Reduced Bulk Density Research Articles

Effect of rice hull amendment in green roof substrates

The use of waste and locally available materials could improve the sustainability of green roofs. Therefore, a study was conducted to evaluate the potential of a rice hulls in the organic and inorganic portion of green roof substrates. Three substrate mixtures were prepared at the site by mixing locally available materials. The substrate mixtures were designated as RPZV (rice hulls 6:1; pumice and zeolite mixture 2:1; vermicompost 2:1 by volume), PZR (rice hulls 2:1; pumice and zeolite 8:1), and PZV (pumice and zeolite 8:1; vermicompost 2:1). Measurements were performed including plant growth index, chlorophyll fluorescence, biomass accumulation on native and exotic plant species. Increased amounts of rice hulls in the substrate mixture had a significant effect on reducing bulk density up to 24%, increasing organic matter content up to 67% and maximum water holding capacity (WHC) of the substrate, but also had the lowest volumetric moisture values in the field measurements due to increased porosity and permeability of the substrate. Adversely, substrate mixtures with higher rice hull content experienced greater temperature fluctuations during the study period, which have resulted in increased plant mortality and stress for certain plant species during the study. As the organic part of the substrate, rice hulls caused a decrease on the salinity of the substrate by about 28% and provided higher survival rates and lower stress levels for A.schoenoprasum, C.creticus, L.spectabilis, D.chinensis and Sedum species. The results of the study suggested that, rice hulls may have the potential to be used in appropriate proportions due to their low bulk density, low salinity and resistance to degradation, leading to a reduction in the environmental impact of green roof construction.

Incorporating Cattle Manure Improves Hydraulic Properties and Enhances Infiltration Rates of Low‐Infiltrability Saline‐Sodic Soils

ABSTRACTDrylands present a significant challenge to global agricultural production, especially in dryland saline‐sodic soils, which are marked by poor structure and low infiltrability. Enhancing the infiltration capacity of these soils is crucial for enhancing soil health and optimizing land‐use efficiency. However, few studies have been conducted to improve soil physical structure and enhance water infiltration and storage capacity in saline‐sodic soils through agricultural waste. This study aims to evaluate the effectiveness of cattle manure amendments in improving water infiltration and related soil properties in dryland saline‐sodic soils. Our results show that mixing cattle manure into the topsoil soil significantly enhances infiltration rates, with the initial and the stable infiltration rates increasing on average by 64.5% and 52.1%, respectively, over the three‐year study period. These improvements are associated with a reduction in bulk density and soil compressive strength by 6.9% and 101.9%, respectively, as well as increases in total porosity, non‐capillary porosity, and soil organic matter by 6.6%, 24.7%, and 8.7%, respectively. In contrast, cattle manure mulching in the topsoil has no significant impact on infiltration and soil properties. Structural equation models reveal that soil water content, non‐capillary porosity, and total porosity are the primary properties influencing the stable infiltration rates, whereas total porosity, soil compressive strength, and non‐capillary porosity are key factors affecting the initial infiltration rate. Our findings demonstrated that incorporating cattle manure into the soil can effectively enhance the soil porosity properties, infiltrability, and organic matter content of saline‐sodic soils. These findings highlight the potential of cattle manure to improve soil physical properties and enhance water infiltration in low‐infiltrability saline‐sodic soils, offering a theoretical basis for addressing this issue in semiarid regions.

Thermophysiological Comfort Behaviour of Cut Protective Workwear Consisting of Filament Twisted Multicomponent Hybrid Yarn

Current cut protective gear is subject to several difficulties, such as the use of heavy fabric, complicated donning processes, lack of comfort and limited movement. When selecting the most comfortable cut protective fabric, it is important to consider the end users' specific needs. The aim of this study was to enhance the comprehension and optimisation of protective apparel for superior occupational safety and protection by exploring the intricate link between material composition, yarn structure and comfort parameters. Various combinations of filament twisted core sheath yarn consisting of stainless-steel/glass with high-performance polyethylene and polyester wraps were used to fabricate thermo-physiological comfortable cut protective workwear fabric. Twelve cut protective fabrics with the same areal density (200 g/m2) were prepared with 6-end satin weave using filament twisted core sheath yarn of five distinct linear densities (98.4 tex, 73.8 tex, 59.1 tex, 49.2 tex and 39.4 tex). These fabric samples were used to evaluate thermophysiological characteristics, including air permeability, dry and evaporative heat resistance, thermal conductivity, moisture permeability, wettability and moisture wicking according to the established standard. The cut protection of each sample was also measured according to EN 13997. The cut protection and thermo-physiological comfort attributes of cut-resistant clothing are greatly influenced by the proportion of core material (stainless-steel/glass) and yarn structural parameters (linear density and twist direction), which was observed by analysing the results. An increased core material percentage (stainless-steel/glass) contributes to increased fabric thickness and reduced bulk density, which influences the thermophysiological comfort attributes of the developed cut protective workwear fabric. Fabric made from a higher proportion of core material (stainless-steel/glass) with a lower bulk density exhibited an acceptable cut protection level and performed better in terms of thermo-physiological comfort attributes.

