INMATEH - Agricultural Engineering

19-28

Authors: Vezirov, Ch. Z.; Atanasov, At. Z.; Vlăduț, V. N.

A method and procedure for automatic calculation of field capacity and fuel consumption of mobile machinery with tanks, hoppers and bunkers is suggested. They are based on a combination of two well-founded approaches: East-European and North-American. To increase its calculation area some applications for machines with containers as grain, fertilizer, solution, etc. are added. An example of five linked field operations, namely potato transportation, fertilization, spraying, planting and harvesting is presented. A list of needed information with relations between them and main indices of agricultural aggregates is prepared. For convenience and objectivity calculations are automated with spreadsheets.

41-50

Authors: Xie, Q.J.; Liu, F.Y.; Yang, M..J.; Liu, J.; Yang, S.H.; Xie, S.Y.

Well cellar seedling transplanting can effectively avoid series of problems such as long recovery time and poor uniformity of seedlings caused by the server climate conditions outside. Well cellar making is quite difficult in the upland with low moisture content. An opener with large socket was newly designed for the well cellar making. The well cellar making process was simulated by means of discrete element method (DEM), and its verification was qualified by soil bin test, with a relative error 7.46%. Taking arc radius of the opener socket, rotation speed and penetration speed as control factors, and collapse rate of the cellar hole as evaluation index, the influence of control factors on the collapse rate and their significance were obtained by Box-Behnken Design (BBD) test and analysis of variance (ANOVA). A quadratic regression equation of collapse rate with control factors was established, and the optimal parameters of the control factors were obtained as arc radius 128 mm, rotation speed 380 r/min and penetration speed 0.15 m/s, with the minimum collapse rate 22.70%. The collapse rate of the newly designed well cellar opener decreased much compared to the traditional one.

61-72

Authors: Yingmin, Chen; Haiyan, Song; Rui, Zhao; Qin, Su

To ensure optimum peach quality during precooling, air supply temperature within the precooled facility should be precisely controlled. Three-dimensional unsteady computational fluid dynamics (CFD) model was established in this research, taking air supply temperature as an influencing factor, a dynamic simulation of this model was performed based on Fluent, and its reliability was verified through experiments. Simulation results showed that the decrease of air supply temperature did not affect the 7/8ths cooling time (SECT) significantly, but shortened the cooling time of the fruit which was cooled from the initial temperature to a fixed temperature, especially when air supply temperature dropped below 4oC, its corresponding cooling time showed a trend of steady variation. Meanwhile, respiration rate of 6-8 oC was about twice as high as that of 2-4 oC, its corresponding moisture loss was also increased by 34.71-39.74%. Thus, the range of 2-4 oC was more suitable for quick precooling peaches after harvest. Experiments showed that the root mean square error (RMSE) of 0.7 and 2.7 m·s-1 were 0.747 and 0.836 oC, respectively. It could be seen that simulation results were in good agreement with experimental results, which fully verified the feasibility and high accuracy of this new modeling method. Finally, this study can provide a reliable reference for establishing an accurate precooling numerical model, and rationally optimizing air supply temperature range of fruits precooling experiment to maintain its high quality.

81-90

Authors: Dorokhov, Alexey Semenovich; Ponomarev, Andrey Grigoryevich; Zernov, Vitaly Nikolaevich; Petukhov, Sergey Nikolaevich; Aksenov, Alexander Gennadievich; Sibirev, Aleksey Viktorovich

Structural layouts of coulters and their groups in potato planters are justified in the article based on the morphological features of the potato plant, its requirements for growing conditions and ensuring the quality of the planting process. The purpose of coulter groups is to form a bed for placing tubers with a loose layer of soil in 5-8 cm and sealing them with loosened soil to a certain depth. To substantiate the type of potato planter coulters that meet the requirements for potato growing conditions to the maximum extent possible, optimize the parameters of coulter groups that automatically ensure the stability of the coulter travel depth when imitating irregularities of the field microrelief. A comparative analysis of the impact on the soil of the most common anchor coulters with a blunt angle of soil entry and a sharp angle with an individual floating suspension is given, and indicators of the quality of their operation are described. It was found that coulters with an individual floating suspension and an acute angle of soil entry meet the requirements for potato growing conditions to the maximum extent possible. In order to ensure travel stabilization of such a coulter at a given depth when imitating field irregularities, a version of the coulter group has been developed that provides automatic correction of the coulter's angle of attack when changing its travel depth. Experimental studies have optimized the parameters of the coulter suspension that ensure automatic imitation of field microrelief irregularities up to 20 cm deep within the initial requirements for potato planting machines. Coulters with an individual floating suspension and a sharp angle of soil entry most fully meet the requirements for potato growing conditions to the maximum extent possible. A coulter group with a suspension aspect ratio of 150:200:400:400 cm and an acute angle of coulter entry into the soil provides automatic maintenance of the set coulter travel depth within the initial requirements (±2 cm) for irregularities in the field microrelief of up to 200 mm. In this case, the bottom and walls of the furrow are not compacted.

