Search Results (18,114)

Quercus variabilis is one of the primary species for plantation regeneration across China’s warm-temperate and subtropical zones. However, its long-term monoculture leads to ecosystem instability. Soil fungi are essential for nutrient cycling and ecosystem functioning, yet their responses to oak-dominated mixed plantations remain insufficiently understood. This study investigated the soil fungal communities among Q. variabilis monoculture (QV), mixed plantations of Q. variabilis and Platycladus orientalis (PO), Q. variabilis and Pinus tabuliformis (PT), and Q. variabilis, P. orientalis and P. tabuliformis (PPQ). The results showed that PO and PPQ plantations contained significantly higher concentrations of SOC, TN, and TP compared to QV monoculture. Ascomycota and Basidiomycota were identified as the dominant fungal phyla across four plantation types, with PO exhibiting the highest relative abundance of Ascomycota (60.85%) and fungal alpha diversity. The soil fungal communities across all plantations were predominantly saprotrophic, followed by mixotrophic modes. The relative abundance of saprotrophic fungi was significantly greater in the mixed plantations, peaking in PO at 44.69%. The soil fungal communities in both PO and PPQ plantations exhibited higher network interaction density. The SOC, TN, TP, water content, zinc, and β-glucosidase activity served as key environmental drivers of fungal community composition. Overall, the mixed plantation of Q. variabilis and P. orientalis most effectively improved soil fertility, enhanced fungal diversity, and increased network complexity, suggesting its potential as a sustainable afforestation strategy for oak-dominated ecosystems in the low hilly regions of western Henan. However, these findings are based on a single sampling period, and long-term monitoring is required to confirm its sustained ecological benefits. Full article

Gravelly soil is widely used in western China but suffers from poor gradation, low water stability, and weak freeze–thaw resistance. Traditional cementitious stabilizers involve high energy and carbon emissions. To address these issues, a novel, eco-friendly gravelly soil stabilizer was prepared from waste foamed concrete (WFC) via crushing, ball milling, and high-temperature calcination. This study systematically evaluated stabilization performance and mechanisms. Results indicate that the WFC stabilizer significantly enhances soil properties. At the optimal 30% dosage, the 28-day unconfined compressive strength (UCS) reached 6.5 MPa (a 333% increase), and water stability was significantly improved. Under freeze–thaw conditions, the 30% dosage yielded a mere 2% mass loss after five cycles, with the UCS reaching 9.56 MPa (a 437% increase). Microstructural analyses (XRD, SEM) revealed that hydration generates calcium silicate hydrate (C-S-H) gel and katoite (Ca₃Al₂(SiO₄)_3−x(OH)_4x). These products effectively fill soil pores and the spaces of the particles, optimizing the microstructure. This study provides a sustainable pathway for WFC recycling and offers a relatively lower energy consumption, low-carbon and high-performance stabilizer for reinforcing gravelly soil subgrades in cold regions. Full article

Against the backdrop of global climate change and the “carbon neutrality” target, the ecological quality improvement of the Loess Plateau—a key region for ecological restoration in China—and its impact on vegetation carbon sources hold significant importance for regional carbon balance and ecological security. Based on MODIS and meteorological reanalysis data from 2002 to 2024, this study constructed the Remote Sensing Ecological Index (RSEI). Combined with a carbon source/sink model, it systematically assessed the spatiotemporal coupling evolution characteristics of ecological environment quality and vegetation carbon storage capacity in the Loess Plateau, and explored the synergistic driving mechanisms of major hydrothermal and surface factors. The results indicate the following: (1) From 2002 to 2024, the ecological environment of the Loess Plateau improved significantly, with the RSEI rising from moderate to good. This improvement was accompanied by a marked decrease in surface dryness, an increase in surface wetness, and notable growth in vegetation cover, revealing a positive coupling relationship characterized by “reduced surface dryness—increased surface wetness—enhanced vegetation restoration.” (2) Regional vegetation carbon storage capacity strengthened markedly. Gross Primary Productivity (GPP), Net Primary Productivity (NPP), and Net Ecosystem Productivity (NEP) all showed significant increasing trends, and the proportion of area classified as carbon sink increased substantially. (3) Spatially, carbon sink distribution exhibited a pattern of “higher in the southeast, lower in the northwest.” Sub-regions A and D were identified as core areas with higher ecological quality and carbon sink capacity, whereas sub-regions B and C were more ecologically fragile and served as primary carbon source areas. (4) The implementation of soil and water conservation measures on the Loess Plateau has effectively enhanced regional carbon storage capacity. Vegetation restoration, improved water conditions, and reduced surface dryness have jointly driven the transition of the Loess Plateau ecosystem from a “vulnerable type” to a “recovering type”, while ecological restoration projects have played a certain role in enhancing the carbon sink. This study provides a theoretical basis and scientific–technological support for ecological protection and high-quality development in the Yellow River Basin. Full article

