Journal of Agricultural Machinery

Abstract The study of soil behaviour in wheel interaction is complex due to the wheel's geometry and the varying soil conditions. Traditional measurements of soil parameters, such as the Bevameter and the cone penetrometer, are time-consuming and labour-intensive. This research presents a machine learning-based approach to predict soil sinkage in plate penetration tests, providing a suitable alternative to conventional methods. A soil bin with controlled experimental conditions was used to collect data, which was measured by a load cell and a magnetic encoder at a constant penetration rate of 4 mm s^-1. Two main machine learning models were selected; XGBoost and CatBoost. Hybrid versions of these models were developed using the Shrike Bird Optimisation Algorithm (SBOA). The results showed that the hybrid models outperformed the base models. The SBOA-CatBoost hybrid model achieved the highest accuracy on the training data with a coefficient of determination of 0.99, a mean square error of 2.81, and a mean absolute error of 0.79. The findings of this study highlight the potential of machine learning as a cost-effective and efficient alternative to traditional methods for measuring soil parameters. Further research is recommended to validate these models in different soil types and conditions.

Abstract Grain loss and impact damage are key indicators of wheat threshing quality. To explore the mechanisms of grain loss and damage, this study reproduces the wheat threshing process by establishing a discrete element model of wheat plants and a simulation platform for threshing devices. It conducts simulations on the movement laws of material flow and distribution laws of threshed materials under different conditions of feed rate, drum rotational speed, and deflector angle. Based on simulation calculations, the average velocity and force laws of wheat plants were obtained, and the influence laws of feed rate, drum rotational speed, and deflector angle on the threshing process were analysed. Through multi-objective parameter optimisation analysis, it is determined that when the feed rate is 7 kg s^-1, the drum rotational speed is 815 r min^-1, and the deflector angle is 70 degrees, the threshing performance of the device is relatively superior. Bench verification tests before and after optimisation showed that the impurity rate of wheat decreased from 29.19% to 25.02%, and the loss rate decreased from 1.61% to 0.95%, with the error between the model prediction results and the experimental results being less than 5%. The proposed model and optimisation strategy can directly guide the structural improvement of axial-flow threshing devices, significantly shorten the research and development cycle of harvesting equipment, and provide a reliable technical basis for efficient and low-loss wheat harvesting.

Abstract Mechanisation is crucial for enhancing agricultural productivity and operational efficiency, particularly in semi-arid regions. This study evaluated the performance of a CLAAS Talos 220 two-wheel-drive tractor equipped with a Shaktiman rotavator plough at tillage depths of 10 and 15 cm and forward speeds of 3, 5, and 7 km·h^-1 in northern Iraq during the 2023–2024 cropping season. The results showed that increasing depth and speed led to higher power losses resulting from wheel slippage, increased fuel consumption, and decreased field efficiency and actual ploughing depth. The highest power loss (6.96 hp) and lowest efficiency (66.60%) were recorded at a depth of 15 cm and a speed of 7 km·h^-1, while the lowest power loss (0.031 hp) and the highest efficiency (80.42%) were recorded at a depth of 10 cm and a speed of 3 km·h^-1. It was also shown that fuel consumption increases with depth, but decreases at higher speeds, and that the actual depth of ploughing decreases due to vibrations. The results indicate that operating at an average depth of approximately 10 cm and at an average speed of about 5 km·h^-1 is the optimal choice for energy use, improving field performance, and enhancing soil conservation.

Abstract In recent years, the adoption of agricultural tractors has advanced farm mechanisation, with the three-point hitch (TPH) system playing an important role in attaching implements. This study focuses on optimising the geometry of the TPH for the Massey Ferguson 475 (MF475) tractor through simulation in SolidWorks software and validation with laboratory measurements. The independent parameters, including (1) lift arm, (2) lift rod, (3) lower arm lengths, and (4) the distance between the lift rod-lower arm connection point and the lower arm pivot point, were systematically varied to find the optimal design. Additionally, we analysed the effects of the independent parameters on performance parameters such as virtual hitch point positions, mechanical advantage, and lifting force. Results indicated that the existing TPH of the MF475 tractor exhibits discrepancies from the ASABE standard, while the optimised design complies with it. The results showed that the length of the lower arms has the greatest influence on the position of the virtual hitch point. Additionally, the increase in the lengths of the lift arm, lift rod, and lower arm led to a decrease in the lifting forces. In contrast, the increase in the distance between the lift rod-lower arm connection point and the lower arm pivot point led to an increase in the lifting forces. Sensitivity analysis revealed that the distance between the lift rod-lower arm connection point and the lower arm pivot point is the most influential factor affecting lifting force and mechanical advantage.

Abstract The performance of mini hand tractors is crucial for improving productivity and operational efficiency in wetland rice farming. This study aimed to evaluate the effects of plough type, tillage pattern, and operating speed on mini hand tractor performance in the border region of Tarakan, Indonesia. Field experiments were conducted from September 2024 to January 2025 using a factorial design (3×5×2) and quantitative descriptive analysis supported by SPSS Statistics 26 for numerical comparison. Performance indicators included wheel slip (%), field efficiency (%), fuel consumption (L h⁻¹), and engine temperature (°C). Results showed that the rotary plough operating under the central tillage pattern at low speed (1 m s⁻¹) achieved the highest field efficiency (78%) and the lowest fuel consumption (1.306 L h⁻¹). In contrast, the disc plough with the central border pattern at high speed (2.3 m s⁻¹) produced the highest wheel slip (48%) and lowest efficiency (22%), indicating substantial performance losses due to excessive soil–wheel friction. Engine temperature increased proportionally with tractor speed, reaching up to 70 °C during high-speed operations. These findings demonstrate that optimising plough type and tillage pattern selection can enhance tractor efficiency by up to 56%, reduce fuel use by 0.8 L h⁻¹, and improve operational stability in wetland conditions. The study provides practical recommendations for selecting and operating mini hand tractors to enhance energy efficiency and sustainability in wetland mechanisation systems across Southeast Asian border regions.

Abstract Mechanisation of smallholder farming faces significant challenges, including high machinery costs, inefficient energy utilisation, and the lack of predictive design methodologies for multifunctional agricultural equipment. This study presents a low-cost modular multifunctional agricultural machine for smallholder applications, integrating soil-tool interaction modelling, nonlinear traction-slip analysis, coupled draft-power-torque relationships, structural stress evaluation, and lifecycle economic assessment within a unified analytical framework. Experimental validation conducted under three representative soil cohesion conditions (n = 36) demonstrated good agreement between analytical predictions and measured performance, with deviations of 8.7%, 9.2%, and 7.5% for draft force, torque, and structural stress, respectively. The proposed system exhibited energy consumption of 4.8–7.9 kWh ha^-1, achieved a 22–26% reduction in operating costs compared with commercially available petrol-operated smallholder tillage units of comparable working width and field capacity, and yielded an estimated payback period of 1.8–2.3 years. The incorporation of traction analysis accounting for wheel slip improved the prediction of energy requirements while maintaining seed spacing uniformity above 87%. Soil cohesion, penetration depth, and slip ratio were identified as the dominant parameters influencing power demand and structural loading. The proposed framework demonstrated improved energy efficiency, operational stability, and economic feasibility under the investigated operating conditions and shows potential for broader smallholder mechanisation applications.

