following decreasing series: Ascomycota (about 70%) > Mortierellomycota (about 7%) > Basidiomycota (about 5%) > Mucoromycota (3%) > Chytridiomycota (1%). The five main genera of fungi inhabiting the rhizosphere of cereals are located in a decreasing row: Giberella (6.9%) > Mortierella (6.6%) > Chaetomium (4.8%) > Cladosporium (3.8%) > Rhizopus (3.3%). The predominantly positive effect of biologics of associative nitrogen fixation on the fungal community of the soil (rhizosphere) of experimental sites located in different soil and climatic zones has been established. During seed bacterization, the growth of saprotrophic fungal genera was noted in relation to the control variants Pseudogymnoascus, Chloridium, Clonostachys, Trihoderma, etc., and the fungicidal properties of bacterial strains introduced into the soil were actively manifested relative to phytopathogenic fungi of the genera Alternaria, Blumeria, Fusarium, etc. According to the results of determining the number of infectious structures of Rhizoctonia solani, it was found that the population of the soil with viable cells of this pathogen was 1–3 pcs/g (below the threshold of harmfulness, PV 20 pcs/g of soil), which indicates a favorable phytosanitary situation with respect to the pathogen. The fungicidal effect of the applied bacterial fertilizers on Rhizoctonia solani could not be detected. The number of Bipolaris sorokiniana varied depending on the drug used. In the conditions of the southern forest-steppe zone of the Omsk region (meadow-chernozem soil), the greatest fungicidal effect was noted in Flavobacterin application variants on wheat of the Omsk 42 variety, durum wheat of the Omsk coral variety, and barley; the decrease in conidia relative to the control was 73, 35, and 29%, respectively. In the subtaiga zone of the Omsk Irtysh region (gray forest soil), as in the southern forest-steppe zone, pre-sowing bacterization of seeds with Flavobacterin led to a decrease in Bipolaris sorokiniana in the rhizosphere of wheat of the Omsk 42 variety by 18%, and oats by 27%, to control. The use of the drug Mizorin in some variants of the experiment led to an insignificant decrease in the harmful fungus or had no effect at all.

Response of oilseed flax to different level of mineral nutrition in the forest-steppe of Western Siberia

The article presents the results of studying the influence of nitrogen and phosphorus fertilizers on the water regime of meadow-chernozem soil, yield and oil content of flax seeds in 2022–2023. on a stationary experiment at the field forage production laboratory of the Federal State Budgetary Institution “Omsk ASC” in the conditions of the southern forest-steppe of the Omsk region. The objects of observation are oilseed flax of the Northern variety and meado-chernozem soil. The scheme of the experiment included the following options: factor A — medium soil availability of mobile phosphorus (50-100 mg/kg according to F.V. Chirikov, background 0), increased (100–120 mg/kg, background I and 140–150 mg/kg, background II), high (150– 200 mg/kg, background III); factor B — phosphorus fertilizer (P0, P60); factor C — nitrogen fertilizer (N0, N30, N60). In this case, nitrogen and phosphorus fertilizers were superimposed on backgrounds of varying soil phosphorus supply. Climatic factors (temperature and precipitation) determined the initial reserve of total moisture in the soil when sowing oil flax, which was at the level of 82% of the lowest moisture capacity in a meter layer and did not depend on the background phosphorus supply. Mineral fertilizers increased crop productivity. Its highest yield was observed against the background of an increased supply of soil with mobile phosphorus (1.71 t/ha) with the pre-sowing application of ammonium nitrate and ammophos. The oil content of flax, on the contrary, decreased when using fertilizers. Its highest indicators (39.5%) were observed against background II when using phosphorus fertilizers.

