Search Results (1,070)

Northern corn leaf blight (NCLB), caused by Exserohilum turcicum, is a major foliar disease of maize worldwide. To develop sustainable alternatives that reduce chemical products, we evaluated Bacillus velezensis EM-A8 (GenBank accession number OL704805) as a biocontrol agent under greenhouse and field conditions. The aims of this study were as follows: (i) characterize phytohormone production in two formulations containing the BCA; (ii) assess the influence of the BCA on plant biomass and yield; (iii) compare the efficacy of both formulations in controlling NCLB under field conditions; and (iv) determine whether the treatments affected salicylic acid and phenolic compound levels in maize tissues. The strain synthesized a broad spectrum of phytohormones, including salicylic acid, indoleacetic acid, indolebutyric acid, jasmonic acid, abscisic acid and gibberellic acid, as well as cytokinins such as kinetin, zeatin, and 6-benzylaminopurine. Foliar application increased maize dry biomass by 30%. In field trials, both formulations effectively suppressed NCLB, reducing the number of symptomatic leaves by 25–50% compared with controls. Furthermore, treated plants exhibited yield increases exceeding 1000 kg/ha. These findings demonstrate that B. velezensis EM-A8 provides effective biocontrol of E. turcicum while simultaneously enhancing maize growth and yield under field conditions. Future work should aim to scale up the use of B. velezensis EM-A8 in integrated pest management programs and evaluate its long-term impact on soil microbiota, plant health, and yield sustainability. Full article

Agaricus subrufescens Peck is a nutrient-rich edible fungi with a distinctive flavor, but most varieties are sensitive to cadmium (Cd), making cadmium contamination common during cultivation. Currently, excessive fertilizer uses and increased solid waste are exacerbating cadmium contamination in soils. Since A. subrufescens utilize agricultural residues like straw and livestock manure as cultivation substrates, Cd can be adsorbed readily, leading to secondary accumulation. In this study, the toxic effects of and response mechanisms to different Cd concentrations with respect to mycelial growth, heavy metal accumulation, and antioxidant systems of A. subrufescens were systematically investigated. The results indicated that the mycelia exhibited Cd accumulation capacity, with accumulation levels positively correlated with stress concentration. At a Cd concentration of 5 mg/L, the intracellular Cd concentration in the mycelia reached approximately 800 mg/kg. As the Cd concentration increased, the efficiency of Cd uptake by mycelia correspondingly decreased. Cadmium stress (≥0.5 mg/L) significantly inhibited mycelial growth and induced morphological abnormalities, with the mycelia exhibiting yellowing. Furthermore, Cd induced dose-dependent oxidative stress. Hydrogen peroxide and MDA levels peaked at a Cd concentration of 2 mg/L, reaching 2.26 μmol/g and 8.98 nmol/g, respectively, indicating heightened lipid peroxidation. Low concentrations of Cd (≤2 mg/L) promoted increases in ASA and GSH activity. SOD, POD, GR, and APX activities significantly increased, with the ASA-GSH cycle synergistically scavenging ROS. CAT activity remained persistently inhibited, APX/GR activity was suppressed, and total sugar metabolism was disrupted, leading to the collapse of antioxidant defenses. In summary, depending on the Cd concentration, A. subrufescens mycelia exhibit markedly different responses at low versus high concentrations. This study provides a foundation for further research into the application of edible fungi in heavy metal-resistant cultivation. Full article