Comparative Analysis of Tillage Practices on Soil Characteristics in Vertisol for Groundnut-based Cropping System

Tillage practices in groundnut-based Vertisol systems is essential for improving soil health and maximizing agricultural productivity. This study investigates the impact of tillage practices and cropping systems on soil physical and chemical properties in the Vertisol region of Karnataka during the 2022-23 Kharif and Rabi seasons. Conducted at the MARS, UAS, Dharwad, the experiment utilized a strip plot design, comparing minimum tillage with crop residue incorporation (M1) and conventional tillage without residue (M2) across four cropping systems. Findings revealed that minimum tillage significantly enhanced soil properties, demonstrating improved porosity (52.14%), maximum water holding capacity (55.97%) and soil aggregate stability (62.42%) while reducing bulk density (1.27 Mg m⁻³) at the surface layer. Among cropping systems, the groundnut + pigeon pea combination showed superior soil characteristics, with porosity at 50.88%, MWHC at 55.05%, and reduced bulk density of 1.31 Mg m⁻³ at 0-15 cm depth. Additionally, minimum tillage led to higher soil organic carbon (7.65 g kg⁻¹) and available NPK levels (315.8 kg ha⁻¹ N, 44.06 kg ha⁻¹ P, 324.53 kg ha⁻¹ K), particularly in the groundnut + pigeon pea system. These findings emphasize the efficacy of conservation agriculture techniques, reinforcing existing research that highlights how minimum tillage and leguminous cropping systems enhance soil health and foster sustainable farming practices. Such results are pivotal for promoting sustainable agricultural development, as they illustrate that implementing these practices can lead to significant improvements in soil vitality, crucial for boosting crop yields and ensuring ecological stability in Karnataka's Vertisol region.

Achieving sustainable performance: synergistic effects of nano-silica and recycled expanded polystyrene in lightweight structural concrete

Lightweight concrete, particularly polystyrene concrete, has been extensively utilized in civil engineering for decades. The incorporation of waste expanded polystyrene (EPS) as a filler material in the production of lightweight concrete presents significant advantages from a circular economy perspective. Prior research indicates that increasing the proportion of lightweight aggregates, such as EPS, typically results in reductions in strength and bulk density. The utilization of substantial amounts of EPS waste in the formulation of structural polystyrene concrete is crucial for advancing sustainable construction practices. This study investigates the effects of varying nano-silica content on the bulk density, compressive strength, flexural strength, splitting tensile strength, and water penetration depth of structural polystyrene concrete. Concrete specimens were prepared by substituting 25%, 50%, 75%, and 100% of sand with EPS waste, while evaluating nano-silica contents of 0.75%, 1%, and 1.25%. The findings reveal that increasing the volume fraction of EPS corresponds to a decrease in the concrete’s bulk density. This research provides critical insights into optimizing structural lightweight concrete, thereby promoting advancements in sustainable construction applications.

Armazenamento e qualidade dos grãos de variedades crioulas de feijão-caupi em silo bolsa

