Search Results (1,254)

Environmental changes driven by land use and climate variability profoundly affect basin water balance, yet their separate and combined effects remain poorly understood in data-scarce regions. This study investigates the individual and combined impacts of land use/land cover (LULC) and climate change on seasonal runoff in the Rokel-Seli River Basin (RSRB), Sierra Leone, over two periods (1965–1990 and 1991–2016). Using LULC maps derived from 1988 and 2013 Landsat imagery and the Soil and Water Assessment Tool (SWAT), we simulated hydrological responses under four scenario frameworks. The results reveal a marked expansion of urban, bare, and agricultural land at the expense of forest cover. The SWAT model satisfactorily captured streamflow dynamics during calibration and validation. Land use change alone increased wet-season runoff by 6.55% and decreased dry-season runoff by −13.15%, whereas climate change contributed changes of +24.87% and −31.43%, respectively. A double mass curve analysis and Budyko framework further revealed a regime shift toward higher runoff efficiency (runoff coefficient increased from 0.67 to 0.69), indicating a loss of basin retention capacity. Notably, land use change partially masked the full hydrological deficit induced by climate change, acting as a counter-buffering mechanism. This study provides critical evidence for water resource authorities and local stakeholders to develop adaptive land use and water conservation strategies in data-scarce tropical basins, emphasizing the need to consider both climatic and anthropogenic drivers in seasonal water availability assessments. Full article

Although Sustainable Urban Drainage Systems (SUDS) are widely recognised as essential components of resilient urban water management, the large-scale planning and evaluation of such systems remain challenging. This study assesses the hydrological and economic performance of SUDS in Madrid (Spain) under the SSP1-2.6 and SSP5-8.5 climate scenarios, applying a dual-scale methodology based on the Curve Number (CN) model. At the catchment scale, SUDS show substantial potential for irrigation reuse, with runoff-rich catchments reaching hydrological saturation earlier (plateau at r ≈ 0.4) and runoff-limited catchments stabilising at higher implementation levels (plateau at r ≈ 0.6). At the parcel scale, partial-coverage configurations (50% irrigation coverage) outperform full-coverage solutions (100% irrigation coverage), achieving maximum retention levels of 70% in SSP1-2.6 and 50% in SSP5-8.5 while requiring less surface area (10–15%). From an economic perspective, positive net present values (NPVs), acceptable internal rates of return (IRRs), and feasible payback periods occur only at very low retention levels (r < 0.05), with financial performance declining rapidly as storage capacity increases. Full article

Historical buildings are highly prone to degradation because they are continuously exposed to the external environment, which represents an extremely aggressive factor. Globally, there are so many historical buildings that need urgent restoration. This paper focuses on finding a new consolidant for real oak old wood and presents a new recipe based on multi-walled carbon nanotubes (MWCNTs) decorated with zinc oxide (ZnO) nanoparticles dispersed in PHBHV solution, aimed at improving old wood properties. The research was conducted on Banloc Castle oak wood, which is predominant throughout the castle. The obtained treatment was applied by brushing onto the wood surface, while the retention and uniform application of the consolidation were confirmed by optical microscopy. One major advantage of the treatment is that the natural color of the wood is not affected, with the total color difference being very small. Another advantage gained after consolidation was the enhanced hydrophobic behavior of the old wood confirmed through water absorption, humidity and contact angle tests. In contrast, untreated wood exhibited hydrophilic behavior and high water and moisture absorption capacity, making aged wood extremely vulnerable to environmental degradation over time. Mechanical tests confirmed that the consolidant solution significantly improved the properties of the wooden material, due to the effective impregnation of the treatment into the wood structure. Furthermore, the MWCNT-based consolidant inhibited the growth of the Aspergillus niger strain, providing antifungal protection and preventing the colonization of microorganisms within the wood structure and its subsequent degradation. Through the methods investigated in this work, it was proven that the treatment is suitable for the consolidation of aged and degraded oak wood materials. Full article

