Increased Water Retention Research Articles

Drought potential index using Normalized Difference Drought Index (NDDI) method based on Geographical Information System (GIS) in Slogohimo, Wonogiri Indonesia

Climate change is an impact caused by global warming. The phenomenon due to climate change is El Nino, which affects a long dry season. Central Java is an area heavily affected by drought caused by El Nino, one of which is Wonogiri Regency, which has the potential to cause crop failures, forest fires, and decreased water availability, which can be detrimental. Drought potential analysis was carried out to estimate the distribution of the drought index in Slogohimo District, Wonogiri Regency. The method used is the Normalized Difference Drought Index (NDDI), which combines vegetation density and wetting level using Landsat imagery—the NDDI index transformation method on a scale ranging from very low to very high (severe). The results show that the distribution of drought potential in Slogohimo District, Wonogiri Regency, is classified as very low to very high class. Still, the broadest area is classified as low. The tendency for drought to occur in the Slogohimo area is spread from the east to the south. This research suggests the application of organic mulch for improvement to reduce the potential for drought. Apart from being an effort to modify soil temperature, organic mulch also functions as a soil conditioner, which impacts adding soil pores to increase water retention.

Experimental Design of High-Performing Open-Cathode Polymer Electrolyte Membrane Fuel Cells

Open-cathode polymer electrolyte membrane fuel cells (PEMFCs) utilize a unique air-cooled system design to eliminate the humidifiers, air compressor, and liquid cooling loop of conventional, liquid-cooled PEMFC systems, thereby greatly reducing system cost. However, the open-cathode PEMFC performance is restricted by poor humidification, high membrane and charge transfer resistances, and overheating due to inefficient thermal and water management. This work aims to strategically modify the membrane electrode assembly (MEA) design to overcome these issues and achieve high open-cathode PEMFC performance that approaches that of liquid-cooled systems. The use of thinner membrane along with short side chain ionomer is found to elevate the cell performance due to increased water retention at the cathode catalyst layer (CCL) and decreased ohmic losses. Thinner gas diffusion layers with high porosity enable additional cell performance increment by improving oxygen availability at the CCL. An overall current density rise of 88% at 0.6 V and 53% at 0.4 V is achieved by the strategically designed MEA for open-cathode cells. The enhanced power density enabled by the custom MEA can both reduce the stack cost and expand the power range of open-cathode PEMFCs, thus expanding their potential use for low-cost fuel cell system applications.

Oil Frying Processes and Alternative Flour Coatings: Physicochemical, Nutritional, and Sensory Parameters of Meat Products.

The frying process changes can be desirable and undesirable, involving the physicochemical, nutritional, and sensory aspects, depending on the food and oil properties and the frying process. In this context, alternative flours emerge as a strategy for adding value to the food since they are rich in fiber, vitamins, and minerals, contributing to the variability of ingredients and the full use of food, including residues such as seeds and husks. This narrative review aims to gather current scientific data addressing the alternative flour coatings on breaded meat, mainly chicken, products to evaluate the effects on fried products' nutritional value, physicochemical parameters, and sensory attributes. Scopus, Science Direct, Springer, and Web of Science search bases were used. This review showed that alternative flours (from cereals, legumes, fruits, and vegetables) used as coatings increase water retention and reduce oil absorption during frying, increase fibers and micronutrient content, which are not present in sufficient quantities in commonly used flours due to the refining process. These flours also reduce gluten consumption by sensitive individuals in addition to favoring the development of desirable sensory characteristics to attract consumers. Therefore, frying processes in oil promote a reduction in humidity, an increase in oil absorption and energy content, and a decrease in vitamin content. In this context, coatings based on alternative flours can reduce these adverse effects of the frying process.

