Ultrasonic excitation gas-liquid two-phase jet flow deep scarification fertilizer applicator

Abstract

The invention discloses an ultrasonic excitation gas-liquid two-phase jet flow deep scarification fertilizer applicator which comprises a deep scarification device, a gas-liquid two-phase jet flow device, an ultrasonic excitation device, a sensor detection device, a control system and the like. The deep scarification device is used for performing deep scarification operation, the gas-liquid two-phase jet flow device comprises a gas pressurizing device and a fertilizer pressurizing device, the gas pressurizing device is used for pressurizing gas, and the fertilizer pressurizing device is used for pressurizing liquid fertilizer and mixing the gas and the liquid fertilizer. The ultrasonic excitation device generates high-frequency vibration through an ultrasonic generator, one part is located below the gas-liquid mixer so that gas and liquid can be mixed more evenly, and the other part is located at the position of a subsoiler handle so that the subsoiler generates high-frequency vibration. The sensor detection device is used for detecting the nitrogen, phosphorus and potassium content of soil and the operation speed of the deep scarification fertilizer applicator. The control system controls the nitrogen-phosphorus-potassium fertilizer box valve to be opened according to the soil nitrogen-phosphorus-potassium content and the operation speed, and controls the frequency of the pulse controller.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural machinery devices, and particularly relates to an ultrasonic excitation gas-liquid two-phase jet subsoiling and fertilizing machine. Background Art

[0002] A subsoiling and fertilizing machine is an agricultural machine that combines the functions of subsoiling and fertilizing. Compared with traditional tillage machinery, the subsoiling and fertilizing machine effectively breaks the soil hardening layer through subsoiling operations, improves the air permeability and water permeability of the soil, thereby improving the growth environment of the roots and promoting the in-depth development of plant roots. At the same time, fertilizing and subsoiling operations are carried out synchronously, and the fertilizer can be evenly buried deep in the soil, avoiding the loss of surface fertilizer, improving the utilization rate of fertilizer, and promoting better absorption by plant roots. Subsoiling operations can also effectively improve the soil structure, loosen the soil, reduce soil compaction, and enhance the air permeability, drainage capacity and water holding capacity of the soil, which is conducive to the healthy growth of crops. The subsoiling and fertilizing machine can not only improve the physical properties of the soil, increase the fertilizer utilization rate, but also provide a better growth environment for crop roots, which helps to increase the yield and quality of crops. As a mechanized operation technology for improving soil quality and increasing crop yields, subsoiling and fertilizing technology has been increasingly widely applied and valued at home and abroad.

[0003] During the subsoiling operation of traditional subsoiling machinery, due to the direct mechanical action between the soil and the subsoiling shovel, it is necessary to overcome a large amount of soil resistance, resulting in high energy consumption of tractors or other power equipment, increasing fuel consumption and operation costs. It will also cause a large load on mechanical equipment, shorten the service life of the equipment, and increase the costs of maintenance and upkeep. In hard soil layers or soils with high viscosity, the problem of the operation efficiency of traditional subsoiling machinery is more prominent. The hard soil layer forms a large resistance to the cutting and penetration of the subsoiling shovel, resulting in a significant decrease in the operation speed, severely affecting the operation efficiency, and increasing the operation time and labor input.

[0004] During the fertilizing process of traditional fertilizing machines, it is difficult to accurately control the fertilizing amount and fertilizing position, easily causing waste and over-application of fertilizers. This not only significantly increases the fertilizer cost, but also may cause environmental problems such as soil salinization. In addition, fertilizing on the soil surface is easily affected by rainwashing and evaporation, resulting in nutrient loss and further reducing the fertilizer utilization rate. The control system of traditional fertilizing machines is relatively backward, lacking intelligent fertilizing schemes, and it is difficult to dynamically adjust the fertilizing amount according to actual needs, thus affecting the fertilizing effect and the utilization efficiency of resources. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art and provide an ultrasonic excitation gas-liquid two-phase jet subsoiling and fertilizing machine, which is provided with a gas pressurizing device, a liquid pressurizing device, an ultrasonic excitation device, a sensor detection device and a control system. The gas pressurizing device pressurizes the gas through an air compressor, the liquid pressurizing device pressurizes the liquid fertilizer through a booster pump, the ultrasonic excitation device generates ultrasonic waves through an ultrasonic generator, and the transducer converts the ultrasonic waves into high-frequency vibrations. Part of the transducers are installed below the gas-liquid mixer to make the gas-liquid mixing more uniform, and the other part of the transducers are installed at the position of the subsoiling shovel handle through a horn to increase the amplitude, so that the subsoiling shovel handle can generate high-frequency vibrations. The near-infrared spectroscopy sensor in the sensor detection device is installed at the front end of the tractor, and indirectly measures the nitrogen, phosphorus and potassium content in the soil by detecting the near-infrared spectroscopy signal in the soil. The conductivity sensor is installed at the position of the subsoiling shovel handle, and indirectly measures the nitrogen, phosphorus and potassium content in the soil by detecting the conductivity in the soil. The speed sensor real-time detects the operating speed of the tractor, controls the frequency of the pulse controller according to the operating speed, and different operating speeds match different fertilization amounts.

