Search Results (1,394)

The Ningxia Yellow River Irrigation District in China has long been influenced by flood irrigation and intensive fertilizer input under its particular geological and climatic constraints, and this region is characterized by low soil organic matter, poor nutrient status, low permeability, high pH, and widespread salinization. This cross-sectional field study compared the soil physicochemical properties and microbial communities among saline–alkali soil (SAS), straw-returning farmland (SR), and traditionally managed farmland (FM). EC was higher in SAS (approximately 4.21 dS·m⁻¹) than in SR and FM (approximately 0.23 and 0.30 dS·m⁻¹, respectively), whereas TOC and C/N were higher in SR (approximately 1.00% and 10.58, respectively) than in FM (approximately 0.78% and 8.69) and SAS (approximately 0.43% and 8.81). Bacterial and fungal communities showed different distribution patterns among the three farmland types. Compared with fungi, bacterial community structure and richness varied more clearly across soils differing in salinity and organic matter status. Variations in microbial community composition were accompanied by differences in soil salinity and carbon- and nitrogen-related properties. Acidobacteriota was positively correlated with soil carbon and nitrogen variables and negatively correlated with pH and EC, while Ascomycota was positively correlated with total carbon (TC) and TOC. These results show that straw-returning farmland differed from saline–alkali soil and traditionally managed farmland in both soil properties and microbial community characteristics, highlighting potential soil–microbe associations in saline-affected agricultural systems. Full article

Hydroponic cultivation is expanding rapidly as a resource-efficient alternative to soil-based farming, but challenges related to nutrient management, abiotic or biotic stresses, and organic production still limit the system’s performance and efficiency. Biostimulants are increasingly being explored as a promising strategy to support productivity and sustainability in soilless systems. This review summarizes the current evidence on the use of plant biostimulants to support crop performance in hydroponic systems. Microbial biostimulants, such as plant growth promoting rhizobacteria, Arbuscular Mycorrhizal Fungi, and Trichoderma spp., have been reported to promote root growth by synthesizing phytohormones, enhance nutrient uptake, and reduce the impacts of salt and heat stress, with reported improvements in biomass and nutrient use efficiency. Seaweed extracts and protein hydrolysates modulate plant hormonal balance, improve antioxidant defense, and have been associated with improvements in yield and quality. Humic and fulvic acids increase micronutrient bioavailability through chelation and stimulate root activity through auxin-like effects. In organic hydroponics, biostimulants may help address the nutrient gap by accelerating organic matter mineralization. Existing key challenges include the lack of hydroponic-specific dosage guidelines and high commercialization costs. Future efforts should further evaluate system-specific strategies, including emerging tools such as artificial intelligence-optimized strategies and the use of clustered regularly interspaced short palindromic repeats-edited microbes to support the long-term sustainability of controlled environment agriculture. Full article

Soil-borne diseases pose a severe threat to global agricultural production and food security. Traditional chemical control methods face significant challenges, including environmental pressure, pathogen resistance, and food safety concerns. The rhizosphere microbial community, often termed the plant’s ‘second genome’, plays a pivotal role in maintaining plant health and defending against pathogen invasion. Recent advances in multi-omics technologies, synthetic microbial communities (SynComs) construction, and rhizosphere metabolomics have significantly advanced our understanding of the mechanisms by which rhizosphere microbiomes suppress soil-borne diseases. This review systematically summarizes the following: 1. key drivers of rhizosphere microbial community assembly, particularly plant “cry for help” signaling; 2. core beneficial microbial taxa and their disease-suppressive mechanisms; 3. the critical role of microbial interaction networks; 4. microbiome-based management strategies and their application progress; and 5. current challenges and future research directions. Compared with previous reviews that separately discussed rhizosphere microbiota, disease-suppressive soils, synthetic microbial communities (SynComs), or prebiotics, this review uniquely integrates multiple levels of regulation, from plant genetic determinants (‘M genes’) and root exudate-mediated ‘crying for help’ to microbiome engineering (SynComs and prebiotics) and cross-kingdom interactions (bacteria–fungi–protists–phages). A central conceptual axis of ‘M genes → microbiome engineering → breeding’ is proposed, bridging plant genetics, microbial ecology, and crop improvement for durable disease suppression. Ultimately, this work aims to provide a theoretical foundation for developing efficient and sustainable green control technologies against soil-borne diseases. Full article

