Search Results (1,535)

Drip irrigation burial depth is a critical management factor for saline-alkali agriculture, yet its mechanisms of influencing crop productivity through soil–microbe–plant interactions remain poorly understood. To explore the regulatory effects of drip irrigation burial depth on the growth and rhizosphere microenvironment of dryland wheat in saline-alkali soil, three treatments (no irrigation control, CK; 5 cm shallow-buried drip irrigation, T5; 25 cm deep-buried drip irrigation, T25) were set up, with soil physicochemical properties, microbial community characteristics, and crop yield analyzed. The results showed that drip irrigation significantly improved soil environment and yield, and T25 exhibited superior comprehensive benefits: soil electrical conductivity was reduced by 63%, organic matter content increased by 44%, and water-salt status was significantly optimized; meanwhile, microbial community structure was altered and root nutrient uptake capacity was enhanced, ultimately achieving a yield of 5347.1 kg ha⁻¹, 55.0% higher than CK. In conclusion, 25 cm deep-buried drip irrigation may provide advantages for wheat cultivation primarily through improved water distribution, desalination, and soil structure enhancement. Full article

The surface chemistry of biochar plays a pivotal role in the adsorption and stabilization of soil organic carbon (SOC); however, sorption-mediated mechanisms remain insufficiently understood for biochars derived from invasive plants. In this study, Solanum rostratum biomass, an aggressive invasive weed in northern China, was pyrolyzed at 400–600 °C in 2023 to produce biochars with varying surface functionalities and structural features. FTIR, Raman, XPS, and SEM analyses revealed that increasing pyrolysis temperature led to decreased oxygen-containing functional groups and enhanced aromatic condensation, reflecting a transition from hydrogen bonding to π–π and hydrophobic sorption mechanisms. Soil incubation experiments using sandy loam soil showed that biochar produced at 500 °C significantly increased the stable carbon pool (SCP) to 52.4%, compared to 30.6% in unamended soils. It also reduced cumulative CO₂ release from 1.74 mg g⁻¹ to 1.21 mg g⁻¹ soil, indicating improved carbon retention. Bacterial 16S rRNA gene sequencing revealed that biochar amendments significantly altered community composition and increased deterministic assembly, particularly under 500 °C biochar, suggesting a sorption-driven niche filtering effect. These findings demonstrate that S. rostratum-derived biochar, especially at intermediate pyrolysis temperatures, enhances both carbon sequestration and microbial habitat structure. This has direct implications for improving degraded soils in arid farming regions, offering a dual strategy for invasive biomass management and climate-resilient agriculture. Full article

To address the challenges of low land use efficiency, soil degradation, and high management costs in Ilex asprella cultivation, this study established an I. asprella–Grona styracifolia intercropping system and systematically evaluated its effects on soil nutrient cycling, microbial communities, and crop growth. Field experiments were conducted in Yunfu City, Guangdong Province, with monoculture (LCK for I. asprella, DCK for G. styracifolia) and three intercropping densities (HDT, LDT, MDT). Combining 16S rRNA sequencing and metagenomics, we analyzed the functional profile of the rhizosphere microbiome. The results showed that intercropping significantly increased the biomass of G. styracifolia, with the medium-density (MDT) treatment increasing plant length and fresh weight by 41.2% and 2.4 times, respectively, compared to monoculture. However, high-density intercropping suppressed the accumulation of medicinal compounds. In terms of soil properties, intercropping significantly enhanced soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), and available nitrogen (AN) in the rhizosphere of both plants. Specifically, AN in the I. asprella rhizosphere increased by 18.9%. Soil urease and acid phosphatase activities were also elevated, while pH decreased. Microbial analysis revealed that intercropping reshaped the rhizosphere microbial community structure, significantly increased the Shannon diversity index of bacteria in the G. styracifolia rhizosphere, and enhanced the complexity of the microbial co-occurrence network. Metagenomic analysis further confirmed that intercropping enriched functional genes related to carbon fixation, nitrogen cycling (nitrogen fixation, assimilatory nitrate reduction), and organic phosphorus mineralization (the phoD gene), thereby driving the transformation and availability of soil nutrients. These findings demonstrate that the I. asprella–G. styracifolia intercropping system, particularly at medium density, effectively improves soil fertility and land use efficiency by regulating rhizosphere microbial functions, providing a theoretical basis for the sustainable ecological cultivation of I. asprella. Full article

