A soil organic matter in-situ detection system and method for variable rate seeding

Abstract

The application provides a soil organic matter in-situ detection system and method for variable rate seeding, and the soil organic matter high-temperature excitation in-situ detection system comprises a rack, a linear motion mechanism, a secondary filtering and cooling device, a dilution device, a carbon dioxide detection module, a pneumatic module and a control module are installed on the rack, a heating device is installed on the linear motion mechanism, a primary filtering device is installed on the side of the heating device, the pneumatic module comprises an air pump and a pneumatic pipe, the air pump is installed on the rack, and the pneumatic pipe is sequentially connected with the secondary filtering and cooling device, the air pump, the dilution device and the carbon dioxide detection module.

Description

Technical Field

[0001] This invention patent belongs to the field of soil testing technology. Specifically, it relates to an in-situ soil organic matter testing system and method for variable seeding. Background Technology

[0002] Soil organic matter content is an important indicator for assessing soil fertility and a key factor in crop emergence and growth. Since soil organic matter content varies across different regions, the required seeding rate also differs. Therefore, it is necessary to measure soil organic matter content in situ during sowing and adjust the seed metering device's seeding rate in real time based on this information to achieve precision sowing.

[0003] However, traditional methods for detecting soil organic matter have some limitations. For example, traditional laboratory analysis requires a significant amount of time and resources, making it unsuitable for real-time monitoring and remote surveillance. Furthermore, some field testing methods involve cumbersome soil sample processing and preparation, which can easily introduce interfering factors and affect the accuracy of the test results.

[0004] In conclusion, developing an efficient, real-time, and accurate soil organic matter detection system to meet the needs of modern agriculture and environmental protection has become an urgent technical problem to be solved. Summary of the Invention

[0005] To overcome a series of defects in the existing technology, the present invention aims to provide an in-situ soil organic matter detection system for variable seeding, which includes a frame 27. The frame 27 supports and installs a linear motion mechanism, a secondary filtration and cooling device, a dilution device, a carbon dioxide detection module, a pneumatic module, and a control module. A heating device is installed on the linear motion mechanism, and a primary filtration device is installed on the side of the heating device. The pneumatic module includes an air pump 16 and a pneumatic air pipe 28. The air pump 16 is installed on the frame 27, and the pneumatic air pipe 28 is connected in series with the secondary filtration and cooling device, the air pump 16, the dilution device, and the carbon dioxide detection module.

[0006] Preferably, the heating device includes a high-temperature probe 1, a gas guide chamber 2, a top cover 3, and a heat insulation plate 4. The gas guide chamber 2 and the top cover 3 are connected by bolts to form a gas guide chamber cavity. The high-temperature probe 1 is located inside the gas guide chamber cavity and is connected to the top cover 3 by nuts and washers. The heat insulation plate 4 is fixed to the side of the top cover 3.

[0007] Preferably, the linear motion mechanism includes a lead screw box 6, a trapezoidal lead screw 7, a lead screw nut, a slide rail, a heating device fixing plate 5, a coupling, a brushless motor 9, and a motor bracket 8. The trapezoidal lead screw 7 is connected to the lead screw box 6 via bearings. The top end of the trapezoidal lead screw 7 is connected to the brushless motor 9 via a coupling. The lead screw nut is placed on the trapezoidal lead screw 7. The heating device fixing plate 5 is fixed to the lead screw nut and the slide rail via bolts. The brushless motor 9 is fixed to the end of the lead screw box 6 via the motor bracket 8.

[0008] Preferably, the primary filtration device includes a first filter chamber and a second filter chamber. The first filter chamber and the second filter chamber are fixed together by bolts to form a primary filtration chamber 11. The end of the first filter chamber is threaded to be connected to the heating device. A pagoda-shaped pneumatic connector 10 is threaded to the end of the second filter chamber to facilitate the installation of the pneumatic air pipe 28. The interior of the primary filtration chamber 11 is fixed with a filter screen for filtering dust by four fixing blocks.

