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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]

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]

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]

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]

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]

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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]

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]

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]

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]

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]

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 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]

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]

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]

This study investigates the influence of air exposure time on the erodibility of intertidal mud flats, emphasizing the role of evaporation in altering sediment strength and cohesion. Through a comprehensive approach combining laboratory experiments, fieldwork, and numerical modelling, it explores the dynamic interactions between sediment properties and environmental conditions. The research reveals that drying significantly reduces sediment erodibility, with pronounced effects observed during the initial hours of air exposure. Laboratory tests demonstrate a direct correlation between drying time and increased yield stress for both artificial and field-derived mud samples. Field observations further support these results, showing spatial and temporal variations in water content and shear strength across various locations on a tidal flat. The study emphasizes the critical impact of mud content on water retention and the subsequent effect on sediment stability. The incorporation of drying time into erosion formulations within a numerical model highlights the importance of considering evaporation processes in predicting the morphological evolution of tidal flats. This research contributes to a better understanding of sediment transport dynamics in intertidal zones, offering insights into the mechanisms driving the growth and stability of mud flats. It underscores the necessity of integrating evaporation effects into cohesive sediment transport models to enhance the accuracy of predictions concerning the erosion and accretion of intertidal environments. [ABSTRACT FROM AUTHOR]

Post-recycling sodium polyacrylate (SPA) derived from the selective recycling of personal hygiene products was tested as a potential key component of soil modifiers. Recycled SPA in combination with layered aluminosilicate (halloysite) with the sorption capacity of fertilizers allows for the creation of a fully functional, original system responsible for both water retention in soil and controlled dosing of fertilizers. The use of post-recycling SPA (possibly partially supplemented with virgin SPA) is advantageous for the natural environment. The results of different water types retention in post-recycling SPA (deionized water, rainwater, tap water) are discussed. The most beneficial effects of R-SPA swelling and water accumulation are achieved when it comes into contact with rainwater. The clear impact of Mg2+ ions on the sorption capacity of R-SPA introduces the need for a technological compromise between the solution composition (N, P, K or N, P, K, Mg) affecting its fertilization value and the possibility of obtaining maximum R-SPA swelling. The sorption capacity of R-SPA can be slightly increased by using R-SPA/V-SPA mixtures, but R-SPA still plays a decisive role in this system. The possibility of technological adjustment of the leaching rate of fertilizer components under dynamic conditions using different combinations of (R-SPA/V-SPA)/HAL was demonstrated by column tests. [ABSTRACT FROM AUTHOR]

This numerical study presents six three-dimensional (3D) cathode flow field designs for a passive air-cooled polymer electrolyte membrane (PEM) fuel cell to enhance heat removal and H2O retention. The data collected are evaluated in terms of water content, average temperature, and current flux density. The proposed cathode flow field designs are a straight baseline channel (Design 1), converging channel (Design 2), diverging channel (Design 3), straight channel with cylindrical pin fins (Design 4), trapezium cross-section channel (Design 5), and semi-circle cross-section channel (Design 6). The lowest cell temperature value of 56.67 °C was obtained for Design 2, while a noticeable water retention improvement of 6.5% was achieved in a semi-circle cathode flow field (Design 5) compared to the baseline channel. However, the current flux density shows a reduction of 0.1% to 1.2%. Nevertheless, those values are relatively small compared to the improvement in the durability of the fuel cell due to heat reduction. Although the modifications to the cathode flow field resulted in only minor improvements, ongoing advancements in fuel cell technology have the potential to make our energy landscape more sustainable. These advancements can help reduce emissions, increase efficiency, integrate renewable energy sources, enhance energy security, and support the transition to a hydrogen-based economy. [ABSTRACT FROM AUTHOR]

