Search Results (1,257)

The study on the valorization of natural resources through cowpea cultivation represents a challenge to mitigate the negative effects of climate change on the environment and on the food security of the population in drought-affected areas globally, and specifically in the sandy soil area of Romania. Thus, the existence in Romania of an area of approximately 439,000 ha with sands and sandy soils, soils with low natural fertility (below 1.2% humus) and with deficient hydrophysical properties, implies finding solutions for their efficient valorization through ecological modeling of the species/varieties structure, depending on the adaptability of the plant in a given area. In this sense, given the economic importance of cowpea, given by the plant’s properties (drought resistance, source of increasing the organic matter content in sands, source of atmospheric nitrogen fixation, good precursor plant, source of protein for humans and animals), the cultivation of this species in a sustainable agricultural system is outlined, as an alternative solution to the cultivation of other leguminous plants. Considered a crop suitable for a climate change scenario, the conservation of genetic biodiversity and the establishment of technological inputs are essential objectives for promoting cowpea in a sustainable agricultural system, given the increasing drought in the world and the increasing need for protein. Full article

Permafrost peatlands in high-altitude regions store substantial amounts of organic carbon, yet the biogeochemical consequences of thermokarst collapse remain poorly understood. Using a space-for-time substitution approach, we selected four habitats representing a thermokarst development sequence in the Altai Mountains peatlands—slightly collapsed peat mounds (P1), severely collapsed peat mounds (P2), thawed herbaceous peat (PB1), and thermokarst ponds (PB2)—and conducted in situ greenhouse gas flux monitoring, soil physicochemical analysis, enzyme activity assays, and structural equation modeling. We found that thermokarst development fundamentally altered the greenhouse gas source–sink balance through three interconnected mechanisms. First, CO₂ fluxes shifted from net emission in P1 (684.1 mg m⁻² h⁻¹) to net uptake in PB2 (−25.6 mg m⁻² h⁻¹), driven primarily by the oxidative loss of mineral-associated organic carbon in the 40–60 cm layer (71.3% loss), whereas lateral dissolved organic carbon export accounted for only 12.3% of total carbon loss. Second, CH₄ fluxes in PB2 (3.8 ± 0.7 mg m⁻² h⁻¹) reached approximately 43% of the theoretical maximum, with this suppression associated with phosphorus limitation (total phosphorus < 0.05 g kg⁻¹) and a marked reduction in alkaline phosphatase activity. Third, N₂O uptake increased along the thaw sequence to −28.6 μg m⁻² h⁻¹ in PB2, with the 40–80 cm layer contributing 42% more than the surface layer. This increase in N₂O uptake occurred when the soil C/N ratio exceeded 300, a threshold that reflects the substantial stoichiometric imbalance between carbon and nitrogen following thermokarst development. These findings demonstrate that the transition from peat mounds to thermokarst ponds alters the net greenhouse gas source–sink balance through changes in MAOC stability, phosphorus availability, and carbon-to-nitrogen stoichiometry. Our results provide empirical constraints for evaluating carbon-climate feedbacks in cold-region peatlands. Full article

This study evaluated the effects of nitrogen source, temperature, and agitation on fermentation performance and volatile compound formation in an agave juice-based beverage fermented with Saccharomyces cerevisiae. Agave juice contained a high concentration of reducing sugars (156.69 g/L), representing 83.16% of the total sugars, predominantly fructose, and a low assimilable nitrogen concentration (0.069 g/L), indicating nitrogen limitation. Fermentation assays were performed at 18 and 28 °C under static or agitated (100 rpm) conditions, with inorganic or organic nitrogen supplementation. At 28 °C, organic nitrogen supplementation under static conditions increased ethanol production to 72.26 g/L. At 18 °C, fermentation kinetics were markedly slower, but nitrogen supplementation increased ethanol production from 34.25 g/L in the control to 59.89 g/L with inorganic nitrogen, indicating that nitrogen supplementation had a greater relative effect under low-temperature fermentation. Volatile profiling revealed that under static fermentation at 18 °C, organic nitrogen supplementation increased the relative abundance of higher alcohols, particularly 2-phenylethanol, whereas ester formation varied according to both nitrogen source and fermentation temperature. Overall, nitrogen source, agitation and temperature strongly affected both fermentation efficiency and volatile formation, supporting the design of controlled processes to improve aromatic complexity and performance in agave-based fermented beverages. Full article

