Tobacco is one of China's key economic crops, known for its wide distribution, high yield, and renewability. Tobacco stalk fibers (TSFs) share a similar chemical composition to wood fibers, making them a potential reinforcement for plant fiber composites. However, the waste tobacco stalk fibers raw material utilization rate is very low, and wasteful phenomenon is very serious. In this study, we prepared biodegradable TSF/PBAT composites using waste tobacco stalk fibers and polybutylene adipate-co-terephthalate (PBAT) through melt blending and injection molding techniques. The effects of different modifiers on the performance of the composites were systematically investigated, with a particular focus on their influence on the degradation behavior. The results showed that the waste tobacco straw fiber can be used as a reinforcing fiber for PBAT. The addition of modifiers significantly improved the mechanical properties of the composites and effectively slowed down the degradation rate in the soil environment. Among the modifiers, the combined use of maleic anhydride (MA) and hydroxylated multi-walled carbon nanotubes (OM) produced the best results, with the tensile strength and flexural strength of the composite reaching 17.3 MPa and 28.0 MPa, respectively-representing increases of 74.7% and 57.3% compared to the untreated composite. After 16 weeks of soil degradation, the mass loss rate of the MA/OM-modified composite decreased from 10.50 to 6.34%. This study provides a comprehensive exploration of the entire lifecycle of TSF-reinforced PBAT composites and offers important theoretical support for the resource utilization and value-added application of waste tobacco stalks in the field of green composite materials.

In the cotton fields in Xinjiang, residual film is present in the soil for a long period of time, leading to a decrease in the tensile strength of the residual film and increasing the difficulty of recycling. Existing technologies for residual film recovery focus on mechanical properties and ignore the dragging and tearing of residual film by cotton stubble. The effect of cotton straw-root stubble on residual film recovery can only be better determined by appropriate machine operating parameters, which are essential to improving residual film recovery. Through analyses of the pickup device, key parameters were identified, and a model was built by combining the FEM and SPH algorithms to simulate the interaction of nail teeth, residual film, soil and root stubble. The simulation revealed the force change law of residual film in root stubble-containing soil and the influence of root stubble. By simulating the changes in the characteristics of the residual film during the process, the optimum operating parameters for the nail teeth were determined: a forward speed of 1849.57 mm/s, a rotational speed of 5.5 r/s and a soil penetration angle of 30 degrees. Under these optimized conditions, the maximum shear strain, pickup height (maximum deformation) and average peak stress of the residual film were 1293, 363.81 mm and 3.42 MPa, respectively. Subsequently, field trials were conducted to verify the change in the impact of the nail teeth at the optimized speed on the recovery of residual film in plots containing root stubble. The results demonstrated that when the root stubble height was 5-8 cm, the residual film averaged a recovery rate of 89.59%, with a dragging rate of only 4.10% at crossings. In contrast, 8-14 cm stubble plots showed an 82.86% average recovery and an 11.91% dragging rate. In plots with a root stubble height of 5-8 cm, compared with plots with a root stubble height of 8-14 cm, the recovery rate increased by 6.73%, and the dragging rate of residual film on root stubble decreased by 7.81%. The percentage of entangled residual film out of the total unrecovered film was 30.10% lower in the 5-8 cm stubble plots than in the 8-14 cm stubble plots. It was confirmed that the effect of cotton root stubble on residual film recovery could be reduced under appropriate machine operating parameters. This provides strong support and a theoretical and practical basis for future research on the correlation between root stubble and residual film and how to improve the residual film recovery rate.

Microbial-induced calcite precipitation (MICP) is an eco-friendly soil stabilization technology widely applied to the solidification of aeolian sand. To further enhance the effectiveness of MICP in cementing aeolian sand, this study introduced wheat straw powder (WSP) as a reinforcing material and conducted experimental research on WSP-enhanced microbial cemented aeolian sand. By combining macroscopic physical and mechanical tests with discrete element method (DEM) simulations, this study systematically investigated the mechanisms by which WSP enhances microbial cementation and the mesoscopic failure characteristics of the material. The results indicated that adding WSP significantly increased the calcium carbonate content, resulting in uniform calcite deposition and encapsulation of sand particles. This enhancement increased the compressive strength and deformation resistance of the cemented sand columns, with a notable increase in strain at failure. DEM simulations further revealed that as the calcium carbonate content increased, macroscopic cracks within the sand columns evolved from single to multiple pathways, eventually penetrating the entire sand column along the loading direction. The internal bonding failure process could be divided into compaction, expansion, and rapid growth stages. Additionally, the uniformity of particle bonding in WSP-reinforced sand columns significantly impacted their macroscopic mechanical behavior, with uneven interparticle bonding likely inducing microcrack accumulation, leading to severe fracture patterns. These findings provide valuable insights for optimizing microbial cementation techniques for aeolian sand.

