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The present study investigates the feasibility of using polysaccharide enriched extracts (PEEs) from the red seaweed Schizymenia dubyi as coating materials in the preparation of controlled release triple superphosphate (TSP) fertilizers. Initially, the polysaccharide was isolated, extracted, and further characterized by gas chromatography and infrared analysis to determine its chemical composition and its partial structure. Results of chemical and spectroscopic analysis indicated that galactose, glucuronic acid, and glucose were the main components of the polysaccharide with a molecular weight of 2805 KDa. It can be suggested that this polysaccharide could be a sulfated glucuronogalactan. After that, the viscosity of the coating polysaccharide solution at different concentrations was conducted to determine the low and high polysaccharide concentrations that can be easily sprayed. After the spray coating process using different concentrations (1.8% and 2.5% w/v) and application cycles (from C1 to C4), the resulting coated fertilizer beads were chiefly characterized in terms of morphology, release kinetics in water and soil, and water retention properties. Results of the phosphorus release kinetics in water showed an effective effect for the slow release behaviour of the fertilizer. Increasing the concentration of the matrix additionally delays the release of P, and the best results were obtained with the formulation 2.5% -C4 which released 75% P after 5 to 7 days versus 2 days for the uncoated TSP. The same tendency was also recorded in soil release kinetics and weight losses. The soil water retention was also improved with the coated fertilizers, with over 4% more water retention than the uncoated fertilizers over 28 days. These findings showed that the polysaccharide-coated TSP fertilizer had multiple agronomic features and could be a promising candidate for various potential applications in agriculture. [ABSTRACT FROM AUTHOR]

The crosslinked poly(acrylic acid-co-acrylamide)-grafted deproteinized natural rubber/silica ((PAA-co-PAM)-DPNR/silica) composites were prepared and applied as coating materials for fertilizer in this work. The crosslinked (PAA-co-PAM)-DPNR was prepared via emulsion graft copolymerization in the presence of MBA as a crosslinking agent. The modified DPNR was mixed with various contents of silica (10 to 30 phr) to form the composites. The existence of crosslinked (PAA-co-PAM) after modification provided a water adsorption ability to DPNR. The swelling degree values of composites were found in the range of 2217.3 ± 182.0 to 8132.3 ± 483.8%. The addition of silica in the composites resulted in an improvement in mechanical properties. The crosslinked (PAA-co-PAM)-DPNR with 20 phr of silica increased its compressive strength and compressive modulus by 1.61 and 1.55 times compared to the unloaded silica sample, respectively. There was no breakage of samples after 80% compression strain. Potassium nitrate, a model fertilizer, was loaded into chitosan beads with a loading percentage of 40.55 ± 1.03% and then coated with the modified natural rubber/silica composites. The crosslinked (PAA-co-PAM)-DPNR/silica composites as the outer layers had the ability of holding water in their structure and retarded the release of fertilizer. These composites could be promising materials for controlled release and water retention that would have potential for agricultural application. [ABSTRACT FROM AUTHOR]

The influence of a single species cover crop on soil hydraulic properties during one growing season are well known. However, the influence of multi-year and multi-species cover crops on soil physical and hydraulic properties are not yet fully understood. The current study was set up using a completely randomized block design during 2021 and 2022, it investigated the effects of a multi-species cover crop (winter wheat (Triticum aestivum L.), crimson clover (Trifolium incarnatum L.), triticale (Triticale hexaploide Lart), hairy vetch (Vicia villosa), oats (Avena sativa), and cereal rye (Secale cereale L.)) on bulk density, soil organic carbon, saturated hydraulic conductivity, pore-size distribution, and volumetric water content at 0, -0.4, -1, -2.5, -5, -10, -20, -33, -100, and -1 500 kPa soil water pressures. The soil samples were collected in 10 cm increments from the soil surface down to 30 cm. After 2 years, the results showed that cover crop reduced bulk density by 17% as compared with no cover crop management. Further, the cover crop-induced increases in soil organic carbon as well as in macro- and mesoporosity led to 23, 25, and 28% increases in volumetric water content at 0, -33, and -100 kPa soil water pressures respectively, relative to no cover crop management. When comparing the two years of the study, under cover crop management alone, saturated hydraulic conductivity was higher in 2021 as compared to 2022, which suggests that cover crop-induced improvements in some hydraulic properties may not be proportional over time. In general, cover crops improved the measured soil hydraulic properties after 2 years and this has the potential to be beneficial for improving soil water storage. [ABSTRACT FROM AUTHOR]

The destructive environmental impacts of large-scale agriculture are further aggravated by drier climate in the Danube-Tisza sand region, where soil fertility is low, water retention is very limited and groundwater levels are steadily dropping. The prevention of wind erosion is a central task in raising the level of ecosystem services. Among other related services the enrichment of the blown-sand soil with organic matter (enhancing carbon sequestration), the improvement of soil structure and water retention capacity and achieving higher soil biodiversity are major objectives. The international Diverfarming project (2017-2022) within the EU Horizon 2020 Program focussed on the impacts of crop diversification and low-input practices. In the experiments intercropping with different annual crops was investigated and its influences on some provisioning and regulating ecosystem services were evaluated in an asparagus field in Jakabszállás. Although the findings point out the decisive role of soil moisture conditions, the positive impacts of diversification are also remarkable. The local farmer agrees that crop diversification improves soil quality, but he denies that it would directly influence farm competitiveness, which is primarily dependent on the costs of fertilization, plant protection and labour. Further analyses are needed to prove the benefits of diversification through enriching soil microbial life and the possible reduction of fertilizer use while water demand is kept at a low level and the same crop quality is ensured. [ABSTRACT FROM AUTHOR]

The aim of this article is to present the basic theses about the function and potential of infiltration pits under culvert mouths on forest roads. The methodology consisted of a combination of literature review and own in situ experiments. Experimental verification was carried out on sections of forest roads on two training forest enterprises (TFE) at Kostelec nad Černými lesy and Masarykův les Křtiny (Czech Republic). At each location, two infiltration pits were built in a paired design with a uniform retention volume. One of the pits was always located under a pipe culvert. The control pit was located approx. 30 m far from it, in the same pedological and vegetation conditions without a centralized inflow. Measurements from the study period (autumn 2022) indicated that the infiltration pits under the culverts had unexpectedly low efficiency in retaining and infiltrating surface runoff. Mostly, due to the fact that in the analyzed period the surface runoff was minimal, even though precipitation did occur. During the study period, the infiltration pits did not reach the expected potential to support the hydric regime of the landscape. [ABSTRACT FROM AUTHOR]

• Clay coated poly-bed can retain water and influence fish growth and production during dry seasons. Further depth replications can specify depth level more accurately in the future. Summer ponds in north-west Bangladesh are suffering from sandy soil and drought. From January to December 2017, the University of Rajshahi, Bangladesh, conducted an experiment to improve seasonal ponds' water retention capacity and productivity. In nine seasonal ponds, polythene and clay were used on the bottom of three treatments (T 1 , T 2 , and T 3). Selected five controlled ponds were used to compare water depth and production. While the average water depth was above 3 feet (0.91 m) in controlled ponds only for 6 months, polythene-based model ponds lengthened water holding capacity with average water depths of 6.23 feet (1.87 m), 5.71 feet (1.71 m) and 5.07 feet (1.52 m) in T 1 , T 2 and T 3 , respectively throughout the year. The average net production of the research ponds in eight months was 20.68 kg/decimal whereas it was only 4.35 kg/decimal for controlled ponds. T 1 exhibited 2.07 fold greater water depth and 4.75 fold greater productions than controlled ponds. Net production (5908.59±72.72 kg/ha/8month) of T 1 was significantly (P < 0.05) higher than T 2 and T 3. Thus, using polythene and clay in the pond bottom and covering it with water up to 8 feet (2.4 m) deep, will increase the water holding capacity and production of seasonal ponds. [ABSTRACT FROM AUTHOR]