Cowpea Fusarium wilt (CFW) is a soilborne fungal disease caused by Fusarium oxysporum f. sp. tracheiphilum (Fot), leading to substantial yield losses globally. This study evaluates the biocontrol potential of Bacillus velezensis HAB-2 and develops a microbial combination for effective disease management. B. velezensis HAB-2 suppressed F. oxysporum f. sp. tracheiphilum AIQBFO93 growth by 69.8% in vitro and exhibited multiple plant growth-promoting traits. Pot experiments demonstrated that HAB-2 alone achieved a 47.62% control rate against CFW. Furthermore, two compatible plant growth-promoting rhizobacteria (PGPR), Pseudomonas hunanensis HD33 and Enterobacter soli HD42, were isolated from the rhizosphere soil of cowpea previously treated with HAB-2. These two strains were combined with HAB-2 at different concentrations in 15 microbial combinations. The combined application of the three strains provided more consistent disease control, with the optimal combination demonstrating a 15.15% higher control rate than HAB-2 alone. Compared to the untreated control, this combination significantly increased cowpea fresh weight, leaf area, and plant height by 10.60%, 8.04%, and 7.81%, respectively, and upregulated the expression of defense-related genes, indicating enhanced resistance. These results confirm that B. velezensis HAB-2 is an effective biocontrol agent against wilt disease, and its synergistic application with functionally complementary PGPR strains provides a viable strategy for sustainable crop disease management. Full article

The increasing prevalence of pests and diseases in agriculture necessitates innovative strategies for crop protection that mitigate environmental impacts. This review paper investigates the synergistic potential of combining microbial biocontrol agents and phytochemical biopesticides as sustainable alternatives to chemical pesticides. Through a comprehensive review of recent literature, we analyze the mechanisms by which beneficial microbes (e.g., Trichoderma, Bacillus, and Pseudomonas) enhance plant resilience and suppress pathogens, and how plant-derived phytochemicals such as essential oils, alkaloids, and flavonoids contribute to pest deterrence and disease resistance. The integration of these bio-based resources forms an actionable framework for sustainable crop protection—enabling reduced chemical dependence, improved soil health, and enhanced biodiversity. Examples of synergistic success, such as the combined use of Bacillus thuringiensis with neem extract and Trichoderma with lemongrass oil, illustrate their field potential. Future research should prioritize the formulation of stable microbial–phytochemical consortia, field validation of synergistic efficacy, and optimization of delivery systems to support commercial-scale adoption. Ultimately, this study promotes a paradigm shift toward eco-efficient pest management, bridging fundamental research and applied innovation for resilient agroecosystems. Full article

Understory vegetation plays a pivotal role in enhancing forest biodiversity, and its restoration is crucial for sustainable forest development, energy flow, and nutrient cycling. However, the dynamics of the biomass, diversity, and species composition of understory vegetation in plantations in south China, along with their key drivers, remain poorly understood. This study investigated four mature plantation types (Pinus massoniana, Pinus caribaea, Cunninghamia lanceolata, and mixed Chinese fir–broadleaf forests) in south China through plot surveys, environmental factor measurements, and structural equation modeling (SEM) to explore the diversity, biomass allocation patterns, and driving mechanisms of understory vegetation. The results demonstrated the following. (1) The introduced Caribbean pine forests exhibited higher shrub biomass than native Masson pine forests, which was driven by their high canopy openness favoring light-demanding species (e.g., Melicope pteleifolia, IV = 33.93%), but their low mingling degree limited herb diversity. (2) Masson pine forests showed superior shrub diversity due to their random spatial distribution and higher soil total potassium (TK) content. (3) Mixed Chinese fir–broadleaf forests achieved 24.50–66.06% higher herb biomass compared to coniferous monocultures, supported by high mingling degree, random spatial configuration, and phosphorus-potassium-enriched soil, with concurrently improved herb diversity. SEM revealed that stand structure (DBH, density, mingling degree) directly drove shrub diversity by regulating light availability, while herb biomass was primarily governed by soil total phosphorus (TP) and pH. Canopy-induced light suppression negatively affected herb diversity. We recommend optimizing stand density and canopy structure through thinning and pruning to enhance light heterogeneity alongside supplementing slow-release P fertilizers in P-deficient stands. This study provides theoretical support for the multi-objective management of south China plantations, emphasizing the synergistic necessity of stand structure optimization and soil amendment. Full article

