Search Results (88)

The development of sustainable and efficient plant growth substrates is crucial for modern agriculture. This study assessed the potential of plant pellets formulated from various lignocellulosic residues, either with or without bamboo biochar (BB-char) and arbuscular mycorrhizal fungi (AMF), to support seed germination and early seedling growth. Four types of residues, including coconut coir (CO), corn cob (CC), leaves from the genus Dipterocarpus (DL), and teak leaves (TL), were combined with soil and paper waste to produce eight pellet formulations, with commercial peat pellets serving as a control. Chemical analyses revealed significant variation among the pellet types, with pH values ranging from 6.40 to 7.65, electrical conductivity (EC) from 3.64 to 11.62 mS cm⁻¹, and differences in organic matter, carbon, and nutrient contents [nitrogen (N), phosphorus (P), potassium (K)], reflecting the influence of residue type and the addition of BB-char and AMF. Phytotoxicity screening using aqueous extracts demonstrated species-specific responses, with cucumber exhibiting high tolerance across treatments, whereas chili seeds were more sensitive. Final germination percentage (FGP) and seedling growth assays in greenhouse conditions showed that pellets derived from CC and CO, particularly when combined with BB-char and AMF (T6 and T7), enhanced shoot and root development in carrot, chili, cucumber, and tomato, approaching the performance of commercial peat pellets. In contrast, DL- and TL-based pellets resulted in lower germination and growth. These findings indicate that both the physicochemical properties of lignocellulosic wastes and the combination of BB-char and AMF are important factors influencing pellet efficacy, highlighting the potential of CC- and CO-based pellets as sustainable peat alternatives for early-stage plant cultivation. Full article

Agricultural waste materials can serve as functional constituents in cement-based composites through three pathways: (i) organic bio-aggregates that lower density and alter thermal behavior, (ii) lignocellulosic fibers that control cracking and improve post-cracking resistance, and (iii) agro-ash supplementary cementitious materials (SCMs) that densify pore structure and reduce permeability when ash quality and curing are controlled. This review draws on 98 papers, with coconut shell aggregate and coir/coconut fibers as the core focus; agro-ash SCMs (notably palm oil fuel ash, POFA, and rice husk ash, RHA) enter where they clarify mechanisms or inform hybrid design. Rather than cataloging compressive-strength data, the synthesis is organized around controllable process inputs (feedstock conditioning, mix design, curing) and the interface-governed mechanisms that determine performance: interfacial transition zone (ITZ) character and pore connectivity. In coconut shell systems, density reductions come at a cost: elastic modulus drops and moisture sensitivity rises unless shell conditioning, particle packing, and matrix refinement are managed. In fiber systems, gains in toughness and residual capacity are bounded by mixing workability and by the long-term stability of the fiber–matrix bond under alkaline and wet–dry exposure. A mix must first meet strength, serviceability, and transport requirements before its embodied impact is compared with conventional alternatives. The contribution is to reframe these systems around controllable processing and interface mechanisms instead of tabulated strength values; preparation, treatment, and characterization data are consolidated into bounded design windows, an explicit core versus supporting evidence convention is applied, and sustainability is judged under functional equivalency rather than per-volume carbon. Full article

This study develops and assesses sustainable polyvinyl chloride (PVC) composites reinforced with agro-industrial waste fillers, integrating an ontology-based lifecycle assessment (LCA) framework to enhance sustainability evaluation. Agro-waste reinforcements, including rice husk ash (RHA), coir, bamboo fibre, and wood flour, were examined for their capacity to improve the mechanical and environmental performance of PVC and to advance circular economy objectives. Empirical data from UK PVC window manufacturing were integrated with Granta EduPack, Eco Design, Eco Audit, OpenLCA, and Protégé within a multi-layered semantic pipeline that links materials, processes, and environmental indicators. The agro-filler composites exhibited lower embodied energy and CO₂ emissions than glass fibre systems, with the PVC + 30% wood flour formulation achieving the highest efficiency. The ontology framework, comprising 25 classes, 7 object properties, 26 individuals, 16 data properties, and 218 axioms (generated automatically by Protégé’s metrics feature and verified with the Pellet reasoner), ensured semantic interoperability and consistent validation across datasets, enabling transparent and traceable sustainability analysis. Overall, coupling industrial data with digital LCA and ontology reasoning provides a reproducible pathway toward net zero-aligned, sustainable PVC composite manufacturing. Full article