Functionally responsive hydrogels with salt-alkali sensitivity effectively target soil amelioration

The long-standing crisis of soil salinization and alkalization poses a significant challenge to global agricultural development. High soil salinity-alkalinity, water dispersion, and nutrient loss present major hurdles to soil improvement. Novel environmentally friendly gels have demonstrated excellent water retention and slow-release capabilities in agricultural enhancement. However, their application for improving saline-alkali soil is both scarce and competitive. This study proposes a new strategy for regulating saline-alkali soil using gel-coated controlled-release soil modifiers (CWR-SRMs), where radical-polymerized gels are embedded on the surface of composite gel beads through spray coating. Characterization and performance analysis reveal that the three-dimensional spatial network structure rich in hydrophilic groups exhibits good thermal stability (first-stage weight loss temperature of 257.7 °C in thermogravimetric analysis) and encapsulation efficiency for fulvic acid‑potassium (FA-K), which can enhance soil quality in saline-alkali environments. The molecular chain relaxation under saline-alkali conditions promotes a synergistic effect of swelling and slow release, endowing it with qualifications as a water reservoir, Ca2+ source unit, and slow-release body. The results of a 6 weeks incubation experiment on 0–20 cm saline-alkaline soil with different application gradients showed that the gradient content had a significant effect on the soil improvement effect. Specifically, the T2 (the dosage accounted for 1 % of soil mass) treatment significantly increases water retention (30 % ~ 90 %), and nutrient levels (30 % ~ 50 %), while significantly decreasing soil sodium colloid content (30 % ~ 60 %) and soil pH (10 % ~ 15 %). Furthermore, PCA analysis indicates that the addition of 1 % CWR-SRMs as amendments can significantly adjust the negative aspects of soil salinity and alkalinity. This highlights the excellent applicability of CWR-SRMs in improving saline-alkali agricultural ecosystems, demonstrating the potential value of novel environmentally friendly gels as an alternative solution for soil challenges persistently affected by adverse salinity and alkalinity.

Improving crop growing conditions with water treatment residual and compost co-amendments: Soil-water dynamics.

Land application of water treatment residual (WTR) in combination with phosphate-rich organic wastes, like compost or sewage sludge, in nutrient-poor soils was previously shown to promote crop growth. This WTR diversion from landfill to agriculture supports local and international mandates for waste circularity. Although soil-water dynamics-like saturated hydraulic conductivity, water retention, and hydrophobicity-are well-defined for compost and somewhat defined for WTR (except for hydrophobicity), the impacts of co-amending sandy soils with both are not well-defined. In laboratory analyses, co-amendment had an intermediate effect between individual amendments on the hydrophobic sandy soils, increasing water retention by 27% (WTR and compost both increased water retention), decreasing hydrophobicity by increasing hydraulic conductivity twofold (WTR and compost both decreased hydrophobicity), and having no effect on saturated hydraulic conductivity (decreased by WTR and increased by compost). With two positive effects and one "no effect" on soil-water dynamics in laboratory trials, the co-amendment was expected to buffer both crop water use efficiency (WUE) and nutrient availability under drought stress, for Swiss chard (Beta vulgaris L. var. cicla), co-investigated in a multifactorial pot trial. Soil nutrients, particularly phosphate, were shown more critical than soil-water dynamics to improve crop WUE. Thus, co-amended soils have significantly higher crop biomass and WUE than sandy soils. Phosphate-rich organic co-amendment is necessary for crop nutrient sufficiency and thus drought resilience in sandy soils amended with WTR. Thus, pairing wastes to soils for optimum fertility is a critical consideration in waste land application for both biomass and drought resilience.

Adsorption mechanism of alkylphenol ethoxylates surfactants (APEO) on anthracite surface: A combined experimental, DFT and molecular dynamics study