The growing interest in functional bakery products has driven research toward the incorporation of non-conventional plant materials rich in dietary fiber. In this study, the effects of partial substitution of wheat flour with ground kudzu root (Pueraria lobata) at levels of 3%, 6%, 9%, and 12% on dough rheology and bread quality were investigated. Farinograph analysis showed that kudzu addition slightly increased water absorption and dough development time, while significantly improving dough stability and the farinograph quality number. At the same time, a higher degree of dough softening indicated partial weakening of the gluten network at higher substitution levels. The incorporation of kudzu root significantly increased bread yield due to enhanced water retention associated with its high dietary fiber content. However, a reduction in specific volume was observed at the highest substitution level (12%), indicating limitations in gas retention capacity. Crumb structure analysis revealed a shift toward a finer and more homogeneous pore distribution with increasing kudzu content, accompanied by a reduction in large pores. These structural changes were reflected in texture profile analysis, where increased hardness and chewiness were observed, particularly at higher substitution levels, while cohesiveness and springiness were only slightly affected. Partial substitution with kudzu root powder also resulted in a significant increase in total phenolic content, flavonoid content, and antioxidant potential of the breads, with the highest values observed in samples containing 12% kudzu root powder. In addition, breads enriched with kudzu root showed reduced digestible starch content compared with the control sample. Despite these modifications, breads enriched with up to 9% kudzu root maintained acceptable technological quality, balancing improved water retention with moderate changes in structure and texture. The results demonstrate that kudzu root can be used as a functional ingredient in wheat bread, contributing to increased dietary fiber content while maintaining satisfactory processing and quality characteristics. Full article

To alleviate the eutrophication in the Wuliangsuhai watershed and evaluate the pollutant reduction performance of ecological drainage ditches in the Hetao Irrigation District, a controlled field simulation experiment was conducted using synthetic agricultural return-flow water formulated from long-term monitoring data. Three leguminous plant treatments, two microbial substrate treatments, and one control were established to compare the migration and transformation of total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) in overlying water, sediment, and plants under different hydraulic retention time intervals (0–6 h, 6–12 h, and 12–18 h). The results showed that plant treatments generally improved conventional water quality indicators, with increased pH and dissolved oxygen (DO) and decreased electrical conductivity, salinity, and total dissolved solids, whereas microbial substrate treatments tended to reduce DO. Pollutant reduction performance differed among treatments. Medicago sativa showed the strongest TN removal from overlying water, Microbial biological rope exhibited the best TP removal from overlying water, and Melilotus suaveolens performed best in COD reduction. Among all plant treatments, Astragalus laxmannii exhibited the most stable overall performance and a relatively strong integrated capacity for nitrogen and phosphorus retention. Most TN and TP reduction in overlying water and sediment occurred during the initial hydraulic retention time interval of 0–6 h, whereas TN plant uptake became more evident during 12–18 h. These findings suggest that ecological drainage ditches vegetated with locally adapted leguminous species have potential to mitigate agricultural non-point source pollution in arid irrigation districts. In particular, Astragalus laxmannii appears to be a promising candidate for ecological ditch design in the Hetao Irrigation District. However, this study was conducted under controlled synthetic return-flow conditions rather than with actual field drainage water, and no tracer-based hydrodynamic verification was performed; therefore, the reported hydraulic retention time effects and treatment efficiencies should be interpreted cautiously. Further field-scale validations under real drainage, seasonal variation, and long-term operation conditions are still needed. Full article

Sand grain size strongly influences the physical and hydraulic behaviour of sandy soils, particularly water retention, pore distribution, and water movement under unsaturated conditions. This study evaluated the effect of five sand grain-size classes, ranging from very coarse to very fine, on pore distribution, aeration, water retention, and unsaturated hydraulic conductivity. Quartz sand samples with different particle sizes were saturated and subjected to matric tensions ranging from 10 to 15,000 hPa. Very fine sand (0.053–0.106 mm) showed the highest field capacity (0.38 m³ m⁻³) and available water content (0.30 m³ m⁻³), which were associated with a predominance of pores between 0.2 and 3 μm in diameter. In contrast, coarser sand fractions were dominated by macropores (>50 μm) and exhibited lower water retention. Permanent wilting point values remained low and similar among grain-size classes (≈0.02 m³ m⁻³). Under unsaturated conditions (matric tensions > 100 hPa), very fine sand exhibited hydraulic conductivity values up to ten times greater than those of coarser fractions. Overall, decreasing sand particle size increased water retention and plant-available water while reducing macroporosity and aeration capacity. These findings demonstrate that sand grain-size distribution plays a major role in regulating water dynamics in sandy soils and may support the development of more efficient irrigation and soil management strategies to improve water conservation and plant water availability in drought-prone environments. Full article