[0009] Preferably, the secondary filtration and cooling device includes a semiconductor refrigeration chip 12, a cooling chamber 13, a cooling fan, and a heat sink 15. The cooling surface of the semiconductor refrigeration chip 12 is installed outside the cooling chamber 13, and the heat sink and cooling fan are installed on the heat dissipation surface of the semiconductor refrigeration chip 12. A top cover 1 and a top cover 2 are respectively installed on both sides of the cooling chamber 13. Filter screens are fixed inside the top cover 1 and the top cover 2 by snap rings. Pneumatic pagoda connectors for easy installation of pneumatic air pipes 28 are installed at both ends of the top cover 1 and the top cover 2, and sealing gaskets are placed thereon. Sealing rings are used on both sides of the cooling chamber 13 to prevent gas from escaping, so as to form a closed cooling chamber.

[0010] Preferably, the dilution device includes a dilution chamber 17, which is integrally formed by 3D printing. Pneumatic pagoda connectors are installed on both sides of the dilution chamber 17 to facilitate the installation of pneumatic air pipes 28. Sealing gaskets are placed at the connection between the pneumatic pagoda connectors and the dilution chamber 17.

[0011] Preferably, the carbon dioxide detection module includes a carbon dioxide sensor 18, a circuit board 20, and a sensor air chamber 19. The carbon dioxide sensor 18 is installed in the sensor air chamber 19, which is mounted on a frame 27. Pneumatic pagoda connectors are installed on both sides of the sensor air chamber 19 to facilitate the installation of pneumatic air pipes 28. Sealing gaskets are placed at the connection points between the pneumatic pagoda connectors and the sensor air chamber 19. The carbon dioxide sensor 18 is powered and transmits data through the circuit board 20.

[0012] Preferably, the control module includes a main controller 21, a relay 23, a display 26, a power supply 24, a transformer 29, a motor controller, and a human-machine interface 25. The power supply 24 uses a 24V power supply, and the transformer 29 is used to step down the power supply for the high-temperature probe 1, the semiconductor cooling chip 12, and the carbon dioxide sensor 18. The main controller 21 is a Raspberry Pi 4B, and the display 26 is used as the display terminal of the main controller 21. The human-machine interface 25 is designed and used on the main controller 21 using Qt Creator 5.

[0013] The purpose of this application is also to provide a method for in-situ detection of soil organic matter in variable seeding, including the following steps.

[0014] According to the research needs, the temperature of the high temperature probe 1 is determined and the high temperature probe 1 is installed on the heating device fixing plate 5 on the linear motion mechanism.

[0015] Upon arrival at the detection area, the main controller 21 is activated. After the high-temperature probe 1 and the carbon dioxide sensor 18 have finished preheating, the air pump 16 and the semiconductor cooling chip 12 are turned on. The high-temperature probe 1 is inserted into the soil through the linear motion mechanism, so that the air chamber 2 is close to the soil surface. A small amount of organic matter in the high-temperature soil is oxidized into carbon dioxide.

[0016] Under the action of the air pump 16, carbon dioxide gas is sequentially transmitted through the air guide chamber 2, the primary filter device, the secondary filter and cooling device, the air pump 16, and the dilution device to the carbon dioxide sensor 18, thereby obtaining the constantly changing carbon dioxide concentration value.

[0017] The carbon dioxide concentration value acquired by the carbon dioxide sensor 18 is transmitted to the main controller 21 via serial communication. The main controller 21 performs calculations using a corresponding algorithm, and the final soil organic matter detection result is displayed on the human-machine interface 25 and saved in real time in an EXCEL spreadsheet for easy use later.

[0018] Compared with the prior art, the present invention has the following beneficial effects.