Abstract Introduction
Soil compaction causes a decrease in water and air penetration into the soil, impairs root development, and consequently leads to a substantial decline in crop yield. The most rapid countermeasure is subsoiling. Subsoiler devices and the subsoiling operation are recognised among the most energy-consuming and heaviest soil tillage operations. Tillage tool vibration effectively reduces traction force, resulting in increased soil fracturing and mixing, which decreases soil adhesion. The objective of this research is to determine the optimal vibration frequency for an electrical oscillating subsoiler. This will lead to a modification of the conventional subsoiling process and the application of these research findings in routine agricultural subsoiling operations, particularly in the lands managed by the Khuzestan Sugarcane Development Company. Improving this operation can significantly reduce soil losses, energy consumption, and associated costs, given the vast annual volume and area involved.
Material and Methods
This research is a developmental and applied type. It contains the installation of an electric oscillation system, followed by the execution of treatments utilising the independent variables of the study, which consist of the vibration frequency of the subsoiler blade at five levels (0, 20, 30, 40, and 50 Hz) and soil moisture content at two levels, dry (5.5–5.8%) and moist (15–19%). The vibration generation system installed on the subsoiler consisted of two electrical circuits: one for supplying electrical energy from the tractor’s battery, and another for adjusting the vibration acceleration. This alteration was achieved by modifying the rotational speed of the vibrator motor, which, in turn, changed the frequency. The highest frequency of 50 Hz and the absence of vibrations could be achieved using the F300-2R2G-2 model of a programmable inverter drive, which supportsn both manual and automatic control. The five frequency levels, ranging from 0 to 50 Hz, were generated by the driver from within the tractor cabin, in accordance with the experimental design. The required electrical energy was also continuously supplied without fluctuations or interruption. The experiments were conducted in a pre-divided and prepared field, with three replications, utilising the experimental design of split-plots in the form of completely randomised blocks. Data obtained from the tests, including traction force, working width, working depth, and the cross-sectional area of the tilled soil, were compiled and statistically analysed using Excel and SAS software.
Results and Discussion
The results indicated that at high moisture levels, the working depth increased, while the working width and the effectiveness of the vibratory subsoiler decreased. Vibration levels at the 0.01 significance level had a significant impact on performance indicators, including working width, working depth, the cross-sectional area of tilled soil, and specific traction force. Under conditions of minimum moisture and maximum vibration, the highest effectiveness was achieved, meaning that the width, working depth, and disturbed soil area increased, while the specific traction force decreased. The maximum traction force occurred at the lowest frequency and under dry soil conditions. Therefore, in subsoiling operations, selecting a time when the soil is within the suitable moisture range and utilising higher frequencies of vibration leads to a larger area of disturbed and fractured soil. Additionally, a reduction in the required specific traction force further enhances the efficiency of the vibratory subsoiler.
Conclusion
The electric vibration system offers an innovative solution for vibration management and control by the operator. It offers a wider range for achieving optimal vibration in soils of varying textures, thereby maximising the efficiency of the tractor-tiller system. The application of variable-rate vibration enables electrification and is independent of the PTO.

Abstract Smallholder maize production in sub-Saharan Africa, crucial for regional food security, grapples with persistent yield gaps driven by labor-intensive planting practices and a critical lack of mechanization specifically designed to accommodate the traits of native plant varieties. This study characterizes three maize varieties (CML-539, Melkassa 3, and Melkassa 6Q) to develop design parameters for adaptive multi-crop planters. Geometric properties including length, width, and thickness were measured using digital calipers, with 100 seeds per variety. Analysis was performed for elongation, geometric and arithmetic mean diameters, surface area, projected area, transverse cross-sectional area, sphericity, flakiness ratio, aspect ratio, shape index, and roundness. Gravimetric properties including bulk and true densities, porosity, thousand seed mass, and angle of repose were systematically analyzed to optimize seed-handling mechanisms in planter design. Physical property analysis revealed distinct varietal requirements: CML-539's irregular morphology (9.42 mm length, 49.30% porosity) necessitates vibration-assisted metering and aerated delivery systems; Melkassa 6Q's uniform properties (71.11± 6.66% sphericity, 811.62 kg m^-3 bulk density) permit gravity-fed mechanisms; and Melkassa 3's intermediate characteristics of > 2.3 elongation ratio and 19.31% density variation require adjustable furrow openers of 25-30° rake angles. Geometric variability necessitates the implementation of adaptive solutions, such as curved seed tubes and adjustable furrow openers, to effectively prevent tilt and bridging. The resulting modular planter system, incorporating moisture-responsive metering, adaptive cell sizing, and aerated delivery, aligns with Ethiopia’s agroecological standards of 75 cm row spacing and depth range of 4 to 7 centimeters. This framework offers a scalable, sustainable model for precision smallholder mechanization, transferable to global maize systems.

Abstract Introduction
Planting rice seedlings in the main field followed by periodic or intermittent irrigation is often considered a form of dry farming. Research suggests that flood irrigation in rice cultivation is primarily favored by farmers for its ability to control weeds and ensure a reliable water supply, rather than necessarily enhancing rice quality or yield. Depending on the rice variety, intermittent irrigation can sometimes improve both the quality and yield per unit area. The transplanting process in this method can be carried out manually without machinery or through mechanized methods using a planter.
Materials and Methods
Conventional rice transplanters designed for use in flooded land are not suitable for transplanting in dry land farming due to technical constraints. Therefore, it is necessary to develop a specialized rice transplanter tailored for such soil condition. This transplanter encompasses essential components, including a furrow opener, coverer, seedling storage tank or tray, seedling mechanism (distributor), seedling transfer mechanism (seedling transport piston), end separator for seedlings in the soil, power transmission system, depth adjustment shoe, and main and sub chassis. To evaluate the planter's performance, various parameters were assessed, including the percentage of lost plants, the average vertical angle of plant orientation, the average spacing between plants in the crop row, and the average number of seedlings per plant. Moreover, a factorial randomized block design was employed, with three replications for each level of the independent variables. The independent variables were forward speed (X1) at three levels of 0.25, 0.5, and 1 m s^-1, planting depth (X2) at three levels of 4, 8, and 12 cm, and the size of the outlet opening of the seedling tray (X3) in three levels of 10, 15, and 20 mm.
Results and Discussion
The developed single-row planter features key specifications, including a working width of 250 mm, a power requirement of 0.57 kW, a theoretical field capacity of 0.06 ha h^-1, and a field efficiency of 66.67%. The research findings revealed that forward speed, planting depth, and outlet opening size, along with their interactions, significantly impact the percentage of lost plants at the 99% confidence level. Among the three levels of forward speed (X1), the best speed level is 0.25 m s^-1, as it results in the lowest percentage of lost seedlings. As the forward speed increases, the percentage of lost seedlings increases. The lowest percentage of lost plants (Y1) occurs at the planting depth of 8 cm and an outlet opening size of 20 mm. Furthermore, forward speed, planting depth, and their interaction have a noteworthy influence on the vertical angle of plants are established, at the 99% confidence level. With the increase of forward speed and planting depth, the average vertical angle of seedling establishment deviates from the vertical position. The forward speed of 0.25 meters per second and the planting depth of 8 cm show the best results for the establishment of seedlings. The sole factor affecting the spacing between plants in the row is the forward speed. The size of seedling tray’s outlet opening significantly affects the number of seedlings per plant at the 99% confidence level, while planting depth affects it at the 95% confidence level.
Conclusion
Given the recent water crisis, adopting the dry rice farming method and using transplanters offers a viable solution for managing and conserving water in agriculture. Implementing dry planting with a custom-made transplanter yields several benefits, including reduced water consumption, lower cultivation costs, improved soil aeration, increased efficiency, and simplified planting processes. Utilizing this transplanter is an effective strategy to decrease both the time and expenses related to transplanting, while also mechanizing rice planting in dry fields.