The serious hazards posed by inhalable coal dust to the safety, air purity, and health of coal miners can be effectively alleviated through the use of appropriate dust suppressants. The wetting enhancement capabilities of two dust suppressants, octylphenol polyoxyethylene ether (OP-10) and nonylphenol polyoxyethylene ether (NP-10), were examined in this study through experimental and simulation methods. Macroscopic experiments (surface tension, contact angle, coal dust settling time, and water retention) indicate that the shorter the alkyl chain attached to the benzene ring in the surfactant and the lower the surface tension, the more conducive it is to improving the fluidity and suspension stability of anthracite particles in the wetting solution and further improving the interfacial properties and wetting effect between coal dust and the liquid medium. Mesoscopic experiments (laser particle size, FTIR, XPS, UV–visible spectroscopy, BET, and SEM) showed that the relevant properties of APEO-modified coals were greatly changed, especially the anthracite modified with short-chain alkyl groups of OP-10, which exhibited a stronger aggregation effect on the coal dust particles and increased the pore structure and specific surface area of the coal dust. Additionally, the hydrophilic functional groups are augmented, leading to a notable enhancement in the adsorption capacity of OP-10 on the coal surface. Microscopic simulations (Density Functional Theory calculations, Molecular Dynamics simulations) reveal that APEO surfactants with longer alkyl side chains attached to benzene rings hinder the π-π interactions between the coal's aromatic ring structures and the benzene rings in the surfactants. The surface polarity of coal modified with OP-10 is significantly enhanced, resulting in a more pronounced improvement in wetting performance and an increased water retention capability. The study systematically explores surfactant microstructure effects on anthracite wetting, laying essential groundwork for advanced dust suppression system development.

Using embossing ice particulate method to prepare polyvinyl alcohol/pullulan hydrogels with surface open pores loaded with microspheres for breast cancer treatment

In the post-operative treatment of breast cancer, early prevention of locoregional recurrence is crucial to avoid metastasis of cells from leftover microtumor tissues. The limitations in conventional drug delivery systems show a growing clinical demand for disease-specific drug-releasing systems. This study explores a novel poly(vinyl alcohol)/pullulan (PVA/PUL) hydrogel system for local drug delivery in post-operative breast cancer treatment. Hydrogel was produced by combination of lyophilization and embossing ice particulate techniques to create microspheres loaded open pores on the hydrogel surface for localized release of doxorubicin-loaded polycaprolactone microspheres (DOX-PCL-MSs). PVA/PUL hydrogel was successfully crosslinked with glutaraldehyde and stabilized hydrogel structure has possessed slow degradation rate and increasing water retention through 12 days. Release of DOX after 7 and 16 days from DOX-PCL-MSs loaded hydrogels were slower with a 6.2 ± 8.9 % and 56.6 ± 4.5 % release compared to 60.9 ± 14.6 % and 76.8 ± 19.7 % release from free DOX loaded hydrogel since DOX release was controlled by PCL microspheres. When interacted with human breast cancer cell line (MCF-7), DOX-PCL-MSs were able to disrupt cell and spheroid morphology after 7 days at concentrations as low as 12 μg/mL loaded DOX. In vitro cytotoxicity study has showed that, DOX-PCL-MSs loaded hydrogel was able to decrease MCF-7 viability after 7 days of incubation with controlled release of DOX. While free DOX releasing hydrogel has lost cytotoxic activity even after 4 days of incubation. Furthermore, ability of PVA/PUL hydrogel to support L929 cell attachment was shown in the study, suggesting hydrogels potential for promoting tissue regeneration after anti-cancer treatment. The study reveals that PVA/PUL hybrid hydrogels loaded with DOX-PCL-MSs has impactful potential in post-surgical treatment of breast cancer.

Retardation effect of the pozzolanic reaction of low-calcium supplementary cementitious materials on clinker hydration at later age: Effects of pore solution, foreign ions, and pH

Clinker hydration at later age in blended cement pastes was found to be retarded by the pozzolanic reaction of low-calcium supplementary cementitious materials (SCMs). Various mechanisms were explored, including the consumption of pore solution, the presence of foreign ions, and pH-related effects. Experimental results indicated that the dissolution of the foreign ions from SCMs was a secondary effect. The primary cause of the retardation effect was the reduction in pH caused by the pozzolanic reaction. Aqueous precipitation tests yielded the following findings related to pH: (1) At lower pH levels, the precipitation of aluminium-incorporated calcium silicate hydrate(C–A–S–H) gel was reduced due to the decreased nano-adhesion force. (2) The morphology of C–A–S–H gel consisted of small spherical particles at lower pH levels, resulting in a denser capillary pore structure. The latter led to increased water retention within the fine gel pores but a reduced amount of pore solution available in the capillary pores for cement hydration.