TiO₂–biochar-based photocatalysts are one of the materials exhibiting adsorption-photocatalytic synergy. They have been widely used in the remediation of water systems. Current reviews in this field predominantly focus on the following aspects. These include the preparation methods for composite materials, the pollutant removal performance, the adsorption–photocatalytic synergy, and environmental applications. However, there are still gaps in understanding the intrinsic relationships among photocatalyst morphology, surface functional groups, reactive oxygen species (ROS) generation, pollutant removal, and interfacial charge-transfer mechanisms. This restricts the potential for further enhancement of photocatalytic performance. To fill this gap, this review provides a comprehensive summary of the impact of various parameters on the morphology of TiO₂–biochar-based photocatalysts during in situ synthesis. These factors include titanium sources, carbon sources, preparation methods, solvents, pyrolysis conditions, and doping modifications. Further analysis is conducted to investigate the effects of morphological structure on the distribution characteristics of surface functional groups (e.g., oxygen- and nitrogen- containing groups), the generation of ROS, and the removal behavior of organic pollutants. Furthermore, this review focuses on the effects of three typical morphologies. The three typical morphologies include surface-adhered, pore-embedded, and interlayer-distributed. The role of morphology in charge transport behavior at interfaces is also examined. We systematically elucidate the mechanisms of coupled interactions among material morphology, surface functional groups, ROS, interfacial charge transport, and photocatalytic performance. An analytical framework is established to explore the relationships among morphology control, structural characteristics, and photocatalytic performance. Lastly, the limitations of TiO₂–biochar-based photocatalysts in environmental remediation processes are summarized. It also points the way forward for future development. Overall, this review provides a new theoretical perspective on the rational design and environmental applications of high-performance TiO₂–biochar-based photocatalysts. Full article

Maritime transport emits a range of atmospheric pollutants, including sulfur oxides (SO_x), nitrogen oxides (NO_x), particulate matter (PM), and volatile organic compounds (VOCs), which contribute to air pollution and are associated with adverse environmental and public health impacts. To mitigate these impacts, the International Maritime Organization (IMO), London, UK introduced the global sulfur cap (IMO 2020), which entered into force on 1 January 2020, limiting the sulfur content of marine fuels to 0.50% m/m. This study systematically reviews the environmental and public health impacts of shipping emissions following the implementation of IMO 2020. A systematic literature review was conducted in accordance with PRISMA 2020 guidelines using Scopus, Web of Science, PubMed, and supplementary sources. Following a structured screening process, 67 studies published between 2020 and 2025 were included and analyzed through descriptive, bibliometric, and thematic synthesis approaches. The reviewed studies consistently reported substantial reductions in sulfur dioxide (SO₂) emissions, sulfate aerosols, and shipping-related particulate matter following IMO 2020. These reductions were associated with improved air quality in major maritime and port regions and reduced population exposure to harmful pollutants. However, the reviewed evidence also identified ongoing challenges, including emissions of ultrafine particles and volatile organic compounds, secondary pollutant formation, contamination associated with scrubber washwater discharge, and reduced sulfate aerosols contributing to positive radiative forcing. Overall, the reviewed evidence suggests that sulfur-related air pollution generally declined following the entry into force of IMO 2020, although these observations should be interpreted alongside other concurrent developments that influenced global shipping activities during the study period. This review synthesizes current evidence on the environmental and public health impacts of IMO 2020, identifies emerging knowledge gaps, and provides an evidence base to support future shipping emission policies and research. Full article