ABSTRACT Storage is one of the main stages during grain production. The present study was conducted to evaluate the use of silo bags as an alternative for storing landrace cowpea grains. The experiment used samples of the Arigozinho, Manteiguinha, and Quarentão cowpea varieties from Cruzeiro do Sul - Acre, harvested in the 2021 crop season. The samples (500 g) were stored in raffia and silo bags for 30, 60, 90, and 120 days. The experimental design was completely randomized, arranged in a split-plot-in-time scheme (2 × 5) with four replicates. Storage conditions represented the plots: silo bags and raffia bags. The subplots comprised five storage conditions: 0, 30, 60, 90, and 120 days for each landrace cowpea variety. The insect species identified in all varieties was Zabrotes subfasciatus, with infestation ranging from 49% to 98% in raffia bags and less than 10% in silo bags over 120 days. A depreciation in grain quality was observed during storage in raffia bags. There was increase in electrical conductivity, fluctuations in water content, and reductions in bulk density and germination due to the higher degree of infestation in all the investigated varieties. The grains stored in silo bags showed minimal variations over the 120 days, maintaining their initial quality throughout the storage period. The bag silo storage system is an effective alternative for controlling Z. subfasciatus and maintaining the grain quality of the varieties Arigozinho, Manteiguinha, and Quarentão for a period of up to 120 days.

Production of hydrochar fuel by microwave-hydrothermal carbonisation of olive pomace slurry from olive oil industry for combustion application

This work is the first investigation on microwave-assisted hydrothermal carbonisation (MHTC) of real olive pomace (OP) slurry from the olive oil industry to produce hydrochars with improved fuel properties for combustion applications (e.g., in boilers). Experiments were conducted based on the central composite design of response surface methodology with two main process variables: temperature (180–250 °C) and holding time (2–30 min). Severity factors (log R0) were calculated from the above variables and used to explain the process effect in a simpler way. Increasing the MHTC severity resulted in significant changes in the structure of OP (studied by FTIR and NMR analyses) as well as reductions in yield, bulk density, volatile matter, and ash content in the hydrochars. The high-severity hydrochar was positioned in the lignite zone (van Krevelen diagram). It also exhibited substantial reductions in the alkali index (86.53 %), slagging index (76.89 %), and fouling index (96.07 %) compared to the raw material. Overall, the best conditions for hydrochar production with improved combustion characteristics were found to be 250 °C for 30 min (HHV = 28.45 MJ/kg, energy densification ratio = 1.25, equilibrium moisture content = 31.1 mg/g, comprehensive combustibility index = 2.94 × 10−7%2 min−2 ºC−3). These properties indicate that high-severity hydrochars could be utilised as biofuels for energy applications.

Composting and Liquid Formulations: Panacea to Better Yield in Agriculture: A Review

Liquid formulations, including aqueous, oil, and polymer-based products, often use polysaccharides to alter fluid properties. Liquid inoculants offer cost-effective alternatives to solid carriers, particularly benefiting small producers in India by overcoming transportation and processing challenges. Ideal liquid inoculants are non-toxic, low-cost, uniform, nutrient-supplemented, and support rapid microorganism release and growth. Effective formulations stabilize organisms, ensure easy field delivery, protect against environmental factors, and enhance microbial activity. Rich in nutrients and organic matter, compost enhances the texture, structure, and moisture retention of soil, improving soil qualities and crop productivity. It boosts soil enzyme activity and microbial populations, promoting nitrogen fixation and nutrient availability. Organic manure applications increase soil fertility, water retention, and reduce bulk density. Field and horticultural crops, such as potatoes, chillies, and tomatoes, show significant yield improvements with compost, which also suppresses plant diseases and weed populations. These findings underscore the importance of adopting liquid formulations and composting as sustainable agricultural practices.

Compost incorporation and wildflowers introduction for stormwater infiltration and erosion-control vegetation cover establishment in post-construction landscapes

Urban and suburban development frequently disturbs and compacts soils, reducing infiltration rates and fertility, posing challenges for post-development vegetation establishment, and contributing to soil erosion. This study investigated the effectiveness of compost incorporation in enhancing stormwater infiltration and vegetation establishment in urban landscapes. Experimental treatments comprised a split-split plot design of vegetation mix (grass, wildflowers, and grass-wildflowers) as main plot, ground cover (hydro-mulch and excelsior) as subplot, and compost (30% Compost and No-Compost) as sub-subplot factors. Wildflower inclusion was motivated by their recognized ecological benefits, including aesthetics, pollinator habitat, and deep root systems. Vegetation cover was assessed using RGB (Red-Green-Blue) imagery and ArcGIS-based supervised image classification. Over a 24-month period, bulk density, infiltration rate, soil penetration resistance, vegetation cover, and root mass density were assessed. Results highlighted that Compost treatments consistently reduced bulk density by 19–24%, lowered soil penetration resistance to under 2 MPa at both field-capacity and water-stressed conditions, and increased infiltration rate by 2–3 times compared to No-Compost treatments. Vegetation cover assessment revealed rapid establishment with 30% compost and 60:40 grass-wildflower mix, persisting for an initial 12 months. Subsequently, all treatments exhibited similar vegetation coverage from 13 to 24 months, reaching 95–100% cover. Compost treatments had significantly higher root mass density within the top 15 cm than No-Compost, but compost addition did not alter the root profile beyond the 15 cm depth incorporation depth. The findings suggest that incorporating 30% compost and including a wildflower or grass-wildflower mix appears to be effective in enhancing stormwater infiltration and provides rapid erosion control vegetation cover establishment in post-construction landscapes.

