Search Results (7,617)

The concentrations of 18 chemical elements were determined in the upper soil horizons within the landscapes of river basins in the Eastern Caucasus, using the Ulluchay, Sulak, Sunzha, Samur, Shuraozen (Russia), Karachay, and Atachay (Azerbaijan) rivers as case studies. This research aims to provide an ecological and geochemical assessment of soil conditions in the mountain river basins of the Eastern Caucasus. The ecological status of the soils is largely governed by elevated concentrations of such elements as Zn, Ni, Cu, Mo, As, and Cr, which exhibit both accumulation tendencies and potential toxicity. Environmentally unfavorable areas were identified through an integrated scoring assessment that incorporates the values of four ecological and geochemical indices: the modified contamination factor (mCf), the Pollution Load Index (PLI), the Potential Ecological Risk Index (PERI), and the total contamination index (Zc). According to each index, more than half of the study area is classified as uncontaminated. Low PLI values were recorded for 54% of the sampling sites, and low mCf values for 63%. Based on PERI and Zc, 82% of the sampling sites are categorized as uncontaminated. The integral scoring assessment enabled the delineation of more than a dozen environmentally unfavorable areas, with the highest concentrations observed in the Atachay and Karachay basins, spatially extensive in the Sunzha basin. The formation of environmentally unfavorable zones in terms of soil contamination is primarily driven by natural factors, including lithological conditions, climatic features, complex topography, and the directions of waterborne and mechanical migration. Anthropogenic factors contribute to a lesser extent to the development of high-contamination zones and exert only localized influences near major settlements. The results can be applied to mitigate public health risks and to promote sustainable development of mountain river basins. Targeted measures are proposed for the sustainable management of contaminated areas, including restrictions on agricultural activities and the use of drinking water sources. Full article

Growing environmental concerns associated with Portland cement production, along with the continuous accumulation of construction and demolition waste, have intensified the need for sustainable construction materials and effective recycling strategies. This study experimentally investigates the performance of fly ash-based geopolymer concrete (GPC) incorporating recycled concrete aggregate (RCA) as a partial replacement for natural coarse aggregate, compared to conventional ordinary Portland cement concrete (OPC), with a particular focus on integrated durability performance. Ten mixtures were prepared, including five GPC and five OPC mixes with RCA replacement levels of 0–100% by volume. Mechanical properties were evaluated through compressive, splitting tensile, and flexural strength tests, while durability performance was assessed using water permeability, chloride penetration, acid resistance, elevated temperature exposure up to 1000 °C, and accelerated corrosion tests, supported by SEM–EDX analysis. Results show that GPC outperforms OPC across all replacement levels. Optimal performance was achieved at 20–40% RCA, while at 60% RCA a slight reduction in strength was observed; however, the values remained relatively high, particularly for GPC mixtures, indicating stable performance. A significant reduction occurred only at full replacement. GPC also exhibited lower permeability, enhanced corrosion resistance, improved thermal stability, and better resistance to acid attack. This study provides strong evidence that GPC can effectively compensate for the inherent limitations of RCA, offering a durable and eco-efficient alternative for structural and infrastructure applications. Full article

The ecological status of the two nautical mile (2 nm) coastal waters of Bulgaria (BG) and Romania (RO) is evaluated in terms of eutrophication, focusing on various environmental and chemical indicators related to nutrient enrichment and its effects. Applying the Blue2 Modelling Framework (Blue2MF) Black Sea model, we simulate diverse combinations of nitrogen (N) and phosphorus (P) reduction. By integrating atmospheric and marine conditions, hydrology and environmental dynamics, the model provides a comprehensive framework for analysing the impact of external pressures on the marine environment and can be used to set regional sustainability goals. Each scenario is assessed with respect to environmental impact, such as enhanced water quality and potential alterations in phytoplankton communities. Furthermore, we establish integrated nutrient criteria for eutrophication control, concentrating on the management of both N and P inputs while maintaining the current ratio between them. The model results indicate that a 20% reduction in both N and P from European Union (EU) rivers would result in about a 24% decrease in N within the BG and RO 2 nm coastal waters, whilst sustaining the N:P ratio across various spatial scales—from river inputs to coastal and offshore zones. This approach is valuable for assessing the potential impacts of different nutrient reduction strategies, aiding the effective management of marine ecosystems to address eutrophication challenges. Full article