To enhance the benefits and ecological safety of tomato residue retention, this study evaluated the regulatory effects of conventional ambient temperature retention (CR) and solar high-temperature retention (TR) on the initial soil environment and rhizosphere microecology of subsequent crops (continuous tomato and rotational cucumber). The results showed that CR promoted the accumulation of humic acid and increased the contents of phenolic acids and small-molecule organic acids in the soil. TR also increased small-molecule organic acids but primarily enriched fulvic acid, accompanied by higher concentrations of phenolic acids. Regarding microecological responses, CR enriched potential plant-growth-promoting bacteria (Pseudomonas, Sphingomonas, Lysobacter) in the rhizosphere, but it also increased the relative abundance of the potential pathogen Fusarium. In contrast, TR promoted the colonization of heat-tolerant beneficial biocontrol microbes (Bacillus, Chaetomium, Mycothermus), with no Fusarium enrichment observed. Redundancy analysis and Mantel tests revealed that the changes in soil nutrients and organic acid fractions induced by residue retention were correlated with the succession of the rhizosphere microbial community and the reconstruction of the metabolic profile. This study demonstrates that TR can effectively mitigate the risk of pathogen enrichment associated with ambient temperature retention, constructing a potentially disease-suppressive initial microecological environment for subsequent crops. Full article

The salinization of natural grasslands is a growing global concern. The Songnen Plain in northeastern China represents a typical soda–saline grassland region, yet an integrated understanding of how salinization reshapes plant, soil, and microbial components in this ecosystem remains limited. In this study, we investigated plant community characteristics, soil physicochemical properties, and soil microbial communities across a salinity gradient (from non-saline to extremely severe saline) using field surveys, laboratory analyses, and structural equation modeling (SEM). Our results showed that vegetation species diversity, the Shannon–Wiener index, and Simpson’s index all decreased from mild to severe salinization. Soil nutrient indicators, including total nitrogen (TN), total phosphorus (TP), and total potassium (TK), significantly decreased with increasing salinity. SEM revealed that plant community diversity had a significant positive effect on soil microorganisms, whereas soil properties, particularly available potassium (AK) and electrical conductivity (EC), exerted significant negative effects on microbial diversity. Together, these results provide an integrated view of how salinization restructures plant–soil–microbe interactions across the Songnen Plain grasslands. These findings improve understanding of saline–alkali grassland degradation from a plant–soil–microbe perspective and provide a theoretical basis for ecosystem restoration in this region. Full article

Invasion by Spartina alterniflora has detrimental effects on existing ecosystems. Studies have shown that microorganisms can control plant growth and development. However, the root-associated community structures of bacteria, archaea, and fungi of S. alterniflora have rarely been investigated. Here, we applied metagenomics to reveal the bacterial, archaeal, and fungal communities across four root compartments, including the bulk soil, rhizosphere, rhizoplane, and endosphere. Our findings revealed the variation in different community structures. The bacterial and fungal communities exhibited greater potential environmental flexibility than the archaeal community. The endosphere environment had the simplest microbial networks and highest stability. Additionally, we identified root-exuded metabolites from S. alterniflora, which may influence microbial community assembly. Our results indicate that the rhizoplane plays a crucial role in controlling microbial entry into the root, selectively recruiting beneficial microbes for plant growth and colonization, thereby impacting nutrient cycling and plant health. This study provides insights into microbial diversity and function within the S. alterniflora root zone and suggests potential microbial-based strategies for managing this invasive species. Full article