Both organic matter and iron oxide (FeO) dynamics pose key roles in soil cadmium (Cd) bioavailability. However, the microbially driven transformation of soil organic matter and FeO and their linkages to Cd fractions remain unclear under reductive soil disinfestation (RSD) with different organic sources, which limits our mechanistic understanding of Cd immobilization by RSD. To address this gap, we conducted a 45 day microcosm experiment using a paddy soil contaminated with 22.8 mg/kg Cd. Six treatments were established: untreated control (CK), waterlogged (WF), and RSD-amended soils with 0.7% or 2.1% wheat straw (LWD, HWD) or soybean meal (LSD, HSD). We systematically assessed soil Cd fractionation, organic carbon and FeO concentrations, and bacterial community structure, aiming to clarify differences in Cd immobilization efficiency and the underlying mechanisms between wheat straw and soybean meal. For strongly extractable Cd, wheat straw RSD reduced the soil Cd concentrations from 6.02 mg/kg to 4.32 mg/kg (28.2%), whereas soybean meal RSD achieved a maximum reduction to 2.26 mg/kg (62.5%). Additionally, the soil mobility factor of Cd decreased from 44.6% (CK) to 39.2% (HWD) and 32.5% (HSD), while the distribution index increased from 58.5% (CK) to 62.2% (HWD) and 66.8% (HSD). Notably, the HWD treatment increased soil total organic carbon, humus, and humic acid concentrations by 34.8%, 24.6%, and 28.3%, respectively. Regarding amorphous FeO, their concentrations increased by 19.1% and 33.3% relative to CK. RSD treatments significantly altered soil C/N ratios (5.91–12.5). The higher C/N ratios associated with wheat straw stimulated r-strategist bacteria (e.g., Firmicutes, Bacteroidetes), which promoted carbohydrate degradation and fermentation, thereby enhancing the accumulation of humic substances. In contrast, the lower C/N ratios of soybean meal increased dissolved organic carbon and activated iron-reducing bacteria (FeRB; e.g., Anaeromyxobacter, Clostridium), driving iron reduction and amorphous iron oxide formation. PLS-PM analysis confirmed that wheat straw RSD immobilized Cd primarily through humification, whereas soybean meal RSD relied on FeRB-mediated FeO amorphization. These findings suggest that Cd immobilization in soil under RSD may be regulated by microbially mediated organic matter transformation and iron oxide dynamics, which was affected by organic materials of different C/N ratios. Full article

This study investigated the effects of different additives on the fermentation quality and bacterial community of silage prepared from Giant Juncao grass (Cenchrus fungigraminus) grown in saline–alkali soil. Four treatments were compared: a control group (CK), wheat bran (WB), fermented Juncao grass juice (FJGJ), and a combined wheat bran + fermented Juncao grass juice treatment (WB + FJGJ). Dynamic changes in physicochemical characteristics—including dry matter (DM), pH, lactic acid (LA), acetic acid (AA), propionic acid (PA), and total volatile fatty acids (TVFA)—were monitored together with shifts in bacterial community structure. Quantitative results showed that FJGJ and WB + FJGJ significantly improved fermentation performance. Compared with the control, the WB + FJGJ treatment reduced the final pH to 3.61 (p < 0.05) and increased lactic acid concentration to 48 g/kg DM. Concentrations of acetic acid and TVFA were also higher in additive-treated silages than in the control. Redundancy analysis indicated that pH and lactic acid were the main environmental factors associated with changes in bacterial community composition, whereas ether extract and acetic acid showed weaker but detectable effects. Bacterial community profiling revealed that genera such as Secundilactobacillus and Lacticaseibacillus dominated in the additive-treated groups, and that the additives significantly altered microbial community structure compared with the control. Overall, the combined application of wheat bran and fermented Juncao grass juice improved the fermentation quality of Giant Juncao grass silage grown on saline–alkali soil and promoted a bacterial community dominated by beneficial lactic acid–producing taxa. Full article

The Sanjiang Plain hosts the largest freshwater wetland in Northeastern China and plays a critical role in regional climate stability. However, climate change and human activities have degraded the wetland, forming a successional gradient from the original flooded wetland to dry shrub and forest vegetation with a lower ground water level. This degradation has altered soil microbial structure and functions, reducing ecological and socio-economic benefits. Along this successional gradient, we used Biolog-ECO plates combined with soil enzyme assays (catalase, urease, sucrase, and acid phosphatase) to assess the dynamics of microbial carbon metabolic activity, measured by average well color development (AWCD). The results showed a systematic decline in AWCD values with advancing succession, revealing a pronounced reduction in overall microbial metabolic activity during wetland degradation. This trend correlated with loss of soil moisture, organic carbon, and nitrogen nutrients. Microbial communities in early successional wetland stages (i.e., original natural wetland and wetland edge) preferred labile carbon sources (e.g., carbohydrates, amino acids), while forested stages favored relatively more structural (e.g., polymers, phenolic compounds). These findings indicate that vegetation succession regulates microbial carbon metabolism by modifying soil physicochemical properties, providing insights for wetland restoration. Full article

