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Compared with compacted block, the bentonite granules (BG) were increasingly considered as feasible sealing materials for deep geological disposal, due to its superior operationality and installation efficiency. However, further studies are needed to assess the hydraulic response and microstructural evolution of BG. This work focused on the water retention behavior of BG specimens prepared with different grading curves and void ratios (0.6, 0.8 and 1.0), under confined/unconfined conditions following wetting and drying paths. The specimens' pore structure and its evolution were studied using mercury intrusion porosimetry. Results indicated that the water retention capacity was generally unique at high suctions (> about 10 MPa) due to adsorption mechanism, while it was related to pore structure at low suctions. Under confined condition, wetting caused macropore (i.e., inter-aggregate/pellet pores) compression and pore structure rearrangement, while the inter-particle pores kept almost unchanged. BG specimen with more and coarser granules initially exhibited more and bigger macropores, and its initial granular structure was progressively lost upon wetting. Meanwhile, the volume expansion was relatively limited upon wetting at high suctions, below which it gradually became obvious. Comparatively, wetting caused macropore enlargement and even cracks generation under unconfined condition. After saturation under confined condition, drying caused initially macropore contraction and the granular structure was somewhat recovered that could result in further opening of cracks. Besides, the shrinking rate gradually became slow at suction > about 30 MPa. This study is conducive to comprehension and design of engineered barrier system for deep geological disposal. [ABSTRACT FROM AUTHOR]

Soilless substrate stratification is increasing in popularity in the greenhouse and nursery industry globally. The concept of stratifying substrates entails stacking two substrates with different physiochemical properties to augment vertical moisture balances and redistribution for quicker establishment, greater root growth, and quicker time to market. Stratified substrate research to date has estimated or assumed that the static physical properties of a stratified system as the mean of the individual strata components. No research to date has verified or rejected this assumption using a stratified column. The research herein measured the static physical properties of 1) peatlite (85% peat: 15% perlite), 2) unprocessed <12.7 mm aged bark, 3) fine bark particles (#6.3 mm), and 4) coarse bark particles ($6.3 mm). Moreover, these physical properties were measured via 1) using the standard promoter analysis (7.6 cm core), 2) extending the core height by stacking two standard porometer cores (15.2 cm height) of the same strata component atop each other (to identify how water storage and air-filled porosity changes), and 3) stratifying either peatlite over unprocessed bark or fine bark over coarse bark. The results showed that extending the height of the porometer increased drainage and decreased water storage across conventional and stratified systems alike, illustrating the benefit of using cores equivalent to container height when making cultural decisions to manage water efficiently. When stratifying substrates, the system as a whole stores less water and has more airfilled porosity than nonstratified composite profiles (100% peatlite; 100% unprocessed bark) due to gravitational forces draining the higher portion of the container. Assumptions regarding the static physical properties of a stratified system can be made with the standard or extended porometer core for coarse-textured bark substrates used generally in the nursery industry with reasonable accuracy (<5% difference), meaning that nursery growers interested in stratifying their substrates can assess their stratified static physical properties using standard measurements. However, assumptions cannot accurately be assessed for finer peat-based stratified profiles used in greenhouse production and may require further refinement for estimations. The broader implications of this research highlight the storage capacities of a stratified substrate system, which may influence growers' decisions in application and irrigation management. [ABSTRACT FROM AUTHOR]

Magnetic superabsorbents have been successfully synthesized through aqueous solution polymerization, employing sodium alginate as the backbone material, acrylic acid and acrylamide as the polymeric monomers, Fe3O4 nano-particles as the magnetic component, N,N'-methylenebisacrylamide as the crosslinking agent, and ammonium persulfate serving as the initiator. The micro-morphology and thermal stability of these superabsorbents were thoroughly characterized using scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA), respectively. A comprehensive investigation was undertaken to examine the swelling capacity, water retention properties, magnetic responsiveness, and reusability of the magnetic superabsorbents. The findings reveal that these superabsorbents possess an impressive maximum water absorption capacity of 302.7 g/g in distilled water. Notably, their swelling ratios maintain high levels within a pH range of 5–10. Featuring a porous structure, the magnetic superabsorbents demonstrate rapid swelling kinetics, attaining swelling equilibrium within 30 min in a 1 wt% NaCl solution. Furthermore, the superabsorbents exhibit excellent magnetic responsiveness, characterized by a maximum saturation magnetization of 7.91 emu/g, allowing for swift separation under an external magnetic field. Lastly, the magnetic superabsorbents display outstanding reusability, with their water absorption capacity in distilled water still exceeding 90% of the initial swelling ratio after seven reuse cycles. [ABSTRACT FROM AUTHOR]

Water scarcity poses a significant challenge to agricultural production, prompting the development of sustainable technologies to optimize water resource utilization. This study focuses on the synthesis and application of a multifunctional poly (vinylpyrrolidone); PVP-based superabsorbent hydrogel (SAH) for controlled release of essential fertilizers (nitrogen, phosphorus, and potassium) and enhanced water retention in soil. The hydrogel was prepared via a facile one-step approach and compared to a control soil without hydrogel amendment. The reaction was initiated in the presence of poly(vinylpyrrolidone) (PVP) to produce a PVP-based copolymer hydrogel. The hydrogel was then subjected to a basic treatment using either sodium hydroxide (hydrogel #1) or potassium hydroxide (hydrogel #2). The PVP-based SAH exhibited excellent swelling capacity, water retention, and fertilizer release properties. When applied to Pisum sativum plants under drought stress, the hydrogel significantly improved soil moisture levels, nutrient availability, and plant growth parameters compared to the control. The hydrogel #2-amended plants demonstrated enhanced biomass, chlorophyll content, and photosynthetic efficiency, highlighting the hydrogel's effectiveness in mitigating the adverse effects of drought stress. These findings demonstrate the potential of the PVP-based SAH as a promising strategy for sustainable agriculture, offering using readily available and inexpensive raw materials, suggesting a relatively low-cost and scalable production process. Furthermore, the hydrogel facilitates water conservation, controlled nutrient delivery, and improved plant performance under drought stress conditions. [ABSTRACT FROM AUTHOR]

Magnetic superabsorbents have been successfully synthesized through aqueous solution polymerization, employing sodium alginate as the backbone material, acrylic acid and acrylamide as the polymeric monomers, Fe3O4 nano-particles as the magnetic component, N,N'-methylenebisacrylamide as the crosslinking agent, and ammonium persulfate serving as the initiator. The micro-morphology and thermal stability of these superabsorbents were thoroughly characterized using scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA), respectively. A comprehensive investigation was undertaken to examine the swelling capacity, water retention properties, magnetic responsiveness, and reusability of the magnetic superabsorbents. The findings reveal that these superabsorbents possess an impressive maximum water absorption capacity of 302.7 g/g in distilled water. Notably, their swelling ratios maintain high levels within a pH range of 5–10. Featuring a porous structure, the magnetic superabsorbents demonstrate rapid swelling kinetics, attaining swelling equilibrium within 30 min in a 1 wt% NaCl solution. Furthermore, the superabsorbents exhibit excellent magnetic responsiveness, characterized by a maximum saturation magnetization of 7.91 emu/g, allowing for swift separation under an external magnetic field. Lastly, the magnetic superabsorbents display outstanding reusability, with their water absorption capacity in distilled water still exceeding 90% of the initial swelling ratio after seven reuse cycles. [ABSTRACT FROM AUTHOR]