Mechanical strength and durability of GBFS geopolymer modified with metakaolin and functionalized beta-silicon carbide whiskers

Durability is crucial for materials development in construction and transportation industries. This paper investigates the mechanical strength and durability of alkali-activated granulated blast-furnace slag (GBFS) and modified geopolymer with varying contents of metakaolin (MK) and functionalized beta-silicon carbide whiskers (β-SiCw). Functionalized β-SiCw were prepared utilizing successful chemical methods. Macroscopic experiments tested mechanical strength, bulk density loss rate after exposure to severe conditions, and durability through sulfate wet-dry and freeze-thaw cycles. Microscopic experiments, including SEM-EDS, XRD, TG-DSC, and BET, revealed the microstructure mechanisms. Results showed that MK and functionalized β-SiCw improved mechanical strength by creating a more reactive phase and denser pore structures. Reduced bulk density loss rates and enhanced durability were observed, with a 71.9 % mass loss and 63.4 % compressive strength loss reduction after 50 freeze-thaw cycles, and a 12.2 % decrease in compressive strength loss after 56 days of sulfate wet-dry cycles, compared to control groups. The modified geopolymer had higher tortuosity and finer porosity due to more gel formation and nucleation sites, and functionalized β-SiCw effectively bridged micro-cracks and micro-pores.

Development and characterization of new lightweight waste-based plaster composites for building applications

The development of new environmentally friendly construction materials that incorporate waste as an alternative to traditional raw materials is becoming increasingly important and necessary for the construction sector. Gypsum plasters composites are characterised by their versatility and wide range of applications in precast construction due to their excellent technical performance and low cost. This research presents a new material that incorporates EPS waste in solution and recycled rubber aggregates as secondary raw materials, partially replacing traditional plaster material. In this way, partial mass substitutions of up to 12.5 % have been achieved compared to the reference composites without additions. The results show how the incorporation of EPS in solution allows a more homogeneous integration of the residue in the plaster composite matrix. Although it is true that the incorporation of both residues has slightly reduced mechanical resistance to bending and compression, reaching minimum values of 3.71 MPa and 5.08 MPa respectively, the results obtained greatly exceed the minimum values required by current regulations. On the other hand, in the study conducted with prefabricated false ceiling plates, it has been observed that the combined effect of both residues allows for greater resistance to simple bending than traditional composites, with a reduction in bulk density and thermal conductivity of up to 30.1 % and 26.5 %, respectively. Thus, this work presents a viable alternative for the development of new plaster composites that are more sustainable, lightweight and conducive to advancing towards the industrialisation of the construction sector.

Investigation of physicochemical and antibacterial properties of dill (Anethum graveolens L.) microencapsulated essential oil using fluidized bed method

The present study delves into the encapsulation of dill essential oil utilizing the fluidized bed coating methodology. The investigation focused on the impact of essential oil concentration and the application of maltodextrin and arabic gum as the primary and secondary coating agents. The dominant compounds in the dill essential oil were identified as limonene (32.32%), carvone (35.43%), and cis-dihydrocarvone (5.43%). The antimicrobial potency of the dill essential oil was evaluated, demonstrating notable inhibition against Streptococcus mutans with inhibition zone diameters ranging from 5.4 mm to 16 mm for concentrations between 250 μg/mL and 2000 μg/mL. For Streptococcus sobrinus, the inhibition zones measured from 6.6 mm to 18 mm across the same concentration gradient. An increase in maltodextrin concentration was associated with a decrease in moisture content, bulk density, and tapped density, while it improved microencapsulation efficiency and loading capacity. In contrast, a higher concentration of arabic gum increased moisture content, loading capacity, and encapsulation efficiency, but reduced bulk density and tapped density. Elevating the essential oil concentration increased all physicochemical properties of the microcapsules, except for tapped density. The optimal conditions for microencapsulation involve using a 2000 ppm concentration of dill essential oil with 75% maltodextrin and 0.1% arabic gum as carrier agents. Scanning electron microscopy images indicated that the microcapsule particles were nearly spherical with a smooth, intact surface. The release rate of phenolic compounds in a simulated saliva environment reached its maximum at 98.32% after 20 min, showcasing an efficient release profile.

