Search Results (1,316)

Arbuscular mycorrhizal fungi (AMF) form symbiotic interactions with most terrestrial plants, enhancing nutrient uptake and stress resilience. Organic amendments like biochar, compost, and manure are advocated to improve soil health and promote AMF symbiosis. However, empirical evidence of their effects on root AMF colonization is inconsistent, and a systematic understanding of the governing factors is lacking. Here, we synthesized the responses of root AMF colonization in agricultural systems to biochar, compost, and manure input from 85 studies (663 pairs of observations) globally based on a meta-analysis. Overall, biochar and compost/manure significantly increased root AMF colonization. However, these effects were highly context-dependent. Biochar most strongly promoted colonization in coarse-textured soils with low total potassium (TK ≤ 25 g kg⁻¹) and high total carbon (TC ≥ 11 g kg⁻¹), particularly for fruit and tuber crops. In contrast, compost/manure were most effective in fine-textured soils with high TK (≥25 g kg⁻¹) and low bulk density (BD ≤ 1.3 g cm⁻³). Notably, compost/manure suppressed colonization in neutral pH (6.5 < pH < 7.5) and high BD soils (>1.3 g cm⁻³). Key amendment properties drove these responses: biochar with low electrical conductivity (EC < 5 dS m⁻¹), high sodium and low macronutrient content was most beneficial, whereas compost/manure with high total nitrogen (TN > 9 g kg⁻¹) and low organic carbon (OC ≤ 500 g kg⁻¹) performed best. The efficacy of organic amendments in enhancing AMF symbiosis is not universal but dictated by a complex interplay of soil properties and amendment characteristics. Our findings provide a robust, quantitative framework for tailoring amendment strategies to specific agro-ecological contexts, enabling farmers and land managers to selectively use biochar or compost/manure to harness AMF benefits for sustainable crop production. Full article

In southwest China, vegetation restoration is widely used in karst rocky desertification control projects. However, mechanistic evidence explaining how plant community composition and species diversity regulate cadmium (Cd) bioavailability remains limited. Here, the plant community’s species diversity, soil properties, Cd, and available Cd contents were evaluated. Four plant community types, NR (natural recovery), PMC (Pistacia weinmannifolia + Medicago sativa + Chrysopogon zizanioides), and PME (Pistacia weinmannifolia + Medicago sativa + Eragrostis curvula), were selected as the research objects. The species composition was recorded, and dominant plant species and soil samples were collected to analyze Cd accumulation characteristics. Relative to NR, composite restorations increased plant diversity and soil nutrient availability and reduced soil compaction, with PMC showing the strongest remediation, decreasing total Cd by 49.4% and available Cd by 59.5%. Model-averaged regression and hierarchical partitioning analyses further identified nitrogen availability and community structure as the dominant drivers. Specifically, available nitrogen (AN), vegetation coverage, Margalef species richness (DMG), ammonium nitrogen (NH₄⁺–N), and total N (TN) were the main factors of soil total Cd, and BD, TN, nitrate nitrogen (NO₃⁻–N), mean crown diameter (MCD), and Shannon–Wiener index (H′) were the main factors of soil available Cd. The results indicate that PMC provides a plant community structure configuration decisions of a scalable, site-adaptable strategy for durable Cd stabilization and soil conservation in thin, carbonate-rich karst soils. Full article

The electrical resistivity and acoustic properties of marine sediments are essential for understanding their physical and mechanical behavior. Over recent decades, significant advancements have been made in both in situ and laboratory measurement techniques, alongside theoretical models, to establish correlations between these geophysical parameters and sediment properties such as porosity, saturation, and consolidation degree. However, a comprehensive comparison of the advantages, limitations, and applicability of different measurement methods remains underexplored, particularly in complex scenarios such as gas hydrate-bearing sediments. This review provides an in-depth synthesis of recent developments in in situ and laboratory testing technologies for assessing the resistivity and acoustic characteristics of marine sediments. Special emphasis is placed on the latest advances in acoustic measurements during gas hydrate formation and decomposition. The review highlights key challenges, including (1) limited vertical resolution in in situ resistivity measurements due to probe geometry; (2) errors arising from electrode polarization and poor soil–electrode contact; and (3) discrepancies in theoretical models linking geophysical parameters to sediment properties. To address these challenges, future research directions are proposed, focusing on optimizing electrode array designs for high-resolution resistivity measurements and developing non-destructive acoustic techniques for deep-sea sediments. This work offers a critical reference for marine geophysics and offshore engineering researchers, aiding the selection and development of testing technologies for effective marine sediment characterization. Full article

