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China has ranked first in the total output and use of chemical fertilizers in the world, as the increase of grain production. Generally, the single nutrient element of chemical fertilizer makes the fertilizer effect short and fast. If using for a long time, the fertilizer can cause soil hardening, soil fertility decline, even to decrease the quality of agricultural products. Alternatively, the organic fertilizer can be used to increase the soil organic matter and the permeability of soil, and thereby to ensure the high and stable yield of crops. However, the chemical fertilizer by adding more organic fertilizer behaves a high viscosity and fluidity, which makes it difficult to spread. In this study, a vertical spiral spreading device for the organic fertilizer was designed, in order to automatically crush organic fertilizer, and then to spread it wide. The specific processes were as follows: Firstly, the overall structure of device was preliminarily optimized. The vertical spiral spreading device for the organic fertilizer was mainly composed of the fertilizer spreading disc, spiral axis, beam, balance block, spiral blade, fertilizer spreading and crushing blade. The latter three were the key components of crushing organic fertilizer. Meanwhile, the fertilizer spreading and spiral blade were the key components of spreading organic fertilizer. A kinematic model of organic fertilizer in air was established to determine the influencing factors in the process of fertilizer spreading. The test factors included the rotational speed of spiral axis, inclination angle of fertilizer spreading disc, and screw pitch of spiral blade. The coefficient of variation and the fertilizer spreading width were set as the test indicators to evaluate the operation effect of the device, according to the fertilizer application standards. A field test was conducted at the Northeast Agricultural University in July, 2020. A rectangular area with the size of 10 m×8 m was set on the ground for data collection, and then the whole area was divided into many small squares with the size of 0.5 m×0.5 m for measurement. During the test, the fertilizer spreading width was first measured, and then the organic fertilizer was weighed, finally, where all test dataset was recorded. A Design-Expert 8.0.6 software was used to analyze the influence of each test factor and their interaction on each test indicator, and then a relationship was established between each test indicator and the regression equation of each test factor. An optimal combined range of all test factors was achieved via balancing the stability of the device and its economic considerations. A dataset was selected in the optimal range for the verification test: When the rotational speed of spiral axis was 385 r/min, the inclination angle of fertilizer spreading disc was 16°, and screw pitch of spiral blade was 360 mm, indicating that the coefficient of variation was 14.0%, and the fertilize spreading width was 8.1 m. The values were basically consistent with those of software calculation, indicating that can meet the national standards and the requirements of organic fertilizer application. The vertical spiral spreading device has good performance on spreading organic fertilizer, providing for a sound reference for the design and optimization of organic fertilizer spreader. [ABSTRACT FROM AUTHOR]

Mechanization level of potato planting determines the increase of potato production. However, the potato planting areas mostly distribute in the hilly and mountainous regions in the southwest China. Planting mode varies with the diverse landforms, such as lateral and vertical slopes, in small agricultural machinery, even artificially planted, particularly on the scattered plots in irregular shape. The imported potato planters have shown a high level of intelligence and precision, due to the use of some advanced technologies, such as automatic control, hydraulic system for seed supply, seeding electronic monitoring. In most planters, the sowing depth of seeding monomer can be adjusted according to the profile of monomer in large multi-row (more than 4 lines). Unfortunately, the large-scale adjustment of the sowing depth during seeding cannot be suitable for small plots and the hilly mountainous areas of China. Since small-scale potato planters suitable for hilly mountain areas mainly depend on the overall profile of ground wheel, the application of seeding monomer profile is also lacking, as well the consistency of sowing depth. Therefore, the level of mechanization for potato planting is posing a great challenge on the yield of potatoes in hilly areas. In this study, a new type of control device for sowing depth was designed in potato planter, where the structure parameters of key components include the length of profiling mechanism, traction angle, lateral width, and spring stiffness, together with the configuration of profiling wheel, and the structure of opener. The theoretical structural parameters of the device were also determined to examine the consistency of sowing depth in potato planters. A stability model of trenching depth was used to establish the motion law of profiling unit in potato planter. In the field test, the key factors were obtained for the stability of trenching depth. Test factors can be selected including the initial