ВЛИЯНИЕ АГРОТЕХНОЛОГИИ ВОЗДЕЛЫВАНИЯ ГОРОХА НА БИОЛОГИЧЕСКИЕ И АГРОХИМИЧЕСКИЕ СВОЙСТВА ЛУГОВО-ЧЕРНОЗЕМНОЙ ПОЧВЫ

The aim of research is to establish patterns of changes in biological and agrochemical parameters of meadow-chernozem soil with long-term use of resource-saving treatments and chemicalization means in the conditions of the southern forest-steppe of Western Siberia. Stationary studies were conducted in the forest-steppe of the Omsk Region in a grain-fallow crop rotation (fallow – wheat – peas – wheat – barley) under a pea crop at the Omsk Agricultural Research Center. The parameters of changes in the number of individual physiological groups of microorganisms and indicators of biological activity of meadow-chernozem soil under peas were established using agricultural technologies with different levels of intensification, including the minimum-zero tillage system in crop rotation. It was determined that when using complex chemicalization agents in combination with No-till technology of soil cultivation, the activity of bacteria capable of fixing atmospheric nitrogen increased by 34 %, saprotrophic and amylolytic microorga¬nisms – by 13 and 17 % in relation to the control, respectively. The activity of the oxidation-reduction enzyme catalase when using intensification agents, regardless of the technology of pea cultivation, decreased to 28 % of the control. The use of intensification agents led to an increase in the content of nitrate nitrogen in the soil during the budding period, mobile phosphorus by 4 or more times. When assessing the anthropogenic impact on soil microflora, we used the definition of total biological activity, including all the studied biological tests in relative percentages. According to this indicator, soil cultivation options are arranged in a row in ascending order: combined < moldboard < minimum-zero.

Application of nitrogen fertilizers to spring wheat on meadowchernozem soil in the Omsk Irtysh region

Application of nitrogen fertilizers to spring wheat on meadowchernozem soil in the Omsk Irtysh region

АГРОХИМИЧЕСКИЕ И БИОЛОГИЧЕСКИЕ СВОЙСТВА РИЗОСФЕРЫ СОИ ПРИ ПРИМЕНЕНИИ БАКТЕРИЗАЦИИ СЕМЯН

The aim of the study is to evaluate the effect of pre-sowing bacterization of soybean seeds with strains of the biopreparation Rizotorfin on the agrochemical and biological properties of the rhizosphere. The study was conducted in the conditions of the southern forest-steppe of Western Siberia. The object of the study was new varieties bred by the Omsk Agrarian Scientific Center – Sibiriada and Sibiriada 20. The soil of the experimental plot is meadow-chernozem medium-deep heavy loamy with a humus content of 6.5 %. The study of the microbial pool of the meadow-chernozem soil was carried out in a field experiment to evaluate the effect of pre-sowing bacterization of seeds on the agrochemical and biological pro¬perties of the soybean rhizosphere. In the root zone, the content of nitrate nitrogen (N-NO3), the number of agronomically significant groups of microorganisms, and the direction of soil-microbiological processes were determined. Against the background of the use of microbiological preparations, the amount of nitrate nitrogen did not change significantly. The changes in amylolytic and saprotrophic microflora are presented, reflecting the direction of soil-microbiological processes in the rhizosphere of soybean varieties, where immobilization processes were predominant. Inoculation of Sibiriada 20 soybean seeds with Rizotorfin promoted activation of the soil organic matter transformation process, the transformation coefficient varied from 61.0 to 132.7, reaching maximum values when using strain BP 835. In the root zone, a significant increase in saprotrophic microflora was observed in the Sibiriada 20 variety when bacterizing seeds with Rizotorfin, strain 634 (72 % of the control). Microorganisms of the tested group in the rhizosphere of the Sibiriada variety experienced depression when introducing strains of symbiotic nitrogen fixers into the soil, the decrease was 32 and 63 % of the control, which may be due to the genotypic characteristics of the varieties. The activity of amylolytic microorganisms changed with a tendency similar to saprotrophic bacteria. The highest efficiency of inoculation on the yield of soybean grain was noted in 2022. In the extremely dry conditions of 2023, a reliable effect of the bacterization factor on crop productivity was revealed. The most effective strain for the Sibiriada variety was BP 634 (+0.44 t/ha), for the Sibiriada 20 variety – strain BP 835 (+0.42 t/ha).