[0019] This application utilizes the principle of in-situ rapid detection of CO2 generated from soil organic matter through high-temperature activation. It incorporates a multi-stage filtration and dust removal system and a gas dilution system, along with an automatic control and data processing module. This enables precise and real-time monitoring of soil organic matter. The system is portable, compact, easy to operate, and pollution-free during the detection process. It not only meets the needs of modern agriculture for refined soil management and enables precision fertilization but also has economic value for widespread application. It is an advanced detection technology that integrates environmental protection, efficiency, and accuracy, and can provide strong technical support for related fields. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the front end of a soil organic matter in-situ detection system for variable seeding disclosed in this invention.

[0021] Figure 2 This is a schematic diagram of the back end of a soil organic matter in-situ detection system for variable seeding disclosed in this invention.

[0022] Figure 3 This is a schematic diagram of the heating device in a soil organic matter in-situ detection system for variable seeding disclosed in this invention.

[0023] Figure 4 This is a schematic diagram of the gas path in an in-situ soil organic matter detection system for variable seeding disclosed in this invention.

[0024] Figure 5 This is a flowchart illustrating the principle of an in-situ soil organic matter detection system for variable seeding disclosed in this invention.

[0025] Figure 6 This is a control principle diagram of an in-situ soil organic matter detection system for variable seeding disclosed in this invention.

[0026] The attached diagram is labeled as follows: 1 - High-temperature probe; 2 - Air chamber; 3 - Top cover; 4 - Heat insulation plate; 5 - Heating device mounting plate; 6 - Lead screw box; 7 - Trapezoidal lead screw; 8 - Motor bracket; 9 - Brushless motor; 10 - Pagoda-type pneumatic connector; 11 - Primary filter chamber; 12 - Semiconductor cooling chip; 13 - Cooling chamber; 14 - Secondary filter top cover; 15 - Cooling fan and heat sink; 16 - Air pump; 17 - Dilution chamber; 18 - Carbon dioxide sensor; 19 - Sensor air chamber; 20 - Circuit board; 21 - Main controller; 22 - CAN HAT; 23 - Relay; 24 - Power supply; 25 - Human-machine interface; 26 - Display; 27 - Frame; 28 - Pneumatic air pipe; 29 - Transformer; 30 - Soil. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some embodiments of this invention, but not all embodiments.

[0028] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] The embodiments and directional terms described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] In a broad embodiment of the present invention, a soil organic matter in-situ detection system for variable seeding includes a frame 27, on which a linear motion mechanism, a secondary filtration and cooling device, a dilution device, a carbon dioxide detection module, a pneumatic module, and a control module are mounted. A heating device is mounted on the linear motion mechanism, and a primary filtration device is mounted on the side of the heating device. The pneumatic module includes an air pump 16 and a pneumatic air pipe 28. The air pump 16 is mounted on the frame 27, and the pneumatic air pipe 28 is connected in series with the secondary filtration and cooling device, the air pump 16, the dilution device, and the carbon dioxide detection module.

[0031] Preferably, the heating device includes a high-temperature probe 1, a gas guide chamber 2, a top cover 3, and a heat insulation plate 4. The gas guide chamber 2 and the top cover 3 are connected by bolts to form a gas guide chamber cavity. The high-temperature probe 1 is located inside the gas guide chamber cavity and is connected to the top cover 3 by nuts and washers. The heat insulation plate 4 is fixed to the side of the top cover 3.

[0032] Preferably, the linear motion mechanism includes a lead screw box 6, a trapezoidal lead screw 7, a lead screw nut, a slide rail, a heating device fixing plate 5, a coupling, a brushless motor 9, and a motor bracket 8. The trapezoidal lead screw 7 is connected to the lead screw box 6 via bearings. The top end of the trapezoidal lead screw 7 is connected to the brushless motor 9 via a coupling. The lead screw nut is placed on the trapezoidal lead screw 7. The heating device fixing plate 5 is fixed to the lead screw nut and the slide rail via bolts. The brushless motor 9 is fixed to the end of the lead screw box 6 via the motor bracket 8.