Salinity is detrimental to soil health, plant growth, and crop productivity. Understanding salt tolerance mechanisms offers the potential to introduce superior crops, especially in coastal regions. Root system architecture (RSA) plasticity is vital for plant salt stress adaptation. Tall fescue is a promising forage grass in saline regions with scarce RSA studies. Here, we used the computer-integrated and -automated programs EZ-Rhizo II and ROOT-Vis II to analyze and identify natural RSA variations and adaptability to high salt stress at physiological and genetic levels in 17 global tall fescue accessions. Total root length rather than the number of lateral roots contribute more to water uptake and could be used to separate salt-tolerant (LS-11) and -sensitive accessions (PI531230). Comparative evaluation of LS-11 and PI531230 demonstrated that the lateral root length rather than the main root contributed more towards the total root length in LS-11. Also, high water uptake was associated with a larger lateral root vector and position while low water intake was associated with an insignificant correlation between root length, vector, and position. To examine candidate gene expression, we performed transcriptome and transcription analyses using high-throughput RNA sequencing and real-time quantitative PCR, respectively of the lateral and main roots. The main root displayed more differentially expressed genes than the lateral root. A Poisson comparison of LS-11 vs PI531230 demonstrated significant upregulation of PLASMA MEMBRANE AQUAPORIN 1 and AUXIN RESPONSE FACTOR 22 in both the main and lateral root, which are associated with transmembrane water transport and the auxin-activated signaling system, respectively. There is also an upregulation of BASIC HELIX-LOOP-HELIX 5 in the main root and a downregulation in the lateral root, which is ascribed to sodium ion transmembrane transport, as well as an upregulation of THE MEDIATOR COMPLEX 1 assigned to water transport in the lateral root and a downregulation in the main root. Gene-protein interaction analysis found that more genes interacting with aquaporins proteins were upregulated in the lateral root than in the main root. We inferred that deeper main roots with longer lateral roots emanating from the bottom of the main root were ideal for tall fescue water uptake and salt tolerance, rather than many shallow roots, and that, while both main lateral roots may play similar roles in salt sensing and water uptake, there are intrinsic genomic differences.

Interactions of humans with the environment are strongly related to land use and land cover changes (LULCCs). In the last decades, these changes have led to a degradation of ecosystem services, including water regulation and flood control. In the Alpine areas of Austria, land cover changes have increased flood risk since the middle of the 19th century. In this paper, we assess the influence of these long-term land use changes on the landscape’s ability to retain water using the qualitative Water Retention Index (WRI). The changes are thereby evaluated on the basis of the historical (1826–1859) and present (2016) land cover situation, which is to our knowledge the first high-resolution and regional application of the WRI. The results show that the water retention potential mimics the mountainous characteristic and features. Except for areas strongly dominated by settlement areas, the highest retention potentials are found in valley floors and the lowest values are depicted along the main Alpine complex. In low-lying areas, the retention decreased by over 10%. It was found that this decrease can be mostly attributed to settlement expansion. Above 1,250 m, land use transformations led to slightly increasing water retention values owing to the transformation of wasteland or glaciers to stagnant waters and to the expansion of forest and grassland in high elevations. This examination allows for a holistic and spatially distributed LULCC impact assessment on the landscape’s water regulation capacities and offers valuable high-resolution information for future land use planning and sustainable land development.

Heavy metals in landfill leachate are easily adsorbed by soil particles, causing serious threats to human health and surrounding environments. Mining and metallurgy activities are intensive in Northwest China, thereby enlarging threats. The aim of the present study is to enhance our knowledge about the linkage between the microstructural evolution of the loess soil induced by lead contamination and the macro air and liquid permeability properties. A series of air and liquid permeability tests on the uncontaminated and Pb-contaminated loess specimens were conducted. Their air and liquid permeability properties were evaluated on the basis of Darcy’s law and the soil–water retention curves, respectively. The microstructural evolution, when subjected to low and high Pb2+ concentrations, was assessed using scanning electron microscopy (SEM), X-ray diffraction (XRD), mercury intrusion porosimetry (MIP), and zeta potential tests. The intrusion of Pb2+ decreases the absolute zeta potential ζ, which in turn leads to a more distinct agglomerated structure and higher intrinsic permeability. Moreover, the dedolomitization and associated cerussite (PbCO3) precipitation are deemed as the main cause of micropore clogging, whereas the corrosion of the cement between soil particles by H+ shows a good correspondence to an increase in the number of mesopores. With the concentration of Pb2+ increasing from 0 to 2,000 mg/kg, the proportion of micropores decreases from 37.9% to 15.1%, and the proportion of mesopores increases from 17.3% to 53.3%. In addition, the air entry value decreased from 19.5 to 12.8 kPa, indicating that the water retention behavior decreased. The findings highlight the impacts of lead contamination on the microstructure and macro permeability properties and give some design guideposts to heavy metal-contaminated site remediation.

Soil moisture reserves are a key factor in maintaining soil fertility and all other related ecosystem services (including carbon sequestration, soil biodiversity, and soil erosion control). In semiarid blown-sand areas under aridification, water preservation is a particularly crucial task for agriculture. The international Diverfarming project (2017–2022), within the EU Horizon 2020 Program, focused on the impacts of crop diversification and low-input practices in all pedoclimatic regions of Europe. In this three-year experiment conducted in the Pannonian region, the impact of intercropping asparagus with different herbs on some provisioning and regulating ecosystem services was evaluated in the Kiskunság sand regions. Relying on findings based on a range of measured physical and chemical soil parameters and on crop yields and qualitative properties, advice was formulated for farmers. The message drawn from the experiment is somewhat ambiguous. The local farmers agree that crop diversification improves soil quality, but deny that it would directly influence farm competitiveness, which primarily depends on cultivation costs (such as fertilization, plant protection, and labour). Further analyses are needed to prove the long-term benefits of diversification through enriching soil microbial life and through the possible reduction of fertilizer use, while water demand is kept at a low level and the same crop-quality is ensured.

Addressing climate change necessitates a conscious transition toward sustainable infrastructure solutions. Our vision involved transforming an experimental area into the University Experimental Center. This experimental building serves as a model for gray infrastructure implementation, taking into account its dimensions, layout, flooring, and material composition. Our study aims to compare the retention capacities of various types of vegetated roofs, as determined by different legislations. The findings indicate that the outcomes vary based on the regulations used. This variation subsequently influences the design of associated infrastructures, such as rainwater drainage systems, and the design of stressed structures. This is due to the impact of water quantity on the thermal response of a stressed structure. The water used to irrigate the vegetation layer, along with the water retained by the upper roof, has a positive impact on both the building and its surroundings. Initially, the system comprised two functional components: vegetated roofs and a reference roof. The integrated experimental roof shell, in conjunction with the frame, forms an autonomous system. This system serves as a segment for quantifying water retention, humidity, and temperature across diverse green infrastructure substrates. We analyzed the thermal response of experimental roof constructions and monitored the influence of water and precipitation. Our results indicate that the height of the substrate affects not only the retention capacity but also the thermal response of the vegetated roof.

This investigation aimed to assess the effects of whey protein hydrolysate (WPH) on the oxidative stability of protein and the ability of Scomberomorus niphoniu surimi balls to retain water after repeated freeze–thaw (F–T) cycles. Ten percent natural whey peptides (NWP), 5% WPH, 10% WPH, 15% WPH, 0.02% butyl hydroxyl anisole (BHA), and a control group that did not receive any treatment were the six groups that were employed in the experiment. The cooking loss, water retention, total sulfhydryl content, and carbonyl content of each group were all measured. Notably, it was found that the surimi balls’ capacity to hold onto water and fend off oxidation was enhanced in a dose-dependent manner by the addition of WPH. Furthermore, the results showed that the 15% WPH added to the surimi balls effectively decreased protein oxidation in the F–T cycles and ameliorated the texture deterioration of surimi balls induced by repeated F–T, laying a theoretical foundation for the industrial application of WPH in surimi products.

To address the problems of inadequate water and fertilizer retention performance of the substrate, which results in the waste of water and fertilizer resources and then contributes to existing agricultural non-point source pollution, this study selected raw materials with different water retention performances for substrate compounding and explored their water retention performance and impact on the growth, yield and quality of strawberries. The experimental setup utilized the strawberry cultivar ‘Hongyan’ as the test subject and incorporated different proportions of vermicompost, coconut bran, biochar and humic acid into the organic fertilizer. A total of 12 treatment groups were formed across three gradients, involving different proportions of vermicompost with 0.05, 0.10 and 0.15 proportions of coconut bran/biochar and 0.05, 0.15 and 0.20 proportions of humic acid. To evaluate the water retention performance, uniform water and fertilizer regulations were applied. The results revealed that the treatment groups T4 (vermicompost:coconut bran = 0.5:0.1) and T5 (vermicompost:biochar = 0.5:0.1) exhibited higher water absorption multiplicity, lower water infiltration rates, and better water retention performances, but there was no significant difference between the two treatment groups. Among them, T4 could effectively improve the nutrient content of the substrate, and the substrate nitrogen-use efficiency (NUE) increased by 5.80% compared with CK2. Also, plant total nitrogen (TN) and total phosphorus (TP) uptake increased by 81.18% and 4.74%, respectively, compared with CK2, which in turn promoted the growth and development of the plant and improved the fruit yield and quality to a certain extent. Meanwhile, T4 had the highest urease and catalase activities, with sucrase activity ranking second only to T1. In contrast, T5 demonstrated greater effectiveness in improving the average fruit weight and maximum fruit weight, registering increases of 22.98% and 36.22% compared to CK2, respectively, but the effect on the total yield was less pronounced. A comprehensive evaluation of strawberry growth found that the T4 treatment was superior. In conclusion, the ratio of vermicompost and coconut bran at 0.5:0.1 improved and promoted the substrate water retention performance and strawberry growth.