The purpose of this study was to explore the water retention mechanism of chicken claws by detecting the structural changes in collagen in boneless chicken claws under different expansion rates. Firstly, boneless chicken claw collagen with different expansion rates (0%, 10%, 20%, 30%, 40%, 50%) was extracted by the acid–enzyme complex method, and the changes in collagen were determined by scanning electron microscopy (SEM), ultraviolet spectroscopy (UV), Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD), low-field nuclear magnetic resonance LF-NMR) and surface hydrophobicity to explore the mechanism that leads to changes in the water retention performance. The results of scanning electron microscopy showed that with the increase in the expansion rate, collagen molecules showed curling, shrinking, breaking and crosslinking, forming a loose and irregular pore-like denatured collagen structure. UV analysis showed that the maximum absorption wavelength of chicken claw collagen was blue shifted under different expansion rates, and the maximum absorption peak intensity increased first and then decreased with the increase in expansion rate. The FTIR results showed that collagen had obvious characteristic absorption peaks in the amide A, B, I, II and III regions under different expansion rates, and that the intensity and position of the characteristic absorption peaks changed with the expansion rate. The results of the CD analysis showed that collagen at different expansion rates had obvious positive absorption peaks at 222 nm, and that the position of negative absorption peaks was red shifted with the increase in expansion rate. This shows that the expansion treatment makes the collagen of chicken claw partially denatured, and that the triple helix structure becomes relaxed or unwound, which provides more space for the combination of water molecules, thus enhancing the water absorption capacity of boneless chicken claw. The results of the surface hydrophobicity test showed that the surface hydrophobicity of boneless chicken claw collagen increased with the increase in expansion rate and reached the maximum at a 30% expansion rate, and then decreased with the further increase in the expansion rate. The results of LF-NMR showed that the water content of boneless chicken claws increased significantly after the expansion treatment, and that the water retention performance of chicken claws was further enhanced with the increase in the expansion rate. In this study, boneless chicken claws were used as raw materials, and the expansion process of boneless chicken claws was optimized by acid combined with a water-retaining agent, which improved the expansion rate of boneless chicken claws and the quality of boneless chicken claws. The effects of the swelling degree on the collagen structure, water absorption and water retention properties of boneless chicken claws were revealed by structural characterization. These findings explain the changes in the water retention of boneless chicken claws after expansion. By optimizing the expansion treatment process, the water retention performance and market added value of chicken feet products can be significantly improved, which is of great economic significance. [ABSTRACT FROM AUTHOR]

Grouting Fire Prevention technology is the most commonly used technology in coal mines. In order to improve the water holding capacity of the slurry and prevent the cracking and re-leakage of air caused by the loss of water, this paper used sodium alginate, sodium polyacrylate and gasification slag to prepare thick paste mixture, and then used calcium chloride to induce the gelation of the mixed paste surface to form an elastic solid film. A kind of environmental protection slurry of coated gasification slag (hereinafter referred to as coated slurry) with good environmental protection, high strength and elastic solid film with flame retardant and water retention on the outer surface was developed. In the 30°C-300°C range, when the coated slurry was heated, it would have a significant heat absorption and cooling effect. The results show that the hydrophilic -COO-, -OH in sodium alginate forms a synergistic effect with -COO-, -COOH in sodium polyacrylate, and enhances the water absorption of sodium polyacrylate; The interaction of calcium ions with sodium alginate on the surface of the mixed slurry causes gelation and forms a calcium alginate film on the surface of the coated slurry, which prevents water evaporation. [ABSTRACT FROM AUTHOR]

This study aims to synthesize and characterize a sulfated‐starch‐based superabsorbent polymer (S‐SAP). The S‐SAP is prepared by grafting 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid (AMPS) and acrylic acid (AA) onto sulfated starch, which is subsequently crosslinked using N,N‐methylene‐bis‐acrylamide (MBA) via free radical polymerization with ammonium persulfate as the initiator. The successful grafting of AA and AMPS onto the starch backbone improves the thermal stability and increases the swelling capacity of the polymer. The swelling capacity and reusability of the S‐SAP are compared with those of commercial superabsorbent polymers (C‐SAPs). The swelling capacity of the S‐SAP is higher than those of C‐SAPs, reaching 417 g g−1 in distilled water and 47 g g−1 in a 0.15 M NaCl solution. The water absorption kinetics of the S‐SAP shows a good fit with the pseudo‐second‐order model. The polymer prepared herein has potential applications in horticulture and agriculture. [ABSTRACT FROM AUTHOR]

Landfill cover systems should exhibit low gas permeability to minimize the overflow of greenhouse gases and subsequent air pollution. Microbially induced carbonate precipitation (MICP), a biocementation technique, has been applied for subsurface soil stabilization by improving the shear strength of the soil. However, the impact of MICP on the gas permeability of unsaturated soils remains unknown. Considering the role of biocementation in the modification of soil interpores, this study investigated the feasibility of using the MICP technique to reduce the gas permeability of granite residual soils in response to unsaturated conditions. The biocemented soil samples were prepared by mixing soils with MICP chemical solutions at different chemical concentrations. Water retention tests and measurements of gas permeability were performed, in which suction, volumetric water content and gas permeability were continuously monitored. Additionally, energy-dispersive X-ray spectroscopy and X-ray diffraction analyses were performed to investigate the formation of CaCO3 precipitates; scanning electron microscopy was used to study the impact of MICP on the soil interpore structure, and the acid washing method was used to determine the CaCO3 content. The results showed that soils treated with higher concentrations of MICP chemical solutions had higher air entry pressures and residual water contents. This indicates the improvement of water retention due to the presence of MICP, which increases the microstructural porosity and enhances the capillarity, as observed via microscopy. Furthermore, the results revealed that biocementation significantly reduced the gas permeability of the soil and that the change in the maximum gas permeability strongly correlated with the MICP chemical solution concentration and the CaCO3 content. This study highlights the role of MICP in soil–water–air interface studies and the potential application of this biocementation technique to minimizing gas emission issues in landfill cover systems. [ABSTRACT FROM AUTHOR]

This paper presents a study of the hydraulic response of an infinite unsaturated slope exposed to a perturbation of the ordinary seasonal climatic cycle. The ground flow is modelled via a simplified one-dimensional finite difference scheme by decomposing the two-dimensional slope seepage into antisymmetric and symmetric parts. The numerical scheme incorporates two distinct hysteretic and non-hysteretic soil water retention laws, whose parameters have been selected after a preliminary sensitivity analysis. Results indicate that, in the hysteretic case, the "memory" of the perturbation takes a long time to fade, and the ordinary soil saturation cycle is only restored after several years of normal weather. Instead, in the non-hysteretic case, the recovery of the ordinary saturation regime is almost immediate after the perturbation. In contrast with the markedly different predictions of degree of saturation, both hysteretic and non-hysteretic slope models predict virtually identical evolutions of negative pore water pressures, with an almost immediate restoration of the ordinary cycle after the perturbation. [ABSTRACT FROM AUTHOR]