Abstract Introduction
Tillage of rainfed lands is performed using moldboard plows to a depth of 30 cm. Due to the influence of soil surface roughness and crop residues on moisture absorption and erosion reduction, investigation of the relationship between tillage implements’ performance and the aforementioned factors is essential. Therefore, considering the importance of preserving precipitation and preventing soil erosion, this study was conducted to investigate and optimize the effects of forward speed and tillage depth on soil surface roughness and the percentage of buried crop residue using response surface methodology.
Materials and Methods
This research was conducted in the Khomeyn region, Iran during the 2023-2024 growing season, utilizing a moldboard plow and an MF399 tractor. The objective was to investigate the effects of plowing depth and speed on soil surface roughness and the burial of plant residues. Soil surface roughness was measured using a pin meter, while the percentage of burial of plant residues was determined using image processing techniques and ImageJ software. Wheat straw residue with an initial moisture content of 8-9% was uniformly distributed at a rate of 100 g m^-2 along the designated paths. Images were captured before and after the tillage operation for subsequent processing and analysis.
To optimize the process, a central composite design (CCD) with three levels of speed (5, 7.5, and 10 km h^-1) and three levels of tillage depth (17.5, 22.5, and 27.5 cm) was employed. The objective was to determine the optimal factor levels for maximizing surface roughness and minimizing residue burial. Data were analyzed using a second-order model and Design Expert V11 software. The best model was selected based on statistical criteria.
Results and Discussion
Modeling soil surface roughness and crop residue incorporation revealed that the second-order regression model, with high coefficients of determination (R² = 0.983 and 0.96), was capable of accurately predicting these indices. The interaction effects of tillage speed and depth were significant (P < 0.01). In this study, the effect of tillage depth on soil surface roughness was greater than that of tractor speed. The regression model indicated that tillage depth plays a primary role in the amount of crop residue incorporation. Moldboard plowing demonstrated that increasing depth, particularly at high speeds, leads to increased roughness and residue incorporation, whereas increasing speed, especially at shallow depths, reduces roughness and increases incorporation. The maximum roughness was observed at the deepest tillage depth and lowest speed, while the shallowest depth and highest speed resulted in the minimum roughness.
Tillage depth and speed influence soil surface roughness and bulk density. Higher speeds decrease furrow depth and ridge height; thus, lower speeds are recommended for creating greater roughness. The highest residue incorporation (85%) was achieved at a depth of 27.5 cm and speeds of 5 and 10 km h^-1, while the lowest (70%) occurred at a depth of 17.5 cm and a speed of 5 km h^-1. Depth was more influential than speed, and nonlinear models are necessary for more accurate modeling. The developed model, with a desirability of 81%, provides the maximum roughness (10.96 cm) and minimum residue incorporation (69.34%) for a moldboard plow at a speed of 5 km h^-1 and a tillage depth of 17.5 cm.
Conclusion
This study investigated the effects of conventional tillage methods in dry land areas on soil surface roughness and the extent of crop residue burial. The results indicate that increasing tillage depth leads to an increase in both indices, while reducing tractor speed increases roughness and decreases residue burial. The optimization model revealed that at a speed of 5 km h^-1 and a depth of 17.5 cm, minimum roughness and maximum residue incorporation can be achieved. To improve regional tillage practices, it is advised to conduct further research into the long-term effects of different tillage systems. This effort will ensure a well-informed selection and implementation of the most effective methods.
Acknowledgment
The authors gratefully acknowledge the financial support provided by the University of Lorestan.

Abstract Introduction
One of the most important parts of agricultural operations is tillage, which accounts for about 60% of the total energy consumed. Therefore, reducing tillage energy demand by lowering the number of passes through the development of cost-effective machinery is highly essential in modern farming. One of the main implements that helps farmers achieve this is the disc harrow. As the most important secondary tillage tool, the disc harrow improves soil structure, breaks up clods, and increases the penetration of water and air into the soil. However, its optimal performance is influenced by parameters such as disc diameter, disc edge type (toothed or plain), disc gang angle, and tractor forward speed. Soil bins, as controlled environments for testing tillage tools, serve as an ideal alternative to agricultural lands. They allow accurate simulation of field conditions while minimizing the effects of climate change and variable soil properties.
Materials and Methods
The present study was conducted with the aim of designing, constructing, and evaluating a disc harrow carrier chassis in the controlled environment of a laboratory soil bin. First, the design phase was carried out using SolidWorks 2020 software, followed by an analysis of the design performance under maximum load using the von Mises method. The next step was the construction of the design. After construction, the evaluation phase was performed by examining the effects of four independent input variables: forward speed (6.43 and 13.15 m min⁻¹), soil moisture content (2.37 and 13.25 percent on a wet basis), disc edge type (plain or toothed), and disc gang angle (0, 15, and 30 degrees), on the dependent output variable, draft force. Each test was replicated three times, resulting in a total of 72 tests.
Results and Discussion
The results showed that the engineered chassis exhibited sufficient strength during the initial evaluation tests, with all components performing well. The findings indicated that increasing forward speed and disc gang angle led to higher draft force, while higher soil moisture levels reduced draft force. Under low moisture conditions, plain discs generated greater draft force; however, this trend reversed as moisture increased. The highest draft requirement (3.588 N) was observed for plain discs at 2.37% moisture, while the lowest (1.724 N) occurred at 13.25% moisture. At a forward speed of 6.43 m min⁻¹, plain and toothed discs required equal draft, but at 13.15 m min⁻¹, the toothed discs required substantially more draft.
Conclusion
The experiments showed that there was no significant difference in draft force between disc gang angles of 0 and 15 degrees. However, increasing the angle from 15 to 30 degrees caused a significant rise in draft force. This indicates that the initial increase in gang angle has a smaller effect, but beyond 15 degrees the impact becomes more pronounced. Therefore, selecting an appropriate disc gang angle can help reduce fuel consumption and improve the productivity of agricultural machinery. Both increasing disc gang angle and forward speed raise draft force because soil resistance to disc movement increases. At higher speeds, the disc must exert more force to cut and move the soil, leading to higher energy consumption and greater equipment wear. Conversely, at lower speeds, draft force decreases, but tillage efficiency may be reduced and plowing uniformity may be affected.

Abstract Soil properties play a fundamental role in the success of agricultural operations through their impact on crop growth and quality, as they determine their ability to retain water and absorb nutrients, and affect soil aeration and the root system. The aim of this study is to predict bulk density and resistance to soil penetration under different moisture levels during tillage operations. It includes four moisture levels: 7, 14, 22, and 28%, and three types of plows: the moldboard plow, chisel plow, and disc plow. Moreover, soil samples were collected at two depths: 15 cm and 30 cm. The change in the physical properties of the studied soil is also measured during the growth periods of wheat crop (after tillage, beginning of the season and end of the season). The study is conducted in Al-Qurna district, north of Basra Governorate, Iraq, in clay loam soil. The results are analyzed and mathematical equations are obtained to predict the studied properties using the response surface methodology. The obtained results indicate that soil moisture during plowing, plow type, soil depth, and crop growth periods have a significant effect on soil bulk density and penetration resistance. The 14% moisture treatment is superior, recording the lowest bulk density and lowest penetration resistance of 1.12 Mg m^-3 and 1133 kN m^-2, respectively. While the 28% moisture treatment provided the highest bulk density and highest penetration resistance of 1.22 Mg m^-3 and 1379 kN m^-2, respectively. The results also show that increasing the soil depth from 15 to 30 cm increases the bulk density and soil penetration resistance, by 12 and 45.70%, respectively. Plowing with a disc plow improves soil properties, giving the lowest bulk density and penetration resistance of 1.12 Mg m^-3 and 1074 kN m^-2, respectively. While using the chisel plow leads to recording the highest bulk density and penetration resistance, which reached 1.22 Mg m^-3 and 1442 kN m^-2, respectively. As for the moldboard plow, the bulk density and soil penetration resistance reached 1.18 Mg m^-3 and 1282 kN m^-2, respectively. The growth periods have a significant effect on the studied soil properties where the beginning of the growing season provided the lowest bulk density. The bulk density reached 1.17, 1.13, and 1.23 Mg m^-3 for the periods after plowing, at the beginning of the season and its end, respectively. While the penetration resistance after plowing is superior with the lowest resistance compared to the beginning of the season and its end, as it reached 897, 1327, and 1573 kN m^-2, respectively. The results of data analysis show that the obtained mathematical models accurately and efficiently predict bulk density and soil resistance to penetration under the experimental conditions, with a high coefficient of determination (R²) of 0.6460 and 0.8114 for the bulk density and penetration resistance, respectively.

