Search Results (75)

Soil salinization remains a critical constraint on global land sustainability, severely limiting agricultural output and ecosystem resilience. To address this issue, a field trial was implemented to investigate the interactive benefits of vermicompost (VC) and a novel soil conditioner derived from coal gasification slag-based soil conditioner (CGSS) in mitigating saline–alkali stress. The perennial forage grass Leymus chinensis, valued for its ecological robustness and economic potential under adverse soil conditions, served as the test species. Five treatments were established: CK (unamended), T1 (CGSS alone), T2 (VC alone), T3 (CGSS:VC = 1:1), T4 (CGSS:VC = 1:2), and T5 (CGSS:VC = 2:1). Study results indicate that the combined application of CGSS and VC outperformed individual amendments, with the T4 treatment demonstrating the most effective results. Compared to CK, T4 reduced soil electrical conductivity (EC) by 12.00% and pH by 5.17% (p < 0.05), while markedly enhancing key fertility indicators—including soil organic matter and the availability of nitrogen, phosphorus, and potassium. Thus, these improvements translated into superior growth of L. chinensis, reflected in significantly greater dry biomass, expanded leaf area, and increased plant height. Additionally, the T4 treatment increased soil microbial richness (Chao1 index) by 21.5% and elevated the relative abundance of the Acidobacteria functional group by 16.9% (p < 0.05). Hence, T4 treatment (CGSS: 15,000 kg·ha⁻¹; VC: 30,000 kg·ha⁻¹) was identified as the optimal remediation strategy through a fuzzy comprehensive evaluation that integrated multiple soil and plant indicators. From an economic perspective, the T4 treatment (corresponding to a VC-CGSS application ratio of 2: 1) exhibits a lower cost compared to other similar soil conditioners and organic fertilizer combinations for saline–alkali soil remediation. This study not only offers a practical and economically viable approach for reclaiming degraded saline–alkali soils but also advances the circular utilization of coal-based solid waste. Furthermore, it deepens our understanding of how integrated soil amendments modulate the soil–microbe–plant nexus under abiotic stress. Full article

Phytoremediation is a cost-effective and sustainable method for the remediation of minewaste contaminated with heavy metals such as arsenic (As). However, mine waste soil is often nutrient-limited, especially in nitrogen (N), impairing plant growth and phytoremediation. This study aimed to assess how planting density together with soil amendments, biochar, and an isolated indigenous nitrogen-fixing bacterium (NFB) (Bacillus subtilis) affect the efficacy of phytoremediation by Juncus pauciflorus of an As-contaminated mine waste soil from Bendigo, Victoria. Three plant densities, including 9, 26, and 44 plants/m², were grown in As-contaminated mine waste soil amended with biochar (10% w/w) and B. subtilis (8.1 × 10⁸ CFU/mL) and incubated for 100 days. Plant biomass, plant As uptake, soil As concentration, bacterial abundance (total and NFB using 16S and nifH gene copy numbers, respectively), and total soil N were assessed. Juncus pauciflorus at a higher density (44 plants/m²) promoted the greatest biomass and total As uptake, 70.22 g/m² and 209.53 mg/m², respectively. Plant density significantly influenced the root–shoot partitioning of As. Higher densities increased shoot uptake (BAF_soil→shoot), and TF_root→shoot values remained >1 across all treatments, confirming the active translocation of As to the shoots, suggesting both phytostabilisation and phytoextraction potential by J. pauciflorus. Planting density significantly reduced soil As, ranging from 8000 mg/kg to 9500 mg/kg, compared to the initial concentration (13,032 mg/kg). The abundance of 16S and nifH genes was stable among treatments, ranging from 7 log₁₀ copies/g to 12 log₁₀ copies/g. TN content in soils amended with 44 plants/m² contained the highest TN content at day 33, approximately 7000 mg/kg. This study is the first to report that higher planting density of J. pauciflorus amended with biochar and NFB provides the strongest phytoremediation performance in highly As-contaminated mine soil by enhancing As uptake and accumulation in aboveground biomass. Most importantly, the results show that plant density also regulates the plant’s remediation strategy, shifting J. pauciflorus between phytostabilisation at dense planting and greater phytoextraction at lower density. These findings support the use of native plants in combination with biochar and microbial amendment as a sustainable strategy for remediating As-contaminated mine waste. Full article

