Search Results (3,276)

In agricultural machinery visual navigation, accurately identifying the navigation line extraction region (NLER) at the center of the field of view is crucial for obtaining a precise navigation centerline. Although deep learning is the predominant method for NLER extraction, existing approaches face challenges in farmland environments characterized by densely distributed and irregularly extended leaves. These challenges result in unstable predictions, slow inference, and large model sizes that impede real-time applications. To address these issues, we propose a lightweight navigation segmentation residual network (LNS-ResNet), which integrates an inhibition–enhancement module (IEM) and a global convolutional residual block (GCRB). The IEM uses row–column one-dimensional convolutions to enhance vertical features between crop rows and suppress leaf-edge interference, producing more robust input features. The GCRB incorporates a full convolutional global attention (FCGA) mechanism to capture global context while preserving local spatial information. LNS-ResNet effectively reduces foliage interference and achieves accurate segmentation, with intersection over union (IoU) scores of 84.71% for crop row and 93.77% for path regions. Based on the segmentation output, we further propose a mask region determination-based navigation line extraction algorithm (MRD-Line), which directly identifies the NLER and connects the centerline within the mask without relying on line fitting. Deployed experiments on the Jetson TX2 demonstrate that the proposed method achieves both accuracy and efficiency, with mean angular deviations of 0.138${}^{\circ }$ (path) and 0.425${}^{\circ }$ (crop row), with average processing times of 64.1 ms (path) and 62.6 ms (crop row). Full article

This study investigates the ternary co-pyrolysis of Soma lignite (SL), a low-rank Turkish coal with high ash content, with two agricultural residues: pectin-rich sugar beet pulp (SBP) and lignin-rich peanut shell (PS). The primary objective is to clarify how biomass structure and blend composition control synergistic interactions, and how co-pyrolysis can upgrade the fuel properties of a low-quality coal while valorizing agro-industrial waste. Four SL:SBP:PS blends (80:10:10, 60:20:20, 40:30:30, and 20:40:40 wt.%) were tested by non-isothermal thermogravimetric analysis at 10 ${}^{\circ }$C min${}^{-1}$ under nitrogen. Differential thermogravimetric curves were deconvolved into four pseudo-components representing pectin/hemicellulose, cellulose, lignin/early coal, and main coal/mineral fractions. Mass-based deviation indices ($\Delta W$) and rate-based deviations ($\Psi$) from the additive prediction were calculated in three temperature regions to detect synergy and antagonism. The results demonstrate that interactions are strongly composition-dependent. The 40:30:30 blend exhibits the most pronounced synergistic enhancement, with average $\Delta W$ values of approximately −0.94 wt.% and −1.05 wt.% in the 350–500 ${}^{\circ }$C and 500–650 ${}^{\circ }$C ranges, respectively, while the 60:20:20 blend shows antagonistic behavior across all regions. For the 40:30:30 blend, the calculated higher heating value increases from 11.21 to 14.74 MJ kg${}^{-1}$, reflecting a gradual upgrading of the feed-mixture composition by biomass loading. Overall, the findings indicate that combining a pectin-rich, fast-devolatilising biomass with a lignin-rich, slower-decomposing biomass at an intermediate coal loading can shift mass loss to lower temperatures. This combination also produces measurable non-additive behaviour within the experimental noise level. In addition, it improves several feed-mixture indicators that are relevant to sustainable energy recovery from lignite-dominated regions. Full article

