Fungus T. inhamatum F6-2014 was isolated from the black soils of Northern Kazakhstan in stationary experiments with many years of using herbicides. The research was aimed at studying the biodegrading activity of T. inhamatum in relation to a herbicide with the glyphosate active ingredient in...

Abiotic stress factors, including drought and salinity, severely limit crop productivity worldwide. Furthermore, the extensive use of herbicides, such as glyphosate, disrupts beneficial soil microbiota, further impairing crop growth. Plant growth-promoting bacteria (PGPB) represent a sustainable and efficient strategy to enhance crop yields, particularly under unfavorable environmental and soil conditions. In this study, we characterized Paenibacillus sp. JSM-10, newly isolated from glyphosate-exposed agricultural soil, for its stress tolerance and plant growth-promoting potential, including its morphology examined using complementary microscopy techniques. The strain tolerated up to 0.5 g/L glyphosate, 15 g/L NaCl, and 100 g/L polyethylene glycol (PEG-6000) without significant growth inhibition (p > 0.05), demonstrating robust resilience to such multiple abiotic stresses. Beyond its tolerance, the strain exhibited several beneficial characteristics, including indole-3-acetic acid (IAA) synthesis, siderophore production, and inorganic phosphate solubilization. Furthermore, both living cells and culture filtrates of JSM-10 exhibited a positive trend toward enhancing buckwheat growth under normal and saline conditions, with effect sizes ranging from Hedges’ g = 0.56−0.92. In addition, JSM-10 exhibited antagonistic activity against a range of pathogenic microorganisms, including Nigrospora oryzae, Bipolaris sorokiniana, Alternaria spp., and Escherichia coli. Altogether, these characteristics highlight the Paenibacillus sp. JSM-10 strain and its culture filtrates as promising candidates for application in organic farming aimed at promoting plant growth and improving stress tolerance via plant–microbe interactions.

The study purpose was in vitro investigation of phytotoxic activity of culture broth filtrates (CBFs) of five Alternaria Spp. fungi isolates on development of wheat sprouts. Fungi isolates were received from wheat seeds cultivated under conditions of Northern Kazakhstan. According to the study findings, culture filtrates of all the isolates studied varied with regard to their influence on wheat sprout development. Stimulant effects on seed germinating power were revealed with 14- and 21-day CBFs of A. infectoria (7/4), 14-day CBF of A. brassicae (7/2) and 21-day CBF of A. porri (8/1). It was found that long-term cultivation of fungi on a culture medium contributed to media pH modification towards alkalization due to production of metabolites of various chemical nature, including toxins, which could trigger growth inhibition of radicles and sprouts. However, the CBFs were predominantly low-toxic or non-toxic. Under effect of the 14-day CBF, significant positive correlation was identified between pH values and sprout lengths (0,86±0,25), while negative correlation was found between pH values and germinating power (-0,75±0,33). Change of pH value on the 21st day significantly affected radicle length (-0,92±0,20). Based on the findings it can be concluded that the 14-day CBF of all the Alternaria fungi isolates studied was most toxic for wheat sprouts.