Soil analysis is an important source of information in agriculture and environmental monitoring. However, analytical laboratories are subject to an increasing number of regulatory and accreditation requirements regarding the reliability of their test results. Participation in interlaboratory proficiency tests provides an essential tool to demonstrate the analytical performance of laboratories. This paper describes the results obtained from four proficiency tests evaluating 27 laboratories applying 12 standardized methods to measure key soil properties (moisture, pH, P₂O₅, exchangeable cations, organic carbon, and nitrogen) in two different batches of agricultural soil tested in blind replicates under time-different intermediate-precision conditions. This involved laboratories blindly analyzing two soil samples over a period of 17 and 28 months, respectively, with the aim of assessing the long-term consistency of laboratory performance. Various statistical and graphical methods, including Algorithm-A-based robust estimation of the assigned value, z-scores, z*-scores, and Youden plots, were used to assess individual laboratory performance. More than 80% of the participating laboratories showed satisfactory performance in all these tests. The results of this study highlight the robustness of the time-different blind testing in controlling the analytical performance of laboratories in soil analysis. Beyond conventional proficiency testing schemes, the present study provided laboratories with a unique framework to demonstrate their ability to sustain a high level of analytical performance, under intermediate-precision conditions, over an extended period. Full article

Intensified paddy production plays a crucial role in sustaining rice productivity and food security; however, long-term high-frequency puddling, heavy machinery operations under wet soil conditions, simplified cropping systems, and insufficient organic matter inputs have progressively degraded the physical structure of paddy soils. Such structural degradation not only weakens soil water movement, nutrient supply, and aeration but also restricts rice root penetration, alters rhizosphere processes, and disrupts plant–soil feedbacks. Previous studies have largely focused on individual aspects such as soil compaction, amendment-based improvement, water management, or root responses, whereas an integrated understanding of the multi-source drivers, functional consequences, and restoration pathways of soil structural degradation in intensified paddy fields remains limited. Following the overarching theme of soil degradation and regeneration, this review systematically synthesizes the indicator framework, formation mechanisms, degradation typology, ecological consequences, and regulation strategies of paddy soil structural degradation. We further clarify the transition of degraded paddy soils from single physical constraints to the coupled decline of physical, chemical, and biological functions, and compare the agronomic performance, environmental implications, implementation feasibility, and trade-offs of different restoration pathways. Existing evidence indicates that soil structural degradation in paddy fields can impair root-zone pore connectivity, rhizosphere oxygen supply, nutrient acquisition, microbial-mediated carbon and nitrogen cycling, and greenhouse gas regulation, thereby affecting rice growth, yield stability, and the ecological sustainability of paddy systems. Accordingly, the restoration of degraded paddy soils should move beyond short-term loosening or single-factor amendment toward integrated regeneration strategies that maintain soil structural health, reconstruct plough-layer functions, enhance root–soil interactions, and promote the synergistic recovery of pore networks, aggregates, organic carbon, and microbial processes. This review provides a theoretical basis and research reference for the precise restoration of soil structural constraints and the sustainable management of plant–soil systems in intensified paddy fields. Full article

Urban sewer sediments represent an underexplored reservoir of recoverable organic resources, yet conventional disposal practices, landfilling and incineration perpetuate greenhouse gas emissions and irreversible carbon loss. This study establishes a pH-regulated pretreatment strategy (pH 4, 6, 10, and 12) for selective release of organic matter from sewer sediments under simulated hydraulic conditions (solid-to-liquid ratio of 10 g/L, 1154 rpm). Pronounced non-linear release response across the pH revealed a crucial window at pH 10, where COD release attained 1488.68 mg/L (42.6% enhancement over controls) with a 93.70% organic dissolution rate, while total phosphorus release was simultaneously suppressed by 22.4%. The resulting liquid-phase carbon-to-nitrogen and carbon-to-phosphorus ratios of 62.9 and 320.8, respectively, markedly surpassed control values of 46.0 and 174.5, highlighting the potential for high-quality external carbon source recovery. The mechanistic underpinning integrates mineral surface deprotonation, EPS disintegration, and calcium–phosphorus precipitation. Extrapolated to China’s national sewer network, this strategy could potentially mitigate methane emissions by approximately 1.73 × 10⁷ t/yr and save wastewater treatment plants USD 794.83 million/yr in carbon procurement, while inorganic residues retain potential for construction material reuse. This study offers a feasible pathway toward integrated pollution control and high-value waste valorization, aligning with circular economy objectives in urban water systems. Full article