Mycorrhizal association and its relation with pteridophytes.

Mycorrhizal association is one of the earliest and diversely distributed symbiotic associations on the Earth. This association helped early terrestrial plants to colonize the land by improved supply of nutrients like phosphate, nitrogen and zinc. It also helped plants to tolerate unfavorable soil conditions with increased water retention capacity, resistance to drought and pathogens. In return, fungi benefitted with carbon as their food source from the plants. More than 80% of terrestrial plants including pteridophytes, gymnosperms and angiosperms are reported to form arbuscular mycorrhizal (AM) association. Plants with root systems appeared on land during the Devonian period and many of them like pteridophytes still exist today. Various molecular and fossil studies confirm that the plants belonging to Ordovician-Devonian are associated with fungi, which are very similar to genus Glomus. AM association is very common in pteridophytes and the growth of its sporophyte and gametophyte is directly affected in the presence of AM association. Pteridophytes as early land plants with root systems have a very significant place in the plant kingdom. They have evolved and adapted to fill various habitats and facilitated early terrestrialization of other land plants by providing suitable niche with the help of AM fungi. In spite of pteridophytes being a very important plant group in the land system, very few reports are available on fungal-pteridophyte association. The present review is an effort to gather information about AM association in pteridophytes that might help in unraveling the evolution and significance of plant and fungi association.

Retenção de água em solos arenosos de diferentes materiais de origem com adição de biocarvão

ABSTRACT This study evaluated biochar influence on water retention in sandy soils with different source materials. Samples from Horizon A of six profiles of Neossolos Quartzarênicos (Salto das Nuvens, Utiariti, Pantanal, Coberturas Detrito Lateríticas Ferruginosas, Botucatu e Bauru formations), collected in different regions of the state of Mato Grosso, Brazil, were used to determine the hydro-physical characteristics with the addition of biochar. The biochars assessed were produced from two sources of raw material (sugarcane filter cake and cotton husks) under pyrolysis at a temperature of 400 °C. Retention curves for soils with and without biochar, the field capacity, permanent wilting point, available water in the soil, total porosity, macroporosity, and microporosity were determined. The results evidenced that the application of biochar increases the microporosity (86.7% with cotton husks biochar and 67.9% with filter cake biochar) and reduces the microporosity of sandy soils (38.2% with cotton husks biochar and 36.0% with filter cake biochar); also, there was a higher increase in water availability with biochar from cotton husks (57.1%). There was an increase in soil microporosity and a reduction in macroporosity due to the influence of biochar addition in the sandy soils from the Salto das Nuvens, Utiariti, Pantanal e Coberturas Detrito Lateríticas ferruginosas, with no changes in the Botucatu and Bauru Formations. Biochar increases water retention in sandy soils; however, this does not occur for all geological formations studied.

The effect of lime leaf extract (Citrus aurantifolia) through drinking water on the chemical and physical quality of broiler meat

This study aims to investigate the impact of supplementing lime leaf extract (EDJ) in broiler chickens' drinking water on both the chemical and physical qualities of their meat. A total of 128 New Lohmann MB 202 strain broiler roosters were subjected to the same basal feed regimen but received distinct drinking water treatments over a 35-day rearing period. The drinking water treatments included plain water without additives (negative control; T0), water supplemented with 50 ppm Tetracycline antibiotics (positive control; T1), water enriched with 15 ml/liter EDJ (T2), and water infused with 30 ml/liter EDJ (T3). The basal diet consisted of corn and soybean flour, with a crude protein content of 22.01% and a metabolic energy level of 3113.12 kcal/kg. Feed and drinking water are provided ad libitum during the rearing period. The parameters observed in this study were the chemical and physical quality of the meat, which included variables: moisture content, ash content, protein content, fat content, pH value, water holding capacity, cooking loss, and tenderness. The data obtained were then analyzed for variance (ANOVA) using a one-way Complete Randomized Design based on a P value of less than 5%. The findings of the study indicated that the supplementation of EDJ through drinking water did not produce significant alterations in water content, protein content, fat content, cooking loss, or tenderness of the broiler meat. However, a notable outcome was observed: the addition of 30 ml/liter of EDJ to the drinking water led to a substantial increase in water holding capacity (P<0.05) while simultaneously reducing the meat's pH value (P<0.05). These results suggest that EDJ supplementation has the potential to enhance the physical quality of broiler meat, primarily by increasing water retention and decreasing pH values, which can contribute to improve meat texture and juiciness.