[0006] The present invention is realized through the following technical solutions:

[0007] An ultrasonic excitation gas-liquid two-phase jet subsoiling and fertilizing machine, comprising a frame, a subsoiling device, a traction device, a disc cutter, a gas pressurizing device, a liquid pressurizing device, an ultrasonic excitation device and a sensor detection device;

[0008] The frame is used for installing the subsoiling device, the traction device, the disc cutter, the gas pressurizing device, the liquid pressurizing device, the ultrasonic excitation device and the sensor detection device;

[0009] The subsoiling device includes a shovel handle, a shovel head and a gas-liquid pipe. The shovel head is installed at the bottom end of the shovel handle, and the gas-liquid pipe is installed at the rear end of the shovel handle;

[0010] The traction device is used for towing the subsoiling and fertilizing machine;

[0011] The disc cutter is used for cutting straws and weeds;

[0012] The gas pressurizing device is used for pressurizing the gas;

[0013] The liquid pressurizing device is used for pressurizing the liquid fertilizer;

[0014] The ultrasonic excitation device is used for generating ultrasonic waves to make the gas-liquid mixer and the subsoiling shovel handle generate high-frequency vibrations;

[0015] The sensor detection device is used for detecting the nitrogen, phosphorus and potassium content in the soil and the operating speed of the subsoiling and fertilizing machine;

[0016] The control system is used for fusing the sensor data and controlling the valve frequency of the nitrogen, phosphorus and potassium fertilizer tank;

[0017] In the above technical solution, the frame includes a front beam of the frame, a middle beam of the frame, a support plate of the frame, and a rear beam of the frame. The above-mentioned front beam of the frame, middle beam of the frame, support plate, and rear beam of the frame are welded to form the entire frame, serving as a carrier for installing a subsoiling device, a traction device, a disc cutter, a gas pressurizing device, a liquid pressurizing device, an ultrasonic excitation device, and a sensor detection device.

[0018] In the above technical solution, the number of the subsoiling devices is 3, and they are fixedly installed on the rear beam of the frame at equal intervals.

[0019] In the above technical solution, the number of the disc cutters is 3, and they are fixedly installed on the front beam of the frame at equal intervals.

[0020] In the above technical solution, the traction device includes a fixed connecting rod, two suspension connecting rods, two lower suspensions, and a bracket. The two lower suspensions that are symmetric left and right are respectively welded to the front beam of the frame. The lower ends of the two suspension connecting rods are connected to the upper ends of the lower suspensions one by one, and the upper ends of the two suspension connecting rods are connected to the upper end of the fixed connecting rod. The lower end of the fixed connecting rod is connected to the frame by the bracket.

[0021] In the above technical solution, the gas pressurizing device includes an air compressor and a hose. The air compressor pressurizes the gas, and the pressurized gas is connected to the gas-liquid mixer through the hose.

[0022] In the above technical solution, the liquid pressurizing device includes a booster pump, a nitrogen fertilizer tank, a phosphate fertilizer tank, a potassium fertilizer tank, and a pulse controller. The booster pump pressurizes the liquid fertilizer, and the pulse controller controls the valves of the nitrogen, phosphorus, and potassium fertilizer tanks.