99-108

Authors: Wang, Tiejun; Wang, Tieliang; Wang, Ruili; Liu, Kai; Gong, Yuanjuan

In this study, a segmented type mixer with double spiral ribbon was designed to destroy choking and accumulation of agricultural waste in the mixing process, by improving the mixing uniformity and reducing the residual amount of maize straw and cow dung. To determine the optimal working parameters of the mixer, the ternary quadratic regression orthogonal rotation combined experiment was carried out by using the mixing uniformity and residual rate of material as the evaluation indexes and the spindle speed, full coefficient and mixing time as the influencing factors. The results showed that the order of the influences on the mixing uniformity was spindle speed>mixing time>fullness coefficient, and the order of the influences on the residual rate of material was fullness factor>spindle speed>mixing time. The study established a regression model of influencing factors and evaluation indexes, and analysed the influence of significant factors and their interaction on evaluation indexes. The optimum combination after parameter optimization based on response surface method was determined to be as follows: spindle speed of 38.00rad/min, full coefficient of 55.00%, mixing time of 9.33min. While the mixing uniformity and residual rate of material corresponding to the verification test were 91.25% and 95.19%, respectively, the relative error of the predicted result was less than 0.5%. The study meets the requirements of mixing agricultural waste materials to make fertilizers, and provides technical solutions for improving the localized resource utilization of agricultural waste.

131-136

Authors: Ito, Ryoei; Kajisa, Takamitsu

This study proposes a measurement system that comprises an e-Tape water level sensor, Arduino and XBee. The system was considered a success because of the linear relation between measured voltage signals and water depths obtained by it. This linearity was essential because Arduino does not have non-linear calculation ability. As a result, the numerical order of RMSE in measuring water depth using this system was obtained as 3.52 mm. For measuring water consumption for 1 day at the standard scale of paddy fields in Japan, water consumption can be estimated using the system below non-flowing water surfaces. However, when there is water flow, it will be difficult to estimate water consumption because discharge errors may be cumulative.

145-154

Authors: Su, Hongjie; Cui, Hongmei; Li, Feiyu; Fan, Teng

Through the mechanical analysis of air-pressure subsoiler, it is found that the main factors affecting its tractive resistance are the air pressure injected into the soil, the soil cohesion, the length and width of the shovel surface, the soil disturbance coefficient, and moving speed of the subsoiler. The traditional air-pressure subsoiler was redesigned to solve the problem of large tractive resistance. In the soil trench experiment, the subsoiling shovel’s shape, the air pressure, and the position of air hole were used as test factors, and the ratio of the traction resistance of the shovel to the soil disturbance, namely SDF (Specific Draft Force), was used as the evaluation index. By the response surface test method and analysing the soil disturbance and the tractive resistance, it is determined that rectangular subsoiling shovel with the air hole in the upper part of the shovel is the optimal under the pressure of 1.2 MPa.

169-178

Authors: Mosalanejad, Hossein; Minaei, Saeid; Borghei, Alimohammad; Farzaneh, Behfar

This study investigates the potential of using a sprayer robot for the greenhouse with bell-pepper plants and compares its performance with the backpack sprayer. The infrared sensors were used to navigate the robot and the ultrasonic sensors were used to distinguish the beginning of each row for automatic spraying. Results showed that the robot's guidance was done well by the infrared sensor. It was capable for spraying plants on both sides of the greenhouse simultaneously with ultrasonic sensor. The sprayer robot had better spray quality and lower solution consumption and spraying time and spray loss than the backpack sprayer.

