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Multiple compression and impact of the air-assisted centralized seed metering device on rice seeds during high-speed sowing (≥12km/h) can easily lead to seed damage and adversely affects the emergence rate. This study aims to explore the damage of rice seeds under single and multiple mechanical compression in the air-assisted centralized seed metering device, according to the damage accumulation theory. The fitting equations of seed impact damage and compression were clarified to determine the matching range of stirring speed and the conveying airflow parameters during high-speed seeding. A systematic analysis was also implemented to explore where the seed was damaged under the repeated compression by the seed mixing device during high-speed seeding. The multiple impacts of airflow were evaluated during transportation and distribution in the air-assisted centralized seed metering device. The single compression test was carried out on the hybrid rice and conventional rice varieties. An elastic-plastic model was constructed suitable for rice seeds, in order to determine the critical value of elastic- plastic deformation. The multiple equal displacement compression tests were then carried out to determine the process of damage to rice seeds under multiple compressions. The critical deformation of rice seeds was determined and verified to combine with the seed germination rate test under multiple compressions. According to the conservation of energy, the critical speed was constructed at which the rice seeds were compressed and damaged by the stirring device. The fitting equation of impact damage and compression was combined to analyze the speed of seed airflow impact damage. The results showed that the crushing forces of conventional and hybrid rice seeds under single compression were (118.4±35.6) N and (113.2±39.9) N, respectively, the deformation during crushing was (0.59±0.07) mm and (0.63±0.11) mm, respectively, and the average critical deformation of elastic plasticity was 0.4 and 0.44 mm, respectively. In multiple compression tests, the maximum compression force of the seeds remained consistent, when the compression distance was less than the elastic-plastic average critical deformation; Once the compression distance was greater than the critical elastoplastic deformation, the maximum compressive force on the seed decreased gradually. Verification tests were also performed on the rice seeds germination rate. There was the a 0.44 mm critical deformation of hybrid rice seeds that caused damage. When the deformation of compressed seeds was less than 0.44 mm, there was no significant difference in the germination rate between compressed and uncompressed seeds after multiple compressions; When the compression deformation of the seeds was greater than 0.44 mm, the germination rate of rice seeds decreased after multiple cycles of compression. Therefore, the deformation of rice seeds after being loaded should be avoided to be greater than 0.44 mm. After that, the rotation speed range of the stirring device should be lower than 125 r/min and the seed transport speed should be lower than 8.5 m/s, in order to reduce the compression and impact damage of the air- assisted centralized seed metering device on rice seeds. This finding can provide a theoretical basis and parameter range to match the operating parameters during rice high-speed sowing. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Persistent drought can often occur during the rapeseed sowing period in the mid-lower reaches of the Yangtze River. Traditional rotary tillage devices cannot fully meet the large-scale production in recent years, due mainly to the excessive stubble residue after rice harvesting, less straw returning, and low seedling emergence rates. In this study, the rapeseed direct seeding machine was developed with stubble covering using a combined harvester platform. The harvesting, tillage and seeding were integrated into the one. A single operation realized the various tasks, such as collecting, shredding, and covering stubble residue for returning to the field, as well as seedbed preparation and rapeseed sowing. The movement principle of the crankslider mechanism was combined to improve the passability of the machine tool during field operation and transshipment, according to the structural properties of the guide rail vertical suspension device. The structure of the suspension device was also improved by kinematics analysis. There was an effective increase in the ground clearance of the rear suspension tilling and sowing system. As such, the lifting height increased by more than 50%, compared with the suspension device. In addition, the structural parameters of the threshing device were considered to achieve the straw mulching and return to the field. A strawcrushing and side-throwing device was added at the side end of the combine harvester. Furthermore, the rotational speed of the threshing cylinder