Search Results (9,521)

Agricultural microplastics threaten soil health, yet rhizosphere microecological responses to microplastic stress in intercropping systems remain unclear. We conducted a pot experiment using two cropping systems (maize monocropping and maize–soybean intercropping) and four polyethylene microplastic (PE-MP) levels (0%, 0.1%, 0.5%, 1.0%) to investigate rhizosphere physicochemical properties and enzyme activities. Results showed a significant interaction between PE-MPs and cropping systems (p < 0.05). In MM, 0.1% PE-MPs exacerbated soil acidification (pH −4.32%) and ionic fluctuations (electrical conductivity +11.12%). At ≥0.5%, PE-MPs significantly decreased total nitrogen (TN) and total phosphorus, induced abnormal available phosphorus accumulation (up to +98.4%), and dose-dependently inhibited β-glucosidase, urease, and catalase activities. Conversely, the IM system exhibited buffering capacity, maintaining pH, electrical conductivity, and TN stability, mitigating nutrient imbalances, and preserving key enzyme functions. PLS-SEM revealed enzyme-specific associations, suggesting that cropping systems and PE-MPs drive enzyme activities primarily by regulating TN and dissolved organic carbon (DOC). Conclusively, maize–soybean intercropping can buffer microplastic-induced physicochemical degradations, indicating its potential as an agronomic measure to mitigate microplastic pollution, though field-scale validations remain necessary. Full article

Severe soil salinization and low fertility significantly constrain sustainable agricultural development in the Yellow River Delta, one of the three major estuarine deltas in China. Despite their ecological importance, the regional-scale spatial interactions between soil salinity and nutrients, particularly regarding their vertical variability, remain poorly understood. This study analyzed 228 soil samples from 76 sites distributed across a distinct salinity gradient, which was determined by constructing a spatial salinity distribution map after sampling. Samples were collected at three depths (0–15, 15–30, and 30–45 cm) to investigate the spatial distribution of soil organic carbon (SOC), total nitrogen (TN), and the C/N ratio, along with their underlying driving factors. SOC and TN exhibited similar spatial patterns, with higher values distributed along both banks of the Yellow River. Horizontally, SOC and TN in the 0–15 cm layer decreased gradually from west to east, whereas the 15–30 cm and 30–45 cm layers showed an opposite trend, increasing eastward. Vertically, SOC and TN contents declined significantly with soil depth (p < 0.05), although the magnitude of this decline varied regionally: the 0–15 cm layer in the western area contained markedly higher nutrient levels than deeper layers, while vertical variation was less pronounced in the eastern and estuarine regions. Both variables were positively associated with total phosphorus (TP), available potassium (AK), soil moisture content (MC), clay content, and pH, but negatively correlated with electrical conductivity (EC), particularly in the 0–15 cm layer. Our results highlight that soil texture, moisture, and salinity affect the spatial heterogeneity and vertical decline of SOC and TN in the Yellow River Delta. Future research should focus on the long-term temporal distribution of the coupling of multiple elements under changing hydrological and salinity regimes. Full article

Chemical pollution from industrial, agricultural, and urban activities represents a major threat to freshwater ecosystems and aquatic organisms. This study evaluated hepatic biomarker responses in Oreochromis niloticus (Nile tilapia) maintained under chronic environmental exposure to water from the Iguaçu River, one of the most polluted urban rivers in Brazil. Juvenile fish were kept in cages at three sites along the river, and hepatic biomarkers were assessed after 15 and 22 months of environmental exposure. Fish showed severe histopathological liver lesions, activation of antioxidant defenses, and oxidative stress responses accompanied by increased DNA damage. Immunological responses, particularly melanomacrophage proliferation and granuloma formation, were also observed across the monitored exposure scenarios. Alterations in plasma biochemical parameters, including AST, ALT, LDH, albumin, and globulin, were consistent with changes in hepatic function. Overall, the integrated biomarker responses revealed distinct patterns of biological alteration among the monitored exposure scenarios and were consistent with chronic exposure to complex environmental contaminant mixtures. These findings are consistent with alterations in liver integrity in fish maintained under long-term environmental exposure in the Iguaçu River. The study highlights the sensitivity of Nile tilapia as a bioindicator species for aquatic biomonitoring and provides valuable information to support environmental monitoring, risk assessment, and conservation strategies for the Iguaçu River Basin. Full article