Solid-waste-based cementitious materials have been widely applied in soil stabilization. However, their durability in practical engineering applications remains inadequate, which may lead to performance degradation and challenges for long-term serviceability. In this study, the durability of solid waste-based cementitious materials (CSD)-solidified soil was improved by adding RL and polypropylene fibers (PP). The research results indicate that the addition of RL hinders the ingress of water into the sample, which is beneficial for improving the water stability and resistance to dry–wet cycles of CSD solidified soil. The addition of PP can suppress crack propagation and effectively enhance the freeze–thaw cycle resistance of solidified soil. When the dosage of RL and PP is both 0.2%, CSD-RP solidified soil exhibits excellent durability performance. After 28 days, the water stability coefficient reached 82.8%, representing a 9.5% increase compared to the control group. After undergoing dry–wet and freeze–thaw cycles, the strength loss of the samples was 36.7% and 47.3%, which was 8.6% and 10.5% lower than that of the control group. Microscopic test results show that cyclic failure promotes the formation of pores and cracks in the sample, while the hydration products generated by the reaction of cementitious materials densify the soil. Compared with the control group, the total porosity of CSD-RP samples decreased by 2.45% and 2.19% after wet–dry and freeze–thaw cycles, further indicating that co doping of RL and PP is beneficial for reducing the degree of structural degradation of the samples. Full article

Environmental pollution from plastics is largely driven by inadequate waste management, particularly in food packaging that relies heavily on petroleum-derived materials. This study utilized gelatin capsule waste (GCW) as a sustainable biopolymer and incorporated yellow peacock flower extract (YPE), obtained via ultrasound-assisted extraction (UAE), at various concentrations (0–2%, w/v) to develop biodegradable films with enhanced functional and antioxidant properties. The main phenolic constituents of YPE were flavonoid aglycones and their glycosylated derivatives. YPE showed total phenolic content of 98.44–129.34 mg GAE/g dry extract, with ABTS, DPPH, and FRAP antioxidant activities ranging from 5.51 to 8.11, 3.17–7.63, and 3.86–5.82 mg TE/g dry extract, respectively. Incorporation of YPE into GCW films significantly improved light barrier properties, thermal stability, mechanical strength, and antioxidant activity, along with a reduction in water vapor permeability and an increase in contact angle, indicating enhanced film hydrophobicity. All films exhibited excellent biodegradability, with complete disintegration within 15 days under soil burial conditions. Films containing 2% YPE (GF4) showed significantly higher thickness, tensile strength, and thermal stability, along with increased opacity, compared with the control (GF0), indicating a reinforcing effect. FTIR analysis revealed the interaction between protein and phenolic compounds from YPE. In a food application model, GF4 film pouches (5 × 5 cm²) effectively delayed oxidative deterioration of dried shrimp during storage at 25 ± 2 °C for 15 days. These findings highlight YPE as a promising bioactive ingredient for biodegradable active packaging and demonstrate the feasibility of GCW as a sustainable biopolymer for eco-friendly films. Full article

Summer cover crops can improve soil fertility and contribute to nitrogen (N) supply in temperate cropping systems, yet the effects of mixture composition and sowing timing remain insufficiently documented. This study evaluated biomass production and N accumulation of five multispecies cover crop mixtures grown in Estonia during 2024–2025 under two sowing dates per year. Aboveground biomass, botanical composition, and carbon (C) and nitrogen concentrations were measured to assess productivity, species contributions, and residue quality. Earlier sowing was generally associated with higher biomass and N accumulation, with first-sown mixtures producing, on average, 38.7% more biomass than later-sown mixtures. Mixture performance was strongly shaped by species composition and competitive hierarchies. Total N accumulation of the cover crop mixtures ranged from 42 to 275 kg N ha⁻¹ depending on mixture composition and sowing time, with mixtures dominated by common vetch (Vicia sativa L.) achieving the highest values. Oat (Avena sativa) dominated and contributed substantially to biomass in mixtures lacking competitive legumes, whereas sunflower (Helianthus annuus) and maize (Zea mays) performed less well under delayed sowing. Low-growing species such as Persian clover (Trifolium resupinatum) produced little biomass when grown with highly competitive species. Legumes exhibited lower C:N ratios than non-legumes, while mixture-level values remained moderate, suggesting residue quality with potential for favourable decomposition and nutrient release in summer cover crop systems under temperate conditions. Full article