Renewable whey-based hydrogel with polysaccharides and polyvinyl alcohol as a soil amendment for sustainable agricultural application

This work describes the preparation of a novel biopolymer hydrogel based on acid whey, cellulose derivatives and polyvinyl alcohol (PVA). The hydrogel was prepared and characterized with the aim of producing an environmentally-friendly soil amendment to increase water retention capacity of the soil. The findings showed considerable swelling properties of the hydrogels depending on the PVA content and crosslinking density. The samples with PVA in a concentration 2.5 % and 5 % were more rigid, the gel fraction increased with a subsequently decrease in their swelling capacity. The hydrogels crosslinked with 15 % of citric acid demonstrated a constant swelling ratio (SR) of around 500 % within 10 swelling/drying cycles. The hydrogels crosslinked with 10 % citric acid and supplemented with 1 % of PVA showed SR of 1000–1400 % caused by less crosslinked polymer network and increased pore volume for water uptake. It was found that hydrogel with a higher gel fraction had a stable structure. Supplementing PVA at 5 % extended the period of decomposition of the hydrogel material by almost 60 % in the soil environment and soil humidity was maintained for longer. Applying 2 % of the hydrogel 5PVA to soil increased the water retention capacity by 19 %.

Changes in phytochemical properties and water use efficiency of peppermint (Mentha piperita L.) using superabsorbent polymer under drought stress

Water consumption management and the application of advanced techniques in the agricultural sector can significantly contribute to the efficient utilization of limited water resources. This can be achieved by improving soil texture, increasing water retention, reducing erosion, and enhancing seedling germination through the use of superabsorbent polymers. This study aimed to investigate the effect of Aquasource superabsorbent (AS) on the morphological characteristics, phytochemical properties, antioxidant content, and water use efficiency of peppermint. It was conducted under different irrigation management and using different superabsorbent levels. Therefore, a 3 × 4 factorial design was used to determine the effects of irrigation intervals (2-, 4-, and 6-day) and different levels of AS amount (zero [control], 0.5, 1, and 2 wt%). The effects of these factors on various parameters (morphological characteristics, essential oil percentage, nutrient, protein, proline, carotenoid, antioxidant, and chlorophyll content, leaf area index, relative water content, and water use efficiency [WUE]) were evaluated. The results showed that morphological characteristics and essential oil percentage decreased significantly under drought stress (increasing the irrigation intervals). However, the addition of 0.5 (wt%) AS improved plant growth conditions. Increasing the amount of superabsorbent used to 1 and 2 (wt%) decreased the measured traits, which indicates the creation of unsuitable conditions for plant growth. AS application improved the growth of the root more than the leaf yield of peppermint. A 0.5 (wt%) addition of AS resulted in root length increases of 3, 13, and 15%, respectively, at irrigation intervals of 2, 4, and 6 days, respectively. Additionally, at 0.5 (wt%) AS, root weight increased by 8, 15, and 16% in 2-, 4-, and 6-day irrigation intervals, respectively. Also, the height of the plant increased by 3, 5, and 17% at 2-, 4-, and 6-day irrigation intervals when 0.5 (wt%) of AS was used compared to the control. As well, essential oil percentage increased by 2.14, 2.06, and 1.63% at 2-, 4-, and 6-day irrigation intervals. The nutrient and protein contents decreased as irrigation intervals and AS usage increased, indicating a similar trend. However, compared with the control, the addition of 0.5 (wt%) of AS resulted in some improvements in nutrients and protein. The highest WUE (3.075 kg m−3) was attained in the 4-day irrigation interval and 1 wt% AS addition. This was followed closely by the 2-day irrigation interval with 1 wt% AS addition at 3.025 kg m−3, and the 4-day irrigation interval with 0.5 wt% AS addition, which reached 2.941 kg m−3. Overall, the use of AS in appropriate amounts (0.5 wt%) can reduce water consumption and enhance essential oil yield and WUE in peppermint cultivation in water-scarce arid and semi-arid regions.