[0033] Preferably, the primary filtration device includes a first filter chamber and a second filter chamber. The first filter chamber and the second filter chamber are fixed together by bolts to form a primary filtration chamber 11. The end of the first filter chamber is threaded to be connected to the heating device. A pagoda-shaped pneumatic connector 10 is threaded to the end of the second filter chamber to facilitate the installation of the pneumatic air pipe 28. The interior of the primary filtration chamber 11 is fixed with a filter screen for filtering dust by four fixing blocks.

[0034] Preferably, the secondary filtration and cooling device includes a semiconductor refrigeration chip 12, a cooling chamber 13, a cooling fan, and a heat sink 15. The cooling surface of the semiconductor refrigeration chip 12 is installed outside the cooling chamber 13, and the heat sink and cooling fan are installed on the heat dissipation surface of the semiconductor refrigeration chip 12. A top cover 1 and a top cover 2 are respectively installed on both sides of the cooling chamber 13. Filter screens are fixed inside the top cover 1 and the top cover 2 by snap rings. Pneumatic pagoda connectors for easy installation of pneumatic air pipes 28 are installed at both ends of the top cover 1 and the top cover 2, and sealing gaskets are placed thereon. Sealing rings are used on both sides of the cooling chamber 13 to prevent gas from escaping, so as to form a closed cooling chamber.

[0035] Preferably, the dilution device includes a dilution chamber 17, which is integrally formed by 3D printing. Pneumatic pagoda connectors are installed on both sides of the dilution chamber 17 to facilitate the installation of pneumatic air pipes 28. Sealing gaskets are placed at the connection between the pneumatic pagoda connectors and the dilution chamber 17.

[0036] Preferably, the carbon dioxide detection module includes a carbon dioxide sensor 18, a circuit board 20, and a sensor air chamber 19. The carbon dioxide sensor 18 is installed in the sensor air chamber 19, which is mounted on a frame 27. Pneumatic pagoda connectors are installed on both sides of the sensor air chamber 19 to facilitate the installation of pneumatic air pipes 28. Sealing gaskets are placed at the connection points between the pneumatic pagoda connectors and the sensor air chamber 19. The carbon dioxide sensor 18 is powered and transmits data through the circuit board 20.

[0037] Preferably, the control module includes a main controller 21, a relay 23, a display 26, a power supply 24, a transformer 29, a motor controller, and a human-machine interface 25. The power supply 24 uses a 24V power supply, and the transformer 29 is used to step down the power supply for the high-temperature probe 1, the semiconductor cooling chip 12, and the carbon dioxide sensor 18. The main controller 21 is a Raspberry Pi 4B, and the display 26 is used as the display terminal of the main controller 21. The human-machine interface 25 is designed and used on the main controller 21 using Qt Creator 5.

[0038] The purpose of this application is also to provide a method for in-situ detection of soil organic matter in variable seeding, including the following steps.

[0039] According to the research needs, the temperature of the high temperature probe 1 is determined and the high temperature probe 1 is installed on the heating device fixing plate 5 on the linear motion mechanism.

[0040] Upon arrival at the detection area, the main controller 21 is activated. After the high-temperature probe 1 and the carbon dioxide sensor 18 have finished preheating, the air pump 16 and the semiconductor cooling chip 12 are turned on. The high-temperature probe 1 is inserted into the soil through the linear motion mechanism, so that the air chamber 2 is close to the soil surface. A small amount of organic matter in the high-temperature soil is oxidized into carbon dioxide.

[0041] Under the action of the air pump 16, carbon dioxide gas is sequentially transmitted through the air guide chamber 2, the primary filter device, the secondary filter and cooling device, the air pump 16, and the dilution device to the carbon dioxide detection module, thereby obtaining the constantly changing carbon dioxide concentration value through the carbon dioxide sensor 18.

[0042] The carbon dioxide concentration value acquired by the carbon dioxide sensor 18 is transmitted to the main controller 21 via serial communication. The main controller 21 performs calculations using a corresponding algorithm, and the final soil organic matter detection result is displayed on the human-machine interface 25 and saved in real time in an EXCEL spreadsheet for easy use later.

[0043] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, and the present invention will be further described in detail.