Introduction: Urbanization is increasing in the world and the world's urban population is becoming denser in cities. One of the effects of urbanization is the increase in the percentage of impervious surfaces in these areas. Today, many important cities in the world pay attention to the concept of sustainable development in order to reduce the effects of their city development on the quality and quantity of runoff and use modern green management technologies, including the best management methods and development methods with minimal side effects. A green roof is a multi-layered system that covers the roof and balcony of a building with vegetation and by absorbing and keeping part of the rain, and by influencing the processes of evaporation and transpiration, purification, the volume and intensity of the peak flow of runoff, the dimensions The drainage system reduces the downstream and improves the quality of air and water, preserves the beauty of the city and prevents the wastage of building energy.Material and methods: This research was conducted as a field experiment in the Faculty of Agriculture of Zanjan University. The test period was from April to August of 2017. In this research, the effect of the use of super absorbent (zeolite) on the amount of water absorption and retention, the maximum and minimum volume of runoff, the volume of runoff, sediment and the start time of the runoff resulting from rainfall in the rain intensity of 35, 45, 55, 65 and 75 mm/h has been investigated on a green roof with a slope of 5%, in a cold dry climate.Results and discussion: Based on this, with the increase in the intensity of rainfall, the volume of runoff also increases, and the volume of runoff in barren soil is more than the rest of the treatments, and its downward trend is soil containing 1% zeolite, soil containing 3% zeolite, and cultivated soil. Be Also, the volume of runoff increased with the increase in rainfall intensity and the highest value of runoff volume belongs to barren soil. The sediment measured in the runoff also increases with the increase in the intensity of precipitation in the treatments, except for the grass treatment.Conclusion: Barren soil has a very high volume of runoff due to the sealing of its surface layers and clogging of pores. Adding zeolite to the soil significantly reduced the volume of runoff and retained more water than barren soil. The rate of erosion in soil with 1% zeolite was high and the rate of erosion was the lowest in grass. In barren soil, because the penetration of water is low, after a short period of time after the rain, the water flows as runoff, but zeolite has the property and characteristic that when added to the soil, the time for the start of runoff is lengthened by 3%.

In order to effectively prevent the spontaneous combustion of coal and make up for the shortcomings of existing fire-extinguishing materials, a new type of high water-resistant capsule material was developed by adding gluconolactone based on sodium alginate and light calcium carbonate. First, by analyzing the influence of different material content on the molding time and water retention performance of high-water capsules, it is concluded that high-water capsule with a ratio of 2%SA+0.5%PCC+1%GDL has better fluidity and slow molding speed, 2.5%SA+1%PCC+1%GDL high-water capsule has stronger water retention and faster forming speed. Then, the temperature programmed experiment was used to analyze the change of the concentration of the iconic gas during the heating process of the coal sample. The results showed that the CO production of the coal sample with the high water capsule was reduced, and the temperature of the C2H4 gas increased, indicating that the high water capsule has a certain inhibition effect on coal oxidation.

Saline conditions govern soil behavior during evaporation, thereby affecting the water budget in semi-arid regions. This research examined the effects of saline pore fluid on soil behavior during evaporation. The results indicated volumetric reductions of about 5% for silty sand and about 15% for lean clay. The evaporative flux for silty sand decreased from 26 mg/m2∙s to 22 mg/m2∙s in StageII, remained at a constant flux in StageIII, and decreased to 13 mg/m2∙s in StageIV. The air entry and residual suction values were found to be 5 kPa and 100 kPa, respectively, and the total suction of about 5000 kPa merged with matric suction near the Stage II/Stage III boundary. The swell–shrink curve (SSC) was J-shaped with the only void ratio decrease in Stage II. In contrast, the evaporative flux for lean clay decreased from 30 mg/m2∙s to 15 mg/m2∙s in StageII, to 10 mg/m2∙s in StageIII, and then to 5 mg/m2∙s in StageIV. The air entry and residual suction values were 5 kPa and 2000 kPa, respectively, and the total suction during Stage II and Stage III ranged from 1000 kPa to 6000 kPa, with an average value of 3500 kPa. The SSC showed a major void ratio decrease in Stage II, marginal decrease in Stage III, and no decrease in Stage IV. Under high demand, the evaporative flux for silty sand was constant at 180 mg/m2∙s in StageIII and decreased to 50 mg/m2∙s in Stage IV, whereas it decreased for the lean clay from 230 mg/m2∙s to 145 mg/m2∙s in StageII, to 95 mg/m2∙s in StageIII, and then to 25 mg/m2∙s in StageIV. For both soils, the total water loss was found to be six times higher than that under low demand.

This study assessed the applicability of chitin nanocrystals prepared by 2, 2, 6, 6-Tetramethyl-1-Piperidine-1-oxyl radical (TEMPO)-mediated oxidation in traditional papermaking coating color systems. The α-chitin nanocrystals (CTNCs) with different carboxyl content, size, and morphology were prepared from crab shells by alkali pretreatment and TEMPO-mediated oxidation in the water at pH 10, and then the ratio of CTNCs to latex was applied to traditional coating color system to replace part of latex. The results showed that when the amount of NaClO added as co-oxidant in the oxidation was 15.0 mmol/g of chitin, the carboxyl content of alkali-pretreated CTNCs was up to 0.76 mmol/g. The amount of carboxyl groups presented a linear relation with the degree of individualization of nanocrystals and dispersion. When the ratio of latex to CTNCs was 90꞉10, the water retention value of the coating was 92% lower than that of the pure latex system, and the rheological property was better. The relationship between the addition amount of CTNCs and the surface strength and the coverage of coating layers were also studied, and results showed that when the ratio of latex to CTNCs was 95꞉5, the surface strength was the highest of 1.45 m/s, and the coverage of coating layers rate reached the highest of 78%.

Frosting behavior and dynamic defrosting characteristics of horizontally oriented hybrid surfaces with heterogeneous wettability were experimentally investigated. The developed hybrid surfaces with superhydrophobic patterns built on superhydrophilic background integrated the properties of frost retardation under frosting conditions and fast surface cleaning of residual water upon defrosting. Four types of hybrid surfaces with different pattern spacings were tested in this work. Hybrid surfaces exhibited superior anti-frosting performance compared with that of a bare copper surface but lower than a complete superhydrophobic surface. During defrosting process, surface energy gradient and Laplace pressure gradient enabled by heterogeneous wettability on hybrid surfaces could drive the mobile slush composites on superhydrophobic regions move to superhydrophilic areas to achieve quick cleaning even in the absence of gravity force. The proportion of surface clean time of one full cycle duration on hybrid surfaces was as low as 32.2%–41.5%. Compared to complete superhydrophobic and bare copper surfaces, hybrid surfaces exhibited a significant enhancement on defrost efficiency due to larger three phase contact line length on evaporation-mediated surface cleaning performance, especially the SSH-3 surface, achieving the largest defrost efficiency within the present frost mass range.

Abstract Droplet arrays show great significance in biosensing and biodetection because of low sample consumption and easy operation. However, inevitable water evaporation in open environment severely limits their applications in time‐consuming reactions. Herein, inspired by the unique water retention features of leaves, it is demonstrated that an open droplet array on patterned organohydrogel surface with water evaporating replenishment (POWER) for ultrawide time‐range biosensing, which integrated hydrophilic hydrogel domains and hydrophobic organogel background. The hydrogel domains on the surface can supply water to the pinned droplets through capillary channels formed in the nether organohydrogel bulk. The organogel background can inhibit water evaporation like the wax coating of leaves. Such a unique bioinspired design enables ultrawide time‐range biosensing in open environment from a few minutes to more than five hours involving a variety of analytes such as ions, small molecules, and macromolecules. The POWER provides a feasible and open biosensing platform for ultrawide time‐range reactions.