Soil acidification threatens agroecosystems, yet the coupled, soil-specific proton-buffering mechanisms in permanent-charge soils (PCSs) and variable-charge soils (VCSs) remain insufficiently quantified. This study systematically investigated surface cation exchange, vacant site H⁺ sorption, and mineral dissolution, using batch and kinetic incubation experiments. Results showed that H⁺ buffering in PCSs was dominated by rapid, stoichiometric surface ion exchange, whereas approximately 42% of the total exchangeable acidity increment in VCSs originated from specific H⁺ sorption on vacant, high-affinity surface sites. VCSs exhibited ~10-fold-higher Langmuir proton sorption affinity and Temkin acid-buffering capacity than PCSs, driven by their more homogeneous, pH-dependent surface properties favoring inner-sphere coordination. Base cation release followed Ca²⁺ ≫ Mg²⁺ ≫ Na⁺ ≈ K⁺ across all soils; VCSs showed a twofold-higher Mg²⁺ pseudo-second-order rate constant and a strong Mg²⁺-Mn²⁺ positive correlation (R² > 0.804, p < 0.0001), exposing them to dual risks of Mn phytotoxicity and Mg deficiency during acidification. The well-fitted parabolic diffusion model for Al³⁺ and Mn²⁺ release further indicated prolonged, diffusion-limited metal toxicity risk in VCSs. A critical soil organic carbon (SOC) threshold of 8.1 g kg⁻¹ was identified, exceeding this value effectively retarded acidification via enhanced cation exchange capacity (CEC) and base retention. These findings provided a mechanistic framework for developing soil-specific strategies to manage and mitigate agricultural soil acidification. Full article

River sediments act not only as important sinks for heavy metal pollution in watersheds, but also as potential secondary sources under changing environmental conditions. Heavy metals can enter river systems through industrial wastewater discharge, agricultural non-point runoff, urban stormwater and sewage inputs, mining and smelting activities, and atmospheric deposition. During adsorption onto suspended particles, sedimentation, and resuspension, metals such as Cd, Pb, Cr, Cu, Zn, Ni, As, and Hg progressively accumulate in sediments. Because heavy metals are persistent, non-degradable, and bioaccumulative, contaminated sediments can record historical watershed pollution while also releasing metals back into overlying water under hydrodynamic disturbance, pH and redox fluctuations, organic matter mineralization, benthic bioturbation, and dredging activities, thereby threatening aquatic ecosystem stability and human health. Using a global methodological framework with particular emphasis on Chinese river basins, this review systematically summarizes key issues in the study of heavy metal pollution in river sediments, including spatial–temporal distribution and operationally defined fractionation, pollution levels and ecological risk assessment, source apportionment, and remediation and management technologies. Current evidence indicates that heavy metal contamination in river sediments exhibits pronounced spatial heterogeneity and watershed-specific characteristics. Its distribution is jointly controlled by geological background, land use patterns, source input intensity, hydrodynamic conditions, sediment particle size composition, and organic matter content. Methodologically, the field has evolved from single total concentration monitoring and exceedance-based evaluation toward integrated assessment systems that combine total concentrations, operationally defined fractionation, bioavailability, ecological risk, health risk, and source contribution. The joint use of BCR sequential extraction, the geoaccumulation index (Igeo), the pollution load index (PLI), the potential ecological risk index (RI), the risk assessment code (RAC), sediment quality guidelines (SQGs), receptor models, isotope tracing, and machine learning has substantially improved pollution identification, risk zoning, and source apportionment. Overall, research on heavy metal pollution in river sediments has shifted from descriptive judgments of whether contamination exists toward mechanistic and management-oriented questions concerning pollution sources, risk evolution, and remediation strategies. However, important gaps remain in compound pollution transformation mechanisms, regional background values and evaluation benchmarks, uncertainty in model parameters, long-term dynamic monitoring, and engineering-scale verification of remediation technologies. Future studies should strengthen multi-media, multi-scale, and long-term monitoring and further integrate fractionation analysis, toxicological effects, source apportionment models, and remediation technologies to provide a scientific basis for watershed ecological security and precision management of contaminated sediments. Full article