Abstract Introduction
Walnut (Juglans regia L.) is a highly valued horticultural product, and significant efforts are underway to enhance its production in Iran. Despite the development of various tools aimed at increasing productivity and improving harvesting efficiency, over 90% of walnuts in Iran are still harvested manually, often with the aid of specialized tools or by striking the trees with sticks. Although numerous mechanical devices have been introduced, the considerable height of walnut trees and the asynchronous ripening of the nuts continue to make traditional harvesting methods predominant. In this research, a novel walnut peeling system incorporating a horizontally rotating cutting plate was developed and evaluated. The cutting plate, designed with specific grooves and curvature, aims to enhance the mechanical efficiency of the peeling process. This analysis investigates the influence of rotational speed and groove depth on system performance. In addition, the life cycle assessment is conducted to evaluate the environmental and operational impacts of the proposed system, with comparative analysis against conventional peeling methods.
Materials and Methods
The designed and constructed system consists of three main parts: the container, the rotating disk, and the power system, which includes the electric motor. The rotating disk, as the heart of the system, is made from a 1.5 mm thick steel sheet with a diameter of 640 mm. It has been laser-cut with sufficient precision to cut and transfer walnuts. The third part of the system is the power unit, which includes a 3-hp, 1400 rpm electric motor. Power transmission is carried out using a V-shaped belt. In this system, the product is first collected from the designated garden and stored in equally weighted bags. The rotating plate is the most important component of the walnut peeler, essentially the heart of the system. On this plate, there are 12 oval grooves, each 5 mm in diameter and 150 mm in length. One side of each groove is raised, with a depth that can be varied. Increasing the groove depth increases the amount of peel removed and exposes a larger surface of the walnut. The plate is connected to the driven pulley and then to the electric motor via a shaft. In this research, a life cycle assessment was also used to evaluate the impact of various parameters of the walnut peeling system on the environment and its pollution level.
Results and Discussion
The findings from the variance analysis regarding the impact of groove depth and rotation speed on peeling percentage indicate that variations in plate groove depth and electric motor rotation speed during walnut peeling are significant at the 1% level. Furthermore, the impact of changes in the groove depth of the cutting plate on machine performance and the reduction of walnut losses is substantial, showing significance at the 1% probability level. The effect of this factor on the amount of damage to walnuts is significant at the 5% level. By increasing the groove depth from 1.5 to 3 mm and from 3 to 5 mm, changes of 6.99% and 5.12% in walnut skin removal were observed. By reducing the elevation of the groove, the amount of cutting removed from the walnut surface is also reduced, and the peeling process becomes more abrasive. In this case, for proper peeling, the cycle duration and retention time in the machine should be increased. By increasing the rotational speed from 218 to 275 rpm, the momentum and linear velocity increase, resulting in more green shell removal. Conversely, reducing the rotational speed decreases the impact, leaving more green skin on the product. The interaction between rotational speed and groove depth is also significant in the amount of peeled product at the 1% level. The results of the life cycle assessment showed that the human health index has the highest value due to the use of electric power, iron profile (in the system chassis and container), and copper wire in the electric motor armature. Optimizing the system and using clean energy can help improve system efficiency and reduce environmental impact.
Conclusion
Utilizing a walnut peeling machine achieves an impressive 94% efficiency in walnut peeling while ensuring less than 5% damage. The results of the life cycle assessment showed that the use of a walnut peeling machine has less environmental damage than the traditional method and is highly cost-effective.

Abstract Understanding soil deformation dynamics is critical in various fields, such as off-road vehicle mobility, agriculture, and soil mechanics. In particular, evaluating soil-tire interactions is essential for optimizing energy consumption and minimizing the negative effects of soil compaction. This study investigates the effect of soil deformation rates on the pressure-sinkage relationship and energy consumption using a controlled soil bin environment and a bevameter system. The primary objective of the study is to examine how different traffic levels and varying penetration rates influence the energy required to achieve specific sinkage depths. The study employed a completely randomized block design, with each treatment replicated three times to ensure precision and reliability. Quantitative measurements were obtained using a load cell attached to a bevameter, capturing the forces at a sampling frequency of 30 Hz. Results demonstrated a significant influence of both traffic level and penetration velocity on soil resistance and energy consumption. For the larger plate, the pressure required for penetration increased with higher velocities and traffic levels. At the highest velocity (45 mm s^-1) and with 8 passes, the pressure needed for sinkage was maximal. The energy consumption for each scenario was calculated by integrating the area under the force-sinkage curve. The analysis of variance (ANOVA) revealed that the number of wheel passes, plate size, and penetration velocity significantly affected energy consumption. At the highest sinkage depth (60 mm), the energy consumption for the larger plate at 45 mm s^-1 and with 8 passes was nearly double that of the smaller plate. These results emphasize the importance of considering both traffic-induced compaction and velocity when designing off-road vehicles or agricultural machinery that interact with deformable terrains.

Abstract In Iran, more than 50,000 hectares of sunflowers (oil and nuts) are cultivated annually. Conventional grain combine harvesters are not compatible with the unique characteristics of sunflowers, leading to significant grain losses during harvesting. Therefore, it is currently being harvested manually. Manual harvesting increases labor hardships, energy and time consumption, and production costs. In this research, to harvest sunflower seeds, modifications were made on conventional head of a combine harvester (John deer 1055) to allow simultaneous harvesting, threshing, and cleaning of the sunflower seeds. After designing and fabricating the accessory, the improved head in field conditions was evaluated and compared with conventional harvesting methods. The field evaluation of the improved head was based on a randomized complete block design with three replications. The treatments involved three different harvesting methods: 1) using a modified combine head, 2) employing a combine equipped with pan attachment, and 3) manual harvesting. In each of the machine treatments, beating and cleaning units were set up for sunflower harvest. The results showed that there was a significant difference between the treatments concerning machine losses, field capacity, and harvesting costs, all at the 5% significance level. In the modified combine, combine with pans attachment, and manual method, combine losses were 0.72, 4.85, and 6%, and field capacity was 1.2, 1.13, and 0.12 ha h^-1, respectively. The profit-to-cost ratio was 13.97, 13.3, and 3.01, respectively. The grain breakage percentage was 3, 3.3, and 0.56, respectively. According to the results, due to lower losses, appropriate field capacity, and lower harvesting costs, the use of John deer 1055 combine with the modified head is recommended for harvesting of the sunflower.