Non-point sources of water pollution caused by agricultural crop production are a serious problem in Czechia, at present. This paper describes a new approach for the mutual delineation and assessment of different pollution sources where the critical points method is used to identify the origin of contamination and the source areas. The critical points, i.e., sites presenting the entry of quick surface and drainage runoff into waters, are classified into three (for surface pollution sources using a WaTEM/SEDEM model) or four (subsurface = drainage sources via the catchment-measures need index) categories, respectively. This enabled us to prioritize the most endangered areas at different scales, ranging from the third-order catchments to very small subcatchments, and to design the appropriate combination of control measures to mitigate surface and drainage water runoff, with these being the main drivers of associated pollution. This methodology was applied to a study conducted in the Czech Republic within the entire Vltava River basin, with a total area of 27,578 km2, and utilized in depth to assess a 543 km2 catchment of the Vlašimská Blanice River. When the effect of the designed surface runoff control measures system had been assessed for sediment transport through outlet profiles of the fourth-order catchments, the average reduction reached 43%. The total reduction in the subsurface transport of nitrogen within the fourth-order catchments was 24%. The approach and results are planned to be projected into river basin management plans for the Vltava River basin. Nevertheless, a thorough reassessment of current legislations and strategies is needed to enable the broader adoption of mitigation measures and sustainable management patterns within agricultural landscapes. [ABSTRACT FROM AUTHOR]

Introduction Monitoring the changes in physical and hydraulic properties and stability of growth media due to root growth effects and wetting and drying cycles is important. Wetting and drying cycles can probably change physical characteristics, availability of water, air and nutrients for the plant and, as a result, might affect the growth and yield of the greenhouse plants. The growth period greatly affects the physical characteristics of the growth substrates; therefore, the watering of growth substrates should be managed according to these changes to avoid improper irrigation. Materials and Methods In this study, 14 growth media were prepared from individual substrates with different volumetric ratios. In order to evaluate the changes of growth media over the time (i.e., during consecutive irrigation events) in the greenhouse, 10 wetting and drying cycles were applied on the growth media in the lab. Several physical indicators including easily available water (EAW), air after irrigation (AIR), water buffering capacity (WBC) and water holding capacity (WHC) of the growth media were determined before and after the wetting and drying cycles. Besides, the subsidence, decrease of mass and decomposition of the growth media were determined over the time. Total porosity (TP), bulk density (BD), particle density (PD), pH and electrical conductivity of the mixtures were measured as well. Results and Discussion The pH values in the growth media varied from 5.72 to 6.94. The maximum pH value was related to sawdustsugarcane bagasse biochar produced at 300◦C vermiculite-zeolite, and wheat straw-vermiculite substrates, and the minimum value was related to the cocopeat-perlite substrate. The values of EC in the growth media varied from 0.21 to 1.43 dS mR². The highest and lowest EC values among the growth substrates were related to date palm bunches-vermiculite-rockwool and rockwool (0.2)-perlite substrates, respectively. The bulk density (BD) values of the growth media varied in the range of 0.163-0.401 Mg m-3. The values of total porosity (TP) of the growth media varied in the range of 64.8-82.8%v/v. The highest TP was related to the cocopeat-perlite substrate. The TP values of most of the substrates were greater than 70%v/v. The average values of EAW in the growth substrates ranged from 0.123 to 0.272 cm³ cm-3. The highest EAW was related to the sawdust-sawdust biochar produced at 500 °C vermiculite-zeolite substrate. The application of wetting and drying cycles increased EAW in most of the growth media. Therefore, it can be stated that the time had a positive effect on the EAW in most of the growth media. The average values of AIR before and after the application of wetting and drying cycles for the growth media varied in the range of 0.063-0.240 cm-3 cm³. The highest value of this indicator was observed in the sawdustdate palm bunches biochar produced at 300°C vermiculite substrate. In all substrates (with the exception of the sawdust-sawdust biochar produced at 500°C vermiculite-zeolite), the AIR increased after wetting and drying cycles. The range of WHC values before and after applying wetting and drying cycles was 0.4530.699 cm3 cm-3. The highest WHC belonged to the wheat straw-vermiculite substrate. The WHC values of five growth media, including cocopeat-perlite, decreased due to the application of wetting and drying cycles, and the WHC values of nine growth media decreased. The most stable substrate after the wetting and drying cycles was rockwool-sawdustvermiculite. The effect of time on the quantity of WBC was positive, so that with the application of wetting and drying cycles, the WBC values of most of the substrates increased. In all substrates, subsidence and dry weight reduction were observed after the wetting and drying cycles. These changes were low for the substrates with a high volumetric ratio of inorganic materials. The least change among the growth substrates in terms of decomposition (dry weight reduction) was related to the completely inorganic substrate rockwool (0.1)-perlite (%0.17). The most stable substrate in terms of subsidence after wetting and drying cycles was the rockwoolsawdust-vermiculite, which has a large volumetric ratio of individual inorganic substrates. The highest subsidence was observed in the substrates containing wheat straw (wheat straw-vermiculite and date palm bunches biochar produced at 300◦C wheat straw-vermiculite). The organic matter content in all the growth substrates decreased over time (after wetting and drying cycles). The decrease of organic matter in the substrates can be related to the decomposition of organic materials as a result of wetting and drying cycles. Conclusion The BD, TP, EAW and WHC of the majority of growth media were in the optimal ranges and for some mixtures even better than cocopeat-perlite. Wetting and drying cycles could affect the growth media through several processes such as decomposition of organic compounds, displacement and rearrangement of particles, fragmentation of particles, shrinkage, hardening and subsidence. The growth media with a high percent of organic substrates were unstable as compared with those containing a high proportion of inorganic substrates. In general, the wetting and drying cycles increased the frequency of micropores in the growth media. The wetting and drying cycles positively affected EAW, WHC, AIR and WBC of most growth media. These findings imply that wetting and drying cycles may improve the growth media according to the studied extensive variables. However, it is necessary to study the intensive variables such as hydraulic conductivity, oxygen diffusion and pore tortuosity in the growth media for better evaluation of the impact of wetting and drying cycles as well. [ABSTRACT FROM AUTHOR]

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In this experiment, the influence of coal gangue as the admixture on the performance of dry-mixed mortar was studied, and the results were analyzed by XRD and SEM. The effects of different ways of crushing, particle size distribution, coal gangue, cement, admixture, and water content on the water retention, consistency, and 7 d compressive strength of dry-mixed mortar were investigated. The results show that the optimum content of hammer crushing of coal gangue through 3 mm sieve and cement is 83% and 17% of the total mass (W/W), respectively, the admixture content of 1# compound is 0.2 g/kg, and the amount of water is in the range of 194~200 mL/kg. At this time, the consistency can reach 91.5 mm, the water retention rate can reach 92.11%, and the 7 d compressive strength can reach 10.6 MPa, which meets the requirements of dry-mixed mortar for ordinary plastering and masonry mortar (GB-T 25181-2019). [ABSTRACT FROM AUTHOR]

This paper reports the study of potential water retention mechanisms based on the migration process of water molecules in the lunar regolith. First, we propose innovative definitions for the adsorption barrier coefficient, the collision barrier coefficient, and the total barrier coefficient for water molecule migration in the lunar regolith. Second, we derive an equation that relates the different barrier coefficients. Finally, we develop an equation for the diffusion coefficient of water in the regolith. The results are as follows. The collision barrier coefficient is a function of the soil layer porosity and pore number density and increases with increasing pore number density and decreasing porosity. The adsorption barrier coefficient depends on the soil temperature, adsorption heat, porosity, and pore number density and decreases sharply with increasing temperature. The adsorptive capacity of lunar soil to adsorb water molecules increases with increasing the adsorption barrier coefficient. For soil layers with a lower temperature, adsorption plays a more important role than collision in hindering the migration of H2O ${\mathrm{H}}_{2}\mathrm{O}$ molecules in the regolith. The total barrier coefficient increases with decreasing temperature, increasing adsorption heat, decreasing porosity, and increasing pore number density. Our results suggest that the water loss rate is inversely proportional to the total barrier coefficient. The water loss rate decreases with decreasing soil temperature, increasing adsorption heat, decreasing porosity, and increasing pore number density. Namely, water is more likely to be retained in areas where the regolith has a low temperature, large adsorption heat, and both low porosity and large pore number density. Plain Language Summary: Past experience has suggested that water is not present on the Moon. However, increasing evidence has shown that water is present in the regolith of permanent low‐temperature regions on the Moon. Our research aims to understand why water remains in the regolith. This paper develops a model to calculate how the lunar regolith hinders water migration. We derive an equation for the barrier coefficient of the water migration process in lunar regolith under various conditions. The adsorption effect can potentially impede the loss of H2O ${\mathrm{H}}_{2}\mathrm{O}$ molecules in the lunar regolith. The potential water retention area may extend to some regions covered by the regolith with large adsorption heat compared with the results of previous research. The area covered by the regolith with both great adsorption heat and low temperatures is most likely to retain water ice. Key Points: The collision effect and the adsorption effect influence the migration of water molecules in the lunar regolithEquations for barrier coefficients and the effects of different soil properties on water diffusion are establishedThe adsorption barrier coefficient may explain the presence of buried water ice if it is retained in the regolith [ABSTRACT FROM AUTHOR]