This study develops a ternary Fe-based geopolymer system composed of metakaolin (MK), red mud (RM), and fly ash (FA) for the preparation of sustainable water-retaining subgrade materials for sponge-city roadbed applications. Unlike conventional formulations primarily designed for structural strength or rapid permeability, the proposed MK–FA–RM system was designed to improve water-storage capacity while maintaining adequate mechanical support and environmental compatibility. In this ternary system, MK provides highly reactive aluminosilicate species for geopolymer network formation, RM introduces Fe-bearing phases and enhances industrial solid-waste utilization, and FA contributes to particle packing, workability, and resource efficiency. A constrained ternary mixture design implemented using Design-Expert software was adopted to optimize precursor proportions. Within the investigated compositional range, the fitted first-order mixture model showed acceptable statistical adequacy for preliminary composition screening (R² = 0.86). The optimal blend (60% MK, 30% RM, and 10% FA) achieved a 7-day compressive strength of 8.37 MPa and a water retention rate of 35.3% under ambient curing conditions, satisfying the strength requirement considered for the target subgrade/base-layer application. Microstructural and phase analyses suggest that the synergistic interaction of the three precursors promoted Fe-modified aluminosilicate gel formation together with conventional geopolymer gel products, while improving matrix continuity and preserving interconnected pore space for water storage. This multiscale structural effect helps explain how the material achieved a balance between water retention capacity and mechanical support. Under the tested conditions, the material maintained acceptable residual strength after short-term exposure to water, acid, and sulfate-containing solutions. Life-cycle assessment indicated a 70% reduction in CO₂ emissions compared with ordinary Portland cement, while pilot-scale cost analysis showed a 39% lower production cost than MetaMax-based geopolymer materials. Pilot-scale application further demonstrated the constructability and water-regulation potential of the material in practical environments. Overall, the proposed ternary Fe-based geopolymer demonstrates that Fe-rich industrial wastes can be engineered into low-carbon and economically viable water-retaining subgrade materials that balance hydraulic regulation, structural adequacy, and sustainability. Nevertheless, long-term durability, cyclic loading performance, and direct nanoscale characterization of Fe-bearing gel evolution still require further investigation. Full article

Improving the water-holding capacity (WHC) during the processing of rabbit meat can effectively enhance the texture of the final product, but it remains a practical challenge. This study aims to develop an ultrasound-assisted curdlan curing strategy to reduce the water loss of rabbit meat during the processing. Herein, the water retention performance, myofibrillar protein (MP) structure, and processing adaptability of rabbit meat as affected by the ultrasound-assisted curdlan curing treatment were investigated. Compared with the control group, ultrasound-assisted curdlan treatment increased WHC by 14.0% and reduced cooking loss by 15.4%. Moreover, this combined treatment showed significantly higher WHC and lower cooking loss than curdlan or ultrasound treatment alone (p < 0.05). Moreover, the ultrasound-assisted curdlan curing resulted in higher ultraviolet absorption and fluorescence intensity of myofibrillar proteins (MPs) in rabbit meat, but the intensity of the main protein band observed in SDS-PAGE was lower. Furthermore, the rabbit meat treated with the ultrasound-assisted curdlan curing maintains the highest water content (75.2% for steaming, 74.7% for boiling, 74.4% for microwaving, 70.1% for roasting, and 71.8% for air-frying) under various thermal processing methods. Therefore, the ultrasound-assisted curdlan curing offers a feasible route to improve water retention in rabbit meat, providing an applicable basis for reducing water loss in meat production. Full article

Reliable estimates of volumetric water content at field capacity (θFC) are important inputs for irrigation scheduling because θFC contributes to the estimation of plant-available water, depletion thresholds, and refill targets. In irrigated systems, θFC is therefore an operational decision variable rather than a fixed soil property. However, θFC varies systematically across estimation methods, introducing uncertainty into irrigation management. This study evaluated method-dependent differences in θFC for irrigated tropical soils in the Roldanillo–Unión–Toro agricultural irrigation district (Valle del Cauca, Colombia). Field capacity was estimated at 42 sampling points (0–0.10 m depth) using four methods: Mariotte bottle (MB), filter paper (FP), a pedotransfer function (PTF), and the Richards pressure plate method (RPP). The RPP method was used as an operational reference for comparative purposes, not as an absolute representation of true FC. Agreement and bias were assessed using descriptive statistics, error metrics, regression, Bland–Altman analysis, and texture-stratified comparisons. RPP θFC averaged 39.37% (range: 29.85–46.41%), whereas MB, FP, and PTF produced higher mean values of 42.66%, 44.26%, and 46.38%, respectively. Relative to RPP, mean error and root mean square error increased from MB (3.29% and 5.21%) to FP (4.89% and 8.16%) and PTF (7.01% and 10.82%). Disagreement also varied with soil texture. These results show that low-cost θFC methods are not directly interchangeable with RPP measurements in the evaluated surface layer. Because θFC is commonly used in irrigation calculations, the observed method-dependent differences may affect the estimation of depletion thresholds and refill targets if surface-layer values are extrapolated without local validation. Overall, surface-layer θFC in the Roldanillo–Unión–Toro irrigation district was strongly method-dependent, highlighting the need to account for method-related uncertainty before using alternative θFC estimates as inputs for irrigation decision support. Full article