The extensive use of common petroleum-based plastics in food packaging has raised serious environmental concerns, accelerating the search for biodegradable and functional alternatives. In this study, poly(butylene adipate-co-terephthalate)/curcumin (PBAT/Cur) bioactive composite films with colorimetric sensing properties were successfully prepared via solution casting. A systematic characterization was conducted on the structural, morphological, barrier, antioxidant, antibacterial, and colorimetric properties of the films. The optimal PBAT/Cur1% films exhibited potent antioxidant activity (DPPH scavenging up to 95.6%) and moderate antibacterial activity against E. coli and S. aureus. Additionally, curcumin incorporation not only increased the water contact angle of the PBAT/Cur1% films, indicating enhanced surface hydrophobicity, but also concurrently improved the barrier properties, as evidenced by a reduced water vapor permeability (WVP of 14.58 g·mm/m²·day·kPa) and a lower oxygen transmission rate (OTR of 7.533 × 10⁻³ cm³/m²·day·Pa) compared to the neat PBAT films. Notably, the films displayed a distinct and rapid color change from yellow to reddish-brown upon exposure to ammonia vapor, suggesting their promise for on-package visual freshness indication. These findings highlight PBAT/Cur composite films as a sustainable option for active and intelligent food packaging, with combined antioxidant, antibacterial, and colorimetric properties, making them promising for packaging protein-rich foods (e.g., meat and seafood). Full article

The purpose of this research is to investigate the potential of aromatic coconut waste-derived biochars, namely coconut husk biochar (CHB) and coconut empty fruit bunch biochar (CBB), as low-cost, sustainable, and locally available adsorbents. Biochars were characterized using SEM, XRD, XPS, and XRF to evaluate their physical and chemical properties, followed by CO₂ uptake, moisture uptake, and methylene blue (MB) adsorption experiments. The results demonstrated that CBB exhibited the highest CO₂ uptake of 4.44 mmol g⁻¹, outperforming CHB (2.39 mmol g⁻¹) under temperature-programmed desorption. Notably, the water-washed biochar (CBB-w) exhibited a marked decrease in CO₂ uptake, providing strong supporting evidence that naturally occurring mineral species play an important role in the CO₂ adsorption mechanism. The quantity and type of naturally occurring potassium-containing oxides and salts strongly influenced CO₂ and moisture uptake. In contrast, isotherm analyses using the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models indicated that CHB exhibited a superior MB adsorption capacity (30 mg g⁻¹), reflecting the different adsorption mechanisms governing gas- and liquid-phase adsorption. The estimated production cost of aromatic coconut waste-derived biochar ranged from approximately US$0.83–1.11 kg⁻¹, depending on production scale. These results demonstrate that aromatic coconut waste-derived biochar represents a promising low-cost and sustainable adsorbent for environmental applications, particularly CO₂ capture and dye removal. Full article