High-density apple (Malus domestica Borkh.) orchards yield fruits as early as three years after planting but nutrient inputs and availability are paramount to a successful orchard; sustainable practices that balance tree growth and production with environmental concerns are not widely available. In this three-year study, we implemented a split-plot design in three orchards across the Mid-Atlantic region of the USA to evaluate integrated soil management approaches that combine locally sourced carbon-based organic mulch with fertilizers on rhizosphere microbes and tree growth. Bacterial and fungal communities were sampled at the end of the first and third growing seasons in addition to soil and tree-related physicochemical properties. Mulch treatment showed the most significant effect on both the bacterial and fungal groups. Most of these changes reflect the increase in soil organic matter and the increase in carbon cycling. Sequence variants belonging to Flavobacteria and Cytophaga were enriched by the mulch application. A key result from this project is the suppression of the relative abundance of potential soil-borne plant fungal pathogens in all orchards in all years. Additionally, arbuscular mycorrhizal fungi were enriched under the mulch treatment. Microbial shifts accompanying the mulch treatments supported higher trunk cross-sectional areas by the third sampling year that increased by 33.5%. Fertilizer treatments had less pronounced effects on microbial communities. These results highlight the potential for using sustainable, integrated nutrient management strategies to promote healthy orchard soils and support vigorous tree growth while reducing fungal pathogens. Our work will contribute to regional and location-specific fertilizer recommendations for apple producers. Full article

This review investigates the multifaceted roles of nitrogen-fixing and phosphate-mobilizing bacteria in natural ecosystems, with a particular focus on their contributions to plant growth and sustainable soil management. These microbial communities contribute substantially to nutrient cycling by converting atmospheric nitrogen into plant-available forms and mobilizing insoluble phosphorus in soil, thereby enhancing soil fertility and promoting sustainable plant productivity. This review synthesizes current knowledge on the mechanisms underlying biological nitrogen fixation, phosphate solubilization and mineralization, and the production of plant growth–promoting metabolites. Particular attention is given to plant–microbe interactions and their role in improving nutrient availability, regulating plant physiological processes, and enhancing tolerance to abiotic stresses such as salinity, drought, and heavy metal contamination. The findings underscore the ecological importance of these plant-associated microbial communities and highlight their potential applications in biofertilizer and biostimulant development for sustainable agriculture and reduced dependence on synthetic fertilizers. Full article

The rhizosphere is a complex microecosystem where soil, roots, and microbes interact to maintain soil ecological functions. Blueberry (Vaccinium spp.), an economically important fruit, has a shallow, fibrous root system with few root hairs, limiting its nutrient absorption. It thrives in acidic, high-organic matter soils, restricting its cultivation in many soil types worldwide. Enhancing blueberry productivity and adaptation by leveraging beneficial rhizosphere microbial communities offers a sustainable solution. This review summarizes the composition of blueberry rhizosphere microbial community across different microenvironments and the blueberry rhizosphere core microbiome. We detail the functional roles of beneficial microorganisms in stimulating nutrient bioavailability and secreting phytohormones. Furthermore, factors influencing microbiome assembly, including cultivars, planting age, and metabolites, are evaluated alongside agricultural management practices. Despite extensive taxonomic characterization, a critical gap remains in understanding the functional synergism between blueberry and its rhizosphere microbiome, particularly the ecological mechanisms underlying host adaptation to acidic and nutrient-limited environments. Overall, future research should focus on developing targeted agricultural practices and synthetic microbial communities to reshape the rhizosphere microbiome, thereby establishing productive, resilient rhizosphere-based microbial systems that support eco-friendly and sustainable agricultural ecosystems. Full article