The unsaturated permeability of cracked compacted fine soil is a key parameter in geotechnical engineering, particularly when analyzing water flow through the soil in various conditions. The compaction affects the saturated and unsaturated permeability by reducing porosity. However, cracks can appear by shrinkage and growth during desiccation, which obviously leads to macro-porosity (a process during which the soil acquires a high level of double porosity). The development of a crack network influences the suction (as negative water pressure) and then the unsaturated permeability. The current paper aims to analyze the role of the crack network (considered as macropores) on the unsaturated permeability, by quantifying the network based on the Crack Intensity Factor (CIF). The unsaturated permeability is given as a function, separately of CIF and suction. The experimental results may be considered constructive for soil modeling. Regarding the birth of the first crack, it occurred when the suction reached a value near to that of the air entry suction. Since the first crack appeared, primary cracks were developed and then followed by secondary cracks. The obtained experimental results of WRC and Kunsat for cracked compacted clay are beneficial in managing the design of the geotechnical structure stability and the environmental issues of water diffusion. CIF increases with suction, which is augmented during the drying process demonstrating a decrease in the moisture content. After 21 hours of desiccation, CIF ended up reaching a value of 4%. It is generally recognized that cracks create preferential pathways for water flow, whereas their geometry and distribution influence how water moves through the soil. Modeling the impact of cracks on permeability may involve considering factors like crack width, orientation, and connectivity. In this paper, a simple model was proposed to predict the unsaturated permeability as a function of suction with different CIF values with the material being assumed as a double porosity soil. [ABSTRACT FROM AUTHOR]

Improving water-holding functions is an important purpose of sustainable forest management. However, few studies have examined whether there are differences in water-holding capacities between the forests dominated by trees associated with different mycorrhizal types and what are the main factors leading to the differences. Here, we investigated seven parameters of water-holding capacities of soils, litter, and canopy interception in 210 forest plots (10 m × 10 m). The plots were equally divided into three forest types associated with mycorrhizal types, including AM plots (arbuscular mycorrhizal trees > 75% in dominance), ECM plots (ectomycorrhizal trees > 75%), and AM + ECM plots (between 25 and 75%). We calculated tree diversity (richness, Shannon–wiener index, Simpson index, evenness), community structure (diameter at breast height, height, under branch height, density, neighborhood comparison-U, uniform angle index-W, and mingling index-M), and soil physics (soil bulk density and field water content). The results showed that: (1) ECM-dominated communities increased 1.6–2.0-fold in the litter water-holding capacities than those of AM and AM + ECM. The canopy interception of the ECM community was the highest (0.97 mm), significantly higher than that of the AM + ECM community (0.58 mm). (2) The ECM community had lower field soil water-holding capacity (p < 0.05) but 42–78% higher soil non-capillary water capacity than that of AM and AM + ECM (p < 0.05). (3) ECM forests were characterized by low tree species evenness, big-sized trees, and low bulk density, favoring increasing ecosystem water-holding capacities. Moreover, increasing ECM tree dominance enhanced the contribution of community structure to water-holding variations. (4) ECM trees increased ecosystem water-holding functions by direct effects (mainly on the litter) and indirect effects from soil physics (mainly on the soils) or tree size (mainly on the canopy) regulations. This study highlighted that ECM trees enhanced water-holding capacity, providing important information for planting and managing temperate water conservation forests. [ABSTRACT FROM AUTHOR]

The swelling behaviors and water retention of superabsorbent sand-fixing materials prepared from acrylic acid/acrylamide copolymer (AA/AM) and acid-modified attapulgite under ultrasonic treatments and different pH conditions were investigated. The results demonstrated that a suitable amount of attapulgite can effectively improve the absorption capacity and saltwater performance. The superabsorbent achieved the highest absorptions of 1257.54 g/g and 209.45 g/g in distilled water and a 0.9 wt% NaCl solution, and a higher water absorbency occurred over a wide pH range of 5~9 when the ultrasonic power was 200 W and the attapulgite content was 10%. The addition of attapulgite could significantly increase the water absorption and retention. [ABSTRACT FROM AUTHOR]