Sugarcane smut, caused by the fungal pathogen Sporisorium scitamineum, leads to significant economic losses in the global sugarcane industry. Bio-organic fertilizers (BF) offer a promising and sustainable strategy to mitigate smut incidence and enhance sugarcane growth. While the application of BF is known to modulate root exudates and rhizosphere microbial community structure, thereby promoting disease resistance, the precise mechanisms underpinning BF-mediated suppression of sugarcane smut remain largely unclear. This study investigated the microbiological mechanisms of smut suppression using a pot experiment, comparing a novel BF treatment (composted substrate enriched with Bacillus subtilis, Bacillus altitudinis, Bacillus cereus, Trichoderma harzianum, and Trichoderma longibrachiatum, biochar, and calcium carbonate) with a control receiving only conventional organic fertilizer. BF application significantly increased plant height (by 95.2%), dry weight (137.5%), fresh weight (253.3%), and sugar content (43.1%) relative to the control. Furthermore, the BF treatment enhanced catalase activity by 167.8% and peroxidase activity by 102.3% in sugarcane leaves, while the control effectiveness against the incidence of smut disease reached 88.0%. Analysis of the rhizosphere microbiome revealed that BF application significantly altered microbial alpha- and beta-diversity. Specifically, the BF treatment notably enriched beneficial genera such as Pseudomonas and Meyerozyma. Beta-diversity analysis revealed distinct microbial community structures in BF-treated rhizosphere soil compared to the control. Correlation and random forest analyses identified Pseudomonas and Meyerozyma as key taxa that were positively associated with sugarcane growth parameters and negatively correlated with smut incidence. These findings elucidate the dual role of this novel BF in enhancing sugarcane growth and suppressing smut incidence through the strategic reshaping of the rhizosphere microbiome. Full article

The secondary metabolite 2,4-diacetylphloroglucinol (2,4-DAPG), which is produced by Pseudomonas bacteria, is a potent antimicrobial agent with well-documented properties that suppress phytopathogens. However, its broader ecological impact on soil microbial communities is not understood. Through a combination of controlled microcosm and field trials, we have demonstrated that the effects of 2,4-DAPG are highly context-dependent. Laboratory exposure (10 mg kg⁻¹) altered the abundance of 8.53% of bacterial and 6.91% of fungal amplicon sequence variants, and simplified the bacterial co-occurrence networks (reduced number of nodes and links). In contrast, field conditions amplified bacterial sensitivity (the Shannon index decreased from 4.77 to 4.17, p < 0.05) but maintained fungal stability (Shannon index varied from 3.93 to 3.97, p > 0.05); these conditions affected a smaller proportion of fungal ASVs (4.23%). Taxonomic analysis revealed consistent suppression of fungi of the Mucoromycota (e.g., Mortierella) and context-dependent shifts in bacteria, with an enrichment of Bacillota (e.g., Bacillus, Paenibacillus) in the laboratory but not in the field. Enzymatic responses revealed a dose-dependent activation of the C-cycle, with up to 7.4-fold increases in the laboratory and up to a 10.5-fold increase in the field. P- and N- cycles showed more complex dynamics, with acid phosphatase activity increasing 3.8-fold in laboratory conditions and recovering from initial suppression to an increase of 144% in field conditions, while N-acetylglucosaminidase activity increased and L-leucine aminopeptidase decreased under laboratory conditions. Our results suggest that the response of microorganisms to 2,4-DAPG in natural soils is reduced, probably due to functional redundancy and pre-adaptation to abiotic stresses. This difference between laboratory and field studies warns against extrapolating data from controlled experiments to predict outcomes in agricultural ecosystems, and emphasizes the need for a context-specific evaluation of biocontrol agents. Full article