was the main influencing factor on the qualified rate of straw crushing and the uniformity of straw laying. Dynamics and kinematics analysis was then conducted in the process of straw crushing and throwing. The single- and twofactor three-level central composite experiments were carried out to explore the impact of each test factor on the evaluation indexes, in order to evaluate the working performance of the whole machine. The forward speed of the machine and the engine power output speed were taken as the experimental factors. The experiment indexes were selected as the soil fragmentation rate, flatness of seedbed surface, straw shredding qualification rate, and uniformity of straw spreading. The quality of the seedbed was also evaluated under straw treatments. The response surface model was established to obtain the optimal combination of operational parameters. The experimental results showed that the forward speed and engine power output speed shared significant effects on the soil fragmentation rate, flatness of seedbed surface, straw shredding qualification rate, and uniformity of straw spreading. Once the forward speed was 2.89 km/h and the engine power output speed was 2 210 r/min, the superior performance of the machine was achieved, where the soil fragmentation rate was 85.65%, the flatness of seedbed surface was 20.06 mm, the straw shredding qualification rate was 90.31%, and the uniformity of straw spreading was 89.33%. The verification experiment was carried out using optimized round parameters, i.e., the forward speed was 3 km/h, and the engine power output speed was 2 200 r/min. The overall performance of the machine fully met the requirements, the soil fragmentation rate of 85.69%, flatness of seedbed surface of 21.32 mm, straw shredding qualification rate of 89.35%, and uniformity of straw spreading of 88.07%, with deviations from the optimal of 0.04 percentage pionts, 1.26 mm, 0.96 and 1.26 percentage points, respectively. The finding can provide technical support to the mechanized rapeseed sowing in multifunctional machinery. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Air-assisted centralized metering can be operated at high speed for rice, wheat, and rapeseed. However, the seed stirring device is prone to damage the seeds, leading to the low stability of discharge quantity. In this study, a spiral-inclined flexible seed-stirring device was designed for high-speed, air-assisted, and centralized metering. The influencing factors on the seed damage were determined using Hertz contact theory, including the material properties of the seed stirring rod, the top structure, and the stirring speed. A comparison was made on the variation in the top structure of the seed stirring rod and the contact force of the population over time using EDEM simulation. A systematic investigation was also implemented to clarify the impact of the seed stirring rod on the seed supply. The test results show that the tangential and normal forces of the arcshaped seed stirring rod in contact with the population were smaller than the trapezoidal seed stirring rod. There was better stability of seed supply when the inclination angle of the seed stirring rod was 45°. A single-factor test was conducted on a bench to determine the optimal range of seed stirring speed ratio. The results showed that the rice and wheat seeds performed better within the range of 1-2 seed stirring speed ratios, while the rapeseed seeds were in the range of 0.5-1.5 seed stirring speed ratios. A three-factor, three-level, and quadratic rotation orthogonal experiment was carried out to optimize the influencing factors. A regression model was then established for the damage rate, seed supply rate, and stability coefficient of variation of rice, wheat, and rapeseed. There was an optimal matching relationship between the stirring speed and the operating speed within the range of 10-14 km/h. Field experiments were also conducted to verify the simulation. It was found that the stability coefficients of the variation in the total displacement of rice, wheat, and rapeseed were 1.92%, 1.27%, and 1.14%, respectively, under the optimal combination of parameters, when the operating speed was 12 km/h. The coefficients of variation in the total number of seedlings within 1 m² were 15.47%, 12.98%, and 17.93%, respectively, which fully met the requirements of the standard for the high-speed seeding. The finding can provide a strong reference to achieve high-speed and low-loss seeding in the parameter selection of high-speed, air-assisted, and centralized metering devices for rice, wheat, and rapeseed. [ABSTRACT FROM AUTHOR]

