Lead (Pb) contamination of soils is a persistent global problem due to its non-biodegradable nature and toxicity to plants, ecosystems, and human health. Phytoremediation offers a sustainable alternative to conventional technologies, but its efficiency is limited by low Pb bioavailability, restricted root-to-shoot translocation, and Pb-induced phytotoxicity. This study presents a systematic review of assisted phytoremediation of Pb-contaminated soils, integrating remediation performance with biometric, physiological, and biochemical plant responses. Following PRISMA guidelines, 55 studies retrieved from Scopus, PubMed, and Web of Science were analyzed. Data on soil Pb concentrations, plant species, experimental conditions, enhancement strategies, Pb uptake and translocation, and plant responses were extracted and standardized. Most studies (76.36
Phosphorus (P) limitation in soils severely constrains plant growth and ecosystem productivity. This study tested a promising strategy to solubilize immobilized soil P using fungi isolated from abandoned phosphate mines. Excellent phosphate-solubilizing fungi (PSF) were screened from a phosphate mining site in Haikou, Kunming, China to construct a synthetic community (SynCom) and explore its effects on plants in acidic P-immobilized soil. A total of 609 fungal isolates was screened and 69 isolates exhibited phosphate-solubilizing potential. Three strains—Aspergillus sp. 5C-22, Diaporthe sp. 7C-37, and Irpex sp. 9B-08—were ultimately chosen for their high P-solubilization efficiency, adaptability to varying pH and temperature, and ease of cultivation to assemble into a SynCom. The SynCom significantly promoted the growth of three forage species (Pennisetum purpureum, Arundo donax, and Zea mays), increasing shoot biomass by 35.5
Climate warming is shifting the timing of extreme drought events, with subsequent impacts on plant growth. However, how extreme drought timing modulates plant biomass allocation in alpine meadows remains poorly understood. We conducted a four-year precipitation manipulation field experiment (2021–2024) in an alpine meadow on the Qinghai-Tibet Plateau using rainout shelters to simulate early- and late-growing-season extreme drought in a two-factor randomized complete block design. We annually surveyed plant above- and belowground biomass, community characteristics and soil physicochemical properties. Two-way repeated-measures ANOVA, structural equation modeling and linear regression were applied to quantify treatment effects and biotic–abiotic correlations. Late season drought exerted a stronger effect on biomass allocation than early season drought. It increased the ratio of root to shoot by 56
Efficient phosphorus (P) management is a major challenge in agriculture. Plants exhibit diverse P-mobilizing mechanisms, which can affect the P uptake by the subsequent crop. Information on this topic is scarce, and this study aimed to assess the effect of different cover crops (CC) on P uptake by the subsequent cash crop (durum wheat, Triticum durum L.) under different soil conditions and fertilization regimes. A pot experiment was conducted under controlled conditions involving different CCs: Avena sativa (Av); Vicia sativa (Vs); Vicia narbonensis (Vn), Av + Vs. and Av + Vn. Two soils with low available P status and different properties dominating P dynamics were used: a carbonate-rich soil (S-Ca) and a Fe oxide-rich soil (S-Fe). After CC termination and residue incorporation, wheat was grown with and without P fertilization. Olsen P significantly decreased after CC termination but partially recovered after CC incorporation due to P turnover from decaying material and microbial activity, explaining why P uptake by unfertilized wheat did not decrease after CC. Depending on the soil, CCs increased the apparent P recovery (APR) from applied fertilizer by 2–6 times. Oat was the most effective in increasing APR in the S-Fe, and Vs and Av + Vn in the S-Ca soil. Physiological P use efficiency (PUtE) worsened with some CCs when P fertilizer was applied. These results reveal that CCs contribute to greater efficiency in the use of applied P and enhance soil P cycling, thus contributing to more sustainable P management in agroecosystems.
To address soil salinization and alkalization, a key constraint to global agricultural sustainability, the development of efficient and stable synthetic microbial communities is of critical importance. In this study, a culturable rhizobacterial community (KRBC) was enriched from the rhizosphere of the salt- and alkali-tolerant plant Knorringia sibirica (Laxm.) Tzvelev. The mechanism by which KRBC enhances rice tolerance to salt and alkali was analyzed through 16S rRNA sequencing and PICRUSt2 functional prediction. Based on the "key genus—key function" strategy, which involves selecting microbial genera and functions that assist rice in tolerating salt-alkali stress, strains were selected from KRBC to construct synthetic communities (SynComs) and their simplified versions (sfSynComs), and their effects were verified through pot experiments. KRBC inoculation significantly promoted the growth and yield of rice under salt-alkali stress and reshaped the rhizosphere microbiota structure. Staphylococcus was identified as a key functional group, and the amino acid biosynthesis pathway was significantly enriched. Based on this, 17 amino acid-producing strains (16 belonging to Staphylococcus) were successfully screened, and a synthetic community was constructed. Pot experiments confirmed that both SynComs and sfSynComs could effectively promote rice growth, with effects comparable to those of KRBC. This study demonstrated the feasibility of designing synthetic communities from the rhizosphere microbiota of salt- and alkali-tolerant plants. Both the synthetic community (SynComs) and its simplified version (sfSynComs) were successfully developed and experimentally evaluated in pot experiments, providing a theoretical basis and technical approach for the development of efficient and simplified microbial products with clearly defined functional traits suitable for salt-alkali soils.
