A crop root high-density electrical impedance method in-situ measurement device and measurement method

Abstract

The present invention discloses an in-situ measurement device and method of crop root high-density electrical impedance method, the measurement device comprises a measurement disc, a receiver and a PC; the measurement disc is connected to the receiver, the receiver is connected to the PC, forming an integral measurement device; the measurement disc is used to fix multi-channel soil probes, and transmit the soil electrical impedance detected by each soil probe to the multi-wire socket on the measurement disc, and transmit it to the receiver through a multi-core cable; the receiver is used to quickly collect the soil electrical impedance value detected by each soil probe on the measurement disc, and transmit it to the PC through a transmission line. The present invention provides an important means for in-situ detection of crop root development by the non-destructive root electrical impedance method in the field, and is an important device for in-situ detection of the root electrical impedance method in the field, which is highly applicable, easy to operate, easy to carry, non-destructive and efficient.

Description

Technical Field

[0001] The invention belongs to the field of biological research technology equipment, and specifically relates to an in-situ measurement device for crop root system using high-density electrical impedance method. The invention also relates to an in-situ measurement method for crop root system using high-density electrical impedance method. Background Art

[0002] The root system of crops plays a core transmission role in the water balance and nutrient cycle of the soil-plant-atmosphere continuum. The underground distribution of crop roots is crucial to the development of crop plants and plays an important role in the response and adaptation mechanism of climate change and soil change. Therefore, studying the development of crop roots is an effective way to predict the yield of crop varieties and select excellent varieties. Traditional root research methods such as excavation, soil drilling, and profile methods are not only cumbersome, but also time-consuming and labor-intensive. In addition, there is a certain degree of human interference and destruction to the original living environment of the root system during the sampling process, which makes the accuracy of the research results questionable. In recent years, with the continuous development and progress of science and technology, the bioimpedance method has been widely promoted and used as a rapid and non-destructive root detection method. The bioimpedance method measures the electrical characteristics of the root system in the circuit under a certain frequency of external power supply, and there is a good correlation between the electrical characteristics and the root biomass and morphological indicators. The measurement of non-destructive root impedance is achieved by establishing a circuit loop of electrode-stem-root-soil or nutrient solution-electrode. Therefore, the core of the root impedance method research is to explore the influence of different components between the two electrodes on the root impedance and its extent, and to seek the best expression relationship between the root impedance parameter characteristics and the root system. With the clarification of the influence mechanism of the electrical characteristics of each component between the electrodes on the root impedance measurement, this influence mechanism can be used in turn to estimate the vitality of plant seeds, nutrient status, fruit damage, evaluate the salt and cold resistance of plants, diagnose drought, mechanical damage and disease detection, plant growth and health status and other scientific research.

[0003] At present, the field detection through the bioimpedance method mainly adopts the single repeated measurement method of the impedance meter. The so-called single repeated measurement means that the soil probe is inserted into the soil around the crop in batches for single measurement, and each measurement records a data. In this way, repeated probe measurement is performed in an area around the crop until a complete circular area measurement is formed around the root of the crop. Finally, the optimal expression relationship between the impedance parameter characteristics and the root system is used to analyze the root development status of the crop.

[0004] However, since the measurement position around the crop root is random at each time in the single repeated measurement method, and there is no unified measurement position regulation, there is a deviation when exploring the influence and degree of different components between the two electrodes on the root impedance. There are many uncertainties in the comparison of root development between different crops and the root comparison of different development stages of the same crop, and the measurement and analysis results are questionable. In addition, the single repeated measurement method of the impedance meter requires repeatedly inserting the soil probe into the soil multiple times, and recording a data for each measurement, which makes the whole operation more cumbersome, time-consuming and labor-intensive, and cannot realize the rapid acquisition and imaging of multiple soil probes. Summary of the invention

[0005] The purpose of the present invention is to provide an in-situ measurement device for crop root system high-density electrical impedance method, which solves the above problems.

[0006] The technical solution adopted by the present invention is an in-situ measurement device for crop root system high-density electrical impedance method, comprising: a measuring disc, a receiver and a PC;

[0007] The measuring disc is connected to the receiver, and the receiver is connected to the PC to form an integrated measuring device;

[0008] The measuring disc is used to fix the multi-channel soil probes, and transmit the soil electrical impedance detected by each soil probe to the multi-wire socket on the measuring disc, and then transmit it to the receiver through the multi-core cable;

[0009] The receiver is used to control the connection of each soil probe on the measuring disc, and measure the soil electrical impedance value detected by each soil probe on the disc, and then transmit it to the PC through the transmission line;

[0010] The PC is used to receive, analyze and display the geometric distribution of the electrical impedance between the measured circuit loops, and further analyze the development of the plant root system.