In this work, a bio-based resin of acrylated epoxidized soybean oil (AESO) mixed with three types of active diluents (Isoborneol methacrylates [IBOMA], tripropylene glycol diacrylate [TPGDA], and Ethoxylated trimethylolpropane triacrylate [ETPTA]) is used to form a protective UV-curable coating film on calcium alginate water-carrying microspheres (CA-WCMs). Calcium alginate microspheres (CAMs) have previously been used to encapsulate only ester soluble or oil-in-water core materials, thus limiting their application. After UV-curing with an increased active diluent dose, the pencil hardness, pendulum hardness, and mechanical strength of the CAMs increased. A photopolymerization kinetics study reveals that the maximum double bond (C=C) conversion rates of AESO-IBOMA, AESO-TPGDA, and AESO-ETPTA are 95, 92, and 86%, respectively, and the maximum conversion rate of C=C bond is 87% in their mixed system. Additionally, the water retention rate of the water-carrying microspheres (WCMs) increased with an increasing number of coating layers, plateauing after the number of layers exceeded four. The water retention is favorable, with more than 75% of the water stored for a duration of 50 days. Overall, the cost-effective and environmentally friendly method has shown encouraging results in the acquisition of water-absorbing CAMs, with the potential to overcome existing implementation constraints. [ABSTRACT FROM AUTHOR]

Charcoal, a byproduct resulting from incomplete combustion of biomass in fire events, can modify the physical properties of soil due to its high porosity and large surface area. To evaluate the impact of fire-deposited charcoal on soil hydraulic characteristics, soil–charcoal mixtures were analyzed to investigate the effects of different application doses (wt%: 0, 1%, 3%, 5%, 10% and 20%) of charcoal on soil bulk density (BD), porosity (total, capillary, and non-capillary), residual moisture after free drainage (RM), saturated water content (SC), and saturated hydraulic conductivity (Ks) of loamy and sandy soils collected from subtropical forests in south China. The results showed that the impact of charcoal on soil's physical and hydraulic properties depends on the soil type and the application dose. The incorporation of charcoal significantly decreased the BD of sandy soil (p < 0.001), while a significant decrease in BD in loamy soil was only observed as a result of the higher application doses (10% and 20%) (p < 0.001). Charcoal application doses of 5% or higher led to a significant increase in the total porosity (TP) of sandy soil (p < 0.001) and doses of 3% and 20% resulted in a significant increase in the TP of loamy soil (p < 0.001). The capillary porosity (CP) of both sand and loamy soils significantly increased when charcoal was applied at doses of 3% or higher (p < 0.001). The minimum charcoal application dose that significantly increased the RM in sandy soil was 5%, while for loamy soil, the minimum effective dose was 10%. Charcoal applied at a dose of 3% significantly increased the Ks of sandy soil (p < 0.001), while no significant effect on Ks was observed for loamy soil (p > 0.05). Collectively, our findings suggest that fire-derived charcoal enhances the soil water-retention capacity in subtropical forests, with the effects becoming more pronounced at higher application doses and being particularly notable in sandy soil compared to loamy soil. [ABSTRACT FROM AUTHOR]

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We prepared guggul gum-based hydrogel (GgG-cl-poly(AA)) through a free radical graft copolymerization mechanism in this work. The preparation was carried out using ammonium persulfate as an initiator, acrylic acid as the monomer, and N, N′-methylenebisacrylamide as the crosslinker. The synthesized hydrogel's swelling capacity and equilibrium swelling ratio were thoroughly investigated by optimizing various reaction parameters: reaction time, solvent volume, microwave power, crosslinker amount, initiator concentration, and monomer concentration. The swelling results demonstrated that the synthesized hydrogel can attain a maximum percentage swelling of 980% within 3 h in an aqueous solution. The prepared hydrogel sample was characterized using Fourier transform infrared, X-ray diffraction, scanning electron microscopy, nuclear magnetic resonance, and thermogravimetric analysis. The prepared hydrogel was studied for water retention behavior in the soil, water absorbance in the open air at room temperature, reswelling studies, and resistive swelling studies in various salt solutions at different temperatures and pH values. Notably, the crosslinked hydrogel exhibited a reduced swelling capacity across various salt solutions compared to the aqueous solutions. The biodegradation studies were examined in both soil burial and vermicomposting methods for two months, revealing a maximum biodegradation of 95.65% through the vermicomposting method and 87.7% through the soil burial method. The results indicate that the crosslinked hydrogel based on guggul gum is a potential candidate for various agricultural applications. [ABSTRACT FROM AUTHOR]

BACKGROUND: A model system described in International Organization for Standardization 9360 is the standard method for estimating the humidifying performance of heat and moisture exchangers (HMEs). However, there are no reliable bedside methods for evaluating the ongoing humidification performance of HMEs. Therefore, this study aimed to develop 2 clinically applicable methods for estimating the ongoing humidifying performance of HMEs and to evaluate their reliability in a model system. METHODS: Physiologically expired gas was simulated using a heated humidifier, and ventilation was delivered using a ventilator with constant flow through 3 different types of HMEs. Relative humidity (RH) was measured using a capacitive-type moisture sensor. Water content lost during expiration was calculated by integrating absolute humidity (AH), instantaneous gas flow measured at the expiratory outlet of the ventilator, and time. We also calculated the water content released and captured by the HMEs during tidal ventilation by integrating the difference in AH across the HMEs, instantaneous gas flow, and time. RESULTS: We found that the RH, temperature, and AH were almost constant on the expiratory outlet of the ventilator but rapidly varied near the HMEs. The water content lost by the 3 HMEs was associated with the manufacturer-reported values and inversely correlated with the calculated values of the water content exchanged by the HMEs. The water content released and captured by HMEs was closely correlated with the difference in HME weight measured at the end of inspiration and expiration; however, the water content captured by HMEs seemed to be overestimated. CONCLUSIONS: Our results demonstrated that our system was able to detect the differences in the performance of 3 models of HMEs and suggest that our method for calculating water loss is reliable for estimating the water retention performance of HMEs during mechanical ventilation, even in the presence of a constant flow. [ABSTRACT FROM AUTHOR]

Soil aggregates are clumps of soil particles bound to each other through organic matter. Soil with aggregates has favorable features for crop cultivation, such as adequate water retention and filtration. This feature was clarified from the perspective of the network formed by pores. The connectivity of pore networks in soil was investigated in this study using virtually generated porous media with and without aggregates. The connectivity for drainability was evaluated using the percolation probability (PP), which is represented as a curve of the ratio of the largest subnetwork formed by pores that are larger than a certain value as the value decreases from the maximum to the minimum pore size. Compared with the PP of porous media without aggregates, PP with aggregates has a smaller percolation threshold, which is the point at which PP rises sharply, indicating that soil with aggregates has high drainability. Furthermore, PP without aggregates asymptotically approached the diagonal, whereas PP with aggregates left the diagonal halfway and approached again. This demonstrates that the aggregates contain loosely isolated subnetworks and that the water retained in the aggregates is difficult to drain once the aggregates are filled with water. These findings enhanced our understanding of the water retention property of soils with aggregates. [ABSTRACT FROM AUTHOR]