Biochar and poultry litter have been proposed as soil amendments to improve soil health in coarse-textured agricultural soils, yet their field performance under southeastern U.S. conditions remains inconclusive. This two-year field study evaluated five biochar application rates (0–44.8 Mg ha⁻¹) combined with inorganic fertilizer or poultry litter on selected soil health indicators in a sandy loam Ultisol under sweet corn production in the Georgia Coastal Plain. Treatments were arranged in a randomized complete block design with four replications and analyzed using linear mixed-effects models. Biochar application did not significantly affect aggregate stability, pH, cation exchange capacity, soluble salts, organic matter, active carbon, or estimated nitrogen mineralization, with only a marginal three-way interaction observed for microbial respiration. Poultry litter significantly increased microbial respiration relative to inorganic fertilizer, whereas responses for the remaining soil health indicators were broadly similar between fertilizer sources. Year was the dominant source of variation, with extreme rainfall in 2024 reducing aggregate stability, soluble salts, microbial respiration, and nitrogen mineralization while increasing organic matter and active carbon. These findings indicate that short-term soil health responses were driven primarily by environmental conditions rather than management practices. Under the conditions of this study, either fertilizer source can be used successfully, whereas longer-term studies are needed to determine whether biochar aging enhances soil function in sandy loam Ultisols. Full article

The development of sustainable and climate-resilient food systems increasingly relies on robust analytical methodologies capable of integrating environmental, biochemical, and management-related signals. In this study, a multi-isotope framework based on δ²H, δ¹⁸O, δ¹³C, and δ¹⁵N was applied to assess its capacity to discriminate between contrasting raspberry production systems and to provide chemically grounded indicators of agroecosystem functioning. Raspberry fruits (Rubus idaeus L.; cultivars Opal and Delniwa) were collected during the 2024–2025 growing seasons from two distinct systems in Romania: an organic open-field system and a rainfed agroforestry system. Stable isotope ratio analysis revealed system-dependent isotopic patterns, with the strongest differentiation observed for δ¹⁵N. Nitrogen isotope composition (δ¹⁵N) provided the strongest discrimination, with enriched values in organic fruits (2.73–9.77‰) and depleted values in agroforestry fruits (−3.01 to 0.62‰), reflecting differences in nitrogen sources and cycling pathways. Hydrogen and oxygen isotopes (δ²H: −60.46 to −4.62‰; δ¹⁸O: −6.19 to 10.41‰) were consistent with hydroclimatic variability and evaporative fractionation processes associated with soil–plant–atmosphere interactions. Carbon isotopes (δ¹³C: −28.14 to −22.62‰) provided complementary insights into plant water-use conditions. Multivariate statistical analysis supported the separation between production systems, while short-term fertilisation effects were secondary to system-level controls. The results suggest that raspberry fruits preserve an integrated isotopic fingerprint of production environment and management practices. From an analytical chemistry perspective, this work highlights the relevance of multi-isotope approaches as transferable tools for food authentication, traceability, and sustainability assessment, contributing to the broader application of stable isotope techniques across complex biological systems. Full article