Water hyacinth leaves (WHL) are an inexpensive renewable fuel resource that can be employed for energy creation through hydrolysis of simple fermentable reducing sugars. In this work, a hybrid microwave irradiation (MWI)–ternary deep eutectic solvent (TNDES) system involving choline chloride (ChCl) as a hydrogen bond acceptor (HBA), triethanolamine (TEOA) as an amine-based hydrogen bond donor (HBD), monoethylene glycol (MEG), diethylene glycol (DEG), or triethylene glycol (TEG) as polyol-based HBD components was employed as an efficient and green material for pretreatment of WHL for further transformation of the polysaccharide portion. The results showed that hybrid MWI/TNDES (ChCl-TEOA-MEG, ChCl-TEOA-DEG, and ChCl-TEOA-TEG) pretreatments were very efficient for lignin removal from WHL, with efficacy ranging from 80.4 ± 3.2 to 87.7 ± 3.8% compared with pretreatment using hybrid MWI/binary NDES (ChCl-TEOA) (75.6 ± 2.4%). The higher efficacy of the hybrid MWI/TNDES pretreatment was attributed to the impacts of MWI on extracting biological materials and the lower viscosity, higher pH, and lower density associated with the TNDESs. The results indicate that WHL pretreated using hybrid MWI and ChCl-TEOA-MEG, ChCl-TEOA-DEG, and ChCl-TEOA-TEG resulted in significantly boosting cellulose digestibility (4–5 times that of pristine WHL and 1.5 times that of hybrid MWI/ChCl-TEOA-treated WHL). The effect of MWI/TNDES pretreatment was confirmed by scanning electron microscope (SEM) pictures, and lignin and hemicellulose elimination were clearly observed in Fourier transform infrared (FTIR) spectra. The lignin-rich material separated by the hybrid MWI/TNDES pretreatment was analyzed using thermogravimetric analysis (TGA) to obtain the thermal behaviors of this hybrid, pretreated WHL material. In our experimentation with hybrid MWI/TNDES, under optimum circumstances of MWI time of 6 min, MWI power of 300 W, and a temperature of 90 °C, 43–49 g/L TRS yield was achieved by acid-catalyzed hydrolysis employing WHL substrate after being optimized by the single-factor experiments (SFE) approach, while the optimized TRS for untreated WHL and hybrid MWI/binary ChCl-TEOA were estimated to be 12 g/L and 32 g/L, respectively. The hybrid MWI/ChCl-TEOA-TEG pretreated WHL resulted in a high ethanol yield (ca. 22.3 g/L) by Saccharomyces cerevisiae after 72 h of fermentation. This work demonstrates the potential of WHL as a sustainable bioenergy feedstock for bioethanol production in industrial biorefineries. The research establishes effective and green solvent pre-treatment materials and methods (based on hybrid MWI/TNDES) for the efficient removal of lignin and hemicellulose from WHL and cellulose recovery. In general, the research contributes to the development of environmentally friendly and cost-effective hybrid MWI/TNDES processes for WHL biomass conversion and offers strong evidence that hybrid MWI/TNDES processes represent a high-potential method for managing WHL infestations while generating useful products. Future studies should further investigate ways to enhance the efficacy of acid-catalyzed hydrolysis processes and assess the scalability of the technology for industrial applications. Full article

The smart city concept promotes the use of innovative solutions to improve residents’ quality of life while supporting sustainable urban development. In the context of climate change and rapid technological advancement, there is a growing demand for energy-efficient cooling systems that use natural resources. This study evaluates the influence of the hydrological regime of the Warta River on its cooling potential in Poznań, one of the largest cities in Poland. Based on hydrological data collected between 1971 and 2024, the distributions of river discharge and water temperature were analysed, as these represent the two key parameters determining the feasibility of river-based free-cooling systems. Considering environmental flow requirements and water temperature thresholds, several operating scenarios were developed to simulate cooling capacities of 100, 150, and 200 MW at temperature differences (ΔT) of 3 and 5 K. Among the analysed variants, the lowest cooling demand scenario (100 MW, ΔT = 3) provided suitable operating conditions for a river-based free-cooling system during 10,582 days, corresponding to 53.6% of the study period. In contrast, the highest cooling demand scenario (200 MW, ΔT = 5) was feasible during 43.9% of the analysed period. The results indicate that the Warta River has considerable potential as a natural cooling source for free-cooling applications, although this potential exhibits pronounced seasonal variability. The highest cooling capacity can be achieved during spring and autumn, while lower capacities are available in summer and the lowest in winter. River water temperature was identified as the dominant limiting factor, accounting for approximately 96% of all cases in which free-cooling operation was not feasible. Furthermore, the observed increase in river water temperature has reduced the number of summer days during which the required cooling capacity can be achieved. The findings enable the identification of periods when river water can fully or partially replace conventional mechanical cooling systems. They also provide a framework for assessing the seasonal and operational potential of surface waters in support of future investments integrating rivers into urban cooling infrastructure. Full article