Effects of autumn tillage with straw return on soil physical characteristics of corn fields in the eastern loess plateau

The implementation of unsuitable tillage practices has the potential to disrupt the structure integrity of the ploughed layer, as well as to influence the physical parameters of the soil. The application of a reasonable tillage method has been demonstrated to result in an improvement in the physical quality of the soil. Three autumn tillage practices have been implemented at the Dongyang Experimental Station of Shanxi Agricultural University since 2016: no-tillage with straw mulch (NTS), autumn rotary tillage with straw incorporation (RTS), and autumn plough tillage with straw incorporation (PTS). The impact of autumn tillage practices on soil physical quality in the 0–30 cm profile of spring corn fields was evaluated following the corn harvest in 2018 and 2019. The results showed that compared to the NTS treatment, the application of RTS was found to have decreased significantly by 9.6%–24.2% in soil bulk density, while it increased significantly by 12.8%–34.0% in total porosity and by 43.5%–146.4% in macroporosity at a depth of 5–10 cm. In comparison to the NTS treatment, the adoption of PTS was found to decrease significantly by 10.7%–30.5% soil bulk density, while it increased significantly by 9.9%–42.7% the total porosity and 23.1%–202.8% the macroporosity at a depth of 0–10 cm. Furthermore, the soil microporosity significantly increase of 7.5%–11.1% under the RTS treatment at the 0–5 cm soil depth and 7.7%–11.2% under the PTS treatment at the 10–20 cm soil depth. Soil physical quality index (SQI) significantly increase under the RTS and PTS treatments, with a 41.26% and 57.57% improvement, respectively, in comparison to the NTS treatment. In summary, the adoption of autumn tillage with straw return (RTS and PTS) demonstrated a reduction in soil bulk density, an increase in soil porosity, macroporosity, and a promotion of capillary porosity, and promoted the improvement of soil physical quality on the Eastern Loess Plateau when compared to no-tillage with straw mulch (NTS).

Impact of virgin and recycled polymer fibers on the rheological properties of cemented paste backfill

The addition of polymer fibers to cemented paste backfill (CPB) has shown promise in enhancing mechanical properties, although it also introduces changes in rheological characteristics. This study aimed to investigate the influence of different types of polymer fibers, namely virgin commercial polypropylene fiber (CPPF), recycled tire polymer fiber (RTPF), and recycled tire rubber fiber (RF), on the rheological properties of CPB mixtures through an experimental program, and provide design references for CPB pipeline transport. The results revealed consistent reductions in bulk density upon the incorporation of polymer fibers into CPB, alongside varying impacts on slump. Specifically, the addition of CPPF had a mild effect, while RTPF caused a continuous decrease in slump, and RF exhibited minimal influence up to a 4% concentration, with substantial effects thereafter. Moreover, the inclusion of fibers led to increases in apparent viscosity parameters, with RTPF inducing the most significant changes, followed by varying responses from CPPF and RF. When using RTPF for CPB reinforcement, emphasis should be placed on enhancing technical indicators related to viscosity such as energy consumption and pipeline wear during pipeline transport. Furthermore, adjustments were necessary to account for flow curve instability resulting from interactions between fibers and the paddle, with the data aligning well with the Bingham model. The addition of fibers, particularly CPPF and RF, primarily influenced plastic viscosity rather than yield stress, underscoring the limitations of slump tests in assessing rheology.