Drought is a major constraint on crop productivity, and microbial inoculants are increasingly explored to mitigate plant water stress. However, most inoculant discovery pipelines rely on trait-based screening performed outside the ecological context in which beneficial plant-microbe interactions naturally arise. In natural soils, drought-exposed plants can reshape the rhizosphere environment by altering carbon allocation and root exudation, thereby selectively recruiting microorganisms compatible with water-limited conditions and effectively performing an ecological pre-selection. Here, we captured this process during early seedling establishment and leveraged drought-driven rhizosphere recruitment as a nature-guided strategy to nominate bacterial inoculant candidates. Tomato seedlings were grown in natural agricultural soil microcosms under well-watered and drought-stressed regimes, and cultivable bacteria were comparatively isolated from rhizosphere and bulk soil fractions. Recruitment-prioritized isolates were subsequently characterized through biochemical assays and genome-informed analyses to provide functional and taxonomic context and were evaluated in early inoculation assays under water stress. Drought-recruited isolates displayed distinct plant-associated responses, and genome-scale taxonomy indicated that one drought-associated isolate represents a genomically distinct lineage within the genus Paracoccus. Together, these findings highlight drought-driven rhizosphere recruitment as an ecologically grounded framework for identifying stress-compatible bacterial candidates and uncovering previously undescribed rhizosphere diversity. Full article

Plant growth-promoting rhizobacteria (PGPR) are considered promising bio-inoculants for poplar production, but their effects can vary depending on bacterial strain, host genotype, and growth environment. In this study, we evaluated the responses of ten poplar clones representing three taxonomic groups to five indigenous PGPR strains under greenhouse and open-field nursery conditions. Under greenhouse conditions, Priestia aryabhattai GJRr2, Variovorax boronicumulans HNRr1, and a mixed inoculum (Mix) showed the most consistent positive effects. Plant height increased from 86.1 ± 5.6 cm in the control to 156.0 ± 9.4 cm in the GJRr2 treatment, whereas HNRr1 produced the greatest stem diameter (9.01 ± 0.26 mm) and total fresh weight (94.0 ± 6.0 g). Clone identity explained a larger independent fraction of growth variation than bacterial strain, and the strongest integrated responses were observed in I-476, Dorskamp, and Eco28. Field responses were generally weaker, but GJRr2 and Mix still increased height, DBH, and stem volume, whereas ORa was associated with negative responses in these traits. These results demonstrate that PGPR effects in poplar are strain-specific, clone-dependent, and environmentally contingent, indicating that inoculant selection should account for both host genotype and performance stability across growth conditions. Full article

Astragalus membranaceus suffers severe yield and quality losses due to root rot caused by Fusarium solani. To address this, we analyzed the root-associated microbial communities of healthy and diseased plants in northwest China using high-throughput sequencing. Combining community analysis with pot experiments and transcriptomic profiling, we elucidated the molecular mechanisms by which the biocontrol fungus Purpureocilliu lilacinum BP2-7 suppresses root rot. Root rot reshaped root-associated microbial structure, affecting fungal diversity more than bacterial diversity. The antagonistic effect of P. lilacinum BP2-7 against F. solani reached 71.43% in plate assays and 63.7% control efficacy in pot experiments, representing the first report of P. lilacinum application for managing root rot in A. membranaceus. Transcriptomic analysis revealed that P. lilacinum BP2-7 promotes the transition of plants from a damaged to a recovering state by modulating translation and metabolic processes, and enhancing protein homeostasis, while moderately downregulating defense-related responses to alleviate pathogen-induced excessive defense mechanisms. Additionally, twenty candidate genes involved in the direct inhibition of F. solani were identified, suggesting a role in enhancing host resistance. This study supports eco-friendly biocontrol strategies and advances understanding of plant–microbe interactions for managing soil-borne diseases in other important crops. Full article