Numerous important earthen heritage sites in northwestern China have survived until today because of the arid and semi-arid climate. However, most of them suffer from various types and degrees of deterioration, with many questions not answered. Scaling off is one of the main types of deterioration widely observed at the Site of Yar City. To clarify the underlying mechanisms of cracked surface crust formation, previous experimental achievements are reviewed in the framework of unsaturated soil mechanics in this paper. A series of laboratory tests on the properties of local soil during desiccation, including water retention, volumetric shrinkage, cracking and tensile strength, are presented and analyzed, with a particular emphasis on salinity effect. Results show that suction is the key factor controlling the soil behavior. With the decrease in water content, all suction components increased gradually. The presence of NaCl led to a large increase in total suction, but a negligible change in matric suction. The soil shrinkage characteristic curve, which can be divided into three zones, was not affected by NaCl. The suction-loading curve indicates that the change in void ratio was governed by matric suction. In addition, most of the drying shrinkage of soil took place in saturated and near-saturated conditions. According to the quantitative analysis of final crack patterns, the highly fragmented surface morphology tended to be induced in thinner, less salinized soil specimens. The soil tensile strength also increased during drying, which was further enhanced by the cementation of salt crystals between particles. These preliminary results can provide some insights in understanding the on-site deterioration of earthen heritage sites. [ABSTRACT FROM AUTHOR]

Over a period of 30 years, the surface water level in the north-west of Konin, in the east of the Wielkopolska region, decreased by almost 6 m, resulting in a reduction of the surface area of the majority of nearby lakes, the disappearance of smaller water bodies and wetlands, and the drying out of streams draining the area. The causes of the decrease in the surface and groundwater level in the region are complex. They include both natural and anthropogenic factors, among others broad-scale mining activity. Based on knowledge of the hydrostructural composition of the analysed region and the functioning drainage system of opencast lignite mines, a concept was developed of a change in water supply to the flooded opencast lignite mine, Kazimierz Północ. The task of redirecting waters from the drainage of a nearby opencast mine, Jóźwin IIB, was implemented in 2020. Current observations and forecasts suggest that, owing to the applied solutions, the analysed opencast mine will be flooded in 2023, and not, as previously assumed, at the end of 2021. As a result, groundwater levels in the vicinity of the opencast mine as well as in lakes and rivers within the range of impact of the related depression cone will be restored faster, particularly in the Lake Powidzkie catchment. The objective of the study is to present stages of flooding of the former opencast lignite mine Kazimierz Północ, identify factors determining the process, and describe solutions accelerating it, with a simultaneous environmental impact assessment of the undertaken activities. [ABSTRACT FROM AUTHOR]

Using an efficient cost-benefit analysis framework and optimization model is essential for the proper planning of hydropower projects. The implementation of hydropower has different effects on the environment, which undermine the delivery of ecosystem services. The change in ecosystem services is often not included in hydropower projects' economic analysis and planning. Understanding the quantity of ecosystem services and their associated economic value is an important step to protection of ecosystems and provides an opportunity to enter ecosystem services into economic relations. Thus, the main purpose of this study is to investigate how to incorporate ecosystem services into project optimization models and decision-making. So, an attempt is made to quantify these environmental effects to develop a comprehensive simulation-optimization model and achieve a more sustainable development of hydropower projects in the system. The costs and benefits from the environmental economy include hydropower advantages and loss of ecosystem services added to the objective function. The results show that considering the environmental affects the NPV and decision variables such as the normal water level and installed capacity. The economic value of negative environmental impacts was more than its advantages and caused about 27% and 14.5% decrease in NPV and energy generation of the HPP project. [ABSTRACT FROM AUTHOR]

Alternate precipitation and evaporation often cause desiccation cracks in clayey soils, which necessarily change the soil water retention capacity. This work aimed to examine the influence of wet-dry cycles on the water retention behavior of compacted lateritic soil and further model the soil water characteristic curve (SWCC) of the soil containing cracks. Different wet-dry cycles were imposed on compacted lateritic soil specimens to produce desiccation cracks. Microscopic tests were performed to reveal the microstructural change of the soil. The SWCCs of the specimens after various wet-dry cycles were then measured and analyzed. The early six wet-dry cycles contribute most to the development of desiccation cracks. At microscale, some soil aggregates are broken into individual clay particles and further lost during wet-dry cycles, producing numerous microcracks and mesopores, which accounts for desiccation crack development. The SWCC of compacted lateritic soil changes from a unimodal form to a bimodal form under wet-dry cycles because of crack occurrences. With increasing cycle number, the first air entry value decreases and the reduction in volumetric water content becomes more evident, leading to a weaker water retention capacity of the soil. An empirical equation of the bimodal SWCC was proposed by incorporating a sigmoid function into the van Genuchten model and then verified with the experimental data. This equation can provide continuous and smooth bimodal SWCCs with all parameters having clear physical meanings. [ABSTRACT FROM AUTHOR]

Horizontal drilling and multi-stage hydraulic fracturing are the two key technologies for the successful development of shale gas reservoirs. However, there exist large uncertainties in optimizing hydraulic fracturing which affects water retention into shale matrix and gas productivity. In this work, a basic reservoir model with six-stage hydraulic-fracturing treatment was constructed to understand water retention and gas production in shale gas reservoirs. Gas diffusion, gas desorption, Darcy flow as well as non-Darcy flow were considered in this model. Then, a sensitivity study was performed to investigate the effects of hydraulic fractures on water retention and gas conductivity. The results indicate that only 34% of the fracturing water could be recovered back to the surface, and most of them remain in shale formations to interfere with gas production. The increase of fracture half-length, fracture width, fracture permeability, and fracture conductivity will reduce water retention while water retention in shale matrix will increase with the increasing of fracture spacing and fracture number. This work can provide a better understanding of the effects of hydraulic fractures on gas and water flow so as to optimize the hydraulic-fracturing treatment in shale gas reservoirs. [ABSTRACT FROM AUTHOR]

In arid areas, the rapid evaporation of water leads to severe water shortage for plant growth. Superabsorbent polymers have the prospect of preventing water evaporation because of its excellent water absorbency. However, insufficient in salt resistance, water retention, and swelling rate limit its application. Herein, we fabricated Hydroxyethyl cellulose-g-(Acrylic acid-co-2-Acrylamido-2-methyl-1-propane sulfonic acid)/laterite (HEC-g-P (AA-co-AMPS)/laterite) with exceptional abovementioned performances by aqueous solution polymerization. Under optimal synthesis conditions, the water absorbency of the superabsorbent polymer were 1294 g/g, 177 g/g, and 119 g/g in distilled water, tap water, and 0.9 wt% NaCl solution, respectively. The water retention of the superabsorbent polymer was still as high as 97.7% after 16 h at 25 ℃, the water absorbency was up to 832 g/g after re-swelling for 5 times at 40 ℃, and the water absorption reached swelling equilibrium was only 5 min. We investigated the effect of the mount of swollen hydrogel on the water evaporation rate in soil, and the results showed that hydrogels were effective in inhibiting soil water evaporation. Our study provides a new horizon for the application of superabsorbent polymer. [ABSTRACT FROM AUTHOR]

Primary quasi-solid Al-air batteries using hydrogels have attracted increasing research attention owing to their high energy density, good handling, safety and reliability. However, it is still difficult to develop hydrogel electrolytes with high ionic conductivity and water retention owing to limited capacity of single material hydrogels. Herein, we report a hydrogel electrolyte of poly (acrylic acid) (PAA) is modified by κ-carrageenan (KC) for solid-state Al-air batteries. The result suggests that the hydrogels not only exhibit outstanding water retention but also high ionic conductivity, which is attributed to the amorphous phase and hydrophilic group of the KC. Additionally, the lifespan of solid-state Al-air battery is extended at a current density of 5 mA cm−2 owing to adding KC. Further, the lifetime of open Al-air batteries is improved by self-corrosion inhibition of Al anode. [ABSTRACT FROM AUTHOR]