Single-season legume green manuring is widely promoted for soil fertility restoration in degraded agricultural lands, yet its effectiveness in alkaline semi-arid soils remains poorly understood. This study investigated the impact of first-year sweet clover (Melilotus officinalis (L.)) green manuring on soil microbiome structure and agrochemical properties in southern carbonate chernozem soils of Northern Kazakhstan. Using shotgun metagenomics, we analyzed microbial communities from sweet clover-amended soils, clean fallow, and virgin steppe reference sites. Contrary to expectations, sweet clover green manuring did not enhance soil nitrogen availability, with nitrate-N content (9.1 mg/kg) remaining lower than clean fallow (10.5 mg/kg), likely due to temporary immobilization during initial decomposition. While sweet clover significantly increased archaeal diversity (p = 0.01) and enriched nitrogen-cycling taxa, including Nitrospirae and Thaumarchaeota, overall microbial richness remained unchanged (ACE index, p > 0.05). Surprisingly, functional analysis revealed only five significant metabolic differences between sweet clover and fallow systems, indicating functional convergence of agricultural microbiomes regardless of management practice. Correlation analysis identified phosphorus as the master regulator of microbial metabolism (r = 1.0, p < 0.0001), while elevated pH (9.0), K₂O (>1000 mg/kg), and $\mathrm{N}{\mathrm{O}}_3^{-}$ showed strong negative correlations with essential metabolic pathways, revealing previously unrecognized nutrient toxicity thresholds. Virgin steppe maintained 69 unique metabolic pathways lost in agricultural systems, highlighting the ecological cost of cultivation. These findings demonstrate that sweet clover green manuring in alkaline steppe soils induces selective rather than comprehensive microbiome restructuring, with limited immediate benefits for soil fertility. This study provides critical insights for developing sustainable agricultural practices in the world’s extensive semi-arid regions facing similar edaphic constraints.

В статье представлены исследования, проведенные в 2021 году по изучению фитотоксических свойств и супрессивности черноземов южных карбонатных в посевах яровой пшеницы, возделываемой по разным агротехнологиям. В условиях интенсификации земледелия одним из актуальных вопросов является сохранение почвенного плодородия. В связи с этим изучение различных агротехнологий и их влияние на микробиологические показатели почвы при возделывании сельскохозяйственных культур являются практически и теоретически необходимыми. Оценку фитотоксических свойств почвы проводили на проростках яровой мягкой пшеницы (Tríticum aestívum). Установлено, что при определении фитотоксических свойств почвы на варианте пар технологии длина ростков и корней пшеницы была максимальной в сравнение с контрольным вариантом (пар по традиционной технологии). В почве, отобранной под посевами гороха по системе No-Till развитие ростков и корней пшеницы было выше в сравнение с контролем, что свидетельствуют о низкой токсичности этой почвы. Применение нулевой технологии способствует накоплению грибов, таких как Fusarium spр., являющихся фитопатогенными для сельскохозяйственных культур. Результаты исследований супрессивности почвы показали ее увеличение на 47-80% в сравнении с контролем, что объясняет слабую токсичность почвы чернозема южного карбонатного.

Green manure crops and their mixtures are an important component of resource-saving agricultural technologies aimed at increasing soil fertility and improving soil biological conditions. The aim of the study is to assess the impact of legume-cereal, legume-oilseed, and cereal-oilseed green manure mixtures, under different incorporation methods, on soil fertility and health, compared to conventional and chemical fallow. To assess the biological condition of the soil, indicators of the soil microbiota (species and numerical composition of various ecological-trophic groups of microorganisms) were used. This article presents the results of an assessment of the microbial community in fallow fields using various green manure mixtures (peas + oats, oats + mustard, peas + mustard) and different incorporation methods during the 2024–2025 period. It was found that increased activity of soil bacteria was observed in 2024 in the soil under crops of the green manure mixtures peas + oats and peas + mustard. In 2025, a decrease in the amount of ammonia-producing and nitrogen-assimilating microorganisms was observed, accompanied by an increase in the proportion of fungal microflora in separate variants. More stable soil microbiota parameters were observed in the variants with mowing and plowing of the pea-oat mixture. It has been shown that the use of green manure mixtures contributes to the stabilization of the soil’s microbiological condition and the optimization of nitrogen transformation processes under conditions of interannual variability in climatic factors (precipitation and temperature). A comparative analysis was conducted of the effects of green manure mixtures with different botanical compositions and fallow predecessors on soil biological activity and organic matter decomposition processes. The use of green manure mixtures has a positive effect on the development of the soil microbial community compared to fallow and chemical fallow, indicating the potential of this agricultural practice to improve soil biological conditions. The results obtained expand our understanding of the role of green manure mixtures in regulating soil biological processes and can be used in the development of adaptive farming systems (soil-conserving, resource-saving, and biologically oriented).