Sorghum (Sorghum bicolor L. Moench) is a major cereal crop cultivated in semi-arid regions, but its yield is often constrained by soilborne fungal pathogens that affect plant growth and grain quality. This study explored how Trichoderma-based bioinoculants restructure the structure and functional composition of fungal communities in distinct sorghum compartments (soil, root, seed, and stem) using ITS amplicon sequencing. Two cultivars, Kalatur and Foehn, were evaluated under control and inoculated conditions. Alpha diversity indices revealed that inoculation reduced overall fungal richness and evenness, particularly in seed and stem tissues, while selectively enhancing beneficial taxa. Beta diversity analyses (PERMANOVA, p < 0.01) confirmed significant treatment-driven shifts in community composition. LEfSe analysis identified Trichoderma and Mortierella as biomarkers of inoculated samples, whereas Fusarium, Alternaria, and Penicillium predominated in controls. The enrichment of saprotrophic and symbiotrophic taxa in treated samples, coupled with the decline of pathogenic genera, indicates a transition toward functionally beneficial microbial assemblages. These results demonstrate that Trichoderma bioinoculants not only suppress fungal pathogens but also promote the establishment of beneficial ecological groups contributing to plant and soil health. The present work provides insight into the mechanisms through which microbial inoculants modulate host-associated fungal communities, supporting their use as sustainable tools for crop protection and microbiome management in sorghum-based agroecosystems. Full article

Scutellaria baicalensis is an important medicinal plant, and the diversity of its rhizosphere microbiota may influence its growth, development, and yield. Numerous studies have reported that warming associated with global climate change significantly altered plant-associated soil microbial diversity. To reveal the effects of night-time warming on the rhizosphere microbial community of S. baicalensis, soil microbial diversity in the rhizosphere (RS) and bulk soil (BS) of S. baicalensis were analyzed by employing bacterial 16S rRNA and fungal ITS sequencing technology. Warming significantly altered both bacterial and fungal communities in the rhizosphere and bulk soils of S. baicalensis, with pronounced changes in OTU composition, relative abundances at both phylum and species levels. The analysis of alpha and beta diversity showed that warming significantly altered the fungal community structure in the rhizosphere soil (R² = 0.423, p < 0.05) and significantly reduced the species richness in the bulk soil of S. baicalensis (Shannon and Simpson index, p < 0.05). LEfSe and functional prediction analyses revealed that warming altered the taxonomic composition of both bacterial (35 taxa, LDA > 3) and fungal (24 taxa, LDA > 4) communities in rhizosphere and bulk soils of S. baicalensis, with multiple bacterial and fungal taxa serving as treatment-specific biomarkers. Functional predictions indicated that fungal functional groups, including saprotrophic and mycorrhizal guilds, were more strongly affected by warming than bacteria. Overall, warming has a significantly stronger impact on fungal communities in the rhizosphere and bulk soils of S. baicalensis than on bacteria, and has a significantly greater effect on the diversity of microbial communities in bulk soils than that in rhizosphere soils. This study provides important data for understanding the impact of global climate change on the rhizosphere microbial communities of cultivated plants. Full article