This study investigated the rheological and compression-permeability attributes of dredged slurry reinforced using waste rice straws. Recognizing the potential of natural waste fibers in geotechnical applications, this study aimed to elucidate the effects of fiber length and pretreatment processes on the relocation dynamics of the cemented slurry. A series of laboratory evaluations were conducted to gauge critical parameters such as flow consistency, viscosity, one-dimensional compression, and hydraulic conductivity. Results indicated that straw lengths greater than 0.075 mm significantly increased slurry slump flow due to altered surface area and water adsorption. Dynamic viscosity decreased with increasing straw length, yet overall performance improved with straw inclusion. The influence of immersing straws in pure water emerged as a determinant in the study. A 24-h pretreatment duration influenced the flowability, viscosity, and the structural integrity of the fibers. Based on the observations, the study deduces that straw powder finer than 0.075 mm, subjected to a 24-h immersion in pure water, optimally bolsters the flow properties of cemented waste slurry. While the benefits associated with elongated straw fibers necessitate exploration and validation, this work underscores the potential of rice straw as a sustainable reinforcement material in geotechnical endeavors, promoting waste recycling and reducing environmental impact.

Straw reinforcement improves the mechanical properties of soil matrices by uniformly incorporating dispersed straw materials, demonstrating advantages in strength enhancement, toughness improvement, and deformation control. This study aims to compare the reinforcement effects of different types of straw on soil and clarify the optimal method for straw-based soil stabilization. For wheat straw-reinforced soil using different processing methods (straw segment, straw powder, and straw ash) and mass contents, the basic geotechnical properties of each mixture were first determined. Triaxial tests were then performed under varying confining pressures and compaction conditions to assess the strength and modulus characteristics of the different reinforced soil specimens, and the microstructural characteristics of fiber-reinforced soil were investigated using scanning electron microscopy (SEM) analysis. The experimental results indicated that the strength and ductility of soils increased significantly with the addition of straw. The optimal performance of straw-reinforced soils occurred at 0.3% content. The elastic modulus increased by 85%, 64%, and 57% under confining pressures of 50 kPa, 100 kPa, and 200 kPa, respectively. At 200 kPa, straw segments provided the highest modulus increase of 57%, while straw ash achieved the greatest strength improvement of 97%. Furthermore, considering both compaction effects and cost efficiency, a compaction degree of 95% is recommended for straw-reinforced soil in engineering applications. Based on scanning electron microscopy, it was observed that the distribution characteristics of different straw types within the soil exhibit distinct patterns. This study aims to provide data to support the efficient utilization of straw materials in engineering applications.

The removal of straw from the seed bed to the inter-row prior to sowing maize is a critical agricultural practice. However, this process is inherently uncertain due to the variability in straw displacement. To investigate this interaction, this study developed a flexible straw model utilizing a discrete element approach, employing hollow cylinders to linearly connect the particles. Experiments were conducted to ascertain the mechanical properties of the flexible straw, with a focus on its biological and mechanical parameters. Subsequently, a full-coverage soil bin model of wheat straw was established to simulate the straw removal process, enabling the analysis of the interaction between the removal device and the straw during operation. The results indicate that varying operating speeds significantly enhance the influence of the straw removal device on the straw, thereby improving the straw removal rate. The maximum relative error of the traction force required for both simulation and experimental testing was found to be 21.27%. Additionally, a combined device was employed to simulate the straw removal process, with straw disturbance analyzed in both paired and single-direction scenarios. Finally, by comparing simulation results with bench test outcomes, the established model demonstrated a high degree of accuracy in simulating the straw displacement process. This research provides a valuable reference for the development of discrete element models for other crops and for enhancing the efficiency of straw removal devices.

This study investigated the conversion of cellulose from rice husk (RH) and straw (RS), two types of agricultural waste, into Carboxymethyl cellulose (CMC). Cellulose was extracted using KOH and NaOH, hydrolyzed, and bleached to increase purity and fineness. The cellulose synthesis yielded a higher net CMC content for RH-CMC (84.8%) than for RS-CMC (57.7%). Due to smaller particle sizes, RH-CMC exhibited lower NaCl content (0.77%) and higher purity. FT-IR analysis confirmed similar functional groups to commercial CMC, while XRD analysis presented a more amorphous structure and a higher degree of carboxymethylation. A biodegradable film preparation of starch-based CMC using citric acid as a crosslinking agent shows food packaging properties. The biodegradable film demonstrated good swelling, water solubility, and moisture content, with desirable mechanical properties, maximum load (6.54 N), tensile strength (670.52 kN/m2), elongation at break (13.3%), and elastic modulus (2679 kN/m2), indicating durability and flexibility. The RH-CMC film showed better chemical and mechanical properties and complete biodegradability in soil within ten days. Applying the biodegradable film for tomato preservation showed that wrapping with the film reduced weight loss more efficiently than dip coating. The additional highlight of the work was a consumer survey in Thailand that revealed low awareness but significant interest in switching to alternative uses, indicating commercial potential for eco-friendly packaging choices and market opportunities for sustainable materials.