189-198

Authors: Tan, Kun; Sun, Sanmin; Du, Liangzong; Zhou, Shaoliang

This research aimed to develop an information acquisition and intelligent irrigation decision system based on the agricultural Internet of Things (IoT). The system consists of a field control terminal and a remote client, realizing control, real-time display, alarm, and other functions. The user may apply the upper and lower limit of soil relative water content as the irrigation decision threshold. The system automatically controls irrigation according to the threshold. In the calculation and analysis part of the system, the programming software Keil 5 was used for data collection and monitoring, database comparison, calculation and analysis, irrigation decision, and other functions.

221-230

Authors: Wang Long; Hu, Can; He, Xiaowei; Guo, Wensong; Wang, Xufeng; Hou, Shulin

In the current paper, a coated cotton-seed discrete element model was established. Furthermore, we designed a device for the simultaneous determination of the repose and accumulation angles, and Plackett–Burman and central composite design (CCD) tests were performed with the repose and accumulation angles as the test indexes. The static friction coefficient between seeds (SFCC) and the dynamic friction coefficient between seeds (DFCC) were observed to have a significant influence on the indexes and were thus selected for the subsequent analysis (P < 0.05). Analysis of variance revealed the terms of these two parameters to have a significant effect on the relative error of the repose angle (RERA) and the relative error of accumulation angles (REAA) (P < 0.05). A solution to the proposed mathematical model was determined via the NSGA-Ⅱ genetic algorithm and the Pareto optimal solution set was obtained. Based on multi-objective optimization, the SFCC and DFCC were determined as 0.174 and 0.068, for RERA and REAA values of 1.715% and 1.712%, respectively. Simulations were then performed using the optimal parameters. Results of the T-test demonstrated that there were no significant differences between the simulated and physical test results.

241-248

Authors: Yi, Qiu; Xiaofeng, Dai; Zhi, Chen; Nianzu, Dai; Longkai, Mi

In order to explore the temporal and spatial distribution and motion state of the grains of wheatgrass (Agropyron) seeds and powder in pelleting process, and to find the optimal inlet air speed of pelleting premixer, the pelleting forming mechanism was revealed. Based on Herz-Mindlin contact theory, the contact mechanics model of seed and powder was established. Besides, CPFD software was used to model and simulate the pelleting premixer, and the contact, collision and friction rules among particles were analysed. The simulation and experimental results show that with the increase of inlet wind speed, the bed expansion increases and the unit volume particle concentration decreases, while the air pressure difference only slightly increases. When the inlet wind speed is set at 3.5 m/s, the atomizing nozzle velocity is set at 4.1 m/s, and the seed coating agent flow rate is 0.36 L/min, the particles are suspended due to air isolation, forming a spouted fluidized bed. It is good for seed and powder contact and rapid prototyping. In this time, the pelleting qualified rate was 95.8%. The results provide theoretical basis and technical support for the research of small irregular seeds pelletizing technology.

261-270

Authors: Liu, Shaohua; He, Junlin; Wu, Nan

A comb-type harvesting test bench was designed to address low fruit collection rate and theoretical analysis and simulation analysis of the harvesting process were carried out in this work. Single factor simulation experiment and bench experiment were carried out, and fruit collection rate was used as the evaluation index. The motor speed, bending angle of comb teeth and radial diameter of comb teeth arrangement were selected as the experimental factors. Results showed that the collection rate decreased with the increase of motor speed; and increased with the increase of the bending angle of comb teeth or the radial diameter of comb teeth arrangement. The orthogonal experiment of three-factor and three-level quadratic rotation centre combination was performed. The results showed that motor speed had the largest effect on collection rate, followed by radial diameter of comb teeth arrangement and bending angle of comb teeth. The optimal parameter combination was predicted by the response surface model as follows: motor speed of 25 r/min, bending angle of comb teeth of 120°, radial diameter of comb teeth arrangement of 868.45 mm and correspondingly the collection rate reached 91.51%. Based on actual harvesting efficiency and the machining problems of the test bench, the bench experiment was performed with the motor speed of 25 r/min, the bending angle of comb teeth of 120°, the radial diameter of comb teeth arrangement of 900 mm, and the collection rate was 93.82%. The relative error with the predicted optimal result was 2.48%, achieving the purpose of improving the collection rate.