To investigate the effects of different Trichosanthes kirilowii Maxim. varieties on leaf nutrients, soil nutrients, and microbial community composition, this study selected Yuelou No. 3 and Huiji No. 2, two major cultivars from the primary production area of Shishou City. The two varieties were cultivated at different locations under standardized agronomic management practices, and a systematic comparative analysis was carried out over a 10-month sampling period from March to December 2024. The analysis encompassed their leaf nutrients (total nitrogen, total phosphorus, total potassium, and relative chlorophyll content), soil nutrients (organic matter, alkali-hydrolyzable nitrogen, available phosphorus, and available potassium), and microbial community characteristics. The results revealed significant varietal differences in leaf nutrient content: the average total phosphorus content of Yuelou No. 3 (0.44%) was higher than that of Huiji No. 2 (0.39%), while Huiji No. 2 exhibited higher total nitrogen (3.73%), total potassium (3.86%), and SPAD (44.72). Leaf nutrient content in both varieties followed a pattern of nitrogen > potassium > phosphorus, with peak phosphorus and potassium demand occurring earlier in Yuelou No. 3. Additionally, Yuelou No. 3 contained higher organic matter (12.73 g/kg) and alkali-hydrolyzable nitrogen (103.02 mg/kg), while Huiji No. 2 showed enhanced soil pH (7.02), available phosphorus (6.96 mg/kg), and available potassium (180.00 mg/kg). Soil available nutrient dynamics displayed a pattern of slow change during the early stage, a rapid increase during the middle stage, and stabilization in the later stage. Microbial analysis revealed no significant differences in alpha diversity between the two varieties, although Yuelou No. 3 showed marginally higher diversity indices during early to mid-growth stages. In contrast, beta diversity showed significant separation in PCoA space. Proteobacteria, Acidobacteria, and Ascomycota were the dominant microbial phyla. Dominant genera included Kaistobacter, Mortierella, and Neocosmospora, among others, with variety-specific relative abundances. Redundancy analysis further supported the variety-specific influence of soil physicochemical properties on microbial community structure, with available phosphorus, available potassium, and alkali-hydrolyzable nitrogen identified as key factors shaping community composition. This study provides a theoretical basis for understanding the impact of different Trichosanthes kirilowii Maxim. varieties on soil–plant–microbe interactions and suggests potential directions for future research on fertilization and management strategies tailored to varietal differences. Full article

This study explored the patterns and mechanisms influencing changes in silage quality, mycotoxin accumulation, and microbial community structure in oat silage after lodging. Upright oat forage (control, CK), lodging oat forage (upper layer (UL), lower layer (LL), and mixed layers (MLs) were harvested at 0, 7, 25, and 45 days after lodging and ensiled for 60 days. The results showed that the dry matter (DM) and water-soluble carbohydrate (WSC) content decreased significantly (p < 0.05), whereas crude protein (CP) and fiber content increased significantly compared to upright oats (p < 0.05). The WSC and CP content in silage decreased with increasing lodging duration. The fiber content increased in late harvest after lodging. The risk of mycotoxin infection increased after lodging, with aflatoxin levels exceeding EU limits. The mycotoxins in UL silage were the lowest when lodging lasted for seven days. Lodging oat silage was dominated by Lactobacillus, and the Pseudomonas in the lodging group was less than 4%. The fungi in lodging oat silage was lower, and the UL (upper layer) treatment was the lowest when lodging for 7 days. Overall, the transfer of microorganisms, especially Plectosphaerella, Fusarium, Alternaria, Cladosporium, and Botryotrichum, from soil to silage following oat collapse is of interest. The results suggest the soil–plant microbial interactions and their effects on silage fermentation and mycotoxins in lodging oats. Full article

Heavy metal pollution poses a serious threat to soil ecosystems worldwide, as long-term exposure can alter microbial community functioning and reduce overall ecosystem resilience. This study investigated the impact of heavy metal contamination in technogenic industrial areas of the East Kazakhstan Region on soil microbial communities. Soil samples were collected for chemical and metagenomic analyses. Concentrations of Zn, Pb, Cu, and Cd were quantified by flame atomic absorption spectrometry (FAAS). Using long-read whole-metagenome nanopore sequencing, we conducted strain-level profiling of soils with different levels of metal contamination. This approach provided high-resolution taxonomic data, enabling detailed characterization of microbial community structure. Heavy metal exposure did not significantly reduce microbial diversity or richness but influences the quality of community composition. Metal-resistant taxa dominated contaminated soils. Overall, the results highlight the value of long-read sequencing for resolving strain-level responses to environmental contamination. Full article

Silver nanoparticles (AgNPs) are increasingly applied in agriculture and related technologies due to their antimicrobial properties, yet their interactions with soil-associated organisms and microbial communities remain insufficiently characterized. This study examined the effects of AgNP exposure (10.85 mg/L) on trace element accumulation and gut bacterial communities of the earthworm Eisenia fetida under two substrate conditions (horticultural substrate and compost). High-throughput 16S rRNA gene sequencing revealed substrate-dependent shifts in microbial community structure following AgNP exposure. Several bacterial taxa, including Proteobacteria, Gammaproteobacteria, Bacilli, Streptococcus sp., and Staphylococcus sp., exhibited pronounced numerical declines, indicating sensitivity to AgNPs, whereas Actinobacteria and Bacteroidetes showed comparatively higher relative abundances, suggesting greater tolerance. Compost partially mitigated the inhibitory effects of AgNPs on gut microbiota. Concurrently, AgNP exposure altered trace element accumulation patterns in earthworm tissues, highlighting interactions between silver uptake and elemental homeostasis. Collectively, these findings demonstrate that AgNPs can induce taxon- and substrate-specific responses in earthworm-associated microbial communities and metal accumulation, providing insight into potential ecological consequences of nanoparticle use in agricultural systems. Full article

