Search Results (9,413)

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

Several species of saprophytic filamentous fungi are able of disrupting the life cycle of certain soil-born parasites that are of veterinary and agronomy importance, offering a promising sustainable control alternative. This study consisted of designing an experimental model, using catnip (Nepeta cataria) trays to simulate a vegetated environment for evaluating the parasiticidal activity of Mucor circinelloides, Trichoderma atrobrunneum, and Duddingtonia flagrans. Fungal spores were added to treated trays before adding feces with protozoan (Eimeria spp.), and gastrointestinal nematodes (roundworms, strongyles), and untreated-control water. No differences in plant growth or vigor, regardless of fungal presence, were observed, confirming the safety of these biological agents for vegetation. In the control trays, the viability of parasites ranged from 50% to 85%. In the treated trays, the viability of Eimeria and roundworms decreased by 40–100%, and the strongyle egg counts were reduced by 74% within 15 days. It is concluded that the vegetated tray model effectively simulates field conditions and provides a reliable platform for evaluating fungal efficacy against the free-living stages of parasites, offering a versatile tool for future research on soil-borne pathogens affecting animals and plants. Full article

Municipal solid waste management remains a major environmental challenge across Africa, where rapid urbanisation has outpaced formal waste infrastructure and routine landfill monitoring is often absent. Rather than proposing a classification algorithm, this study investigates whether spaceborne hyperspectral imagery can reveal robust spectral fingerprints of landfill surfaces suitable for automated detection. Eight landfill sites across seven African countries were analysed using Hyperspectral Imager Suite (HISUI) data (400–2500 nm, 20 m resolution). A segment-based framework was applied after masking low signal-to-noise regions, combining brightness analysis, L2-normalised spectral shape comparison using Spectral Contrast Angle (SCA), and derivative spectroscopy across 109,275 pixels from six land-cover classes. Brightness-based discrimination exhibited strong inter-site variability, limiting its general applicability. In contrast, shape-based metrices revealed consistent separability between landfill-active surfaces and soil or urban classes in the shortwave infrared (SWIR), particularly within the 1538–1750 nm and 2075–2474 nm regions. Derivative analysis further identified stable extrema near approximately 1700 nm and 2200–2300 nm across all sites, indicating reproducible curvature-based fingerprints associated with exposed municipal solid waste. These results demonstrate that landfill surfaces exhibit intrinsic SWIR spectral characteristics that persist across diverse African environments. This study establishes the first multi-site hyperspectral library of African landfill surfaces, providing a physical basis for developing generalised landfill detection frameworks. Full article

This study investigates the challenging task of predicting the strength of subgrade soils, which serve as the foundation of superstructure systems. Due to the inherent complexity of soil behavior, traditional empirical methods often fall short in providing consistent and reliable estimations. To address this limitation, a fuzzy entropy-based TOPSIS multi-criteria decision-making (MCDM) approach is proposed. Methodologically, the study introduces a novel fuzzy entropy function that extends existing fuzzy entropy formulations and is compared against conventional fuzzy entropy measures. Using the newly proposed $P_m^{-}$ fuzzy entropy (m = 0.5), a soil stabilization quality ranking was obtained and validated against classical fuzzy entropy-based TOPSIS results. It is important to emphasize that the primary objective of the proposed framework is not to provide direct numerical estimates of CBR values, but rather to support the decision-making process by ranking soil options based on multiple criteria under conditions of uncertainty. The robustness of the rankings was further examined using California Bearing Ratio (CBR) data and comprehensive sensitivity analyses to consider uncertainties from expert judgments and laboratory measurements. The proposed approach offers a solution for multi-criteria decision-making processes in uncertain environments, ensuring high rating consistency and adaptability. Full article