Kenaf (Hibiscus cannabinus) core, an abundant renewable byproduct rich in cellulose and hemicellulose, has emerged as a candidate to replace or supplement peat and coco coir in soilless culture. This review synthesizes the physical, chemical, and biological performance of ground kenaf core and benchmarks it against conventional substrates. Kenaf core exhibits low bulk density (0.06 to 0.15 g cm⁻³), high total porosity (approximately 90%), and substantial plant available water (approximately 42%), supporting root aeration and water supply. Its pH (6.0–7.2) is near optimal for most crops, whereas electrical conductivity (EC) (3.2–4.7 dS m⁻¹) can exceed recommended ranges for salt-sensitive species, which necessitates pre-leaching or blending. Growth studies show comparable shoot and root performance in blends containing 20 to 70% kenaf, with composted kenaf often outperforming raw core. Pure kenaf generally requires more frequent irrigation and may shrink at high proportions. We outline processing variables such as core purity, particle size, composting, and leaching that govern stability and plant response, identify critical data gaps (including standardized EC and pH methods, and long-term shrinkage), and frame a sustainability agenda. Practically, studies to date indicate that pre-leached kenaf core, incorporated at up to about 70% by volume into peat or coir-based blends with structurally stable components such as perlite, can maintain growth and quality for several ornamental and bedding crops under greenhouse and nursery conditions. At the same time, reports of poor performance in some conifers and early suppression in direct-sown vegetables underscore that the suitability of kenaf-based substrates remains crop specific and dependent on material processing and management. Full article

Flexible barrier systems are widely used for landslide and debris flow mitigation due to their ability to dissipate impact energy through large deformations. Conventional systems, however, rely on steel mesh components, which are associated with high environmental impact and durability concerns. This study examines the feasibility of a sustainable coir geotextile composite barrier as an alternative flexible barrier for mitigating small-to-moderate landslides. A woven geotextile barrier was developed using multi-strand coir ropes and evaluated through a comprehensive experimental program involving physical and mechanical characterization, accelerated degradation testing, incremental static loading, vertical drop impact tests, and sustained load retention tests. The developed barrier exhibited a high mass per unit area of approximately 3750 g/m² and tensile capacities exceeding 2 kN at the rope level. Accelerated weathering tests revealed a limited reduction in tensile strength of approximately 5% after three years of exposure, whereas prolonged exposure of five years led to strength losses exceeding 70%, underscoring durability as a key design consideration. Static loading tests confirmed stable behavior up to 550 kg, and sustained loading of approximately 1700 kg was maintained over 48 h without loss of structural integrity. Vertical drop tests demonstrated impact resistance in the range of 6–51 kN, depending on the drop height, mass, and connection density. The results demonstrate that coir geotextile barriers can function as flexible, energy-dissipating composite systems suitable for sustainable landslide mitigation in moderate hazard scenarios. Full article

The citrus processing industry generates large amounts of organic residues whose sustainable management is a major environmental challenge. The aim of this study was to evaluate the effects of incorporating citrus-derived waste (CW) into coconut-coir-based substrates on tomato (Solanum lycopersicum L., cv. Proxy) under different irrigation regimes (I) in a factorial design (CW × I) with three replications. Each replicate consisted of six plants (pots), and the replicate was considered the experimental unit. Plants were grown in substrates amended with 0%, 6.25%, 12.5%, 25.0%, and 37.5% (v/v) citrus waste and subjected to three water regimes (100%, 75%, and 50% of the standard water supply). Plant growth, biomass allocation, yield components, and fruit quality traits were assessed. Results indicate that CW can be incorporated into coconut-coir substrates without detectable penalties in total production at low-to-moderate rates (6.25–12.5%) across all irrigation regimes. Yield reductions of 18% (from 3398 to 2789 g plant⁻¹) attributable to CW were observed mostly at the highest inclusion rates under moderate deficit irrigation (75% water supply), whereas under severe deficit (50% water supply), production declined across all CW rates, including 0%, indicating that water deficit has a dominant limiting effect. Fruit quality parameters were generally maintained or improved in amended substrates, particularly under reduced irrigation with deficit irrigation, generally increasing total soluble solids at 100%, 75%, and 50% WC (+13%, +19%, and +9%, respectively). Overall, these findings support the use of citrus waste at low-to-moderate proportions as a sustainable amendment for soilless tomato cultivation without marked negative effects on yield and fruit quality, enabling its use as a locally sourced substrate component within circular-economy strategies. Full article

