Meadow Soil Research Articles

Influence of Chemical Meliorants on Microbiological Activity of Chernozem-Meadow Soils

The study was conducted in the Voronezh FASC “Kamennaya Steppe” in 2020–2022. The assessment of the state of the structure of microbial cenosis in meadow soils with the use of various chemical meliorants is given. Options for reclamation included the introduction of gypsum and defecate at a dose of 5 t/ha and a combination of their half doses. The number of ecological and trophic groups of microorganisms was determined by seeding on solid nutrient media. Accounting for organisms assimilating organic forms of nitrogen – by sowing on meat-peptone agar (MPA), accounting for organisms assimilating mineral forms of nitrogen – by sowing on starch-ammonium medium (SAM), accounting for organisms mineralizing humus – by sowing on nitrate agar, accounting for fungi – on Chapek medium, accounting for the amount of nitrogen – on soil plates, accounting for nitrifiers – on hungry agar, accounting for organisms that decompose fiber – on Vinogradsky’s medium. As a result of chemical reclamation of meadow soils with the use of gypsum and defecate as meliorants, patterns of changes in the activity of soil microorganisms were established. It was possible to identify a fairly clear dependence of the increase in the number of microorganisms that utilize organic forms of nitrogen on the use of meliorants in meadow soil of a hollow-shaped depression. Mineralization processes of organic matter were maximally expressed in meadow-chernozem soil on a plain rise when gypsum was used as a meliorant at a dose of 5 t/ha, while the use of gypsum and defecate at a dose of 2.5 + 2.5 t/ha had a greater effect on the content of nitrifiers in this soil. In the chernozem-meadow soil of a hollow-like decrease, the use of defecate at a dose of 5 t/ha led to an increase in the content of actinomycetes. In the chernozem-meadow soil of the plain depression, the use of all meliorants had an impact on the increase in the number of humus mineralizers, fungi, as well as nitrifiers compared with the control. It was not possible to identify any significant pattern associated with the use of meliorants on these soils for the maintenance of azotobacter colonies. In soils with different degrees of soil moisture, the use of meliorants had an ambiguous effect on the number of cellulolytics: an increase in soil hydromorphism in combination with the use of defecate at a dose of 5 t/ha led to a maximum increase in cellular microorganisms in the chernozem-meadow soil of a hollow-like decrease.

ENZYMATIC ACTIVITY OF IRRIGATED MEADOW SOILS OF THE NORTHEASTERN PART OF THE MIRZACHUL OASIS

The article describes the enzymatic activity of the irrigated meadow soils of the north-eastern part of the Mirzachol oasis. Due to weak salinity of irrigated meadow soils, it was found that catalase, peroxidase, and polyphenoloxidase activity of enzymes belonging to the class of oxidases was high. These indicators were also observed in the activity of invertase and urease enzymes. It was observed that the activity of enzymes was high in all studied cuttings in the spring, and decreased in the fall. The activity of enzymes depends on the humus in the soil, the amount of nutrients, the mechanical composition, the amount of different fertilizers used, and the hydrothermal regime of the area.

Reduced soil multifunctionality and microbial network complexity in degraded and revegetated alpine meadows

Understanding how microbial processes develop and change in alpine meadow soils is key to global initiatives toward environmental sustainability and local land management. Yet, how microbial interactions mediate soil multifunctionality in disturbed and managed alpine meadows remains understudied. Here, we investigated multiple community metrics, particularly microbial network properties and assembly processes, of soil bacterial and fungal communities and their links to certain soil functions along a degradation-restoration sequence of alpine meadows in the Qinghai-Tibetan Plateau. Meadow degradation caused significant declines in soil hydraulic conductivity (e.g., higher bulk density, reduced soil porosity and water content) and nitrogen availability, leading to lowered soil multifunctionality. Meadow degradation only caused weak changes in microbial abundance, alpha diversity, and community composition, but remarkably reduced bacterial network complexity, to a less extent for fungal network properties. Short-term artificial restoration with productive grass monocultures did not restore soil multifunctionality, in turn even destabilized bacterial network and favored pathogenic over mutualistic fungi. Soil fungi community are more stable than bacteria in disturbed alpine meadows, and they evolved with distinct assembly strategies (stochastic-dominant versus deterministic-driven processes, respectively). Further, microbial network complexity, positively and better predicts soil multifunctionality than alpha diversity. Our work shows how microbial interaction complexity may enhance soil multifunctionality in degraded alpine meadow ecosystems, noting that meadow restoration with low plant species diversity may failed in restoring multiple ecosystem functions. These findings would help predict the outcomes of global environmental changes and inform management strategies in regional grassland conservation and restoration.