[0011] The measuring disc comprises a first semi-disc, a second semi-disc, a soil probe and a plant probe. The semi-disc is made of a PCB board. The first semi-disc and the second semi-disc are combined to form the measuring disc. A notch is provided at the center of each of the first semi-disc 1-5 and the second semi-disc 1-6. When the first semi-disc and the second semi-disc are combined, a penetration hole for the crop stem to pass through is formed in the middle. A plurality of probe through-holes for the soil probe to pass through are respectively arranged on the two semi-discs. A soldering pad is arranged around each probe through-hole. A spring terminal is welded on the soldering pad. A multi-wire socket is also welded on each semi-disc. The multi-wire socket is connected to the spring terminal through a connecting wire arranged on the semi-disc.

[0012] There are multiple soil probes, which are the same as the number of probe holes on the measuring disc. When the soil probe is inserted into the soil through the spring terminal, the spring on the spring terminal will squeeze the soil probe, so that the soil probe is firmly connected to the welding pad and the soil (or soil solution) is connected to the multi-wire socket on the measuring disc.

[0013] A plant probe is provided, and during detection, the plant probe is inserted into the stem of the plant, so that the plant probe is connected with the crop stem, the crop root system, the soil (or soil solution) and the soil probe;

[0014] The three connection structures provided by the measuring disc can connect the plant probe, the crop stem, the crop root system, the soil (or soil solution), the soil probe, the spring terminal, the PCB pad and the connection wire, and the multi-wire socket, thus forming a multi-channel complete circuit loop;

[0015] The receiver is composed of a multi-channel analog switch, an impedance analyzer, an A / D converter and a MUC control unit. The control end of the control unit is connected to the control end of the multi-channel analog switch, the output end of the multi-channel analog switch is connected to the input end of the impedance analyzer, the output end of the impedance analyzer is connected to the input end of the A / D converter, the input end of the A / D converter is connected to the signal input end of the control unit, and the signal output end of the control unit is connected to a PC.

[0016] During measurement, the signal input end of the receiver is connected to the plant probe and the multi-wire socket of the measuring disc respectively. The plant probe is connected to the positive voltage provided by the receiver (this positive voltage can be provided by the impedance analyzer inside the receiver). The control unit controls the multi-way analog switch and connects each soil probe on the measuring disc through the multi-wire socket on the measuring disc and the multi-core cable between the measuring disc and the receiver. When the control unit controls the multi-way analog switch, the impedance analyzer can connect and measure the electrical impedance value of the circuit loop between the plant probe and each soil probe in turn, and send the measured electrical impedance value to the PC after conversion by the A / D converter.

[0017] The signal input end of the PC is connected to the signal output end of the receiver. The PC is composed of a computer and an impedance spectrum analysis software. The PC 3 is used to receive and analyze, and display the measured impedance values ​​between the above-mentioned multiple circuit loops according to the geometric distribution form of the soil probes on the measuring disc. According to the optimal expression empirical relationship between the impedance parameter characteristics of the crop root system and the root system, the development results of the crop root system are further analyzed and judged.

[0018] A crop root high-density electrical impedance method in-situ measurement method, the specific working steps include:

[0019] Step 1, the first half disk and the second half disk are aligned to clamp the stem of the crop, and then the first disk and the second disk are horizontally placed on the ground;

[0020] Step 2, inserting a plurality of soil probes into the soil probe holes respectively, and piercing into the soil through the soil probe holes;

[0021] Step 3: Insert the plant probe into the stem of the crop to be tested. When the receiver is powered on, a positive voltage is applied to the plant probe.

[0022] Step 4, the receiver is powered on, the control unit of the receiver controls the multi-way analog switch, and the impedance analyzer is turned on in sequence and measures the electrical impedance between each soil probe and the plant probe on the measuring disk from near to far from the crop stem in the horizontal direction;

[0023] Step 5, the PC receives each impedance value measured by the impedance analyzer through the A / D converter and the control unit 2-4, and displays the distribution of the impedance on the PC according to the position distribution pattern of the soil probes on the measuring disc, and analyzes the development of the plant root system based on the best expression empirical relationship between the impedance parameter characteristics of the crop root system and the root system by the impedance spectrum analysis software.