This study explores the development of low-friction, water-based coatings tailored for industrial applications in pharmaceutical glass packaging. The study focuses on scalable deposition strategies to obtain durable low-friction coatings suitable for industrial implementation. To balance mechanical performance and application efficiency, two different application approaches based on a two-component coating (aminosilane primer and lubricant) were investigated. In the first case, the coating is deposited in two steps, while in the second, a single deposition step is used. Characterization through contact-angle measurements and X-ray photoelectron spectroscopy confirmed successful deposition of the primer on the glass surface. Scratch resistance tests revealed an increase in the critical load for fracture initiation from 4.5 N for uncoated glass to 6.5 N for the best-performing coating, indicating improved resistance to surface damage. Friction performance was assessed via tribological tests, which demonstrated that the primer–lubricant coatings achieved the lowest coefficient of friction (approximately 0.2), compared with uncoated glass (stabilizing at approximately 0.3 after an initial value of 0.5) and lubricant-only coatings (approximately 0.4–0.5), confirming the beneficial role of the primer in the coating system. Representative profilometry measurements indicated sub-micrometric coating thicknesses, while UV–Vis measurements confirmed that the coatings preserved the high optical transparency of the glass substrate, with average visible transmittance values above 90%. Furthermore, the successful implementation of the coating using an automated spray system demonstrates its potential for scalable industrial production. These findings support the potential of environmentally sustainable water-based coatings for pharmaceutical glass packaging by combining improved mechanical performance with preserved optical transparency and compatibility with scalable spray deposition. Full article

Cereal production is increasingly constrained by soil degradation, water scarcity, climate variability, and rising disease and weed pressure. This review synthesizes current knowledge on the role of regenerative agronomic practices in cereal production, with particular emphasis on soil health, plant disease management, water-use efficiency, and yield stability. Available evidence consistently indicates that the greatest benefits arise not from individual practices but from integrated systems combining reduced tillage, crop residue retention, diversified crop rotations including legumes, cover crops, organic fertilization, and biologically based pest management. Such practices can increase soil biological activity and its ability to limit disease by enriching functionally beneficial microbial communities and limiting pathogens through competition for resources and niches, antibiosis, hyperparasitism, and the induction of plant resistance. They can also improve soil structure, water infiltration, water retention, and crop resilience to drought stress and, under certain conditions, reduce erosion, nutrient losses, and yield variability. However, the effects of regenerative practices are strongly dependent on soil type, climate, nitrogen balance, pest pressure, and the extent of adoption of regenerative practices. Risks may arise during the transition period, including yield declines, nitrogen immobilization, weed infestation, and increased disease pressure. Evaluation of these systems should encompass not only yield but also the grain quality and phytosanitary status, soil organic carbon stocks throughout the soil profile, N₂O emissions, and production profitability. The review covers cereal systems from temperate, humid, arid and semi-arid zones, and the results were interpreted considering climate, soil quality, water availability, and agronomic practices, as the same practice can produce different effects in different agroecological zones. Further research should prioritize long-term, multifactorial experiments conducted across diverse agroecological environments that integrate agronomic performance, environmental sustainability, and crop quality. Full article