traction angle, spring stiffness and machine operating speed. The qualification index and variation coefficient of ditch depth were chosen as test evaluation indexes. The combination of quadratic orthogonal rotation was used to test the level range of influence factors for the stability of the sowing depth. An optimization has been performed on the effects of various factors on the ditch consistency of the uniform test device. The optimized motion parameters in the device were obtained to meet the consistency of the sowing depth. The optimum operation parameters in potato sowing can be achieved, where the ditch depth qualification index is 96.6% and the ditch depth variation coefficient is 8.9%, when the working speed is 1 m/s, the initial traction angle is 0°, and the spring stiffness is 10 N/mm. These findings can provide a new design reference to regulate the sowing depth of planters in potato seedlings. [ABSTRACT FROM AUTHOR]

Potato is one of the fourth staple food crops in China. Medium tillage operations such as loosening soil, crushing soil, soil cultivation and weeding during the early seedling and middle growth stages of potatoes have a great influence on potato yield. The main functions of mid-tillage include loosening soil, enhancing soil permeability, preserving soil moisture and drought resistance, improving soil physical properties, improving soil fertility and eliminating weeds, and mid-tillage can resist lodging and increase crop yield. Potato mid-tillage production has a large amount of work and its operation process is limited by growing crops. Therefore, it is of great significance to develop a potato mid-tillage machine with high working efficiency and good operation effect. Aiming at the problems of low soil breaking rate, weeding rate and poor soil cultivation effect of traditional hoe-shovel type cultivator under the condition of soil cohesion and compaction, a driving potato cultivator which integrates the functions of deep loosening and crushing soil, weed eradication, side deep fertilization, soil cultivation and ridging is designed in this paper, the key parts of the machine and the structure of the deep loosening shovel, soil crusher and soil cultivator are designed and analysed. On the basis of design and analysis, field experiments are carried out. The machine is mainly composed of deep loose soil device, soil conservation device, fertilization device and transmission system. Eight blade dishes are installed symmetrically on the left and right sides of the blade shaft. Each blade dish is fixed with two soil breaking blades. The length of the soil breaking blade is 242 mm, the width of the soil breaking blade is 40 mm and the thickness of the soil breaking blade is 10 mm. In order to adapt to different kind of soil conditions, the adjustment range of the subsolier is 150-250 mm, the height of the subsolier is 560 mm. The test results show that the soil breaking rate of driving-type cultivator is 95.1%, weeding rate is 96.3% and the injury rate is 1.2%, the soil bulkiness is 49.3%, and the fuel consumption is 13.2 kg/hm2, which met the relevant performance evaluation indicators. Compared with the traditional hoe-shovel type cultivator, the soil breaking rate of, weeding rate and soil bulkiness of the driving-type cultivator increase by 3.3%, 3.1% and 7.8%, injury rate and fuel consumption decrease by 1.6% and 28%. The operation effect of the driving-type cultivator has been improved significantly, exceeding the national standards and meeting the requirements of potato cultivation and agronomy. This research results can provide a reference for the development of potato cultivators. [ABSTRACT FROM AUTHOR]

In order to solve the problems such as the lower operation speed, lower precision at the present stage of China’s potato planting machine, the potato air-powered precision planter was developed in this paper. This planting machine contains fertilizer shovel, seed-metering device, wind blowing fan, potato seed box, wind suction fan, soil coverer, transmission device and land wheel. The whole machine is tracked by tractor with the power of more than 88.6 kW, and the power of fan rotary dynamic device is provided by tractor. The air-powered precision seed-metering device for potato is different from the traditional air suction device, and it has the distributed multi suction arms and at the end of each arm is installed with suction nozzles. With the rotation of seed-metering device and the working of suction fan and blowing fan, the potato can be sucked on the suction nozzles and cast into furrow in special position. As the most important structure of the seed-metering device, the sealing property of the device is very significant, and the air distribution valve of this seed-metering device is made of alumina alloy covered with porcelain. The static value cooperates with rotary value. The areas of positive pressure and negative pressure zone in static value are independent, and the negative pressure zone and the positive pressure area account for 300° and 13°, respectively. The suction nozzle contains miniature potato nozzle and conventional potato nozzle. The soil particles are cut and crashed by the edge of the shovel at the front side of the sliding-knife opener, and move along the side of opener. Some of the soil particles fall into the furrow first to create a soft furrow, and the