Soil co-contamination with cadmium (Cd) and zinc (Zn) poses serious threats to environmental safety and public health. This study investigates the enhancement effect and underlying mechanism of the biodegradable chelator Ethylenediamine-N,N′-disuccinic acid (EDDS) on phytoremediation of Cd-Zn contaminated soil using Sedum lineare. The results demonstrate that EDDS application (3.65 g·L⁻¹) effectively alleviated metal-induced phytotoxicity by enhancing chlorophyll synthesis, activating antioxidant enzymes (catalase and dismutase), regulating S-nitrosoglutathione reductase activity, and promoting leaf protein synthesis, thereby improving photosynthetic performance and cellular integrity. The combined treatment significantly increased the bioavailability of Cd and Zn in soil, promoted their transformation into exchangeable fraction, and resulted in removal rates of 30.8% and 28.9%, respectively. EDDS also modified the interaction patterns between heavy metals and essential nutrients, particularly the competitive relationships through selective chelation between Cd/Zn and Fe/Mn during plant uptake. Soil health was substantially improved, as evidenced by reduced electrical conductivity, enhanced cation exchange capacity, and enriched beneficial microbial communities including Sphingomonadaceae. Based on the observed ion antagonism during metal uptake and translocation, this study proposes a novel “Nutrient Regulation Assisted Remediation” strategy to optimize heavy metal accumulation and improve remediation efficiency through rhizosphere nutrient management. These findings confirm the EDDS–S. lineare system as an efficient and sustainable solution for remediation of Cd–Zn co-contaminated soils. Full article

Lead (Pb) pollution in wastewater is an immense problem for public health and the environment because it persists in the water bodies for a long period of time. Over the past years, many different techniques of Pb remediation have been discovered to eliminate Pb pollution. This systematic review analyzed the major findings of Pb removal from wastewater using microbial biosorption, agro-waste- and fruit peel-based adsorbents, plant-assisted phytoremediation, engineered biochars, clay and natural minerals, and nanomaterials. Each of these methods is critically reviewed in terms of removal efficiency, limitations, cost-effectiveness, how it works, how well it eliminates the problem, environmental compatibility, regeneration potential, and scalability, as supported by recent experimental and case studies. This review provides a comprehensive comparison of all the remediation methods in one framework. It also shows the potential of the integrated and hybrid systems, a combination of biological and high-technology material-based strategies, to reach high-performance Pb remediation in the long run. Therefore, the study aims to assist policymakers, environmental engineers, and researchers who are interested in finding a sustainable solution to Pb contamination by providing a comparative overview of the existing and recently developed remediation methods. Full article

The increasing presence of microplastics (MPs) in terrestrial ecosystems, particularly when combined with organic pollutants and heavy metals, presents a considerable environmental challenge. This review examines the intricate interactions between MPs, co-contaminants (both organic and inorganic), and plants involved in phytoremediation processes. A literature search was performed across the databases Scopus, ScienceDirect, and Google Scholar, covering the timeframe from 2015 to 2025. The studies selected specifically addressed the synergistic and antagonistic effects of microplastics in conjunction with heavy metals or organic pollutants (such as PAHs and pesticides) within plant–soil systems. The findings reveal that MPs influence pollutant mobility, bioavailability, and toxicity through adsorption and desorption mechanisms, leading to varied implications for plant growth, microbial communities, and contaminant uptake. Depending on the physicochemical characteristics of MPs and co-pollutants, the effects can range from increased phytotoxicity to diminished contaminant accumulation in plants. Additionally, physiological and molecular disruptions, including oxidative stress, hormonal imbalances, and impaired enzymatic activity, were frequently noted in co-contamination scenarios. Recent developments, such as the creation of genetically modified hyperaccumulator plants and the use of nanotechnology and microbial consortia, demonstrate potential to enhance phytoremediation efficiency in complex polluted soils. This review underscores the pressing need for integrated, multidisciplinary strategies to overcome the limitations of existing phytoremediation methods in co-contaminated environments. Future research should focus on standardized methodologies, a mechanistic understanding, and the safe implementation of emerging biotechnologies for sustainable soil remediation. Full article