[0044] like Figure 1-6 As shown, a soil organic matter in-situ detection system and method based on the high-temperature excitation principle is described. The soil is heated and oxidized by a high-temperature probe 1, causing the organic matter in it to be oxidized into carbon dioxide. The generated carbon dioxide is cooled, filtered, and diluted by a gas pump 16 through a filter device, a cooling device, and a dilution device. Finally, the carbon dioxide gas concentration is detected in real time by a carbon dioxide sensor 18. Then, the main controller 21 calculates the soil organic matter content, realizing in-situ detection of soil organic matter.

[0045] The soil organic matter in-situ detection system based on the high-temperature excitation principle includes a frame 27. The frame 27 supports and installs a linear motion mechanism, a primary filtration device, a secondary filtration and cooling device, a dilution device, a carbon dioxide detection module, a pneumatic module, and a control module. The linear motion mechanism is equipped with a heating device. The pneumatic module includes an air pump 16 and a pneumatic air pipe 28. The air pump 16 is mounted on the frame 27. The pneumatic air pipe 28 is connected in series with the primary filtration device, the secondary filtration and cooling device, the air pump 16, the dilution device, and the carbon dioxide detection module.

[0046] The heating device includes a high-temperature probe 1, a gas guide chamber 2, a top cover 3, and a heat insulation plate 4. The gas guide chamber 2 and the top cover 3 are connected by bolts to form a gas guide chamber cavity. The high-temperature probe 1 is located inside the gas guide chamber cavity and is connected to the top cover 3 by nuts and washers. The heat insulation plate 4 is fixed to the side of the top cover 3.

[0047] The linear motion mechanism includes a lead screw box 6, a trapezoidal lead screw 7, a lead screw nut, a slide rail, a heating device fixing plate 5, a coupling, a brushless motor 9, and a motor bracket 8. The trapezoidal lead screw 7 is connected to the lead screw box 6 via bearings. The top end of the trapezoidal lead screw 7 is connected to the brushless motor 9 via a coupling. The lead screw nut is placed on the trapezoidal lead screw 7. The heating device fixing plate 5 is fixed to the lead screw nut and the slide rail with bolts. The brushless motor 9 is fixed to the end of the lead screw box 6 via the motor bracket 8.

[0048] The primary filtration device includes a first filter chamber and a second filter chamber. The first filter chamber and the second filter chamber are fixed together by bolts to form a primary filtration chamber 11. The end of the first filter chamber is threaded to be connected to the heating device. A pagoda-shaped pneumatic connector 10 is threaded to the end of the second filter chamber to facilitate the installation of the pneumatic air pipe 28. Inside the primary filtration chamber 11, a filter screen for filtering dust is fixed by four fixing blocks.

[0049] The secondary filtration and cooling device includes a semiconductor refrigeration chip 12, a cooling chamber 13, a cooling fan, and a heat sink 15. The cooling surface of the semiconductor refrigeration chip 12 is installed outside the cooling chamber 13, and the heat sink and cooling fan are installed on the heat dissipation surface of the semiconductor refrigeration chip 12. A top cover 1 and a top cover 2 are installed on both sides of the cooling chamber 13, respectively. Filter screens are fixed inside the top cover 1 and the top cover 2 by snap rings. Pneumatic pagoda connectors for easy installation of pneumatic air pipes 28 are installed at both ends of the top cover 1 and the top cover 2, and sealing gaskets are placed therein. Sealing rings are used on both sides of the cooling chamber 13 to prevent gas from escaping in order to form a sealed cooling chamber.

[0050] The dilution device includes a dilution chamber 17, which is integrally formed by 3D printing. Pneumatic pagoda connectors are installed on both sides of the dilution chamber 17 to facilitate the installation of pneumatic air pipes 28. Sealing gaskets are placed at the connection between the pneumatic pagoda connectors and the dilution chamber 17.