The aim of the work was to compare the water retention and moisture sorption of viscose (CV) and cotton (Co) fibers carboxymethylated from aqueous media, in presence of NaOH, with sodium monochloroacetate. It was shown previously that under the same treatment conditions, the degree of carboxymethylation was higher in CV and so was the depth within fiber structures to which the carboxymethylation reactions occurred. It was also shown previously, that in terms of their capacity for sorption of a cationic dye (methylene blue), the Co performed better than CV. In this work, the same fibers were tested for their water retention and moisture sorption propensities. The two were sensitive both to the degree of carboxymethylation and the inherent properties of fibers (accessibility, degree of swelling, hornification). But the moisture sorption levels were less sensitive to the degree of carboxymethylation and more to inherent fiber properties whereas the reverse was observed for water retention. In contrast to the prior observations with dye sorption, CV performed better than Co in both moisture sorption and water retention. The poor performance of CV in dye sorption was attributed to the greater depth of carboxymethylation within the fibers that hindered dye permeation, but the same feature was observed to result in better performance (water retention) or not to hinder performance (moisture sorption). These observations highlight the contrasting effects that may arise, of a given set of treatment parameters (fiber type, alkali level in treatment), on efficacy of the product performance. [ABSTRACT FROM AUTHOR]

The water retention capacity of porous materials is crucial in various geotechnical and environmental engineering applications such as slope stability analysis, landfill management, and mining operations. Filtered tailings stacks are considered an alternative to traditional tailings dams. Nevertheless, the mechanical behaviour and stability of the material under different water content conditions are of concern because these stacks can reach considerable heights. The water behaviour in these structures is poorly understood, particularly the effects of the water content on the stability and potential for liquefaction of the stacks. This study aims to investigate the water retention and flow characteristics of compacted iron ore tailings in high columns to better understand their hydromechanical behaviour. The research used 5 m high columns filled with iron ore tailings from the Quadrilátero Ferrífero region in Minas Gerais, Brazil. The columns were prepared in layers, compacted, and instrumented with moisture content sensors and suction sensors to monitor the water movement during various stages of saturation, drainage, infiltration, and evaporation. The sensors provided consistent data and revealed that the tailings exhibited high drainage capacity. The moisture content and suction profiles were effectively established over time and revealed the dynamic water retention behaviour. The comparison of the data with the theoretical soil water retention curve (SWRC) demonstrated a good correlation which indicates that there was no hysteresis in the material response. The study concludes that the column setup effectively captures the water retention and flow characteristics of compacted tailings and provides valuable insights for the hydromechanical analysis of filtered tailings stacks. These findings can significantly help improve numerical models, calibrate material parameters, and contribute to the safer and more efficient management of tailings storage facilities. [ABSTRACT FROM AUTHOR]

In recent years, the development of various hydrogel types has aimed to address concerns regarding the inefficient utilization of water and nutrients in agricultural settings. However, conflicting outcomes have emerged regarding the effectiveness of hydrogel application in agriculture and its potential negative environmental consequences. Therefore, this comprehensive review seeks to evaluate the functionality of hydrogels as water and nutrient reservoirs, while identifying potential solutions to mitigate their environmental impacts based on previous research. By synthesizing data from prior studies, this review analyzes how the performance of hydrogels may be influenced by soil pH, ionic strength, and other solution chemistry factors in the environment. Notably, this review encompasses a comprehensive assessment of the impact of the environmental matrix on hydrogel performance, which fills an important knowledge gap and provides valuable insights for future research directions and practical applications in agricultural lands. Considering sustainability concerns associated with conventional hydrogel applications, it is recommended to explore biodegradable hydrogels derived from natural materials like cellulose. These biodegradable options offer minimal negative impacts on the environment. Although studies on the economic analysis of hydrogel usage are limited, they play a significant role in identifying current obstacles and promoting the adoption of biodegradable hydrogels. Conventional hydrogels have shown greater commercial benefits, but the increasing focus on environmental concerns has driven the development of nature-based hydrogels (e.g., starch) in recent years. However, the trade-off between the relatively high cost of biodegradable hydrogels and their low environmental impacts necessitates more pilot-scale experiments and political efforts in this field. In summary, this review demonstrates that incorporating sustainable hydrogels into soils can effectively improve water and nutrient retention, ultimately enhancing crop production. These findings suggest a promising and sustainable future for hydrogel applications in agriculture, while emphasizing the need for further research, pilot studies, and concerted efforts to strike a balance between economic viability and environmental considerations. [ABSTRACT FROM AUTHOR]

Abstract Water scarcity poses a significant challenge to agricultural production, prompting the development of sustainable technologies to optimize water resource utilization. This study focuses on the synthesis and application of a multifunctional poly (vinylpyrrolidone); PVP-based superabsorbent hydrogel (SAH) for controlled release of essential fertilizers (nitrogen, phosphorus, and potassium) and enhanced water retention in soil. The hydrogel was prepared via a facile one-step approach and compared to a control soil without hydrogel amendment. The reaction was initiated in the presence of poly(vinylpyrrolidone) (PVP) to produce a PVP-based copolymer hydrogel. The hydrogel was then subjected to a basic treatment using either sodium hydroxide (hydrogel #1) or potassium hydroxide (hydrogel #2). The PVP-based SAH exhibited excellent swelling capacity, water retention, and fertilizer release properties. When applied to Pisum sativum plants under drought stress, the hydrogel significantly improved soil moisture levels, nutrient availability, and plant growth parameters compared to the control. The hydrogel #2-amended plants demonstrated enhanced biomass, chlorophyll content, and photosynthetic efficiency, highlighting the hydrogel’s effectiveness in mitigating the adverse effects of drought stress. These findings demonstrate the potential of the PVP-based SAH as a promising strategy for sustainable agriculture, offering using readily available and inexpensive raw materials, suggesting a relatively low-cost and scalable production process. Furthermore, the hydrogel facilitates water conservation, controlled nutrient delivery, and improved plant performance under drought stress conditions.

