Design and Construction
A. Sadin; M. H. Aghkhani; M. A. Ebrahimi-Nik; J. Baradaran Motie
Abstract
IntroductionPlanting 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, ...
Read More
IntroductionPlanting 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 MethodsConventional 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 DiscussionThe 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.ConclusionGiven 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.
The relationship between machine and soil
M. Akbari; I. Hazbawi; M. Jafarian
Abstract
IntroductionTillage 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 ...
Read More
IntroductionTillage 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 MethodsThis 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 DiscussionModeling 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.ConclusionThis 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.AcknowledgmentThe authors gratefully acknowledge the financial support provided by the University of Lorestan.
M. Rahmatian; S. H. Karparvarfard; M. A. Nematollahi; A. Sharifi Malvajerdi
Abstract
All over the world, farmers choose different implements for tillage, which depend on crop type, soil type, the amount of plant residue from the previous crop, etc. Tillage implement selection is also affected by the availability of implements, power consumption, labor costs, and fund. In this research, ...
Read More
All over the world, farmers choose different implements for tillage, which depend on crop type, soil type, the amount of plant residue from the previous crop, etc. Tillage implement selection is also affected by the availability of implements, power consumption, labor costs, and fund. In this research, the draft force, soil disturbance area, soil cone index, and fuel consumption were considered. The effects of rake angle, forward speed, and soil moisture content on the above-mentioned parameters were investigated. In this research, a comparison between the performance of a Fiber Reinforced Polymer (FRP) composite blade and a conventional steel blade was carried out. Tests were based on the split-split plot in a completely randomized design. The factors of soil moisture content, rake angle, and forward speed were included in three levels. Three levels for the soil moisture content (9.3, 13, 16.7 %), rake angle (20°, 30°, 40°), and forward speed (3, 5, 7 km.h-1), were considered. The FRP composite blade (on average in the desired range for variables) has reduced the draft force, fuel consumption, and soil cone index, 14.97%, 16.63%, and 35.08%, respectively, than the steel blade. Also, the soil disturbance area created by the FRP composite blade was 4.93% higher than the steel blade. Based on the results of this study, it is clear that the FRP composite blade has better performance rather than the conventional steel blade for the aforementioned test variables. The FRP composite is inexpensive than the steel, this leads to remarkable save money in the production of the FRP composite blade used in the chisel and combined tillage tools that is economical for the farmer and manufacturer.
Design and Construction
A. Rezahosseini; K. Jafari Naeimi; H. Mortezapour
Abstract
Introduction Harvesting is one of the most difficult steps in cabbage production that is usually a costly intensive operation. Cabbage harvesting is often done by human labors in Iran. According to customs administration’s statistics, more than 54000 tons of cabbages have been exported from Iran ...
Read More
Introduction Harvesting is one of the most difficult steps in cabbage production that is usually a costly intensive operation. Cabbage harvesting is often done by human labors in Iran. According to customs administration’s statistics, more than 54000 tons of cabbages have been exported from Iran in 2015. Development of cabbage harvesting industry is necessary, because of the large cultivation area and the short available harvesting time. So far, a few studies have been done on cabbage mechanized harvesting in Iran. The harvesting machines can reduce harvesting time to one-eighth in comparison with manual harvesting. Design and manufacturing of a harvester unit suitable for small cabbage farms in Iran were conducted in the present study. So the paper was aimed to investigate the performance of the harvester at the different forward velocities, attack angles and distances between the plants. Materials and Methods The proposed machine consists of two major units; the soil looser and the unit for pulling out, crops from the soil. In this machine, the blades loose the soil around the cabbage root after penetrating into the soil. Next, cabbage is pulled out from the soil by puller belts. The belts move contrary to forward speed direction and take crop to the backward of the machine. Mechanical and physical properties of the cabbages should be measured, because the harvester is directly in touch with the crop. These properties are firstly measured and then selection of the different components and machine manufacturing are done. Two narrow legs (tillage tools) equipped with one-side blade with attack angles of 20 and 25 degrees are used for losing the soil around the cabbage’s root. The force exerted on the blade was 5.47 kN. Finally, the harvesting force is estimated to be 164.8 N by using mechanical and physical properties of the cabbages. Experiments were conducted at the different forward velocity levels (2, 3.5 and 5 km h-1), attack angle of the blades at three levels (20, 25 and 30 degree) and the distance between the crops in two levels (40 and 60 cm) in a completely randomized design with three replications. Results and Discussion The analysis of variance of the effect of different parameters on the harvested crop numbers showed, that the effects of forward velocity and attack angle on the number of harvested crops were significant in 5 percent probability. But distance between crops did not have significant effect on the number of harvested crops. Also the effects of interaction between forward velocity and attack angle, forward velocity and distance between crops, attack angle and distance between crops on the number of harvested crops were significant in 5 percent probability. According to the results, the number of harvested crops and machine performance were decreased by increasing forward velocity. Moreover, designed machine had the best performance (80 percent) at an attack angle of 25 degrees and forward velocity of 2 km h-1. Conclusion The results showed, with increasing the forward speed from 2 to 5 km h-1 the harvest success decreased by 20 to 25 percent. Also, the harvesting quality did not change at the different distances between the plants. The highest machine capacity was more than 5300 plants per hour, which was observed at the forward velocity of 3.5 km h-1 and the attack angle of 25 degrees.