Adsorption of oxytetracycline on subalpine meadow soil from Zoige Plateau, China: Effects of the coexisting Cu2+

Subalpine meadow soil with high moisture and humus content is a unique soil type in the Zoige Plateau. Oxytetracycline and copper are common soil contaminants which interact to form compound pollution. Oxytetracycline's adsorption on natural subalpine meadow soil and its components (humin and the soil without iron and manganese oxides) was studied in the laboratory with and without the presence of Cu2+. The effects of temperature, pH and Cu2+ concentration were documented in batch experiments, allowing deduction of the main sorption mechanisms. The adsorption process had two phases: one rapid, taking place in the first 6 h, and another slower, reaching equilibrium at around 36 h. The adsorption kinetics were pseudo-second-order, and the adsorption isotherm conformed to the Langmuir model at 25 °C. Higher concentrations oxytetracycline increased the adsorption, but higher temperature did not. The presence of Cu2+ had no effect on the equilibrium time, but the amount and rate adsorbed were much greater with Cu2+ concentration increased (except for the soil without iron and manganese oxides). The amounts adsorbed with/without Cu2+ were in the order the humin from subalpine meadow soil (7621 and 7186 μg/g) > the subalpine meadow soil (7298 and 6925 μg/g) > the soil without iron and manganese oxides (7092 and 6862 μg/g), but the difference among those adsorbents was slight. It indicates that humin is a particularly important adsorbent in the subalpine meadow soil. The amount of oxytetracycline adsorbed was greatest at pH 5–9. In addition, Surface complexation through metal bridging was the most important sorption mechanism. Cu2+ and oxytetracycline formed positively-charged complex that was adsorbed and then formed a ternary complex “adsorbent-Cu(II)-oxytetracycline”, in which Cu2+ acted as a bridge. These findings provide a good scientific basis for soil remediation, and for assessing environmental health risks.

Elevated and atmospheric‐level methane consumption by soil methanotrophs of three grasslands in China

AbstractBackgroundMethane (CH4) oxidation driven by soil aerobic methanotrophs demonstrates the capacity of grassland as a CH4 sink.MethodsIn this study, we compared the oxidation characteristics of atmospheric‐level and elevated concentration (10%) CH4 in a typical grassland (steppe) on the Loess Plateau, an alpine meadow (meadow) on the Qinghai‐Tibet Plateau, and an inland arid‐area artificial grassland (pasture) in northwest China and investigated the communities of active methanotrophs and their contribution to CH4 oxidation using DNA‐based stable‐isotope probing and Illumina Miseq sequencing.ResultsThe results showed that the oxidation of atmospheric CH4 only occurred in steppe and meadow soils where the USCγ group of methanotrophs was numerically dominant in the methanotroph community. Pasture soils, with their very low relative abundance of USCγ, did not show atmospheric CH4 oxidation. However, a DNA‐stable isotope probing experiment with 10% CH4 indicated that conventional CH4 oxidizers (Methylocaldum and Methylocystis) rather than USCγ communities assimilated significant amounts of 13CH4 for growth.ConclusionsThe CH4 oxidation mechanisms in the three experimental grassland soils varied significantly. The USCγ group may be obligate oligotrophic microorganisms or their growth requires specific unknown conditions.

Response of methanogenic community and their activity to temperature rise in alpine swamp meadow at different water level of the permafrost wetland on Qinghai-Tibet Plateau.