ВЛИЯНИЕ ПРИМЕНЕНИЯ СРЕДСТВ ИНТЕНСИФИКАЦИИ НА БИОЛОГИЧЕСКУЮ АКТИВНОСТЬ И ФИТОСАНИТАРНОЕ СОСТОЯНИЕ ПОЧВЫ ПОД ПОСЕВОМ ГОРОХА

The aim of research is to determine the parameters of biological activity of meadow-chernozem soil and its phytoimmunity in grain-fallow crop rotation at different levels of cultivation intensification and the use of chemicals. The studies were carried out in a long-term (launched in 1973) stationary experiment in grain-fallow crop rotation (fallow – wheat – peas – wheat – barley) under pea crop in the Federal State Budgetary Scientific Institution Omsk Agrarian Scientific Center. In certain periods of 2022 and 2023, with favorable soil moisture, the presence of a significant amount of plant residues in the variant with minimum-zero tillage and the use of complex chemicals, the number of soil micromycetes and nodule bacteria increased to 93.0 thousand and 13.9 million CFU/g, respectively. The total number of soil microflora in the arable layer under different soil cultivation systems for peas without the use of complex chemicals was 51.4–61.2 million CFU/g with a difference of 19.0 % in the ascending series: No-till < moldboard < combined. The use of mineral fertilizers in combination with plant protection products in moldboard and combined tillage did not have a significant effect on the amount of soil microflora, a slight decrease to 17.0 % within the experimental error was noted. In the variants with No-till tillage in combination with intensification products, stimulation of the growth of the number of microorganisms to 22.0 % in relation to the control was noted. On average, according to the soil tillage factor, the greatest development of pea root rot was observed in the No-till variant (3.8 %), a slight decrease (3.2–3.6 %) – in moldboard and combined tillage. The use of plant protection products during the growing season of peas made it possible to reduce the development of root rot by 47.0 % relative to the control, depending on the soil tillage method. With combined treatment, the greatest prevalence of pea root system disease was noted (37.8 %), the least – with No-till treatment (30.8 %). In laboratory conditions, using the wet chamber method, a complex of root rot pathogens was determined, among which fungi of the genus Fusarium spp. prevailed.

Оценка пригодности почв для возделывания картофеля

Abstract. The purpose of the study is to assess the suitability of soils for growing potatoes according to the requirements for the crop under study. Conduct a grouping of soil types in the study area according to fertility indicators. To form an optimization model in terms of fertility indicators relative to the requirements for the cultivation of potatoes. Methods. The object of the study is the territory of the northern forest-steppe of the Tyumen region. The studies were carried out on the basis of an analytical method using the following tools: at the first stage, the technology for creating a digital soil map of the South of the Tyumen region was carried out; at the second stage, a modeling method was used to develop an optimization model of soil fertility indicators; data of long-term research of the Department of Soil Science and Agrochemistry of the State Agrarian University of the Northern Trans-Urals. Scientific novelty. Work has been carried out to create a digital soil map of the south of the Tyumen region. 52 genetic types of soils were identified, the maximum area in the region falls on bog high-moor peat soils – 32.1 %, the minimum meadow-chernozem solonetsous and podzolized chernozems – 0.1 %. Taking into account the parameters of soil fertility, using the modeling method, an optimization model has been developed in the context of soil grouping by fertility. Results. The most favorable in terms of fertility for the cultivation of potatoes are the following types of soils - gray forest podzolized, dark gray forest solodized, ordinary solonetzic chernozems, podzolized chernozems, leached chernozems and meadow chernozem soils, since their initial fertility indicators are closer to the required conditions for potato cultivation. With regard to the content of nutrients in the soil, here it is necessary to take into account through laboratory studies. However, when selecting soils from the presented model, one can understand how much nutrients need to be added to the soil with fertilizers in order to provide optimal nutrition for potatoes.

Balance of humus and nutrients in the meadow-chernozem soil of the rice ecosystem

Balance of humus and nutrients in the meadow-chernozem soil of the rice ecosystem

Growth regulators in the technology of cultivation of topinambour of the Skorospelka varie-ty

The results of field studies of the effectiveness of growth regulators Epin-Extra and Agat-25 Super in meadow-chernozem soil conditions of Penza region are presented. It is established that growth regulators play an important role in the passage of development phases and contribute to the physiological activity of the most important processes in topinambur plants. The research on studying the peculiarities of plant formation and yield of topinambour of the Skorospelka variety during tuber treatment, foliar treatment, complex treatment of tubers and double foliar treatment of plants with growth regulators Epin-Extra, Agat-25 Super was carried out. The growth regulators and their application according to the experiment scheme improved the indices of topinambur tuber yield structure and green mass in relation to the control. It was found that topinambur had the following indicators: plant height varied between 165-187.6 cm, the largest mass of the above-ground part was 1237.1 grams, the tuber yield was 26 t/ha. When forming high tuber yield, there is a direct correlation between the use of growth regulators and the method of treatment, and as a consequence of their effect on the growth and development of plants in general.