Design and Construction
M. A. Zamani Dehyaghoubi; K. Jafari Naeimi; M. Shamsi; H. Maghsoudi
Abstract
Introduction It is common to use rod weeders for onion harvesting according to their prevention of root blocking in front of the machine and separation of onion bulbs from soil by shaking. Chesson et al., (1977), used a rod weeder for manufacturing an onion harvester. This machine had a rectangular rotor ...
Read More
Introduction It is common to use rod weeders for onion harvesting according to their prevention of root blocking in front of the machine and separation of onion bulbs from soil by shaking. Chesson et al., (1977), used a rod weeder for manufacturing an onion harvester. This machine had a rectangular rotor axis with 25mm×25mm cross section. The rotor power was provided by a hydro-motor. An investigation into onion losses during the harvesting operation showed that the majority of crop damages have been occurred due to the collision of rods with onion bulbs. Therefore, the objective of this study is to design and evaluate an onion harvester based on rod weeders with the capability of crop harvesting with minimum damage. Materials and Methods The main components of the examined onion harvester are chassis, furrower, and power transmission system and excrescence axes. Rectangular 100mm×100mm and 40mm×80mm profiles with 4mm profile thickness are used to fabricate the chassis. The furrowers were installed on each side of the chassis as the first parts of the harvester that comes into contact with the soil. Power transmission system provided rotation of two axes from both sides of the machine due to the lack of space for working of two chains on the one side. Therefore, a gearbox having one input shaft and two output shafts was selected for the machine. The gearbox output shafts turn the rotors with a reduction ratio of 1 to 3.5. The rotary motion of the excrescence axes cuts and moves the soil located under the onions bulbs upward and finally the onion bulbs are placed on the soil surface. Therefore, excrescence axes can be considered as the main part of the onion harvester. The excrescence shape of the axes were created by star wheels. Star wheels had a hole with a square section in center (30mm×30mm), for installing them on their shaft. Choosing this kind of the connection, dose not let star wheels to move freely. Also to limit the lateral movement of the star wheels on axis, metallic spacers were used between the adjacent pairs of them. To evaluate the machine performance three variable factors were defined: working depth (20 and 26 cm), forward speed (3, 4.5 and 6 km h-1) and rotational speed of the excrescence axes (150, 220 and 290 rpm). The conducted experiments were analyzed in a complete randomized design with three replications. Results and Discussion The analysis of variance showed that the working depth and forward velocity of axis had significant effect (in 5% level) on the success rate of onion harvester. Also the interaction between depth and forward velocity and the interaction between rotational speed of axes and forward speed were significant. The interaction between depth and rotational speed of axes and the interaction between depth, rotational speed of axes and forward speed were not significant. Evaluation of the interaction between depth and forward velocity showed that the most success rate of onion harvesting was in 20 cm depth and forward velocity equal to 3 and 4.5 km h-1. The least success was gained in 26 cm depth with 4.5 and 6 km h-1 forward speed. Evaluation of the interaction between rotational speed of axes and forward speed showed that the most success in the onion harvesting was occurred with a machine having 3 km h-1 forward velocity and 150 rpm rotational speed and also 4.5 km h-1 forward velocity and 220 rpm rotational speed. Conclusion The success rate of the onion harvesting decreased by increasing the working depth of the machine and axes distance to the onion bulbs. Also with excessive forward velocity the success rate of onion harvesting decreased because of difficulties in controlling the tractor guidance in straight line. The best performance of this onion harvesting machine was in 20 cm depth, 4.5 km h-1 forward velocity and 220 rpm axes rotational speed. Adjusting the machine working parameters according to these values, the ratio of the linear speed of the star wheel tips to the forward velocity of the machine (kinematic index) was equal to 0.82.
Design and Construction
I. Ahmadi
Abstract
IntroductionMeasurement of the draft force exerted from agricultural machineries to the tractor and the calculation of the implement power requirements is important for agriculturalists in terms of machine design and tractor-machine matching . Therefore, studies about this issue have been started from ...