rest of soil particles move backwards along the opener, and then cover the potato when it falls into furrow. The lower soil particles can firstly provide a better furrow situation for potato to grow. Besides, the seed-supplying device is designed to meet the needs of the transfer of potato. This potato level switch is the key part of this device. The electrical signal can be transferred from switch to motor to transfer potato seed. Fan blade is designed to meet the requirements of suction pressure. The centrifugal fan is used due to the higher efficiency. The test was implemented in Heilongjiang Academy of Agricultural Sciences and Keshan Farm in 2016 and 2017. Potato in this test was prepared by Northeast Agricultural University. Field experiments showed that the potato air-suction planter’s operating speed reached 10.2 km/h, emergence of seedling was 2-3 days earlier than potato planted by traditional planter, and the seedling rate reached 96%, indicating that the production practice of the seedlings of this device is strong. The field production test area was 200 hm2, the replay rate of the 2CMP2 potato air-powered planter was below 1%, the missing rate was below 1%, and the coefficient of variation for row spacing was less than 10%, exceeding the national standard and meeting the requirements of potato planting agronomy; the mean absolute deviation of sowing width was less than the traditional potato planter due to the use of sliding-knife opener. This air-powered planter can provide a new technology for high speed precision potato sowing and promote the potato production mechanization process in China. [ABSTRACT FROM AUTHOR]

In order to enhance seeding accuracy and seeding quality of potato, this paper analyses and tests the bouncing and casting process of the cup-belt type potato seed-metering device and the performance of flow deflector. The cup-belt type potato seed-metering devices have the problems such as the nonuniformity of plant spacing, and the higher replay rate and missing rate due to different casting angle, casting speed, casting height and potato bouncing when contacting with furrow. This paper contains the main structure and working principle of cup-belt type potato seed-metering device, and the working principle of the flow deflector is that potato drops out from seed-metering device to the deflector, and then flows along the surface. The flow deflector can reduce longitudinal distance that potato drops into furrow to make the form of potato seed in approximately one column. Flow deflector can also reduce the horizontal velocity of potato seed to decrease the distance of potato dropping into furrow. During the sowing process of seed-metering device, in addition to the contact with the flow deflector, bouncing after contact with soil will also have an influence on seeding results. In the event of seed bounce, the images of bounce process have spatial properties, a circular point uniform density of position of potato in furrow after bounce was formed, each bounce direction has the same possibility after jumping, and the displacement of potato after bounce is inconsistent. The above phenomenon will lead to a higher coefficient of variation for sowing spacing, and a lower qualified rate of seeding. The process of irregular bounce will also increase the replay rate and missing rate. This paper also obtains the main factors that influence bounce distance through the kinematic analysis of casting and bouncing process during potato seeding. The field experiment was carried out; the rotational speed of the driving pulley, the forward speed of the device, and the seed casting height were taken as the experiment factors, and the coefficient of variation of row spacing, the missing rate and the replay rate as the test indices. The test was implemented in Heilongjiang Academy of Agricultural Sciences in September, 2015 and May, 2016. Potato in this test was prepared by Northeast Agricultural University, the shape index of potato was 205.8, and the average mass of potato was 24.38 g. The experimental data were processed and optimized by software Design-Expert 8.0.6. The test result showed the primary and secondary order of influencing factors for each test index. For the coefficient of variation of row spacing, the order was the forward speed of the device, the rotational speed of driving pulley and the casting height of potato seed. For the missing rate, the order was the rotational speed of the driving pulley, the forward speed of the device and the casting height of potato seed. The order for the replay rate was as follows: The rotational speed of the driving pulley, the forward speed of the device and the casting height of potato seed. And results also showed that the coefficient of variation of row spacing was 12.5%, the missing rate was 2.21% and the replay rate was 3.56%, when the rotational speed of driving pulley was 42 r/min, the forward speed of the device was 1.2 m/s and the potato casting height was 640 mm. This device had a good seeding effect compared with the national standards. Through the performance analysis of flow deflector, the theoretical analysis of the casting progress and bouncing process of potato, and the field experiment, it has been verified that the cup-belt type potato seed-metering device which has been optimized can enhance the potato seeding accuracy and sowing effect. This research not only provides the theoretical and technical reference for improvement and optimization of potato seed-metering devices, but also other precision sowing seed-metering devices. [ABSTRACT FROM AUTHOR]