Alkali-activated mortars (AAMs) have emerged as sustainable alternatives to conventional hydraulic cement (HC) matrices produced with natural sand. In this context, interest in the valorization of industrial by-products to develop eco-efficient construction materials has gained crucial academic and industrial attention. This study investigates the feasibility of producing AAMs incorporating copper slag (CS) as an artificial fine aggregate (AFA) to partially or completely replace natural sand. Moreover, the binder matrix was formulated using 80% CS and 20% HC as precursors, activated with different alkaline solutions (Na₂SiO₃ + NaOH) at activator-to-precursor mass ratios ranging from 0.15 to 0.35. Concurrently, CS was incorporated as AFA at volumetric replacement levels of 0%, 25%, 50%, 75%, and 100%. The AAMs were evaluated in terms of workability, physical performance (i.e., bulk density, water absorption, and void content), and mechanical performance. The results demonstrate that the workability of the AAMs increased with higher AFA dosages, reaching a maximum improvement of 23.8% compared with the AAM without AFA. The bulk density of the AAMs increased monotonically with increasing AFA content (consistent with the higher density of AFA with respect to natural sand), whereas water absorption and void content decreased progressively. Although all AAMs exhibited significantly lower compressive strengths than M1 at 7 and 28 days, the differences progressively decreased with curing age. At 56 and 90 days, M5 and M6, incorporating 75% and 100% AFA, respectively, achieved mean compressive strengths that were not statistically different from those of M1, indicating that the mixtures with the highest AFA contents maintained later-age mechanical performance within the variability of the conventional reference mortar. The study demonstrates the feasibility of the synergistic utilization of CS as both precursor and AFA in AAMs. This dual-pathway valorization closes materials loops and advances circular economy principles within the construction sector. Full article

Tillage practices influence soil structural stability by modifying the soil physicochemical environment and biological processes. However, the relationships among tillage, soil depth, Glomalin-related soil proteins (GRSP), and soil aggregate stability remain insufficiently understood, particularly in the Mollisols of Northeast China. A long-term field experiment was conducted to investigate the effects of three tillage practices, including no tillage (NT), deep tillage (DT), and rotary tillage (RT), across four soil depths (0–10, 10–20, 20–30, and 30–40 cm). Soil physicochemical properties, glomalin-related soil proteins (total glomalin, TTG; easily extractable glomalin, EEG), and soil aggregate stability indices, including mean weight diameter (MWD), geometric mean diameter (GMD), and the percentage of water-stable aggregates (R_0.25), were determined. Pearson correlation analysis and structural equation modeling (SEM) were employed to elucidate the relationships among soil physicochemical properties, GRSP, and aggregate stability. Tillage practices significantly altered soil physicochemical properties, particularly soil moisture and electrical conductivity, with responses varying across soil depths. Deep tillage generally enhanced EEG accumulation and improved aggregate stability compared with rotary tillage, whereas TTG exhibited relatively smaller variations among treatments. Soil moisture was positively correlated with GRSP and aggregate stability, whereas electrical conductivity showed predominantly negative relationships with biological indicators. Correlation analysis showed significant associations among soil physicochemical properties, GRSP, and aggregate stability. In the SEM, soil physicochemical properties were positively associated with both GRSP (standardized path coefficient = 0.205, p < 0.05) and aggregate stability (standardized path coefficient = 0.416, p < 0.05), whereas the direct pathway from GRSP to aggregate stability was not statistically significant. Tillage and soil depth were significantly associated with variation in soil physicochemical properties and GRSP, while soil depth also showed a significant direct association with aggregate stability. These results indicate that the final SEM supported a stronger statistical association of soil physicochemical properties with aggregate stability than of GRSP with aggregate stability. Although GRSP was correlated with aggregate stability in the correlation analysis, its independent contribution to aggregate stability was not supported by the final SEM. These results provide new insights into the processes associated with soil structural stabilization and offer a scientific basis for optimizing tillage management to improve soil quality and promote sustainable agricultural development in the black soil region of Northeast China. Full article