Resveratrol-loaded decellularized ovine pericardium: ECM introduced for tissue engineering.

An ideal scaffold for skin tissue engineering should have a suitable potential for antibacterial activity, no hemolysis, sufficient porosity for air exchange, water retention capacity, and a suitable swelling rate to maintain tissue moisture. Considering this issue, our study used decellularized ovine pericardial tissue's extracellular matrix (ECM). These scaffolds were decellularized with sodium dodecyl sulfate (SDS) and sodium deoxycholate (SD) detergents along with vacuum methods. Following imaging with scanning electron microscopy (SEM), analysis of the mechanical properties, and the measurement of the amount of DNA, collagen, and glycosaminoglycan (GAG), our study observed that the three-dimensional (3D) structure of ECM was largely preserved. Resveratrol (RES) 400µg/µL was loaded into the above scaffold, and analysis revealed that scaffolds containing RES and with vacuum reported higher antibacterial properties, a higher swelling rate, and increased water retention capacity. The biocompatibility and hemocompatibility properties of the above scaffolds also reported a significant difference between methods of decellularization.

Enhancement of water absorption properties of date palm fibers-based composites via alkaline treatment

This study examined the ability of a biodegradable composite material to absorb water. The composites were created by combining a matrix of polylactic acid (PLA) with date palm wood fibers (DPWF) for reinforcement. Before incorporating the fibers into the polymer, they underwent chemical treatment using alkali solutions of NaOH and KOH. This treatment aimed to modify the surface properties of the natural fibers and enhance their water absorption capabilities. Different composites were fabricated, including PLA combined with untreated fibers (PLAUF), and PLA with treated fibers using both NaOH and KOH (PLAF-NaOH and PLAF-KOH), with varying weight percentages of fibers ranging from 0 to 40%. To evaluate the water absorption capability of the composites, water retention tests were conducted at room temperature (cold) and 50 °C (hot) for 24, 48 h and until the absorption reached equilibrium. The results demonstrated a significant enhancement in water retention, particularly in the case of the NaOH-treated samples, which exhibited approximately a tenfold increase in water retention compared to untreated samples. For example, the 20 wt% NaOH treated filler had a hot-water retention of 20%, compared to 2% for the untreated filler. Additionally, a higher percentage of filler resulted in a higher rate of water absorption. The 40 wt% NaOH treated sample with 20% water retention, absorbed 10 times more than the 10 wt% NaOH treated filler, with only 2% water retention. The developed composites have potential applications in natural gas dehydration processes, offering an alternative to the energy-intensive and environmentally harmful glycol-based dehydration methods currently in use.

3D bioprinted human neuron‐like spheroids as an in vitro model for neurodegenerative diseases