[0023] In the above technical solution, the ultrasonic excitation device includes an ultrasonic generator, a transducer, and a horn. The ultrasonic generator generates ultrasonic waves. The transducer converts the ultrasonic waves into high-frequency vibrations, causing the gas-liquid mixer and the subsoiling shovel to generate high-frequency vibrations. The horn amplifies the amplitude.

[0024] In the above technical solution, the sensor detection device includes a near-infrared spectroscopy sensor, a conductivity sensor, and a speed sensor. The near-infrared spectroscopy sensor is installed at the front end of the tractor. This sensor utilizes the characteristics of near-infrared spectroscopy to indirectly detect the nitrogen, phosphorus, and potassium contents in the soil by analyzing the spectral absorption and reflection characteristics of organic matter and minerals in the soil. The conductivity sensor is installed at the position of the handle of the subsoiling shovel, and measures the conductivity of the soil through direct contact with the soil, indirectly calculating the contents of nutrients such as nitrogen, phosphorus, and potassium in the soil. The speed sensor is installed at the position of the frame of the subsoiling and fertilizing machine, and is used to detect the operating speed of the subsoiling and fertilizing machine in real time.

[0025] In the above technical solution, the control system includes a laptop computer, an STM32 single-chip microcomputer, and a pulse controller. The laptop computer is responsible for receiving and processing data from the near-infrared spectroscopy sensor and the conductivity sensor, and obtaining the accurate soil nitrogen, phosphorus, and potassium content through a data fusion algorithm. According to the real-time measurement results of the soil nitrogen, phosphorus, and potassium content, the laptop computer transmits the processed data to the STM32 single-chip microcomputer through a communication interface. As the control core, the STM32 single-chip microcomputer accurately controls the opening and closing states of the nitrogen, phosphorus, and potassium fertilizer tank valves based on the real-time soil nutrient data and the operation speed, ensuring the precise application of fertilizers. At the same time, the STM32 single-chip microcomputer also controls the pulse controller according to the set pulse frequency to adjust the application rate and quantity of fertilizers.

[0026] The advantages and beneficial effects of the present invention are as follows:

[0027] Through the synergistic effect of gas and liquid, the ultrasonic excitation gas-liquid two-phase jet subsoiling and fertilizing machine of the present invention can generate a stronger disturbance effect in the soil. The combination of gas and liquid can break the soil aggregate structure, improve the soil aeration and water infiltration capacity, and perform subsoiling without increasing additional mechanical pressure, reducing the soil compaction problem, protecting the soil structure, and being beneficial to crop growth. By optimizing the flow rate combination of gas and liquid, the gas-liquid two-phase jet can improve the subsoiling efficiency and reduce energy consumption during the operation.

[0028] The ultrasonic excitation gas-liquid two-phase jet subsoiling and fertilizing machine of the present invention acts on the subsoiling shovel through the high frequency and energy of ultrasonic vibration. The high-frequency vibration generated by the ultrasonic wave can effectively reduce the friction and adhesion between the subsoiling shovel and the soil, and reduce the resistance of the subsoiling operation. The ultrasonic vibration can effectively break the bonding force between soil particles, change the physical structure of the soil, and increase the looseness and porosity of the soil. The penetration effect of the ultrasonic vibration enables the subsoiling shovel to penetrate into the soil more easily. At the same time, the energy propagation of the ultrasonic wave can expand the influence range of the subsoiling area, and reduce the direct compaction effect of mechanical subsoiling on the soil through the ultrasonic excitation effect, and can also improve the speed and efficiency of the subsoiling operation.

[0029] The ultrasonic excitation gas-liquid two-phase jet subsoiling and fertilizing machine of the present invention detects the nitrogen, phosphorus, and potassium content in the soil through a near-infrared spectroscopy sensor and a conductivity sensor, and fuses the sensor data to obtain the accurate soil nitrogen, phosphorus, and potassium content. The operation speed of the subsoiling and fertilizing machine is detected in real time through a speed sensor. According to the nitrogen, phosphorus, and potassium content and the operation speed data, the control system controls the opening of the nitrogen, phosphorus, and potassium fertilizer tank valves and the frequency of the pulse controller, realizing precise fertilization according to the nitrogen, phosphorus, and potassium content lacking in the soil, and controlling different fertilization amounts according to different speeds. During the process of realizing precise fertilization, fertilization is carried out on the deep soil layer, which not only improves the nitrogen, phosphorus, and potassium content of the deep soil layer, but also avoids the waste caused by the evaporation and loss of fertilizers, and improves the fertilizer utilization efficiency. Description of the Drawings