This study evaluated the use of Michigan bean protein concentrate (PC) and maltodextrin (MD) as alternative wall materials for the microencapsulation of gallic acid, selected as a model phenolic compound due to its well-defined structure and suitability for assessing encapsulation efficiency, stability, and matrix–polyphenol interactions. Increasing the inlet temperature enhanced microencapsulation yield (37.25–55.56%) and total color difference (5.23–13.20), but reduced DPPH• radical inhibition from 90.92% to 54.04%, ABTS•+ radical inhibition from 99.43% to 79.98%, moisture content from 4.98% to 3.51%, and water activity from 0.35 to 0.30. Higher PC concentrations increased efficiency (86.45–99.26%), microencapsulation retention (38.06–100%), moisture content (3.51–4.98%), Aw (0.301–0.358), water absorption capacity (0–2.38 g/g), oil absorption capacity (3.31–3.67 g/g), and emulsifying capacity (0–2.2%). The interaction between temperature and PC content significantly improved yield, antioxidant capacity, and moisture content. Optimal conditions were achieved at a PC:MD ratio of 51:49 and a temperature of 116 °C. Under these conditions, yield, efficiency, microencapsulation retention, total phenolic content, and DPPH• radical inhibition were higher than the values predicted by the model. Morphological analysis revealed that the microcapsules exhibited irregular shapes with dents and particle sizes ranging from 5.43 to 10.19 µm. These findings demonstrate that Michigan bean protein concentrate, when combined with maltodextrin, exhibits strong potential as a wall material for gallic acid microencapsulation, achieving high retention and microencapsulation efficiency. Full article

(1) Background: Nitric oxide (NO) serves as a crucial signaling molecule in plant abiotic stress responses. Although its role in enhancing drought resistance in cotton has been recognized, the specific mechanisms underlying this physiological and molecular regulation remain largely unexplored. This study aims to elucidate the multi-layered mechanisms by which NO modulates drought resistance in cotton; (2) Methods: Cotton seedlings were subjected to drought stress with the application of the NO donor sodium nitroprusside (SNP). A combination of confocal laser scanning microscopy, transcriptional expression analysis, biochemical assay of enzyme activity, virus-induced gene silencing (VIGS), and in vitro protein modification assays was applied to characterize the effects of NO on the drought stress response in cotton; (3) Results: Exogenous NO significantly reinforced drought resistance in cotton seedlings by improving leaf water retention capacity and photosynthetic efficiency, eliminating excessive drought-induced reactive oxygen species (ROS), upregulating the transcription and enzymatic activity of antioxidant enzymes, and promoting stomatal closure. Mechanistically, NO triggered S-nitrosylation of the plasma membrane H⁺-ATPase isoform GhHA2, thereby enhancing its protein stability; (4) Conclusions: These findings reveal that exogenous NO orchestrates cotton drought tolerance via multiple interconnected physiological and molecular pathways, in which the activation of the antioxidant defense system and the modulation of stomatal closure serve as central regulatory mechanisms. Full article

Sustainable southern highbush blueberry production in Florida is increasingly constrained by freshwater competition, variable rainfall, and the chemical vulnerability of coarse-textured and organic-based production media. Reclaimed water irrigation and biochar amendment are promising strategies for improving water use efficiency and root zone function, but their combined implications for blueberry systems remain insufficiently understood. This review synthesizes the current knowledge on blueberry production requirements, the regulatory and operational context of reclaimed water use, and the physical and chemical roles of biochar in sandy and pine bark-based substrates relevant to horticulture in Florida. Particular emphasis is placed on mechanistic links among reclaimed water chemistry, substrate properties, and root zone processes that govern salinity, pH drift, nutrient retention, and solute leaching. The literature indicates that reclaimed water can improve irrigation reliability and provide supplemental nutrients, but may also introduce sodium, chloride, boron, and other constituents, as well as alkalinity, which alter substrate chemistry and increase the risk of salinity stress and nutrient imbalance. Biochar may enhance water retention, cation exchange, and sorption capacity, but its effects are strongly dependent on feedstock, production conditions, aging, application rate, and substrate context. Overall, successfully integrating reclaimed water and biochar into blueberry systems requires substrate-specific and constituent-resolved evaluation under production conditions relevant in Florida. Full article