AbstractBackgroundThe limited number of reproducible in vitro models for neurobiology purposes consists of a difficult challenge, primarily because naturally, in the organism, cells are organized three‐dimensionally. The concept of developing three‐dimensional (3D) models to further elucidate brain organization, mechanisms, and pathways has the importance of reaching characteristic features of native tissue that facilitate the comprehension of complex neurodegenerative diseases, such as Alzheimer’s disease (AD). Bioprinting has revolutionized the concept of three‐dimensionality, producing complex structures and sculptural constructs. This study aims to demonstrate the first steps of a novel 3D bioprinted construct, illustrating that neuron‐like cells organize themselves as spheroids when cultured in a 3D environment.MethodFirst, the bioink was prepared by adding human neuroblastoma cells (SH‐SY5Y), differentiated into a more mature neuron‐like phenotype by the addition of 2% retinoic acid, for seven days into a hydrogel consisting of an Alginate/Gelatin solution. As control cells were cultured in the absence of retinoic acid. The constructs were bioprinted and crosslinked by the addition of 2% CaCl2. The swelling degree of printed hydrogel and morphological cytoskeletal organization of the neuron‐like spheroids were evaluated.ResultThe developed hydrogel has a high swellability, increasing water retention upon long‐term immersion (Figure 1A). Swellability is an important feature, indicating the hydrophilicity of the construct, which facilitates cell‐cell interactions and culture medium diffusion into the construct core. Importantly, when cellular organization within the construct was evaluated, we observed that the SH‐SY5Y cells arranged themselves as spheroids (Figure 1B), a valuable tool for investigating the 3D cellular organization. This feature reproduces important natural tissue characteristics, such as producing extracellular matrix components and forming a network of cell‐cell interaction, which cannot be reproduced in 2D structures. Moreover, neurite outgrowth is observed inside the spheroidal construct with differentiated cells (Figure 1B).ConclusionThe 3D bioprinted construct is highly suitable and advantageous as a neurobiological 3D model. Based on this construct, further studies are being developed to better simulate AD in vitro, building an interactive disease model. Acknowledgments: This study was supported by São Paulo Research Foundation (FAPESP, grants 2022/08664‐4 and 2018/45605‐8), and Brazilian National Council for Scientific and Technological Development (CNPq, grant 406258/2022‐8).

Bentonite Impact on Soil Properties and Biological Activity in the Face of Drought : A Review

The clay mineral bentonite has received a lot of attention for its potential to reduce the harmful effects of drought on soil health and biological activity. Reduced enzymatic activity and microbial diversity are two negative outcomes of the drought’s impact on soil quality. Bentonite, however, has been shown to aid in the restoration of biological functions in drought-affected soils. Bentonite’s function as a soil moisture retainer is an important consideration. Bentonite acts as a reservoir, trapping water within its layers due to its high water-holding capacity and ability to form a gel-like structure. This capacity for water retention can reduce the negative impact of drought on soil organisms, making conditions better for enzyme activity and microbial life. Bentonite has also been shown to increase soil enzyme production and activity. Soil fertility and healthy ecosystems rely on the work of enzymes in nutrient cycling and organic matter decomposition. Reduced enzymatic activity is a common consequence of drought stress, which in turn reduces nutrient availability and worsens soil health. The application of bentonite, however, has been shown to increase enzyme production and activity even in drought conditions. This has the potential to improve soil health and productivity by preserving vital soil processes and encouraging nutrient cycling. In addition, bentonite can increase soil microorganism activity in dry areas. Soil microorganisms play a crucial role in the cycling of nutrients, the control of disease, and the health of the soil ecosystem as a whole. Reduced microbial diversity and activity have been linked to drought stress. However, research shows that applying bentonite to drought-affected soils increases both microbial growth and diversity. Increased nutrient availability, enhanced soil structure, and enhanced water infiltration and retention are all possible results of microbial stimulation. In conclusion, areas that have experienced drought can benefit from bentonite’s ability to improve soil enzymes and biological activity. Bentonite helps restore and maintain soil health even when water supplies are low. It does this by increasing water retention, encouraging enzyme production, and boosting microbial activity. To fully realize bentonite’s potential for fostering sustainable agriculture and sustaining healthy ecosystems, more study is required to determine the optimum application rates and methods.

Degree of compaction, aeration, and soil water retention indices of a sugarcane field without soil disturbance after initial tillage