Background: Cotton straw returning (CSR) is widely implemented in Xinjiang to achieve in situ residue utilization and ameliorate saline–alkali soils. However, its long-term efficacy in improving soil fertility without inducing secondary salinization remains poorly understood. Methods: This study evaluated the effects of different CSR durations on soil physicochemical properties and cotton yield across four major cotton-growing regions of Xinjiang, China (Shawan, Wusu, Manas, and Shihezi). Cotton fields with different CSR durations were classified into four treatments: CK (0 years), T1 (5 years), T2 (10 years), and T3 (20 years). Soil bulk density (BD), exchangeable sodium percentage (ESP), and key soil fertility indicators were measured to assess comprehensive soil fertility and soil secondary salinization risk. Results: CSR generally enhanced soil physicochemical properties, but responses exhibited spatial heterogeneity. Soil BD decreased in Wusu and Shihezi but showed temporary increases in Manas and Shawan. SFI increased continuously with CSR duration in Shawan and Wusu, whereas it peaked at around 10 years in Shihezi and Manas. Cotton yield was highest under the 20-year treatment in Manas but peaked under the 10-year treatment in the other regions. Notably, prolonged CSR (>10 years) elevated ESP in some areas, suggesting an increased risk of secondary salinization. Conclusions: A CSR duration of roughly 10 years appears optimal for balancing soil amelioration and salinity control in saline–alkali cotton fields of Xinjiang. Full article

Biochar is a carbon-rich material produced from biomass pyrolysis whose properties can be tailored for various applications, including soil improvement, water purification, and catalysis. Its light absorption capacity also makes it promising for solar-driven processes like water evaporation. Photothermal membrane distillation (PMD) combines membrane separation with light-induced heating for efficient water purification. Unlike conventional membrane distillation, PMD utilizes light-absorbing materials to enhance vapor pressure and overcome temperature polarization, a common issue in membrane distillation. This study explored the potential of biochars and activated biochars, as filler materials for photothermal membranes, in line with circular economy principles. The mixed matrix membranes were prepared in a single step, via non-solvent induced phase separation starting from a uniform dispersion of the filler in a polyvinylidene fluoride solution. These materials exhibited great heating performance, reaching surface temperature up to 36 °C under a 125 W/m² light source. Increasing the biochar loading up to 15 wt.% resulted in an 85% increase in distillation flux under light irradiation. Full article

Fine-grained dredged clay is difficult to reuse without treatment due to its high water content and weak soil structure. From a sustainability perspective, this limitation poses challenges for the beneficial reuse of dredged materials and often leads to disposal and increased demand for natural resources. In this study, the 28-day mechanical behavior of stabilized dredged clay, treated with cement or lime and modified with coir fiber, polypropylene (PP) fiber, and styrene–butadiene rubber (SBR) latex, was systematically investigated through experimental measurements, with an emphasis on resource-efficient and sustainable ground improvement. The unconfined compressive strength (UCS) results showed that the UCS of dredged clay stabilized with 4% cement was 374 kPa, and this value increased linearly with increasing cement content, reaching 2487 kPa at 16% cement. In contrast, the UCS of dredged clay stabilized with 16% lime was approximately 30% of that achieved with cement at the same dosage, at only 780 kPa, indicating the need to balance mechanical performance with the environmental impact associated with high cement usage and its carbon footprint. In addition, the inclusion of fibers significantly enhanced the UCS of the stabilized soil samples. The experimental results indicate that the UCS of specimens stabilized with 16% cement could be doubled with the addition of fibers, suggesting the potential to achieve target strength with reduced binder content, thereby contributing to a low-carbon and material-efficient design. Among the fibers tested, coir fiber exhibited better performance than PP fiber in improving UCS, highlighting the effectiveness of natural, renewable, and biodegradable materials in sustainable soil stabilization. Furthermore, fiber length also influenced the UCS of the stabilized soil samples. Additionally, the direct shear test results indicated that both fiber content and length played important roles in determining the internal friction angle of the stabilized soil. It was observed that stabilized soil reinforced with 6 mm fibers exhibited a higher internal friction angle compared to that reinforced with 12 mm fibers. These findings provide insights into optimizing material composition for improved mechanical performance while supporting environmentally sustainable and resource-efficient geotechnical practices. Full article