The valorization of secondary biomass streams is an important step toward more resource-efficient biorefinery concepts and reduced dependence on fossil-based materials. In this study, agricultural and forest residues, namely Atlas cedar cones, mixed conifer cones, hazelnut shells, walnut shells, coffee silverskin, and cocoa shells, were investigated as feedstocks for producing colloidal lignin particles. Lignin-rich extracts were obtained by Organosolv pretreatment using 60 wt% aqueous ethanol, followed by particle formation through solvent shifting and purification by ultrafiltration. A particular novelty of this work is that highly different feedstocks were processed under identical Organosolv and solvent-shifting conditions, enabling a direct comparison of their suitability for colloidal lignin particle production within one consistent process route. The feedstocks differed markedly in extractive content and chemical profile, as shown by sequential Soxhlet extraction and qualitative GC-MS screening. Despite these differences in extract composition, solvent shifting yielded colloidal lignin particles with largely similar properties. Dynamic light scattering showed hydrodynamic diameters of 65–88 nm immediately after precipitation for all samples except cocoa shell, which formed strong agglomerates. The ultrafiltration step further introduced an industry-relevant downstream purification stage by removing most water-soluble low-molecular-weight compounds before product evaluation. After purification and redispersion, particle sizes ranged from 121 to 389 nm, indicating partial aggregation but overall successful recovery of stable colloidal dispersions. All purified particle suspensions exhibited comparable antioxidant activity in the FRAP (ferric reducing antioxidant power) assay, ranging from 12.3 to 18.4 mg lignin per mg ascorbic acid equivalents. These results demonstrate that even chemically diverse biomass side streams can be converted into purified colloidal lignin suspensions with similar colloidal behavior and functional performance. The findings highlight the potential of low-value agricultural and forest residues as promising raw materials for lignin-based antioxidant and material applications. Full article

The growing demand for sustainable packaging materials has accelerated interest in biomass-derived carbon fillers as functional reinforcements for biodegradable polymer composites. This review critically evaluates the use of carbon materials produced from agricultural residues, particularly palm kernel shell (PKS) and coconut shell (CS), in biopolymer composite coating films for food packaging applications. Recent thermochemical conversion routes, including carbonization, activation, and catalytic graphitization, are discussed in relation to their influence on filler morphology, porosity, surface chemistry, and graphitic ordering. Particular emphasis is placed on structure–property relationships in composite systems containing matrices such as polylactic acid (PLA), starch, chitosan, gelatin, and polyvinyl alcohol (PVA). Published studies indicate that properly dispersed carbon fillers can improve tensile strength, thermal stability, ultraviolet shielding, and oxygen/water vapor barrier performance through stress-transfer mechanisms and tortuous diffusion pathways. However, excessive filler loading or poor interfacial compatibility frequently causes agglomeration, brittleness, and loss of transparency. Surface modification strategies including oxidation, silanization, and surfactant-assisted dispersion, are therefore reviewed as key approaches to optimize composite performance. Finally, current limitations involving migration safety, process scalability, and the lack of standardized testing protocols are discussed. Overall, PKS- and CS-derived carbon fillers represent promising sustainable additives for next-generation biopolymer composite packaging systems. Full article

This study explores the application of a bioflocculant derived from poultry eggshell waste for the removal of Chlorella spp. and related contaminants from agricultural wastewater using a statistically guided experimental design. In accordance with circular bioeconomy principles, eggshell residues were repurposed as a low-cost and sustainable biomaterial for water treatment. Chlorella spp. was selected as the target microalga due to its rapid proliferation, tolerance to eutrophic environments, and frequent presence in agricultural effluents. A two-level factorial design with center points was applied to evaluate the individual and interactive effects of key operational parameters, including pH, temperature, initial biomass concentration, and bioflocculant dosage. The highest biomass removal efficiency (94%) was achieved at pH 10, a temperature of 18.5 °C, a bioflocculant dose of 100 mg L⁻¹, and an initial biomass concentration of approximately 3.76 × 10⁷ cells mL⁻¹, with a contact time of 360 min. Under these optimized conditions, notable reductions were also observed in chemical oxygen demand (78%), nitrates (87%), phosphates (21%), and coliform bacteria (99.6%). The developed regression model exhibited strong predictive capability (R² = 0.97), indicating high reproducibility within the investigated experimental conditions. Overall, the findings suggest that eggshell-derived bioflocculants may represent a promising alternative to conventional chemical flocculants for agricultural wastewater treatment. High removal efficiency was achieved at relatively low dosages under operational conditions, supporting the potential of this approach for improving microalgae harvesting and the wastewater treatment processes. Full article

