The effect of culture medium of Interfillum terricola (J.B.Petersen) Mikhailyuk et al. (Charophyta) on allelopathic, microbiological, agrophysical and agrochemical characteristics of soil

The influence of the cultural medium of the charophyte Interfillum terricola on the allelopathic, microbiological, agrophysical and agrochemical properties of the soil have been studied in model pot experiments. Allelopathic soil regime was assessed by biological testing methods for water-soluble compounds and direct biotesting, as well as by vital indicators of plants-phytometers of winter wheat (Triticum aestivum L., variety "Smuglyanka") and fodder corn (Zea mays L., variety "Kadr 267 MB"). The seeds were sown immediately after the introduction of the culture fluid. The number of germinated seeds was recorded from the 2nd to the 8th day after sowing. The vital condition of phytometer plants was evaluated at the end of the experiments by morphometric indicators of growth (leaf surface area, dry matter biomass of aboveground parts and roots) and the content of photosynthetic pigments in the leaves. When the experiment was completed, soil samples were taken to determine the cytostatic effect of water-soluble compounds and to carry out microbiological and biochemical analyzes. Phenolic compounds were isolated from the soil by ion exchange (desorption) using an ion exchanger KU-2-8 (Н+). In parallel, the electrical conductivity, redox potential, pH and content of nutrients in the soil were determined. The stimulating effect of cultural medium on seed germination, growth and development of assimilation organs of wheat and corn plants has been revealed. The strength of the effect did not depend on the concentration of growing medium, which is characteristic of signal allelopathically active substances. Allelopathic and cytostatic activity of the soil decreased with the use of Interfillum terricola growing medium. The introduction of the cultural fluid significantly affected the number of microorganisms of different ecological and trophic groups. The lowest number of microorganisms was observed at the minimum rate of introduction of microalga medium, and its increase contributed to the growth of the number of almost all studied groups of microorganisms, indicators of transformation and mineralization of organic matter. Under the influence of the cultural medium, the content of phenolic compounds in the soil decreased by 1.1–1.6 times, especially at the norm of 10 mL. The soil treated with cultural fluid had higher rates of transformation and mineralization of organic matter than untreated. The concentration of phenolic compounds in the soil decreased, apparently, due to the activation of the microbiota resulting in the intensification of the destruction processes. An increase in the electrical conductivity of the soil with the introduction of microalgae inoculum was recorded, which may indicate the release of metal ions into the substrate. This confirms the increase in Ca and Mg.

Effect of Peatland Siltation on Total and Labile C, N, P and K

Large areas of peatlands, in addition to the effect of drainage, were subjected to erosional process and were silted. The objective of the study was to verify whether siltation of peatlands hampers mineralization of remaining peat and alters labile C, N, P and K. Total C and N were measured on a CN analyzer, and total P and K on an ICP spectrometer after microwave digestion. The labile fractions of C, N, P and K were extracted with hot water and measured on the CN analyzer and ICP spectrometer. We noted that labile C, N, P and K concentrations in silted topsoil were lower than the values reported in unsilted topsoil. Higher concentration of labile compounds in peats is a signal of higher biological activity and mineralization of organic matter. A TOC/TP < 300 and TOC/TN of approximately 8 in topsoil suggested diminished mineralization and supported our hypothesis that siltation hampered mineralization of organic matter. The TOC/TK ratio proved to be a fine indicator of the state of organic soils siltation, which enabled the separation of unsilted peats from silted topsoil (on the base of value of 177). It can be assumed that the mineralization of peat layers is hampered by the above lying silted topsoil, which is less biologically active, having less oxygen, and therefore conserving underlying peats against oxidation.

Effect of Soil Probiotic on Water Quality and Soil Quality Maintenance and Growth of Freshwater Fish Pangasius hypophthalmus

In recent decades, various procedures have been introduced to improve the conditions of the cultural ponds' conditions in aquaculture. Numerous biological products, including live bacterial inocula, preparation of enzymes, extracts of plant products, and many others, are being promoted to induce water and soil quality conditioners in aquaculture ponds. However, several studies have shown no significant effect of bacterial inoculums, and also the treatment with enzymatic preparation led to an enhancement of microbial mineralization of organic matter, but no effective net production of fish was observed. Probiotics have recently been applied to aquaculture. Probiotics are the live cells or a substrate that induce its benefits by stimulating growth, digestion, and active immune response. Probiotics can also improve water and soil quality. The current study summarizes the role of commercial probiotic ‘Super-PS’ on water quality and soil quality maintenance during the culture of freshwater fish Pangasius hypophthalmus fingerlings.

Microbiological Activity during Co-Composting of Food and Agricultural Waste for Soil Amendment

This study aims to establish the relationship between ambient parameters and the diversity, composition, and function of microbial communities that predominate at each stage of the co-composting of food and agricultural waste. Culture-based and culture-independent methods were used to investigate the changes in the microbiota. The favorable conditions of high initial humidity and C/N ratio caused a decrease in the richness and biodiversity of the microbiota when such conditions existed. During the thermophilic stage, the total microbial number increased, and active mineralization of organic matter was carried out by members of the genera Bacillus, Caldibacillus, Aspergillus, and Penicillium. The fungal community was sensitive to drastic temperature changes. Byssochlamys dominated among fungi during the transition from the mesophilic to the thermophilic stage and during cooling. The biodiversity increased with time and was associated with the dynamics of germination and nitrification indices, so that the more diverse the microbial community, the higher the properties of compost that stimulate plant growth and development. The microbial community of the mature compost, together with mineral plant nutrients ready for consumption and humic compounds, make this compost a good soil additive.