Jujube (Ziziphus jujuba Mill.) cultivation in arid regions of China faces severe soil constraints, including high alkalinity, low organic matter content, and poor water retention. Although soil amendments have demonstrated potential for improving soil quality, their combined effects on soil–plant–microbe interactions in desert agroecosystems remain poorly understood. This study conducted a three-year field experiment in a desert jujube orchard in southern Xinjiang, China, to evaluate six nitrogen fertilizer management strategies: urea alone (CK) or combined with biochar (NB), bentonite (NP), graphene (NS), biochar plus bentonite (NBP), or microbial inoculants (NW). Soil physicochemical properties, enzyme activities, bacterial community structure, and jujube yield were analyzed. Structural equation modeling (SEM) was employed to elucidate the pathways linking soil amendments to crop productivity. Results showed that NBP was the most effective in improving soil physical structure, significantly reducing bulk density and enhancing water retention capacity compared to the control. The NBP treatment also enhanced soil organic matter (30% increase), available phosphorus (119% increase), and urease activity (44% increase), resulting in the highest jujube yield (7.14 kg per tree). Bacterial community analysis revealed that NBP significantly increased Shannon diversity and enriched Actinobacteriota and Proteobacteria. SEM analysis indicated that urease activity served as a significant mechanistic pathway linking soil organic matter improvements to enhanced crop productivity. These findings demonstrate that combined application of biochar and bentonite with nitrogen fertilizer represents an effective strategy for improving soil quality, enhancing microbial functionality, and increasing crop yield in desert jujube orchards, providing a practical and synergistic amendment combination for sustainable soil management and productivity enhancement in arid agroecosystems. Full article

Maize production in semi–arid irrigated systems depends on soil fertility and an active rhizosphere. We hypothesized that vermiculite enriched with humic substances (HS) or Chlorella vulgaris (CV) would outperform vermiculite alone by improving soil fertility, maize nutrition, and rhizosphere-associated microbial indicators. A field experiment was conducted in southern Kazakhstan under medium–loam sierozem using a randomized block design with three replicates and seven treatments: control, vermiculite at 1 and 2 t ha⁻¹, vermiculite + HS at 1 and 2 t ha⁻¹, and vermiculite + CV at 1 and 2 t ha⁻¹. Amendments were incorporated before sowing, and soil, plant, and microbial measurements were taken before sowing, at V6–V8, and after harvest. Compared with the control, all amendments improved early maize growth, leaf area development, biomass accumulation, and nutrient status, and increased grain yield. The strongest response was obtained with vermiculite + HS at 2 t ha⁻¹, which increased grain yield from 6.48 to 10.24 t ha⁻¹ (+58%). Microbial indicators differed between bulk soil and the rhizosphere, while Pearson correlation and PCA revealed coordinated soil–plant–microbe responses and productivity–linked variables across treatments. Taken together, these results indicate that enriched vermiculite, especially HS–enriched vermiculite at 2 t ha⁻¹, is a promising amendment for improving maize productivity and rhizosphere functioning in semi–arid irrigated systems. Full article

Mulberry (Morus alba L.) is a woody plant primarily cultivated for silkworm breeding, with significant economic and ecological functions. Its nitrogen use efficiency directly affects leaf yield, quality, and environmental adaptability. The main inorganic nitrogen forms available for plant uptake in soil are ammonium nitrogen and nitrate nitrogen, and plant uptake and assimilation of these two nitrogen sources often exhibit species-specific preferences. This review systematically summarizes the research progress on nitrogen uptake preferences in mulberry, confirming that this species generally shows a preferential uptake of nitrate. Specifically, when supplied with nitrate or a mixed nitrogen source dominated by nitrate, mulberry exhibits better performance in growth and development, photosynthetic efficiency, and accumulation of secondary metabolites. This review further discusses the physiological characteristics and underlying regulatory mechanisms responsible for this preference, and analyzes key factors affecting nitrogen uptake preferences, including soil properties, environmental stresses, and microbial interactions. It should be noted that while controlled experiments have yielded important insights, the applicability of these findings under complex field conditions still requires further validation through field trials. Finally, future research directions are prospected, including in-depth dissection of molecular mechanisms, field validation, plant-microbe interactions, and nutritional strategies for stress resistance, aiming to provide a theoretical basis for efficient cultivation and precise nitrogen management of mulberry. Full article