Coconut coir, a key substrate in soilless cultivation, presents challenges for accurate moisture detection because of its complex internal structure, which limits the understanding of water infiltration and redistribution. This study employed RGB image recognition techniques combined with machine learning algorithms to systematically investigate the effects of initial moisture content (10%, 20%, and 30%), coarse-to-fine coir volume ratio (1:0, 1:1, and 0:1), and emitter discharge rate (1.0, 1.5, and 2.0 L h⁻¹) on wetting front morphology, water transport dynamics, and moisture variation within coir substrates. Morphological features of the wetting front were extracted from images and incorporated into three machine learning models—Support Vector Regression (SVR), Random Forest (RF), and Polynomial Regression—to construct a predictive framework for coir moisture estimation. The results showed that the SVR model achieved the best predictive performance in coarse coir substrates (R² = 0.89, RMSE = 3.37%), whereas Polynomial Regression performed best in mixed substrates (R² = 0.861, RMSE = 4.34%). All models exhibited lower accuracy in fine coir, particularly at high moisture levels. Under the same irrigation volume, increasing the initial moisture content enhanced both the water transport rate and the wetting front extent, with the aspect ratio (AR) decreasing from approximately 2.0 to 1.3, indicating a morphological transition of the wetting front from a “thumb-shaped” to a “hemispherical” pattern. Coarse particles facilitated vertical infiltration, while fine particles exhibited stronger water retention. By integrating RGB image recognition with machine learning approaches, this study achieved reliable prediction of coir moisture content and proposed an optimal management strategy using mixed substrates with an initial moisture content of 20–30% to balance infiltration efficiency and water-holding capacity while minimizing percolation risk. These findings provide a robust technical pathway for precise water management in coir-based cultivation systems. Full article

Coir is widely used as a soilless substrate yet partially replacing it with walnut shells in coir-based mixes may improve the sustainability of lettuce production and quality. This study evaluated the effect of incorporating walnut shells, with or without biochar, into coir-based substrates on lettuce yield and quality. Lettuce was grown in five substrates: coir (C), three coir–walnut mixes (1:1, 1:0.5, and 1:0.25 v/v), and one coir–walnut–biochar mix (C:W:B, 10:1.5:1 v/v). Increasing the walnut-shell proportion increased the cumulative leaching fraction, likely because of the coarse walnut particles, and reduced head fresh weight. However, shoot dry weight in the 1:0.5 and 1:0.25 mixes was similar to that in coir alone and reduced leaf nitrate content. In contrast, the C:W:B mix maintained head fresh weight (7.1 kg m⁻²) and shoot dry weight comparable to coir, while markedly lowering leaf nitrate concentration from 4130 to below 200 mg NO₃⁻ kg⁻¹ fresh weight. Leaf nitrate content increased linearly with shoot Zn uptake, suggesting a Zn-mediated control of nitrate accumulation. The coir–walnut–biochar mix emerges as a suitable alternative to pure coir, as it maintains lettuce productivity, reduces leaf nitrate accumulation, enhances anthocyanin content, and reflects more favorable physiological conditions by not requiring a strong activation of antioxidant defenses. Full article

This study investigates the Mode II fracture behavior of bamboo–coir–rubber (BCR) hybrid composite panels developed as sustainable alternatives for wood-based panels used in structural applications. The composites were fabricated using alternating bamboo and coir layers within a polypropylene (PP) thermoplastic matrix, with styrene–butadiene rubber (SBR) incorporated as an additive at 0–30 wt.% to enhance interlaminar toughness. Commercial structural plywood was tested as the benchmark. Mode II interlaminar fracture toughness (G_IIc) was evaluated using the ASTM D7905 End-Notched Flexure (ENF) test, supported by optical monitoring to study crack monitoring and Scanning Electron Microscopy (SEM) for microstructural interpretation. Results demonstrated a steady increase in G_IIc from 1.26 kJ/m² for unmodified laminates to a maximum of 1.98 kJ/m² at 30% SBR, representing a 60% improvement over the baseline and nearly double the toughness of plywood (0.7–0.9 kJ/m²). The optimum performance was obtained at 20–25 wt.% SBR, where the laminated retained approximately 85–90% of their initial flexural modulus while exhibiting enhanced energy absorption. Increasing the initial notch ratio (a₀/L) from 0.2 to 0.4 caused a reduction of 20% in G_IIc and a twofold rise in compliance, highlighting the geometric sensitivity of shear fracture to the remaining ligament. Analysis of Variance (ANOVA) confirmed that the increase in G_IIc for the 20–25% SBR laminates relative to plywood and the unmodified composite is significant at p < 0.05. SEM observations revealed rubber-particle cavitation, matrix shear yielding, and coir–fiber bridging as the dominant toughening mechanisms responsible for the transition from abrupt to stable delamination. The measured toughness levels (1.5–2.0 kJ/m²) position the BCR panels within the functional range required for reusable formwork, interior partitions, and transport flooring. The combination of renewable bamboo and coir with a thermoplastic PP matrix and rubber modification hence offers a formaldehyde-free alternative to conventional plywood for shear-dominated applications. Full article