Sustainable food production for a growing population requires farming practices that reduce chemical inputs while maintaining soil as a living, renewable foundation for productivity. This review synthesizes current advances in understanding how endophytic fungi (EFs) interact with the soil microbiome and contribute to the physicochemical and biological dimensions of soil health in arable ecosystems. We examine evidence showing that EFs enhance plant nutrition through phosphate solubilization, siderophore-mediated micronutrient acquisition, and improved nitrogen use efficiency while also modulating plant hormones and stress-responsive pathways. EFs further increase crop resilience to drought, salinity, and heat; suppress pathogens; and influence key soil properties including aggregation, organic matter turnover, and microbial network stability. Recent integration of multi-omics, metabolomics, and community-level analyses has shifted the field from descriptive surveys toward mechanistic insight, revealing how EFs regulate nutrient cycling and remodel rhizosphere communities toward disease-suppressive and nutrient-efficient states. A central contribution of this review is the linkage of EF-mediated plant functions with soil microbiome dynamics and soil structural processes framed within a translational pipeline encompassing strain selection, formulation, delivery, and field scale monitoring. We also highlight current challenges, including context-dependent performance, competition with native microbiota, and formulation and deployment constraints that limit consistent outcomes under field conditions. By bridging microbial ecology with agronomy, this review positions EFs as biocontrol agents, biofertilizers, and ecosystem engineers with strong potential for resilient, low-input, and climate-adaptive cropping systems. Full article

Root exudates are key mediators of plant–soil–microbe interactions, shaping rhizosphere dynamics and influencing agroecosystem resilience. Comprising diverse primary and secondary metabolites, these compounds are actively secreted through specific transport pathways and are modulated by intrinsic plant traits and environmental conditions. Root exudates serve as chemical signals that recruit and structure microbial communities, facilitating nutrient mobilization, microbial feedbacks, and the regulation of plant growth and stress responses. By modulating soil chemical, physical, and biological properties, exudates contribute to carbon cycling, soil health, and the maintenance of ecosystem services. Moreover, they play multifunctional roles in enhancing plant tolerance to abiotic and biotic stresses, while also mediating interactions with neighboring plants. This review provides a holistic perspective on root exudation, encompassing their mechanisms and drivers, roles in rhizosphere ecology and plant stress adaptation, and methodological advances, while highlighting opportunities to harness these processes for resilient, productive, and sustainable agroecosystems. Full article

Dissolved organic carbon (DOC) represents the most readily available and crucial carbon source for soil microorganisms, influencing their community structure, nutrient cycling, and metabolic functions. However, the interplay between functional genes and the organic components of DOC remains poorly understood. In this study, a 33-year fertilization experiment on black soil was carried out, setting up five fertilization treatments: unfertilized control (CK), nitrogen and potassium (NK), nitrogen, P and potassium (NPK), NPK plus straw (NPKS), and NPK plus manure (NPKM). The variation characteristics of soil DOC composition and carbon-degrading functional gene abundance under different fertilization treatments were systematically analyzed. The study found that applying chemical fertilizers combined with organic materials significantly increased soil organic carbon (SOC) and DOC contents in the thin-layer black soil of Gongzhuling. The soil DOC in this region is primarily derived from external inputs (Fresh plant-derived materials). Parallel factor analysis identified four fluorescent components: C1 as visible fulvic acid-like substances, C2 as humic acid-like substances, C3 as ultraviolet fulvic acid-like substances, and C4 as long-wavelength humic-like substances. Among these, NPK plus straw significantly enhanced the fluorescence intensity of the humic acid-like component (C2) and the total fluorescence intensity. The fluorescence intensity of the humic acid-like component increased by 36.0–208.9%, and the total fluorescence intensity increased by 23.8–270.9% compared to the CK. Moreover, the study found that the phylum composition of carbon-degrading microorganisms remained stable under different fertilization treatments. However, NPK plus straw significantly reduced the total abundance of carbon-degrading genes and influenced the composition and transformation of DOC by regulating the expression of key carbon-degrading genes ICL and abfA. These results offer new insights into the mechanisms by which fertilizer management affects the composition and stability of DOC in black soils via microbial functional gene pathways. Full article