This review evaluates pretreatment strategies for blending the organic fraction of municipal solid waste (OFMSW) with agricultural residues to recover fermentable sugars. Three mechanistic benefits have been hypothesized for such blends: ash-mineral pH buffering, endogenous protein reduction of non-productive cellulase–lignin binding, and inhibitor dilution. These mechanisms are inferred from analogous lignocellulosic systems rather than measured directly in OFMSW–agricultural residue combinations, and their translation into saccharification gains remains substrate- and pretreatment-specific. A synergy index framework with a four-tier classification (true synergy, additive, substitution, and process complementarity) is applied to reclassify the available evidence, alongside an assessment of pretreatment chemistry, enzymatic hydrolysis outcomes, and techno-economic feasibility. Integrated sequential pretreatment, particularly acid-catalyzed steam explosion and deacetylation with mechanical refining, proved most robust for heterogeneous feeds. The strongest Tier I synergy is found for SO₂-catalyzed steam explosion of hybrid poplar–wheat straw (SI 1.29–1.33; 22% monomeric sugar gain). OFMSW combined with organosolv beechwood cellulose at 35–45% OFMSW reached 58–68% saccharification (44–46 g sugar L⁻¹), a Tier III–IV outcome. Matched-control saccharification data for OFMSW–agricultural residue blends specifically have not been reported. Co-processing corn stover with wet organic waste reduced CO₂ mitigation cost from $236 to $67 per ton CO₂-eq under bio-CNG upgrading. Formal synergy quantification, blend-specific inhibitor profiling, and high-solids process intensification are the central prerequisites for commercial translation. Full article

As agriculture moves towards green transformation and low-carbon production, the high energy consumption, environmental burden, and residue risks associated with conventional chemical fertilisers, pesticides, and disinfectants have become increasingly prominent. Non-thermal plasma (NTP) can generate reactive oxygen and nitrogen species (RONS) under near-ambient temperature and pressure conditions, while offering low chemical residue, high reactivity, and modular equipment design. It has therefore attracted growing attention in agricultural engineering and green agricultural input preparation. This review focuses primarily on studies published within the past five years, together with the selected foundational literature retrieved from Web of Science, Scopus, PubMed, MDPI, and ScienceDirect. It systematically examines the fundamental mechanisms, application modes, and representative agricultural scenarios of NTP, with particular emphasis on agricultural nitrogen fixation and fertilisation, seed treatment and seedling raising, crop growth regulation and protection, soil improvement and remediation, and postharvest preservation and safety treatment of agricultural products. Key technological advances are then summarised, including optimisation of discharge systems and reactor configurations, plasma–catalysis synergy, preparation of plasma-activated water (PAW) and plasma-activated mist (PAM), and the development and integration of specialised agricultural equipment. In addition, the current state-of-the-art (SOA) of artificial intelligence (AI) applications in plasma-process modelling, process-parameter optimisation, agricultural performance evaluation, and intelligent control is discussed. Existing evidence indicates that NTP is particularly relevant to controlled-environment agriculture, including greenhouse cultivation, hydroponics, and aeroponics, where discharge processes, water or nutrient solutions, and crop root-zone management can be coupled for in situ nitrogen supply, activated-medium preparation, and crop protection. However, reported effects remain strongly dependent on discharge type, energy input, reactive-species composition, treatment dose, crop species, cultivation system, and application route. Therefore, NTP-based agricultural technologies should be evaluated using consistent indicators, including energy consumption, product selectivity, reactive-species stability, treatment throughput, crop response, ecological safety, and system-level integration with AI and IoT. Future research should prioritise high-efficiency reactors, standardised evaluation frameworks, cross-scale mechanistic understanding, reliable datasets, and closed-loop intelligent control, thereby supporting the transition from laboratory studies to reproducible and application-oriented agricultural systems. Full article