[0030] Figure 1 This is a three-dimensional structure schematic diagram of the ultrasonic excitation gas-liquid two-phase jet subsoiling and fertilizing machine of the present invention;

[0031] Figure 2 This is an enlarged schematic diagram of the suspension mechanism in the present invention;

[0032] Figure 3 This is an enlarged schematic diagram of the subsoiling shovel in the present invention;

[0033] Figure 4 This is an enlarged schematic diagram of the gas-liquid mixer in the present invention;

[0034] Figure 5 This is an enlarged schematic diagram of the nitrogen, phosphorus and potassium fertilizer tank in the present invention;

[0035] As shown in the figure: 1 is the subsoiling shovel, 2 is the depth-limiting wheel, 3 is the fertilizer tank, 4 is the booster pump, 5 is the ultrasonic generator, 6 is the transducer, 7 is the gas-liquid mixer, 8 is the air compressor, 9 is the fixed connecting rod, 10 is the frame, 11 is the disc cutter holder, 12 is the disc cutter, 13 is the lower suspension, and 14 is the suspension connecting rod. Detailed Embodiment

[0036] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0037] An ultrasonic excitation gas-liquid two-phase jet subsoiling and fertilizing machine includes a frame 10, a subsoiling device, a traction device, a disc cutter 12, a depth-limiting wheel 2, a gas boosting device, a liquid boosting device, an ultrasonic excitation device and a sensor detection device arranged on the frame.

[0038] The frame 10 includes a front frame beam 15, a middle frame beam 17 and a rear frame beam 18. The above-mentioned front frame beam 15, middle frame beam 17 and rear frame beam 18 are welded to form the entire frame 10, serving as a carrier for installing the subsoiling device, traction device, disc cutter, depth-limiting wheel, gas boosting device, liquid boosting device, ultrasonic excitation device and sensor detection device.

[0039] The number of the subsoiling devices is 3, which are fixedly installed on the rear frame beam 18 of the frame 10 at equal intervals. Each subsoiling device includes a shovel handle 26, a shovel head 21 and a gas-liquid jet pipe 22. Among them, the shovel handle is designed based on the slip cutting principle to have a slip cutting effect, and the shovel head is a special-shaped shovel head designed based on the drag reduction principle. The shovel head is installed at the bottom end of the shovel handle through bolts.

[0040] The traction device includes a fixed connecting rod 9, two suspension connecting rods 14, two lower suspensions 13, and a bracket 16. The two lower suspensions 13, which are symmetric left and right, are welded to the front beam of the frame. The lower ends of the two suspension connecting rods 14 are respectively connected to the upper ends of the two lower suspensions 13, and the upper ends of the two suspension connecting rods 14 are connected to the upper end of the fixed connecting rod 9. The lower end of the fixed connecting rod 9 is connected to the frame by the bracket 16, and the bracket 16 is fixed to the middle end face of the rear beam of the frame by screws. During use, the two lower suspensions 13 and the upper end of the fixed connecting rod 9 are respectively connected to the tail of the tractor with pins.

[0041] The disc cutter device includes a disc cutter holder 11 and a disc cutter blade 12. The disc cutter holder 11 is installed on the front beam of the frame by U-bolts, and the disc cutter 12 is connected to the disc cutter holder 11 with bolts.

[0042] The gas pressurizing device includes an air compressor 8 and a hose. The air compressor is used to pressurize the gas and is connected to the gas-liquid mixer through the hose.

[0043] The liquid pressurizing device includes a booster pump 4, a nitrogen fertilizer tank 32, a phosphate fertilizer tank 35, a potassium fertilizer tank 34, and a solenoid valve switch 33. The booster pump is used to pressurize the liquid fertilizer, and the pulse controller controls the solenoid valve switch and the frequency of the solenoid valve switch.