Reliable cropland, forestland, and grassland maps support resource assessment and ecological management in arid and semi-arid Central Asia. Existing land-cover products often delineate these classes differently, vary in reliability across classes and locations, and may share the same errors even when they agree. This study formulates multi-product fusion as a pixel- and class-specific reliability decision problem. To address this problem, we propose a reliability-adaptive fusion framework, the Discrepancy-Aware Reliability-Adaptive Fusion Network (DRAFNet), using 2020 maps from three global 30 m land-cover products—FROM-GLC Plus, GLC-FCS30D, and GlobeLand30—and variables representing aridity, temperature, precipitation, elevation, and slope. Unlike fixed-weight fusion methods and segmentation models that use the source products only as input channels, DRAFNet retains the categorical source decisions and adjusts each contribution according to its estimated reliability for the assigned class and location. Weight removed from an unreliable source is transferred to a residual expert, which provides an alternative prediction when the source products are unreliable or share the same error. Voting entropy and geo-environmental variables provide contextual information for this decision. On independent test samples from the five Central Asian countries, DRAFNet achieved an overall accuracy (OA) of 0.8275, a Kappa coefficient of 0.7698, a mean intersection over union (mIoU) of 0.7046, and a macro-averaged F1 score (Macro F1) of 0.8241. These values were 0.95–1.38 percentage points higher than those of U-Net++, the strongest benchmark. Local comparisons indicated more coherent spatial patterns and clearer boundaries in areas of pronounced disagreement. The mean and median absolute log-ratio deviations from area statistics reported by the Food and Agriculture Organization of the United Nations (FAO) were 0.618 and 0.450, respectively, both lower than those of the source products. These results support land-resource assessment and ecological management in Central Asia. Full article

Crop rotation and fertilization are two of the most important agrotechnical measures that influence the chemical properties of the soil and its capacity to support stable agricultural production, especially in areas affected by erosion and climate change. The aim of this study was to evaluate the influence of crop rotation and fertilization on the main soil properties (pH, total nitrogen, available phosphorus and potassium, humus content) in moderately eroded cambic chernozems of the Bârlad Plateau, as well as the effect of experimental factors on wheat yield. The research was carried out in the period 2021–2025 in a stationary experiment located on a slope with a slope of 12–13% at “Mircea Moțoc” Soil Erosion Research and Development Station (M.M.S.E.R.D.S.) Perieni. Two wheat cropping systems were analyzed, namely, monoculture and five-year rotation, in combination with five fertilization variants (N₀P₀, N₃₂P₃₂, N₉₆P₉₆, N₁₂₈P₁₂₈ kg ha⁻¹ and 50 t ha⁻¹ manure). The determinations targeted pH, total nitrogen, mobile phosphorus, mobile potassium, humus content in the 0–20 cm and 20–40 cm soil layers and yield. The results highlight the depletion in available nitrogen, phosphorus, and potassium reserves, alteration of soil reaction in monoculture, and significant improvement in N (from 0.1% to 0.19%), P (from 95.5 to 485.5 mg ha⁻¹) and K (from 188.4 to 227.5 mg ha⁻¹) soil content at the time of final sample collection in the five-year rotation. The application of manure as well as the inclusion of legumes and perennial crops in the rotation contributed to the accumulation of organic matter, to the improvement in soil reaction and to the optimization of nutrient cycling. The highest yields, significant at p ≤ 0.001, were obtained with the application of N₉₆P₉₆ 2858 kg ha⁻¹ in monoculture and 3689 kg ha⁻¹ in the five-year rotation. The study confirms that long rotations associated with organic fertilization represent an effective strategy for the conservation of agricultural soil fertility in areas vulnerable to erosion and drought. Full article