A ditching device has been widely used for rapeseed direct-seeding in the rice-oil rotation areas of the mid-lower reaches of the Yangtze River. However, the high-power consumption and unstable furrow shape cannot fully meet the large-scale production in recent years, when operating at the high speed (≥10 km/h). In this study, a quasi-propeller ditching device was developed with a blade-soil contact surface similar to that of a propeller suitable for high-speed no-tillage rapeseed direct seeder. The ditching blade group was also optimized. A quasi-propeller cutter group consisted of four sets of cutters. The blade layout structure was then determined using kinematics and dynamics. An optimal model of power consumption and soil throwing efficiency was established for the operation of the blade group using dynamic analysis. The key structural parameters and working factors were determined to improve the power saving and soil throwing efficiency in the ranges of parameters. Single-factor tests were conducted on the blade edge type, pitch angle, and bending angle using EDEM software. The results show that the smallest resistance was achieved in the back blade edge type; The blade resistance first decreased and then increased, as the pitch angle increased, whereas, the soil throwing performance decreased significantly; There was a decrease in the overall resistance of the blade group and the soil throwing performance, as the bending angle increased. Once the blade edge structure of the cutter-1, cutter-2, cutter-3, and cutter-4 was the back edge (BE) type, the pitch angles were 7°, 5°, 4°, and 3°, respectively, and the bending angles were 120°, 120°, 90°, and 90°, indicating the relatively small resistance of the cutter group and the better performance of soil throwing. A Box-Behnken simulation test was conducted on the pitch angle, working velocity, and cutter rotary speed, according to a single factor test. A genetic algorithm (GA) was also used for the multi-objective optimization in the power consumption and soil throwing performance. Box-Behnken results showed that the pitch angle, cutter rotary speed, and working velocity greatly contributed to the power consumption. The most significant impact was found on the working velocity, indicating the lower working velocity and the higher cutter rotary speed, while the higher efficiency of soil throwing. After optimization, the optimal pitch angles of cutter-1, cutter-2, cutter-3, and cutter-4 were 6.7°, 4.7°, 3.5°, and 2.5°, respectively; The optimal rotary speeds of the cutter were 540, 620, and 810 r/min, respectively, at the working velocity of 6, 9, and 12 km/h; The power consumption of the optimized blade group was lower than that of the control group and the international IS225 blade group; The total power consumption of the optimized cutter group was reduced by 5.51-28.99 kW, compared with the control group. The higher the working velocity was, the higher the resistance reduction rate was; The reduction rate of resistance was the highest at 12 km/h, about 41%. Field experiments showed that the total power consumption of the optimized ditching device was 15.1-41.8 kW when operating at a speed of 6-12 km/h, with a relative error of less than 10%, compared with the simulation. The width range of the furrow was 421.3-452.7 mm, the depth range was 163.7-178.7 mm, the stability coefficient range of the furrow width was 95.2%-98.6%, and the stability coefficient range of the furrow depth was 93.8%-97.5%. The working velocity also caused the furrow pattern to change from a circular arc to a V-shape. This research can provide a strong reference to improve the high-speed ditching device for the rapeseed direct-seeding in the rice-oil rotation cropping area of the mid-lower reaches of the Yangtze River. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Direct seeding has been one of the most efficient cultivation modes for a wide range of plants, such as rapeseed. Among them, the existing ditching device cannot fully meet the practical direct seeding in recent years, due to the low stability of the furrow shape and the seedbeds on both sides of the furrow. In this study, a propeller-type ditching device was designed to actively open the furrows at high speed (≥10 km/h) and simultaneously distribute the soil in the middle and lower reaches of the Yangtze River. A quasi-propeller ditching blade was then proposed, according to the working mode of propellers. The blade arrangement was determined using kinematic and dynamic analysis. The critical parameters (the pitch and edge structures) were also determined to reduce the cutting resistance. A simulation experiment of the blade cutting was carried out using the discrete element model of the blade cutter-soil system. The simulation results indicated that the cutting resistance first decreased and then increased with the increase of the pitch angle, whereas, the rear grinding edge reduced the soil cutting resistance. The quasi-propeller blade group with the optimal combination of pitch angle and edge structure achieved a resistance torque of 176.6 N·m and a traction resistance reduction of 447.7 N, compared with the straight spoon-blade group with a travel speed of 12 km/h and rotation speed of 810 r/min. The dynamic analysis was implemented to determine the curved structure parameters