Majid Davoodi; Saeid Minaei; Ahmad Sharifi
Abstract
This research includes the design, manufacturing, and evaluation of a live mulch planter unit. In order to address the problems of using agricultural machinery in performing live mulch planting in the furrows or simultaneously with the main crop, a prototype planting unit was designed. In this planter, ...
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This research includes the design, manufacturing, and evaluation of a live mulch planter unit. In order to address the problems of using agricultural machinery in performing live mulch planting in the furrows or simultaneously with the main crop, a prototype planting unit was designed. In this planter, a seed-drop plate was used to convey the seeds from the metering device to the ground. The result of this project was a prototype of a planter with the ability to plant 19.6 to 163.2 grams per minute of live mulch (hairy vetch) with a tolerance of 0.54 grams along the entire width of a 75 cm furrow. Laboratory and field experiments were conducted to evaluate its performance in actual field conditions, based on planting accuracy and field efficiency. The Laboratory test was performed according to ASAE S341.2 DEC92 standard for Grain Drill evaluation. Results of the initial evaluation of the planter showed that changing the rotational speed of the metering device significantly affected seed output on the drop plate in terms of seeding rate. The position of the outlets did not differ significantly in terms of seed damage. Increasing rotational speed of the metering device significantly increased the tendency of metering mechanism to damage seeds. Increasing rotational speed of the metering device significantly decreased index of non-uniformity in all outlets.Results of the initial evaluation of the planter showed that changing the rotational speed of the metering device significantly affected seed output on the drop plate in terms of seeding rate. The position of the outlets did not differ significantly in terms of seed damage. Increasing rotational speed of the metering device significantly increased the tendency of metering mechanism to damage seeds. Increasing rotational speed of the metering device significantly decreased index of non-uniformity in all outlets.
Mohammad Rahmatian; Mohammad Amin Nematollahi; Reza Yeganeh; Ahmad Sharifi Malvajerdi
Abstract
Nowadays, tillage and related topics are of great importance to researchers and farmers. One of these issues is the draft force, which is influenced by many factors. Knowing the approximate amount of this force helps, for example, to use suitable machines and tools on the farm. The purpose of this study ...
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Nowadays, tillage and related topics are of great importance to researchers and farmers. One of these issues is the draft force, which is influenced by many factors. Knowing the approximate amount of this force helps, for example, to use suitable machines and tools on the farm. The purpose of this study was to use the results of shear vane and cone penetration tests to provide a model for predicting the draft force of chisel plow without measuring soil physical and mechanical parameters. For this purpose, four farms were seleced and cone index and shear van test were performed on each farm. Also, draft force of chisel plow was obtained in each farm considering the variables of forward speed (3, 5, 7 and 9 km.h-1) and tillage depth (15, 20, 25 and 30 cm). The experiments were performed based on a split plot experiment and on a completely randomized block design with three replications. The results showed that with increasing the penetration depth from 15 to 30 cm, shear strength of soil and cone index increased by 36.62% to 48.21% and 23.60% to 38.86%, respectively. With increasing forward speed and tillage depth, the draft force increased by about 30.16% and 25.32%, respectively. With increasing soil moisture, the amount of draft force decreased by 47.83%. Also, with increasing cone index and shear strength of soil, the draft force of chisel plow increased. According to the relationship between the mentioned variables with draft force, a model with response surface methodology and historical data design was obtained. In this model, draft force was considered as a dependent variable and forward speed, tillage depth, cone index and soil shear strength were considered as independent variables. The coefficient of determination (R2), root mean square error (RMSE) and mean relative deviation modulus (MRDM) for this model were 0.97, 0.49 kN and 2.34%, respectively, indicating high accuracy of the model for predicting draft force.
Payam Farhadi; Abdollah Golmohammadi; Ahmad Sharifi-Malvajerdi; Gholamhossein Shahgholi
Abstract
In this study, a single tire tester was used to study the effects of vertical load, inflation pressure and moisture content on tire rolling resistance in a soil bin. A Goodyear 12.4-28, 6 ply tractor drive tire was employed and the soil texture was a clay loam. The experimental design was a completely ...