Chemical and plant-based strategies have become increasingly critical for the remediation of saline–alkali soils. However, the underlying mechanisms driving improvements in soil quality and ecological functionality remain insufficiently understood. In this study, we adopted a synergistic remediation approach that integrated multiple switchgrass (Panicum virgatum L.) cultivars with a coal-based soil amendment to enhance saline–alkali land. A field experiment was conducted using five switchgrass varieties (YM-1, YM-2, YM-3, YM-4, and YM-5), each receiving a uniform application of the coal-based soil conditioner at 10 t ha⁻¹. A traditional control group was not included in this study, as the experimental design focused on direct comparisons between varieties. Our results showed that soil ionic composition played a significant role in shaping microbial activity. Notably, we found that YM-5 treatment exhibited the highest relative soil microbial abundance (22.1%) under the condition of soil amendments. Furthermore, the YM-5 treatment significantly reduced soil Na+ content and exchangeable sodium percentage (ESP) (p < 0.05), outperforming other treatments. Compared to YM-2, the YM-5 treatment also resulted in substantial increases in soil organic carbon (SOC) and available potassium (AK), increases of 78.28% and 54.3%, respectively. In addition to enhancing physicochemical parameters, the integration of switchgrass and amendment promoted soil biological vitality. For example, the YM-2 treatment achieved a 7.4% increase in catalase (CAT) activity and a 6.3% reduction in soil pH compared to YM-3, indicating improved redox balance and acid–base regulation. Collectively, these findings provide direct empirical evidence supporting the effectiveness of switchgrass–amendment combinations in saline–alkali soil restoration. Among the tested cultivars, YM-5 demonstrated superior ecological performance and is recommended as the most suitable genotype for saline–alkali soil amelioration when used in conjunction with coal-based amendments. Full article

The individual application of salt-tolerant plant growth-promoting rhizobacteria (ST-PGPR) or organic amendments exhibits certain limitations in remediating saline-alkali soils. This study developed a co-application treatment by combining a functionally complementary ST-PGPR consortium (Bacillus velezensis and Bacillus marisflavi) with optimized organic amendments (biochar at 22.5 t·ha⁻¹ and sheep-manure organic fertilizer at 7.5 t·ha⁻¹) to enhance soil quality and wheat growth. Compared with the control, the combination of the ST-PGPR consortium with organic amendments significantly reduced soil electrical conductivity by 52.69%. while soil organic matter, alkaline nitrogen, available phosphorus, and available potassium increased by 54.37%, 7.68%, 11.85%, and 39.57%, respectively (p < 0.05). The activities of sucrase, urease, and catalase also increased by 147.69%, 28.56%, and 30.26%, respectively (p < 0.05). Furthermore, the combined treatment significantly promoted wheat growth, increasing plant height, root length, and fresh weight by 12.11%, 26.60%, and 35.00%, respectively (p < 0.05), while alleviating osmotic and oxidative stress. β-diversity analysis revealed distinct microbial community compositions across treatments, and microbial composition indicated that Actinobacteriota and Starmerella were enriched under the co-application. Additionally, the co-application significantly enhanced the complexity and interconnectivity of the bacterial network, while reducing the stability of the fungal network. Partial least squares path and random forest models identified soil chemical properties as the key factors driving wheat growth. This synergistic system presents a promising and sustainable strategy for remediating saline-alkali soils and enhancing crop productivity. Full article