Phytoremediation is one of the most widely used techniques for the removal of heavy metal pollutants from soil. This investigation explored the effect of soil co-contamination on Cd accumulation levels in hemp. To this end, a series of experiments were carried out on Cd-contaminated Mediterranean soils, which were subsequently contaminated with different levels of additional metals (Zn, Cu and their combination). The amount of Cd accumulated in hemp plants grown in the mono- and multi-contaminated soils was determined in each case, along with the Cd distribution in the different plant parts. The results showed that Cd accumulated mainly in the roots of hemp plants, regardless of the presence or absence of Cu and Zn. Co-contamination with Zn at moderate levels resulted in antagonistic effects on Cd uptake, whereas higher Zn concentrations increased hemp’s Cd accumulation capacity. On the other hand, Cu presence resulted in a synergistic increase in Cd uptake, notably at higher levels of contamination. Both Cu and Zn presence did not significantly alter Cd accumulation patterns, suggesting that hemp remains a sustainable candidate for phytoremediation in multi-metal contaminated soils. These findings provide valuable insights regarding the potential of hemp for soil remediation, highlighting its suitability for Cd-contaminated soils, even in complex contaminated environments. In light of the ongoing accumulation of heavy metals in soil environments, the implementation of cost-effective and environmentally sustainable remediation strategies is becoming increasingly necessary and can be regarded as essential. Full article

Soil salinization in arid oases constrains soil functioning and crop production, making spatially explicit monitoring important for land management. Multispectral optical remote sensing enables large-area salinity assessment, but in oasis environments such as the Keriya Oasis, its performance can be limited by spectral confusion between salt crusts and bright bare soils, sparse vegetation cover, and strong surface heterogeneity. Synthetic aperture radar (SAR), by contrast, provides all-weather imaging capability and sensitivity to surface scattering and dielectric-related conditions, but its salinity interpretation is often affected by surface complexity and environmental coupling. To address these, a spectral index–polarimetric scattering integration framework that combines RADARSAT-2 and Landsat-8 OLI features within a simple two-dimensional (2D) feature space was developed. Two groups of models were constructed from variables selected through a data-driven screening process: (1) polarimetric feature space models based on combinations such as VanZyl volume scattering with Pauli odd-bounce or Touzi alpha scattering; and (2) multi-source feature space models that integrate the optimal polarimetric component with key spectral indicators such as SI4 and MSAVI. Among all tested models, VanZyl_vol-SI4 achieved the best performance (fitting: R² = 0.749, RMSE = 5.798 dS m⁻¹, MAE = 4.086 dS m⁻¹; validation: R² = 0.716, RMSE = 5.566 dS m⁻¹, MAE = 4.528 dS m⁻¹). The results indicate that integrating PolSAR scattering information with optical indices can improve salinity mapping relative to single-source feature spaces in the Keriya Oasis. The proposed 2D framework provides a concise way to compare different feature combinations and supports regional identification of salt-affected soils. Full article

Soil contamination by heavy metals and organic pollutants presents significant challenges to the global environment and public health. However, a lack of micro-scale understanding of the pollution process hinders efforts to remediate and enhance soil quality. Synchrotron-based X-ray imaging and spectroscopy techniques are powerful tools in revealing complex interactions within heterogeneous soil systems. This review systematically explores recent advances in soil research that deepen our knowledge on the chemical states, spatial distribution, and dynamic interactions of heavy metals and organic contaminants via synchrotron-based techniques (e.g., micro-XRF imaging, FTIR, SR-μCT). It highlights the potential of these methods to characterize composition, aggregate structure, and microbial activity within soil matrices with high spatial and temporal resolution, in situ, and with element-specific analysis. Additionally, a forward-looking perspective outlines key research directions to leverage these advantages and develop more effective and sustainable soil restoration strategies. We hope this work emphasizes the role of synchrotron science in field-scale soil applications and inspires future, mechanism-driven, evidence-based soil remediation efforts. Full article