Effect of sufficient and deficit irrigation with different salt inputs on the yield of cucumber

Soil salinisation is considered one of the major environmental hazards threatening agricultural productivity and can be accentuated by climate change as well as the use of low-quality water in irrigation. This is the case in our study area which is affected by secondary salinisation due to the use of saline irrigation water for horticultural production. Deficit irrigation technique is implemented especially in arid and semiarid regions due to its potential to optimise water productivity while maintaining or increasing crop yield. The main objective of this study was to compare the effect of irrigation with sufficient (SD) and deficit (DD) doses. This research was carried out in Karcag in 2020. Cucumber was grown on a meadow chernozem soil and was irrigated with SD and DD of two irrigation water qualities. Soil moisture was monitored and crop yields were recorded. Despite the differences in quality and quantity of water, the application of less water by DD maintained the same yield as SD. We found a non-significant difference between the average soil moisture contents under the treatments (15.5 v/v% for SD and 13.5 v/v% for DD). Deficit irrigation can be an efficient technique due to its potential for improving water use efficiency, maintaining sufficient soil moisture content favourable for proper crop development and yield.

Effect of Long-Term Fertilizer Application on Soil-Inhabiting Micromycetes of Meadow Chernozem Soil under Wheat Crops

Effect of Long-Term Fertilizer Application on Soil-Inhabiting Micromycetes of Meadow Chernozem Soil under Wheat Crops

The Effect of Long-Term Use of Fertilizers on Soil-Dwelling Micromycetes of Meadow Chernozem Soil in Wheat Crops

The Effect of Long-Term Use of Fertilizers on Soil-Dwelling Micromycetes of Meadow Chernozem Soil in Wheat Crops

Influence of the Duration of the Use of Perennial Grasses on the Fertility of Irrigated Meadow-Chernozemic Soils in the Omsk Irtysh Region

Influence of the Duration of the Use of Perennial Grasses on the Fertility of Irrigated Meadow-Chernozemic Soils in the Omsk Irtysh Region

Физико-химическая оценка почвы в технологии выращивания озимого тритикале

In the experiment, it was found that the productivity indicators of the aboveground mass of winter triticale of the Tribune variety and the content of nitrogen, phosphorus and potassium in their plant tissues are generally consistent with water-physical, physico-chemical parameters and with soil bonification data. It was found that there were no differences in the mass of green leaves and the dry mass of the aboveground part of triticale on chernozem typical of agrocenosis and virgin soil. Of the forest soils, the smallest mass of triticale leaves was obtained on gray forest and turf alluvial, and the largest on sod–podzolic light loamy soil. Plants with massive leaves were also obtained on alluvial meadow soil of the same light loamy granulometric composition. The water content of triticale leaves, as a rule, does not depend on soil fertility. Only on the chernozem-meadow soil of the trunk strips of the apple orchard, in contrast to the row-to-row soil, the hydration of the leaves turned out to be significantly higher. This can be explained by a less acidic reaction, greater hygroscopicity and nitrogen content in the soil of the trunk strip. In summary, winter triticale plants are recommended to be used as a test crop when assessing the degree of soil cultivation. Keywords: WINTER TRITICALE, DEGREE OF CULTIVATION, BIOINDICATION, APPLE ORCHARD, NATURAL LANDS

Effect of mineral fertilizers on sorghum crop yields in the southern forest-steppe of Western Siberia