[0024] The beneficial effects of the present invention are:

[0025] The present invention discloses an in-situ measurement device for crop root system using a high-density electrical impedance method, wherein the measurement disc comprises two semi-circular measurement discs, a first semi-circular disc and a second semi-circular disc. The design of a penetration hole formed in the middle by the first semi-circular disc and the second semi-circular disc being conducive to the penetration of crop root stems greatly facilitates the measurement of crop root system.

[0026] The first semi-disc and the second semi-disc are also provided with a plurality of probe holes for soil probes to pass through. A plurality of soil probes can be inserted into the soil through each probe hole on the measuring disc. Thus, when the measuring disc is fixed, each soil probe is in a fixed position around the crop root. This fundamentally eliminates the randomness of the measurement position selection due to the single repeated measurement method, thereby improving the accuracy of the in-situ measurement of the crop root system by the high-density electrical impedance method.

[0027] Through the three connecting structures set up by the measuring disc, multiple complete circuit loops can be formed between the plant probe and the multi-wire socket. Under the control of the control unit inside the receiver, these circuit loops are quickly connected to the impedance meter. The impedance meter will automatically measure the impedance values ​​of the crop roots and the surrounding soil, and send them to the PC for analysis and display, so as to quickly judge the development results of the crop roots.

[0028] In summary, the invention of a portable in-situ measurement device for crop root high-density electrical impedance method provides an important means for non-destructive in-situ detection of crop root development by the root electrical impedance method in the field. It is an important equipment for in-situ detection of root system electrical impedance method in the field, which is highly applicable, easy to operate, easy to carry, non-destructive and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a system composition block diagram of a portable crop root system high-density electrical impedance method in-situ measurement device.

[0030] Figure 2 It is a schematic diagram of a measuring disk 1 of a portable in-situ measuring device for a crop root system using a high-density electrical impedance method according to the present invention.

[0031] Figure 3 This is a measurement schematic diagram of a portable crop root high-density electrical impedance method in-situ measurement device of the present invention;

[0032] Figure 4 The present invention is a structural diagram of the connection between a measuring disc and a soil probe of a portable in-situ measuring device for crop root system high-density electrical impedance method.

[0033] In the figure, 1. Measuring disc, 1-1. Soil probe, 1-2. Probe perforation, 1-3. Penetration hole, 1-4. PCB board circuit pad, 1-5. First half disc, 1-6. Second half disc, 1-7. Multi-wire socket, 1-8. Multi-wire socket, 1-9. PCB board circuit connection, 1-10. PCB board circuit connection, 1-11. Spring terminal, 2. Receiver, 2-1. Multi-channel analog switch, 2-2. Impedance analyzer, 2-3. A / D converter, 2-4. Control unit, 3. PC, 4. Crop stem, 5. Crop root system, 6. Plant probe. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with the accompanying drawings and specific implementation methods. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection solution of the present invention.

[0035] The present invention provides a crop root high-density electrical impedance method in-situ measurement device, such as Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, it includes: a measuring disc 1, a receiver 2 and a PC 3; wherein the measuring disc 1 is connected to the receiver 2 at the back, and the receiver 2 is connected to the PC 3 at the back, so as to form a complete measuring device; the measuring disc 1 is used to fix the multi-channel soil probes 1-1, and transmit the soil electrical impedance detected by each soil probe to the multi-wire sockets 1-7 and 1-8 on the measuring disc 1, and transmit it to the receiver 2 through a multi-core cable; the receiver 2 is used to control the connection of each soil probe 1-1 on the measuring disc 1, and respectively measure the soil electrical impedance value detected by each soil probe 1-1, and then transmit it to the PC 3 through the transmission line. Specifically, the receiver controls the sequential connection of each soil probe on the measuring disc, and quickly measures the soil electrical impedance value detected by each soil probe, and transmits it to the PC through the transmission line; the PC 3 is used to receive, analyze and display the geometric distribution of the electrical impedance between the circuit loops obtained by measurement, and further analyze the development of the plant root system.