[0051] The carbon dioxide detection module includes a carbon dioxide sensor 18, a circuit board 20, and a sensor air chamber 19. The carbon dioxide sensor 18 is installed in the sensor air chamber 19, which is mounted on a frame 27. Pneumatic pagoda connectors are installed on both sides of the sensor air chamber 19 to facilitate the installation of pneumatic air pipes 28. Sealing gaskets are placed at the connection points between the pneumatic pagoda connectors and the sensor air chamber 19. The carbon dioxide sensor 18 is powered and transmits data through the circuit board 20.

[0052] The control module includes a main controller 21, a relay 23, a display 26, a power supply 24, a transformer 29, a motor controller, and a human-machine interface 25. The power supply 24 uses a 24V power supply, and the transformer 29 is used to step down the power supply for the high-temperature probe 1, the semiconductor cooling chip 12, and the carbon dioxide sensor 18. The main controller 21 is a Raspberry Pi 4B, and the display 26 is used as the display terminal of the main controller 21. The human-machine interface 25 is designed and used on the main controller 21 using Qt Creator 5.

[0053] The system structure and functions are as follows.

[0054] The linear motion mechanism is mounted on the frame 27, and the heating device is mounted on the linear motion mechanism. The heat insulation plate 4 of the heating device is connected to the heating device fixing plate 5 of the linear motion mechanism by bolts. The function of the heat insulation plate 4 is to prevent heat from being transferred to the linear motion mechanism so as not to damage the parts on the linear motion mechanism. The control module uses PID control to make the heating device move to the designated position. After the high temperature probe 1 is preheated to the designated temperature, it is inserted into the soil. The gas to be tested is then drawn into the air guide chamber by the air pump 16 and then enters the first-stage filter device at the side along the air path.

[0055] The primary filtration device is fixed to the side of the heating device via a threaded connection to achieve initial filtration of the gas to be tested and prevent dust from affecting the detection accuracy of the carbon dioxide sensor 18.

[0056] The secondary filtration and cooling device is placed on the frame 27 and is used to perform secondary filtration of dust in the gas to be measured and to reduce the temperature of the high-temperature gas by cooling means to meet the temperature requirements of the carbon dioxide sensor 18 for the gas to be measured.

[0057] The dilution device is used to dilute the carbon dioxide concentration in the gas being tested, when the soil organic matter content is greater than 40 g·kg⁻¹. -1 At times, the concentration of carbon dioxide generated exceeds the detection range of the carbon dioxide sensor 18, so a dilution device is needed to dilute the gas. Simultaneously, the condensate produced by the secondary filtration and cooling device mixes with the filtered dust to form muddy water; the dilution device also prevents this muddy water from entering the sensor detection module.

[0058] The carbon dioxide sensor 18 is powered and transmits data via circuit board 20. The digital signal output by the carbon dioxide sensor 18 is transmitted to the main controller 21 via circuit board 20. At the same time, the power supply 24 also provides step-down power to the carbon dioxide sensor 18 via circuit board 20. Circuit board 20 transmits data with the main controller 21 via serial communication.

[0059] In the pneumatic module, in order to maximize the use of the suction power of the air pump 16 and reduce the intake of dust, the arrangement order of the devices in the air circuit is as follows: heating device, primary filter device, secondary filter and cooling device, dilution device, sensor detection module, and air pump 16.

[0060] In the control module, a Raspberry Pi 4 (Raspberry Pi 4B) is used as the main controller 21. A MicroSnow RS485 CANHAT22 is used to convert the Raspberry Pi 4's SPI communication to CAN communication for use with relay 23 and brushless motor 9. A USB-to-TTL module is used to convert the Raspberry Pi 4's USB interface to a serial communication interface for use with carbon dioxide sensor 18. Both brushless motor 9 and relay 23 are controlled via CAN communication. Brushless motor 9 uses a position loop PID control for positioning, ensuring it stably reaches the expected position. Relay 23 controls the on / off state of high-temperature probe 1, thermoelectric cooler 12, and air pump 16. A human-machine interface 25 is designed using C++ in Qt Creator 5 software on the Raspberry Pi 4. This interface controls the on / off state of high-temperature probe 1, thermoelectric cooler 12, and air pump 16, and also controls the heating device to reach its designated working position. Simultaneously, it acquires real-time concentration data from carbon dioxide sensor 18, processes it using algorithms, outputs soil organic matter data on the screen, and stores it in an Excel spreadsheet in real-time.