Soil water availability and nitrogen (N) deposition critically influence biogenic volatile organic compound (BVOC) emissions, thereby affecting atmospheric chemistry. However, their differential short- and long-term effects remain unclear. Here, Ormosia pinnata and Pinus massoniana seedlings were exposed to three water regimes (moderate drought, MD; normal irrigation, NI; near-saturated irrigation, NSI) and two nitrogen (N0; 0 kg N ha⁻¹ yr⁻¹; N80; 80 kg N ha⁻¹ yr⁻¹) treatments for 20 months. Branch-level BVOC emissions and leaf physiological and biochemical traits were examined after 8 months (short term) and 16 months (long term). In the short term, P. massoniana predominantly emitted α-pinene, β-pinene, and γ-terpinene, whereas O. pinnata emitted isoprene (ISO). After prolonged exposure, ISO became the dominant in both species. Short-term MD and NSI conditions stimulated ISO emissions in O. pinnata, with N80 addition further amplifying this effect. In contrast, long-term treatments tended to suppress ISO emissions in O. pinnata, particularly under N80. Short-term water treatments had no significant effect on monoterpene (MT) emissions in P. massoniana. Under long-term water treatments, N80 suppressed ISO emissions; nevertheless, ISO emission rates (ISOrate) progressively increased with increasing soil water availability. Although leaf intercellular CO₂ concentration (Ci), stomatal conductance (g_s), and photosynthesis-related enzymes exhibited partial correlations with BVOC emissions, an overall decoupling between leaf traits and emission patterns was evident. Our findings demonstrate the significant changes in both BVOC composition and emission magnitudes under the joint effects of water availability and nitrogen deposition, providing important implications for improving regional air quality modeling and BVOC emission predictions. Full article

Crown gall disease, caused by soil-borne bacterial pathogens, such as Allorhizobium vitis, poses a significant threat to grapevine cultivation in Japan, particularly under environmental conditions exacerbated by climate change. Effective chemical control options are limited, highlighting the need for sustainable biocontrol strategies. In this study, we screened a library of soil bacteria with known antagonistic activity against major grapevine fungal pathogens and identified Pseudomonas sp. strain YU44 as a broad-spectrum antagonist of crown gall pathogens A. vitis and Rhizobium radiobacter. In vitro assays demonstrated that YU44 inhibits the growth of both pathogens by secreting bioactive compounds. In vivo bioassays confirmed that pretreatment with YU44 significantly suppresses crown gall formation in grapevine and rose seedlings. Additionally, YU44 application to soil near the stem base reduces disease severity in grapevine seedlings, supporting its potential as a practical biocontrol agent. Although complete disease suppression is not achieved, YU44 represents a promising environmentally friendly alternative for integrated disease management because it can complement resistant rootstocks, sanitation practices, and cultivation methods. These findings highlight YU44’s potential as an adaptive management tool for crown gall disease in the face of climate change. Full article

Biochar is increasingly recognized as a multifunctional soil amendment that improves soil fertility, nutrient cycling, and crop productivity. Studies across field, greenhouse, and incubation settings show that biochar enhances nutrient retention, reduces leaching, and regulates carbon, nitrogen, and phosphorus cycling. Its effects are shaped by intrinsic physicochemical properties and interactions with soil minerals, microbial communities, and enzymatic processes. Short-term benefits of biochar applications often include improved nutrient adsorption and water regulation, while long-term applications support stable soil organic matter formation, root development, and fertilizer use efficiency. Biochar also reshapes soil microbial diversity and activity. Beneficial bacterial groups such as Proteobacteria and Actinobacteria, along with fungi such as Mortierella, respond positively, enhancing nitrogen fixation, phosphorus solubilization, and organic matter decomposition. Meanwhile, biochar applications could suppress pathogens. Enzyme activities, including urease and phosphatase, are typically stimulated, driving nutrient mobilization. Yet outcomes remain context-dependent, with biochar feedstock, application rate, soil conditions, and crop type influencing results; excessive use may suppress enzymatic activity, reduce nutrient availability, or shift microbial communities unfavorably. Practically, biochar can improve fertilizer efficiency, restore degraded soils, and reduce greenhouse gas emissions, contributing to climate-smart agriculture. Future work should prioritize long-term, multi-site trials and advanced analytical tools to refine sustainable application strategies. Full article