Abstract Introduction
Innovative technologies, such as smart sprayers, are pivotal catalysts for modernizing the agricultural sector and play an indispensable role in providing food for human consumption. Without the utilization of these technologies and the implementation of proper input management, it is predicted that environmental impacts will worsen in the future. Attaining sustainable production, while implementing programs to ensure food security, presents a considerable challenge for researchers and policymakers worldwide. In this research, the performance of a fixed-rate orchard sprayer was evaluated. Employing various equipment, the sprayer was then upgraded to a variable-rate sprayer, and its performance was reevaluated and compared to the fixed-rate model.
Material and Methods
This research comprehensively evaluated a fixed-rate orchard sprayer and subsequently upgraded it to a variable-rate sprayer for further assessment. The primary components of the developed variable-rate sprayer, consists of an ON-OFF solenoid valve, a digital camera for imaging purposes, an ultrasonic sensor, a flow meter, and a control circuit. The necessary modifications were implemented on a fixed-rate turbine sprayer. The development of the variable-rate sprayer was devided into two distinct phases. The initial phase involved determining the canopy volume and acquiring the necessary information pertaining to the spraying target, specifically the tree. The subsequent phase focused on decision-making and control of the spraying rate, thereby facilitating variable-rate application. Upon laboratory examination of the samples, spectroscopic results were obtained, and the total concentration of the pesticide solution was calculated across different sections of a one-hectare orange orchard. An investigation into the sedimentation of pesticide solution was conducted across different treatments in two spraying modes namely, variable-rate and fixed-rate and at three distinct speeds: low (1.6 km hr^-1), medium (3.2 km hr^-1), and high (4.8 km hr^-1) resulting in six treatments.
Results and Discussion
The comparative analysis of average pesticide deposition on trees revealed a significant difference between the two spraying modes; variable-rate and fixed-rate. All indicators demonstrate that the type of sprayer and the spraying speed significantly influence changes in pesticide deposition across different treatments. However, the interaction effect of the type of sprayer and the speed of spraying did not significantly impact the amount of pesticide deposition on the trees and the total consumption of pesticide per hectare. The results indicated that neither the type of sprayer, nor the speed of spraying, nor their interaction had a significant effect on the spraying quality index. Furthermore, the numerical median diameter and volume median diameter were not significantly different across the treatments.
The maximum pesticide consumption savings in the variable-rate spraying mode was 46%, achieved at a speed of 1.6 km hr^-1. The maximum efficiency was 70% in the variable-rate spraying mode, occurring at a speed of 3.2 km hr^-1. The lowest amount of pesticide deposition on the canopy of trees was observed in the variable-rate spraying method at the speed of 4.8 km hr^-1 (1303 L ha^-1), and the highest amount of deposition occurred in the fixed-rate spraying at the speed of 1.6 km hr^-1 (2121 L ha^-1). The highest amount of pesticide release in the air was also calculated in the fixed-rate spraying mode with a speed of km hr^-1 (241 L ha^-1) and the lowest value was calculated in the variable-rate spraying mode with a speed of 3.2 km hr^-1.
Conclusion
Emerging technologies, such as smart sprayers, play a crucial role in increasing the productivity of the agricultural sector. If these technologies are not utilized, the challenges related to the sustainability of production will increase in the future. One of the critical operations in the production of agricultural products is the spraying phase. In this research, a fixed-rate sprayer was upgraded to a variable-rate sprayer, both sprayers were evaluated, and the results of this evaluation were then used to compare the two spraying systems. The results revealed that because the amount of the pesticide sprayed is controlled in real time by canopy volume detection in the variable-rate sprayer, in the best case (speed 1.6 km hr^-1), it reduced pesticide consumption by 46% and reached 70% efficiency. In all the studied treatments, both the type of sprayer and the speed of spraying significantly affected changes in pesticide deposition. However, the interaction between the type of sprayer and the speed of spraying did not have a significant effect on the amount of pesticide deposition on trees or total pesticide consumption per hectare. There was no significant difference in the coverage percentage of the pesticide deposition on the target in different treatments, and the best spraying quality occurred in variable rate spraying with a speed of 4.8 km hr^-1.
By using a variable-rate sprayer, while saving on the costs of chemical pesticide consumption and spraying, toxic emissions that cause environmental pollution will also be reduced. Future research should focus on developing a variable-rate system based on independent nozzles, allowing for real-time control of each individual nozzle's spraying.

Abstract Introduction
This study investigated the development and evaluation of an automatic feeder control system for sugarcane planters. The primary objective was to address limitations in existing machines and enhance their performance by introducing precise control of cane feeding.
Materials and Methods
The automatic feeder control system was equipped with three types of sensors, including a Load Cell Sensor that directly measures the weight of sugarcane on the feeder table. This feature provides a real-time assessment of cane availability. The Hydraulic Oil Pressure Sensor monitored the pressure within the hydraulic system that drives the feeder mechanism. Variations in pressure served as an indirect measure of the force applied to the cane during the feeding process. The Ultrasonic Distance Sensor employed ultrasonic waves to estimate the distance between the sensor and the sugarcane pile. Nevertheless, some limitations concerning accuracy and response time were identified. A microcontroller served as the central processing unit, receiving sensor data and generating control signals to regulate the feeder mechanism. This allowed for automation and eliminated the need for a manual operator. The performance of the automatic feeder control system was evaluated against a manual control method operated by a human.
Results and Discussion
The evaluation focused on three key aspects: cane spillage, planting quality, and control stability. Cane Spillage: the amount of sugarcane inadvertently dropped during the planting process. Automatic control methods using a load cell and hydraulic oil pressure sensor reduced spillage similarly to manual control, averaging approximately 8.8 t ha^-1. The ultrasonic sensor resulted in significantly lower spillage, achieving 7.4 t ha^-1. However, its limited accuracy and responsiveness led to undesirable gaps between the planted canes. Planting Quality: The implementation of automatic control techniques utilizing load cells and hydraulic oil pressure sensors successfully ensured uniform spacing between planted canes, achieving results comparable to traditional manual methods. Due to its shortcomings, the ultrasonic sensor created gaps between the planted canes, undermining the overall quality of the planting process. Control Stability: The method utilizing hydraulic oil pressure sensors exhibited limitations in maintaining consistent control under varying operational conditions. This stemmed from temperature-dependent changes in oil viscosity, which affected the pressure readings and ultimately the control signal. Based on the evaluation results, the load cell control method emerged as the most favorable option for automatic feeder control. It delivered performance that matches manual control in terms of cane spillage reduction and planting quality, all while eliminating the need for an operator. The hydraulic oil pressure sensor method, although effective in some aspects, presented challenges due to oil viscosity variations. The ultrasonic sensor showed promise for reducing spillage; however, it ultimately fell short due to its inability to accurately and swiftly detect the availability of cane, resulting in gaps between planted canes. A separate assessment was carried out to compare manual cultivation with an automatic control method based on weight measurements using a load cell. This evaluation revealed significant differences (p < 0.01) in billet weight, the number of billets utilized, and one-sided gaps between the two methods. However, no significant difference was observed in terms of two-sided gaps.
Conclusion
This study successfully designed and implemented an automatic feeder control system for sugarcane planters. The load cell control method emerged as the most effective solution, successfully eliminating the need for operators while ensuring high standards of planting quality and efficiency. Additional research could explore advancements in sensor technology and control algorithms to further enhance the performance of automatic feeder control systems.
Acknowledgment
The authors would like to express their gratitude to the Managing Director of Farabi Agro-Industrial Company and its staff, as well as the technical staff of Poya Sazan Sabz Avane Company, who cooperated in the preparation and evaluation stages of the system. Vice Chancellor for Research and Technology of Shahid Chamran University of Ahvaz, Iran: financial support under the special research grant number SCU.AA98.505.

Abstract Introduction
About 30% of the annual losses of agricultural products are caused by pests, diseases, and weeds. Spraying is currently the most common method of their control. At present, various manual and tractor-mounted sprayers are used for spraying. Manual spraying has very low work efficiency and is damaging as the spray might be applied irregularly and consumed by the labor or the product at poisonous levels. Tractor-mounted sprayers are more efficient than manual sprayers and require less labor. However, their use is associated with issues such as compacting the soil or crushing the product. In recent years, Unmanned Aerial Vehicle (UAV) sprayers have been used to spray farms and orchards. UAV spraying can increase the spraying efficiency by more than 60% and reduce the volume of spray used by 20-30%. Based on the capabilities of the UAV sprayer and the limitations of other current spraying methods, the purpose of this research is to evaluate the performance of the UAV sprayer in controlling Brevicoryne brassicae (L.) and compare the results with a turbo liner sprayer.
Materials and Methods
In the present research, the UAV sprayer is studied as a new method of spraying to fight Brevicoryne brassicae (L.). The results were technically and economically evaluated and compared with the control group and that of the turbo liner sprayer (the conventional method of spraying canola in Iran). The experiment was triplicated with a completely randomized design and three treatments of UAV sprayer, turbo liner sprayer, and control (no spraying). Field tests were conducted on the canola crop at the stemming stage where at least 20% of the plants were infected. The measured parameters included drift, spraying quality, field capacity, field efficiency, energy consumption, and spraying efficiency.
Results and Discussion
Based on the results, the spray volume consumed by UAV and turbo liner sprayers was equal to 11.1 and 187.6 liters per hectare, respectively. The particle drift in spraying with UAV sprayer and turbo liner sprayer were 53.3% and 80%, respectively. Moreover, the quality coefficient of UAV and turbo liner sprayers were 1.15 and 1.21, respectively. Therefore, the farm efficiency of the UAV sprayer and turbo liner sprayer was equal to 51.4% and 32.3%, respectively. Based on the results of the analysis of variance, immediately after spraying, there was no statistically significant difference between the average density of pests of the three treatments. However, three, seven, and 14 days after spraying, there was a significant difference between the control treatment and the spraying treatments. The density of pests in the plots sprayed with UAV and turbo liner sprayers was lowered to less than 100 pests per stem, whereas in the control treatment, the density varied between 250-700 pests per stem. A comparison of the average efficiency of the UAV sprayer and turbo liner sprayer with the t-test showed that both sprayers had managed to control the population of pests and 14 days after the spraying, the efficiency of the UAV sprayer was higher than that of the turbo liner sprayer.
Conclusion
- The spray volume consumed by the turbo liner sprayer was 17 times the UAV sprayer.
- The spray drift was about 34% more in spraying with the turbo liner sprayer than the UAV sprayer.
- The field efficiency of the UAV sprayer was 59.1% more than the turbo liner sprayer.
- The energy consumption per hectare of the turbo liner sprayer was 7 times the energy consumption of the UAV sprayer.
- UAV sprayer’s efficiency reached 92.7 % 14 days after spraying.
- UAV sprayer is recommended for controlling Brevicoryne brassicae (L.) due to its high efficiency, low drift, low spray volume and energy consumption, and superior spraying quality.
- To improve the performance of the UAV sprayer for controlling Brevicoryne brassicae (L.), a flight height of 1-1.5 meters from the top of the crop, a flight speed of less than 7 m s^-1, and a maximum spraying speed of 4 m s^-1 are recommended. Additionally, it is possible to prevent the spread of the pest in the stemming stage by spraying the field in an earlier stage.