[0061] The principle of the detection method is as follows.

[0062] To detect organic matter in soils of different textures, a high-temperature excitation principle is used. This principle involves inserting a high-temperature object into the soil (30), causing the organic carbon in the soil to decompose and produce a large amount of carbon dioxide. The concentration of carbon dioxide is then used to predict the organic carbon content. The higher the organic carbon content in the soil (30), the higher the concentration of carbon dioxide produced. Furthermore, there is a linear positive correlation between organic carbon and organic matter content; the organic carbon content multiplied by the van Bemmelen factor equals the organic matter content. To prevent inorganic carbon in the soil (30) from interfering with the detection accuracy, the temperature of the high-temperature probe (1) needs to be controlled below 650 degrees Celsius.

[0063] The system workflow is as follows.

[0064] When detecting soil organic matter content, the high-temperature probe 1 installed on the linear motion mechanism is first powered on to raise its temperature to 500℃, while the carbon dioxide sensor 18 is preheated. After the high-temperature probe 1 and the carbon dioxide sensor 18 are preheated, the linear motion mechanism inserts the high-temperature probe 1, which has reached a temperature of 500℃, into the soil 30. The high temperature oxidizes the soil organic matter into carbon dioxide. At this time, the gas delivery chamber is in close contact with the surface of the soil 30 to prevent gas from escaping. The air pump 16 transmits the generated carbon dioxide gas sequentially through the gas delivery chamber 2, the primary filter, the secondary filter and cooling device, the air pump 16, and the dilution device to the inside of the carbon dioxide sensor 18, thereby obtaining the constantly changing carbon dioxide concentration value. The carbon dioxide concentration value obtained by the carbon dioxide sensor 18 is transmitted to the control module via serial communication for corresponding data calculation. Finally, the soil organic matter detection result is displayed on the display 26.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A soil organic matter in-situ detection system for variable rate seeding comprising a frame (27) characterised in that, The linear motion mechanism is installed with a heating device, and a primary filtering device is installed on the side of the heating device; the pneumatic module comprises a gas pump (16) and a pneumatic air pipe (28), the gas pump (16) is installed on the rack (27), and the pneumatic air pipe (28) is sequentially connected with the secondary filtering and cooling device, the gas pump (16), the dilution device and the carbon dioxide detection module; The heating device comprises a high-temperature probe (1), a gas guide warehouse (2), a top cover (3) and a heat insulation plate (4), the gas guide warehouse (2) and the top cover (3) are connected by bolts to form a gas guide chamber, the high-temperature probe (1) is inside the gas guide chamber and is connected with the top cover (3) through a nut and a gasket, and the heat insulation plate (4) is fixed on the side of the top cover (3); The linear motion mechanism comprises a lead screw box (6), a trapezoidal lead screw (7), a lead screw nut, a sliding rail, a heating device fixing plate (5), a coupling, a brushless motor (9) and a motor support (8), the trapezoidal lead screw (7) is connected in the lead screw box (6) through bearings, the top end of the trapezoidal lead screw (7) is connected with the brushless motor (9) through the coupling, the lead screw nut is placed on the trapezoidal lead screw (7), the heating device fixing plate (5) is fixed with the lead screw nut and the sliding rail through bolts, and the brushless motor (9) is fixed at the end of the lead screw box (6) through the motor support (8); The primary filtering device is fixed on the side end of the heating device through thread connection, so as to realize the primary filtration of the measured gas, the primary filtering device comprises filter bin one and filter bin two, the filter bin one and the filter bin two are fixed by bolts to form a primary filtering chamber (11), the end of the filter bin one is provided with threads to be connected with the heating device, a pagoda-shaped pneumatic connector (10) is connected with the end of the filter bin two through threads to facilitate the installation of the pneumatic air pipe (28), and the inside of the primary filtering chamber (11) is fixed with a filter screen for filtering dust through four fixing blocks; The secondary filtering and cooling device is used for secondary filtering of dust in the measured gas and reducing the temperature of the high-temperature gas, the secondary filtering and cooling device comprises a semiconductor refrigerating sheet (12), a cooling chamber (13) and a cooling fan and a cooling fin (15), the refrigerating surface of the semiconductor refrigerating sheet (12) is installed outside the cooling chamber (13), the cooling fin and the cooling fan are installed on the heat dissipation surface of the semiconductor refrigerating sheet (12), the two sides of the cooling chamber (13) are respectively provided with a top cover one and a top cover two, the inside of the top cover one and the top cover two is fixed with a filter screen through a snap spring, the two ends of the top cover one and the top cover two are provided with a pneumatic pagoda connector for facilitating the installation of the pneumatic air pipe (28) and placing a sealing gasket, and the two sides of the cooling chamber (13) are provided with sealing rings to prevent gas from escaping to form a closed cooling chamber. The dilution device is used for diluting the carbon dioxide concentration in the gas to be detected and preventing mud from entering the sensor detection module, the dilution device comprises a dilution bin (17), the dilution bin (17) is integrally formed by 3D printing, pneumatic tower joints are respectively arranged on two sides of the dilution bin (17) to facilitate installation of pneumatic air pipes (28), and sealing gaskets are arranged at connecting positions of the pneumatic tower joints and the dilution bin (17); The carbon dioxide detection module comprises a carbon dioxide sensor (18), a circuit board (20) and a sensor air guide chamber (19), the carbon dioxide sensor (18) is arranged in the sensor air guide chamber (19), the sensor air guide chamber (19) is arranged on a rack (27), pneumatic tower joints are respectively arranged on two sides of the sensor air guide chamber (19) to facilitate installation of pneumatic air pipes (28), sealing gaskets are arranged at connecting positions of the pneumatic tower joints and the sensor air guide chamber (19), and the carbon dioxide sensor (18) is powered and data is transmitted through the circuit board (20).