To investigate the effects of a low-pressure electrostatic field combined with low temperature and high humidity on beef tenderness, this study utilized bovine longissimus dorsi muscle as the experimental material. The analysis included low-pressure electrostatic field thawing (at a temperature of 4 ℃ and relative humidity of 50%), low temperature and high humidity thawing (at a temperature of 4 ℃ and relative humidity of 98%), low-pressure electrostatic field combined with low temperature and high humidity thawing (temperature 4 ℃ and relative humidity 98%), and low temperature thawing (temperature 4 ℃ and relative humidity 50%). The parameters examined encompassed shear force, texture, water distribution, water content, water holding capacity, and sensory evaluation of frozen beef. The findings revealed that low-voltage electrostatic field combined with low-temperature and high-humidity thawing exhibited the shortest thawing time (804 min) compared to the other three thawing methods. The thawing loss (2.06%), cooking loss (26.09%), and centrifugation loss (15.00%) were significantly lower than the other three thawing methods (P

Poly(N‐isopropyl acrylamide) (PNIPAm) is a temperature‐sensitive material with a fast temperature response and a low critical solubilization temperature (LCST) of approximately 32°C, but it swells only 20–40 times after absorbing water. To enhance its water‐absorption properties, we introduced hydrophilic monomers into the NIPAm monomer to prepare a ternary copolymerized superabsorbent polymer. In addition, we characterized this copolymer using various techniques and analyzed its temperature‐sensitive and water‐absorbing properties. The results showed that the optimal synthesis conditions consisted of m(NIPAm):m(AMPS) = 4, 1.5% initiator, 0.3% cross‐linking agent, and 1.0% quaternized ammonium chitosan, which ensured the significant temperature sensitivity of the water‐absorbent resin. Under these conditions, the swelling ratio of the water‐absorbing resin reached 235.3 times, the LCST value was 44.6°C, the water retention rate was 84.9% at 25°C after 12 h, and the shrinkage ratio reached 81.7% at 60°C after 3 h, and 97.6% after 12 h. The resulting material could be rapidly dehydrated at high temperatures and presented clear temperature‐sensitive characteristics while maintaining excellent water‐absorbing properties. [ABSTRACT FROM AUTHOR]

Abstract Rabbit meat is tender, high in protein, low in fat and cholesterol, and offers several nutritional benefits. However, it has a stronger taste and can be challenging to cook. The global rabbit industry has been developing steadily, and China's total rabbit meat production has exceeded half of the world's total production in 2021. Along with the progress of the production process, the meat of the nutrition and taste at the same time, to improve smell also can get better control, solved the problems met in rabbit meat production. This article discusses the attributes of rabbit meat and outlines the deodorization, texture adjustment, and water retention techniques currently used in rabbit meat processing, aiming to offer a theoretical foundation for the advancement of rabbit meat processing technology.

Compacted clay liners are extensively used as barriers to control the upward diffusion of vapors of volatile or semi-volatile organic contaminants released from unsaturated contaminated soils at industry-contaminated sites. This study aimed to investigate the gas diffusion barrier performance of compacted clayey soils amended with three agents including attapulgite and diatomite individually, and attapulgite/diatomite mixture. The properties including water retention, volumetric shrinkage, gas diffusion, and unconfined compressive strength were evaluated through a series of laboratory tests of amended compacted clayey soils. The results demonstrate that the decrease in volume proportions of inter-aggregate pores leads to an increase in unconfined compressive strength (qu). Both hydrophilic groups and microstructures of attapulgite and diatomite result in an increase in water retention percent (Wt) of compacted clayey soil specimens after amendment regardless of the type of agent or initial water content (w0). Furthermore, the ratio of the gas diffusion coefficient (De) to the gas diffusion coefficient in the air (Da) was significantly reduced owing to a decrease in volume proportions of inter-aggregate pores, hydrophilic group, and microstructures of attapulgite and diatomite. Scanning electron microscope analyses revealed that rod-shaped attapulgite filled the inter-aggregate pores formed by clay particles, whereas the disc-shaped diatomite particles, characterized by micropores, failed to obstruct the inter-aggregate pores due to their larger particle size. Mercury intrusion porosimetry (MIP) analyses showed a reduction in pore volume in the inter-aggregate pores, leading to a reduction in the total pore volume for both the attapulgite and attapulgite/diatomite mixture amended clays, which is in accordance with the scanning electron microscope (SEM) results. The findings are pertinent to the practical application of compacted clay liners as gas barriers against the upward migration of volatile or semi-volatile organic contaminants at contaminated sites.

Abstract In agriculture, hydrogels can be addressed for effective operation of water and controlled-release fertilizers. Hydrogels have a significant ability for retaining water and improving nutrient availability in soil, enhancing plant growth while reducing water and fertilizer usage. This work aimed to prepare a hydrogel composite based on microalgae and biopolymers including chitosan and starch for use as a soil conditioner. The hydrogel composite was characterized by FTIR, XRD, and SEM. All hydrogel properties were studied including swelling degree, biodegradability, water-holding capacity, water retention, and re-swelling capacity in soil and water. The urea fertilizer loading and releasing behavior of the prepared hydrogels were investigated. The results revealed that the range of the maximal urea loading was between 99 and 440%, and the kinetics of loading was fitted with Freundlich model. The urea release % exhibited 78–95%, after 30 days, and the kinetics of release was fitted with zero-order, Higuchi, and Korsmeyer–Peppas models. Furthermore, the prepared hydrogels obtained a significant water-holding capacity, after blending soil (50 g) with small amount of hydrogels (1 g), the capacity increased in the range of 99.4–101.5%. In sum, the prepared hydrogels have the potential to be applied as a soil conditioner.

The hydrologic performance and cost-effectiveness of green stormwater infrastructure (GSI) in climates with highly variable precipitation is an important subject in urban stormwater management. We measured the hydrologic effects of two bioretention basins in San Antonio, Texas, a growing city in a region prone to flash flooding. Pre-construction, inflow, and outflow hydrographs of the basins were compared to test whether the basins reduced peak flow magnitude and altered the metrics of flashiness, including rate of flow rise and fall. We determined the construction and annual maintenance cost of one basin and whether precipitation magnitude and antecedent moisture conditions altered hydrologic mitigation effectiveness. The basins reduced flashiness when comparing inflow to outflow and pre-construction to outflow hydrographs, including reducing peak flow magnitudes by >80% on average. Basin performance was not strongly affected by precipitation magnitude or antecedent conditions, though the range of precipitation magnitudes sampled was limited. Construction costs were higher than previously reported projects, but annual maintenance costs were similar and no higher than costs to maintain an equivalent landscaped area. Results indicate that bioretention basins effectively mitigate peak flow and flashiness, even in flash-flood-prone environments, which should benefit downstream ecosystems. The results provide a unique assessment of bioretention basin performance in flash-flood-prone environments and can inform the optimization of cost-effectiveness when implementing GSI at watershed scales in regions with current or future similar precipitation regimes. [ABSTRACT FROM AUTHOR]

The high irrigation water demand of coconut trees in semiarid regions makes rational use crucial for crop sustainability. Additionally, it produces residues that could improve the soil water holding capacity. This research aimed to evaluate the application of coconut shell biochar to an irrigated dwarf green coconut palm orchard. The study was carried out from January 2019 to December 2021 at Campo Experimental do Curu, Paraipaba, Brazil, belonging to Embrapa Agroindústria Tropical. The experiment consisted of a completely randomized design with five treatments and four replications and included the application of 0, 5, 10, 20, or 40 g of biochar per kg of soil, equivalent to 0.0 kg, 0.5 kg, 1.0 kg, 2.0 kg or 4.0 kg of biochar per plant, respectively. The following biometric variables were evaluated: number of leaves per plant (NL), plant height (PH), number of leaflets per leaf (LFT), canopy diameter (CD) and fruit production: number of bunches per plant (NB), number of fruits per plant (NF), volume of coconut water per fruit (CWF) and total soluble solids (TSS) (°Brix), as well as the daily soil moisture average. The results showed beneficial effects on the number of leaves per plant, fruits per plant, soil moisture and irrigation water productivity in terms of liters per fruit, liters per coconut water and fruits per cubic meter (m3) applied with ideal biochar doses estimated to be 1.40 kg, 1.72 kg, 1.79 kg, 1.56 kg, 1.48 and 1.68 kg of biochar per plant, respectively. [ABSTRACT FROM AUTHOR]