This study examined long-term changes in soil carbon stock dynamics 11 and 19 years after fire under different severities at 0–5 and 0–25 cm depths with a digital soil mapping approach. Linear (MLR) and non-linear models (RF, SVR, XGBoost) combined with feature selection methods (r < 0.8, FFS, Boruta) were used to predict bulk density (BD), total C, and C stock. Distributional biases were evaluated with Kolmogorov–Smirnov statistics and corrected by Quantile Mapping (QM). RF-FFS performed best for BD and total C at 0–5, while RF-SVR outperformed for C stock and all properties at 0–25. Total C was 49% higher at 0–5, whereas C stock was 7.57 times greater at 0–25. Both models underestimated variability, especially for C stock. At 0–25, bulk density decreased after fire, particularly under conditions of medium severity, while total C increased following the same tendency. The results showed that fire’s legacy is still present in the ecosystem after one and two decades. This is particularly evident at greater depths, where long-term C stock is lower. Full article

The long-term effects of integrated nutrient management (INM) on crop performance and soil health—particularly within sub-humid environments—remain insufficiently explored. This research aimed to quantify the relationship between the soil quality index (SQI) and overall system productivity. The SQI represents a numerical indicator of soil functioning and its biological and chemical integrity, while system productivity reflects the economic yield generated by the cropping system. A long-term experiment initiated in 1972 formed the foundation for this study, which was conducted from 2019 to 2021 and included eleven nutrient management treatments. These comprised the following treatments: inorganic fertilizers alone (100% NPK, 150% NPK, 100% NP, 100% N, and 100% NPK without sulfur); combinations of organic and inorganic inputs (50% NPK + FYM and 100% NPK + FYM); lime with inorganic fertilizers (100% NPK + lime); zinc with inorganics (100% NPK + Zn); hand weeding with inorganics (100% NPK + HW); an unfertilized control. The study was implemented in a maize–wheat rotation under the sub-humid climatic conditions of Palampur, Himachal Pradesh, India. System productivity was estimated using wheat grain equivalent yield, and SQI values were generated from selected soil properties. These indicators—along with the sustainable yield index (SYI)—were applied to assess the effectiveness of each treatment. The results showed that the 100% NPK + FYM combination produced the highest SQI, followed by 100% NPK + lime, whereas the 100% N treatment yielded the lowest value. Overall, the findings highlight the crucial role of adopting sustainable nutrient management practices to maintain soil quality and optimize productivity in sub-humid agricultural systems. Full article

Contamination of water and soil with a wide range of pollutants, including pesticides, pharmaceuticals, and industrial chemicals, remains a significant environmental challenge. Carbon-based materials are widely recognized for their high adsorption capacity, chemical stability, and the possibility to tailor their surface and structural properties. In recent years, ionic liquids (ILs) have been explored as useful media and functionalization agents in the preparation of such materials. Their unique physicochemical properties can facilitate activation, influence pore structure, and introduce specific functional groups that improve interactions with target contaminants. This review summarizes recent developments in the use of ILs for the synthesis, modification, and regeneration of carbonaceous adsorbents. Particular attention is given to IL-assisted activation techniques, surface functionalization strategies, and reported improvements in adsorption performance. Key challenges, such as the environmental impact and cost of ILs, as well as prospects for developing more sustainable IL-based processes, are also discussed. Taken together, these findings highlight the relevance of IL-enabled carbon materials for practical adsorption processes, including water and wastewater treatment, selective pollutant removal, and regeneration-driven purification systems. Full article