Hydrogels (HGs), three-dimensional cross-linked hydrophilic polymer networks, have emerged as a promising class of functional materials for sustainable agriculture due to their exceptional water retention capacity, responsiveness to environmental stimuli, and favorable biocompatibility. This review systematically summarizes the key functional properties of hydrogels and critically examines their multidimensional roles within agricultural systems. The major synergistic benefits of hydrogels are highlighted, including (1) improvement of soil physical structure, chemical properties, and the biological microenvironment, thereby facilitating soil remediation; (2) direct enhancement of seed germination, root development, and crop productivity when employed as soil amendments or seed-coating materials; (3) controlled and sustained release of water, nutrients (N, P, K, and trace elements), and pesticides, leading to significant improvements in resource use efficiency; (4) functional delivery of beneficial microorganisms, enabling precise regulation of their activity and efficacy; and (5) advancement of soilless cultivation technologies through the development of sophisticated hydrogel-based substrates. Furthermore, this review discusses the key challenges that currently limit large-scale agricultural implementation, including insufficient biodegradability, potential ecotoxicological risks, and techno-economic constraints. Finally, future research directions are proposed from an interdisciplinary perspective, emphasizing rational material design, performance optimization, and practical field application. This comprehensive review aims to provide systematic theoretical guidance and practical insights for the development and deployment of hydrogel-based technologies in sustainable agriculture. Full article

Electrostatic protein–polysaccharide hydrogels are attractive materials formed without thermal denaturation or chemical crosslinkers and at low biopolymer contents. Their broader application in foods, however, has been limited by slow gelation, with network development often requiring many hours (~18 h). In this study, millimeter-scale hydrogel beads were fabricated from amaranth proteins and xanthan gum by extrusion into glucono-δ-lactone (GDL) solutions (1–5 mg/mL) using hardening times of 10 or 30 min. Beads were successfully formed under all conditions (3.07–3.95 mm diameter), and their physicochemical properties, intermolecular interactions, microstructure, and gel strength were evaluated. Electrostatic attraction remained the dominant force driving gelation. Furthermore, 10 min hardening favored interpolymeric electrostatic interactions, whereas longer exposure reduced them and promoted hydrogen bonding and hydrophobic interactions. These molecular rearrangements were accompanied by a decreased size, lower water retention capacity (WRC), and higher mechanical strength. The mildest treatment (1 mg/mL GDL, 10 min) was post-loaded with a coffee pulp phenolic extract and showed reduced gel strength and electrostatic interactions, suggesting competition for binding sites within the macromolecular network. The extrusion of amaranth protein–xanthan gum mixtures into a GDL bath markedly shortens electrostatic gelation time, supporting this approach as a potential alternative to ionic gelation for the production of millimeter-scale hydrogel beads for food applications. Full article

Population growth and climate change demand technologies for the efficient use of water in agriculture. This study aimed to synthesize and characterize hybrid hydrogels of polyacrylamide and white angico gum (Anadenanthera colubrina), reinforced with kaolinitic clay and soapstone, for potential application as soil conditioners and nutrient carriers. The hydrogels were obtained via radical polymerization, followed by alkaline hydrolysis (0.1 mol L⁻¹ NaOH) to convert amide groups into carboxylates. The results indicated that the HPAD formulation [constituted by white angico gum (1:1); 5% (w/w) kaolin and 5% (w/w) steatite (soapstone)] presented the best balance, with a maximum compressive force greater than 200 N, thermal stability up to 310 °C, and a swelling capacity of 60 g/g in saline medium, surpassing the limits of viability for use in soil. The kinetics followed the pseudo-second-order model, and the point of zero charge (pH 9.0–11.7) favored phosphate retention. It is concluded that the HPAD hydrogel, one of several hydrogel formulations developed in this study, is a viable and safe technical alternative, with non-toxicity exceeding 80% in Artemia salina assays and capable of optimizing water and nutrient efficiency in agricultural systems. Full article