The relationship between machine and soil
M. Naderi-Boldaji; H. Azimi-Nejadian; M. Bahrami
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 ...
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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.
The relationship between machine and soil
B. Golanbari; A. Mardani; A. Hosainpour; H. Taghavifar
Abstract
Due to the numerous variables that may influence the soil-machine interaction systems, predicting the mechanical response of soil interacting with off-road traction equipment is challenging. In this study, deep neural networks (DNNs) are chosen as a potential solution for explaining the varying soil ...
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Due to the numerous variables that may influence the soil-machine interaction systems, predicting the mechanical response of soil interacting with off-road traction equipment is challenging. In this study, deep neural networks (DNNs) are chosen as a potential solution for explaining the varying soil sinkage rates because of their ability to model complex, multivariate, and dynamic systems. Plate sinkage tests were carried out using a Bevameter in a fixed-type soil bin with a 24 m length, 2 m width, and 1 m depth. Experimental tests were conducted at three sinkage rates for two plate sizes, with a soil water content of 10%. The provided empirical data on the soil pressure-sinkage relationship served as the basis for an algorithm capable of discerning the soil-machine interaction. From the iterative process, it was determined that a DNN, specifically a feed-forward back-propagation DNN with three hidden layers, is the optimal choice. The optimized DNN architecture is structured as 3-8-15-10-1, as determined by the Grey Wolf Optimization algorithm. While the Bekker equation had traditionally been employed as a widely accepted method for predicting soil pressure-sinkage behavior, it typically disregarded the influence of sinkage velocity of the soil. However, the findings revealed the significant impact of sinkage velocity on the parameters governing the soil deformation response. The trained DNN successfully incorporated the sinkage velocity into its structure and provided accurate results with an MSE value of 0.0871.
The relationship between machine and soil
J. Taghinazhad; S. Rahmani
Abstract
IntroductionThe harvesting stage is the most crucial phase in peanut production. In other words, one of the critical stages in producing this product is the harvest stage. Although it has its difficulties, this stage is associated with significant losses, which experts attribute to the high economic ...
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IntroductionThe harvesting stage is the most crucial phase in peanut production. In other words, one of the critical stages in producing this product is the harvest stage. Although it has its difficulties, this stage is associated with significant losses, which experts attribute to the high economic value of peanuts. In recent years, farmers in the Moghan Plain have also started considering this product due to the special conditions of the Iranian economy. In 2020, this study investigated three methods of peanut harvesting in two stages: manual, tractor-mounted thresher (semi-mechanized), and harvesting with a pull-type combine. The first stage involves the complete removal of the plants from the soil, while the second stage involves drying and separating the peanut pod from the plant in Moghan.Methods and MaterialsThe experiment followed a split-plot design in the form of randomized complete blocks with four replications. The main plot consisted of soil moisture levels at harvest time, which were tested at three different levels: a1- 21%, a2- 18%, and a3- 15%. The sub-plot involved testing the separation of peanut pods from the plant using three different methods: b1- combine harvesting, b2- harvesting with a tractor-mounted thresher, and b3- manual harvesting. The study evaluated important harvest indicators such as quantitative loss (first and second-stage losses), actual field capacity, harvest time, and the number of required laborers. The results led to the identification of the best harvesting system.Results and DiscussionThe study revealed that the optimal soil moisture content for the initial stage of harvest was 18%. For most parameters, there was a significant difference observed among treatments at the 1% level. The pull-type combine method had the highest farm capacity with a maximum of 0.46 ha per hour, while the manual harvesting method had the lowest capacity with a minimum of 0.006 ha per hour. The total losses ranged between 5.95% and 10.58%, with the manual harvesting method exhibiting the lowest loss and the pull-type combine method showing the highest loss. Furthermore, the manual harvesting method required more labor compared to the other methods.ConclusionBased on the obtained results, it is recommended to use a pull-type combine for the early harvesting of peanuts and a manual method for obtaining high-quality peanuts in the Moghan region.
The relationship between machine and soil
H. Mahboub Yangeje; A. Mardani
Abstract
IntroductionSeedbed preparation, seeding, and transplanting are usually based on mechanical soil tillage. Tillage by cutting, mixing, overturning, and loosening the soil can modify the physical, mechanical, and biological properties of soil. These days, because of soil protection, the use of tillage ...