To investigate the effects of different Trichosanthes kirilowii Maxim. varieties on leaf nutrients, soil nutrients, and microbial community composition, this study selected Yuelou No. 3 and Huiji No. 2, two major cultivars from the primary production area of Shishou City. The two varieties were cultivated at different locations under standardized agronomic management practices, and a systematic comparative analysis was carried out over a 10-month sampling period from March to December 2024. The analysis encompassed their leaf nutrients (total nitrogen, total phosphorus, total potassium, and relative chlorophyll content), soil nutrients (organic matter, alkali-hydrolyzable nitrogen, available phosphorus, and available potassium), and microbial community characteristics. The results revealed significant varietal differences in leaf nutrient content: the average total phosphorus content of Yuelou No. 3 (0.44%) was higher than that of Huiji No. 2 (0.39%), while Huiji No. 2 exhibited higher total nitrogen (3.73%), total potassium (3.86%), and SPAD (44.72). Leaf nutrient content in both varieties followed a pattern of nitrogen > potassium > phosphorus, with peak phosphorus and potassium demand occurring earlier in Yuelou No. 3. Additionally, Yuelou No. 3 contained higher organic matter (12.73 g/kg) and alkali-hydrolyzable nitrogen (103.02 mg/kg), while Huiji No. 2 showed enhanced soil pH (7.02), available phosphorus (6.96 mg/kg), and available potassium (180.00 mg/kg). Soil available nutrient dynamics displayed a pattern of slow change during the early stage, a rapid increase during the middle stage, and stabilization in the later stage. Microbial analysis revealed no significant differences in alpha diversity between the two varieties, although Yuelou No. 3 showed marginally higher diversity indices during early to mid-growth stages. In contrast, beta diversity showed significant separation in PCoA space. Proteobacteria, Acidobacteria, and Ascomycota were the dominant microbial phyla. Dominant genera included Kaistobacter, Mortierella, and Neocosmospora, among others, with variety-specific relative abundances. Redundancy analysis further supported the variety-specific influence of soil physicochemical properties on microbial community structure, with available phosphorus, available potassium, and alkali-hydrolyzable nitrogen identified as key factors shaping community composition. This study provides a theoretical basis for understanding the impact of different Trichosanthes kirilowii Maxim. varieties on soil–plant–microbe interactions and suggests potential directions for future research on fertilization and management strategies tailored to varietal differences. Full article

Sustainable food production for a growing population requires farming practices that reduce chemical inputs while maintaining soil as a living, renewable foundation for productivity. This review synthesizes current advances in understanding how endophytic fungi (EFs) interact with the soil microbiome and contribute to the physicochemical and biological dimensions of soil health in arable ecosystems. We examine evidence showing that EFs enhance plant nutrition through phosphate solubilization, siderophore-mediated micronutrient acquisition, and improved nitrogen use efficiency while also modulating plant hormones and stress-responsive pathways. EFs further increase crop resilience to drought, salinity, and heat; suppress pathogens; and influence key soil properties including aggregation, organic matter turnover, and microbial network stability. Recent integration of multi-omics, metabolomics, and community-level analyses has shifted the field from descriptive surveys toward mechanistic insight, revealing how EFs regulate nutrient cycling and remodel rhizosphere communities toward disease-suppressive and nutrient-efficient states. A central contribution of this review is the linkage of EF-mediated plant functions with soil microbiome dynamics and soil structural processes framed within a translational pipeline encompassing strain selection, formulation, delivery, and field scale monitoring. We also highlight current challenges, including context-dependent performance, competition with native microbiota, and formulation and deployment constraints that limit consistent outcomes under field conditions. By bridging microbial ecology with agronomy, this review positions EFs as biocontrol agents, biofertilizers, and ecosystem engineers with strong potential for resilient, low-input, and climate-adaptive cropping systems. Full article

The Wenchang Oilfield’s high-porosity and high-permeability reservoirs are planned to be developed using synthetic-based drilling fluids. However, the induced reservoir damage problems caused by existing synthetic-based drilling fluids in high-porosity and high-permeability reservoirs are still unclear. Currently, through the analysis of reservoir core porosity and permeability characteristics, physical and chemical property analysis, reservoir sensitivity evaluation, and solid-phase and filtrate invasion experiments, the mechanism of reservoir damage is systematically explored, and a synthetic-based drilling fluid specifically for high-porosity and high-permeability reservoirs is developed to reduce reservoir damage. The results show that the average pore radius of this reservoir is 29.4 μm, with well-developed pores and strong permeability; the mineral composition is mainly quartz (with an average content of 55.6%), and the clay mineral content is 21.5%. It has water-sensitive, salt-sensitive, and stress-sensitive damage characteristics. Filter fluid invasion and solid-phase blockage are the core factors causing reservoir damage. Based on its damage mechanism, through the optimization of the plug-forming agent formula and the selection of a sealing agent, a low-harm synthetic-based drilling fluid (hereinafter referred to as KS-9) was developed. Performance evaluation shows that the KS-9 drilling fluid maintains stable rheology after 110 °C/16 h thermal rolling, with an upper temperature limit of 150 °C, and can resist 10% NaCl, 1% CaCl₂, and 8% inferior soil pollution; in the core contamination experiment, its static permeability recovery value exceeds 88%, and it has good reservoir protection performance, which can provide technical support for the safe drilling and completion of high-porosity and high-permeability reservoirs in the Wenchang Oilfield. Full article