The existing zero-speed seeding technology has many disadvantages, such as being not suitable for high speed operation and the seed charge position too high. To make up for these shortcomings, a new technique of zero-speed seeding was proposed. This technology can also improve the precision of potato sowing. The positive pressure air was used as the driving force making the dropping tuber accelerated along the opposite direction of the seeding machine. In the process of falling, the horizontal velocity of tuber was zero relative to the ground. The zero-speed seeding technique was applied to sowing potato with this method. On the basis of the analysis of the throwing process, the main factors that affected the performance of zero-speed seeding were obtained, and the range of the test values of each factor was determined. These main factors were positive pressure, throw angle and rotation speed of the device. With these parameters as the experimental factors, a dual quadratic orthogonal rotational regressive test was designed. The qualified index, multiple index, missing index and coefficient of variation were selected as evaluation indices according to the national standards. The regression mathematical models between the indices and the factors were established after the test. The impacts of the factors on the evaluation indices were analyzed by using these mathematical models. The effects of positive pressure and rotation speed on the 4 indices were significant or highly significant. The throw angle had only a slightly significant effect on the coefficient of variation. When the seed metering device's rotation speed was 25-31 r/min, the main factor affecting the performance of seeding was the rotation speed. Each index value changed slightly with the change of positive pressure. When the seed metering device's rotation speed was 31-40 r/min, zero-speed seeding function of the positive pressure could effectively improve the quality of seeding. The qualified index increased and the coefficient of variation decreased with the increase of the positive pressure. At the same time, these 2 indices, the multiple index and the missing index, both had different degrees of decline. Parameters were optimized based on regression models. With the maximum qualified index, the minimum variation coefficient, the minimum multiple index and the minimum missing index as the optimization objectives, the ranges of the factors were as follows: the positive pressure of 5-15 kPa, the throw angle of 45°-75° and the rotation speed of 25-40 r/min. And taking into account the agronomic requirements of potato cultivation, the missing index was expected to be not greater than 3%. Optimization results showed that, the qualified index was 95.22%, the multiple index was 3.51%, the missing index was 1.27% and the variation coefficient was 9.43% under the condition of the positive pressure of 15 kPa, the throw angle of 57° and the rotation speed of 35 r/min. The seeding performances of developed device met the requirement of precision seeding. Results in the research give the guidance for the optimization of air-suction potato seed metering device, and provide a technical support for improving the seeding accuracy of potato and many other crops. [ABSTRACT FROM AUTHOR]

To enhance the mechanization level of potato cultivation and promote the development of potato industry, we research and design a cup-belt type seed-metering device of potato seeder. This potato seed-metering device is mainly aimed to solve many problems, including the high multiple index and missing index, heavy manual labor intensity, poor universality and other problems commonly occurring in the widely used potato seed-metering device at present. This paper introduces the main structure, the working principle and the related structural parameters of the device in detail. In this paper, we design the structure of many key components. The arrangement form of scoops on the belt, the working principle and the structure of the vibrating cleaning device, and the structure of the active belt pulley and the arch breaker are analyzed through the theoretical analysis. The parameters obtained from the theoretical analysis are used to design the cup-belt type seed-metering device. The actual utilization indicates that the seed-clearing system driven by electric motor has a simpler structure and more stable operating condition. The arch breaker increases the liquidity of the seeds and improves the filling rate. We also make a list of experiments to understand how the factors affect the performance of the potato seed-metering device and analyze the experiment results. These experiments include the overall experiment, the bench test and the field experiment. We also design an overall experiment to investigate the filling performance and the height caused by entrainment. We determine the revolving speed of the driving pulley and the number of the seeds in the seed case as the experimental factors of this experiment. The experimental results show that: when the revolving speed of the driving pulley is 33.4 r/min and the seed case is full of seeds, the average empty scoop rate is 