Soil erosion in mountain environments is governed by the interaction of climatic drivers, surface conditions, and geomorphic connectivity. Recently, disturbance by large herbivores has been recognized as a potentially important but poorly quantified geomorphic driver. However, the combined effects of freeze–thaw processes and ungulate disturbance on sediment production remain unclear. This study provides quantitative field-based evidence linking deer activity to hillslope sediment flux in a montane forest catchment in central Japan. A six-year dataset (2019–2025), including climatic conditions, deer detections from camera traps, understory vegetation cover, and hillslope sediment flux (<9.5 mm) was analyzed. Multiple regression analysis was conducted using daily sediment flux as the response variable and maximum 1 h rainfall, freeze–thaw frequency, and daily deer detections as explanatory variables. The results showed that deer detections had a significant positive effect on sediment flux, whereas rainfall intensity and freeze–thaw frequency did not exhibit strong independent effects. Particle-size analysis further indicated that eroded sediment was markedly coarser than the surface soil, suggesting that short-term climatic drivers alone did not control sediment transport. These findings demonstrate that biotic disturbance by large herbivores can play a dominant role in hillslope sediment flux under cold, high-elevation conditions by modifying surface conditions and sediment connectivity. From a sustainability perspective, these results highlight the importance of managing deer populations to maintain ecosystem stability, prevent land degradation, and support sustainable forest and watershed management under changing environmental conditions. Full article

Using density functional theory (DFT) and the Gaussian 09 program, the study calculated Gibbs free energy to understand how easily each NP can transform. Results showed that only 2,6-dinitrophenol (2,6-DNP) and 2-chloro-6-nitrophenol (2-Cl-6-NP) had Gibbs free energies above 0 kJ/mol. The study also evaluated the toxicity of the NPs, leading to the identification of trinitrophenol (TNP), 2-chloro-4-nitrophenol (2-Cl-4-NP), and 2-nitrophenol (2-NP) with the highest risk scores. In the present study, binding energies were used only as comparative indicators of enzyme–substrate interaction favorability within a screening framework, rather than direct measures of catalytic degradation efficiency. The enzyme 1,2-dioxygenase from Acinetobacter baylyi ADP1 showed strong degradation effects on catechol, with significant binding energies for 2-NP, 2-Cl-4-NP, and TNP. The PS-AOP changed the degradation environment, which reduced enzymatic efficiency. The study also modified specific amino acids in enzymes to improve their performance. For example, the enzyme 1DLT-6 had a degradation increase of nearly 27% compared to the reference enzyme. Finally, we tried to measure the impact of different forces on the breakdown of nitrophenols by enzymes. We used a two-dimensional amino acid map based on enzyme–ligand interactions and a visualization of non-covalent interactions. Our findings show that van der Waals forces and electrostatic forces are the main factors affecting how well the material breaks down. From a sustainability perspective, the study highlights a promising strategy for mitigating secondary pollution, improving the environmental compatibility of PS-AOP-based remediation, and supporting safer and more sustainable restoration of petroleum hydrocarbon-contaminated soil and groundwater. These findings help strengthen the theoretical basis for developing greener post-oxidation remediation pathways. Full article