The growing global demand for sustainable biotechnological routes for bioenergy production has paved the way for Brazil to position itself as a strategic leader due to its vast agricultural production and, consequently, agricultural residues, among which rice husk stands out. Although rice husk is widely used for energy cogeneration, its potential for producing high-value platform chemicals remains underexplored. This study aims to evaluate the production of value-added pyrolytic derivatives from rice husk by investigating the synergy between acid pretreatments and fast pyrolysis temperatures (350–600 °C). Thus, the experimental strategy involved intensifying the production of target compounds in the condensable fraction (bio-oil) from pyrolysis gases using different biomass pretreatments before fast pyrolysis according to the following conditions: (i) acid washing using acetic acid (10%), (ii) acid washing using nitric acid (0.1%) followed by impregnation using sulfuric acid (0.1–0.3%), and (iii) impregnation using sulfuric acid alone (0.1–0.3%). Fast pyrolysis was carried out over a temperature range of 350–600 °C using a pyroprobe microreactor coupled to a mass spectrometer (GC/MS). The best results, regarding overall volatile fraction, were observed when impregnation with 0.3% sulfuric acid was used prior to pyrolysis at 600 °C, resulting in around an 8.88-fold increase compared with untreated biomass. Nevertheless, the experimental conditions that favored the formation of our main chemical targets, such as levoglucosan, furfural and some phenols, were different. For instance, levoglucosan, furfural and eugenol increased by 21-, 10- and 22-fold, respectively, for biomass treated with HNO₃ (0.1%)/H₂SO₄ (0.2%) at 450 °C, whereas phenol and 4-vinylphenol increased by 35- and 14-fold at 500 °C. These findings can be considered satisfactory, highlighting the potential of the thermochemical conversion process as a valuable tool for the production of high-value chemicals from agricultural waste like rice husk. Full article

Sustainable phosphorus (P) management in agriculture requires a circular economy approach through the use of so-called bio-based fertilizers (BBFs). The properties of BBFs vary widely depending on raw materials and production processes. However, it is still unknown how these properties, and particularly the dominant P compounds determine not only the efficiency of BBFs in supplying P to crops, but also their effects on soil functioning and crop quality. This study aimed to evaluate the efficiency of a representative set of BBFs, and relate this efficiency to their composition and dominant P compounds. To this end, 14 BBFs were studied: four from water purification (struvite, vivianite, and sewage sludge with and without composting), four composts (municipal solid waste (MSW), vineyard residues, and two using olive husks), three vermicomposts (two homemade and one commercial), fish meal, digestate, and a commercial organic fertilizer. Phosphorus forms in BBFs were determined using ³¹P nuclear magnetic resonance spectroscopy (P-NMR). The BBFs were compared to a single superphosphate (SSP) in a pot experiment growing wheat in two different alkaline soils, one rich in iron (Fe) oxides and one rich in carbonates. The effects on critical elements in grain [magnesium, Fe, zinc (Zn), manganese, and copper] and enzyme activities related to soil functioning and P cycling were also assessed. The dominant P compound in the BBFs was orthophosphate (73.8–89.5% of the total P in the NaOH–EDTA extracts). The MSW had the highest polyphosphate content (4.1%), a complex inorganic P compound. The organic P content ranged from 9.2% (fish meal) to 25.5% (Moge). Sewage sludge and composted sludge contributed high levels of phosphonates (4.1 and 5.6% of extracted P). The most abundant organic P compound class was inositol hexakisphosphates (IHPs), and myo-IHP (phytate) was the dominant IHP stereoisomer (1.2–6.4%) followed by D-chiro-IHP and scyllo-IHP. Plant dry matter and grain yield with most BBFs were not significantly different from that of SSP in both soils, likely due to the high concentrations of phosphate in relatively soluble forms in most of the BBFs. Vivianite and sewage sludge resulted in significantly higher grain yield than SSP (43% and 40%, respectively) in the carbonate-rich soil, likely due to progressive phosphate dissolution, which decreased the precipitation rate of insoluble calcium (Ca) phosphates. The highest P recoveries were obtained with horse manure vermicompost (65% and 15% higher than SSP in the Fe oxide-rich and in the carbonate-rich soil, respectively), partially attributed to the decreased precipitation rate of insoluble Ca phosphates with the added organic matter. Some BBFs increased micronutrient concentrations in grains and most decreased the P-to-Zn ratio relative to SSP. Overall, phosphatase and β-glucosidase activities increased with carbon-rich BBFs. Most of the studied BBFs could effectively replace fertilizers from non-renewable sources, in some cases with better crop P recoveries. Furthermore, some BBFs could provide additional benefits to grain quality, in terms of micronutrient supply for humans, and soil functioning. Full article