0.33%; when the revolving speed of the driving pulley is 33.4 r/min and the seed volume is 12.5% of the seed case volume, the average height caused by entrainment is 25 cm. But even the seed case is full of potato seeds, the maximum height caused by entrainment is below the driving pulley axle. In other words, the phenomenon will not happen that the seeds are entrained into the guide pipe which causes reseeding. So when the revolving speed of the driving pulley is 33.4 r/min and the seed case is full of seeds, the working performance of the seed-metering device also meets the requirements. An orthogonal experiment is carried out in order to understand how the experimental factors affect the performance of the seed-metering device. These factors include the revolving speed of the driving pulley, the inclination of the seed-metering device and the vibration strength of the seed-clearing device. Each factor has different influence on the performance. The optimal working parameters can be concluded through these experiments and a validation experiment is carried out to verify the optimal working parameters. The experimental results show that: when the revolving speed of the driving pulley is 42 r/min, the inclination of the seed-metering device is 0° and the vibration strength of the seed-clearing device is 0.75, leading to the best performance. The qualified index is 92.6%, the multiple index is 4.5%, and the missing index is 2.9%. The field validation experiment shows that the performance of metering device under the condition can meet the potato seeder’s working performance requirements. This research provides a theoretical and technical reference for the research and design of seed-metering device of potato seeder. [ABSTRACT FROM AUTHOR]

In order to improve the problems such as uneven spreading for most fertilizer machines and the incorrect and unreasonable application of chemical fertilizer on potato, therefore, a cone disc spreader device for fertilizer spreading was designed for granular fertilizer. Inverted cone angle structure was adopted in the cone disc and two groups of vanes mounted on it. The whole organization and working principle of the device were described, and also the performance of the device was analyzed. The kinematics and dynamics analysis of granular fertilizer on spreader disc, vane and in the air were carried out. Through the above theoretical analysis, the motion models of granular fertilizer were established on the two processes mentioned above. The static bench tests were carried out in College of engineering, Northeast Agricultural University at the beginning of October 2015. The static test referred to ISO(international organization for standardization) 5690 and ASAE(American society of agricultural engineers) S341.2 in America. The test was carried out in the room, in order to reduce the effects on fertilizer spreading because of the speed of wind, the air humidity and so on. Urea was selected as experiment sample. The size guide number of urea was 2.41 mm and the density of urea was 1 265 kg/m3. Total amount of fertilizer for each test was 5 kg. The fertilizer was collected in a series of collecting boxes place on the ground in a certain way. The number of collecting boxes was 253. The collecting box had external dimensions of 200 mm×200 mm×100 mm and its thickness was 4 mm. Quadratic orthogonal rotary combination tests were carried out for the cone disc spreader device. The experimental factors of bench test included position of fertilizer export, length of vane, area of fertilizer export, pitch angle of vane in horizontal plane, rotational speed of disc. Coefficient of variation was test index. The experimental data was processed and optimized by Design-expert 8.0.6. The regression model between the test index and the factors was obtained. Meanwhile, the response surfaces were established between the coefficient of variation and the test factors in order to obtain the relationship intuitively. Test results showed that when the position of fertilizer export was(70 mm, 0, 800 mm), length of vane was 150 mm, area of fertilizer export was 2 456 mm2, pitch angle of vane in horizontal plane was 1° and rotational speed of disc was 1 090 r/min, the coefficient of variation was 5.215%. At this time, the coefficient of variation was smallest, so that the uniformity of the fertilizer was the best to meet the requirements of the application. Verification mobile test were carried out in the early November 2015. The air humidity was about 65%, the temperature was-10°--1° and the speed of wind was very small. This test was carried out in outdoor. The place that conducted the mobile test has a hard and uniform surface in College of engineering, Northeast Agricultural University. The fertilizer was also collected in a series of collecting boxes place on the ground. The number of collecting boxes was 260. Fertilizer and external dimensions of collecting boxes used in mobile test were the same with those in static test. Test results showed that the coefficient of variation for cone-type fertilizer device after optimization was 5.35% and it was consistent with optimized results. The research provides a better solution for uneven distribution of fertilizer of currently machinery in China and provides a theoretical reference for design and optimization of the cone disc distributor. [ABSTRACT FROM AUTHOR]