of the soil homogenizing plate. Furthermore, a soil-distributing simulation experiment was carried out using the ditching cutter-soil distributing plate-soil interaction model. The better performance of soil distributing was achieved, when the camber of the left and right distributing plates was 0.19 and the down-inclination angle was 10° and 7°, respectively. The field experiment indicated that the work quality of the overall device fully met the requirements of direct rapeseed seeding when operating at a high speed of 9-12 km/h. An optimal combination was achieved: the furrow depth was 169.1-188.6 mm, the furrow depth stability coefficient was 92.5%-95.6%, the flatness of the furrow surface was 22.2-23.0 mm, the coefficient of variation of soil distributing on both sides was 14.3% and 17.2%, and the stubble burying rate was 81.96%-87.46%, the operating power consumption at the operating speed of 12 km/h was 66.84 kw. This finding can provide a strong reference for the high-speed no-tillage, ditching, and high-quality seedbed preparation for rapeseed in the rice-oil rotation areas of the mid-lower Yangtze River. [ABSTRACT FROM AUTHOR]

The shovel type seedbed preparation machine is suitable for the preparation of rapeseed seedbeds in the rice-oil rotation area in the mid-lower Yangtze River. It can complete the functions of soil plowing, soil leveling, straw burying, and furrow opening in one operation. However, the unit had large vibration and noise during idling and field operations, which can easily cause wear and tear of key components, reduce work reliability and trouble-free working time, and affect the health and comfort of the driver. In order to solve the problem of large vibration during unit operation, this paper analyzed the theoretical excitation frequency of the main vibration source during the operation of the tractor coupling unit through theoretical calculation, and the vibration acceleration of the unit under idle speed and field operation conditions was tested by using Coco80 dynamic signal Test and analysis system. By using time-domain analysis and frequency-domain analysis, the vibration acceleration at different measuring points under two working conditions was determined, and the main excitation source of the unit was the movement of the shovel type tillage and soil preparation device. Based on the results of the vibration test, a scheme to reduce the vibration of the shovel type seed bed preparation machine was proposed by optimizing the arrangement of the crank phase angle to reduce the combined inertial force and inertia moment of the machine. According to the mass substitution method and kinematics analysis, the inertial force variation trend of a single group of shovel tillage and land preparation devices was obtained. Base on the calculation results, it was further clarified that the inertial force on the whole machine can be reduced by rationally designing the crank phase angle arrangement of the ten groups of mechanisms of the unit. Based on the calculated inertia force on a single group of mechanisms and combined with the crank phase angle of the existing machine tools arrangement, the inertial force and inertial moment force models of ten sets of crank-rocker mechanisms of the whole machine were established, and the arrangement of the crank phase angle that minimizes the total inertial force and inertial moment of the whole machine was obtained by using MATLAB software. Under this crank phase angle arrangement, the total inertial force of the whole machine was basically balanced, and the average absolute value of the total inertia moment in the x and y axes were reduced by 37.40% and 30.09% respectively. In order to verify the vibration reduction effect of changing the crank arrangement on the unit, the acceleration time domain signal was collected from the improved unit at the place where the vibration was relatively large. Compared with the unit before improvement, the total vibration of the measuring points after the improvement was respectively reduced by 36.42% and 31.97% under the conditions of idle speed and field operation. This research can provide reference for the inertia force balance design of planar linkage mechanisms and the research on vibration reduction of agricultural machinery based on planar linkage mechanism groups. [ABSTRACT FROM AUTHOR]