[0044] The ultrasonic excitation device includes an ultrasonic generator 5, a transducer 6, a transducer 24, and a horn 25. The ultrasonic generator 5 generates ultrasonic waves. The transducer 6 is used to convert ultrasonic waves into high-frequency vibrations. Placing the transducer 6 below the gas-liquid mixer 7 makes the gas-liquid mixing more uniform. The transducer 24 is used to convert ultrasonic waves into high-frequency vibrations. Placing the transducer on the shank of the subsoiling shovel 26, a horn 25 is installed below the transducer. The horn is used to increase the amplitude, and the subsoiling shovel generates high-frequency vibrations through the transducer 24 and the horn 25.

[0045] The sensor detection device includes a near-infrared spectroscopy sensor, a conductivity sensor 23, and a speed sensor 20. The near-infrared spectroscopy sensor is placed at the front end of the tractor and is used to detect the near-infrared spectral characteristics in the soil to indirectly detect the nitrogen, phosphorus, and potassium contents in the soil. The conductivity sensor is placed on the shank of the subsoiling shovel and is used to detect the conductivity in the soil to indirectly detect the nitrogen, phosphorus, and potassium contents in the soil. The speed sensor is used to detect the operating speed of the subsoiling and fertilizing machine.

[0046] The described control system includes a laptop computer, an STM32 single-chip microcomputer, and a pulse controller. The laptop computer is responsible for receiving and processing data from the near-infrared spectroscopy sensor and the conductivity sensor, and obtaining the accurate soil nitrogen, phosphorus, and potassium content through a data fusion algorithm. According to the real-time measurement results of the soil nitrogen, phosphorus, and potassium content, the laptop computer transmits the processed data to the STM32 single-chip microcomputer through a communication interface. The STM32 single-chip microcomputer, as the control core, accurately controls the opening and closing states of the valves of the nitrogen, phosphorus, and potassium fertilizer tanks according to the real-time soil nutrient data and the operating speed, ensuring the precise application of fertilizers. At the same time, the STM32 single-chip microcomputer also controls the pulse controller according to the set pulse frequency to adjust the application rate and quantity of fertilizers.

[0047] The usage process of the present invention: During the subsoiling operation, the gas is pressurized by a gas pressurization device, the nitrogen, phosphorus, and potassium liquid fertilizer is pressurized by a liquid pressurization device, and the gas and liquid are mixed by a gas-liquid mixer. The ultrasonic generator generates ultrasonic waves, the transducer converts the ultrasonic waves into high-frequency vibrations, and the amplitude is amplified by a horn to make the gas-liquid mixture uniform and make the subsoiling shovel generate high-frequency vibrations. The near-infrared spectroscopy sensor and the conductivity sensor detect the nitrogen, phosphorus, and potassium content in the soil, the speed sensor detects the operating speed of the subsoiling fertilizer applicator, and the control system controls the opening of the valves of the nitrogen, phosphorus, and potassium fertilizer tanks according to the soil nitrogen, phosphorus, and potassium content data and the speed sensor data, and controls the frequency of the pulse controller to realize the subsoiling fertilization operation.

[0048] For ease of explanation, the above-described embodiments use spatial relative terms such as "upper", "lower", "left", "right", etc. to describe the positional relationship of a certain element in the figure relative to other elements. It should be understood that in addition to the orientations shown in the figure, the spatial terms are intended to include different orientations during the use or operation of the device. For example, if the device in the figure is inverted, the original positional relationship described as being "above" or "below" other elements will be changed to "below" or "above". The device can be rotated in other ways.

[0049] It should be noted that: The above-described embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Those of ordinary skill in the art can modify the technical solutions in the foregoing embodiments without departing from the core of the present invention, and can make other different forms of changes based on the above description. However, it should be noted that any modifications, equivalent replacements, and improvements, etc. do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention and should all be included within the protection scope of the claims of the present invention.

Claims

1. An ultrasonically excited gas-liquid two-phase jet deep loosening fertilization machine, characterized in that: It includes a frame, a traction device, a deep loosening device, a disc knife, an air compressor, a booster pump, a fertilizer box, a gas-liquid mixer, an ultrasonic generator, a transducer, a speed sensor, a near-infrared spectrum sensor, and a conductivity sensor; the frame includes a front beam, a middle beam, a support plate, and a rear beam; the deep loosening device includes a shovel handle, a shovel head, a gas-liquid pipe, and a nozzle; the traction device is used to be connected to a tractor; the disc knife is used to cut straw and weeds; the air compressor is used to pressurize the air; the booster pump is used to pressurize the liquid fertilizer; the gas-liquid mixer is used to mix the air and the liquid fertilizer evenly; the ultrasonic generator is used to generate ultrasonic waves; the transducer is used to convert ultrasonic waves into high-frequency vibrations; and the sensor is used to detect the nitrogen, phosphorus, and potassium content of the soil and the operating speed.