This study evaluates the performance of single concrete-filled frictional Fibre-Reinforced Polymer (FRP) piles embedded in saturated liquefiable sand and subjected to seismic loading using a shaking table. A unidirectional shaking table equipped with a 1000 mm × 1000 mm × 1000 mm laminar shear box with 27 lamina rings was utilized in the study. FRP tubes manufactured from epoxy-saturated Carbon Fibre-Reinforced Polymer (CFRP) and Glass Fibre-Reinforced Polymer (GFRP) fabrics were filled with 35 MPa concrete and allowed to cure for 28 days, serving as model piles for the experimental programme, with cylindrical concrete prisms employed to represent the behaviour of traditional piles. Pile dimensions and properties based on scaling relationships were selected to account for the nonlinear nature of soil–pile systems under seismic loading. Scaled versions of ground motions from the 2010 Val-des-Bois and 1995 Hyogo-Ken Nambu earthquakes were implemented as input motions in the tests. The results show limited variation in the inertial and kinematic responses of the piles, especially before liquefaction. Head rocking displacements were within 5% of each other during liquefaction. Post liquefaction, the concrete-filled FRP piles showed lower response compared to the traditional concrete pile. The results suggests that concrete-filled FRP piles, especially those made from carbon fibre, provide practical alternatives for use. Full article

Vegetation restoration is an effective strategy to improve the ecosystem function of the Loess Plateau. Soil microbiomes play a critical role in maintaining soil multifunctionality (SMF). However, the role of aggregate-scale microbial communities and interactions in regulating SMF during vegetation restoration remains poorly understood. Here, we selected six types of vegetation restoration measures in the Loess Plateau, including natural grassland (NL), Medicago sativa (MS), Hippophae rhamnoides (HR), Caragana korshinskii (CK), Armeniaca vulgaris (AV), and Populus alba (PA), and used abandoned land (AL) as a control to identify key microbial mechanisms driving SMF at the aggregate scale. The results show that vegetation restoration increased bacterial diversity, fungal network complexity, and SMF, especially in AV. In contrast, fungal diversity and bacterial network complexity exhibited asynchronous dynamics across different-sized aggregates. Soil microbial diversity peaked at micro-aggregates (0.053–0.25 mm), while fungal network complexity increased with decreasing aggregate size. The structural equation model confirmed that fungal community composition in large macro-aggregates (>2 mm) and fungal network complexity in <2 mm aggregates were the key drivers of SMF. Our results emphasize the divergent mechanisms by which microbial properties influence SMF across aggregate sizes, highlighting the importance of fungal communities in maintaining soil ecosystem functions. Full article

Soil fertility plays a crucial role in crop productivity, particularly in cocoa cultivation, which is highly dependent on soil quality that directly influences both productivity and sustainability. Understanding how to achieve and maintain soil fertility on cocoa farms is fundamental to sustaining higher yields. Cocoa production in Ghana and Togo remains low, at 350–600 kg/ha, compared to the potential yield of over 1–3 tons per hectare. Given the growing demand for cocoa and limited arable land, adequate soil nutrients are essential to optimise productivity. Soil fertility indices (SFIs) have been widely used as soil metrics by integrating multiple physical, chemical, and biological soil properties. In this study, standard analytical methods were employed to evaluate the SFI through laboratory analyses of 49 surface soil samples collected at a depth of 0–30 cm with an auger. Eleven soil chemical indicators were analysed: pH (water), organic matter (OM), potassium (K), calcium (Ca), magnesium (Mg), available phosphorus (P), total nitrogen (N), cation exchange capacity (CEC), electrical conductivity (EC), and carbon-to-nitrogen ratio (C/N). Principal component analysis, followed by normalisation, was used to select a minimum dataset, which was then integrated into an additive SFI. Results indicated that N, Ca, Mg, CEC, and pH were within the optimal range for most surveyed locations (96%, 94%, 92%, 73%, and 63%, respectively), while OM and C/N were within the optimal range in approximately half of the study area. Available P, K, and C/N were highly deficient in 100%, 67%, and 96% of surveyed locations, respectively. Soil fertility varied significantly among locations (p = 0.007) and was generally low, ranging from 0.15 to 0.66. Only 20% of the soils in the study area were classified as adequately fertile for cocoa cultivation. Therefore, it is necessary to restore soil nutrient balance, especially the critically low levels of K and P, through appropriate management practices that improve fertility over time and help close the yield gap. Full article