Air-assisted centralized metering devices cannot fully meet the large-scale seed supply during high-speed operations in recent years. It is high demand for better compatibility in the seeding rate and size of rice, wheat, and rapeseed, particularly on the high flowability of rice and wheat. In this study, a type-hole wheel was proposed to specifically design for the compatible mode with rice, wheat, and rapeseed. The number and rotational speed of the hole wheels were rapidly adjusted to allow for the flexible seeding rate in the seeding system, leading to the simultaneous use of rice, wheat, and rapeseed. The spiral arrangement of the hole wheels was used to increase the mobility of seeds within the seed-filling area. Thereby, the stability of seed supply was improved during high-speed seed feeding operations. Mechanical analysis was also carried out on the seed filling, seed carrying, and seed falling stages during the seed supply process. The type-hole structure parameters were determined using the physical characteristics of rice and wheat seeds. A hole wall curve was designed using brachistochrone. EDEM simulation experiments were conducted to analyze the population motion states under different rotational speed conditions at the filling, carrying, and falling stages. The variation curves were derived for the number of seeds that were supplied in the spiral and linear arrangement of the hole wheel with time. The peaks, valleys, and periods of the curves were statistically analyzed. The EDEM simulation experiments show that better performance was achieved at 40 r/min for the rice, wheat, and rapeseed supply stages. There was more outstanding behavior of the dragging and bouncing during the seed-filling stage at 80 r/min. Some seeds cannot fully enter the mold hole during the initial stage of seed carrying. But the seeds were moved down the side wall of the mold hole for the secondary seed filling, as the mold hole wheel rotated. All seeds were fed in a timely manner without any "seed sticking" phenomenon during the seed-feeding stage. Once the number of holes was determined, the pulsation period was inversely proportional to the speed of the hole wheel. The adjacent holes were sequentially misaligned on the hole wheel, when the hole wheel was spirally arranged. The continuous seed filling and feeding performance were improved to reduce the pulsation, indicating a more stable seed supply. Furthermore, the fluctuation range was reduced by more than 30 grains in the spiral arrangement of the shaped hole wheel for the rice and wheat seeds under the same rotational speed conditions, compared with the linear arrangement. The bench test was carried out to determine the rotation speed range with the better seed supply rate and stability. The regression model of seed supply rate was constructed for the rice, wheat, and rapeseed. Therefore, the coefficient of variation was less than 1% for the stability of the seed supply rate, and the seed supply rates were 1 050.62-1 535.87, and 4 171.82-5 073.76 g/min, respectively, for the hybrid rice and wheat seeds, when the number of type-hole wheels was 16, and the speed of seed supply ranges were 30-50, and 50-70 r/min, respectively. In rapeseed, the coefficient of variation was less than 0.5% for the seed supply rate stability, and the range of rapeseed supply rate was 160.42-227.45 g/min, when the number of type-hole wheels was 1, and the rotational speed of seed supply was 20-30 r/min. Moreover, there was a relative error of less than 2% between the regression model and the experimental value of the seed supply rate of rice, wheat, and rape. The field seeding experiment showed that the stability coefficients were 1.32%, 1.16%, and 1.07% for the variation of the total displacement in the collector for the rice, wheat, and rapeseed, respectively when the operating speed was 8-10 km/h. The seeding system fully met the high requirements for the multi-crop seeding operations with the rice, wheat, and rapeseed. This finding can provide a strong reference to optimize the structural parameters of the air-assisted centralized metering device for multiple crops [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Shenyang Agricultural University is the property of Journal of Shenyang Agricultural University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A rapeseed centrifugal metering device has been widely used in field, due to its compact structure, high efficiency, low cost, and low seed crushing rate. The centrifugal force and seed gravity can also be utilized to realize the simultaneous seeding of multiple rows through the seed outlets of the upper edge of the outer cone canister. However, the seeding amount relies mainly on the forward speed of the planter, the filling quality of the inner cone canister, the size of seed particles, and seeding plant space. In this study, a seeding amount control system was designed to improve the performance of the rapeseed centrifugal metering devices. The system consisted of a microcomputer, a seeding detection, a speed measuring, a seed metering drive, and a human interaction module. Specifically, the microcomputer used a singlechip with the type of STM32F103C8T6 as a processor to coordinate the orderly operation of each functional unit. The seeding detection module was developed to real-time monitor the seeding amount of the seed metering device using a photoelectric sensor with the type of PG-602 and a signal amplifier with the type of PG-610. The speed measuring module was to monitor the sowing speed using a hall sensor with a magnetic steel disk. More importantly, the seed