Shrub layers are functional determinants of soil processes, yet their role in regulating soil organic matter (SOM) fractions, dissolved compounds, and enzymatic activity remains insufficiently quantified. This study evaluated the effects of three shrub species—European hazel (Corylus avellana), alder buckthorn (Frangula alnus), and rowan (Sorbus aucuparia)—on soil biogeochemical functioning. Soil chemical properties, SOM fractionation, dissolved organic matter, ionic composition, and enzymatic activity were analysed in Scots pine (Pinus sylvestris) stands on sandy Podzols in southern Poland. Soils under these shrubs were compared against pine monocultures. Labile SOM fractions and mineral-associated organic matter (MAOM) were quantified to distinguish between short-term nutrient cycling and long-term carbon stabilization using multivariate and regression analyses. Soils under shrubs exhibited significantly higher total carbon (C) and nitrogen (N), enhanced C and N accumulation in light SOM fractions, and increased concentrations of dissolved organic C and N compared to pine monocultures. Corylus avellana exerted the strongest influence by significantly enhancing labile soil organic matter fractions, enzymatic activity, and dissolved organic carbon and nutrient mobility, whereas rowan showed weaker and more selective effects mainly associated with longer-term stabilization processes. In contrast, buckthorn primarily stimulated dissolved organic carbon and ion leaching, indicating species-specific differences in the regulation of soil carbon turnover and nutrient cycling. Since shrub species increase solute mobility and accelerate nutrient turnover, they have a basic impact on soil biogeochemistry. The findings indicate that, in pine-dominated forests, shrubs actively regulate soil processes rather than serving only as structural understory elements.
Although synthetic communities of complementary strains are novel strategies for controlling soil-borne diseases, research on Trichoderma combinations for red pepper Phytophthora blight management remains scarce. This study investigated the efficacy and mechanisms of Trichoderma harzianum T891 and T58, applied individually or in combination, against this disease. The effects of Trichoderma strains on incidence, plant growth, and peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) activities and malondialdehyde (MDA) content were investigated with pot experiment. Microbial mechanisms were explored via amplicon sequencing. Compared to pathogen-infected control, single inoculation of T58 or co-inoculation of the two strains significantly reduced blight incidence, and Trichoderma treatment significantly promoted plant growth. T891-T58 combination led to the lowest disease incidence (a reduction by 90.9
Straw and its derivatives have been widely used to improve black soil fertility, but their effect on improving pore characteristics and hydraulic properties remains inconclusive. We examined the effects of four organic treatments on black soil at an equivalent carbon application rate of 4800 kg C ha−1: (i) no amendment (CK), (ii) corn straw incorporation (CS), (iii) straw–manure compost (CSM), and (iv) straw-derived biochar (BC). Measurements of soil pore properties and hydraulic characteristics were conducted, followed by an analysis of their interconnections. Organic amendments reduced soil bulk density by 11.0–14.0
This study aimed to evaluate the stability of typical plantation communities in the Loess Hilly Region of Western Shanxi, China, and to assess the relationship among community stability, community structure, soil physicochemical properties, and natural regeneration. Field surveys and laboratory analyses were conducted in five stand types: pure plantations of Robinia pseudoacacia, Platycladus orientalis, and Pinus tabuliformis, and mixed plantations of P. tabuliformis + R. pseudoacacia, and P. orientalis + R. pseudoacacia. Community stability was assessed using the M. Godron method, while principal component analysis and random forest modeling were used to evaluate the relative importance of explanatory variables. A total of 82 plant species from 36 families and 72 genera were recorded, with Rosaceae, Asteraceae, and Fabaceae as dominant families. Mixed plantations had more complex community structure, higher diversity indices, and greater aboveground biomass than pure plantations. Natural regeneration was generally low, with most seedlings in small- and medium-sized classes and limited seed availability. The regeneration layer was insufficiently developed. Community stability was higher in mixed plantations than in pure plantations. The Euclidean distance (ED) followed the order P. tabuliformis + R. pseudoacacia < P. orientalis + R. pseudoacacia < P. tabuliformis < P. orientalis < R. pseudoacacia, with smaller EDs indicating higher stability. Mixed plantations, especially P. tabuliformis + R. pseudoacacia, showed higher community stability than pure plantations. Current stability was primarily associated with understory diversity and integrated soil conditions, whereas regeneration-related variables showed relatively limited explanatory importance. However, low natural regeneration may constrain long-term stand persistence.