Soil co-contamination with heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) represents a widespread and challenging environmental issue that is difficult to address using conventional remediation methods. This review systematically examines the molecular mechanisms by which plant root exudates mediate the remediation of co-contaminated soils through synergistic interactions with rhizosphere microorganisms. We detail how plants dynamically adjust the composition and secretion of root exudates—such as organic acids, amino acids, sugars, and secondary metabolites—in response to combined HM-PAH stress. These exudates play multifaceted roles in remediation, including chelating HMs, enhancing PAH solubility and bioavailability, and acting as chemoattractants and metabolic substrates for rhizosphere microbes. In return, the recruited microbial communities contribute to pollutant detoxification through various mechanisms, such as biosurfactant production, enzymatic degradation, and improved plant nutrient acquisition. This reciprocal interaction forms a synergistic plant-microbe feedback loop that effectively mitigates combined contamination stress. By integrating evidence from diverse plant–soil systems, this review provides a comprehensive mechanistic framework for understanding root exudate-microbe interactions, offering critical insights for developing enhanced phytoremediation strategies to address complex environmental pollution. Full article

Heavy metal contamination in agricultural soils has emerged as a critical environmental and public health issue associated with increased gastric cancer incidence worldwide. Among the most concerning pollutants are cadmium, arsenic, and lead, which persist in the environment and enter the human body primarily through the soil–plant–food chain. This review integrates environmental, molecular, and epidemiological evidence to explain how these metals alter gastric mucosal biology and promote carcinogenesis. Mechanistically, cadmium, arsenic, and lead trigger oxidative stress, mitochondrial dysfunction, DNA damage, and epigenetic reprogramming, resulting in genomic instability, resistance to programmed cell death, and the transformation of epithelial cells into invasive phenotypes. These molecular disruptions interact with Helicobacter pylori infection, microbial imbalance, chronic inflammation, and hypoxia-driven remodeling of the gastric stroma, all of which enhance angiogenesis and tumor progression. Advanced experimental platforms, such as gastric organoids, immune co-cultures, and humanized animal models, are improving the understanding of these complex interactions. Adopting a One Health perspective reveals the continuity between environmental contamination, agricultural production, and human disease, underscoring the importance of integrative monitoring systems that combine soil and crop analysis with molecular biomarkers in exposed populations. Strengthening this interdisciplinary approach is essential to design preventive strategies, guide remediation policies, and protect human, animals, and environmental health. Full article

The degradation of sandy land in Inner Mongolia presents a substantial threat to regional ecological security and the sustainable development of agriculture and animal husbandry. Planting alfalfa serves as a crucial recovery strategy; however, the inadequate capacity to retain water and nutrients impedes this process. The current reliance on a singular microbial remediation method has demonstrated limited effectiveness in addressing the challenges posed by sandy soil. While traditional sand-fixing agents can improve soil nutrients, they lack biological activity. Furthermore, the synergistic mechanisms between these approaches and their ecological impacts within a single season remain poorly understood. This study involved a pot experiment utilizing wind-sand soil as the substrate to evaluate the soil physicochemical properties, enzyme activities, and microbial community structure associated with the stress resistance of alfalfa. The results indicated that the medium concentration of sand-fixing agent (1:75) exhibited optimal water retention performance, thereby creating a conducive growth microenvironment for Trichoderma longibrachiatum and mitigating fluctuations in surface temperature and humidity. The combined treatment significantly improved the alpha diversity of soil microorganisms, thereby improving the stability and stress resistance of the system. Through the synergistic approach of “sand fixation and water retention–nutrient activation–improved stress resistance”, the microenvironment of sandy land was effectively improved, promoting alfalfa growth. This method offers “environmentally friendly and synergistic” technical support for the efficient cultivation and ecological restoration of alfalfa in sandy regions, while also contributing to the high-quality development of grassland animal husbandry. Full article