metering drive module was composed of a stepper motor with a model of 57HSE and a supporting driver with the type of HB808C. As such, the rapeseed centrifugal metering device was driven to rotate for the centrifugal force of seeding. Furthermore, a seeding control strategy was formulated to realize the uniform seed metering of sowing quantity. A seeding control model was selected to dynamically change the centrifugal speed of the centrifugal metering device via the seed metering drive module, in terms of the error between the actual and the theoretical seed metering amount. The actual seed metering number of the seed metering device was achieved within the seeding qualified range. A Bench test was carried out to determine the optimal seeding control model and operation parameters of the system. The results showed that the seeding control model was a linear model. The accuracy of the system for the seed amount detection was over 96.17%, and the optimal feedback time was 4 s. A performance test was also conducted to verify the response of the seeding amount control system to the changes in planter forward speed, the inner cone canister filling quality, the seed particle size, and the seeding plant space. The test results show that the qualified rate of seed metering regulation of the system was 92.11%, when the forward speed of the planter changes in a sinusoidal curve, indicating a better performance than that without a seeding amount control system. When the seed filling mass of the inner cone canister changed from 60 to 480 g, the seed metering errors of the control system were 9.55%, 6.91%, 6.53%, 3.89%, 4.73%, 4.2%, 2.33% and 4.98%, respectively, which were 47.68, 33.12, 3.05, 3.42, 6.06, 9.33, 11.42 and 8.55 percentage points lower than before. The metering errors of the control system for the large, medium, and small seeds were 4.70%, 3.98%, and 7.74% respectively, which were 10.79, 9.80, and 18.63 percentage points lower than before. The metering errors of the control system were 5.26%, 2.24%, and 6.53%, respectively, when the values of sowing plant spacing were 70, 100, and 130 mm, respectively. A field seeding experiment was performed on the improved system and the optimal feedback time. The results showed that the seeding error of the system was less than 10.00%, the average seeding error was 5.77%, and the qualified rate of seeding amount control was 90.68%, indicating a better seeding performance, and a much more uniform seedling emergence than before. Consequently, the new control system of seeding amount can be expected to effectively reduce the changes impact of planter forward speed, inner cone canister seed filling mass, seed particle size, and seeding plant space on the operating performance of rapeseed centrifugal metering device for the better function of uniform seeding. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Structural type of distributor normally dominates the uniform fertilizing quantity in each row and the damage rate in the fertilizing process under wide and high-speed sowing and synchronous fertilization of air-assisted planter for rapeseed and wheat. In this study, the main structural parameters of the distributor were determined according to the optimal fertilizing performance in an air-assisted applicator. The distributors with the flat top type, the inverted cone installed on the flat top type, the dome type, and the inverted cone installed on the dome type were taken as the research objects. The initial structural parameters were set: The inner diameter of delivering fertilizer tube was 82 mm. The length, width, and height of the diversion fertilizer outlet were all 30 mm. The diameter of the upper covering plate was 130 mm. The cone angle was 80° and the height of the inverted cone was 50 mm. An elastic collision model was established between the pelletized fertilizer and the main part of the distributor using Hertz theory. A Discrete Element Method (DEM) coupled with the Computational Fluid Dynamics (CFD) was selected to analyze the effects of 4-type distributors on the motion characteristics and fertilizing performance of fertilizer particles. The simulation results showed that the average values of maximum velocity and collision normal force, and the uniformity variation coefficient of each row fertilizing quantity of fertilizer particles in the distributor devices of the dome type, the flat top type, the inverted cone installed on the flat top type, and the inverted cone installed on the dome type all increased gradually. The maximum collision normal forces of fertilizer particles in the distributor of the dome type, the flat top type, the inverted cone installed on the flat top type, and the inverted cone installed on the dome type were 43.08, 62.5, 70.66, and 116.15 N, respectively, where the proportions of maximum collision normal force greater than 30 N (referring to the damage force range of pelletized fertilizer were 1.56%, 3.33%, 6.67%, and 38.89%, respectively. Furthermore, the