The BEST (Beerkan Estimation of Soil Transfer parameters) method was used to compare the hydraulic properties of the soils in two Long-term Agroecosystem Experiments (LTAEs) located at the FIELDLAB experimental site of the University of Perugia (central Italy). The LTAE "NewSmoca" consists of a biennial maize-durum wheat crop rotation under integrated low-input cropping systems with (i) inversion soil tillage (INT) or (ii) no-tillage (INT+) and (iii) under an organic cropping system with inversion soil tillage (ORG). ORG and INT+ involve the use of autumn-sown cover crops (before the maize cycle). Pure stand durum wheat was grown in INT and INT+, while a faba bean–wheat temporary intercropping was implemented in ORG. The LTAE "Crop Rotation" consists of different crop rotations and residue management, a continuous soft winter wheat and biennial rotations of soft winter wheat with maize or faba bean. Each rotation is combined with two modes of crop residue management: removal or burial. For INT+, despite the high-bulk density (>1.50 g/cm3), we found that conductivity, sorptivity and available water are comparable to those of INT, probably due to a more structured and efficient micropore system. ORG soils show the highest conductivity, sorptivity and available water content values, probably due to the recent spring tillage occurring in the wheat inter-row with the faba bean incorporation into the soil. For LTAE Rotation, the residue burial seems to influence the capacity-based indicators positively. However, the differences in the removal treatment are minor, and this could be due to the inversion soil tillage, which limits the progressive accumulation of organic matter. [ABSTRACT FROM AUTHOR]

The guar gum-polyethylene glycol (GG-PEG) and cellulose acetate-polyethylene glycol (CA-PEG) hydrogel beads have been synthesized using crosslinking agent polyethylene glycol with drop cast method. The newly fabricated beads have been characterized by FTIR, FESEM, TGA and swelling studies. Water retention, water holding, and soil porosity tests have been conducted on both hydrogel beads. The results showed that the swelling ratios for GG-PEG and CA-PEG were 350 g/g and 250 g/g, respectively. At high pressures, GG-PEG retained 20% more water than untreated soil, whereas CA-PEG retained 17.5%. The soil's water-holding capacity improved to 16.05% when treated with GG-PEG, compared to 9.69% with CA-PEG. The porosity of soil increased to 69.45% in the case of GG-PEG hydrogel beads and 65.17% in the case of CA-PEG when compared to untreated soil. The biodegradable studies of the hydrogel beads showed that GG-PEG was more susceptible to degradability since it was a natural polymer. As a result, GG-PEG is more efficient than CA-PEG, and this study demonstrates how natural polymers may be employed as superabsorbents to improve soil qualities by serving as conditioners. [ABSTRACT FROM AUTHOR]

Mineral mining often results in changes to the soil environment, reducing the sustainability of the surrounding environment. Restoring the physical and chemical properties of soil in post‐tin‐mining areas on the tropical island of Belitung, Indonesia, has been a laborious process after more than 10 decades of land reclamation. We aimed to determine which parameter of the soil properties was responsible for the slow recovery process and if there were other properties that indicated more rapid changes. We measured the physical, chemical, and biological properties of soils of different periods in the post‐tin‐mining areas. We sampled soil from three areas: 0, 1, and 6 years after mining and an adjacent natural forest as a reference site. The soil water content, hydraulic conductivity, bulk density, particle distribution, mineral content, and soil microbial composition were measured in the field and analyzed in the laboratory. The soil showed a fine particle loss and despite the absence of clay, water‐holding capacity was significantly increased in the 6‐year‐old soil. Organic carbon increased by 0.2% after 6 years of reclamation. Copper, iron, manganese, and zinc in the soils fluctuated less. Minimal amounts of Pb and Cd were found. Soil bacterial communities shift with land age. Actinobacteria were dominant a few years after mining, while Proteobacteria colonized the mined area after 6 years. This study examined the more profound changes in the soil properties of tropical post‐tin‐mined land. Soil and bacterial characteristics can be used as markers to monitor the progress of land rehabilitation. [ABSTRACT FROM AUTHOR]