[0036] The measuring disc 1 comprises a first semi-disc 1-5, a second semi-disc 1-6, a soil probe 1-1 and a plant probe 6. The semi-discs are all made of PCB boards. The first semi-disc 1-5 and the second semi-disc 1-6 are matched to form the measuring disc 1. When the first semi-disc 1-5 and the second semi-disc 1-6 are matched, a penetration hole 1-3 is formed in the middle for the crop stem 4 to pass through. The two semi-discs are respectively provided with a plurality of probe penetration holes 1-2 for the soil probe to pass through. A welding pad 1-4 is arranged around each probe penetration hole 1-2. A spring terminal 1-11 is welded to the welding pad 1-4. Multi-wire sockets 1-7 and 1-8 are also welded to each semi-disc. The multi-wire sockets 1-7 and 1-8 are connected to the spring terminal 1-11 through connecting wires 1-9 and 1-10 provided on the semi-discs.

[0037] Furthermore, the size of the through hole 1-3 between the first half disk 1-5 and the second half disk 1-6 can be set according to the actual diameter of the crop stem, and the diameter of the soil probe through hole 1-2 is 2-4 mm. The number of soil probe through holes 1-2 on the measuring disk 1 will be set according to the size of the crop root system.

[0038] Further, by Figure 2 As shown, in order to facilitate the calculation and determination of the distribution of crop roots in the underground soil by the electrical impedance method, the multiple soil probes 1-1 on the measuring disc 1 are distributed on multiple virtually set distribution circles from near to far away from the crop stem 4, and these soil probes 1-1 are equally distributed on these circles. The number of soil probe distribution circles and the number of probes on each circle need to be determined according to the root distribution conditions of the crop type.

[0039] Furthermore, in order to prevent corrosion and improve durability, the soil probe 1-1 is made of stainless steel with a silver-plated surface and a diameter of 1-2 mm; the length of the soil probe 1-1 should be selected to be adapted to the depth of the crop root system 5 underground, and the length and thickness of the plant probe 6 should be selected so as not to harm the crop and to complete the in-situ measurement.

[0040] Furthermore, the measuring disc 1 of the present invention is made of a PCB board. In order to ensure that the measuring disc can measure in situ and avoid the connecting wires 1-9 and 1-10 on the measuring disc 1 from contacting and conducting with the ground soil during measurement, a three-layer PCB board can be made, and the connecting wires are placed in the second layer.

[0041] Furthermore, the measuring disc 1 disclosed in the present invention is composed of two semi-discs, a first semi-disc 1-5 and a second semi-disc 1-6, which is to adapt to the size requirements of the crop stem 4, but is not completely limited to the matching method of the two semi-discs. When the stem 4 of the plant is relatively thick, a multi-petal measuring disc can be used to enclose the plant stem to meet the needs of the plant stem passing through the penetration hole 1-3 of the measuring disc.

[0042] The soil probe 1-1 is provided with a plurality of probe holes 1-2, the number of which is the same as the number of the probe holes 1-2 provided on the measuring disc 1. When the soil probe 1-1 is inserted into the soil through the spring terminal 1-11, the spring on the spring terminal 1-11 will squeeze the soil probe 1-11, so that the soil probe 1-11 is firmly connected to the welding pad 1-4, and the soil (or soil solution) is connected to the multi-wire sockets 1-7 and 1-8 on the measuring disc 1;

[0043] Furthermore, the thickness and size of the spring terminal 1-11 should be compatible with the diameter of the soil probe 1-1 and the probe hole 1-2 on the measuring disc 1. It can be made of a DuPont locking female terminal, or modified from a phosphor bronze connector, or it can be developed and manufactured separately.

[0044] A plant probe 6 is provided. When testing, the plant probe 6 is inserted into the crop stem 4. In this way, the plant probe 6 is connected with the crop stem 4, the crop root system 5, the soil (or soil solution) and the soil probe 1-1.

[0045] The three connection structures provided on the measuring disc 1 can make the plant probe 6, the crop stem 4, the crop root 5, the soil (or soil solution), the soil probe 1-1, the spring terminal 1-11, the PCB pad 1-4 and the connecting wires 1-9 and 1-10, and the multi-wire socket connecting 1-7 and 1-8 form a multi-channel complete circuit loop;

[0046] The receiver 2 is composed of a multi-channel analog switch 2-1, an impedance analyzer 2-2, an A / D converter 2-3 and a MUC control unit 2-4, the control end of the control unit 2-4 is connected to the control end of the multi-channel analog switch 2-1, the output end of the multi-channel analog switch 2-1 is connected to the input end of the impedance analyzer 2-2, the output end of the impedance analyzer 2-2 is connected to the input end of the A / D converter 2-3, the input end of the A / D converter 2-3 is connected to the signal input end of the control unit 2-4, and the signal output end of the control unit 2-4 is connected to the PC 3;