This study establishes a synergistic Texture–Quota–Salinity (T–Q–S) model to optimize soil water–salt dynamics in arid agricultural systems. Key findings reveal a sand content threshold (S₀ = 45.2%) governing salt transport efficiency: (1) Sandy soils (S > 50%) exhibit high leaching capacity, enabling the use of saline water (4 g·L⁻¹) with a 270 mm quota to achieve >75% desalination. (2) Threshold soils (S ≈ 45.2%) balance leaching and retention, maximizing nutrient conservation under brackish water (2 g·L⁻¹) and 260 mm irrigation. (3) Clayey soils (S < 30%) require freshwater (≤2 g·L⁻¹) and reduced quotas (≤230 mm) to mitigate surface salinization. The S₀ threshold enables precise irrigation strategies: deep leaching in sandy soils, balanced management in threshold soils, and salt-suppression in clayey soils, enhancing water efficiency by 25% while controlling root zone salinity. Full article

As a critical ecological barrier in the arid and semi-arid regions of northwestern China, the spatio-temporal evolution of vegetation carbon sequestration in the Hexi Corridor is of great significance to the ecological security of this region. Based on multi-source remote sensing and meteorological data, this study integrated second-order partial correlation analysis, ridge regression, and other methods to reveal the spatio-temporal evolution patterns of Gross Primary Productivity (GPP) in the Hexi Corridor from 2003 to 2022, as well as the response characteristics of GPP to air temperature, precipitation, and Vapor Pressure Deficit (VPD). From 2003 to 2022, GPP in the Hexi Corridor showed an overall increasing trend, the spatial distribution of GPP showed a pattern of being higher in the east and lower in the west. In the central oasis region, intensive irrigation agriculture supported consistently high GPP values with sustained growth. Elevated air temperatures extended the growing season, further promoting GPP growth. Due to irrigation and sufficient soil moisture, the contributions of precipitation and VPD were relatively low. In contrast, desert and high-altitude permafrost areas, constrained by water and heat limitations, exhibited consistently low GPP values, which further declined due to climate fluctuations. In desert regions, high air temperatures intensified evaporation, suppressing GPP, while precipitation and VPD played more significant roles. This study provides a detailed analysis of the spatio-temporal change patterns of GPP in the Hexi Corridor and its response to climatic factors. In the future, the Hexi Corridor needs to adopt dual approaches of natural restoration and precise regulation, coordinate ecological security, food security, and economic development, and provide a scientific paradigm for carbon neutrality and ecological barrier construction in arid areas of Northwest China. Full article

Biochar and organic fertilizer applications are widely recognized as effective strategies for mitigating greenhouse gas emissions and controlling agricultural non-point source pollution in agroecosystems. However, the combined effects of these two approaches on greenhouse gas emissions and agricultural non-point source pollution remain insufficiently understood. Through consecutive field-based positioning plot trials, this study systematically examined the individual and combined effects of biochar and organic fertilizer amendments on N runoff loss (WTN) and gaseous emissions (N₂O and NH₃), N-cycling functional microbial communities, and soil physicochemical properties. Results demonstrated that conventional chemical fertilization resulted in 20.70% total N loss (4.48% gaseous emissions, 15.22% runoff losses). Biochar and organic fertilizer applications significantly reduced WTN losses by 8.06% and 7.43%, respectively, and decreased gaseous losses by 2.01% and 1.88%, while concurrently enhancing plant N uptake and soil residual N. Random forest analysis combined with partial least squares structural equation modeling revealed that soil organic carbon directly modulated nitrogen runoff losses and indirectly influenced aggregate stability and macroaggregate formation. Dissolved organic carbon (DOC) and recalcitrant organic carbon (ROC) exhibited dual regulatory effects on NH₃ volatilization through both direct pathways and indirect mediation via aggregate stability. Notably, biochar and organic fertilizer amendments induced significant compositional shifts in nirS- and nirK-type denitrifying microbial communities. pH, cation exchange capacity (CEC), and iron oxide–carbon complexes (IOCS) were identified as key factors suppressing N₂O emissions through inhibitory effects on Azoarcus and Bosea genera. Our findings demonstrate that biochar and organic fertilizers differentially modulate soil physicochemical properties and denitrifier community structure, with emission reduction disparities attributable to distinct mechanisms’ enhanced aggregate stability and modified denitrification potential through genus-level microbial community restructuring, particularly affecting Azoarcus and Bosea populations. This study offers valuable insights into the regulation of carbon sources for nitrogen management strategies within sustainable acidic soil vegetable production systems. Full article