Drought reduces wheat yields, yet field-scale quantification of root water uptake (RWU) remains challenging because below-ground processes are difficult to monitor. This study developed a non-invasive hydrogeophysical framework integrating Electrical Resistivity Tomography (ERT), TDR-based soil monitoring, and depth-aware Random Forest calibration to quantify depth-resolved RWU and evaluate genotype-specific water-use strategies under terminal drought. Time-lapse ERT (44 surveys, ≥ 3 week⁻1) was combined with TDR sensor measurements of soil water content (n = 278 paired ρ–θ observations) to convert resistivity measurements into depth-resolved RWU estimates across 0.1–1.0 m depth. Five petrophysical models were evaluated using date-grouped fivefold cross-validation, with the depth-aware Random Forest performing best. Three wheat genotypes with contrasting root architectures were monitored under terminal drought (142 mm available water). ERT-derived RWU were analysed alongside stomatal conductance, chlorophyll fluorescence, and grain yield. ERT resolved RWU strategies among genotypes. WM-203 exhibited aggressive, coordinated multi-layer water extraction across the soil profile (r = 0.80–0.98), whereas WM-140 showed a delayed uptake strategy characterized by early deep-layer dominance followed by mid- and deep-profile engagement, and IPLR-760 displayed inconsistent uptake with mid-profile hydraulic decoupling. Genotypic RWU rankings were consistent with stomatal conductance and grain yield, spanning from 7.0 t ha⁻1 in WM-203 to 1.5 t ha⁻1 in IPLR-760 despite comparable total water extraction. ERT-based quantification of RWU provides a robust, non-invasive approach for resolving genotype-specific water-use strategies under field conditions. The framework enables characterization of water-use coordination patterns and offers a tool for phenotyping drought-resilient wheat genotypes.
The wild barley, Hordeum brevisubulatum (Trin.) Link, is a high-quality forage grass and exhibits enhanced stress resistance when infected by endophytes. For this symbiotic system, a systematic assessment was conducted to examine the relationships among growth traits, nutritional quality, and salt tolerance across different samples, with the final aim to identify superior germplasm resources. Ecotypes collected from different regions were studied. Field experiments were conducted to evaluate agronomic traits and nutritional quality. Concurrently, greenhouse experiment subjected the ecotypes under salt stress treatment to monitor their growth. Comprehensive evaluation and correlation analysis were employed to identify superior ecotypes. Significant variations in agronomic traits, forage quality and salt tolerance were detected between different ecotypes. Crown breadth, acid detergent fiber, and relative cell membrane permeability had the significant direct path coefficient on relative feeding value. Significant negative correlations between quality and agronomic traits and between quality and salt tolerance were found, whereas significant positive correlation between agronomic traits and salt tolerance was detected. Our efforts identified three ecotypes with good agronomic traits and salt tolerance that may be used for developing new varieties for ecological restoration and forage.
Grazing enclosure duration and nitrogen (N) addition both regulate soil organic carbon (SOC) fractions, yet their effects across restoration stages remain poorly understood. We conducted a 12-year N addition experiment on the Chinese Loess Plateau at three sites with initial enclosure durations of approximately 10, 20, and 30 years in 2013, corresponding to approximately 21, 31, and 41 years at sampling in 2024. We measured aboveground biomass, Shannon diversity, soil pH and inorganic N availability, and SOC fractions in the 0–20 cm soil layer. Aboveground biomass was highest at the mid-term (20 years) enclosure site, whereas plant diversity was highest at the short-term (10 years) enclosure site. At the latter site, N addition increased aboveground biomass but reduced plant diversity. SOC responses to N addition differed among grasslands with different enclosure durations. N addition decreased particulate organic carbon (POC; 0.4
Exotic plant invasions involve interactions with local plants. However, how the invasive plant Ageratina adenophora selectively enriches above- and belowground microbes from local plants, alters its own metabolites, and thereby regulates its growth remains unclear. Microbial and metabolite analyses were conducted on A. adenophora seedlings showing growth promotion or inhibition after receiving leaf or soil inoculants. Leaf inoculation induced glutathione metabolism, isoflavonoid biosynthesis and carbon metabolism, while soil inoculation triggered cutin, suberin and wax biosynthesis, and linoleic and arachidonic acid metabolism. Key differential microbes included Paenibacillus, which were highly enriched in both growth-promoted and growth-inhibited seedlings. Bacillus was mostly associated with growth promotion in most cases, except that it was negatively correlated in soil-inoculated roots. Growth-inhibited seedlings featured defense-related pathways such as cysteine and methionine metabolism, while growth-promoted seedlings showed growth-related pathways like tryptophan and arginine biosynthesis. In inhibited seedlings, microbes correlated positively with defense-related lipid metabolites. In promoted seedlings, defense metabolites including coumarins and flavonoids correlated negatively with microbes. Collectively, invader A. adenophora selectively enriched native microbes that regulate host resource allocation, thereby driving differential growth responses. Our findings provide important insights into exotic plant–microbe interactions by facilitating or hindering invasions.