Amphioctopus neglectus is a species of octopus that is favored by consumers due to its rich nutrient profile. To investigate the influence of different thawing methods on the quality of octopus meat, we employed four distinct thawing methods: air thawing (AT), hydrostatic thawing (HT), flowing water thawing (FWT), and microwave thawing (MT). We then explored the differences in texture, color, water retention, pH, total volatile basic nitrogen (TVB–N), total sulfhydryl content, Ca2+–ATPase activity, and myofibrillar protein, among other quality indicators in response to these methods, and used a low-field nuclear magnetic resonance analyzer to assess the water migration that occurred during the thawing process. The results revealed that AT had the longest thawing time, leading to oxidation-induced protein denaturation, myofibrillar protein damage, and a significant decrease in water retention. Additionally, when this method was utilized, the content of TVB–N was significantly higher than in the other three groups. HT, to a certain extent, isolated the oxygen in the meat and thus alleviated protein oxidation, allowing higher levels of Ca2+–ATPase activity, sulfhydryl content, and springiness to be maintained. However, HT had a longer duration: 2.95 times that of FWT, resulting in a 9.84% higher cooking loss and a 28.21% higher TVB–N content compared to FWT. MT had the shortest thawing time, yielding the lowest content of TVB–N. However, uneven heating and in some cases overcooking occurred, severely damaging the protein structure, with a concurrent increase in thawing loss, W value, hardness, and shear force. Meanwhile, FWT improved the L*, W* and b* values of octopus meat, enhancing its color and water retention. The myofibrillar protein (MP) concentration was also the highest after FWT, with clearer subunit bands in SDS-PAGE electrophoresis, indicating that less degradation occurred and allowing greater springiness, increased Ca2+–ATPase activity, and a higher sulfhydryl content to be maintained. This suggests that FWT has an inhibitory effect on oxidation, alleviating protein oxidation degradation and preserving the quality of the meat. In conclusion, FWT outperformed the other three thawing methods, effectively minimizing adverse changes during thawing and successfully maintaining the quality of octopus meat. [ABSTRACT FROM AUTHOR]

The contemporary development of cities necessitates the implementation of modern systems, particularly with regard to the drainage of rainwater and melted snow from road surfaces. Due to the prevalent use of paved surfaces in urban areas, it is crucial to explore solutions that facilitate water retention at the point of occurrence. A key element is the use of biologically active surfaces. When designing specific solutions, it is vital to first review the current water and road regulations. An analysis based on these regulations was conducted to investigate the potential for increasing water retention in pedestrian buffer lanes in the Old Town area of Płock. [ABSTRACT FROM AUTHOR]

Herein, a semi-interpenetrating network (semi-IPN) hydrogel (SH/PNA) was prepared by simple free radical polymerization using N-isopropylacrylamide and 2-acrylamide-2-methylpropanesulfonic acid as monomers, poly(ethylene glycol) dimethacrylate as a crosslinking agent, and sodium alginate and humic acid as filled biomolecules. Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and rheometer were used to characterize the structure and properties of the samples. The effect of feeding ratios on the gel mass fraction and swelling properties of the SH/PNA hydrogel was explored to optimize its preparation conditions. The swelling behavior under different pH and temperatures was investigated. The experimental result showed that the SH/PNA hydrogel had excellent water absorption capacity and pH/temperature dual responsiveness. Moreover, SH/PNA hydrogel was used as a carrier of urea to prepare slow-release and water-retention fertilizer by in situ loading method, and slow-release properties of urea in water and soil were measured. Taking into account its good ability for controlled release and water retention, the WSRF was expected to be a promising low-cost, environmentally friendly fertilizer that can be used in agriculture and horticulture. [ABSTRACT FROM AUTHOR]