281-290

Authors: Qing, Yiren; Li, Yaoming; Xu, Lizhang; Ma, Zheng

During the mechanical harvesting of rapeseed, the impact of the rotating reel tine on rape can easily cause the pods to burst and seeds drop. However, the specific size of the pod shatter resistance suitable for mechanical harvesting is unsure. In this paper the impact force on the rape was analysed through the measurement and wireless transmission of stress change of the tine. A two-degree-of-freedom (2-DOF) collision tester of pod resistance for field testing was used. The results of the shatter resistance index (SRI) under 2-DOF method and the cracking force under ripping method were compared. According to the results of SRI, cracking force and tine impact force, the expected field SRI was determined. The results show that the tine impact forces at the low reel speed of 18 revs min-1 was 1.76 N. The 2-DOF method results are reliable and the SRI is significantly correlated with the cracking force. The SRI should be over 0.576 to be greater than the impact force under the low reel speed, however, only 14.8% of the tested varieties could satisfy. It indicates the resistance of the commercial varieties is generally poor and need to strengthen.

301-308

Authors: González-Cueto, O.; Castillo-Rodríguez, J.A.; Ávalos-Clavelo, J.L.; López-Bravo E.; Herrera-Suárez, M.; Salcerio Salaberry, R.A.

Field efficiency is a main factor for obtaining high productivity of agricultural machinery. The aim of this paper was to determine the field efficiency of KTP 2M and CASE IH 8000 sugarcane harvester machines, working with different lengths of cutting fronts. The research was carried out in the Panchito Gómez Toro area of production, belonging to Sugar Enterprise, Villa Clara, during February and March 2020. The main movement times of the harvester inside the field was obtained by stop watch, as well as the fuel consumption during the works. The influence of the length of the cutting fronts on the turning time, time for completing the task and field efficiency were determined according to the sugarcane yield. The results show that lengths of cutting front less than 300 m, represent greater losses in time and higher rate of fuel consumption.Lengths of cutting fronts greater than 500 m, do not represent an increase in field efficiency.

317-325

Authors: Konstantinov, Yu.V.; Akimov, A.P. ; Medvedev, V.I.; Terentyev, A.G

Flat circular discs in powered operation mode create driving forces. These forces enable to decrease the wheel slippage of the energy saturated tractor of tillage unit and to reduce the specific energy consumption. The objective of this study was to develop a technique that enables to determine the driving disc optimal parameters for maximum efficiency criterion. The earlier developed mathematical model of soil-disc interaction was used for this purpose. Soil properties in the model are characterized by means of two empirical constants. The relative depth and the kinematic parameter determine the disc operation mode. It was shown that the driving disc can operate with high efficiency, if the disc operates at the optimal values of the parameters. The driving disc efficiency can achieve the value about fifty percent. The experimental results confirmed the adequacy of the technique. The discrepancy between the predicted and field experimental values of driving forces and applied moments was about 25%. The proposed technique can be modified to optimize the parameters of other powered rotary tools of tillage machines and units.

335-344

Authors: Wang, Li; Li, Shuo; Lv, Dianji; Ekhlo, Ghay

In recent years, combine harvesters are increasingly developing in the direction of large-scale, technology, automation and intelligence, and more and more electrical equipment is installed on combine harvesters. The electrical system of combine harvester is prone to failure when it works in high temperature, high humidity, dusty and strong vibration environment. Parameters to be adjusted in the header system of combine harvester include header height, drum height, drum front and back position, cutting frequency and drum speed. Aiming at the inconvenience of debugging and testing the measurement and control system of combine harvester in the field operation environment, an intelligent control test bed of combine harvester was designed. The test bed can simulate various intelligent control algorithms of combine harvester in laboratory environment, control the forward speed of combine harvester according to data processing results, classify faults, and send and print stored data through serial communication. Experiments show that the system works stably and reliably, and can realize the integration of the monitoring system of combine harvester operation process. It can save costs and improve efficiency in the application of the monitoring system of combine harvester.

355-364

Authors: Paun, A.; Stroescu, Gh.; Zaica, Al.; Ştefan, V.; Olan, M.; Yasbeck Khozamy, S.