Abstract Introduction
Due to the increasing need for agricultural products, protection of products against pathogens and preventing them from being wasted is important. Studies on droplet charging systems result in the reduction of chemical usage and an increase in the deposition of droplets on the target. Conventional sprayers used in Iran have numerous disadvantages such as drift, environmental pollution, lack of complete and homogeneous coverage of the spraying surface, phytotoxicity, and crop losses. Therefore, evaluation of new spraying methods and using a variety of electrical sprayers as alternatives to conventional spraying is essential. This study aims to design, construct, and optimize the performance of the electrodynamic head of an atomizer motorized knapsack sprayer, and study the effects of the angle of the target position, spraying distance, and wind speed on the performance of the electrodynamic sprayer.
Materials and Methods
Experiments were performed in an agricultural machinery workshop at The Department of Biosystems Engineering, the University of Kurdistan, Iran, with an atomizer motorized knapsack sprayer equipped with an electrodynamic head. The effect of some factors including wind speed, spraying angle, and spraying distance on deposition, coverage percentage, and uniformity of spraying were investigated. These effects were investigated to determine the uniformity coefficient of total spraying. Design Expert 8.0.6 Trial software was used to design the experiments based on central composite design and to analyze the data. The investigated factors and levels were: the distance of nozzles from the target (at three levels of 2, 4, and 6 m), the angle of the target position (at three levels of 0, 45, and 90 degrees), and wind speed (at three levels of 2.5, 3, and 3.5 m s^-1). Water-sensitive paper cards were used to evaluate the quality of the spraying. The cards were scanned and magnified with an Olympus SZX12 Stereo Microscope equipped with an objective lens of X1 and a total magnification of 7X. The characteristics of droplet size were determined using Mountains Map Trial and Deposit Scan software.
Results and Discussion
The maximum value of the total spraying uniformity coefficient was equal to 1.95 for the spraying angle of 0 degrees, the distance of 6 meters, and the speed of 3.5 meters per second. Meanwhile, the lowest value of the spray uniformity coefficient of 1.18 was obtained for the test conditions of 90 degrees, distance of 2 m, and speed of 2.5 m s^-1, respectively. Based on analysis of variance for the two-factor interactions model (P-value less than 0.0001, explanation coefficient 0.9383, absolute explanation coefficient 0.910, standard deviation 0.0590, and coefficient of variation 3.790%). It can be stated that this model is highly accurate in predicting the uniformity of the total spraying, and the linear components of spraying angle and spraying distance, as well as the interaction of spraying angle × spraying distance and spraying distance × wind speed, significantly affect the uniformity of the total spraying (p<0.05). Nevertheless, the linear component of wind speed and the interaction between wind speed and spraying angle had no significant effect on the changes in the uniformity coefficient of the total spray. According to the variance analysis table (F-values), spraying distance has a far greater effect on the spraying uniformity coefficient than the spraying angle.
It has been observed that the spraying uniformity coefficient will increase by increasing the spraying distance and decreasing the spraying angle. It can also be stated that the linear components of spraying angle and spraying distance, the interaction component of spraying angle × spraying distance, and the square power of the components of spraying distance and wind speed have a significant effect on surface coverage. The values of R², Adj-R², CV, and PRESS for the model adapted to the test data of leaf surface coverage percentage were obtained as 0.9929, 0.9865, 4.87%, and 188.61, respectively.
Among the three input variables, the spraying distance has the greatest effect on the coverage of water-sensitive papers. At larger spraying angles, especially 90 degrees, the coverage decreased with the increasing distance. At spray angle of 90 degrees, by increasing the distance from 2 to 4 m, the spray uniformity coefficient increased from 1.18 at a wind speed of 2.5 m s^-1 to 1.84 at a wind speed of 3.5 m s^-1. However, at smaller spraying angles (for example zero-degree angle), at first, the spraying coverage increases with the increase of the spraying distance from 2 to 3 m and then sharply decreases afterward. According to the contours of spray coverage, in the spray distance range of 4 to 6 m and regardless of wind speed, the spray coverage does not vary with the increase of the spraying angle (p< 0.05). Meanwhile, in the spray distance range of 2 to 4 m, with the increase of the spraying angle, the spraying coverage increases significantly (p<0.05). Overall, increasing the distance between the sprayer and the target decreased the surface coverage on the target, and in electrodynamic spraying, the uniformity of particle deposition on the underside of the target was relatively the same as on the upper side.
Conclusion
To improve the performance of the atomizer motorized knapsack sprayer, an electrodynamic spraying head was designed and built, and its performance was optimized using the response surface method (RSM) with a central composite design. During the research process, the influence of the independent parameters such as the distance between the nozzle and the target, the angle of the target position, and the wind speed on the variables including spraying uniformity, the percentage of the spraying coverage, and the percentage of changes in the total spraying coefficient were discussed and investigated. The results of the research led to the determination of the 3.5 m s^-1 wind speed, 2.5 m sprayer distance, and 90 degrees spraying angle with 0.792 desirability, which were considered as the optimal performance conditions of the electrodynamic spraying head. The results of laboratory validation for optimal conditions show that the uniformity of total spraying indicated by the total relative span factor (RSFT) and the percentage of spraying coverage (Cov) are equal to 1.65 and 28.27%, respectively.

Abstract Machinery traffic is associated with the application of stress onto the soil surface and is the main reason for agricultural soil compaction. Currently, probes are used for studying the stress propagation in soil and measuring soil stress. However, because of the physical presence of a probe, the measured stress may differ from the actual stress, i.e. the stress induced in the soil under machinery traffic in the absence of a probe. Hence, we need to model the soil-stress probe interaction to study the difference in stress caused by the probe under varying loading geometries, loading time, depth, and soil properties to find correction factors for probe-measured stress. This study aims to simulate the soil-stress probe interaction under a moving rigid wheel using finite element method (FEM) to investigate the agreement between the simulated with-probe stress and the experimental measurements and to compare the resulting ratio of with/without probe stress with previous studies. The soil was modeled as an elastic-perfectly plastic material whose properties were calibrated with the simulation of cone penetration and wheel sinkage into the soil. The results showed an average 28% overestimation of FEM-simulated probe stress as compared to the experimental stress measured under the wheel loadings of 600 and 1,200 N. The average simulated ratio of with/without probe stress was found to be 1.22 for the two tests which is significantly smaller than that of plate sinkage loading (1.9). The simulation of wheel speed on soil stress showed a minor increase in stress. The stress over-estimation ratio (i.e. the ratio of with/without probe stress) noticeably increased with depth but increased slightly with speed for depths below 0.2 m.