Read More
IntroductionMeasurement of the draft force exerted from agricultural machineries to the tractor and the calculation of the implement power requirements is important for agriculturalists in terms of machine design and tractor-machine matching . Therefore, studies about this issue have been started from the 1950’s. Zoerbet al.,(1983) claimed that the first dynamometers have been made of spring and in reality, users had difficulties reading these dynamometers gauge due to the quick variations of the gauge pointer. Therefore the second stage was the development of the hydraulic-type dynamometers in which the oil pressure inside the hydraulic cylinder-piston set installed between machine and tractor that can be readable with a bourdontube gauge was considered as its indicator. From the first years of the 1960’s development of the strain-gauge pull-type dynamometers started. In this study, design, fabrication and evaluation of a pull-type tractor dynamometer is considered that can be used to measure and store tractor forward velocity, and horizontal component of draft force exerted from wheel-type towed implements to the tractor. Therefore, drawbar power needed to pull the machine through the soil can be calculated. This dynamometer can also be utilized to measure three-point-hitch implement’s draft force and power requirements in condition that the RNAM (1983) method was used. In addition to measure the tractor velocity with a GPS receiver instead of a fifth wheel, the other particular issue about this dynamometer is that a remote controller is used to order data acquisition commands such as starting, ending, pausing and time zeroing in the process of data gathering. Materials and MethodsIn this study an S-type strain gauge load cell (model: SS300) and a GPS receiver (model: Micro GPS antenna AGM-10 + NEO-6-M-0-001 ublox AG board) were utilized to measure the draft force and forward velocity, respectively. To calibrate the load cell sensor, in an iron material selling store, the load cell was placed between an external force with a known value and roof-type load lifter by steel cables, and external loads with the value of 1-5 ton applied to the load cell in ascending and descending order. In each loading stage, the system and measuring apparatus outputs were booked. After drawing the x-y scatter chart of paired values (system output, measuring apparatus output), regression equation between these two variables were obtained that can be utilized to calibrate this part of the system. Above-mentioned method was used to calibrate the velocity measuring part of the dynamometer with a difference that real velocity was used instead of external load and velocity output was used instead of the load cell output. After performing the calibration of the system, the developed dynamometer was utilized to measure the draft force and power requirements of a three-point-hitch moldboard plow using the RNAM method. Finally, the obtained results were compared with the other researcher’s results, and the ASAE prediction of the draft force of a moldboard plow.Results and DiscussionAccording to the results of this study, the estimated equation and its coefficient of determination for the calibration of the load cell sensor were , and respectively, and the estimated equation and its coefficient of determination for the calibration of the velocity were , and respectively. Moreover, according to the results of the field tests, draft force and the power requirements of a three-bottom moldboard plow in a silty clay loam soil with the forward velocity of was measured to be , and , respectively, that were in agreement with other studies. Furthermore, the draft force results of this study, and other studies were in the range of of the which is the moldboard plow draft prediction according to the ASAE standard.ConclusionsThis study suggests that with the aid of the RNAM method, and the developed dynamometer, the draft force and power requirements of the tillage implements can be calculated. These results can further be utilized to match the implements with the tractor or to design new tillage implements.
Design and Construction
M. Khosravi; M. H. Abbaspour-Fard; M. H. Aghkhani
Abstract
The majority of existing tractors in Iran are not equipped with any tools to measure and display slip and ground speed. This is mainly due to the lack of national standards for measuring tools and instruments of tractors. In current research, an interchangeable system for two wheel drive tractors has ...
Read More
The majority of existing tractors in Iran are not equipped with any tools to measure and display slip and ground speed. This is mainly due to the lack of national standards for measuring tools and instruments of tractors. In current research, an interchangeable system for two wheel drive tractors has been designed. Furthermore, it has been assessed after construction. To measure actual and theoretical ground speed, four rotary encoders for sensing the rotation of front and rear wheels have been utilized. Slip and ground speed were measured by means of software which has been developed in an ATmega16PU microprocessor. The measured slip and speed are digitally displayed on tractor dashboard. To evaluate the performance of the system, the measured values of ground speed and slip were compared with their calculated values obtained from conventional method. The Micro-controller has been programmed in such a way that the effect of front wheel sliding on slip is eliminated. In all evaluation conditions (in field and on asphalt), the maximum difference between system measurements for slip and speed and calculated slip and speed via conventional method was 2.4% and 0.2 km h-1, respectively. With slight alteration this system can be fitted on any kind of exiting two wheel drive tractors in the country.