The digital divide in developing economies persists as a multidimensional challenge encompassing infrastructure access, digital skills, usage patterns, and social inequality. This paper presents a structured literature review of 63 peer-reviewed articles (2018–2025) examining how intelligent connectivity, the convergence of fifth-generation (5G) mobile networks, artificial intelligence (AI), and the Internet of Things (IoT), can contribute to bridging this divide. The findings reveal that intelligent connectivity offers transformative potential across agriculture, healthcare, education, and financial services. However, its impact is contingent upon enabling governance, institutional capacity, and digital skills. Three contributions emerge: (1) a conceptual framework specifying directional pathways from enabling conditions to intelligent connectivity deployment and inclusive outcomes; (2) a comparative regional analysis (Sub-Saharan Africa, Southeast Asia, and Latin America) identifying context-specific barriers and opportunities; and (3) a socio-technical model positioning intelligent connectivity as an integrated system rather than a purely technological solution. A key limitation is acknowledged: only 16% of the reviewed corpus addresses developing economies, necessitating triangulation with institutional reports from the International Telecommunication Union (ITU), Organization for Economic Co-operation and Development (OECD), and Global System for Mobile Communications Association (GSMA). The paper concludes with open research challenges and policy recommendations for inclusive digital transformation. Full article

Life cycle inventory (LCI) data constitute Phase 2 of life cycle assessment (LCA) and serve as the basis for calculating environmental impacts. In agricultural LCA studies, LCI data are often reported using different scopes, stages, units, and calculation methods, making it difficult to reproduce results and compare studies. The objective of this study is to compile and standardize Phase 2 LCI data reported in agricultural LCA studies into a structured dataset. The dataset is based on 184 peer-reviewed agricultural LCA studies published between 1999 and 2025. Data were collected through a systematic review using Google Scholar, and studies were included if they applied LCA to crop production systems and reported inventory data such as inputs, outputs, emission factors, or calculation equations. Inventory data were manually extracted from each study, including inputs and outputs, emission factors, equations, and data sources. The dataset is provided as an Excel workbook containing linked sheets for study identifiers, inputs, outputs, emission factors, equations, and data sources. Rather than providing newly harmonized inventory values, the dataset organizes extracted and categorized information reported in the reviewed studies using standardized identifiers and categories. The dataset includes more than 2000 inputs, around 1000 outputs, about 200 emission factors, and over 600 data sources. It is intended for researchers, practitioners, and tool developers to support LCI development, cross-study comparison, and integration into databases, knowledge bases, and decision-support tools. Full article

Late blight in tomato caused by Phytophthora infestans can lead to severe economic losses. Early detection is essential for effective disease management. This study investigates the spectral characteristics of healthy and late blight-infected tomato leaves and plants using non-destructive hyperspectral imaging and proposes a cost-effective machine vision system for early disease detection. Hyperspectral images from seven batches of leaf sets and six batches of whole plant sets were taken hourly over a 96 h period under both controlled and artificially infected conditions. The hyperspectral data cubes were processed with an image analysis model that identified healthy vs. infected regions. Key wavelengths (77 from leaf datasets and 24 from plant datasets) were selected using recursive feature elimination and analysed with four machine learning classifiers: k-nearest neighbour, support vector machine, random forest, and artificial neural network. The models differentiated healthy and infected tissue with high accuracy (98–99%). The hyperspectral data were simplified into a multichannel image with most informative wavelengths, using a custom spectral index and binary decision rule. Experimental limitations were addressed, and a conceptual design of practical hardware was proposed: a monochrome camera combined with a multichannel light source and polariser mounted on mobile equipment. Although further trials will be needed, this proof-of-concept study and conceptual hardware design can be adapted in other crops facing similar disease challenges. Full article