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IntroductionSeedbed preparation, seeding, and transplanting are usually based on mechanical soil tillage. Tillage by cutting, mixing, overturning, and loosening the soil can modify the physical, mechanical, and biological properties of soil. These days, because of soil protection, the use of tillage tools is less and less recommended, and some implements such as cultivators are preferred to primary tillage tools such as plows. Experimental study of soil-tool interaction and field measurements of the mechanics of tillage tools are usually time-consuming and costly. On the other hand, the variety of variables and uncontrolled conditions add other dimensions to the complexity of this method. Also, the experimental and analytical methods do not have a comprehensive view of stress distribution and soil deformation in the soil-tool interaction process.Materials and MethodsThe main purpose of this study is to validate the results of numerical simulations in two phases of experimental tests: in soil bin environment and in finite element computer simulations. Experimental tests were performed in the soil bin environment of the Department of Mechanical Engineering of Biosystems, Urmia University, which has a soil bin facility with dimensions of length and width of 24 and 2 m, respectively, and has clay loam soil. Before experimental tests, soil preparation was performed by using some special tillage implements (harrow, leveler, and roller) which were attached to the soil bin (Figure.1). For experimental tests, a mechanism set consisting of two cultivator blades with a width of 15cm, a length of 20cm, and at a spacing of 35cm from each other was prepared and constructed. The relevant mechanism is designed to have the ability to change the tillage depth. Data were collected at three different soil depth levels of 6, 10, and 14cm in the soil bin with three replications. Data recording was performed using a 10-channel data logger with load cell connectivity and data storage ability. Also, in this study, the Drucker-Prager model as a finite element simulation method was used to calculate the stress during the soil-tool relationship. ABAQUS 6.10.1 software was used to simulate the cultivator tine. To solve the problem, the soil parameters were defined as presented in Table 1, and then the interaction between the soil-tool model and the necessary constraints, including boundary conditions, were defined. In the next step, meshing was applied to the constructed model.Results and DiscussionIn the results section, first, the results related to the amount of traction force required for the tillage tine in the simulation were calculated and then compared with the soil bin experimental tests. The traction force of the finite element simulation results for three tillage depths of 6, 10, and 14 cm in three principal directions is shown in Figure 4. A comparison of simulation and experimental results showed that there is a good agreement between them. In comparison, the simulation error range of the three depths of 6, 10, and 14 cm has shown 7.3, 5.6, and 4.16% at a speed of 2.5 kmh-1, respectively, as the velocity studied in this research. In the next section, the results of stress distribution contours in the soil and finally the overlap of the blade effect were discussed. Figure 6 shows the status of stress contours at three depths. By increasing the depth of the tine at the three depth levels studied, the stress range is shifted from the soil surface to its depth. For this purpose, at the maximum depth studied in this study (14 cm), it shows that the stress propagation to the soil surface is less than at other depths. Also, with decreasing depth, for a depth of 6 cm, the maximum stress was on the top soil surface, in other words, more deformation was seen on the soil surface.ConclusionComparing the simulation results for predicting traction force with the results of experimental tests has led to relatively acceptable results and the maximum traction force prediction error at different depths has been about 7.3%.The distribution of stress in the soil was observed due to the tine depth. The highest intensity of stress propagation was observed at the soil surface; and the highest soil surface deformation at a depth of 6 cm. With increasing depth, both parameters of stress and soil surface deformation have decreased. According to the results of the studied blades, it is better to use these types of tillage tools only at lower depths. Also, in evaluating the overlap of the soil loosening zone in the side-by-side tines, it proves the superiority of the tine performance at lower depths.
The relationship between machine and soil
S. M. Seyedan; A. Heidari
Abstract
IntroductionSoil protection against water and wind erosion is of great importance. Since most soils of arid and semi-arid regions of Iran are poor in organic matter and continuous use of conventional tillage (moldboard plow) has increased the severity of soil organic matter depletion and degradation ...
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IntroductionSoil protection against water and wind erosion is of great importance. Since most soils of arid and semi-arid regions of Iran are poor in organic matter and continuous use of conventional tillage (moldboard plow) has increased the severity of soil organic matter depletion and degradation of soil structure. Therefore replacing conventional tillage with conservation tillage (reduced tillage and no tillage) is needed to improve soil structure and increase soil organic matter. Due to the increasing population growth and the limitation of arable land, it is necessary to remove the fallow year in dryland. Legumes are crops that can be in rotation with wheat. Materials and MethodsThis study was conducted to evaluate the effect of crop rotation and different tillage systems on rain-fed wheat farming in Kaboudarahang Township during 2012-2014. The experiment was conducted as split-plot in a randomized complete block design with three replications. In this study, different crop rotations including fallow-wheat rotation, and chickpea-wheat rotation as main plots and different tillage systems including conventional tillage (moldboard plow + power harrow), conservation tillage (chisel plow equipped with roller), conservation tillage (sweep plow equipped with roller) and direct drilling were investigated as subplots.In the economic evaluation of this project, the economic impacts of the treatments were analyzed using the partial budgeting method and the cost-benefit ratio. For this purpose, the difference between treatments income and cost compared with control treatment has been calculated and compared. The differences in the benefits of the treatments are due to the different yields of wheat. Results and DiscussionResults showed:1- The highest wheat yield in the first and second years of the study was 605.3 and 2135.1 kg ha-1, respectively in rotation of fallow wheat.2- In the first year, the highest wheat yield (690.7 kg ha-1) was related to direct planting (no tillage), but in the second year, the highest yield (2268.6 kg ha-1) was related to conservation tillage (sweep blades + roller).3- In the first and second year, the highest value of treatment was related to direct planting and conservation tillage (sweep tiller + roller), respectively.4- In the chickpea-wheat rotation, the highest net income in the first and second year was related to direct planting and conservation tillage (sweep + roller), respectively. Thebenefit-cost ratio in the conservation tillage (sweep + roller) (second year) and direct drilling (first year) methods shows that for each rial of expenses, 5.7 and 2.8 rials can be earned respectively. Therefore, economically, these tillage treatments are superior to the control treatment (conventional cultivation).5- In the wheat rotation, the highest net income in the first and second year was related to direct planting and conservation tillage (sweep + roller), respectively. The benefit-cost ratio in the conservation tillage (sweep + roller) (second year) and direct drilling (first year) methods shows that for each rial of expenses, 4.2 and 1.3 rials can be earned respectively. Therefore, it is economically justified and these tillage treatments are superior to the control treatment (conventional tillage).ConclusionThe results of this study showed that in the first and second years, economically the direct method and the conservation tillage treatment (sweep blades + roller) were superior to the conventional method, respectively. Therefore, conservation tillage methods can be replaced by the conventional method (plowing with moldboard plow) in dryland farming. Also, in dry years, direct cultivation (no tillage) is a good and economical method.