Nitrogen use efficiency enhancement is an important approach to obtain sustainable agriculture. Engineered biochar is considered as a super carrier to produce high-quality slow-release fertilizer. The purpose of this study was to compare nitrate and ammonium release using three treatments (i.e., MgCl2-modified biochar-based slow-release fertilizer (MBSRF), enriched modified biochar (EMBC), and chemical fertilizer (ammonium nitrate: AN)) and to analyze their effects on water retention, nitrogen use efficiency, and Zea mays L. growth. The treatments were prepared, and nitrate and ammonium release were determined. A pot experiment was performed with four treatments (control, MBSRF, EMBC, and AN), and the treatments' impacts on selected parameters were investigated. Soils treated with EMBC and MBSRF retained more water than those treated with AN and the control treatment. The nitrate and ammonium release of MBSRF was slower and about 2.5 and 1.5 times lower than that of AN. MBSRF effectively increased plant height (20.1, 11.7, 37.1 %), shoot dry weight (24.2, 23.3, 44.0 %), root dry weight (29.9, 24.1, 48.8 %), chlorophyll content (9.43, 8.01, 13.6 %), and leaf area (24.8, 21.0, 30.4 %) in comparison to the AN, EMBC, and control treatments, respectively. Furthermore, the highest soil and plant nitrogen content and nitrogen use efficiency were associated with the MBSRF treatment. In conclusion, the use of MgCl2-modified biochar is promising in the synthesis of nitrogen slow-release fertilizer, and MBSRF can be used as a novel nitrogen slow-release fertilizer for increasing nitrogen use efficiency and improving corn growth. [ABSTRACT FROM AUTHOR]

The superabsorbent polymers (SAP) possessed the favorable properties of absorbing and holding water, as well as the good degradability are urgently required for modern agriculture. And the grafting polymerization based on the natural polymers is an effective method for preparation of the SAP with degradability. In this work, a novel degradable SAP of CTS-g-PAA/SC was successful prepared via grafting the acrylic acid onto the chitosan (CTS) and introducing the oil shale semi-coke (SC) as inorganic component. The structure, morphology and thermal stability of the SAP were systemically studied by FTIR, SEM and TGA. Meanwhile, the water absorption capacities of SAP in different pH or various saline solutions as well as the reusability and the water retention capacity in soil were also investigated. The result suggested that the successful grafting polymerization and the SAP possessed the excellent water absorption capabilities, which were as high as 514.5 g/g in distilled water and 60.3 g/g in 0.9 wt% NaCl solution, respectively. More importantly, the cultivation experiments verified the SAP not only promoted the plants growth, but also could be degraded about 37.5% in the 70 days. Therefore, based on its excellent water retention, degradability and low cost, the SAP may have the great application potential in modern agriculture. [ABSTRACT FROM AUTHOR]

This study came into consideration following reported cases of women and girls using unhygienic materials such as old towels to keep themselves dry during their menses. The materials can be improved in quality and usability. The polymer that replaced wood pulp is not environmentally friendly. Water hyacinth and maize stalks have proven high absorbency properties, which are from ancient and current research. The objective was to optimize the hydroscopic properties of maize stalk and water hyacinth pulp and subsequent use in the design of sanitary pad. The methodology was done according to the standard KS 507:2005. The process of extraction was done using the alkaline method, and rinsing was done to remove excess NaOH. The pulp was studied for hydroscopic properties that included the retention capacity, absorbency rate and moisture content followed by the design of the sanitary pad. The absorbency rate and the retention capacity of maize are 50% and 150 s, respectively. The absorbency properties of maize internal tissue pulp are high, and it is feasibly viable. The retention and moisture content indicate over 50% and 57%, respectively. Water hyacinth pulp has a high absorbency rate (106 s). Also, the water retention and moisture content of water hyacinth pulp is over 50% and 59%, respectively. Upon blending, the water retained and held, and absorption rate improved to 50% in 24 h, 50% (25 ml) and 2 min. The significance levels for absorbency were 15 ml to 40 ml per minute and it holds and retains up to 500 times its weight. [ABSTRACT FROM AUTHOR]

Cover crops (CCs) can improve soil hydraulic properties prior to termination, but their effects on soil hydraulic properties during the growing season are less known. The objective of this study was to investigate the influence of no‐till CC on the soil hydraulic properties during the commodity crop growing season in Murfreesboro, USA. The CCs included hairy vetch (Vicia villosa Roth.), crimson clover (Trifolium incarnatum L.), winter wheat (Triticum aestivum L.), winter peas (Lathyrus hirsutus L.), oats (Avena sativa), triticale (Triticale hexaploide Lart.), barley (Hordeum vulgare L.) and flax (Linum usitatissimum L.). The cash crop grown was corn (Zea mays). Soil samples were collected using a cylindrical core (55 mm inside diameter, 60 mm long) at 0–10, 10–20, and 20–30 cm depths during April (prior to CC termination), May, June and July. Results showed that soil bulk density (Db) was 23%, 12%, 11% and 10% higher under no cover crop (NCC) compared with CC management during April – July, respectively. This suggests a lower rate of soil consolidation under CC management even after several rainfall events. Four months after CC termination, macroporosity and total porosity were 306 and 50% higher, respectively, under CC compared with NCC management. Therefore, saturated hydraulic conductivity (Ksat) during July was two times higher under CC management compared with NCC management and this can affect increase water infiltration and conservation during the growing season. Due to CC root‐induced improvement in macroporosity, CCs had 64% higher volumetric water content (θ) at saturation during July compared with NCC management. Cover crops can improve soil hydraulic properties and these benefits can persist for up to four months after termination. [ABSTRACT FROM AUTHOR]

Many activities are conducted with the view of reducing CO2 emission from fossil fuels, but mining extraction will continue to be important for energy sources, mineral and metal ores, and the general economy. This activity has negative environmental consequences such as habitat loss, water scarcity, and soil degradation in novel ecosystems. Additionally, climate change, drought, and desertification accelerate important problems with water retention. From one point of view, identifying and conserving critical regions for ecological sustainability are issues of fundamental importance, but on the other hand, post-mine sites could provide additional carbon sinks and improve regional water retention (WR). This review paper analyses different studies focusing on the impact of the reclamation of mining sites on the water retention properties of soil. Water retention in reclaimed mining soil (RMS) increased considerably after various restoration efforts were implemented. The amount of water holding capacity in RMS was mostly affected by reclamation methods, soil properties, soil biota, restoration duration, and vegetation type. The major conclusions from the analysis were that (i) the bulk density of reclaimed mining soil ranges from 1.35 to 1.50 g/cm3 and decreases with restoration duration; (ii) Soil fauna increases soil water storage capacity and plant litter and earthworms convert litter to fecal pellets, which increases water field capacity; and (iii) water holding capacity increases with duration of reclaimed sites and type of plants, i.e., afforestation and tree communities have higher WR than younger grasslands. Therefore, identification of the suitable reclamation method, restoration duration, vegetation type, and soil fauna are important factors for increasing water retention capacity at a regional scale. [ABSTRACT FROM AUTHOR]

Purpose: The increased human activities have significantly promoted the acidification of cultivated soils decreasing the soil water retention properties. This study investigated the improvement effect and mechanism of biochar on water retention properties of acidic soils. Materials and methods: Biochar was mixed with acidified and molded soils in different amounts (0, 2, 5, 8, and 10%), and then soil hydrological and water infiltration characteristics were analyzed. Results and discussion: The soil application of biochar, improved acidified soil capacity and porosity, and the effects were directly proportional to the applied amount of biochar. Compared to the control group, the application of 10%, biochar improved the average soil water content by 2.1–2.2 times and reduced the soil vertical infiltration rate by 41–43%. The soil vertical infiltration was 23–25% of that in the control group. Moreover, biochar-mediated improvement of soil aggregate agglomerates was found to be associated with the adsorption of soil microaggregates and the formation of water-stable macroaggregates. Conclusion: This study found that applying biochar to acidified soils can relieve the problems of poor water retention with a clear improvement mechanism. Large-scale soil application of biochar preventing migration of soil ions can contribute to environmental protection and natural resources recycling. [ABSTRACT FROM AUTHOR]

The cellulose-based hydrogel has been widely applied for soil water retention and nutrient release agents for several decades. Embedding the inorganic materials into hydrogels is an excellent strategy to improve the inherent limits of the cellulose-based hydrogel. Notably, municipal sludge-derived hydrochar (HC) has reduced the environmental burden and offered a potential hydrogel carrier to control water-retention and nutrient-release. However, the above function for plant growth of hydrochar-embedded carboxymethyl cellulose-g-poly(acrylic acid) (CMC-g-PAA/HC) is unknown, and relevant reports are lacking. This study investigated the water retention, nutrient release behavior, and effect of germination and plant growth of CMC-g-PAA/HC hydrogel. Characterization results showed that HC was successfully incorporated into CMC-g-PAA/HC with 6.0% higher thermostability, 7.2–21.0% lower swelling ratio (SR) in water, and substantial SR in phosphate solution (P-solution). The water loss rate of CMC-g-PAA/HC in P-solution or water owned a more significant temperature response (7.9–15.0 folds) than CMC-g-PAA (8.2–10.0 folds). Moreover, 4.0% higher n value and more 18.5% released P for CMC-g-PAA/HC were also observed. These phenomena were due to restricting the polymer chains movement and the water molecules diffusion inside the hydrogels with HC. Phytotoxicity assessments showed that HC in CMC-g-PAA/HC could effectively alleviate the inhibition effects on rape germination retained with 78.3% germination vigor and 80.0% germination ratio, even dramatically improved plant growth to 28 d. The results of this study demonstrated a new route for developing eco-friendly CMC-g-PAA/HC hydrogel, advantageous as a water retention agent and nutrient carrier in arid and semiarid regions.