Blockchain is one important building blocks of the Internet of the future, called Web3. The Blockchain technology supports a wide range of applications, spanning from Smart Cities and automotive industries, from agriculture to energy. The healthcare sector, in particular, has experienced a profound impact from blockchain-based technologies, paving the way for the development of true digital healthcare systems. By enabling secure and immutable data storage, and facilitating the sharing of this information among all nodes possessing a local copy of the distributed ledger, blockchain plays a vital role in the analysis of healthcare data. This paper provides a comprehensive survey of the main blockchain platforms utilized in the digital healthcare, integrated with a comparative analysis. In addition, the implementation of Innovative permissioned Blockchain for eHealth (IBEH) is presented and discussed in detail. IBEH addresses key challenges in digital health data management, including secure and controlled access to sensitive health information, ensuring data integrity and traceability, and secure sharing between different healthcare institutions and organizations. This is made possible by decoupling the application and blockchain layers and by a flexible, customizable, and easily deployable infrastructure. IBEH integrates the application-oriented and embedded layer with that of a blockchain network built with the MultiChain platform, which uses smart contracts with permissions, REST APIs, and RPC calls. The main features and its associated smart contracts within the healthcare domain are discussed. Finally, the analysis of performance is provided. Full article

Foot-and-mouth disease (FMD) causes significant losses for livestock farmers in affected countries and regions, including Southeast Asia, where several countries are progressing through different stages of the Progressive Control Pathway (PCP) under diverse resource settings. The PCP, developed by the World Organization for Animal Health and the Food and Agriculture Organization of the United Nations, is an outcome-oriented strategy designed to support progress toward the elimination of FMD. In this review paper, we propose an evidence-based framework linking epidemiological tools to each PCP stage requirements based on studies conducted in eight Southeast Asian countries through peer-reviewed research and gray literature. The findings indicate that Stage 1 progression is supported through risk-factor analyses, seroprevalence studies, and participatory epidemiology, while Stage 2 relies on spatial analyses and evaluations of control strategies. Progression to Stage 3 requires evidence of active surveillance systems for rapid detection of new viral incursions, whereas later stages depend on risk assessment, sustained surveillance, and restricting transboundary animal movement. Regional challenges include underreporting, surveillance-system deficiencies, and inconsistent vaccination monitoring. The framework proposed herein provides a practical approach for aligning the generation of evidence with PCP requirements. Ultimately, strengthened regional collaboration that coordinates transboundary risk management is crucial for progress toward sustainable FMD control in Southeast Asia. Full article

The transition from conventional silica nanoparticle (SiNP) production based on purified alkoxysilanes and high-temperature flame hydrolysis of silicon tetrachloride to renewable and waste-derived silicon resources requires more than precursor substitution. It requires a mechanistic understanding of how feedstock mineralogy, silicon speciation, impurity chemistry, and processing history propagate through dissolution, nucleation, condensation, gelation, aging, drying, and pore evolution to determine material performance, environmental burden, and manufacturing feasibility. Although previous reviews have established the technical feasibility of producing silica from secondary resources, their predominant organization by feedstock, synthesis route, or application provides limited ability to explain why nominally similar processes generate materials with markedly different structural and functional properties. This review addresses these through a resource-pull, feedstock-to-function framework that links resource chemistry and process design to critical material attributes, application-specific specifications, sustainability, and scale-up requirements. Agricultural residues, industrial by-products, geothermal resources, waste glass, and fluorosilicate streams are critically compared according to silicon form and phase, reactivity, impurity profile, compositional variability, purification demand, and attainable product quality. Particular attention is given to waste-derived alkaline silicate systems, in which molecular, oligomeric, and colloidal silica coexist and therefore require characterization beyond bulk SiO₂ concentration. Established and emerging processing strategies, including controlled combustion and alkaline extraction, alkali fusion, ambient-pressure drying, microwave and mechanochemical activation, biogenic and biomimetic templating, and continuous processing, are evaluated according to their mechanistic effects, technological maturity, structural control, and demands for energy, reagents, water, solvents, effluent treatment, and capital. Across these routes, gelation and aging emerge as critical transfer stages through which feedstock composition is translated into network connectivity, pore architecture, shrinkage behavior, and ultimately functional performance. Evidence from secondary-source aerogels further shows that properly controlled waste-derived systems can attain BET surface areas of approximately 350–500 m² g⁻¹, within the textural range of many alkoxide-derived materials, indicating that feedstock variability, impurity management, and process control are more important constraints than an inherently lower performance ceiling. On this basis, this review proposes a minimum evidence framework comprising feedstock traceability, intermediate-speciation and colloidal characterization, silicon mass balance, gelation and aging metrics, application-specific qualification criteria, performance-normalized life cycle and techno-economic assessment, process analytical control, and staged pilot validation. Collectively, these principles provide a mechanistically grounded basis for moving sustainable silica synthesis beyond isolated proof-of-concept demonstrations toward reproducible, scalable, application-matched, and commercially credible manufacturing platforms. Full article