Wetlands are an important source of atmospheric methane (CH4) and are sensitive to global climate change. Alpine swamp meadows, accounting for ~50% of the natural wetlands on the Qinghai-Tibet Plateau, were considered one of the most important ecosystems. Methanogens are important functional microbes that perform the methane producing process. However, the response of methanogenic community and the main pathways of CH4 production to temperature rise remains unknown in alpine swamp meadow at different water level in permafrost wetlands. In this study, we investigated the response of soil CH4 production and the shift of methanogenic community to temperature rise in the alpine swamp meadow soil samples with different water levels collected from the Qinghai-Tibet Plateau through anaerobic incubation at 5°C, 15°C and 25°C. The results showed that the CH4 contents increased with increasing incubation temperature, and were 5-10 times higher at the high water level sites (GHM1 and GHM2) than that at the low water level site (GHM3). For the high water level sites (GHM1 and GHM2), the change of incubation temperatures had little effect on the methanogenic community structure. Methanotrichaceae (32.44-65.46%), Methanobacteriaceae (19.30-58.86%) and Methanosarcinaceae (3.22-21.24%) were the dominant methanogen groups, with the abundance of Methanotrichaceae and Methanosarcinaceae having a significant positive correlation with CH4 production (p < 0.01). For the low water level site (GHM3), the methanogenic community structure changed greatly at 25°C. The Methanobacteriaceae (59.65-77.33%) was the dominant methanogen group at 5°C and 15°C; In contrast, the Methanosarcinaceae (69.29%) dominated at 25°C, and its abundance showed a significant positive correlation with CH4 production (p < 0.05). Collectively, these findings enhance the understanding of methanogenic community structures and CH4 production in permafrost wetlands with different water levels during the warming process.

Geochemical Controls on the Uranium Cycle in a Lake Watershed

Understanding the uranium (U) cycle─reservoirs and processes─at the watershed scale is key to manage contaminated areas, to elucidate ore formation processes, as well as to implement paleoenvironmental research. Here, we investigated the different steps of the U cycle, from sources to sinks, and the relative roles of redox processes and organic matter in the control of U mobility in the naturally U-rich small mountainous watershed of Lake Nègre (France). We interpret the U repartition in U reservoirs through chemical, isotopic (δ238U and (234U/238U)), and speciation analyses, in light of anterior studies of the site. We show that U(VI) originates from the leaching of U-rich rock fractures and is transported in dissolved forms. Wetlands and meadow soils then act as intermediary sinks where U(VI) is complexed by organic matter (up to >5000 μg/g) and subsequently partly reduced to U(IV). Dissolved U is also supplied to the lake, in addition to particulate and colloidal U resulting from soil physical erosion. After entering the lake, most U(VI)-bearing organic particles settle in the sediments and U(VI) is reduced to U(IV), resulting in high sedimentary U concentrations (up to >1000 μg/g), while a fraction of U is potentially desorbed from particles. Remaining dissolved U is exported from the watershed through the lake outlet stream. In this high-mountain lake catchment, the U cycle is mainly controlled by organic matter complexation and particulate transport, though U reduction in the lake sediments may help its long-term immobilization.

Changes in Fertility of Alluvial Meadow Soil under Different Fertilizer Systems in Vegetable Crop Rotation

In a laboratory and field experiment conducted in the climatic conditions of the Moscow region, it was found that after 2 rotations (6 years) saturated vegetable crop rotation (late white cabbage – carrots – table beets) on alluvial meadow medium loamy soil with annual application of biocompost at a dose of 6 t/ha (total of 18 t/ha), the humus content in the soil stabilized, a tendency to accumulation of alkaline hydrolyzable nitrogen fraction (+6%) was noted and the consumption of mobile forms of phosphorus (–4%) and potassium (–6%), as well as soil decompression. The use of mineral fertilizers in single and one-and-a-half doses revealed a tendency to decrease the content of humus in the soil (by 3–4%), hydrolyzable nitrogen (by 7–8%) and the accumulation of mobile phosphorus (by 1–15%) and potassium (by 3–22%). The introduction of a low dose of mineral fertilizers led to a deterioration of soil fertility, a decrease in the content of humus (–5%), mobile phosphorus and potassium (by 5 and 17%). Slightly more effective was the introduction of biocompost annually at a dose of 3 t/ha. With the joint application of biocompost (6 t/ha) and a single dose of NPK, stabilization of the humus content in the soil at the initial level, accumulation of hydrolyzable nitrogen (by 9%), mobile phosphorus and potassium (by 5–6%) was noted. During 2 rotations, there was a decrease in the content of exchangeable calcium (by 1–10% from the initial level) and magnesium (by 3–11%) and weak acidification of the soil (a decrease in pHKCl by 1–2% from the initial indicator). It was found that the average productivity of arable land without the use of fertilizers was 50 t/ha, increased by 14 when the half dose was applied, by 28 when the single dose was applied, and by 42% when the half dose was applied, the use of biocompost at doses of 3 and 6 t/ha provided an increase in productivity by 8–16%. With the joint annual application of biocompost with a single dose of NPK, the average productivity of crop rotation increased by 26–35%.