Biochar has been demonstrated to be effective in the remediation of heavy metal contamination in soil. However, few studies have examined the impacts of varying proportions of biochar and microbial organic fertilizers on heavy metal adsorption and microbial abundance in soil. Therefore, we investigated the remediation of soil contaminated with heavy metals (Cd and Cu) using different proportions of biochar and microbial organic fertilizer. The results revealed that the adsorption effect of different modifier combinations on heavy metals was notably different, and the metal speciation was significantly altered. Optimal biochar and microbial organic fertilizer combinations significantly reduced the bioavailability and ecological toxicity of heavy metals in the soil, which enhanced plant germination and growth. Furthermore, the addition of modifiers regulated soil pH, preventing root acidification; optimized microbial abundance; enhanced soil microbial environment; and reduced the inhibitory effect of heavy metals on microorganisms. These findings indicate that the addition of amendments may create a virtuous cycle of heavy metal pollutant adsorption, resulting in organic fertilizer efficiency, a better soil environment, and increased crop yield. Full article

Straw return is a potential practice for adsorbing salt and retaining moisture in saline–alkali soils. However, adverse climate conditions such as prolonged drought and cold winters shorten the effective structural turnover of returned straw biomass in soils. Furthermore, the rigid crystalline cell walls and recalcitrant lignin components of undecomposed plant residues lower the adsorption capacity towards salt. Here, we report the pretreatment of neutral oxalic acid to destroy the dense crystalline structure of cotton straw cellulose. Through laboratory experiments, combined with the changes in the structural and chemical properties of cotton straw, the optimal oxalic acid pretreatment (OAC) conditions were determined. Subsequently, the application effectiveness of OAC was evaluated via pot experiments and field trials. The optimal conditions of OAC were 0.2% dosage, 60 °C, and 24 h, displaying a maximum increase in salt absorption and water retention capacities of cotton straw materials, through exposing the hydroxyl network of cellulose and chemically hydrolyzing recalcitrant lignin. In the indoor potted plant experiments, the feasible application of oxalic acid pretreatment can be regarded as an active barrier, increasing soil moisture by 16–43% and reducing total salts by 23–26% in the topsoil (0–20 cm) within a 45-day laboratory incubation. Additionally, the OAC pretreatment had negligible adverse impacts on soil microbial communities. Moreover, some plant-beneficial microbes (e.g., Sphingomonadaceae and Gemmatimonadaceae) were stimulated, with their relative abundance increasing by 26–40% and 27–63%, respectively. Ultimately, under the pretreatment of oxalic acid-modified cotton straw salt-absorbing water-retention agent (OAC-SR), cotton seedling emergence rates, plant height, and biomass all increased to varying degrees across different concentrations of saline–alkali soil (0.05–1.0%) in the field. Then OAC-SR can be potentially applied to the process of cotton straw return to facilitate the turnover of straw structure in soil, enhance the salt-adsorption and water-retention capacities of returned straw, and provide a low-salt microenvironment for crop growth. This study demonstrates a further low-carbon and in situ applicable route to accelerate the destruction of cotton straw structure, thereby alleviating crop salt damage and promoting the green circular development of saline–alkali soil remediation. Full article

This study evaluated the individual and combined effects of different bio-inputs—traditional filter cake, filter cake composted with ash, and a microbial inoculant—on the growth and physiological performance of Mucuna pruriens cultivated in soil contaminated with the herbicide tebuthiuron. The experiment followed a completely randomized design with twelve treatments and five evaluation periods (7, 21, 35, 49, and 70 days after sowing). Morphophysiological variables such as plant height, root length, dry biomass, and chlorophyll content were assessed. The results showed that the addition of traditional filter cake promoted significant growth in tebuthiuron-contaminated soil, while, in uncontaminated conditions, both organic residues and the microbial inoculant enhanced plant development, particularly at later stages. Initial phytotoxicity was observed in treatments with organic residues (up to 67% of samples before 35 days), but these effects decreased over time. The microbial inoculant performed better in the absence of organic amendments, suggesting possible antagonistic interactions. Tebuthiuron reduced chlorophyll content by inhibiting photosystem II, but this effect was mitigated by the addition of filter cake. Overall, the findings highlight the potential of integrating Mucuna pruriens cultivation with organic residues and microbial inoculants as an effective phytomanagement strategy for tebuthiuron-affected soils. This approach provides a sustainable model for improving soil health, supporting legume-based rehabilitation, and advancing biological alternatives to conventional remediation practices. Full article