The increasing frequency of global extreme climate events has heightened the need to understand the mechanisms through which desert ecosystems respond to altered precipitation patterns. This includes elucidating how arbuscular mycorrhizal fungi (AMF) drive these responses by regulating key soil processes and shaping microbial community dynamics. We therefore conducted an in situ experiment involving increased precipitation and AMF suppression, and phospholipid fatty acid (PLFA) was employed to reveal the changes in soil microbial community. Results showed that increased precipitation significantly promoted the growth of soil AMF and Actinobacteria (Act). Increased precipitation significantly changed soil microbial community structure and promoted soil microbial community diversity, but it posed neutral effects on soil microbial community biomass. AMF suppression clearly inhibited AM fungal growth but increased the growth of Act and Gram-positive bacteria (G⁺) and posed limited effects on Gram-negative bacteria (G⁻), leading to an increased G⁺/G⁻ ratio. Notably, AMF suppression posed slight effects on the biomass, diversity, and structure of soil microbial community. Random forest analysis revealed that soil ammonium nitrogen (NH₄⁺-N), microbial biomass nitrogen (MBN), and soil organic carbon (SOC) were the main factors influencing different soil microbes, and soil Act and G⁺ were the main factors influencing plant community diversity, but AMF were the primary factor influencing plant community biomass. More importantly, structural equation modeling (SEM) results further confirmed that increased precipitation and AMF significantly altered plant community diversity by influencing soil AM fungi and increased plant community biomass by promoting soil AM fungal growth. In conclusion, our results demonstrate that increased precipitation enhances plant community productivity and diversity in desert ecosystems primarily by stimulating the growth of arbuscular mycorrhizal fungi, which function as a key biological pathway mediating the ecosystem’s response to climate change. Full article

Plastic mulch is widely used in organic strawberry production but raises sustainability concerns due to its persistence, disposal challenges, and contribution to microplastic pollution. This study evaluated the potential of high-residue cover crops and living mulches as alternatives to plastic mulch in coastal California. Over two seasons (2022–2024), we compared five mulching treatments: black polyethylene mulch (Plastic); a white clover (Trifolium repens) living mulch (Clover); two roller-crimped sorghum–sudangrass and field pea mixtures (Sorghum 1, Sorghum 2); and a roller-crimped buckwheat–pea mixture (Buckwheat). The objectives were to evaluate the effectiveness of these treatments on (i) soil properties and biological indicators, (ii) weed suppression, and (iii) strawberry yield in organic systems. A schematic timeline was developed to depict cover-crop growth, termination, and strawberry production across both years. Compost (10 t·ha⁻¹) and fish emulsion (5–1–1 NPK, 4 L·ha⁻¹ biweekly) were applied to all treatments during fruiting. Sorghum residues produced the highest biomass (up to 23 t·ha⁻¹) and supported yields comparable to plastic mulch in 2023. Under lower-yield conditions in 2024, sorghum-based treatments outperformed plastic. Soil responses were modest and time-point specific: Sorghum 1 showed higher organic C and organic N pre-harvest in 2023, and both sorghum treatments increased soil organic matter pre-harvest in 2024. Biological indicators such as CO₂–C and microbially active carbon declined seasonally across all treatments, indicating strong temporal control. Weed outcomes diverged by system—Clover suppressed weeds effectively but reduced yield by >50% due to competition, while Buckwheat decomposed rapidly and provided limited late-season suppression. These results demonstrate that rolled high-residue cover crops, particularly sorghum-based systems, can reduce dependence on plastic mulch while maintaining yields and enhancing soil cover. Living mulches and short-lived covers may complement residue systems when managed to minimize competition and extend ground cover. Full article