Ecosystem Service Relationships, Drivers, and Regulation Strategies in a Degraded Alpine Shrub Meadow on the Northeastern Qinghai-Tibetan Plateau

One of the challenges of managing grasslands sustainably is the conflict between the different ecosystem services they provide. This is especially evident in the Qinghai-Tibetan Plateau (QTP) region, where fragile alpine ecosystems make balancing the needs of grassland conservation and development difficult. However, our current understanding of the relationships and drivers of ecosystem services in degraded alpine shrub meadows on the QTP is insufficient. To address this, we studied forage provisioning and water retention services in a degraded alpine shrub meadow in the northeastern QTP. We analyzed the changes and relationships between these services at different levels of degradation and identified those factors that influenced ecosystem service relationships. The results showed that the forage supply service and the water retention service of the alpine shrub meadow increased and decreased by 23.6% and 27.07%, respectively, due to degradation. The trade-offs between these two services varied depending on the degree of degradation, with light and moderate degradation showing a preference for water retention service, and heavy and extreme degradation showing a preference for forage supply. Water retention was constrained by forage supply and both services showed an exponential function form of decay. The physical and chemical properties of the soil in the alpine shrub meadow remained relatively stable during the degradation process, with only soil organic carbon (SOC), total potassium (TK), and total nitrogen (TN) decreasing significantly. SOC may have indirectly influenced the relationship between the two services by affecting water retention. This study provides insights into alpine shrub meadow management and conservation on the QTP.

Effects of long-term warming on soil prokaryotic communities in shrub and alpine meadows on the eastern edge of the Qinghai-Tibetan Plateau

The variations in response of the soil prokaryote community structure to long-term climate warming among different vegetation types in alpine areas are not fully understood. After an 18-year warming experiment, changes in the diversity and structure of soil prokaryote communities in alpine and shrub meadows of the Tibetan Plateau were analyzed based on 16S rDNA MiSeq sequencing. Proteobacteria (26.70 %), Actinobacteria (20.90 %), and Acidobacteria (13.09 %) were the dominant soil bacterial communities; however, Crenarchaeota (5.69 %) was the dominant archaea at the phylum level. Warming did not significantly affect the top 11 prokaryotic communities in the shrub meadow soil. In meadow soils, however, we found an increase in the relative abundances of Crenarchaeota, Acidobacteria, Chloroflexi, and Planctomycetes and a decrease in the relative abundances of Actinobacteria and Proteobacteria. In terms of alpha-diversity, warming significantly increased the Chao1 and the observed species indices in both the meadow and shrub meadow soils. The soil prokaryote community in the meadow soil was more sensitive to simulated warming than that in the shrub meadow soil. The soil pH and water content were the primary factors that influenced variation in the overall structure and diversity of the soil prokaryotic community. Therefore, the response of soil prokaryote composition and structure (at the phylum level) to long-term warming largely depended on vegetation type, but the response of alpha-diversity was similar among different vegetation types. We conclude that the vegetation type plays a regulatory role in the sensitivity of alpine soil microbial communities to warming.

Disturbance induces similar shifts in arbuscular mycorrhizal fungal communities from grassland and arable field soils.

Anthropogenic disturbances play an increasingly important role in structuring the diversity and functioning of soil organisms such as arbuscular mycorrhizal (AM) fungi. Frequently, multiple land-use practices, which may represent disturbances for AM fungal communities, operate simultaneously in different habitats. It is not known, however, how previous land-use history and specific habitat type influence AM fungal community response to disturbances. We applied mechanical (cutting to stimulate tillage) and chemical (herbicide addition) disturbances to AM fungal communities from meadow and arable field soils. Our results indicated that AM fungal communities from meadows, which previously had experienced mowing, were more species rich than communities from fields that had experienced intensive land-use practices. There were no significant differences, however, in the responses to disturbance of the AM fungal communities from field and meadow soils. We expected mechanical disturbance to promote taxa from the family Glomeraceae which are expected to exhibit a ruderal life-history strategy; instead, the abundance of this family increased in response to chemical disturbance. Simultaneous application of mechanical disturbance and herbicide decreased only the abundance of Diversisporaceae. No AM fungal families increased in abundance when both mechanical and chemical disturbances were applied simultaneously, but all disturbances increased the abundance of culturable AM fungi. Our study demonstrates that although chemical and mechanical forms of disturbance favor different AM fungal families, existing information about family-level characteristics may not adequately characterize the life history strategies of AM fungus species.