Acute shortage of water resources and high unproductive water losses are the key problems of irrigated agriculture in arid regions. One of the possible solutions is to optimize soil water retention using natural and synthetic polymer water absorbers. Our approach uses the HYDRUS-1D design to optimize the placement of organic water absorbents such as peat and composite hydrogels in the soil profile in the form of water-storing capillary barriers. Field testing of the approach used a water balance greenhouse experiment with the cultivation of butternut squash (butternut squash (Cucurbita moschata (Duchesne, 1786)) under sprinkler irrigation with measurement of the soil moisture profile and unproductive water losses in the form of lysimetric water outflow. In addition, the biodegradation rate of organic water absorbents was studied at the soil surface and at a depth of 20 cm. Organic capillary barriers reduced unproductive water losses by 40–70%, retaining water in the topsoil and increasing evapotranspiration by 70–130% with a corresponding increase in plant biomass and fruit yield. The deepening of organic soil modifiers to the calculated depth not only allowed capillary barriers to form, but also prevented their biodegradation. The best results in soil water retention, plant growth and yield according to the "dose-effect" criterion were obtained for a composite superabsorbent with peat filling of an acrylic polymer matrix. The study showed good compliance between the HYDRUS design and the actual efficiency of capillary barriers as an innovative technology for irrigated agriculture using natural and synthetic water absorbents. [ABSTRACT FROM AUTHOR]

Rabbit meat is tender, high in protein, low in fat and cholesterol, and offers several nutritional benefits. However, it has a stronger taste and can be challenging to cook. The global rabbit industry has been developing steadily, and China's total rabbit meat production has exceeded half of the world's total production in 2021. Along with the progress of the production process, the meat of the nutrition and taste at the same time, to improve smell also can get better control, solved the problems met in rabbit meat production. This article discusses the attributes of rabbit meat and outlines the deodorization, texture adjustment, and water retention techniques currently used in rabbit meat processing, aiming to offer a theoretical foundation for the advancement of rabbit meat processing technology. [ABSTRACT FROM AUTHOR]

The capacity of soil to retain water and make it available to plants is an essential soil functions for the sustainability of terrestrial ecosystems. A lot of progress has been made in estimating water retention and availability as a function of soil texture. On the other hand, a lower effort has been dedicated to seeking correlations between plant-available water (AW) and soil compaction. In this study, we compiled a dataset with 2479 records from experiments conducted in Brazilian soils to evaluate the relationship between AW and bulk density (BD). The dataset was split into sub-datasets defined by soil textural classes to reduce the effect of texture on AW–BD relationships. In each sub-dataset, AW–BD relationships were described by linear regression. In general, there was a weak association between AW and BD. The strongest correlations were found in the Silty Loam (R2 = 0.26) and Loam (R2 = 0.13) classes. However, the partitioning of the overall dataset by textural classes was not effective to eliminate the effect of texture on AW–BD relationships. Still, the data showed that soil compaction may increase or reduce AW. Nevertheless, more experimental research is needed to bring a better understanding of how AW is affected by changes in BD. [ABSTRACT FROM AUTHOR]

Urban nature-based solutions (NBSs) are widely implemented to collect, store, and infiltrate stormwater. This study addressed infiltration rate as a measure of the performance of bioretention solutions. Quick scan research was conducted, starting with mapping over 25 locations of implemented green infrastructure in Riga, Latvia. Basic information, such as location, characteristics, as well as photos and videos, has been uploaded to the open-source database ClimateScan. From this, eight bioswales installed in the period 2017–2022 were selected for hydraulic testing, measuring the infiltration capacity of bio-retention solutions. The results show a high temporal and spatial variation of infiltration rate for the bioswales, even those developed with similar designs: 0.1 to 7.7 m/d, mean 2.0 m/d, coefficient of variation 1.0. The infiltration capacity decreased after saturation: a 30% to 58% decrease in infiltration rate after refilling storage volume. The variation in infiltration rate as well as infiltration rate decrease on saturation is similar to other full-scale studies done internationally. The infiltration rate of most bioswales falls within the range specified by international guidelines, all swales empty within 48 h. Most bioswales empty several times within one day, questioning the effectiveness of water retention and water availability for dry periods. The results are of importance for stakeholders involved in the implementation of NBS and will be used to set up Latvian guidelines for design, construction, and maintenance. [ABSTRACT FROM AUTHOR]

The article outlines the physiological and biochemical parameters of 10 exotic accessions of two local cultivars of grass pea (Lathyrus sativus L.). By analyzing the plant leaf spectrophotometrically at the bud formation phase, exotic sample Bio-520 x 1330 showed chlorophyll а of 21.47 mg/ml, Bio (520 x Bio) x 273 with chlorophyll b of 12.79 mg/ml, and Ratan x IG 135481 had carotenoids at 5.57 mg/ml. Based on total pigments, Ratan x 1307 gave the highest value (30.24 mg/ml), while in the flowering phase, Ratan x IG 135481 showed chlorophyll а of 21.37 mg/ml, Ratan x 2125 with chlorophyll b of 16.51 mg/ml, and Prateek x IG 140034 with carotenoid of 6.02 mg/ml. For Ratan x 2125, the total pigments were 37.14 mg/ml, with the highest values for all traits. In the ripening phase, Bio 520 x 1330 with chlorophyll а (11.92 mg/ml), Ratan x 2125 with chlorophyll b (16.63 mg/ml), 1330 x 2125 with carotenoid (4.04 mg/ml), and Ratan x 2125 with total pigments (25.62 mg/ml). Higher protein content resulted in seeds of Prateek x IG 140035 (26.3%), Bio (520 x Bio) x 273 (26.1%), and Ratan x 1307 (26.0). Besides, 1330 x 2125 has biochemical elements (Li, B, Na, Cu, and As), Ratan x 2125 (Mg, K, Ca, Ti, Sr, and Ba), Ratan x IG 135481 (Rb, Mo, and Cd), and Prateek x IG 140034 with chemical elements (Al, Fe, and Ag). The control Lalmikor provided B, Mn, Rb, and Ag higher than other exotic samples. [ABSTRACT FROM AUTHOR]