maximum velocities of fertilizer particles in four-type distributors were 26.32, 29.14, 33.66, and 36.1 m/s, respectively, where the proportions of maximum velocity greater than 25 m/s were 0.44%, 7.78%, 9.33%, and 22.16%, respectively. The dome type distributor presented the minimum values in the maximum velocity, while the proportion of maximum velocity was greater than 25 m/s, indicating a small change in the velocity of fertilizer particles for the stable transportation of fertilizer particles. An intelligent test platform was used for planting machines to verify the fertilizing performance of an air-assisted fertilizer. The bench results indicated that there was highly consistent with the experimental and simulated changes in the maximum velocity and the maximum collision normal force of fertilizer particles in the distributor with different structural types. In a dome type distributor, the variation coefficient of uniformity in each row fertilizing quantity of particles was in the range of 6.35% to 7.52%, while the variation coefficient of stability in total fertilizing quantity was in the range of 1.53% to 1.92%, and the damage rate was in the range of 2.97% to 3.26%. Correspondingly, the dome type distributor achieved a better fertilizing performance than others. The findings can provide a sound reference to improve the structure of the distributor for precision fertilizing. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Shenyang Agricultural University is the property of Journal of Shenyang Agricultural University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The physical characteristics of rapeseed substrate block seedlings could affect its mechanical transplanting. In this paper, we measured the mechanical and biological characteristics of cubic rapeseed substrate block and link them to the safety in collecting, transporting and transplanting rapeseed substrate block seedlings. Orthogonal experiments were designed with substrate components ratio of earthworm dung, yellow brown soil, vermiculite mixture in the substrate at 1∶2∶1, 1∶1∶1 and 2∶1∶1 respectively, their associated compactness at 1.0, 1.2 and 1.4 respectively, and the concentration of boron and selenium in the solution at 0.24%, 0.27% and 0.30% respectively. We measured the mechanical characteristics of the rapeseed substrate block seeding (including its yield strength and drop loss rate) and the biological characteristics of the seedlings (including strong seedling index, substrate encapsulation degree and root robustness). The results showed that both substrate composition and compaction affected the mechanical characteristics of the rapeseed substrate block seedling, the seedling growth and root robustness at significant level or above; the concentration of boron and selenium also had a significant impact on the mechanical characteristic of the rapeseed substrate block seedlings. Substrate encapsulation degree and root robustness were both significantly affected by substrate composition ratio, compactness and concentration of the boron and selenium. The yield strength and drop loss rate of the rapeseed substrate block seedlings increased with both content and compactness of the yellow brown soil. With earthworm feces content increasing, the strong seedling index, substrate encapsulation degree and root robustness increased first followed by a decline. An increase in compaction degree and concentration of boron and selenium also resulted in an increase followed by decline in substrate encapsulation degree and root robustness. We used a comprehensive scoring method to determine the optimal combination of the seedling-raising factors by taking yield strength, strong seedling index, substrate encapsulation degree, root robustness and drop loss rate as evaluating factors with each having a weighting coefficient of 0.2. The results showed that the mechanical characteristics and the growth quality of the seedlings peaked when the ratio of all substrate components was 1∶1∶1, the compactness was 1.2 and the concentration of boron and selenium was 0.30%. A bench test results revealed that the requirements for mechanical transplanting were met when the transverse seedling pushing-speed was 20 mm/s, synchronous conveyor belt speed was 30 mm/s, the seedling picking frequency was 40 plants/min, the substrate loss rate was 2.57%, in which the feeding seedling successful rate was 90.93%. The failure of sending and collecting the seedlings could occur 1) in the process of mechanical transplanting where seedlings intertwined, resulting in an instability of the gravitational center of the seedlings, 2) in that the home-made transplanter might not be accurate enough in the bench test as there was a gap between the feeding tray and the synchronous conveyor belt, and that the installation angle of the row feeding device might bear errors. All these could result in the feeding-seedlings rate dropping to 90%. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)