Global commodity chains reshape rural territories through interconnected environmental and socioeconomic processes; these dynamics are often examined through the lens of land-use change. Export-oriented agricultural frontiers illustrate how global market integration can generate landscape and societal transformations. In western Mexico, the expansion of the avocado industry exemplifies commodity-driven territorial change, linking land-use dynamics with transformations in rural economies and livelihoods. This study analyzes how export integration into the international avocado commodity chain was associated with transformations in land systems and socioeconomic dynamics across four municipalities in Michoacán, Mexico, between 2003 and 2023. Using high-resolution land-use maps alongside demographic and socioeconomic indicators, we apply a qualitative, comparative and inductive synthesis of spatial and census data to examine how commodity integration interacted with local conditions to shape landscape and territorial organization. Avocado expansion coincided with territorial transformation, including the conversion of pine-oak forest and traditional agricultural lands, as well as changes in labor arrangements, demographic dynamics, and rural livelihood systems. Land-use analysis shows continued orchard expansion and accelerated land conversion after 2015. Socioeconomic indicators reveal population growth, increased female employment, and persistent income inequality, highlighting the uneven incorporation of rural territories into global commodity chains. We identified four territorial pathways: agricultural specialization, agro-industrial urbanization, transitional diversification, and rural commodity integration. These findings contribute to debates on uneven geographical development and commodity frontier expansion by showing how global commodity integration intersects with ecological, economic, and social processes to generate distinct pathways. Full article

Microplastics (MPs) pollution caused by agricultural film residues, organic fertilizer application, sewage irrigation, and atmospheric deposition has gradually become an unignorable interference factor to the sustainable development of the rhizosphere soil and crop in farmland. However, their specific impacts on the rhizosphere and crops remain unclear. Therefore, this review focuses on the current knowledge on the response mechanisms of rhizosphere soil and crops to MP contamination. The density of MPs is generally lower than that of soil mineral particles. Their substantial accumulation in soil can significantly reduce both the bulk density (by increasing total porosity) and the particle density (by diluting the heavy solid phase with light plastic components). The introduction of MPs disrupts the normal metabolism of soil bacterial communities; a disruption directly reflected in functional genes associated with carbon cycling. MPs can interfere with the activity of key metabolic enzymes involved in fungal nutrient cycling, thereby disrupting normal energy allocation and material metabolism. Viruses can regulate the turnover and metabolism of microbial communities through lytic and lysogenic cycles, consequently influencing the carbon fate of MPs. The toxicity and underlying mechanisms of MPs on soil fauna primarily manifest in aspects such as feeding behavior, growth and development, oxidative stress, intestinal toxicity, and reproductive toxicity. The direct effects of MPs on plants include physical barriers and mechanical damage, induction of oxidative stress, interference with nutrient uptake, disruption of photosynthesis and carbon metabolism, and disruption of plant hormone networks. This review identifies critical knowledge gaps, particularly regarding crop quality, field-based soil faunal studies, virus-microbe interactions, and degradation products, and proposes future research directions to better understand the risks MPs pose to agricultural sustainability and food safety. Full article