Mercury (Hg) is a ubiquitous element in the environment that may pose a threat to human health due to its toxicity, high mobility through the food chain, and long-lasting persistence. Organic Hg compounds, particularly methylmercury, are more toxic than inorganic mercury due to their easy absorption and persistent retention within the organism. Although natural attenuation can occur in soil through various processes, excessive levels of Hg cause pollution that can adversely affect agricultural soil, making remediation necessary to either remove or stabilize Hg within the soil. This review primarily aims to summarize key remediation strategies—chemical, biological, and physical—developed in recent years for agricultural soil remediation. It discusses the influencing factors, advantages, limitations, mechanisms, and practical applications of these soil remediation technologies. The published literature focuses on identifying plant species and microorganisms capable of remediating Hg-contaminated soils. Emerging amendments, such as biochar and nanomaterials, have been tested for treating mercury (Hg)-polluted soils primarily by immobilizing mercury and reducing its bioavailability and methylation. Ex situ remediation technologies are effective for Hg-contaminated soils but are often costly, labor-intensive, detrimental to soil quality, and generate hazardous secondary waste. In contrast, in situ technologies treat Hg directly within the soil, preserving the soil matrix and its biota. According to the literature, remediation of Hg-contaminated agricultural soils can be compatible with food crop production only if the bioavailable Hg fraction is sufficiently reduced and crop uptake remains below food safety limits. The gap between laboratory trials and actual field applications in Hg-contaminated soil remediation mainly arises from differences in scale, complexity, and the uncertainty of real-world conditions, which often reduce the efficiency and predictability of treatments. This review aims to provide a practical reference for improving the effective remediation of Hg-contaminated soils in the future. Full article

The textile industry wastewater contaminated by azo dyes usually contains a certain amount of salinity. Therefore, screening for microorganisms capable of degrading azo dyes in saline environments is of great significance. In this study, the decolorizing activity of azo dye methyl red (MR) by Klebsiella aerogenes WH2 (WH2), newly isolated from soil, was evaluated. WH2 was able to decolorize 92.4% and 86.0% of MR at concentrations of 200 mg/L and 300 mg/L within 24 h, respectively. Given that WH2 exhibited enhanced growth and superior degradation capacity in the presence of 2.5% NaCl compared to salt-free conditions, it can be classified as a slight halophile. Approximately 87.7% of MR was removed by WH2 in the presence of 10.0% NaCl within 24 h. Azoreductase activity assays indicated that WH2 retained higher enzyme activity in the presence of NaCl concentrations not exceeding 7.5%. The degradation products and putative metabolic pathways for MR degradation by WH2 were analyzed using FTIR and LC-MS. Phytotoxicity analysis based on seed germination of Vigna radiata indicated that the degradation products of MR exhibited less toxicity than the parent compound. The high degradation efficiency of MR under high salt concentrations makes WH2 a promising candidate for the treatment of saline textile wastewater. Full article

Ecological restoration—whether active or passive—includes forest development, forest rehabilitation, and a range of other activities that contribute to ecosystem services. To provide a formal framework, we hypothesized how does reforestation (through different forestry practices) affect the conservation of soil functionality? That is, how does reforestation/afforestation/forest restoration improve soil quality? And, specifically, how do they improve physical properties (such as structural stability, infiltration) and chemical properties (such as acidity, electrical conductivity)? For this purpose, we conducted a bibliometric analysis review of the peer-reviewed scientific literature and research reports of numerous articles in order to compile a large database of forest restoration studies, with an emphasis on the Mediterranean region. The final focus was to obtain conclusions about how it affects soil quality. Overall, our examination confirms that deforestation drives a decline in soil carbon and nitrogen, subsequently impairing microbial activity. Consequently, forest removal frequently leads to accelerated erosion, nutrient depletion, and compaction. In contrast, reforestation acts as a critical intervention, stabilizing soil structure, reestablishing fertility, and enhancing soil quality overall. Additionally, three case studies are synthetically presented concerning the short-, medium-, and long-term results of forest restoration projects carried out mainly in central and northern Spain. These cases corroborate the significant role of forest restoration in the control and enhancement of ecosystem services, particularly in relation to soil improvement, the enhancement of hydrological regulation processes within watersheds (runoff, infiltration, erosion), landscape amelioration, and the socio-economic aspects of rural environments. Ultimately, forest restoration is established as a necessary and essential practice in ecological restoration efforts to counteract the impacts of anthropogenic activities. Full article