Rice husk ash (RHA) is a silica-rich agricultural byproduct with significant potential in the development of sustainable porous materials. This study investigated the effect of calcination temperature and impregnation duration on the physicochemical and textural properties of KOH-modified RHA materials. The method used was calcination at different temperatures (500, 600, and 700 °C) combined with KOH impregnation for 19, 22, and 24 h. The prepared materials were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDX), Brunauer–Emmett–Teller (BET) surface analysis, and X-ray diffraction (XRD). FTIR analysis showed that increasing calcination temperature promoted the reduction in residual carbon-containing functional groups and enhanced the dominance of silica-related Si–O–Si vibrations. SEM observations revealed significant morphological evolution from heterogeneous fragmented structures at 500 °C to more interconnected porous frameworks at 600 °C, followed by partial densification and agglomeration at 700 °C. Semi-quantitative EDX analysis confirmed the silica-rich surface composition of the prepared materials, while XRD patterns indicated structural transformation from partially crystalline phases toward more stabilized silica-rich structures. BET analysis demonstrated that sample 2B, calcined at 600 °C with 22 h impregnation, exhibited the most favorable textural characteristics among the selected BET-analyzed samples, with the highest surface area and pore volume. Overall, calcination temperature and impregnation duration significantly influenced the structural evolution, pore development, and physicochemical characteristics of KOH-modified RHA materials. This study contributes to the development of sustainable biomass-derived materials and supports Sustainable Development Goal (SDG) 12, which is related to responsible consumption and production through the valorization of agricultural waste into value-added silica-rich materials. Full article

Biochar, a carbon-rich material derived from biomass pyrolysis, offers a promising pathway for valorising agricultural and industrial residues within a circular economy. This review analyses the evolution of biochar properties, including fixed carbon content, elemental composition, surface functional groups, porosity, pH, hydrophobicity, and thermal stability, as a function of pyrolysis temperature. The novelty of this work lies in the systematic correlation between the thermal history of biochar and its performance as a functional filler in polymer composites. In fact, increasing temperature enhances carbonisation and aromatic ordering, and in turn induces a transition from hydrophilic to hydrophobic behaviour, thereby promoting micro–mesoporous development. These shifts are critical for compatibility with polymer matrices and thus the production of light-weight, cost-effective, and environmentally friendly composite materials through processes such as melt extrusion and injection moulding. This study highlights how biochar can be tuned for compatibility: low-temperature biochar enhances adhesion in polar systems, while high-temperature biochar favours non-polar matrices, improving stiffness, thermal stability, and electrical conductivity. In biodegradable polymer composites, additional effects on crystallisation behaviour and degradation mechanisms emerge, further highlighting the complexity of designing biochar-reinforced systems. Full article

Lachancea thermotolerans is a non-Saccharomyces yeast characterized by its biotechnological potential, due, among other reasons, to its capacity to produce L-lactic acid and its impact on the organoleptic profiles of final fermented products. While its traits have been widely studied in fermented beverages and vinification, its potential use in other fermented foods, such as table olives, has been poorly studied. For this reason, the characterization and laboratory screening of Lachancea thermotolerans strains were performed in the present study. In this context, the potential use of forty L. thermotolerans strains in Spanish-style table olives was discussed based on pH and salt concentration tolerance, two key stress factors in the production process. Furthermore, the effect of oleuropein—the most abundant polyphenol in raw drupes—on L-lactic acid production was described to better understand and predict the behavior of L. thermotolerans under real conditions. In addition to stress resistance and L-lactic acid production, the suitability of the strains was assessed through their resistance to cycloheximide and copper, key indicators of tolerance to antimicrobial agents and agricultural residues. Finally, Principal Component Analysis of mixed data (PCAmix) and Hierarchical Clustering on Principal Components (HCPC) were performed to stratify and describe the intraspecific variability of this species, leading to the preselection of fifteen promising L. thermotolerans strains for use as starter cultures in Spanish-style table olive elaboration. Full article