The results of studying the productivity of sorghum crops under different conditions of mineral nutrition on meadow-chernozem soil of the southern forest-steppe of Western Siberia are presented. The study was conducted in 2019–2022 in the Omsk region as part of a long-term stationary field experiment. The soil of the experimental plot is meadow-chernozem moderately deep heavy loamy soil. The arable horizon is characterized by neutral reaction of the soil solution (pH 7.0–7.2). The scheme of the experiment is two-factor, includes application of nitrogen (N0, 30, 60) and phosphorus (P0, 60) mineral fertilizers before sowing sorghum crops. The dynamics of moisture content in the meter soil profile is closely related to the hydrothermal conditions of vegetation periods. In the most wetted year of 2019, the soil profile had a more stable and uniform moisture content, especially in the second half meter. In subsequent years, the atmospheric moisture deficit was clearly manifested in the content of total moisture both along the soil profile and in time. Drying out of the meter profile even in the initial growing season was observed in 2022, which can be considered as a result of low residual moisture in the preceding, also dry, season. In the control, mineral nutrition was limited by the low content of mobile phosphorus. The studies have shown that in conditions of insufficient and unstable moisture, typical for the south of Western Siberia, it is advisable to cultivate sorghum crops with high responsiveness to the use of mineral fertilizers in field fodder production. In the average of two years, the maximum yield of green mass of sugar sorghum on intensive background was 21.07 t/ha, sorghum-sudangrass hybrid – 16.62 t/ha, which is higher than the control by 47.2 and 62.7%, respectively. The most effective was the complex application of mineral fertilizers, which provided an increase in dry matter content of sugar sorghum from 3.97 to 6.08 t/ha (53.0%), sorghum-sudangrasas hybrid – from 2.81 to 4.73 t/ha (68.3%).

Microbiocenosis of the Permafrost Soils of Transbaikalia under Agriculture Use

An understanding of how the involvement of soils in agricultural turnover affects soil microbiocenosis has been attained. The aims of this study were to investigate the number of the main groups of microorganisms in microbial complexes, the carbon of microbial biomass and the enzymatic activity in permafrost soils under the influence of tillage. The presented data can provide an insight into the stability of the microbiome in region’s soils under agricultural influence. The significance of the study lies in obtaining new data on the microbiocenosis of permafrost soils, which will make it possible to reveal the orientation and intensity of microbiological processes during their agricultural use. The study uses the classical methods used in soil science and soil microbiology, which are characterized by accuracy and reliability. The general characteristics of the microbiocenosis of different types of the studied region’s soils have been revealed. The quantity of bacteria, including actinomycetes and fungi, in the studied soils was determined. The variability of indicators in time and space is shown. The number of bacteria was revealed to reach its maximum in the autumn period in grey forest non-podzolised soils, and the indicator decreases in the following manner: forest—10.6 billion cells/g, arable land—5.1 billion cells/g, virgin land—2.6 billion cells/g. The lowest indicator of bacterial abundance—0.5 billion cells/g was found on arable permafrost meadow chernozemic soil. A comparatively low bacterial content is characteristic of chernozem meal-carbonated: 1.9 billion cells/g on virgin land and 2.1 billion cells/g on arable land. The length of actinomycete mycelium is dynamic according to the seasons of the year. The maximum length of actinomycete mycelium was observed in grey forest non-podzolised soil (forest) in the autumn period—830 m/g. The maximum length of fungal mycelium was also observed in grey forest non-podzolised soil (forest) in autumn—1200 m/g. In arable variants, the length of fungal mycelium is high in grey forest non-podzolised soils and meadow permafrost soils. In chernozems and permafrost meadow chernozemic soils (virgin and arable) the index is much lower. Assessment of catalase activity showed that the studied soils are poor or moderately enriched in this enzyme. Relatively high invertase activity was found in all variants.

Creation of a green forage chain and haylage making from annual feed crops in Yakutia

The main branch of agriculture in Yakutia is animal husbandry. One of the urgent problems is the provision of livestock with feed. The basis for increasing the productivity of dairy cattle breeding is succulent and green feed. The main raw material for succulent and vitamin feed in Yakutia is the green mass of annual feed crops. The purpose of the research was to consider the creation of a green forage chain and the production of haylage from annual feed crops in Yakutia. The results of research on the creation of a green forage chain and the production of haylage from annual feed crops have been presented in the article. The research was carried out on the basis of the feed production laboratory of the Yakut Scientific and Research Institute of Agriculture in 2019–2021. Data on the yield, nutritional value of annual feed crops for the production of haylage and the creation of the green forage chain have been given. In order to obtain nutritionally balanced feed, the optimal species composition of mixed crops for the green forage chain and haylage was determined, optimal sowing dates and the mode of use of annual crops were established. On permafrost meadow-chernozem soils for the production of haylage, it is recommended to cultivate a vetch-oat mixture with a seeding rate of components: vetch 1,2 million pcs./ha + oats 2,5 million pcs./ha, pea-oat mixture with a seeding rate of components: peas 0,8 million pcs./ha and oats 2,5 million pcs./ha of germinating seeds. On the green forage chain, we recommend the vetch-oat mixture (vetch 1,2 million pcs./ha + oats 2,5 million pcs./ha), rapeseed-oat (rapeseed 2,0 million pcs./ha + oats 1,5 million pcs./ha). Obtaining raw materials for the production of haylage from annual feed crops gave an economic effect for 1 rub. of costs 1,42–1,53 rub. of income, and for creating the green forage chain for 1 rub. of costs gave 1,19–1,50 rub. of income, depending on the timing of sowing.