The processes that structure plant communities are understood better in forests than in herbaceous systems. Here, we test the hypothesis that mycorrhizal responsive herbaceous plant species experience favourable plant-soil feedbacks compared to less mycorrhizal responsive species. We extracted plant-soil feedback information for herbaceous species from a recent meta-analysis and collated this information with three sources of mycorrhizal responsiveness data. Our results support our hypothesis that mycorrhizal responsive plants, notwithstanding if they experience positive or negative mycorrhizal responses, receive more positive plant-soil feedbacks, and were robust to most of the sensitivity tests we carried out. We uncover an underappreciated mechanism that could confer spatiotemporal stability across herbaceous plant communities. Mycorrhizal responsive plant species may receive less negative plant-soil feedback but most likely experience higher interspecific competition. These effects could promote a balance of mycorrhizal responsive and less-mycorrhizal responsive species within herbaceous systems.
This study aimed to evaluate the combined effects of lime, nitrogen (N), and phosphorus (P) on wheat yield, nutrient use efficiency, and grain zinc (Zn) concentration under acidic soil conditions. A field experiment was conducted using a split-plot factorial design, with two lime levels as main plots and five N rates interacted with four P rates as sub-plots. Soil chemical properties, wheat yield, nutrient uptake and recovery efficiency, and grain Zn concentration were measured over two growing seasons. Lime improved soil chemical properties associated with acidity and enhanced N and P uptake and recovery efficiency. N was identified as the dominant yield-limiting nutrient, while increasing P application revealed a trade-off between wheat yield and grain Zn concentration, independent of lime and N management. Wheat yields showed diminishing returns to N and P applications, with maximum yields of 4.8 t ha⁻1 in the first year (150 kg N ha⁻1, 40 kg P ha⁻1) and 5.6 t ha⁻1 in the second year (100 kg N ha⁻1, 20–40 kg P ha⁻1). Median yield gains were greatest for N (3.5 t ha⁻1), followed by P (2.0 t ha⁻1) and lime (1.1 t ha⁻1). Grain Zn concentration rarely exceeded 35 mg kg⁻1. Lime increased grain Zn concentration, while excessive N and incremental increases in P rates reduced grain Zn. Integrating lime with balanced fertilization strategies supports sustainable intensification of Ethiopian wheat production. However, cautious P management and complementary Zn supplementation are needed to balance high productivity with grain nutritional quality.
Dark Septate Endophytes (DSE) and Epichloë endophytes are widespread symbionts that modulate host fitness and responses to environmental conditions. While their individual roles are documented, their combined influence on phosphorus (P) partitioning remains unclear. This study evaluated how dual colonization by Epichloë and a DSE strain modulates internal P allocation in the forage grass Bromus auleticus under varying P supply. Twenty-nine DSE strains from B. auleticus roots were screened for P-solubilization in both solid and liquid NBRIP media. The most efficient strain, identified as Thelonectria blackeriella, was selected for a greenhouse factorial experiment involving Epichloë (E + /E-), DSE inoculation (DSE + /DSE-), and two P-supply levels (non-supplemented vs. supplemented). Following harvest, P concentrations were measured in tissues, and a Phosphorus Translocation Factor (PTF), calculated as the shoot-to-root P concentration ratio, was used to assess the patterns of internal P partitioning. T. blackeriella effectively solubilized inorganic P in vitro. Under greenhouse conditions, shoot P concentration was strongly modulated by the DSE colonization. Without P supplementation, Epichloë endophytes increased the PTF, prioritizing allocation to aerial tissues. Conversely, under P supplementation, dual-symbiotic plants (E + DSE +) exhibited significantly higher root P concentrations, suggesting enhanced root P retention. The symbionts exhibited functional complementarity: Epichloë endophytes promote aerial P allocation under low supply, while DSE facilitates root P accumulation under higher supply. This dual-symbiosis response influences the host’s internal P partitioning, potentially enhancing nutritional resilience and post-grazing recovery in forage systems.