CHANGE OF AGROCHEMICAL INDICATORS OF MEADOW-GLEY SOILS UNDER THE INFLUENCE OF DRYING RECLAMATION (ON THE EXAMPLE OF THE JEWISH AUTONOMOUS REGION)

Целью исследования являлось анализ изменения агрохимических свойств сельскохозяйственных лугово-глеевых почв под влиянием осушительной мелиорации. Для изучения влияния осушительной мелиорации на состояние почв на территории Среднеамурской низменности полевые исследования проводились в 2008 и через десять лент в 2018 гг. Проведение осушительной мелиорации на тяжелых лугово-глеевых почвах Среднеамурской низменности (на примере Еврейской автономной области) сопровождается изменением рН в нейтральную сторону и небольшим увеличением валового содержания металлов, поглощенных оснований и степени насыщенности основаниями. Снижение содержания гумуса связано с усилением аэрации при ежегодной распашке земель, сменой водного режима на застойно-промывной, что способствует быстрой сработке гумуса. Длительное осушение почв приводит не к усилению минерализации органического вещества, а к качественному изменению его состава, что выражается в повышении в пахотном слое отношения содержания углерода гуминовых кислот к содержанию углерода фульвокислот. The aim of the study was to clarify and clarify the nature and degree of change in the basic properties of agricultural meadow-gley soils under the influence of drainage reclamation. To study the effect of drainage reclamation on the state of soils in the territory of the Central Amur Lowland, field studies were conducted in 2008 and through ten tapes in 2018. Conducting drainage reclamation on heavy meadow-gley soils of the Middle Amur Lowland (for example, the Jewish Autonomous Region) is accompanied by a change in pH to the neutral side and a slight increase in the gross content of metals, absorbed bases and degree of saturation with bases. The decrease in humus content is associated with increased aeration during the annual plowing of land, a change in the water regime to stagnant-flushing, which contributes to the rapid depletion of humus. Prolonged drainage of soils does not lead to increased mineralization of organic matter, but to a qualitative change in its composition, which is reflected in an increase in the ratio of the carbon content of humic acids to the carbon content of fulvic acids in the arable layer.

Efficient activity of soil depending on of precursors and major treatment of soil when cultivating winter wheat

The article presents data on the change in the enzymatic activity of the soil in winter wheat crops under the influence of the methods and techniques of tillage and the previous crop in the Central Ciscaucasus zone. The studies were carried out in the zone of the Central Ciscaucasia on the basis of the experimental station of Stavropol State Agrarian University. The determination of the activity of invertase shows that its maximum values are in the variants of the combined treatment, which is associated with more favorable hydrothermal conditions of the arable layer of the soil. Thus, according to its predecessor, pea + oats for green fodder, invertase activity is 27.9 mg of glucose per 1 g of soil for 40 hours, which is almost twice as high in comparison with surface treatment and three times with plowing. The decrease in the activity of invertase during dump processing indicates a rapid rate of mineralization of organic matter. Catalase activity on the studied precursors: on peas with oats for green fodder 1.6 and 1.3; 1.5 and 1.8 peas; for corn silage 1.5 and 1.4 ml 0.1 n. KMnO4 per 1 g of soil for 20 minutes. Revealed a decrease in activity under the influence of plowing, as urease enters the soil with plant debris. When dumping treatment due to movement of plant residues in the underlying layers, the activity of this enzyme decreases to 0.8–0.9 mg of N-NH4 per 10 g of soil for 4 hours, whereas with surface treatment, depending on its predecessor, it is 0.8–– 1.3 mg of N-NH4 / 10 g of soil for 4 hours, with a combination of 1.0–1.1, and for shallow soil, 1.1–1.2 mg of N-NH4 / 10 g of soil in 4 hours.

Microbiological assessment of meadow-chernozem carbonated soil with different fertilization systems

Microorganisms play an important role in the formation of soil fertility, ensure their functioning as biological bodies of nature and are an indicator of qualitative soil changes. Due to the effect of anthropogenic activity on the soil there is a decrease in the number and depletion of the species composition of the microbiota. The aim of the research was to estimate the number of different physiological groups of microorganisms on meadow-chernozem carbonate soil under different fertilizer systems. Determination of the number of different groups of soil microorganisms was carried out according to the method of Zvyagintsev by sowing the soil suspension on solid nutrient media. It was established that the most favorable indicators of microbiocenosis and the highest yield of peas of Tsarevich variety were formed by the aftereffects of organic fertilizers and N45P45K45. The variant without fertilizers causes the development of mineralization of organic matter in meadow-chernozem carbonate soil by the content of pedotrophic and humatizing organisms and formed the lowest yield of peas. Application of only mineral fertilizers for growing peas formed a high rate of accumulation of humus at the level of Kak. = 1,6-1,9.