Under dry sowing and wet emergence conditions in Xinjiang, cotton planting with extra-wide film mulching and sowing faced challenges including low soil moisture content and poor soil plasticity. These conditions resulted in inadequate film edge laying, seed exposure, and unstable sowing depth. This study focused on an extra-wide film mulch planter, conducting operational process analysis and parameter optimization experiments. The research first analyzed the soil layer structure required for a high-quality cotton seedbed, described the structural composition and working principle of the extra-wide film mulch planter, and examined the interaction between key components and soil during operation. The primary factors affecting machine performance were identified, and a soil-deflecting device was added to mitigate rapid soil backflow. A coupled MBD-DEM model was developed to simulate the operation of key components, and simulation experiments were conducted. The optimal parameter combination obtained through optimization was as follows: furrowing disc deflection angle of 11°, primary soil-covering disc deflection angle of 20°, operational speed of 3.5 km/h, longitudinal blade height of 16 mm, and spring stiffness of 14 N/mm. Simulation validation under these parameters yielded the following results: covering soil amount ranged from 3.22 kg/m to 3.67 kg/m, with a mean of 3.43 kg/m; seeding qualification rate ranged from 94.97% to 97.52%, with a mean of 96.3%; film hole length ranged from 43.14 mm to 46.86 mm, with a mean of 45.18 mm; and cotton seed sowing depth ranged from 29.51 mm to 31.82 mm, with a mean of 31.23 mm. These simulation results met the operational requirements for extra-wide film mulching and sowing. Field validation experiments were conducted using the optimal parameter combination. The results showed a mean soil-covering thickness of 35.1 mm, mean soil-covering width of 65.3 mm, mean film hole length of 45.7 mm, and mean cotton seed sowing depth of 29.1 mm, with coefficients of variation of 5.1%, 2.6%, 4.7%, and 5.8%, respectively. The field results were generally consistent with the simulation results, confirming the reliability of the simulation model and demonstrating improved operational performance of the extra-wide film mulch planter, making it more suitable for the dry sowing with wet emergence technique. Twenty days after sowing, the mean emergence rate reached 93.3% with a coefficient of variation of 1.0%, indicating stable emergence, which preliminarily validated the effectiveness of the constructed seedbed in promoting cotton growth. Full article

This study considers the potential of utilizing waste glass powder as a sustainable additive to improve the characteristics of clay subgrade soils. A comprehensive experimental program was designed, wherein a selected clay soil was amended with four distinct contents of glass powder that were finely ground: 0%, 3%, 6%, and 9% by weight. The primary objective was to evaluate the resultant improvements in soil strength and the enhanced interfacial bond between the treated subgrade and an overlying Type B granular subbase layer, which was further reinforced with an SS2 Geogrid. To characterize these effects, a suite of laboratory tests was performed, including the Modified Proctor Test, Atterberg Limits Test, California Bearing Ratio (CBR) test, and a large-scale direct shear test. A specially made large-scale instrument for direct shear was employed for the interface testing. The results demonstrate a clear positive correlation between the proportion of glass powder and the improvement in geotechnical properties. The most significant enhancement was observed at the 9% inclusion rate, which yielded a 6.6% increase in the maximum dry density and a substantial 49% improvement in the CBR value. Concurrently, this optimal mix design resulted in a 14% reduction in optimum moisture content, alongside notable decreases in the swelling and plasticity indices by 33% and 39%, respectively, confirming the efficacy of glass powder in stabilizing the clay subgrade. Full article

Soil organic carbon (SOC) plays a critical role in the global carbon cycle and agroecosystem productivity. However, existing hyperspectral inversion models often exhibit significant predictive biases when applied across large geographic scales, primarily due to the spatial heterogeneity of pedogenic environments and background mineralogy. This study proposes a cross-regional SOC prediction method based on an optimal spectral feature set (SOC-OSFS). Leveraging laboratory hyperspectral and SOC data from 17,730 samples collected across the black soil regions of Northeast China and Europe, a core spectral feature set comprising 31 diagnostic bands was extracted using the competitive adaptive reweighted sampling (CARS) algorithm combined with the successive projections algorithm (SPA). Although this SOC-OSFS accounts for merely 1.55% of the original full-spectrum dimensionality (31 out of 2000 bands), it demonstrated robust analytical capability in local modeling across all study regions, yielding coefficients of determination (R² = 0.6714–0.8854). When transferring the prediction model calibrated in the core source domain (n = 10,000) to the other seven independent typical black soil target domains, the direct cross-regional prediction consistently reduced the root mean square error (RMSE) by over 15% compared to that of the full-spectrum models. By further incorporating 20% of the local background samples for intercept correction, the cross-regional predictive accuracy was substantially improved; the goodness-of-fit for the Northeast China target domains increased sharply (maximum R² = 0.8567), and the European target domains, which feature substantially different pedogenic environments, were successfully corrected from negative to positive linear fits. This study validates the efficacy of extracting physiochemically meaningful spectral bands in mitigating the interference caused by spatial heterogeneity, thereby providing a mechanistically grounded and practically viable framework for large-scale SOC estimation via remote sensing. Full article