The production and quality of any agricultural crop is determined both by the factors acting from the moment of sowing until harvesting, as well as by those that directly influence the seeds before sowing. In the organic cultivation of cereals, industrial plants, vegetables, medicinal plants, the seeds must be clean without any impurities because the maintenance of these crops does not allow using chemicals. There is a number of technologies and pieces of equipment for separating impurities. In case of separating impurities from the mass of small seeds, especially vegetable and flower seeds, the use of separation on sieves is very expensive because compared to other crops, vegetable seeds are produced in small quantities (except for beans, peas, lentils, etc.) and have a wide variety of characteristics. Vegetables belong to a large number of plant families. This is why their seeds have a very different structure, shape, size and chemical composition. To overcome these challenges, the experimental model Seed conditioning module for vegetable species – MCSL, which separates impurities by using the aerodynamic properties of the seeds was developed. Seed conditioning module for vegetable species is designed to improve the technologies of organic seed production for vegetable seeds, flowers, industrial plants, cereals and to solve practical problems regarding seed production in the case of vegetable crops. Starting from these considerations, the paper will present theoretical and experimental information on the influence of some factors on the aerodynamic properties of cereal seeds, vegetables and industrial plants. The quality of seed separation in this module depends on the degree of uniformity of the air velocity field in the working area, on the stability of this field and on its extent.

375-384

Authors: Ran, Xu; Mathkour, Chandra

With the development of engine supercharging technology and the application of in-cylinder direct injection technology, engines with high power and torque have become a trend. Crankshaft, as one of the most important and expensive parts in tractor engine, plays the role of transforming linear motion into circular rotation. The damage and destruction of crankshaft will lead to the damage of other parts of the engine, which makes the engine unable to work normally, and its stability affects the reliability of the whole engine to a great extent. The main failure form of tractor engine crankshaft is bending fatigue failure, so alternating bending stress occurs in crankshaft, which may cause fatigue failure of crankshaft. Crankshaft is one of the important components of tractor engine, and its stress is complex, which is the key and difficult point of engine design. In this paper, the crankshaft of tractor engine is analysed and studied based on compound supercharging technology, so that the dynamic characteristics of the engine are deeply understood, the action law of dynamic working load is mastered, the response analysis and evaluation of the system are carried out, and the optimization method of crankshaft mechanism of agricultural tractor engine is found out.

397-404

Authors: Ardiansah, Irfan; Bafdal, Nurpilihan; Bono, Awang; Suryadi, Edy; Husnuzhan, Ramadhoni

The greenhouse which is a building used to manipulate the micro-climate is an essential building for plant growth. Greenhouses have one or more devices that are used to monitor their internal environments against changes in micro-climate. The problem is that some devices are metal-based devices and plastics that can be deformed, such as electronic devices, one of which is a micro-climate monitoring device, so a shield that can protect the device but does not interfere with the sensor readings is needed. The purpose of this study was to make and test a plastic-based container called Duradus Junction Box, which has six removable ventilation openings to measure the micro-climate data. This study uses five Duradus Junction Boxes with different numbers of ventilation openings, a micro-controller connected to the air temperature and relative humidity sensor, and a MicroSD module to record all micro-climate data, all devices being then tested simultaneously for 30 days. Statistically, after using One Way ANOVA, this study found that micro-climate measurements result for actual devices data can be considered similar because the P-value for temperature (0.886) and relative humidity (0.917) is greater than alpha level of 0.05. However, when reading the recorded data for both parameters, it can be seen that micro-climate data inside all shields are slightly higher than actual microclimate data ranging from 1 to 2oC for air temperature and 1 to 3% for air relative humidity.

413-424

Authors: Zeng, Fandi; Li, Xuying; Zhang, Yongzhi; Zhao, Zhiwei; Cheng, Cheng

Dynamic soil behaviour at the contact interface during transplanting makes it difficult to ensure transplanting quality. To solve this problem, the Hertz-Mindlin with bonding contact model was used to calibrate the parameters of soils in Inner Mongolia. Based on the response surface design principle, four-factor and three-level tests were performed using the repose angle as an evaluation index, and the following influence factors were considered: the soil-soil restoration coefficient, the soil-steel restoration coeficient, the soil-steel static friction coefficient and the soil-steel static friction coefficient. A regression model was analysed, and an optimization procedure yielded the following optimum combination of parameters: a soil-soil restoration coefficient of 0.45, a soil-steel restoration coefficient of 0.35, a soil-steel static friction coefficient of 0.85 and a soil-steel rolling friction coefficient of 0.13. This optimal combination was used to simulate the soil at the contact interface. The particle dynamic behaviour and soil particle mass flow were used to analyse the soil dynamic behaviour, showing that the average mass flow during the gradual opening of the duckbilled planter tends to increase over time; when the duckbilled planter gradually leaves soil, the contact interface of soil particles in the corner of the duckbilled planter unit causes a reduction in the fluctuation range of the soil mass flow, which exhibits a wave-like change. After the duckbilled planter has left soil, the contact interface of the soil changes tends to stabilize. The duckbilled planter-soil discrete element simulation model was verified. The results of this study provide a reference for the optimal design of a duckbilled planter structure.