This multi-level study investigates the economic resilience of mango farmers during the COVID-19 pandemic and their pesticide management practices under Thailand’s Q-GAP (Quality Good Agricultural Practices) certification standard. Field surveys compared the economic outcomes of 104 certified and 151 non-certified farmers from 2019 to 2023, together with pesticide use practices during the year preceding the 2024 survey. The sample was drawn from three provinces in northern Thailand: Phitsanulok, Phetchabun, and Phichit. The statistical analysis of the collected information produced several key findings. Certified farms achieved significantly higher production and sales than non-certified farms over the five-year period, mainly due to larger farm size and higher prices obtained from premium export market sales. Certified farmers also adopted a wider range of coping strategies during the pandemic, whereas non-certified farmers mainly reduced mango investments related to mango cultivation. Certified farmers reported significantly higher rates of insecticide and fungicide adoption, as well as significantly higher annual pesticide application frequencies across all three pesticide categories. Residue analysis showed no significant difference in organophosphate (OP) residues between the two groups; however, pyrethroid (PY) residues were significantly higher among certified farms. This pattern suggests that certified farmers may apply pesticides more intensively to satisfy the aesthetic requirements of premium export markets. Regression results further showed that herbicide application frequency was the only factor marginally associated with PY-type residue levels among certified farmers, although this finding should be interpreted cautiously because of the weak model fit. Full article

Agricultural residues can be used as substrate components for seedling production, contributing to cost reduction and waste management. This study evaluated the growth, nutritional composition, and physiological performance of Euterpe edulis seedlings cultivated under greenhouse conditions. It is one of the first to integrate morphological, nutritional, and physiological indicators to assess agro-industrial residues as substrate components. The experiment followed a randomized block design with five substrates and four replicates: commercial substrate; 100% crushed açaí and juçara seeds; 50% soil + 50% cattle manure; 50% soil + 50% crushed seeds; and 33.3% soil + 33.3% cattle manure + 33.3% crushed seeds. Plant height was not affected by substrate type, while stem diameter and leaflet length were greater in the commercial substrate. Root length was higher in the commercial substrate; however, root dry mass, surface area, and volume did not differ among treatments. Leaf number, leaflet width, leaf area, and Dickson quality index were similar across substrates, indicating comparable seedling quality. The shoot-to-root ratio was higher in seedlings grown in the substrate composed of 100% crushed seeds. Higher nitrogen concentration was observed in seedlings grown in substrates based on crushed residues, without differences in biomass, indicating the absence of a dilution effect. No statistical differences were observed for the remaining nutrients. Physiological parameters indicated adequate photosynthetic performance across treatments. Substrates based on crushed açaí and juçara residues showed comparable performance to the commercial substrate, representing a viable and sustainable alternative for E. edulis seedling production. Full article

Rapid and efficient elemental characterization of lignocellulosic biomass, such as grapevine cane residues, is essential for its effective utilization in energy and material applications; however, conventional analytical methods typically require extensive sample preparation and are therefore not suitable for rapid screening purposes. In this study, laser-induced breakdown spectroscopy (LIBS) based on TEA CO₂ laser ablation is applied as a direct and minimally destructive approach for the analysis of grapevine cane biomass. Emission spectra recorded in the 190–780 nm range enabled qualitative identification of the elements present in the biomass, supporting the applicability of LIBS for multi-element analysis of complex solid matrices. Quantitative determination of Mg, Ca, K, and Na was achieved using an external calibration approach with solid-spiked standards, yielding good linearity (R² = 0.976–0.990), with concentrations in good agreement with reference ICP–OES measurements. Plasma diagnostics indicated a temperature of approximately 10,500 K and an electron number density on the order of 10¹⁶ cm⁻³, supporting the assumption of local thermodynamic equilibrium (LTE) conditions. The results demonstrate that LIBS provides a rapid and practical tool for direct elemental screening of vine shoot biomass, with potential application in the assessment of agricultural residues for carbon-based material production and related valorization pathways. Full article