Heavy metal (HM) contamination in agricultural soils poses a significant threat to soil health and plant productivity. This study investigates the impact of cadmium (Cd) and zinc (Zn) stress on tomato plants (Solanum lycopersicum) and explores the mitigation potential of microbial biostimulants (MBs), including arbuscular mycorrhizal fungi (AMF) and Pseudomonas fluorescens So_08 (PGPR), over a 52-day period using multi-omics approaches. Root exudate profiling revealed distinct metabolic changes under HM stress, which compromised soil–plant interactions. Cd stress reduced the secretion of phenylpropanoids (sum LogFC: −45.18), lipids (sum LogFC: −27.67), and isoprenoids (sum LogFC: −11–67), key metabolites in antioxidative defense, while also suppressing rhizosphere fungal populations. Conversely, Zn stress enhanced lipid exudation (such as sphingolipids and sterols, as sum LogFC of 8.72 and 9.99, respectively) to maintain membrane integrity and reshaped rhizobacterial communities. The MBs application mitigated HM-induced stress by enhancing specialized metabolite syntheses, including cinnamic acids, terpenoids, and flavonoids, which promoted crop resilience. MBs also reshaped microbial diversity, fostering beneficial species like Portibacter spp., Alkalitalea saponilacus under Cd stress, and stimulating rhizobacteria like Aggregatilinea spp. under Zn stress. Specifically, under Cd stress, bacterial diversity remained relatively stable, suggesting their resilience to Cd. However, fungal communities exhibited greater sensitivity, with a decline in diversity in Cd-treated soils and partial recovery when MBs were applied. Conversely, Zn stress caused decline in bacterial α-diversity, while fungal diversity was maintained, indicating that Zn acts as an ecological filter that suppresses sensitive bacterial taxa and favors Zn-tolerant fungal species. Multi-omics data integration combined with network analysis highlighted key features associated with improved nutrient availability and reduced HM toxicity under MB treatments, including metabolites and microbial taxa linked to sulfur cycling, nitrogen metabolism, and iron reduction pathways. These findings demonstrate that MBs can modulate plant metabolic responses and restore rhizosphere microbial communities under Cd and Zn stress, with PGPR showing broader metabolomic recovery effects and AMF influencing specific metabolite pathways. This study provides new insights into plant–microbe interactions in HM-contaminated environments, supporting the potential application of biostimulants for sustainable soil remediation and plant health improvement. Full article

Cadmium (Cd) contamination in agricultural soils originates mainly from atmospheric deposition, irrigation water, fertilizers, pesticides, and industrial waste discharges. This human-induced pollution adversely affects soil fertility and structure, disrupts plant growth and physiological activities, and poses severe health risks through food-chain accumulation. Despite increasing research attention, comprehensive assessments that integrate global patterns, remediation strategies, and knowledge gaps remain limited. Therefore, this literature review critically synthesizes findings from 1060 peer-reviewed studies (screened using PRISMA guidelines) retrieved from Scopus and Web of Science databases, focusing on Cd sources, environmental behavior, plant responses, and soil remediation techniques. Results show that most research has been concentrated in Asia—particularly China—and Latin America. The most frequently investigated topics include Cd accumulation in crops, soil amendments, phytoremediation, and microbial-assisted remediation. Among remediation strategies, assisted phytoremediation and integrated biological–chemical approaches (biochar, PGPR, and soil amendments) emerged as the most promising for sustainable Cd mitigation. In conclusion, this review highlights regional disparities in research coverage, emphasizes the effectiveness of combined remediation approaches, and identifies the need for interdisciplinary and field-scale studies to advance sustainable solutions for Cd pollution control in agricultural systems. Full article