Soil management significantly affects soil structure. Tillage and grassland renovation may have destructive influences, while conversion of arable land to grassland can improve pore structure and related soil functions. In crop rotations including perennial grasses, soil structure is affected by these counteracting processes. This work aimed to quantify the impacts of different soil management practices on the structure of boreal clay soils. We studied intact topsoil samples taken from two locations by X‐ray computed microtomography, image‐based flow simulations and water retention measurements. At both locations, adjacent field areas with two contrasting soil management histories were compared. Both locations had at least a 30‐year‐old grassland site, which was compared to arable soils either under no‐till management with annual crop rotation or conventional tillage with crop rotation including perennial grasses. Both imaging and water retention measurements showed significant differences in the soil macropore structure between the long‐term grassland and arable no‐till soil such that macroporosity and hydraulic conductivity of the long‐term grassland were higher than those of soil under agricultural production. On the contrary, at the second study location, differences between long‐term grassland and cultivated fields were minor and the long‐term grassland exhibited lower macroporosity. Our results confirm that soil management affects the macropore structure of boreal clay soil and that no‐till annual cropping and periodically tilled crop rotation including perennial phases exert different effects on the soil structure as compared with long‐term grassland. [ABSTRACT FROM AUTHOR]

Superabsorbent materials (SAPs) are crosslinked polymer networks composed of ionic and non-ionic monomers. SAPs can absorb and retain water solutions up to several hundred times their own weight. As a result of swelling, they form a gel that is insoluble in water, considered safe and decomposes over time. This review focuses on the synthesis, degradation and chemical composition of SAP materials, with particular emphasis on chemical substances that are soluble in water and can migrate into the environment. Numerous applications of natural and synthetic hydrogels in agriculture and the reclamation of degraded areas in preventing erosion, retention water, reducing leaching of colloidal soil components and plant protection products, fertilisers and mineral salts into surface waters have been described. The influence of SAPs on the microbial activity of soils is described. New trends in the search for environmentally friendly SAPs made of modified biopolymers and waste materials are presented, which not only increase yields, but also ensure sustainable agro-environmental development. [ABSTRACT FROM AUTHOR]

In this study, sulfated cellulose pulps (SCPs), synthesized via environmentally friendly methods by supporting sulfamic acid and urea on wood-derived cellulose pulps (CPs), were used to prepare completely dispersed cellulose nanofibers (CNs). CP is a sustainable natural polymer that is biodegradable, nontoxic, and relatively inexpensive. Additionally, cellulose nanofibers prepared from CPs have attracted attention as promising natural nanofibers with various useful properties. Therefore, sulfation of CP with sulfamic acid and urea was investigated as a method for preparing completely dispersed CNs. The SCPs were synthesized in high yields through the sulfamic acid ≥ urea (molar ratio) reaction system at 393 K for 30 min. The SCPs contained sulfate groups with 0.79–1.33 mmol g−1 at hydroxy groups of C6, and C2 and/or C3 positions of cellulose, maintained long fibers and exhibited a 429–880 degree of polymerization (DP), retaining 60% more DP than the original CP. Some SCPs attained a maximum water retention value of approximately 3000%, suggesting a swollen fiber structure. Completely dispersed sulfated CNs with a fiber diameter of approximately 3–4 nm could be prepared by defibrating these SCPs. The swollen fiber structure observed in the SCPs reduced the defibrated energy and time required to achieve complete dispersion. [ABSTRACT FROM AUTHOR]

Copyright of Indonesian Journal of Agricultural Sciences / Jurnal Ilmu Pertanian Indonesia is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Using slow-release fertilizer is one of the sustainable strategies to improve the effectiveness of fertilizers and mitigate the environmental pollution caused by excess usage of fertilizer. In this study, a slow-release urea fertilizer with water retention and photosensitivity properties was prepared by a two-step method. It was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and an infrared camera. This fertilizer can prolong the release period of urea, improve water-retention capacity of soil, and carry out photothermal conversion under illumination. Comparing four release kinetics models, the Ritger–Peppas model was the best fitting model for releasing behavior in soil, and diffusion followed the Fickian mechanism. The application of fertilizer on winter wheat was carried out to intuitively evaluate the fertilizer's effects on promoting plant growth and resisting water stress. Thus, this study provides a new strategy for improving fertilizer utilization rate and maintaining soil moisture, which will be beneficial for sustainable agriculture. [ABSTRACT FROM AUTHOR]