2. A soil organic matter in-situ detection system for variable rate seeding according to claim 1, characterized in that, The control module comprises a main controller (21), a relay (23), a display (26), a power supply (24), a transformer (29), a motor controller and a man-machine interaction interface (25), the power supply (24) uses a 24V power supply, the transformer (29) is used for voltage reduction power supply, the main controller (21) is a Raspberry Pi 4B, the display (26) is used as a display terminal of the main controller (21), the man-machine interaction interface (25) is designed on the main controller (21) using Qt Creator 5 and is used.

3. A soil organic matter in-situ detection method for variable rate seeding, applied to the soil organic matter in-situ detection system for variable rate seeding, comprising the following steps: According to the research needs, the temperature of the high-temperature probe (1) is determined, and the high-temperature probe (1) is installed on the heating device fixing plate (5) of the linear motion mechanism; After reaching the detection area, the main controller (21) is started, the air pump (16) and the semiconductor refrigeration sheet (12) are turned on after the high-temperature probe (1) and the carbon dioxide sensor (18) are preheated, the high-temperature probe (1) is inserted into the soil and the air guide bin (2) is close to the soil surface through the linear motion mechanism, and the organic matter in the high-temperature soil is oxidized into carbon dioxide; Under the action of the air pump (16), the carbon dioxide gas is transmitted into the carbon dioxide sensor (18) through the air guide bin (2), the first-stage filtering device, the second-stage filtering and cooling device, the air pump (16) and the dilution device in sequence, so that the changing carbon dioxide concentration value is obtained; The carbon dioxide concentration value obtained by the carbon dioxide sensor (18) is transmitted to the main controller (21) through serial communication, the main controller (21) is calculated through a corresponding algorithm, finally, the soil organic matter detection result is displayed on the man-machine interaction interface (25), and is saved in an EXCEL table in real time for subsequent use.

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