SOIL ANALYSIS OF BARN SWALLOW (HIRUNDO RUSTICA) NEST’S (NORTHEASTERN OF ALGERIA)

This work consists of analyzing the Barn Swallows nest’s soil (Hirundo Rustica) which was nested in the northeastern Algeria, particularly in the Mila region (Beinen), the Guelma region (Town-Center and Bouchegouf) and, the Oum El Bouaghi region (Ain el Baida). This species of birds uses different materials to build their nests, whose main component is the existing meadow soil. This study is contributes to knowing the bird strategy on nest building and materials chosen in it. From there, we have done weight chemical analysis according to the Vatan model; the results obtained are represented in the Czerminski diagram; for the organic matter quantification, we have used Walkley and Blacket method, and ecological analysis was according to ANOVA model. The weight chemical analysis results showed us loamy sandstone or marly sandstone soil type on the Northside of the study area (Mila region) and marly sandstone, sandy-marly loams, marl, and marly-sandy limestones on the Southside of the study area (Guelma and Oum El Baouaghi region), the organic matter analysis results showed non-aggressive soils and the ecological analyzes revealed a significant difference between the nest’s compositions of each region except for the loam which has an F = 1.4857 and P = 0.2681. So, the Barn Swallows have a very precise strategy in choosing construction materials for their nests. For that, we recommend to characterize those construction materials by other studies (plasticity, mechanical resistance, mineralogy etc.).

Dynamic evaluation of cropland degradation risk by combining multi-temporal remote sensing and geographical data in the Black Soil Region of Jilin Province, China

Cropland degradation has attracted increasing attention because the important production functions of cropland and its sensitivity to climate change. Based on multi-temporal remote sensing and geographical data, this study developed a comprehensive index of cropland degradation risk (CDRI) using the improved k-means method and applied it to the Black Soil Region of Jilin Province, China, to analyze the changes in cropland degradation risk from 2005 to 2020. The average cropland degradation risk in 2020 was generally higher than that in 2005. Croplands with changes in degradation risk types accounted for 14.27% of the total cropland area, of which croplands showing an increase and decrease in degradation risk accounted for 8.47% and 5.80% of total, respectively. From 2005 to 2020, areas of croplands with a low degradation risk decreased, but those of croplands with a medium degradation risk increased significantly. The synthetic image of bare soil, temperature, precipitation, and soil nutrients contributed greatly to the CDRI. Degradation risk of croplands distributed in black soil, chernozem, and meadow soil fluctuated significantly. The proposed CDRI method comprehensively considers the degree and spatial pattern of cropland degradation risk and has good prospects for the rapid detection of cropland degradation on a large scale.

Mammalian carcass decay increases carbon storage and temporal turnover of carbon-fixing microbes in alpine meadow soil

Corpse decomposition is of great significance to the carbon cycle of natural ecosystem. Carbon fixation is a carbon conversion process that converts carbon dioxide into organic carbon, which greatly contributes to carbon emission reduction. However, the effects of wild animal carcass decay on carbon-fixing microbes in grassland soil environment are still unknown. In this research, thirty wild mammal (Ochotona curzoniae) corpses were placed on alpine meadow soil to study the carbon storage and carbon-fixing microbiota succession for a 94-day decomposition using next-generation sequencing. Our results revealed that 1) the concentration of total carbon increased approximately 2.24–11.22% in the corpse group. 2) Several carbon-fixing bacterial species (Calothrix parietina, Ancylobacter rudongensis, Rhodopseudomonas palustris) may predict the concentration of total carbon. 3) Animal cadaver degradation caused the differentiation of carbon-fixing microbiota structures during succession and made the medium-stage networks of carbon-fixing microbes more complicated. 4) The temporal turnover rate in the experimental groups was higher than that in the control groups, indicating a quick change of gravesoil carbon-fixing microbiota. 5) The deterministic process dominates the assembly mechanism of experimental groups (ranging from 53.42% to 94.94%), which reflects that the carbon-fixing microbial community in gravesoil can be regulated. Under global climate change, this study provides a new perspective for understanding the effects of wild animal carcass decay on soil carbon storage and carbon-fixing microbes.

Insights into the weathering behavior of pyrite in alkaline soil through electrochemical characterizations: Actual hazards or potentially benefits?