2. The ultrasonically excited gas-liquid two-phase jet deep tillage fertilization machine according to claim 1 is characterized in that: The frame comprises a frame front beam, a frame middle beam, a frame support plate, and a frame rear beam. The frame front beam, frame middle beam, support plate, and frame rear beam are welded together to form the entire frame.

3. The ultrasonically excited gas-liquid two-phase jet deep tillage fertilization machine according to claim 1 is characterized in that: The number of the deep loosening devices is 3, which are fixedly installed on the frame at equal intervals, and the number of the disc cutters is 3, which are fixedly installed on the frame at equal intervals.

4. The ultrasonically excited gas-liquid two-phase jet deep tillage fertilization machine according to claim 1 is characterized in that: The number of the deep plowing shovels is 3, which are fixedly installed on the frame at equal intervals. The gas-liquid pipe is located behind the deep plowing shovel, and the nozzle is located below the deep plowing shovel and connected to the gas-liquid pipe.

5. The ultrasonically excited gas-liquid two-phase jet deep tillage fertilization machine according to claim 1 is characterized in that: The air compressor is used to pressurize the gas and is connected to the gas-liquid mixer through a hose.

6. The ultrasonically excited gas-liquid two-phase jet deep tillage fertilization machine according to claim 1, characterized in that: The booster pump is used to boost the pressure of the liquid fertilizer in the fertilizer box and is connected to the gas-liquid mixer through a hose.

7. The ultrasonically excited gas-liquid two-phase jet deep tillage fertilization machine according to claim 1 is characterized in that: The gas-liquid mixer is used to evenly mix high-pressure air and high-pressure liquid fertilizer, and the outlet of the gas-liquid mixer is connected to the gas-liquid pipe of the deep tillage shovel.

8. The ultrasonically excited gas-liquid two-phase jet deep tillage fertilization machine according to claim 1 is characterized in that: The ultrasonic generator is used to generate ultrasonic waves, which are connected to the transducer to generate high-frequency vibrations. A part of the transducer is installed under the gas-liquid mixer to make the gas-liquid mixing more uniform, and the other part is installed at the handle of the deep plowing shovel and amplifies the amplitude through the amplitude rod, so that the deep plowing shovel generates high-frequency vibrations.

9. The ultrasonically excited gas-liquid two-phase jet deep tillage fertilization machine according to claim 1, characterized in that: The sensor is used to detect the nitrogen, phosphorus and potassium content in the soil. The near-infrared spectrum sensor is installed at the front end of the tractor to detect the nitrogen, phosphorus and potassium content in the soil. The conductivity sensor is installed at the deep tillage shovel handle to detect the nitrogen, phosphorus and potassium content in the soil. The soil nitrogen, phosphorus and potassium content data detected by the conductivity sensor and the near-infrared spectrum sensor are fused, and the speed sensor is used to detect the operating speed in real time.

10. The ultrasonically excited gas-liquid two-phase jet deep tillage fertilization machine according to claim 1, characterized in that: The control system comprises a laptop computer, an STM32 single-chip microcomputer and a pulse controller. The laptop computer is responsible for receiving and processing data from a near-infrared spectrum sensor and a conductivity sensor, and obtaining accurate soil nitrogen, phosphorus and potassium content through a data fusion algorithm. According to the real-time measurement result of the soil nitrogen, phosphorus and potassium content, the laptop computer transmits the processed data to the STM32 single-chip microcomputer through a communication interface. The STM32 single-chip microcomputer serves as a control core and accurately controls the switch state of the nitrogen, phosphorus and potassium fertilizer box valve according to real-time soil nutrient data and operation speed. At the same time, the STM32 single-chip microcomputer also controls the pulse controller according to the set pulse frequency to adjust the application rate and amount of the fertilizer.

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