An assessment of evaporation losses from soils is critical for sustainable agriculture in semi-arid regions. The purpose of this research was to determine the effect of desaturation and shrinkage on evaporative flux from representative soils. Results indicated that the surface area did not change for silty sand (6% volume reduction) and substantially increased for lean clay (17% volume reduction). The evaporative flux for silty sand decreased from 31 to 25 mg/m2∙s in Stage II, remained constant during Stage III, and decreased to 11 mg/m2∙s in Stage IV. In contrast, the lean clay showed a longer Stage II (34 to 14 mg/m2∙s), a near constant Stage III, albeit a similar Stage IV (13 to 3 mg/m2∙s). The air entry and residual suction values were 1 kPa and 100 kPa for silty sand and 5 kPa and 1400 kPa for lean clay. In both soils, the total suction merged with the matric suction at Stage II–Stage III boundary. Furthermore, the shrinkage curve was J-shaped for silty sand with the only void ratio decrease in Stage II, whereas that for the lean clay showed a significant void ratio decrease in Stage II, marginal decrease in Stage III, and no decrease in Stage IV. Under high demand, the silty sand exhibited Stage III and Stage IV evaporation, whereas the lean clay also showed significant flux during Stage II. For the investigated range of water content, the total water loss under high demand was found to be 7 times that under low demand.

Abstract Given the high precipitation verified in the Azores, peatlands, as water retention structures, are promoters of landscape balance, reducing the frequency of major events such as landslides. However, these ecosystems face increased land-use change disturbances that are placing the future security of these critical ecosystem services in doubt. This study aims to estimate the current and potential hydrologic services, particularly, water storage and water efflux, provided by the peatlands of Flores and Terceira Islands. Peatlands were initially identified through the distribution of Sphagnum, obtained by a spectral signature from satellite image analysis (Sentinel 2, Rapideye), completed with photointerpretation and historical data. The results show actual distributions of natural peatlands of 2766 and 2414 ha, for Terceira and Flores, respectively, which are relatively lower than the potential area estimated as 8035 and 5231 ha, correspondingly (20 and 37% of the total island area). Nowadays, these peatlands can retain 412,280,135 m3 of water. The higher altitude and more pristine areas represent the largest hydrological reservoirs and natural sources of water services. Theoretically, if all peatlands were natural, this capacity would increase to 300% of the retained water. These differences are most strongly reflected in peatland areas that are currently degraded or replaced by anthropogenic vegetation. Natural peatlands also showed greater capacity to restraint gravitational water, working as accumulation structures. Enhancing the naturalness of these areas would increase these ecosystems’ ability to act better as a buffer in extreme climate events. Article Highlights Actual distribution of natural peatlands is 2766 and 2414 ha, for Terceira and Flores, quite lower than the potential area. Currently retain 412,280,135 m3 of water, but this value could increase to 300% with adequate management and restoration, considering peatlands' potential area. This study follows the goals of the United Nations Sustainable Development as well as the 2030 Agenda in terms of climate change mitigation. Enhancing the naturalness would increase these ecosystems’ ability to act better as a buffer in extreme climate events. Restoration of peatlands would increase natural responses to expected climate change, protecting landscape equilibrium and population safety.

Natural polymer-based hydrogels are preferred as soil water retention agents due to their inherent biocompatibility and biodegradability. Generally, these natural polymers are chemically modified by graft polymerization of vinyl monomers to improve their water absorption and retention properties. Among the polysaccharides used to prepare natural hydrogels, those based on sodium alginate (Alg) stand out for their high-water absorption and retention capacity, as well as for their ability to promote plant growth. The main objective of this study was to develop a biodegradable alginate-based hydrogel as a water retainer to promote plant growth under water deficit conditions. The synthesis was achieved by grafting poly(acrylamide) (PAM) onto Alg backbone, using bisacrylamide as chemical crosslinker and different ratios of alginate:acrylamide (Ac). In addition, Eucalyptus nitens seedlings were used as a model plant to evaluate the effect of alginate-g-polyacrylamide (Alg:PAM) hydrogel application to the growing medium on plant survival, growth, and physiological responses under both well-watered and water-deficient soil conditions. The maximum degree of swelling (65 g/g) was obtained for the hydrogel prepared. The pseudo-second order model described the water uptake kinetics of the hydrogel. The degradability of Alg:PAM hydrogel reached up to 85 % in 5 weeks in soil and occurs by breaking the glycosidic bonds of the alginate. The E. nitens seedlings cultivated with different doses of Alg:PAM hydrogel (4:1 Alg:Ac) showed higher values of height and root diameter relative growth, survival and photosynthetic responses in comparison to non-treated plants. The results indicate that Alg:PAM hydrogel (4:1 Alg:Ac) has promising applications in forestry as a water retention and seedling growth promoter under water deficient conditions. [Display omitted] • Alginate/polyacrylamide hydrogel 4:1 ratio showed the highest water absorption and retention. • Morphology, water absorption and retention depended on alginate/acrylamide ratio. • Treatment of Eucalyptus nitens seedlings with this hydrogel favored growth and biomass accumulation. • Hydrogel had a positive effect on foliage maintenance under water stress. • The hydrogel shows potential for reducing mortality in young plantations established in drought-prone areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel organic–inorganic composite hydrogel (MxTy-CH) was fabricated. • The MxTy-CH retarded soil water evaporation and improved the soil properties. • Excellent heavy metal adsorption and fertilizer slow release performances of MxTy-CH were achieved. • The composite hydrogel impacted microbial communities and soil carbon and nitrogen cycles. Traditional hydrogel applied in soil tends to be unacceptable due to the high cost of synthesis raw materials and difficulty in degradation. To enhance water holding, adsorption of heavy metals and substrate fertility, this work developed a novel composite hydrogel (MxTy-CH) prepared from mandarin orange peel (MOP) and tobermorite (TOB). By arranging the enhancement of MOP and TOB, the water absorbency (from 171.23 g/g to 204.29 g/g), water holding (66.77 %, 144 h), adsorption characteristics (Cd2+ 339.93 mg/g; Pb2+ 1743.44 mg/g) and fertilizer slow-release performance (0.938 % released in 6 days) were significantly enhanced. The results indicated that the addition of MOP and TOB contributed to an enrichment in the number of –COOH and –OH groups contained in the system. Additionally, the adsorption behavior of cadmium/lead on MxTy-CH was more consistent with the pseudo-second-order kinetics and Langmuir isotherm models. The regeneration test results suggested that the adsorption removal rate of cadmium/lead by MxTy-CH remained stable after 5 cycles. Fish toxicity tests indicated that MxTy-CH was biocompatible and would not cause obvious physiological toxicity to fish organisms. The MxTy-CH treatment group performed better than control group in Cd(II) and Pb(II) passivation performance in soil with mung beans. Changes in the microbial community composition and structure after MxTy-CH treatment in soil provided demonstration for stimulated C and N cycling in soil, suggestive of enhanced soil quality. The abovementioned further proves the considerable application potential of MxTy-CH in plant growth and rehabilitation of cadmium and lead contaminated soil. [ABSTRACT FROM AUTHOR]

Hydrogels (HGs) are hydrophilic 3D-cross-linked polymers applied, inter alia, to improve soil resistance to drought. Their combination with biochar (BC), a product of biomass pyrolysis, can result in obtaining specific composites characterized by the advantages of both initial materials. The BC introduction into HG can double its swelling degree and increase their sorption capacity by more than threefold compared to the pure HG. Furthermore, the composites are able to increase plants biomass (up to 160%), even under heavy metal contamination, and are characterized by lower nutrient release rate (up to 25%) in comparison to the pure hydrogels. This review explores the properties of biochar-filled hydrogel composites, including swelling degrees and ability to absorb heavy metals and other toxic compounds. Additionally, it discusses their agricultural applications as soil conditioners and slow-release fertilizers, covering their effects on water and nutrient retention in the soil, soil microbial activity, as well as plant performance under contamination and drought stress. Finally, the cost-economic assessment and future prospects of these novel materials were proposed. The BC-filled HGs were considered as highly promising soil amendments, but their application potential depended entirely on the development of new production technologies and the investigation of interactions occurring between the composites and the selected soil components. • Biochar-filled hydrogel composites are highly promising soil conditioners. • Appropriate designing ensures multifunctionality of the materials. • They can act as slow-release fertilizers and water-holding agents. • Filler increases sorption capacity and detoxifying potential of the materials. • There is no studies on their mechanical properties and long-term field effects. [ABSTRACT FROM AUTHOR]