Pyrite is the most common metal sulfide mineral in the crust and readily weathers under natural circumstances to release H+ to acidify surrounding groundwater and soil, resulting in heavy metal ions in the surrounding environment (e.g., meadow and saline soils). Meadow and saline soils are two common, widely distributed alkaline soils and can affect pyrite weathering. Currently, the weathering behaviors of pyrite in saline and meadow soil solutions have not been systematically studied. Electrochemistry coupled with surface analysis methods were employed to study pyrite weathering behaviors in simulated saline and meadow soil solutions in this work. Experimental results suggest that saline soil and higher temperatures increase pyrite weathering rates due to the lower resistance and greater capacitance. Surface reactions and diffusion control the weathering kinetics, and the activation energies for the simulated meadow and saline soil solutions are 27.1 and 15.8 kJ mol−1, respectively. In-depth investigations reveal that pyrite is initially oxidized to Fe(OH)3 and S0, and Fe(OH)3 further transforms into goethite γ-FeOOH and hematite α-Fe2O3, while S0 ultimately converts into sulfate. When these iron compounds enter alkaline soils, the alkalinity of soil changes, and iron (hydr)oxides effectively reduce the bioavailability of heavy metals and benefit alkaline soils. Meanwhile, weathering of natural pyrite ores containing toxic elements (such as Cr, As, and Cd) makes these elements bioavailable and potentially degrades the surrounding environment.

Dynamics of the number of microorganisms distributed in irrigated typical soil and grass soils by seasons

Biological preparations developed on the basis of biological methods have been considered the mainstay in the protection and fight against various diseases occurring in plants. It has been proven that the main resource in strengthening the biological condition and fertility of the soil is closely related to the life of saprophytic microorganisms. In this place, microorganisms and microbiological processes in the soil have performed an important task. In particular, it has the characteristic of enriching the soil with biological nitrogen due to the normalization of organic matter in the soil, assimilation of free nitrogen in the air by nitrogen-receiving microorganisms. In the article, it was observed that the amount of microorganisms in the composition of typical irrigated gray and meadow soils changes according to the seasons. It was explained that the highest amount of microorganisms was determined in the spring season, it decreased in the summer season, in autumn, the soil temperature and air temperature increased the amount of microorganisms, and in this season, if the activity of microorganisms is observed in the 0-30 cm layer of the soil, it was observed that it decreases towards the lower layers.

ВЛИЯНИЕ СОРТОВЫХ ОСОБЕННОСТЕЙ НОРМЫ ВЫСЕВА НА ФОРМИРОВАНИЕ ПРОДУКТИВНОСТИ ОВОЩНОЙ ФАСОЛИ

Beans (Phaseolus vulgaris L.) are one of the sources of protein (20-26%), the deficiency of which in the nutrition of mankind is already clearly felt. Standing density and the associated sowing pattern are the most important elements of the technology. The correctly chosen seeding rate, to a large extent, depends on the soil and climatic conditions of the area and the biological characteristics of the varieties. Seeding rate optimization is a top priority. The work purpose. To study the variability of seed productivity, mor-phometric parameters and seed qualities depending on the species and varietal, specifics and growing con-ditions. The objects of research were seed plants, the reproductive sphere and seeds of four varieties of beans. The field experiment was carried out in 2021-2022 on alluvial meadow soils, the experimental site of All-Russian Scientific Research Institute of Vegetable Growing branch of the Federal state budgetary institution located in the Ramenskoye district of the Moscow Region in the floodplain of the Moscow Riv-er. Experimental data have been obtained on the effect of the seeding rate and, accordingly, the density of standing plants on the yield and quality of seeds and beans. The contribution of varietal characteristics and agrotechnical factor to the development of productivity indicators is revealed. New experimental data on optimizing the seeding rate for new bean varieties for this region have been obtained. This made it possible to increase the yield of bean seeds of 3.21 t/ha and 26.71 t/ha of beans, depending on the variety and the density of standing plants. The results of the study are the basis for the selection of varieties, the im-provement of seed production technologies, the development of agricultural practices that contribute to in-creasing the yield of vegetable beans in the conditions of the Moscow region.