Runoff from manure-fertilized farmlands is an important pathway for microbial contamination of receiving waters within a One Health framework. Although organic fertilizers improve soil quality, their influence on pathogen release under mixed fertilization remains insufficiently resolved. This study aims to establish a quantitative framework linking fertilization intensity to pathogen export, which is essential for developing risk-informed nutrient management strategies. Therefore, controlled simulated rainfall experiments (60 mm·h⁻¹) were conducted on soil plots receiving three nitrogen-equivalent fertilizer regimes: T1 (100% inorganic fertilizer), T2 (37.5% organic nitrogen replacement), and T3 (50% organic nitrogen replacement). Metagenomic sequencing and qPCR (targeting 16S rRNA, E. coli, Cryptosporidium, etc.) were used to characterize pathogen-marker sources, initial soil pathogen-marker burdens, and runoff dynamics during a 50 min rainfall event. A total of 29 pathogen-marker taxa were detected among the 41 targeted taxa. Higher proportions of organic fertilizer were associated with greater initial pathogen-marker loads in the soil and greater cumulative export in runoff, with T3 consistently exhibiting the highest levels across indicators. Based on the two-pool model developed in this study, the fitted total release potential (Total M) of Escherichia in T3 reached ~2.6 × 10⁹ copies·m⁻², compared with ~1.3 × 10⁹ in T1 and ~6.8 × 10⁸ in T2. Interestingly, the relative ranking between T1 and T2 varied among specific pathogen markers, suggesting a potential environmental buffering capacity at moderate organic substitution levels. Across all treatments, pathogen-marker concentrations peaked during the early stages of rainfall, indicating a pronounced first-flush effect. Furthermore, bacterial indicators were mobilized more readily than fungal and protozoan targets, the latter of which were more strongly retained by the soil matrix. Overall, the results suggest that optimized organic–inorganic fertilization ratios, combined with improved manure stabilization, are essential for mitigating downstream microbial contamination potential within a One Health framework. Full article

Nitrous oxide (N₂O) is a major greenhouse gas, and terrestrial ecosystems are among the primary sources of its emissions. Biochar is recognized as an effective soil amendment for mitigating N₂O emissions, but its long-term residual effects and microbial mechanisms in subtropical plantations remain unclear. Therefore, this study evaluated the residual effects of Eucalyptus-derived biochar on soil N₂O emissions six years after a single application and explored associations with nitrogen cycle functional genes. A field experiment was conducted in a Eucalyptus plantation in northern Guangxi with biochar applied at six rates (0–6% w/w). Soil N₂O fluxes were measured in the fifth and sixth years (2022–2023); soil chemical parameters, soil enzyme activities, and N₂O-related microbial functional genes (amoA, nirK, nirS and nosZ) abundance were analyzed. Biochar application significantly reduced ammonium nitrogen content but enhanced nitrate nitrogen content. Urease, protease, and sucrase activities increased, while nitrate reductase, nitrite reductase, and hydroxylamine reductase activities decreased. Furthermore, quantitative analysis revealed substantial variations in functional gene abundances. The abundance of ammonia-oxidizing archaea (AOA-amoA) exhibited a unimodal response, whereas ammonia-oxidizing bacteria (AOB-amoA) showed a robust dose-dependent accumulation. Notably, annual N₂O emissions were suppressed by up to 35.2%, driven by a 3.4-fold increase in nosZ gene abundance and a significant reduction in the (nirK + nirS)/nosZ ratio. This mitigation was attributed to enhanced N₂O consumption by nosZ-harboring denitrifiers and reduced heterotrophic ammonia oxidation. Overall, these findings highlight the pivotal role of long-term organic amendments in steering nitrogen transformation pathways, providing a theoretical basis for sustainable soil management in subtropical plantations. Full article