Salinity is a serious constraint on agricultural output worldwide, impacting millions of hectares and inflicting large economic losses each year. Conventional reclamation efforts are typically unsustainable, emphasizing the urgency of novel alternatives to ensure food security. The present review focuses on the multifaceted mechanisms underlying nanobiochar (nano-BC)-mediated salinity tolerance in plants, with emphasis on physiological, biochemical, molecular, and rhizosphere microbiome responses. It further evaluates the potential of nano-BC for sustainable management of salt-affected soils and highlights key knowledge gaps and future research priorities. Nano-BC employs multifaceted mechanisms to mitigate salinity-induced damage, including modulation of physiological and molecular responses, maintenance of ionic homeostasis, and improvement of soil properties and rhizosphere microbiome dynamics. Collectively, these effects help preserve cellular turgor, maintain metabolic stability, and alleviate salinity-induced stress. Here, we highlight the influence of feedstock type and pyrolysis conditions on the production, physicochemical properties, and functional performance of nano-BC. We also provide comparative insights into the effectiveness of nano-BC versus conventional soil amendments. Finally, emerging research directions are discussed, with emphasis on the need to elucidate the complex nano-BC–salinity interactions and optimize its application, thereby providing a roadmap for sustainable agriculture in saline environments.
Tree size drives changes in leaf functional traits and phyllosphere microbial communities. However, it remains unknown how these changes influence litter chemical properties and associated microbial communities, and subsequently modulate litter decomposition. We conducted a field decomposition experiment in a temperate forest using leaf litters collected from four dominant tree species in two size classes (classified by diameter at breast height). We measured initial litter chemical properties and determined both bacterial and fungal communities in litters using high-throughput sequencing. After 6 months of decomposition, litter mass loss (
This study aimed to evaluate the eff ects of irrigation water salinity (0–4‰) on soil chemical properties, plant physiological responses, and rice yield of Oryza sativa L. cv. Dai Thom 8 under controlled greenhouse conditions, and to identify the salinity threshold associated with significant yield reduction. Rice plants were grown under controlled greenhouse conditions and irrigated with water of different salinity levels ranging from 0 to 4‰. Soil electrical conductivity (EC) and total nitrogen (TN) were monitored to assess changes in soil chemical conditions. Plant physiological responses were evaluated based on chlorophyll content and gas-exchange parameters, while grain yield was determined at harvest. Relationships among soil properties, physiological traits, and rice yield were further examined across the salinity gradient. Increasing irrigation water salinity progressively increased soil EC and decreased TN, indicating deterioration of soil chemical conditions. Salinity stress also reduced chlorophyll content and gas-exchange parameters, reflecting impaired plant physiological performance. Rice yield showed a pronounced nonlinear response to increasing salinity, with a marked transition at approximately 1.4‰, corresponding to an approximately 50
Rice is a staple crop for over half the global population, but rice cultivation is also a significant source of methane (CH4) emissions, placing it at the heart of the climate–food security challenge. While silicon (Si) fertilization has long been valued for its agronomic benefits in rice cultivation, its role in modulating soil microbial processes to mitigate greenhouse gas emissions remains underexplored and underutilized in climate policy. This opinion article aims to highlight the silicate–microbiome interface as a pivotal yet overlooked leverage point for achieving sustainable rice intensification and effective climate mitigation. We critically examine how disciplinary constraints, entrenched soil fertility paradigms, and a policy preference for high-tech solutions have hindered the integration of Si–microbe interactions into mainstream climate-smart agriculture strategies. Synthesizing recent advances in rhizosphere microbiology and soil biogeochemistry, we introduce a novel conceptual framework—Silicon-Mediated Microbial Climate Regulation (SiMCR)—to elucidate the mechanistic links between Si application, microbial community dynamics, and reduced CH4 emissions. The scope encompasses recommendations for multidisciplinary research agendas, regulatory updates to recognize quality-screened Si fertilizers as climate-smart soil amendments, and their inclusion in national climate action plans (e.g., Nationally Determined Contributions) and sustainable intensification metrics. Embracing Si-mediated microbial regulation offers a scalable, nature-based strategy to decouple rice production from environmental harm. We argue that without deliberately incorporating Si–microbe interactions into both research and policy frameworks, the goal of truly climate-smart rice systems will remain unattainable. Urgent action is needed to unlock this neglected nexus for global food and climate security.