Abstract Introduction
The world today is facing the issue of population growth, which will result in food shortages. One way to supply food to this growing population is to facilitate the production of agricultural products to meet the growing demand. Medicinal plants are an important product of the agricultural sector. In Iran, manual harvesting reduces the productivity of these crops, and the use of manual harvesting poses challenges related to available manpower. The costs and time required for manual harvesting are additional obstacles. Given the importance of developing medicinal plants, designing and constructing a mechanized machine for harvesting them could improve the harvesting process.
Material and Methods
In designing the machine for harvesting medicinal plants in cultivation rows, different scenarios were examined regarding the position of the machine relative to the tractor. The advantages and disadvantages of each scenario were listed separately, and finally, the continuous placement of tractors, harvesters, and trailers was defined. One of the goals of designing this machine is to perform harvesting operations for two row spacing’s - 80 and 160 cm. To achieve this goal, mechanisms were added to the machine that allow for changing the position of the harvesting head, as well as the cutting height. Moreover, due to the sensitivity of the harvested product to soil contact, the plants should be transferred immediately after cutting. Therefore, a transfer mechanism was designed and built to move the cut products to the trailer. Independent variables, including forward speed at two levels, type of reel in two types, and cutting blade in two types, were considered. Dependent variables also included harvesting efficiency, percentage of damaged plants, and harvesting capacity.
Results and Discussion
The results of variance analysis for different treatments show that the forward speed, type of reel, and cutting blade type have an effect on harvest efficiency. The difference in harvest efficiency is significant at a 1% probability level. A star cutting blade provides higher efficiency than a 40-teeth cutting blade. The rubber reel prevents plants from falling to the ground by creating a closed space in front of the blade. However, the inner parts of the rods reel are empty, and the plant can fall to the ground. Additionally, the plant may get wrapped around the rods, causing a decrease in harvesting efficiency. Another essential parameter when identifying and evaluating a harvesting machine is crop damage. Some plants get crushed and torn due to the impact on metal components. This situation reduces the quality of the harvested product, leading to a decline in the final product's price. The star-cutting blade causes more leaf rupture. In contrast, the teeth in the 40-teeth blade are continuous, making it unlikely for the leaf to get caught between the two teeth. However, with the star blade, the distance between the two blades is large, allowing the plant to get stuck in between and re-cut.
Conclusion
Based on tests conducted for eight different positions of the harvester, it was observed that the G test outperformed the other tests with 85.88% harvesting efficiency, a capacity of 344.8 kg h^-1, and only 1.34% peppermint leaf damage. Therefore, for harvesting similar peppermint products, we recommend using a combination of a star blade, rubber carousel, and a forward speed of 1.2 meters per second. However, new tests should be conducted on other products like lavender and those with strong stems.

Abstract Introduction
In conventional combine harvesters, wheat chaff is typically removed from the end of the machine and deposited on the field surface. Depending on the wheat cultivar, cultivation method, and growing conditions, the amount of chaff produced can range from 0.8 to 1.5 times the amount of grain harvested per hectare (Tavakoli, 2012). On average, this translates to an annual production of approximately 14 million tons of chaff, which is valued at around $240000000 based on regional prices in 2018-2019 ($1000 per kilogram). If collected, these chaff residues could be used as animal feed for livestock. Additionally, the long stems protruding from the back of conventional combine harvesters can interfere with subsequent cultivation efforts. Chaff combine harvesters have a similar structure to conventional machines, but feature a modified end that includes a tank and blower for collecting and depositing crushed chaff. Apart from the threshing unit, all other components of the harvester remain unchanged.
Materials and Methods
This study was conducted in 2019 in dryland wheat fields to determine the performance of Chaff combine harvesters in Kurdistan province. The study used 15 combine harvesters, including John Deere models equipped with chaff threshers from Shiraz, Bookan, and Hamedan, as well as the Hamedan Barzegar specific chaff collector combine. These combines were evaluated and compared based on natural losses, head and chaff storage losses, field capacity, purity percentage, and yield in field conditions in Kurdistan province. The total number of combines evaluated was 15, using a completely randomized design. Among these, 33% belonged to Shiraz company (5 samples), 33% to Bookan (5 samples), 20% to Hamedan (3 samples), and 14% to Hamedan Barzegar (2 samples). Sampling included measurement of natural losses, header losses, threshing tank losses (losses of the threshing unit, separating unit, and cleaning unit), and quality losses (broken grains and impurities) in the combine tank.
Results and Discussion
The results showed that the average yield, natural loss, and combine loss were 1,698.14 kg.ha^-1, 2.39%, and 4.92%, respectively. In terms of the loss rates in different parts of the combine, 43.49% was related to the chaff storage of the combine, and 56.50% was related to the combine head.
The natural loss rate in this province was 2.39%. The total combine loss was 5.18%, with 40.44% of that related to chaff storage and the rest related to the combine head. The results also showed a significant difference between the treatments in terms of field capacity, chaff storage loss, and purity percentage at a probability level of 5%.
The total loss of the Hamedan Barzegar combine was 6.67%, which was higher than the other combines. The chaff storage loss of the Shiraz, Bookan, Hamedan, and Hamedan Barzegar combines were 0.87%, 2.64%, 0.78%, and 4.28%, respectively, showing a significant difference at a 5% level. There was also a significant difference between the treatments in terms of total grain loss.
Based on these results, it is recommended to use the Hamedan, Bookan, Shiraz, and Hamedan Barzegar combines, with total losses of 4.33%, 4.33%, 4.52%, and 6.56%, respectively.
Conclusion
The average purity of harvested grains was 96.62%, and there was no significant difference between the combine harvesters in this regard.
There was a significant difference between the combines in terms of field capacity at a probability level of 5%. The field capacity of the Bookan, Hamedan Barzegar, Hamedan, and Shiraz combine harvesters were 0.83, 0.87, 0.83, and 0.73 hectares per hour, respectively.
In Kurdistan province, the average grain combine loss in dryland wheat harvesting with chaff combine harvesters was 4.92%, which is higher than in other provinces.
The loss in the chaff tank of the Shiraz, Bookan, Hamedan, and Hamedan Barzegar combine harvesters was 0.87%, 2.64%, 0.78%, and 4.28%, respectively. Regardless of head losses, the loss in the Hamedan combine was less than other combine harvesters.
The total losses of the Hamedan Barzegar, Bookan, Shiraz, and Hamedan combine harvesters were 6.56%, 4.32%, 4.52%, and 4.30%, respectively, with the Hamedan Barzegar and Hamedan combine harvesters having the highest and lowest losses, respectively.
Based on the results obtained from this study, using the Hamedan combine is recommended in the dryland conditions of Kurdistan due to its low losses, high purity, and field capacity.
Acknowledgement
Thanks to the Agricultural Jihad Organization of Kurdistan Province, specifically the deputy of the Plant Production and Mechanized Technologies Department, for their assistance and cooperation in the implementation of the project.

Abstract Introduction
Cotton, as one of the most widely used products in various industries, has always been considered by leading countries in agriculture. The applications of this plant range from the food industry to the military industry, as well as the textile and animal nutrition industry. It is predicted that by 2025, the area under cotton cultivation in the world will reach more than 33 million hectares (FAO, 2017). Based on the growing population, it is necessary to use machines in industries and other sectors to accelerate production and increase efficiency. Cotton is no exception to this rule. The use of a machine can play an effective role in reducing harvest costs and decreasing losses from frost and early fall rainfall by enabling timely harvesting.
Material and Methods
Armaghan cultivar is an early-maturing cotton cultivar with high yield potential and good compatibility, introduced for conventional and secondary crops in Golestan, North Khorasan, Ardabil, and the central regions of Iran. The early maturity of this cultivar provides the possibility of cotton cultivation after wheat harvest in different regions of Iran. It reduces pests and diseases through the escape mechanism and completes the growth period in delayed planting. In this research, two types of picker machines were compared. One of the harvesting machines used in this study is a two-row self-propelled spindle picker machine, and the other picking machine is a two-row tractor semi-mounted dentate picker. Before harvesting with a machine, it is necessary to use a defoliator. This allows for seed cotton harvest with less trash and more cleanliness. About ten to fifteen days after spraying the defoliator, the leafless plants are ready for machine harvesting. In this study, the number of leaves was counted before spraying and before harvest, and the percentage of defoliation in each treatment was calculated and evaluated. The harvesting efficiency of machines, machine losses, and fiber qualities for each harvester was measured.
Results and Discussions
The results showed that the type of machine has a significant effect on plant residues and machine performance. However, the loss on the ground is not affected by the type of machine and remains almost the same for both machines. The mean comparisons revealed that the spindle harvesting machine leaves more than twice the amount of residues on the plant compared to the dentate harvesting machine. In terms of fiber quality, no significant difference was observed in any of the qualitative properties, and both machines perform at the same level.
Conclusion
The results of this research on the functional characteristics of picker machines and the cultivar and field conditions demonstrate that a higher percentage of leaves on the plant yields better performance from dentate picker machines compared to spindle pickers. Spindle pickers are sensitive to leaves due to the teeth on their needles, causing reduced efficiency in such fields. In contrast, dentate picker machines work well and perform better under these conditions. Based on this study, the dentate harvesting machine is more suitable than the spindle picker machine for harvesting Armaghan cotton cultivars.