This study aims to identify the most suitable slag waste-filled polymer composite for automotive braking applications. It employs a hybrid multi-criteria decision-making (MCDM) model that integrates the “method based on the removal effects of criteria” (MEREC) and the “root assessment method” (RAM) method. Eight slag waste-filled polymer composites, evaluated using seven performance-defining criteria, were considered in the MCDM analysis. The performance evaluation criteria included the friction coefficient, wear, friction fluctuations, friction stability, fade-recovery aspects, and rise in disk temperature. The criteria were weighted through the MEREC approach, which identified fade% (0.2890) and wear (0.2829) as the most important attributes in the assessment. The RAM was employed to rank the alternatives and suggested that the composite alternative with 60 wt.% slag waste and 5 wt.% coir fiber proved to be the best composition for automotive braking applications. The results were validated using nine MCDM models and Spearman correlation coefficients, which showed that the ranking of alternatives was consistent and stable even when the normalization steps of MEREC were swapped. Statistical validation demonstrated a strong predictive accuracy (p < 0.05) with a strong correlation coefficient (>0.8) alongside a minimal mean absolute error. Furthermore, sensitivity analysis was performed by examining several weight situations to determine whether the priority weights influenced the ranking of the composite alternatives. The findings from both the correlation and sensitivity analyses confirm the proposed hybrid MEREC-RAM model’s consistency and effectiveness. Full article

Floating-tray hydroponics is expanding for microgreen production, yet evidence on substrate performance under natural-light greenhouses remains limited. This study compared perlite, coconut coir, and a 1:1 (v/v) perlite–coconut coir mixture for amaranth (Amaranthus cv. ‘Diablo Rojo’) grown at the end of summer in an unheated greenhouse (CRD; 4 replicates). Perlite significantly improved establishment and yield: emergence reached 72.6% versus 46.1% in coconut coir and 35.1% in the mixture, with fresh biomass of 297, 171, and 119 g m⁻², respectively. The proximate composition exhibited consistency across substrates (protein ≈ 32% DW; crude fiber ≈ 32% DW; crude fat ≈ 2.5% DW), whereas nitrate concentrations varied between 1300 and 2500 mg kg⁻¹ FW, irrespective of the substrate. Vitamin C and total phenolics showed no significant variation, and β-carotene exhibited only a slight, non-significant increase in coconut coir. In contrast, mineral composition was substrate-dependent: perlite increased Ca (3626 ppm DW) and Mg (1094 ppm DW), while P and Fe were unaffected; Na was higher in perlite. These results indicate that under natural-light, unheated greenhouses, bioactive compounds are mainly influenced by environmental variability, whereas root-zone aeration drives Ca/Mg enrichment and yield. Perlite-based floating-tray systems represent efficient, low-cost strategies with potentially lower environmental impact, suitable for scalable urban and smallholder microgreen production. These findings, derived from a single-season trial in one unheated greenhouse, should be regarded as preliminary yet consistent with previous studies on microgreens. Future multi-season and multi-species experiments will help to confirm and expand on these results. Full article

The soil of the Trifinio region, the tri-national territory between Guatemala, Honduras, and El Salvador, is damaged by the expansion of monoculture, which decreases fertility and causes problems for local farmers. Furthermore, the region also faces issues of erosion and soil contamination. As an alternative to soil cultivation, soilless systems can be adopted, not requiring fertile soil, and significantly increasing yields and resource use efficiency. To encourage soilless technique application in the region, the aim of this study was to compare 18 different substrate mixes to identify the most suitable for the local cultivation of cucumber (Cucumis sativus L.). The substrates were obtained comparing three rates of peat and compost (0%, 20% and 40%, by volume) in factorial combination, with the remaining being either coir or pumice (filling component). Plant growth, flower setting, physiological status (relative chlorophyll content and leaf temperature), and plant production were evaluated. Highest yield was achieved with 20% peat, while compost (20% and 40%) was able to increase fruit length and improve the relative chlorophyll content, but did not affect total production. However, when focusing on environmental sustainability as an important standpoint, a peat-free substrate should be utilized even though the results favored the 20% peat treatment for production. Considering that the differences in production in favor of 20% peat treatment were of limited practical relevance. In regard to the filling components (coir and pumice) yields were unaffected and only minor parameters were changed. Based on the results obtained, a substrate consisting of 60% coir and 40% compost resulted in the best option for the soilless cultivation of cucumber in the Trifinio region, with both materials being sustainable and easily available for local farmers. Full article