Extreme climates and the unpredictability of the weather are significant obstacles to agricultural productivity. This study is the first attempt to explore the capacity of nanobonechar (NBC) for promoting climate-smart agriculture. A pot experiment was performed on maize (Zea mays L.) under a deficit irrigation system (40, 70, and 100% irrigation rates) using different soil application rates of the NBC (0, 0.5, 1, and 2% wt/wt). Additionally, the CO2–C efflux rate and cumulative CO2–C were measured in an incubation experiment. The results indicated the best performance of the 1% NBC treatment under a 70% irrigation rate in terms of the fresh and dry weights of maize plants. Total PO43− and Ca2+ were significantly higher in the plants grown in the NBC-amended soil as compared to the control, showing a gradual increase with an increase in the NBC application rate. The improved productivity of maize plants under a deficit irrigation system was associated with enhanced water-holding capacity, organic matter, and bioavailability of cations (Ca2+, K+, and Na+) and anions (PO43− and NO3−) in the soils amended with NBC. The CO2–C efflux rate and cumulative CO2–C emissions remain higher in the NBC-amended soil than in the un-amended soil, pertaining to the high contents of soil organic matter emanating from the NBC. We conclude that NBC could potentially be used as a soil amendment for promoting maize growth under a water stress condition. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The filter paper (FP) method, a cost-effective, versatile, and convenient approach, has found extensive application in analyzing fine-grained soils, enabling the successful measurement of a broad spectrum of total and matric suctions. However, using the FP method in sand with a limited range of suction profiles has been notably underrepresented in the existing literature. Therefore, this study investigated the applicability of the contact FP method in establishing soil water retention curves (SWRCs) using five distinct FP calibration curves for 10 poorly graded sands. Among these calibration curves, the one presented by Chandler yielded the highest suction values, which were followed by those of ASTM. Furthermore, the FP results were subjected to fitting with a mathmatical model, which led to the observation that the overall trends in the obtained SWRCs displayed smooth sigmoidal shapes, resulting in a complete and coherent SWRCs. The SWRC results of five sand samples were assessed through validation against the hanging column technique (HCT) results, indicating a high degree of concordance and affirming the suitability of the FP method for sands characterized by a limited suction profile. Notably, the entire range of suction values fell within the 0.01–20 kPa range based on the calibration curves presented by Chandler and ASTM for all the examined sand samples, except sands 9 and 10. Furthermore, the suction values were unobtainable using the two aforementioned calibration curves within the ranges of 0.01–1.47 kPa and 0.01–0.172 kPa. [ABSTRACT FROM AUTHOR]

The ecological restoration (ER) project significantly affects the water retention function in the Taihang Mountain area. However, a comprehensive understanding of the water retention effects in different ER project areas still needs to be improved. In this study, we employed the integrated valuation of ecosystem services and trade‐offs (InVEST) model to evaluate the differences in water retention among different ER project areas. Additionally, we used the structural equation model to explore the influence of various factors on water retention. The results showed the following: (1) The total amount of water retention in the Taihang Mountain area increased yearly from 2000 to 2020, with an 85.25% increase in 21 years. The water retention function showed a trend of transferring to a higher level. (2) The forest land restoration project showed the highest average water retention capacity, followed by the grassland restoration project, which together provided 61.12% of the water retention capacity in the ER areas. Forest land restoration project was found to have the most potential in improving water retention, while grassland restoration was more efficient. The water retention capacity of a 21‐year‐old artificial forest could only reach 70.92% of the natural forest. Cropland restoration mode increased the water retention by 22.85% compared with non‐ecological engineering areas. (3) The enhancement of water retention function in the study area resulted from multiple factors, among which precipitation and root depth were the most critical variables. (4) According to the structural equation model, the impact of natural factors on water retention accounted for 74.33%, and ecological engineering had a greater impact on water retention in the hilly zone. The ER project significantly increased water retention capacity. The results provide scientific support for improving water retention function and optimizing ER projects in semi‐arid areas of China. [ABSTRACT FROM AUTHOR]