Abstract Introduction
Sugarcane is one of the strategic products of Khuzestan province, which is cultivated in 10 active agro-industrial sites and covers an area of about 110,000 hectares of irrigated farms in the province. Sugarcane harvesting, like most crops, is done by special sugarcane harvesters. Due to the life of machines and also the amount of heavy machine operations in each season of sugarcane harvest, the loss is inevitable. On the other hand, in Khuzestan province, due to lack of studies, there is little information in this area. Therefore, the aim of this study is to investigate the extent of losses during sugarcane harvesting operations, taking into account factors such as cultivars, age of sugarcane, and reaping speed of the Astaf 7000 model. The study will be conducted at the sugarcane agro-industrial site of Dehkhoda in 2021.
Materials and Methods
The experiment was conducted as a factorial split-plot design based on randomized complete blocks (RCBD) with three replications. The first factor included four levels of cultivars (IRC-12, CP48-103, CP 73-21, and CP69-1062), the second factor included three levels of harvest age (plant, Ratoon 1, Ratoon 2), and the third factor included three levels of speed (3, 5, and 7 km h^-1). Sampling was carried out under the same and constant conditions with respect to soil moisture content, harvester operator, harvester characteristics, harvester settings, and crop density in each field.
Results and Discussion
The results of analysis of variance of the data obtained from measuring sugarcane losses showed that the effect of cultivar on yield, full-length sugarcane, chopped sugarcane and splinter sugarcane had a significant effect at a probability level of one percent. The effect of age had a significant effect on yield, full-length sugarcane, chopped sugarcane with a probability level of one percent, but had no significant effect on the amount of splinter sugarcane. The interaction between cultivar and age had a significant effect on yield, chopped sugarcane, and full-length sugarcane with a probability level of one percent and on splinter sugarcane with a probability level of five percent. The effect of machine speed had a significant effect on full-length sugarcane, chopped sugarcane and splinter sugarcane with a probability level of one percent, but had no significant effect on yield. The interaction of cultivar and machine speed had a significant effect on yield, full-length sugarcane, chopped sugarcane and splinter sugarcane with a probability level of one percent. The interaction effect of age and machine speed on yield had a significant effect on full-length sugarcane and splinter sugarcane with a probability level of one percent and on the amount of splinter sugarcane with a probability level of five but had no significant effect on yield. Also, the interaction of cultivar, age and machine speed had a significant effect on yield, full-length sugarcane and chopped sugarcane with a probability level of one percent, but had no significant effect on the amount of splinter sugarcane. The results showed that the highest yield in CP69-1062 variety was observed in the plant farm with average machine speed (144.33 tons per hectare). Also, the highest amount of sugarcane losses in cultivar CP48-103 in Raton II and with 7 km h^-1 machine speed (3.32 tons per hectare), the highest amount of chopped sugarcane losses in cultivar CP48-103 in plant farm and with average speed (1.78 tons per hectare) was observed. According to the results under the interaction of cultivar and device speed, the highest amount of sugarcane losses in CP69-1062 cultivar and high speed (0.314 tons per hectare) as well as IRC-12 cultivar and high speed (0.308 tons in Hectares), and under the interaction of farm age and speed of the harvester, the highest amount of sugarcane losses was observed in Ratoon farm and the high speed of the harvester (0.300 tons per hectare).
Conclusion
Therefore, in order to reduce the amount of losses in sugarcane fields, it is recommended to use resistant and somewhat later cultivars for cultivation, because early cultivars are more fragile during harvest due to stem fragility and the rate of losses increases. Also, Harvester speed optimization reduces the amount of losses, and due to the increase in the rate of losses in reclaimed farms, it is recommended to create more resistant stem tissue by proper plant nutrition and more care to reduce the rate of losses in ratoon farms.

Abstract Introduction
Peanut (Arachis hypogaea L.) is an annual plant of the legume genus that is cultivated in 109 countries due to its high-quality oil and seed protein. In Iran, this crop is cultivated on an area of 3000 hectares, with an average yield of 4 tons per hectare. Threshing performance significantly affects seed loss and physical damage, including cracking and crushing of seeds during harvest. Therefore, over the last century, extensive research has been conducted on different types of threshing methods, as well as the design and development of various threshing machines.
Research on seed crops such as cereals and seeds suggest that factors such as the rotational speed of the thresher, threshing-concave distance, feeding rate, and shape of threshing teeth play a crucial role in determining the threshing efficiency and quality of the threshed seeds. Although limited research has been conducted on peanut threshing, there are currently no combine-machines available for this crop on global markets. Therefore, this study aims to investigate several working parameters of an experimental peanut thresher, including the effect of sieve angle, sieve range of movement, and suction speed on the separation unit.
Materials and Methods
The relevant experiments were conducted in the Parsabad Moghan region of Ardabil province (latitude 39.65 North, longitude 47.91 East). To conduct the experiments and separate the seeds from the pods, we used a peanut threshing machine cultivar Nc2, which is commonly cultivated under agricultural conditions in Ardabil and Gilan Agricultural Research Centers.
To achieve the aims of this research, we investigated several effective parameters in the performance of the machine, including sieve angle, sieve movement range, and fan suction speed, to obtain the best settings for maximum threshing performance and separation efficiency. It is worth noting that the average seed weight per kilogram of peanut plant was between 300-400 grams, and the moisture content of the seeds in the tested cultivar was 45%. Before using the machine, workers must first dig up the plants and place them on the ground in a coupe, after which another worker must feed the plants into the machine through the feeder.
Results and Discussion
The study found that changes in sieve angle, sieve movement range, and suction speed significantly affect the separation efficiency and peanut loss rate at a 1% significance level. Increasing the sieving angle leads to a higher speed of material movement on the sieve, which results in insufficient time for separating straw from the seed. Similarly, increasing the sieve movement range causes a rapid decrease in cleaning efficiency. To achieve better straw-seed separation, it is necessary to apply impact shocks to the products located on the sieve within a short period. However, as the range of movement increases, the time interval between impact shocks also increases, which disrupts the straw's separation from the seed.
The study found that increasing the sieve range and suction speed leads to a higher rate of peanut loss. This is due to the fact that when the suction speed and sieve movement range are increased, the product spends less time on the sieve, which results in insufficient time for proper separation. Additionally, high speed may exceed the limit of peanut seed and cause it to move out of the machine with the straw. Increasing the sieve movement range leads to a more uniform movement of straw and seed on the sieve; however, achieving better separation of straw from the sieve requires dynamic shocks and sudden acceleration, which decreases as the sieve movement range increases. The optimal farm capacity and material capacity were achieved with a 5-degree slope at 0.55 hectares per hour and 509 kilograms per hectare, respectively, using a sieve range of 3.5 centimeters and a fan suction speed of 8 meters per second.
Conclusion
The study concluded that the sieve movement range has the most significant impact on cleaning efficiency, while the sieve angle has the least effect. Similarly, the sieve movement range has the most significant influence on the rate of peanut loss, while the sieve angle has the least effect.