Renewable-powered agricultural water systems are often assessed as solar-pumping devices, but their sustainability depends on a service chain linking crop-water demand, hydraulic duty point, power electronics, storage, water quality, governance, operation and end-of-life management. This structured integrative review synthesizes peer-reviewed and practice-oriented evidence on photovoltaic pumping, hybrid renewable irrigation, grid-interactive pumps, micro-hydro assistance and renewable-powered brackish-water reverse osmosis (PV-RO). Evidence was screened across four source families and coded by service function, energy architecture, hydraulic duty and dominant sustainability pathway; recurring combinations were consolidated using explicit separation and merge rules. It develops an archetype-based screening framework for ex ante appraisal of irrigation, desalination and circularity risks. Seven technology-service archetypes are identified: direct PV pumping, PV-to-tank pumping, PV with electrical buffering, grid-interactive PV pumping, PV–wind hybrid irrigation, micro-hydro-assisted irrigation and PV-RO water making. The framework links each archetype to its operating envelope, evidence maturity, enabling subsystems, sustainability pathways, minimum indicators and ordinal triggers for deeper due diligence. Hydraulic storage is usually the lowest-regret reliability buffer for open-field irrigation, whereas batteries are justified mainly when pressure stability, fertigation timing or night-time operation has high agronomic value. PV-RO is a distinct water-making archetype and is environmentally defensible only where feed-water characterization, energy recovery, pretreatment, product-water agronomy, membrane management and permitted concentrate disposal are embedded in design. Two synthetic applications demonstrate archetype selection and due-diligence escalation. Responsible deployment requires service-oriented screening that integrates hydraulic design, groundwater governance, procurement quality assurance, circularity obligations and social inclusion before field implementation. Full article

Background: Fresh-cut apples are highly susceptible to quality deterioration due to enzymatic browning and oxidative degradation of bioactive compounds. This study investigated the effects of conventional polyethylene packaging (PE, Pack 1) and two innovative biodegradable packaging materials (Pack 2 and Pack 3) on the stability of bioactive compounds in fresh-cut Golden Delicious apples during refrigerated storage. Individual phenolic compounds ((+)-catechin, caffeic acid, (−)-epicatechin, p-coumaric acid, rutin, and quercetin) were quantified by HPLC-PDA, while spectrophotometric assays were used to determine total phenolic content (TPC), total flavonoid content (TFC), and antioxidant capacity (ABTS and DPPH). The environmental performance of the packaging materials was assessed through Life Cycle Assessment (LCA) using SimaPro v.9.5.5. Results: Polyphenol stability was significantly influenced by packaging and storage time (p < 0.001). Compared with fresh-cut apples at t0, Pack 2 promoted a 17.4% increase in total phenolic content after 21 days, whereas Pack 1 and Pack 3 showed reductions of 31.0% and 37.6%, respectively. HPLC analysis revealed compound-specific responses, with rutin and quercetin being markedly better preserved in Pack 3 after 21 days (17.65 and 1.93 mg/100 g, respectively) than in Pack 1 (0.67 and 0.19 mg/100 g, respectively). Two-way ANOVA confirmed significant effects of storage time, packaging, and their interaction on TPC, TFC, ABTS activity, and all individual phenolic compounds (p < 0.001), whereas DPPH activity was not significantly affected (p > 0.05). Pearson correlation (TPC–ABTS, r = 0.6885, p < 0.001) and principal component analysis indicated that antioxidant capacity was more closely associated with the qualitative phenolic profile than with total phenolic concentration alone. LCA highlighted environmental trade-offs among the packaging systems: Pack 1 showed lower impacts in several categories, Pack 2 displayed an intermediate environmental profile, whereas Pack 3 reduced dependence on fossil resources but exhibited higher land- and water-use impacts together with limitations related to end-of-life management. Conclusion: Packaging materials significantly affected the preservation of phenolic compounds and antioxidant activity in fresh-cut apples while exhibiting distinct environmental profiles. The results demonstrate that no packaging system simultaneously maximized product quality and environmental sustainability, highlighting the importance of integrating analytical performance with life-cycle assessment when developing innovative food packaging solutions. Full article