Soil compaction after initial soil tillage for crop establishment has been a major problem in crop fields because of its deleterious effects on soil functioning and crop performance. Therefore, the study aimed to determine the degree of compaction, soil air capacity, near-surface optimum ratios, and water retention characteristics in a sandy loam. Dystrophic Paleudalf initially under different tillage methods for sugarcane crop but without tillage for two seasons in southern Brazil. Initial soil tillage systems consisted of no-tillage (NT), compacted no-tillage (NTC), conventional tillage, and chiseling of no-tillage (Ch). Disturbed and undisturbed soil was sampled from 0 to 10, 10 to 20, 20 to 40, and 40 to 60 cm layers to determine degree of compaction, air capacity, near-surface optimum ratios, soil water retention characteristics, and soil physical quality index S. Initially, NT treatment had the significantly ( p < 0.05) lowest degree of compaction (87%), highest soil air capacity (0.104 cm3 cm−3), air capacity/total porosity ratio (0.261), and better water retention characteristics in the surface layer. Over time, Ch had improved the structure of the subsurface soil layers with the lowest degree of compaction (≈88%) and highest air capacity (≈0.140 cm3 cm−3), while the measured indices were poor in NTC. Irrespective of tillage, the surface layer showed resilience during the years without soil disturbance with low degree of compaction, increased water retention, and air capacity. NT could be a good soil management option for sugarcane production, while mechanical chiseling is advocated for ameliorating compacted soils.

Small biochar particles added to coarse sandy subsoil greatly increase water retention and affect hydraulic conductivity

AbstractSandy soils can benefit greatly from the addition of biochar, but the benefits depend on the properties of both the soil and the biochar. This study investigated the role of biochar particle size in controlling pore size distribution, hydraulic conductivity and water retention after careful mixing with coarse sandy subsoil. Intact commercial pellets of straw biochar (SB; approx. 8 × 5 mm) and ground pellets separated into 6 size fractions (median diameter 15, 33, 44, 81, 135 and 205 μm) were investigated at two concentrations (1.50 and 3.00 wt%). The results were compared with effects obtained with another feedstock (wood; WB) and another soil. Light microscopy and water retention measurements showed that smaller biochar particles settled into large existing soil pores, creating smaller interstitial pores to a much greater extent than larger particles. Accordingly, small particles (≤44 μm) had large enhancing effects on water retention and hydraulic conductivity in the medium suction range (pF1.7‐pF3.0), which were not found to a similar extent after the addition of larger particles (>81 μm). It was not possible to systematically distinguish the effects obtained with the three smallest particle fractions (SB15, WB18 and SB33). All effects measured were greatest at the highest biochar concentration level. In one soil, amendment with 3.00 wt% of SB15 decreased the fractional volume of drainable pores with an equivalent diameter of ≥60 μm from 31.3 vol% in the control to 19.1 vol%, while increasing the volume of pores in the 0.2–60 μm range that could potentially retain plant‐available water from 8.7 vol% to 20.1 vol%. Hydraulic conductivity at pF1.7 was increased by a factor of 10 (from 2.3 to 22.5 cm/day) and at pF3.0 by a factor of 14 (from 0.1*10−3 to 1.4*10−3 cm/day). Similar effects were observed in the other soil but at slightly different levels. The PDI version of the bimodal van Genuchten model was successfully fitted to measured water retention and log‐transformed hydraulic conductivity data (RMSE values in the interval 0.0011–0.0029 and 0.024–0.215, respectively). Dynamic simulation under variable field conditions including the hydraulic properties of biochar‐amended soil layers could be a useful method to investigate the effects on crop water supply, water and fertilizer utilization and yields.

Thermochemical valorisation of waste: pyrolytic conversion of horse stable residue into biochar

In this study, horse stable waste (horse manure, peat and wood sawdust) was processed under pyrolytic conditions. The chemical and physical properties of biochar obtained from different mixtures of horse stable residues were compared. All measurements followed an experimental design using a mixture model. This approach allowed the properties of any combination of ingredients to be predicted and the influence of each component on the final value to be estimated, with very good agreement between predicted and observed values. The results of the analysis of pH, polycyclic aromatic hydrocarbons (PAH), specific surface area (SSA) and CHNSO (carbon, hydrogen, nitrogen, sulphur and oxygen) showed that all possible combinations of materials can be used as soil amendments, since: an alkaline pH (>7) prevents soil acidification and a concentration of PAH below the limit (ΣPAH180 m2/g) and a different particle size distribution (PSD) provide habitat for microorganisms, increase water retention capacity and reduce greenhouse gas (GHG) emissions from the soil.