Pothos (Epipremnum aureum G.S. Bunting), which belongs to the Arum family (Araceae Juss.), can be used for medicinal, ornamental, and pollutant-purifying purposes. Due to the usefulness of pothos, the market demand for this species is increasing. Our study attempts to fill in the shortcomings of previous studies on the effect of activated carbon and plant growth regulators on the ability of shoots to take root in vitro, as well as the effect of inexpensive and readily available materials on the transition of seedlings from in vitro to the greenhouse stage. To evaluate the shooting results, Murashige and Skoog medium (MS) was used, which included 6-benzylaminopurine (BA), kinetin (Kn), α-naphthaleneacetic acid (α-NAA), coconut water, activated carbon, and indole-3-butyric acid (IBA) in various concentrations and combinations. Our results showed that the MS medium with the addition of 2.5 mg/L BA and 1.0 mg/L Kn was optimal for propagation by shoots. In this variant, 2.86 shoots per explant, 1.87 cm of shoot length, and 1.59 leaves per shoot were obtained. Despite the fact that this treatment provided the highest total cytokinin concentration, it was significantly more effective than only BA (2.5 mg/L) and all combinations of BA+α-NAA or Kn+α-NAA. For rooting, the micro shoots obtained on the above medium were transferred to MS + 0.25 mg/L α-NAA + 0.5 g/L AC, which allowed for rooting by 93.33%, 1.93 roots per explant, and root lengths by 2.37 cm. This is higher than with the IBA-based treatment, which led to a shortening of the roots and a reduction in their branching. Acclimatization in a 1:1 mixture (by volume) of loamy garden soil (pH 6.2, 2.1% organic matter) and coconut coir (particle size 0.5–2 mm) gave 75% survival after 40 days. These results have opened up the prospect of developing an effective method for reproducing pothos species in vitro by organogenesis at the lowest cost. Full article

The micro-interface slip damping mechanism is insensitive to temperature, making it suitable for applications where the operating environment makes viscoelastic polymers ineffective. Damping material systems that rely on micro-interface slip typically embody randomly disposed interlocking units leading to complex material behaviors. This work studies a compressed coir vibration isolator that provides a lightweight, low cost and environmentally friendly alternative to common polymer devices. Under cyclic loading, it displays highly nonlinear hysteresis and a gradual change in properties based on the load history. The nonlinear hysteresis is captured with a Masing model, which has been shown to provide an adequate phenomenological representation of systems with large numbers of miniature stick-slip contacts. This study further explores a new way to enrich the Masing model by encoding time evolution using restoring force or displacement time integral, directly adopted from mem-models, a new family of models transferred from electrical engineering. In addition to using the data from the coir isolator, two additional datasets from clayey soil, another application of micro-interface slip damping, are used to validate the modeling approach. Full article

The growing need for sustainable materials in architecture has sparked significant interest in natural-fiber-based composites. Among these, coconut coir, a by-product of the coconut industry, has emerged as a promising raw material owing to its abundance, renewability, and excellent mechanical properties. The promise of coir-based composites in architecture is highlighted in this review, which also looks at their problems, advantages for the environment, manufacturing processes, and mechanical, thermal, and acoustic performances. The fibrous shape of the coir provides efficient thermal and acoustic insulation, while its high lignin concentration guarantees stiffness, biological resistance, and dimensional stability. Fiber-matrix adhesion and durability have improved owing to advancements in treatment and environmentally friendly binders, opening up the use of cement, polymers, and hybrid composites. In terms of the environment, coir composites promote a biophilic design, reduce embodied carbon, and decrease landfill waste. Moisture sensitivity, inconsistent fiber quality, and production scaling are obstacles; however, advancements in hybridization, grading, and nanotechnology hold promise. This review provides comprehensive, architecture-focused review that integrates material science, fabrication techniques, and real-world architectural applications of coir-based composites. Coir-based composites have the potential to be long-lasting, sustainable substitutes for conventional materials in climate-resilient architectural design if they are further investigated and included in green certification programs and the circular economy. Full article