Interannual Covariation of Rhizosphere Microbiomes and Plant Performance in Coastal Saline–Alkali Soils Ameliorated by Nitraria tangutorum

Halotolerant plant growth-promoting rhizobacteria from rice and wheat in sodic soils: Characterization for their potential to alleviate salt stress

It is suggested that selected halotolerant isolates possess multifunctional traits including salt tolerance and potential nutrient-solubilizing capacity, making them promising candidates for biofertilizer development and sustainable agriculture in salt-affected regions.

Contrasting the Microbial Communities in Rhizosphere and Bulk Soils Across Different Eucommia ulmoides Planting Sites and Their Soil Chemical Driving Mechanisms

Soil multifunctionality (SMF) is a core indicator of plantation soil ecological function, and microbial diversity plays a vital role in sustaining it. However, cross-site rhizosphere and bulk SMF disparities and their microbial driving mechanisms remain unclear in Eucommia ulmoides plantations. Here, we collected rhizosphere and bulk soils from three typical sites (Mengzhou, MZ; Liangyuan, LY; and Yuanyang, YY). Soil chemical properties, extracellular enzymes, microbial alpha diversity, community composition and cross-kingdom network topology were measured. Correlation heatmaps, random forest, Redundancy analysis (RDA) and Partial least path modeling (PLS-PM) were adopted to quantify SMF predictors and regulatory pathways. Rhizosphere soils possessed significantly higher alkaline hydrolyzable nitrogen (AN), available phosphorus (AP) and available potassium (AK) than bulk soils at all sites. LY rhizosphere showed the greatest soil organic carbon (SOC), total potassium (TK), available nutrients and enzyme activities, while YY had higher total nitrogen (TN) and AP, yet the lowest enzyme levels. Rhizosphere bacterial and fungal alpha diversity was consistently higher across locations. SMF varied distinctly by site and compartment: LY had substantially higher SMF than MZ and YY in both rhizosphere and bulk soils, with rhizosphere SMF being consistently greater than bulk values across all sites. The PLS-PM (GOF = 0.70) indicated that soil chemical properties regulated SMF via dual pathways: they directly promoted microbial co-occurrence networks and indirectly modified network structure by altering fungal diversity, while suppressing bacterial diversity. Total effect analysis identified soil chemical properties and microbial co-occurrence networks as the core drivers of SMF variation. This work clarifies that rhizosphere effects and soil chemical properties jointly drive SMF by regulating microbial diversity and co-occurrence networks, offering theoretical guidance for sustainable soil management in E. ulmoides plantations.

Unveiling the bacterial community structure and soil properties in bulk and rhizospheric compartments of Tamarix gallica from an arid Algerian saline ecosystem

Soil salinization is among the most critical threats to agriculture and food security, particularly in arid and semi-arid regions. Despite their ecological and agricultural significance, the microbial processes in saline soils of arid regions remain poorly characterized. This first 16S rRNA amplicon-based study of Algerian saline soils examines bacterial communities and physico-chemical properties in the Naama salt flat, focusing on both bulk and rhizosphere soils associated with Tamarix gallica L. Bacterial diversity and community composition were analyzed through high-throughput 16S rRNA gene sequencing on an Illumina MiSeq platform, and soil parameters, including salinity, nutrients, organic carbon, and water retention were measured. Sequence data were processed with QIIME2, and multivariate analyses were applied to compare soil types and explore correlations between taxa and soil properties. Rhizosphere soils tended towards higher Na+, K+, and Ca2+ levels, whereas bulk soils showed greater phosphorus availability. Bacterial diversity was lower in the rhizosphere, which was characterized by a distinct taxonomic composition, including taxa such as Promicromonospora and Nocardioides potentially involved in nutrient cycling and stress adaptation. Correlation analyses revealed microbial adaptations to salinity and nutrient availability. This study lays the groundwork for developing plant growth-promoting rhizobacteria aiming to combat land degradation and contribute to long-term food security and environmental resilience in arid regions.

No-tillage shapes a Sinorhizobium-centered rhizosphere network in saline-alkali soybean fields

Responses of growth and quality of Glycyrrhiza uralensis to salt-alkali-tolerant microbial inoculant via the remodeling of rhizosphere microenvironments in moderate and severe saline-alkali soils

The combined application of microbial inoculation and seedling transplanting is recommended for large-scale and high-quality cultivation of G. uralensis in moderately saline-alkali soils of arid northwestern China, as this integrated practice maximizes plant growth, medicinal compound accumulation, and rhizosphere microenvironment optimization.

Continuous Cropping Chinese Chive Alters Rhizosphere Metabolites and Microbial Communities

Continuous cropping obstacles severely constrain Chinese chive (Allium tuberosum) production, yet the integrated mechanisms involving soil properties, microbial communities, and rhizosphere metabolites remain unclear. We hypothesized that long-term monoculture induces soil degradation and shifts rhizosphere microbiomes via accumulated putative allelochemicals, with a critical tipping point. Rhizosphere soils from 1-to-5-year continuous cropping fields were analyzed using high-throughput sequencing, non-targeted metabolomics, and physicochemical assays. Results showed significant salinization and nutrient depletion after three years, along with a slight decrease in soil pH. Enzyme activities (sucrase, urease, alkaline phosphatase, and catalase) first rose then fell. Bacterial richness declined sharply after four years, with beneficial genera (such as Devosia) decreasing and pathogenic genera (such as Thelonectria) enriched. Metabolomics identified 1175 metabolites, primarily enriched in linoleic acid and α-linolenic acid pathways. Oxidized fatty acids accumulated significantly and correlated positively with pathogen abundance and negatively with beneficial bacteria. We conclude that continuous chive cropping exceeding three years is associated with soil degradation via putative allelochemical accumulation and pathogen enrichment. We recommend crop rotation after three years, offering a theoretical basis for sustainable chive production.