Biochar effects on salt-affected soil properties and plant productivity: A global meta-analysis

Biochar has been recognized as a promising practice for ameliorating degraded soils, yet the consensus on its effects remains largely unknown due to the variability among biochar, soil and plant. This study therefore presents a meta-analysis synthesizing 92 publications containing 987 paired data to scrutinize biochar effects on salt-affected soil properties and plant productivity. Additionally, a random meta-forest approach was employed to identify the key factors of biochar on salt-affected soil and plant productivity. Results showed that biochar led to significant reductions in electrical conductivity (EC), bulk density (BD) and pH by 7.4%, 4.7% and 1.2% compared to the unamended soil, respectively. Soil organic carbon (by 55.1%) and total nitrogen (by 31.3%) increased significantly with biochar addition. Moreover, biochar overall enhanced plant productivity by 31.5%, and more pronounced increases in forage/medicinal with higher salt tolerance than others. The results also identified that the soil salinity and biochar application rate were the most important co-regulators for EC and PP changes. The structural equation model further showed that soil salinity (P < 0.001), biochar pH (P < 0.001) and biochar specific surface area (P < 0.01) had a significant negative effect on soil EC, but it was positively impacted by biochar pyrolysis temperature (P < 0.05). Furthermore, plant productivity was positively affected by biochar pH (P < 0.001) and biochar feedstock (P < 0.01), while negatively influenced by biochar pyrolysis temperature (P < 0.01). This study highlights that woody biochar with 7.6 < pH < 9.0 and pyrolyzed at 400–600 °C under 30–70 t ha−1 application rate in moderately saline coarse soils is a recommendable pattern to enhance forage/medicinal productivity while reducing soil salinity. In conclusion, biochar offers promising avenues for ameliorating degradable soils, but it is imperative to explore largescale applications and field performance across different biochar, soil, and plant types.

Review on The Impacts of Biochar and Soil Organic Matter (SOM) Habitation toward the Soil Physico-Chemical Properties Conjugating with Maize (Zea mays) Growth Performance

This study studies the complex relationships between maize growth, soil organic matter, and soil physico-chemcial properties, with an emphasis on biochar. It examines how soil organic matter affects pH, bulk density, Cation Exchange Capacity (CEC), porosity, and nutrient levels. Biochar and soil organic matter increase soil pH by decomposing organic anions. With biochar, increasing soil organic matter concentration reduces bulk density, improving soil structure, porosity, and water retention. By increasing Cation Exchange Capacity (CEC), biochar and soil organic matter improve soil nutrient retention and delivery, which is essential for soil fertility. As a soil organic matter component, biochar provides macro and micronutrients, boosting soil production. The study also highlights the importance of soil porosity in plant growth, with sandy soils having high porosity and leaching susceptibility and soil organic matter. However, loam soils, made of sand, clay, and silt, have a balanced porosity and soil organic matter concentration that makes them ideal for agriculture. These data show how organic matter, and biochar, affect maize growth and soil physico-chemical properties. This finding has major implications for protecting the environment and sustainable agriculture.

A coffee biochar-mineral NP interaction: Boon for soil health

Low soil fertility, attributed to a deficiency in multiple nutrients, is causing a decline in the productivity of potatoes (Solanum tuberosum) in the Gawata district of southwestern Ethiopia. To address this issue, a field experiment was conducted during the Belg season (February to May) and Meher season (June to October) of the year 2024. The objective was to assess the response of potatoes to the combined application of nitrogen, phosphorus, and coffee biochar (BC) in relation to specific soil physico chemical properties under rainfed conditions. The treatments comprised various combinations of biochar (2.5, 5, 7.5 t ha-1) and inorganic NP (25, 50, and 75%) of the recommended dose (165 kg N ha-1 + 60 kg P ha-1 = 100% recommended dose of fertilizer, RDF), along with 20 t ha-1 of biochar and 100% inorganic NP, with a no-fertilizer treatment serving as the control. In total, there were 12 treatments and a randomized complete block design with three replications was employed for the experiment. The results indicated that the combined application of 75% inorganic NP and 7.5 t ha-1 of biochar significantly increased pH, organic carbon, total nitrogen, available phosphorus, cation exchange capacity, and exchangeable calcium and magnesium. Additionally, it reduced bulk density, exchangeable acidity, exchangeable aluminum, and exchangeable potassium compared to the values obtained from the initial soil test. Consequently, it was concluded that the integrated use of 7.5 t ha-1 of biochar and 75% of inorganic NP during the Belg season, or 25% of it during the Meher season, represents an optimal nutrient management strategy for potato production in the study area.

Advancements in Thermal Insulation through Ceramic Micro-Nanofiber Materials.