Air-fall pyroclastic soil deposits usually display a loose fabric composed of alternating layers of ashes and pumices. Such deposits, when lying on steep slopes, represent a major geohazard due to the occurrence of landslides. This is the case of the carbonate massifs in Campania (southern Italy), a wide landslide-prone area of approximately 400 km2 covered with pyroclastic soils. In such cohesionless deposits, the additional shear strength provided by soil suction in unsaturated conditions is important for ensuring slope stability and can be jeopardized by soil wetting during rainwater infiltration. This paper provides a comprehensive view of the hydraulic and shear strength characteristics of different layers of pyroclastic deposits at different sites in Campania, revealing a broad view of their similarities and differences. To that end, some datasets from previous studies and novel data are gathered, linking the index properties, the hydraulic behavior of the soils and the contribution of suction to the shear strength of the studied materials. Two types of ashes at different positions within the stratigraphic sequence are identified: ashes interbedded between pumice layers, where landslide failure surfaces usually occur, and altered ashes in contact with the bedrock, which affects water leakage from the overlying soil profile. The former show quite uniform characteristics, and this allowed testing some predictive models for the assessment of the unsaturated shear strength of pyroclastic ashes in the absence of direct measurements. In contrast, the latter may exhibit significantly different behaviors, with great variability in hydraulic and mechanical properties. [ABSTRACT FROM AUTHOR]

Applying green infrastructure measures helps to retain water in the land during wet periods, which in turn makes it more available during periods of drought. Water retention reduces the volume of rainwater that transforms into surface runoff, allowing for the increase in the intensity of evapotranspiration and infiltration, which helps to establish a catchment with a balanced hydrologic cycle that's effectively more resistant to the consequences of climate change. With increasing popularity of introducing low impact development (LID) solutions in highly urbanised catchments characterised by a high runoff coefficient, it is important also to reduce rainwater runoff in residential areas with lower density of housing. This work presents a numerical assessment of green infrastructure (green roofs, raingardens, permeable paving and rainwater harvesting) performance in increasing retention in a catchment area consisting of single-family houses. The numerical model of potential residency in Ożarów, Poland was developed in SWMM 5.2. software, replicating local conditions with input infiltration data collected through on site and laboratory testing, as well as data gathered during a period of registering local evaporation and precipitation conditions. After running a series of simulations of three rain events, varying in their duration and intensity, the model was enhanced with green infrastructure solutions by the utilisation of LID Controls option in SWMM. With rainfall simulations resulting in varying rainwater outflow hydrographs and with differences in the volume of collected rainwater outflow, the results of LID application were consistent with the reduction of the peak rainwater outflow (reduction rate 61.90-67.99%), as well as the decrease in rainwater outflow volume (reduction rate 61.17-62.12%). This research promotes the hydrologic effectiveness of introducing green infrastructure in low density housing establishments. [ABSTRACT FROM AUTHOR]

Planting vegetation is a sustainable and eco-friendly method for shallow slope stabilization. However, in water-limited regions, this method is facing challenges such as retarded vegetation growth, which leads to unprotected soils. Biopolymers, with potentials in both vegetation growth promotion and soil strength enhancement, are therefore tested in this study with regard to their possibility in assisting soil reinforcement with vegetation through vegetation cultivation and direct shear tests. Both sugar-based and protein-based biopolymers improved water availability to growing plants and nutrient uptake. The most suitable polysaccharide xanthan gum was adopted to further explore the effects of treatment conditions (i.e., blending content) and external environment (i.e., precipitation) on the vegetated soil performance. Under a variety of water supplies, xanthan gum with a medium blending content of 0.5% (i.e., with respect to dry soil mass) led to the most substantial improvement in the ability to resist shear loading. This indicates that the appropriate dosage of biopolymers used at the initial stage of plant growth should provide moderate bond strength between soil particles, while not impeding root penetration. Supported by the obtained results, biopolymers are suggested to be used in combination with plants for soil reinforcement for the best efficiency. [ABSTRACT FROM AUTHOR]

Laborious and time-consuming tests are required for the determination of the soil–water characteristic curve (SWCC), often leading to the adoption of estimation methods. To answer the challenge of SWCC prediction, numerous pedotransfer functions (PTF) have been developed. Yet, previous studies have not considered the special behavior of bimodal tropical soils. These materials present dual porosity that is generally attributed to particle aggregation. This paper presents a novel PTF, specifically designed for bimodal tropical soils and based on artificial neural networks (ANNs). The model was trained and tested utilizing a database that was assembled containing soils from tropical regions of Brazil and featuring data for the grain-size distribution (GSD), consistency limits, and SWCC. Natural and remolded soils were included in the training database, but no distinction between soil conditions was made in the ANN. GSDs in the aggregated and disaggregated states were used to offer information to the ANN regarding the effect of particle aggregation on the water retention. The developed model was able to reproduce the typical SWCC shape of bimodal soils. Predictions for the degree of saturation were moderately correlated with directly measured data, with a coefficient of determination of 0.69. The air-entry value and residual suction of the macropores proved to be the most difficult SWCC attributes to be estimated. The ANN presented superior performance when compared to other PTFs not designed specifically for bimodal tropical soils, such as the Arya-Paris and ROSETTA models. It can be concluded from the obtained results that the developed ANN architecture and general approach showed a high capability to capture the main features of the SWCC. [ABSTRACT FROM AUTHOR]

Study Region: The northern slope of Qinling Mountains (NQL) is an important water retention (WR) area in China, which guarantees the utilization of water resources in the plain area. However, the effects of significant changes in climate and land cover on WR have not been quantitatively studied in recent years. Study Focus: In this study, we quantified the relative impacts of climate and land cover changes on WR at NQL and predicted the future changes of WR under different climate scenarios (SSP2–4.5 and SSP5–8.5). New Hydrological Insights for the Region: The results indicated that WR in NQL has exhibited an overall increase from 1985 to 2020 at a rate of 1.10 mm/a, with climate and land cover change explaining 86.3 % and 13.7 % of this change, respectively. Although precipitation has increased since 1998, the compounding effects of land cover change and precipitation intensity increase have led to a slight decline of WR magnitude and efficiency due to their offsetting impacts. Under future climate change, the WR capacity changes in the SSP2–4.5 are relatively stable, while the significant increase in temperature under the SSP5–8.5 lead to a decreasing trend in WR efficiency. In addition, we proposed an indicator framework to evaluate WR using WR efficiency and baseflow lag time. Our results may provide valuable insights for sustainable utilization and scientific management of water resources.