Warming profoundly influences soil respiration in terrestrial ecosystems, thereby altering global carbon cycling. Understanding the trends and drivers of soil respiration changes in forest ecosystems under warming is essential for assessing regional carbon budgets and ecosystem carbon sink/source dynamics. In this study, a one-year warming experiment was conducted using open-top chambers in a Taxodium hybrid (Zhongshanshan) ecosystem in the northern Jiangsu coastal area, China. Treatments included control (CK) and warming (W), focusing on soil respiration components (soil respiration, Rs; heterotrophic respiration, Rh; autotrophic respiration, Ra) and associated soil hydrothermal and nutrient factors. Results showed that both warming and season significantly affected Rs, Rh, and Ra, all exhibiting a unimodal seasonal pattern peaking in summer. Warming increased winter Ra by 117.39% (p < 0.001). Bivariate models (temperature and moisture) explained more variation in respiration (R² = 0.720–0.893) than univariate models. Correlation analysis indicated that under control conditions, Rs components were significantly positively correlated with microbial biomass carbon (MBC), ammonium nitrogen (NH₄⁺-N), and available phosphorus (AP). After warming, these positive correlations with MBC and AP persisted; however, negative correlations emerged with soil organic carbon (SOC) and its stoichiometric ratios (C:N, C:P). Additionally, Ra showed negative correlations with easily oxidizable carbon (EOC), total nitrogen (TN), and N:P. Overall, these findings suggest that climate warming may enhance soil respiration in the Taxodium hybrid (Zhongshanshan) ecosystem by altering soil thermal-hydrological and nutrient factors, although further validation is needed. Full article

Dissolved organic matter (DOM) plays a key role in shaping lake microbiomes and water quality, yet its spatial variability and regional links to microbial activity remain unclear. Using three-dimensional excitation–emission matrix and self-organizing map analysis on 38 samples from a human-impacted lake network in Hubei (affected by tourism, agriculture, and urban areas), this study clarifies DOM heterogeneity and its environmental connections. Microbial metabolic activity represented by total bacterial content (BC) and Escherichia coli (E. coli) activity was rapidly and automatically measured with a ColiMinder device. Random forest (RF) modeling and principal component analysis (PCA) were applied to identify key drivers of microbial activity and to clarify correlations between DOM characteristics and microbial activitiy. Results indicated that although DOM in all three sectors primarily originated from microbial activities during the flat-water period, Tuanhu (TH) exhibited a higher degree of DOM humification and a larger average relative molecular mass, reflecting stronger terrestrial source characteristics. RF analysis identified NH₄⁺ as the main predictor of both BC and E. coli levels, while total organic carbon (TOC) and total nitrogen (TN) were also important predictors. PCA further revealed clear differences in DOM composition across the lakes. DOM in TH was predominantly autochthonous, whereas DOM in Miaohu (MH) and Guozheng (GZ) was mainly of humic origin. This study adopts an integrated method combining rapid microbial detection, EEM and DOM–microbe correlation analysis to analyze human disturbances across segmented connected lakes in Hubei. It provides scientific support for targeted water quality management of human-influenced freshwater. Full article

To explore a new approach to reducing the use of external carbon sources and phosphorus removal chemicals in conventional wastewater treatment, this study developed an anaerobic–oxic–anoxic sequencing batch reactor (AOA-SBR) system (Rf) with iron shavings addition (180 g, 60 g/L), using a blank reactor (R0) as the control. Synthetic wastewater with a C/N ratio of 7.5 was used as the influent. The operating cycle of the AOA-SBR reactor consisted of a 120 min anaerobic phase, a 120 min aerobic phase, and a 60 min anoxic phase, with a hydraulic retention time (HRT) of 12 h. Results showed that the SVI₃₀ of Rf remained at approximately 35 mL/g. The average removal efficiencies of TN and TP in Rf reached 70% and 96%, respectively, which were higher than those of the control. The addition of waste iron shavings improved sludge settleability and nitrogen and phosphorus removal performance of the biochemical system. Fe-C microelectrolysis significantly enriched Candidatus_Competibacter and Candidatus_Nitrocosmicus while inhibiting nitrite-oxidizing bacteria (NOB). This triggered persistent low-level nitrite accumulation within the system, diversified nitrogen-removal pathways, and ultimately improved the total nitrogen-removal efficiency. The extended anaerobic period in the anaerobic–oxic–anoxic (AOA) mode enriched phosphate-accumulating organisms, achieving synergistic chemical and biological phosphorus removal. This study provides a novel strategy for advanced wastewater treatment without external carbon sources or phosphorus additives. Full article