Ehsan Fartash Naeimi

The agricultural sector faces growing pressure to enhance productivity and sustainability, prompting innovation in machinery design. Traditional materials such as steel still dominate but are a cause of increased weight, soil compaction, increased fuel consumption, and corrosion. Composite materials—and, more specifically, fiber-reinforced polymers (FRPs)—offer appealing alternatives due to their high specific strength and stiffness, corrosion resistance, and design flexibility. Meanwhile, increasing environmental awareness has triggered interest in biocomposites, which contain natural fibers (e.g., flax, hemp, straw) and/or bio-based resins (e.g., PLA, biopolyesters), aligned with circular economy principles. This review offers a comprehensive overview of synthetic composites and biocomposites for agricultural machinery and equipment (AME). It briefly presents their fundamental constituents—fibers, matrices, and fillers—and recapitulates relevant mechanical and environmental properties. Key manufacturing processes such as hand lay-up, compression molding, resin transfer molding (RTM), pultrusion, and injection molding are discussed in terms of their applicability, benefits, and limits for the manufacture of AME. Current applications in tractors, sprayers, harvesters, and planters are covered in the article, with advantages such as lightweighting, corrosion resistance, flexibility and sustainability. Challenges are also reviewed, including the cost, repairability of damage, and end-of-life (EoL) issues for composites and the moisture sensitivity, performance variation, and standardization for biocomposites. Finally, principal research needs are outlined, including material development, long-term performance testing, sustainable and scalable production, recycling, and the development of industry-specific standards. This synthesis is a practical guide for researchers, engineers, and manufacturers who want to introduce innovative material solutions for more efficient, longer lasting, and more sustainable agricultural machinery.

The increasing effects of plastic pollution have led to the study of eco-friendly and biodegradable alternatives. The present study concerns the production and characterization of biocomposite films from starch, agar, and alkaline/peroxide-treated hemp fiber powder. In total, nine films were fabricated with variable ratios of starch–agar (0, 0.5, and 0.75) and hemp fiber (0, 15, and 30 wt.%). The physical, mechanical, and thermal properties of these films were evaluated. Tensile tests demonstrated that adding 30% hemp fiber increased Young’s modulus, while 15% fiber decreased tensile strength. In the SAH group, adding 1.5 g of agar significantly improved tensile strength and Young’s modulus, especially in the SAH30 sample. Finite element simulations of tensile tests showed remarkable agreement with experimental data. Machine learning models (SVM and GP) were used to predict tensile strength, with the SVM model using the RBF kernel showing the highest accuracy (R² = 0.938). Impact tests indicated that resistance was improved by agar, with the SAH group showing optimal stress distribution and energy absorption. Steady-state and transient thermal analyses showed that hemp fiber increased thermal resistance, and heat stress depended mainly on composition, especially agar and fiber. This research accentuates the potential of hemp fiber and agar to improve the properties of starch-based films and thereby opens routes toward sustainable material development.

Agricultural residues (such as straw and other nonmarketable plant waste) in Iran exceed 200 million tons annually, which can supply 10%–15% of the country's energy needs. The objective of this study was to investigate and estimate the biomass energy potential derived from crop residues in Iran using GIS mapping and artificial neural networks. The energy potential of the residues was determined by considering their heating value and the quantity of available residues. The available agricultural residues for the 10 crops studied were estimated to be 9,688,450 tons. Sugarcane and sugar beet contributed the largest shares, representing 32.33% and 25.72%, respectively. The largest quantities of sugarcane and wheat residues were found in Khuzestan province, amounting to 3,131,620 and 124,660 tons, respectively. For sugar beet, the maximum amount of residues was recorded in West Azerbaijan, with 719,140 tons. The total heating values for the residues were calculated to be 56,376 TJ for sugarcane, 18,212.36 TJ for wheat, and 42,887.32 TJ for sugar beet. The artificial neural network was able to predict the energy potential of biomass from the main products with a correlation coefficient of over 0.99 and the lowest error rate. GIS maps proved highly effective for rapidly analyzing the status of plant residues and their energy potential in each province. The findings suggest that agricultural residues in Iran have significant potential as a sustainable biomass energy source.

Concerns over dried product quality and energy consumption have prompted researchers to explore integrated techniques for improving quality and reducing energy use. This study investigates the effect of gamma irradiation pretreatment (0, 1.2, 2.4, and 3.6 kGy) on button mushroom slices, followed by thin-layer drying at 50, 60, and 70 °C. The results indicated that increasing irradiation dose and drying temperature significantly reduced drying time. The Midilli model provided the best fıt to the drying data (R² = 0.9969–0.9998). Artificial neural networks (ANN) accurately predicted moisture variations, achieving R² = 0.9975 and RMSE = 0.0220. The Support Vector Machine (SVM) algorithm, employing the Pearson universal kernel in normalized mode, also performed well, with R² = 0.9939 and RMSE = 0.0344. Similarly, in the k-nearest neighbors (kNN) algorithm with three neighbors (k = 3), the R² and RMSE values were 0.9888 and 0.0458, respectively. Gamma irradiation enhanced the effective diffusion coefficient (D_eff) to 10.796 × 10⁻⁸ m²/s, and reduced activation energy (E_a) to 11.09 kJ/mol. The highest heat utilization efficiency (41.1%) was observed at 3.6 kGy and 50 °C. These findings highlight the potential of integrating gamma irradiation pretreatment and advanced drying techniques to optimize energy use and improve the quality of dried mushroom slices.

The greenhouse sector is responsible for the largest proportion of total final energy consumption in agriculture. One effective method to reduce overall energy consumption in greenhouses is through an economical and efficient control strategy. In this study, a computer program was developed using the Visual Basic programming language to calculate the required heat flow for the growth and cultivation of greenhouse crops in most cities of Iran. The results indicated that the plastic covering material with double artificial plates was superior to other materials in maintaining internal heat. In the cities of Shiraz and Yazd, it was possible to cultivate pepper, tomato, cucumber, rose, lettuce, and strawberry with heat flow within the range of 0–24 kW and 0–30 kW, respectively. For colder cities such as Tabriz and Arak, the investigated parameter was calculated to be within the ranges of 24–70 kW and 17–63 kW, respectively. When comparing two other greenhouse covering materials, the minimum and maximum heat flow required for lettuce (glass with steel frame – Yazd and Shiraz) and rose cultivation (glass single plate – Tabriz) were observed to be 0 kW and 156.75 kW, respectively.

The geographical conditions of Azerbaijan have provided a favorable environment for planting all kinds of agricultural products. Therefore, in recent years, paying attention to the potential of biomass resources has been the subject of increasing research and discussions in this country. This study aimed to estimate the amount of biomass energy that can be acquired from agricultural residues in Azerbaijan. The energy potential of the residues was obtained by considering the calorific value and amount of available residues. For the year 2021, the total amount of available agricultural residues for the ten studied products was estimated at 1,099,346 tons. Cotton and barley had the highest amounts of waste with 47% and 14.47%, respectively. Also, the total heating value of residues was obtained 19610.4566 GJ. Therefore, according to the obtained results, part of the country's energy consumption can be supplied in this way.