The water retention service of the forest ecosystem has ecological functions such as adjusting the climate and maintaining the ecological water balance. The Qinghai-Tibet Plateau is an alpine region. Due to its high altitude and harsh environment, it is difficult to manually observe the water retention in the field, and it is impossible to better evaluate the water retention function. In order to better obtain the water retention in the alpine region, hyperspectral technology is introduced and applied to the acquisition of surface vegetation information, and the water retention in a specific area is obtained by constructing a model. In this study, the Bayi District of Nyingchi Prefecture was used as the research area. The main tree species in the study area are Picea likiangensis var. linzhiensis(PLVL), Quercus aquifolioides(QA), Pinus densata(PD) and Rhododendron nivale(RN). In actual situations, it is not easy to directly obtain water retention information, so a model can be found to quantitatively express the relationship between leaf spectrum and water retention. Then based on the leaf spectrum to invert the water retention. In order to study the quantitative relationship between different vegetation and water retention, each type of vegetation collects leaf samples and water retention data at 30 sampling points. Use ASD Fildsoec Handheld spectrometer to obtain hyperspectral data. Seven band indexes of red edge, green peak, NDVI, NDWI, EVI, WBI and NDPI were selected, and the relationship between vegetation band index and water conservation was fitted through many kinds of regression models. Comparing the fitting results, construct water retention prediction model. The interception of vegetation canopy, litter water holding capacity and soil water content are obtained through experiments. The sum of the three represents the water retention capacity of vegetation. The reflectance spectra of the four types of vegetation leaves all show similar regularities, and the difference in the visible light band is not obvious. The near-infrared to mid-infrared bands show four distinct water absorption bands, with the highest reflectivity in the red to near-infrared bands (700 nm-1400 nm). The reflectance of the four types of vegetation varies across different spectral bands, with the reflectance levels exhibiting the characteristic order of QA > PD > PLVL ≈ RN. Comparing the fitting results of different regression models with seven waveband parameters, the R2 of the four types of vegetation are higher in the regression models of EVI and NDPI, and reach a significant level. According to the regression model corresponding to each kind of vegetation, the water retention prediction model is composed, and the simulation accuracy is tested by R2 and RMSE. The overall simulation accuracy R2 is greater than 0.7 and the RMSE is basically less than 10 t·hm−2, indicating that the forecasting model has a good forecasting effect and the model can effectively estimate the water retention of the forest ecosystem.

Background: Superabsorbent polymers (SAPs) have a remarkable ability to absorb significant quantities of water. However, their absorption capacity is significantly reduced when exposed to saline solutions, such as urine, due to the polyelectrolyte effect and charge screening. Methods: In this study, we demonstrate a zwitterionic superabsorbent polymer (ZSAP) with excellent salt-water absorption and retention capacities. ZSAP was synthesized by grafting a copolymer of p(sulfobetaine methacrylate-co-2-hydroxyethyl methacrylate) (p(SBMA-co-HEMA)) onto an acrylic acid (AA)-based hydrogel via free-radical polymerization. The introduction of zwitterionic SBMA significantly enhances the hydrophilicity of the polymer, particularly in a saline solution due to the anti-polyelectrolyte effect, thereby accelerating the rate of salt absorption. Additionally, the hydroxyl groups from HEMA facilitate the formation of covalent bonds with the AA network membrane through esterification, effectively mitigating polymer leaching. The hydration/dehydration behaviors of linear polymers were measured using the dynamic vapor sorption (DVS) method. Moreover, the salt-water absorption capacity, centrifuge retention capacity (CRC), and absorbency under load (AUL) of ZSAP with various SBMA moieties and copolymer dosages were comprehensively evaluated in a 0.9 wt% sodium chloride solution. Additionally, the water retention under different temperatures and polymer leaching of ZSAP were investigated. Significant Findings: The copolymer p(SBMA-co-HEMA) not only demonstrates a high salt-water absorption rate at 90% RH in a 0.9 wt% NaCl solution but also exhibits superior water retention at 0% RH compared to the AA polymer. Moreover, the ZSAP exhibits superior salt-water absorption capacity and AUL in a 0.9 wt% NaCl solution compared to conventional AA-based SAP. Additionally, the introduction of the hydroxyl moiety from the p(SBMA-co-HEMA) copolymer reduces free polymer leaching from ZSAP. This work presents an approach for the development of new SAP with high salt-water absorption and retention.

Soilless substrate stratification is increasing in popularity in the greenhouse and nursery industry globally. The concept of stratifying substrates entails stacking two substrates with different physiochemical properties to augment vertical moisture balances and redistribution for quicker establishment, greater root growth, and quicker time to market. Stratified substrate research to date has estimated or assumed that the static physical properties of a stratified system as the mean of the individual strata components. No research to date has verified or rejected this assumption using a stratified column. The research herein measured the static physical properties of 1) peatlite (85% peat: 15% perlite), 2) unprocessed

Nutrient leaching is a common issue in sandy soils. The use of hydrogel polymers can mitigate this problem by enhancing soil water retention. This study aims to assess the effect of hydrogel polymer application on nutrient leaching in sugarcane-cultivated soil and its impact on plant growth over a 196-day cycle. Parameters examined include soil water retention (%), nutrient leaching (N, P, K, Ca, Mg, and S) analyzed through the water collected after natural drainage, as well as various plant growth parameters such as stem height and diameter, and fresh and dry stem and leaf mass. The highest soil water retention was observed in treatments with 1.5 and 2.0 g kg-1 of hydrogel polymer. Regarding nutrient leaching, the treatments with 1.5 and 2.0 g kg-1 of hydrogel polymer exhibited the lowest values, resulting in reductions of over 85% for all accumulated nutrients leached by the end of the crop cycle. The application of hydrogel, especially at higher doses, also enhanced sugarcane growth, notably increasing fresh stem mass. These results suggest that hydrogel polymers could serve as a sustainable solution for controlling nutrient leaching in sugarcane cultivation, contributing to the sustainable development of agriculture and environmental preservation.

Background. Moss cover plays a decisive role in increasing soil moisture in forest ecosystems. Bryophytes with high water content can significantly reduce water evaporation from the soil surface and retain it for an extended time. Under the influence of environmental conditions, mosses change the shape and organization of moss turfs thus regulating the efficiency of moisture absorption and retaining. Therefore, it is essential to establish the differences in the water exchange strategy of epigeic dominant moss species depending on the environmental conditions in reserved and anthropogenically disturbed forest ecosystems. Materials and Methods. The research was carried out using the dominant epigeic, typical forest moss species Plagiomnium cuspidatum (Hedw.) T. J. Kop. and P. ellipticum (Brid.) T. J. Kop. from experimental plots of forest ecosystems, which differed in water and temperature regimes and light intensity. We determined the peculiarities of the influence of adaptations of moss turf morphological structure, individual plant’s physiological functional traits, and their metabolic osmoprotective changes based on the leading indicators of their water exchange (coefficients of water retention, water recovery, and drought resistance). Results. It was established that humidity and light intensity in forest ecosystems changed the shape and organization of moss turfs, i.e., the height of individual shoots in the turf and the density and size of leaves. The predominance of the generative or vegetative type of moss reproduction led to significant changes in the morphology of shoots, physiological functional traits of plants, and the density of the turf structure, which was regulated due to the increase in airstream turbulence and wind penetration, absorption and evaporation of water. The hydration of moss tissues was maintained due to the rise in the total carbohydrate content as well as the soluble fraction content primarily in the vegetative shoots. Conclusions. Mosses adapted to variable microclimatic conditions of forest ecosystems due to endohydricity and water retention mechanisms in external capillary spaces, i.e., changes in height, shape, and density of turfs, shoot morphology, various ratios of fertile to sterile plants, and their physiological functional traits. The internal regulation of water potential of cells was ensured by an increased concentration of osmoprotectors (carbohydrates, primarily their soluble fraction).