Plants of the genus Opuntia are cacti that grow under natural conditions, with scarce humidity, drastic changes in daytime and nighttime temperatures, and poor soils. Their fruits are a food source in certain regions of the world, and their modified stems (cladodes) have diverse uses, including human consumption—especially when young, tender, and succulent (“nopalitos”) —livestock feed, and raw material for various products. There are approximately 300 species and dozens of variants of this genus, identified as wild, semi-domesticated, or domesticated. The physiological and biochemical responses to abiotic stress in these species are diverse but are related to their Crassulacean acid metabolism and the level of domestication. The morphological modifications in fruits, seeds, and cladodes of the genus Opuntia during domestication appear to be the sum of numerous significant biochemical-physiological changes, but generally of small magnitude. Thus, evaluating wild, semi-domesticated, and domesticated Opuntia species allows us to understand the physiological and biochemical processes along a natural gradient (original and modified by natural and artificial selection and by the cultivation environment) and their alteration by abiotic stress of any kind. This review summarizes our main advances in considering the genus Opuntia as a model for evaluating abiotic stress in the physiology and biochemistry of succulent plants. Furthermore, it shows high relevance, especially in the context of climate change, because Opuntia species are key to food security in arid zones. Full article

Archeological sites in humid regions are particularly susceptible to mechanical degradation induced by rainfall-driven wet–dry (W-D) cycles after excavation. In this study, representative archeological soils from the Suzhou region were investigated to quantify strength attenuation and pore structure evolution under cyclic moisture disturbance. Laboratory W-D cycling tests were conducted on samples prepared using static compaction and layered compaction methods, with cycle numbers up to nine and cycle amplitudes of 1–4 days. Unconfined compressive strength (UCS), direct shear strength, scanning electron microscopy, and mercury intrusion porosimetry were used for multiscale characterization. Results show that UCS decreases by approximately 40–50% after six to nine W-D cycles, accompanied by a porosity increase of 4.0–5.5% for statically compacted samples and 6.5–8.0% for layered-compacted samples. Layered-compacted specimens exhibit an average strength reduction of about 20% within the first three cycles, significantly higher than that of statically compacted soils. Microstructural observations reveal a progressive transformation from micropore-dominated structures (<10 μm, initially 70–80%) to interconnected meso- and macropores (>50 μm, up to 30–40%), leading to increased permeability (from ~10⁻⁸ to 10⁻⁶ cm/s). A semi-empirical model incorporating cycle number and amplitude successfully captures the non-linear evolution of porosity and strength degradation. These findings provide quantitative criteria for assessing excavation stability and long-term deterioration risks of archeological sites in humid environments. Full article

Deep-buried tunnels in urban environments require careful evaluation of their long-term interactions with the surrounding ground to ensure structural safety and sustainability. Taking the Beijing Eastern Sixth Ring Road renovation project as a case study, this research employs a fully coupled fluid–solid numerical approach to elucidate the long-term disturbance mechanisms associated with deep-buried shield tunneling. Specifically, the research quantifies spatio-temporal ground responses and characterizes the consolidation settlement mechanisms exacerbated by potential tunnel leakage. The results indicate that ground deformation is primarily governed by the intensity of tunnel leakage. When the waterproofing grade of the tunnel meets Grade I or II, leakage and surface settlement remain negligible. However, when a tunnel’s waterproofing grade deteriorates to Grade IV or lower, consolidation settlement increases significantly, becoming the dominant deformation mode. In addition, both the extent and severity of ground movement are highly sensitive to the geometrical boundaries of the strata and the relative depth of the tunnel. Larger permeable domains and deeper tunnels lead to wider pore pressure and stress disturbance zones, ultimately leading to more pronounced long-term settlement. Furthermore, soil permeability dictates the temporal evolution of the ground response, with poorly permeable layers exhibiting delayed fluid–solid re-equilibration. A critical threshold is observed when leakage rates align with or exceed the soil’s permeability, leading to a significant escalation in both the amplitude of subsidence and the time required to reach equilibrium. These findings offer valuable insights for the design, waterproofing, and long-term management of deep urban tunnels. Full article