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In this study, a single tire tester was used to study the effects of vertical load, inflation pressure and moisture content on tire rolling resistance in a soil bin. A Goodyear 12.4-28, 6 ply tractor drive tire was employed and the soil texture was a clay loam. The experimental design was a completely randomized with factorial layout at three replications. A multivariate regression model was obtained with the correlation coefficient of R2=0.85 to predict the tire rolling resistance based on vertical load, inflation pressure, and moisture content. A multilayer feed-forward ANN (artificial neural network) with standard BP (back propagation) algorithm and LM (Levenberg-Marquardt) training function by using of two hidden layer in the network architecture was employed. RMSE (root mean squared error) and R2 was used as modeling performance criteria. Tire inflation pressure was identified as the controller parameter of tire rolling resistance at low moisture content and also moisture content was the most effective parameter on changing of rolling resistance in regression model. Also the obtained R2=0.977 from ANN model showed that ANN data were more close to actual data than the regression model.
Payam Farhadi; Abdollah Golmohammadi; Ahmad Sharifi-Malvajerdi; Gholamhossein Shahgholi
Abstract
One of the most important issues in agricultural machinery section is tyre - soil interactions. In this study, a single wheel tester was used to follow experiments in controlled conditions in a soil bin. A Goodyear 12.4-28, 6 ply tractor drive tyre was operated at three vertical loads of 6, 9 and 12 ...
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One of the most important issues in agricultural machinery section is tyre - soil interactions. In this study, a single wheel tester was used to follow experiments in controlled conditions in a soil bin. A Goodyear 12.4-28, 6 ply tractor drive tyre was operated at three vertical loads of 6, 9 and 12 kN, three inflation pressures of 80, 120 and 160 kPa and three moisture content of soil: 11.20, 14.86 and 18.68 % d.b to investigate the effect of the variables on these parameters: contact area, contact pressure, compaction, and soil apparent electrical conductivity. It was found that medium contact pressure had a direct relation with vertical load, inflation pressure and moisture content. A regression model with R-square of 0.946 was achieved to predict contact pressure. Soil electrical conductivity changes was predicted with acceptable determination coefficient of 0.850 by using of vertical load, inflation pressure and moisture content. Determination coefficient magnitude for models to predict resistance to soil penetration (cone index) using soil apparent electrical conductivity decreased when moisture content was increased. The vertical load and inflation pressure were found two factors controlling the soil apparent electrical conductivity changes in low and high moisture content, respectively. Error percentage in using soil apparent electrical conductivity parameter to estimate the penetration resistance increased with increasing moisture content.
Adel Vahedi; M. Younasi-Alamouti; Ahmad Sharifi Malvajerdi
Abstract
Rice with the cultivation area of more than 565 thousand hectares and production amount of 2.45 million tons is the second most important crop after wheat in Iran. Most of cultivated area is also located in Mazandaran and Guilan province. It is clear that reaching to self-sufficiency in rice production ...
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Rice with the cultivation area of more than 565 thousand hectares and production amount of 2.45 million tons is the second most important crop after wheat in Iran. Most of cultivated area is also located in Mazandaran and Guilan province. It is clear that reaching to self-sufficiency in rice production is not possible without assessment of current status of rice mechanization. Therefore present study was conducted to determine current status of rice mechanization and propose needed solutions to improve it. Data were gathered by completing questionnaire and by reviewing the literature and field surveying. In view of information obtaeined; degree of mechanization, level of mechanization, capacity of mechanization, economic efficiency of mechanization, field efficiency of machine, potential ability of machine, working hours and days and productivity coefficient of machine were calculated. The results showed that degree of mechanization of primary tillage and secondary tillage was 99.7 and 99.3%, planting operation with transplanter was 22.69% and harvesting operation with mower and combine was 72.8 %. The lowest degree of mechanization of rice production was obtained for mechanical weeding with the value of 8%. The level of mechanization was calculated 2.63 hp/ha. Mean economic efficiency of mechanization and capacity of mechanization of rice was found to be 1.87 ton/ha and 235 hp.hr/ha, respectively.