Astragalus-cultivated soil was a suitable bed soil for nurturing Angelica sinensis seedlings from the rhizosphere microbiome perspective

Angelica sinensis (Oliv.) Diels is an important Chinese medicinal plant. A. sinensis seedlings are grown on an undisturbed alpine meadow soil to ensure the high-quality seedlings, but these soils are disappearing year after year. Thus, selecting a suitable bed soil for A. sinensis seedlings could ensure their long-term sustainability. Using HiSeq sequencing of 16S and 18S marker genes, we investigated the rhizosphere bacterial and fungal microbiotas of the seedlings grown in wheat, astragalus, potato, and angelica-cultivated soils at a geo-authentic habitat. Co-occurrence network analysis, canonical correspondence analysis, Mantel test, and Envfit test were used to examine the relationship between the microbiotas and the surrounding factors. Astragalus-cultivated soils exhibited the following properties: the highest plant weight, the highest neighborhood connectivity in the bacterial network, the highest ratio of positive/negative relationship in both bacterial and fungal networks, the highest relative abundance of the arbuscular mycorrhizal fungi and the ectomycorrhizal fungi, the lowest relative abundance of Rhizoctonia solani, the suitable soil pH, and the close relationship between the rhizosphere microbiotas and the ecological factors. Moreover, each growth stage has its own major drivers in all crop-cultivated soils. Climate temperature and soil pH at 56 days after planting, precipitation at 98 days, and plant weight as well as microbial biomass C and N at 129 days were the major drivers of the bacterial and fungal microbiotas. Overall, the astragalus-cultivated soil was a suitable bed soil for nurturing A. sinensis seedlings to replace the undisturbed alpine meadow soils.

Effectiveness of the Use of Manure, Biocompost and Siderates for Vegetable Crops

Excessive fascination in vegetable growing with mineral (especially nitrogen) fertilizers has led to significant contamination of soils and products with nitrate, heavy metals, and other toxicants. The scientific literature has accumulated considerable material on the use of various kinds of fertilizers, especially mineral fertilizers. A well-established trend towards the development of organic farming on a global scale requires a more indepth study of the effect of organic fertilizers on vegetable yields and adjustments to previously developed fertilizer systems for vegetable crops. The research was carried out by the Department of Agriculture and Agrochemistry of the All-Russian scientific research institute of vegetable growing-branch of the Federal scientific center of vegetable growing and three experimental stations of the Institute on sod-podzolic, alluvial meadow soils, typical, ordinary and leached chernozems in the Non-chernozem zone, the North Caucasus and Western Siberia. It was found out that the efficiency of the use of cattle manure on average for 6 crops on 6 types of soils was 33% of the increase in yield. The highest increases were found in cucumber (62%) and table beet (54%) crops; cabbage and carrots increased yields by 27 and 22%, respectively, tomato and onion - by an average of 17%. The efficiency of manure was inversely proportional to the amount of humus content in the soil. Studies of the effectiveness of the use of biocomposts based on chicken manure revealed that the biocompost increased the yield of 12 vegetable crops on alluvial meadow soil by an average of 20, mineral fertilizers - by 28%, the joint application of these fertilizers allowed to increase yields by 35%. Green fertilizers (siderates) in the conditions of the Central Processing Plant allowed to increase the yield of vegetables by 8-15%, peas, pea mixture and phacelia turned out to be the most effective, yellow lupin and sunflower were ineffective. In the irrigated conditions of the Rostov region, the complex application of mineral fertilizers, manure and siders increased the yield of vegetable crops from 23.6 to 49.6 t/ha, i.e. by more than 2 times.

Insight into influence of roots on hydrothermal properties of alpine meadow in Tibetan Plateau

The physical and mechanical behavior of alpine meadow in Tibetan Plateau is now attracting widespread attention. In this paper, a series of experiments were conducted to study the influence of roots on hydrothermal behavior of alpine meadow located at Nangqian district, in the east of Tibetan Plateau, China. Root biomass, physical properties and hydrothermal properties were measured at a soil depth of 0–25 cm. The results showed that the root biomass within the depth of 0–15 cm accounts for 86% of the total root biomass. With the increase of soil depth, the root biomass shows a decreasing trend. The hydraulic conductivities and thermal conductivities of alpine meadow soil increase with the decrease of root biomass. There are lower hydraulic conductivity and thermal conductivity of swallow soil (0–5 cm) than that of deep layer soil. For the bottom soil layer, swallow alpine meadow acts as a “cap” and plays a function of ecological barrier of reducing water infiltration and heat transfer. Under the background of global warming, this insight is helpful to understand the relationship between soil hydrothermal properties and natural disasters in Tibetan Plateau.