434-442

Authors: Zhang, Shuo; Chen, Qingyu; Liu, Jinyi; Chen, Yu; Chen, Jun; Jin, Hongling; Luo, Tongyun

Vegetable industry occupies a significant position in the world agricultural production, China has been the largest vegetable producing country in the world. However, the mechanization of vegetable production is still in the initial stage. There are many problems such as complex environment, non-uniform agronomy, various kinds of agricultural machinery etc. In order to meet the varied requirements of vegetable field work, in this paper, a new type of high-efficiency vegetable field operation power equipment was developed by adopting the idea of "frame-type", and the key components are developed. They include ground gap adjusting mechanism, wheel spacing adjusting mechanism, inter-axle hitch mechanism, the rear hitch mechanism and frame. The vibration modal analysis and stiffness analysis of the frame are carried out by ANSYS, which proves that the frame design is reasonable and meets the use requirements. Finally, a prototype was made and field experiments were carried out. The results showed that the maximum running speed of the multifunctional vegetable field machine was 16 km/h, the maximum operating speed was 8 km/h, the maximum gradient was 20, and the adjustable range of ground clearance was 400~800 mm. The adjustable range of wheel spacing was 1600-2000 mm.

453-460

Authors: Yan, Hongwen, Liu, Zhenyu; Cui, Qingliang

Individual pig recognition is an essential step for accurate breeding and intelligent management of pigs. To realize individual pig identification, applicable dataset of pigs needs to be built. For pigs’ behaviour is difficult to control, the data acquisition is of great difficulty and low efficiency. In addition, few reports on pig face detection are there at home and abroad, thus, face data acquisition faces more difficulty. In this study, double open mv3 digital cameras were adopted, and the approach of starting the pig face acquisition program by acquiring pig figure with a vertical camera to calculate the slope of their back before sending a signal to the horizontal camera was adopted. The image brightness was calculated based on RGB function: when the value was less than 90, the supplementary light system would be started by L298 module, and when the value was more than 120, the acquisition system would be restarted. This study provides a reference for solving the key problem of automatic acquisition of pig face data for pig face detection.

469-478

Authors: Dai, Nianzu; Hou, Zhanfeng; Qiu, Yi ; Zhang, Xiwen

In order to quantitatively describe the influence between the mixing process and the pelleting quality of the vibration pelletizer, this paper uses EDEM to conduct a numerical simulation study on the uniformity of the seeds and powder mixing of the pelleting machine under vibration force field. Meanwhile, a single factor test was established to verify the feasibility of numerical simulation. The results show that the coefficient of variation CV is the smallest and the mixing uniformity between the seeds and powder is the highest when the vibration frequency is 20Hz, the rotation speed is 45r/min, the tilt angle is 40° during numerical simulation. The pelleting qualified rate J and single seed rate P as the test index of the mixing uniformity of seed pelleting shows the optimum value in the single factor test, EDEM can be used to analyse the mixing uniformity and pelleting quality in pelletizer. The results of orthogonal experiment indicated that the best combination of parameters was obtained as follows: vibration frequency of 20Hz, rotation speed of 45r/min and tilt angle of 40°, the mixing uniformity of seeds and powder and the pelleting quality of Agropyron seeds are the highest. This study can effectively provide reference for design of pelleting machine of small seeds under vibration force field.

488-497

Authors: Cardei, P.; Muraru, V.; Muraru, S.; Sfaru, R.; Muraru-Ionel, C.

The article presents results of some test sketches - validation and ordering - of the mathematical models proposed for the physical law rank on soil tillage draft force. The results constitute the continuation and partial completion of a method of testing - validation and ordering - the models proposed and published by researchers in the specialized literature of the last seventy years. The material defines and completes the method (initially only a validation method), up to a method of ordering the models according to their accuracy in relation to the experimental results. The proposed tests are intended to increase the coherence of research in the field of searching for a physical law of soil tillage draft force, assuming that it exists. The method can also be applied in case of other physical laws in research, construction or improvement stage.