Influence of Tillage Systems on the Content of Organic Matter and Its Structural State

In a long-term stationary experiment on the basis of a 4-pole fruit-bearing crop rotation, the influence of processing methods with different levels of mechanical impact on the soil was studied: dump (plowing to a depth of 20–22 cm), combined (alternating plowing, plane-cutting processing (to a depth of 10–12 cm), without processing) and plane-cutting processing on the content of organic matter and the structural and aggregate composition of meadow-chernozem soil. It was found that a decrease in the intensity and depth of tillage with a combined and flat-cut system increased the humus content by 0.30 and 0.48% in a layer of 0–20 cm in comparison with dump treatment. The tillage system had a significant impact on the layer-by-layer distribution of labile organic matter in the form of mortmass. The largest stocks of mortmass in the arable layer were noted in the variant of the dump tillage system – 8.69 t/ha. On resource-saving backgrounds, a tendency to decrease the stocks of mortmass in the soil by 0.08–0.69 t/ha was revealed. The contribution of agronomically valuable structural units of 0.25–10 mm in size was 43.1–65.4 in layers, and the yield of large lumps and dust was 34.6–56.9% of the soil mass. The best structural condition of the soil is marked when using a dump treatment system. The presence of a close correlation between the stocks of mortmass in the soil layer of 0–20 cm and the content of structural-aggregate fractions with a size of 10–5 mm (r = 0.72 ± 0.11) and 5–3 mm (r = 0.68 ± 0.10) was established.

Характеристика микробиологической активности почв при их избыточном увлажнении

The results of the study of the microbiological activity of sod-podzolic soils of varying degrees of hydromorphicity and meadow-chernozem soils under rice are presented. When they are excessively moistened, there is an increase in the number of oily, acid-reducing, sulfate-reducing bacteria, anaerobic bacteria of the genus Clostridium, a decrease in catalase activity, an increase in the activity of nitrate reductase, as well as an increase in the ratio of mobile forms of Fe:Mn. The number of microorganisms was influenced by the introduction of siderates and NPK. It is proved that the regulation of appropriate farming systems allows optimizing soil fertility levels. The introduction of KNO3, J, Mo, Mn into the soil also had a positive effect on soil fertility. Keywords: SOIL, ANAEROBIOSIS, MICROORGANISMS, OGLENIE, OPTIMIZATION

Effect of Long-Term Use of Fertilizers on Soil-Dwelling Micromycetes of Meadow Chernozem Soil in Wheat Crops

The effect of long-term systematic application of fertilizers on the mycobiota of meadow chernozem soil in a stationary field experiment (Amur region) was studied for the first time. Information about cultivated soil microscopic fungi is given, an annotated list including 26 species is compiled. It was revealed that the application of nitrogen fertilizers (N30) for wheat against the background of long-term use of fertilizers caused an increase in the total number of soil fungi relative to the control variant by an average of 30–68%, whereas with their aftereffect, a less significant increase in the number of mushroom germs was observed (23–29%). The intervals of the optimal content of macronutrients for the active increase of the pool of microscopic fungi in meadow chernozem soil were determined: phosphorus – 50–65, potassium – 195–210, nitrogen – ≥10 mg/kg with optimal soil moisture of 22–24%. The aftereffect of long-term application of fertilizers, especially organo-mineral fertilizers, as well as the application of mineral fertilizers (N30) directly in the year of the study had a positive effect on species diversity, frequency of occurrence and dynamics of the number of fungal germs in the soil. Negative rearrangements of micromycete complexes as a result of prolonged use of mineral fertilizers in the agrocenoses of meadow chernozem soils were not detected, the introduction of nitrogen-phosphorus fertilizers contributed to a significant decrease in the pool of phytopathogenic fungi.