Soil organic carbon (SOC) is an essential indicator of soil fertility, health, and carbon sequestration capacity. Its proper management improves soil structure, productivity, and resilience to climate change, making rapid and reliable SOC assessment essential for sustainable agriculture. Visible and near-infrared (Vis–NIR) spectroscopy offers a non-destructive and cost-effective alternative to conventional laboratory analyses, allowing for the simultaneous estimation of multiple soil properties from a single spectrum. This study aimed to predict SOC content using machine learning techniques applied to Vis–NIR spectra of 860 soil samples collected in the Sierra Nevada de Santa Marta, Colombia. The spectra (400–2500 nm) were acquired using a NIR spectrophotometer, and the soil organic carbon (SOC) content was quantified using a wet oxidation method that employs dichromate in an acidic medium. A hybrid modeling framework combining Random Forest (RF) with support vector regression (SVR) and XGBoost was implemented. Spectral pretreatments (Savitzky–Golay first derivative, MSC, and SNV) were compared, and spectral bands were selected every 10 nm. The 30 most relevant wavelengths were identified using RF importance analysis. Data were divided into training (80%) and test (20%) subsets using stratified random sampling, and five-fold cross-validation was applied for parameter optimization and overfitting control. The RF–XGBoost (R² = 0.86) and RF–SVR (R² = 0.85) models outperformed the individual RF and SVR models (R² < 0.7). The proposed hybrid approach, optimized through features, and advanced spectral preprocessing demonstrate a robust and scalable framework for rapid prediction of SOC and sustainable soil monitoring. Full article

Three organic soil amendments of different origins (chicken manure, fungal biomass obtained through biological fermentation, and a leonardite-based humic acid product) were applied to young chestnut trees, alongside mineral fertilizer, which when applied alone served as the control. During the second year, bud break pattern, photosynthetic activity, leaf carbohydrate concentrations, soil properties, and leaf nutrient content were evaluated across multiple sampling events. Sampling time significantly influenced most measured parameters. The addition of organic amendments accelerated bud break, influenced plant nutrient uptake, and modified soil properties. Notably, soil organic matter increased following chicken manure and fungal biomass applications, available phosphorus decreased under fungal biomass and leonardite-based humic acids (to 14.5 and 12.4 ppm, respectively, compared to 17.5 ppm in the mineral fertilizer control), and soil iron concentrations tripled under leonardite-based humic acids relative to the control. However, no significant effects were observed on photosynthetic performance or leaf carbohydrate concentrations. Discriminant and hierarchical cluster analyses revealed clear differences among amendments, with the humic acid-based product exerting distinct effects. As there are not many data available in the literature on the efficacy of organic amendments in chestnut cultivation, the present results underscore the importance of the site-specific selection of organic amendments, tailored to soil characteristics (in the present trial, an acidic soil) and specific nutritional objectives to optimize tree physiological performance. Full article

Morel mushrooms (Morchella spp.) are highly prized for their culinary and economic value. Understory cultivation, leveraging the symbiotic relationship between morels and trees, has gained increasing popularity. However, the effects of this practice on belowground microbial communities and nutrient dynamics remain poorly understood. In this study, we examined how understory cultivation of morels (Morchella sextelata) under five different tree species affects soil bacterial and fungal communities, as well as nutrient availability and mineral element content. The results revealed that soil physicochemical properties responded variably to morel cultivation under different tree species. Notably, understory morel cultivation reduced soil NO₃⁻-N by 38–67% across tree species, whereas NH₄⁺-N remained stable, reflecting the distinct nutrient preference of Morchella and associated trees, and suggesting targeted nitrate fertilization could mitigate nitrogen limitations. Understory cultivation significantly increased soil mineral elements, with Zelkova serrata (Z. serrata) showing the highest concentrations, elevating available potassium (AK), calcium (ECa), manganese (AMn) and boron (AB) by approximately 20%, 13%, 30%, and 168%, highlighting its potential for soil quality improvement. Microbial community composition was also significantly altered, with fungal communities exhibiting more pronounced shifts than bacterial communities, likely due to their closer ecological associations with morels. Importantly, Z. serrata markedly promoted microbial-mediated soil carbon and nitrogen accumulation, driven by mineral binding, root secretions and soil pH value. These findings enhance understanding of belowground effects of morel understory cultivation, revealing that select tree species like Z. serrata can improve soil quality and nutrient cycling, while targeted nitrate fertilization supports sustaining morel cultivation systems. Full article