Ceramic fibers have the advantages of high temperature resistance, light weight, favorable chemical stability and superior mechanical vibration resistance, which make them widely used in aerospace, energy, metallurgy, construction, personal protection and other thermal protection fields. Further refinement of the diameter of conventional ceramic fibers to microns or nanometers could further improve their thermal insulation performance and realize the transition from brittleness to flexibility. Processing traditional two-dimensional (2D) ceramic fiber membranes into three-dimensional (3D) ceramic fiber aerogels could further increase porosity, reduce bulk density, and reduce solid heat conduction, thereby improving thermal insulation performance and expanding application areas. Here, a comprehensive review of the newly emerging 2D ceramic micro-nanofiber membranes and 3D ceramic micro-nanofiber aerogels is demonstrated, starting from the presentation of the thermal insulation mechanism of ceramic fibers, followed by the summary of 2D ceramic micro-nanofiber membranes according to different types, and then the generalization of the construction strategies for 3D ceramic micro-nanofiber aerogels. Finally, the current challenges, possible solutions, and future prospects of ceramic micro-nanofiber materials are comprehensively discussed. We anticipate that this review could provide some valuable insights for the future development of ceramic micro-nanofiber materials for high temperature thermal insulation.

Does biochar combined with cover crops improve health and productivity of sandy, sloping, and semi‐arid soils?

AbstractBiochar may improve the health of environmentally sensitive soils (i.e., low C, sandy, sloping) especially if combined with cover crops (CCs), but research is scant. We assessed how wood biochar (836 g C kg−1) applied at 0, 6.25, 12.5, 25, and 50 Mg ha−1 to sandy, sloping, and semi‐arid soils with and without CCs affects soils and crop yields in the central US Great Plains for 3 years. We measured crop yields and CC biomass each year, and most soil properties in Years 1 and 3. Biochar did not interact with CCs, suggesting the combination was no better than biochar or CC alone. In the semi‐arid soil, crop and CC did not establish due to persistent droughts. Biochar benefits were highly site‐specific. Biochar improved some soil properties but only in the sandy and sloping soils and at the biochar application depth (0‐ to 15‐cm soil depth). The 50 Mg biochar ha−1 improved the soil's ability to sorb water (0.08 cm s−1/2). Also, in the sandy soil, it increased soil organic matter concentration (2.5 g kg−1), soil pH (0.65 units), and available water (0.07 m3 m−3) only in Year 1, suggesting a biochar benefit in sandy soils is short‐lived. In the sloping soil, &gt;25 Mg biochar ha−1 reduced bulk density (0.16 Mg m−3) and increased soil mean weight diameter of water‐stable aggregates (0.58 mm), organic matter concentration (11.42 g kg−1), infiltration (9.35 cm), CC biomass production (0.27 Mg ha−1), and some microbial biomass groups. Biochar did not affect crop yields. Overall, &gt;25 Mg biochar ha−1 improved properties in some soils without interacting with CCs.

Behaviour of sewage sludge based lightweight aggregate in geopolymer concrete

The global challenge of sewage sludge disposal has encouraged innovative solutions aimed at reducing environmental impact while simultaneously addressing the growing demand for sustainable construction materials. This study aimed to develop treated raw sewage sludge-based lightweight aggregates with strength comparable to commercially available aggregates. Two methods, namely cold bonding and sintering, were employed for the formation of aggregates. The sintering method produced well-formed and hard aggregates, while the cold bonded aggregates exhibited weakness and disintegrated under the slightest pressure. The optimal mix for quality aggregates was found to be 10%–20% sewage sludge, 70%–80% fly ash, and 10% lime using the sintering method. In the sintering method, an increase in sewage sludge content resulted in the reduction of bulk density and specific gravity by 13% and 4% respectively due to the high organic content in sewage sludge, volatile gas release, and porous structure formation. When 10% to 20% sewage sludge content was added, water absorption of the aggregates also increased by approximately 2%. Physical properties such as individual pellet strength. aggregate crushing value reduced by 18%, 20% respectively and the aggregate impact value increased by about 9%. These aggregates were then used to produce lightweight geopolymer concrete, which exceeded the design strength by 7% for the aggregate containing 20% sewage sludge and demonstrated excellent physical properties. The use of waste-based aggregates offers advantages including savings in cost, sustainability, resource conservation, waste reduction, and reduced environmental impact, making them a valuable alternative to natural crushed stone aggregates in specific applications.