With increasing global environmental awareness and concerns about food safety, biodegradable active packaging has garnered widespread attention. In this study, the stability and bioactivity of tea polyphenol (TP) were enhanced through the preparation of TP-ferric nanoparticles (TP-Fe NPs) using metal-polyphenol ion coordination. Moreover, the introduction of Fe ions can further enhance the antibacterial effects of TP-Fe NPs. Using the hydrogen bonding between konjac glucomannan (KGM) and zein to enhance the hydrophobicity and mechanical properties of the film. By employing KGM and zein as the matrix, we incorporated TP-Fe NPs as active fillers to create multifunctional active packaging films. This study aimed to meet the needs of food safety and sustainable development goals. The resulting film exhibited excellent water resistance (water contact angle: 117.73(degrees)), mechanical strength (tensile strength: 21.82 MPa, elongation at break: 94.30 %), ultraviolet-shielding ability (>99 %), biodegradability (5 days in soil), and antioxidant (>85 %) and antibacterial (>99 %) properties. Moreover, the film significantly reduced strawberry decay and extended its shelf life by 10 days. These findings provide new insights into the application of nanomaterials in active packaging, highlighting their potential and advantages in food preservation.

This study evaluates the potential of using rice straw waste as a sustainable alternative for managing the dredge sediment. The rice straw was used to reinforce the dredge slurry to realize treating the wastes with wastes. The dredge slurry could be relocated with altered rheological properties or reclaimed cultivable land by in-situ management. In this framework, the rheological and fertility properties of straw-reinforced dredge slurry were investigated with a 90-day degradation period. The increased liquid limit and fine content were observed regardless of the straw content and degradation time, and a decreased slump flow and increased dynamic viscosity were obtained after the addition of straw. Nutrients, including SOC, TN, P, and K, increase over time after straw reinforcement, suggesting effective land reclamation by straw blending. The increases were abrupt in the first 14 days, followed by a gently increasing rate. Soil pH decreases over time to the range more suitable for planting. Results suggest that effective straw reinforcement alters the rheological properties beneficial for vehicle transportation and improves the soil fertility for in-situ tillage. This study supplements the societal image of dredge materials and waste straws in engineering and environmental applications.

Iron (Fe) deficiency is a critical constraint on global food security, particularly affecting high-value horticultural crops such as strawberries (Fragaria x ananassa). This study examines the roles of melatonin and hydrogen sulfide (H2S) signaling in mitigating Fe deficiency stress by improving Fe bioavailability and enhancing plant resilience. Strawberry plants were cultivated under Fe-sufficient and Fe-deficient conditions and treated with 100 mu M melatonin and 3 mM dl-propargylglycine (PAG), an inhibitor of L-cysteine desulfhydrase (L-DES), which regulates H2S production. Fe deficiency significantly reduced chlorophyll content and photosynthetic efficiency while elevating oxidative stress markers such as hydrogen peroxide (H2O2), malondialdehyde (MDA), and electrolyte leakage (EL). Melatonin application alleviated Fe deficiency effects by enhancing Fe utilization, stimulating L-DES activity, and promoting H2S production. Melatonin also improved antioxidant defenses by boosting the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), as well as maintaining ascorbate-glutathione (AsA-GSH) redox dynamics. The addition of 3 mM PAG inhibited L-DES activity, resulting in reduced H2S levels and diminished melatonin-induced benefits, underscoring the essential role of L-DES-mediated H2S synthesis. Despite the presence of PAG, the co-application of 0.2 mM sodium hydrosulfide (NaHS) and melatonin restored Fe bioavailability, growth, and antioxidant capacity, suggesting a synergistic interaction between melatonin and H2S. This study highlights the potential of melatonin and H2S signaling to improve Fe homeostasis and mitigate oxidative stress in Fe-deficient plants. The findings offer strategies to enhance crop resilience and productivity in nutrient-deficient soils, thereby promoting sustainable agriculture and global food security.