An affordable, eco-friendly, and salt-tolerant superabsorbent polymer (SAP) has been synthesised from Artemisia sphaerocephala Krasch gum (ASKG), a naturally hydrophilic heteropolysaccharide extracted from the seeds of Artemisia sphaerocephala and acrylic acid (AA) through free-radical polymerisation (ASKG/AA-SAP) using ammonium persulfate (APS) as the initiator and N, N´-methylenebisacrylamide (MBA) as the cross-linker. Morphological and thermal analyses confirmed that ASKG/AA-SAP showed a uniformly interconnected porous structure with a high thermal stability and a gradual decomposition rate. Notably, ASKG/AA-SAP demonstrated exceptional water absorbency, reaching maximum values of 1250 g·g−1 in distilled water and 152 g·g−1 in a 0.9 wt% NaCl solution. Work on relevant parameters related to SAP, viz water absorbency, water retention, and reusability under different influencing factors has been carried out, as also the swelling capacity, salt tolerance, and the ability to withstand a wide range of pH values (4−12) and temperatures (5–55 °C). Furthermore, ASKG/AA-SAP has also demonstrated water retention, viz maintaining a rate of 34.19 % after 5 h in distilled water, which are superior to those of other SAPs tested. Interestingly, the application of ASKG/AA-SAP has resulted in a substantial improvement in seed germination of desert plant, as evidenced by an increase in germination rate and germination energy of Hedysarum scoparium by 58.66 % and 35.71 %, respectively, compared to the control group. ASKG/AA-SAP, therefore, holds excellent potential for application in agri-forestry production and afforestation works within arid and semi-arid regions. [Display omitted] • An Artemisia Sphaerocephala Krash gum /acrylic acid-based novel eco-friendly SAP was successfully synthesized. • The ASKG/AA-SAP displayed an interconnected porous structure, excelling in water absorbency, retention, and reusability. • The ASKG/AA-SAP exhibited favorable thermal and chemical stability. • The ASKG/AA-SAP presented a significant improvement in the germination rate of seeds from desert plant species. [ABSTRACT FROM AUTHOR]

Ionic strength plays a significant role in the aggregation behavior of myofibrillar proteins. The study investigated the effects of KCl or CaCl 2 as substitutes for NaCl on the gel properties and taste of shrimp surimi at a constant ionic strength (IS = 0.51). Increased KCl substitution ratio resulted in a reduction in α-helix content and an increase in β-sheet content of myofibrillar proteins, thereby enhancing water holding capacity. Optimal KCl substitutions (1.5% NaCl +1.94% KCl) contributed to maintaining the desired taste and improving gel properties. CaCl 2 facilitates the extraction and dissolution of myofibrillar proteins, resulting in an organized and dense gel network with significant water-holding capacity. However, excessive additions (>1.27%) resulted in a notable decrease in taste and gel strength due to excessive aggregation and precipitation of myofibrillar proteins. These findings provide a solid theoretical foundation for production of high-quality, low-salt shrimp surimi. • The effect metal salt substitution was evaluated based on the same ionic strength • KCl induced a transition from α-helix to β-sheet to form a stable structure • Optimal KCl substitution maintains taste and improves gel properties • Proper CaCl 2 concentrations enhanced shrimp surimi gel texture and water retention • Excessive replacement with CaCl 2 led to a coarse network in low-salt shrimp surimi [ABSTRACT FROM AUTHOR]

A novel hyaluronic acid/ Gleditsia sinensis galactomannan hydrogel was prepared using various alkyl glycidyl ethers as cross-linking agents. The morphological, physicochemical, and mechanical properties of the obtained hydrogels were comparatively investigated and discussed. The optimal hydrogel exhibited high storage modulus (210 P), loss modulus (27.8 P), and water retention properties (95 %). The diffusion rate constant of water molecules in freeze-dried hydrogels exhibited a positive correlation with water uptake/equilibrium swelling rate, and the water molecules exhibited a non-Fickian type diffusion mechanism. Hydrogels with high molecular weight (Mw) hyaluronic acid showed higher water retention properties than those with low-Mw hyaluronic acid (80 % water retention properties). The molecular docking simulations of hyaluronic acid confirmed the higher formation energies of the high-Mw hyaluronic acid (-14.98 Kcal/mol) than that of the low-Mw hyaluronic acid (-6.90 Kcal/mol). This study offers a new design strategy for a water retention hydrogel by optimizing the cross-linked dimension with various-length polymer chains as cross-linkers. These remarkable advantages make hydrogels have enormous potential in the application of cosmetics and biomedical. • A epoxy-crosslinked galactomannan hydrogel was prepared with hyaluronic acid. • Length of cross-linker determined the mechanical property. • Molecular weight of hyaluronic acid affect the water retention behavior of hydrogel. • Hydrogels exhibited excellent mechanical strength and biocompatibilities. [ABSTRACT FROM AUTHOR]

• A novel UIO-66@PDA/SAhydrogel composite bead soil conditioner with water retention and adsorption properties was developed. • The water retention experiment demonstrates that this hydrogel composite bead owns a good water retention performance. • Adsorption experiments showed that this hydrogel composite bead can effectively adsorbmethylene blue at pH=7 and T = 298.15 K. A hydrogel composite bead soil conditioner with water retention, adsorption and recyclability properties was developed. The core material of the beads was metal organic framework material UIO-66, while the shell material consisted of polydopamine (PDA) and sodium alginate (SA). Characterization techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) were used to analyze and demonstrate the structure and composition of the composites. The water retention experiment and soil water loss experiments showed that the UIO-66@PDA/SA hydrogel composite beads had a water retention rate of 10.96 % after 300 min and a water evaporation rate of less than 1 % in soil within 4 h, indicating good water retention performance. Adsorption experiments showed that the UIO-66@PDA/SA hydrogel composite beads effectively adsorbed methylene blue (MB) with an equilibrium adsorption amount of 213.79 mg/g. This was a 72.6 % increase compared to pure sodium alginate (SA). They had the highest adsorption capacity of 240.79 mg/g at pH=9 and T = 298.15 K, indicating that alkaline conditions favored the adsorption process. The adsorption process followed the Pesudo-second-order model and exhibited characteristics of the Langmuir adsorption isotherm model. In addition, dynamic adsorption analysis demonstrated that the UIO-66@PDA/SA hydrogel composite beads owned efficient recyclability, and the relative adsorption efficiency remained above 90 % after 4 cycles. This technology offers a cost-effective, uncomplicated, and efficient solution for promoting a healthy soil environment and facilitating agricultural applications. [ABSTRACT FROM AUTHOR]

The remediation of heavy metal-contaminated soils necessitated a holistic approach that encompassed water and fertilizer conservation alongside soil property restoration. This study introduced the synthesis of (poly)acrylamide-layered double hydroxide gel spheres (PAM-LDH beads), which were designed to simultaneously immobilize heavy metals, control the release of fertilizers, and enhance soil water retention. Laboratory soil experiments under diverse conditions highlighted the superior performance of PAM-LDH beads in the immobilization of hexavalent chromium (Cr(VI)). The layered double hydroxide (LDH) component was identified as the key player in Cr(VI) immobilization, with anion exchange being the predominant mechanism. Notably, the encapsulated urea within the beads was released independently of environmental influences, governed by a concentration gradient across the beads surface. This release process was characterized by an initial phase of absorptive swelling followed by a diffusive phase. The impact on plant growth was assessed, revealing that PAM-LDH beads significantly curtailed Cr(VI) accumulation and alleviated its phytotoxic effects. Changes in the carbon (C) and nitrogen (N) content of the plants suggested that the urea encapsulated within the beads served as a nutrient source, contributing to soil fertility. Moreover, the water-holding capacity and soil-water characteristic curves of PAM-LDH beads suggested that these superabsorbent beads could delay soil water evaporation. The observed shifts in microbial community structure provided evidence for the enhancement of soil carbon and nitrogen cycles, indicative of improved soil properties. [Display omitted] • (poly)acrylamide-layered double hydroxide beads significantly immobilized Cr(VI). • The release process of fertilizer is driven by concentration gradient. • The beads mitigated biotoxicity in plants, and increased in biomass of C and N. • The beads retarded soil water evaporation and improved the soil pore structure. • The beads impacted microbial communities and soil carbon and nitrogen cycles. [ABSTRACT FROM AUTHOR]