Purpose: Degraded soils are unable to perform key functions and, thus, it is very important to develop effective reclamation methods. To restore utility or natural values to degraded ecosystems, various compounds are applied. In this study, the impacts of additives of various origin and composition on Polish (Eutric Cambisol) and Bulgarian (Epicalcic Chernozem) soils were compared. The main goal of the study was to make a comprehensive assessment of the validity of using popular soil additives in a real context. Materials and methods: Physicochemical and hydrophysical parameters including pH, variable surface charge, porosity, specific surface area, wettability, sorption capacity relative to trace metals, and water retention of soils were taken into account. Surface charge and porosity of soils were determined using potentiometric titration and nitrogen adsorption/desorption method, respectively. Wettability was measured by sessile-drop method, whereas water retention, using different matric potentials (pF curves). Sorption study on trace metals included isotherm and kinetics determination as well as experimental data modeling. Results and discussion: The most positive effect on soil surface charge, porosity, wettability, and cadmium (Cd) sorption was observed for synthetic zeolite, zeolite-carbon composite, and vermicompost. This effect was noted only for Polish soil characterized by poor porosity, low content of organic carbon, and moderately acidic reaction. For eroded Bulgarian soil, the condition of which was definitely better, the impact of modifiers was not spectacular. Among tested amendments, only divergan increased water retention properties of both examined soils significantly. Conclusions: Zeolite, zeolite-carbon composite, and vermicompost can be apply for degraded soils of low organic carbon content, poor porosity, and moderately acidic pH to improve their physicochemical parameters and sorption ability toward trace metals. Divergan should be used to improve water retention of degraded soils during their reclamation. [ABSTRACT FROM AUTHOR]

The ink‐bottle effect, resulting from the heterogeneous pore structure, plays a significant role in the hydraulic hysteresis of water retention behavior. Experimental evidence indicates that volumetric deformation extensively influences the hysteresis characteristics of the soil‐water retention curve (SWRC). This paper presents a physical–based model that aims to simulate the contraction of the hysteresis loop in the SWRC during soil compression by considering the evolution of the ink‐bottle effect. Within the proposed model, it is assumed that the suction increment is consumed in two distinct manners: to overcome the ink‐bottle effect and to alter soil saturation. As soil undergoes compression, the ink‐bottle effect weakens, resulting in a reduced proportion of suction consumed in counteracting this effect. To quantitatively describe the impact of ink‐bottle effect evolution on SWRC hysteresis, a novel concept known as hysteresis potential is introduced, which is defined as the difference in natural logarithmic values of suction between the drying and wetting curves at a given saturation. Finally, the proposed model was validated using five sets of experimental data, affirming its capability to capture the hysteresis loop evolution in SWRC attributed to the weakening of the ink‐bottle effect during soil compression. [ABSTRACT FROM AUTHOR]

Bryophytes were traditionally ignored in most studies of forest ecosystem processes, or they were included with litter or soil. In the last few decades we have begun to understand their many roles that permit them to be ecosystem engineers. This review serves to pull together many scattered sources into a single source on the many contributions bryophytes can perform as ecosystem engineers and to support what several authors have already stressed: that bryophytes should not be treated as a single functional group. It puts bryophytes in perspective in terms of richness and biomass, then explores their roles as ecosystem engineers; that is, their roles in altering diversity, nutrient cycling, carbon sequestering, water retention, erosion depression, temperature modification, fire protection, fire and logging recovery, interactions with mycorrhizal fungi, effects on seed germination, and seedling survival. Interactions with other species are mentioned, but those regarding animals are largely omitted in favor of more detailed description of their relationships with trees throughout the world. Bryophytes provide both positive and negative interactions with forest trees, depending on the tree species, the ecosystem, and the bryophyte species. It is clear that different bryophytes have many different functional roles in sustaining the forest and making it suitable for germination, seedling success, and maintaining the mature forest. This review indicates those important roles and how they apply differently according to both tree and bryophyte species, and that different management practices are needed, depending on both bryophyte species and tree species, to sustain different forest types. [ABSTRACT FROM AUTHOR]