Water hyacinth has become a major environmental problem in aquatic ecosystems worldwide, including Indonesia, due to its rapid growth and extensive surface coverage. Transforming this invasive biomass into high-quality compost offers a sustainable solution for biomass management and agricultural utilization. However, information regarding the combined effects of decomposer selection and the compost aeration process on compost quality, nutrient transformation, and agronomic performance remains limited. This study was conducted in Rawa Pening, Central Java, Indonesia, to determine how decomposer type and turning regime (specifically the frequency and method of mechanically aerating the compost pile) influence the quality of water hyacinth compost and to identify the most suitable formulation for pak choi (Brassica rapa L.) growing media. The experiment consisted of four sequential stages: composting, compost quality assessment, compost selection, and plant growth bioassay. Three decomposers (EM4™, cow dung, and Stardec™) were evaluated under turning and no-turning conditions using a factorial completely randomized design. Compost quality was assessed based on physicochemical characteristics, nutrient composition, compost yield, and correlation analysis. The best compost treatment was subsequently evaluated in different soil–compost mixtures using ANOVA, PCA, and correlation analysis. The results demonstrated that turning and decomposer selection acted synergistically to determine compost performance. Cow dung consistently produced the highest compost yield, whereas Stardec™ combined with turning generated the most mature compost, characterized by the lowest C/N ratio and the highest nitrogen and phosphorus contents. Plant bioassay confirmed that the optimal growing medium consisted of 50% soil and 50% compost, which maximized vegetative growth by balancing nutrient availability with physical support for root development. No toxicity symptoms were observed, indicating that mature water hyacinth compost is safe for agricultural use. These findings provide practical guidance for selecting decomposers based on compost production objectives and promote the sustainable utilization of invasive water hyacinth. Full article

Unreasonable nitrogen (N) management and the shortage of groundwater resources are prominent problems faced by intensive farmland in North China. The main processes to reduce N₂O emissions under drip irrigation still need to be further explored. This study conducted a three-year field experiment (2021–2024) of wheat–maize cropping system in Hebei Province to study the effects of four N levels under drip irrigation (i.e., N0: no N applied; N150: 150 kg N ha⁻¹; N210: 210 kg N ha⁻¹; N270: 270 kg N ha⁻¹) on yield, N₂O emission, soil carbon (C) and N fractions, enzymes, and N functional genes. The results showed that N rate significantly affected N₂O emissions (p < 0.05). The highest value of N₂O emissions (10.64 kg N ha⁻¹) over three years and yield-scale N₂O emissions (0.25 g kg⁻¹) were found under N270, which were 32.1% and 78.6% higher than those of N210. No significant difference in annual yields between N210 and N270 was found, but the annual yield of N150 was decreased by 14.4% as compared to N210. N rate significantly affected soil C-N fractions and enzymes, in which NO₃⁻-N, MBC, DON, amoA-AOB, and UE enzymes, as the major factors of soil properties, N functional genes, and enzymes affecting N₂O emissions, were more favorably regulated along with the increase in fertilizer N rate. Correlation analysis indicated that amoA-AOB was significantly correlated to N fractions (i.e., NH₄⁺-N, NO₃⁻-N, TN, DON and MBN) and UE enzymes. Structural equation modeling further proved that an increase in fertilizer N rate directly increased enzyme activities related to N transformation, which increased N fractions, thus promoting the abundance of amoA-AOB genes involved in nitrification that stimulate N₂O emissions. Therefore, these findings underscore that N210 was an optimal fertigation strategy for minimizing N₂O emissions without compromising yield, offering a practical pathway for sustainable intensification in water-limited regions. Full article