The growing demand for food production has increased the pressure on soil and fertilizer use, often leading to nutrient losses, soil degradation, and environmental pollution. Green chemistry offers practical solutions to these challenges by encouraging cleaner, safer, and more efficient ways of producing and using fertilizers. This review summarizes recent advances in multi-nutrient sustainable fertilizers developed through green chemistry principles, including renewable raw materials, low-toxicity synthesis methods, and environmentally friendly delivery systems. Different approaches, such as controlled-release carriers, nano-enabled formulations, chelated nutrients, and bio-based coatings, are discussed with a focus on how they reduce nutrient losses and improve soil and plant health. The review also highlights the benefits and limitations of these technologies, gaps in current research, and the need for long-term field studies to assess their safety and effectiveness. Overall, green chemistry-guided fertilizer development shows strong potential to support sustainable agriculture by improving nutrient efficiency while reducing environmental impacts. Full article

Abiotic stress factors, including drought and salinity, severely limit crop productivity worldwide. Furthermore, the extensive use of herbicides, such as glyphosate, disrupts beneficial soil microbiota, further impairing crop growth. Plant growth-promoting bacteria (PGPB) represent a sustainable and efficient strategy to enhance crop yields, particularly under unfavorable environmental and soil conditions. In this study, we characterized Paenibacillus sp. JSM-10, newly isolated from glyphosate-exposed agricultural soil, for its stress tolerance and plant growth-promoting potential, including its morphology examined using complementary microscopy techniques. The strain tolerated up to 0.5 g/L glyphosate, 15 g/L NaCl, and 100 g/L polyethylene glycol (PEG-6000) without significant growth inhibition (p > 0.05), demonstrating robust resilience to such multiple abiotic stresses. Beyond its tolerance, the strain exhibited several beneficial characteristics, including indole-3-acetic acid (IAA) synthesis, siderophore production, and inorganic phosphate solubilization. Furthermore, both living cells and culture filtrates of JSM-10 exhibited a positive trend toward enhancing buckwheat growth under normal and saline conditions, with effect sizes ranging from Hedges’ g = 0.56−0.92. In addition, JSM-10 exhibited antagonistic activity against a range of pathogenic microorganisms, including Nigrospora oryzae, Bipolaris sorokiniana, Alternaria spp., and Escherichia coli. Altogether, these characteristics highlight the Paenibacillus sp. JSM-10 strain and its culture filtrates as promising candidates for application in organic farming aimed at promoting plant growth and improving stress tolerance via plant–microbe interactions. Full article

Straw and no-tillage management, as important practices in conservation agriculture, have the potential to improve soil structure. However, their effects on the aggregate stability of soil and on active organic carbon pools in paddy fields are unclear. To investigate how different tillage and straw management practices affect soil properties, this study drew on a 15-year long-term experiment conducted in a double-cropped rice region in South China. It systematically compared four treatments: no-tillage (NT), conventional tillage (CT), conventional tillage with incorporated straw (CT-SR), and no-tillage with straw mulch (NT-SMR)—in terms of their effects on the distribution and stability of mechanical and water-stable aggregates, as well as the distribution of particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) across various aggregate size fractions. The results showed that: (1) Relative to the CT, NT, and CT-SR treatments, NT-SMR significantly enhanced soil structure, as evidenced by a higher percentage of large aggregates (>0.25 mm) and improved aggregate stability. (2) NT-SMR consistently increased soil organic carbon pools, raising SOC, POC, and MAOC contents by 2.0–14.2%, 5.7–24.3%, and 1.0–11.9%, respectively, compared to other treatments. (3) In this study, stability of soil aggregates parameters (R_>0.25, MWD and GMD) increased combined with higher levels of bulk SOC and >0.053 mm MAOC, but decreased with higher fractal dimension, indicating a direct causal link between organic carbon accumulation and the betterment of soil structure. Overall, NT-SMR promotes aggregate stability through an optimized particle-size distribution and increased SOC, particularly in the >0.053 mm MAOC fraction. This practice is a sustainable long-term strategy for enhancing SOC sequestration and structural stability in paddy. Full article