[0047] Furthermore, the multi-way analog switch 2-1 in the receiver 2 can use 16 CD4051s and OC gates 74LS07 to form a 128-way analog multi-way switch, and select 100 of them as the multi-way analog switch 2-1 of the present invention (refer to the material "Design of 1024-way Analog Multi-way Switch" by Lu Xiqing and Wang Bingquan); the function of the multi-way analog switch 2-1 is to enable the impedance analyzer 2-2 to quickly and sequentially connect and measure the electrical impedance value of the circuit path between each soil probe 1-1 and the plant probe 6 on the disc under the control of the control unit 2-4.

[0048] Furthermore, after the analog switch 2 - 1 is turned on, the impedance analyzer 2 - 2 is turned on in sequence and measures the electrical impedance between each soil probe and the plant probe on the measuring disk 1 from near to far from the crop stem.

[0049] Furthermore, the impedance analyzer 2-2 can use a single or multiple frequency sine wave excitation electrical signal with a four-electrode configuration, and can adjust the vector voltage and vector current between the two electrodes, and then perform vector decomposition on the collected measured signal, thereby estimating various electrical parameters between the two electrodes and their frequency effects. At present, the impedance analyzer has been commercialized, and an impedance analyzer with an impedance value output interface can be selected and embedded in the receiver after modification.

[0050] Furthermore, the application of the A / D analog-to-digital converter 2-3 depends on the output data mode of the selected impedance analyzer 2-2. If the output of the impedance analyzer 2-2 has an RS232 or RS485 data output mode, the A / D analog-to-digital converter 2-3 can be cancelled. At this time, the output of the impedance analyzer 2-2 can communicate directly with the PC 3.

[0051] Furthermore, the control unit 2-4 can be developed by selecting a 51 single-chip microcomputer or other single-chip microcomputers. In addition to completing the communication with the PC, the control unit also needs to complete the control and acquisition of the multi-channel analog switch 2-1. The function of the control unit 2-4 is to control the analog switch 2-1 under the instruction sent by the human operating the PC (host computer) to the control unit 2-4 (slave computer), and sequentially connect the electrical impedance value loop between each soil probe and the plant probe, and send the electrical impedance value measured by the impedance analyzer to the host computer after A / D conversion.

[0052] During measurement, the signal input end of the receiver 2 is connected to the plant probe 6 and the multi-wire sockets 1-7 and 1-8 of the measuring disc 1 respectively, the plant probe 6 is connected to the positive voltage provided by the receiver 2, the control unit 2-4 controls the multi-way analog switch 2-1, and connects each soil probe 1-1 on the measuring disc 1 through the multi-wire sockets 1-7 and 1-8 on the measuring disc 1 and the multi-core cable between the measuring disc 1 and the receiver 2. When the control unit 2-4 controls the multi-way analog switch 2-1, the impedance analyzer 2-2 can connect and measure the electrical impedance value of the circuit loop between the plant probe 6 and each soil probe 1-1 in turn, and send the measured electrical impedance value to the PC 3 after conversion by the A / D converter 2-3.

[0053] Furthermore, the plant probe 6 is connected to the positive voltage provided by the impedance analyzer 2-2 inside the receiver 2, and the voltage value will be determined according to the soil impedance value and the measurement range of the impedance analyzer.

[0054] PC 3, the signal input end of PC 3 is connected to the signal output end of receiver 2, PC 3 is composed of a computer and electrical impedance spectrum analysis software, PC 3 is used to receive and analyze, and display the measured electrical impedance values ​​between the above-mentioned multiple circuit loops according to the geometric distribution form of the soil probes 1-1 on the measuring disc 1, and further analyze and judge the development results of the crop root system according to the optimal expression empirical relationship between the electrical impedance parameter characteristics of the crop root system and the root system.

[0055] Furthermore, the analysis and display software used in the PC can use the commercial software Zview and the free software LEVM program (http: / / www.jrossmacdonald.com / levminfo.html) that use the nonlinear least squares fitting principle adopted in the electrical impedance spectrum equivalent circuit parameter fitting to solve the parameters of the electronic components of the equivalent circuit, and then analyze the development status of the soil root system based on the optimal expression relationship between the root system electrical impedance parameter characteristics and the root system.

[0056] A crop root high-density electrical impedance method in-situ measurement method, characterized in that the specific working steps of the device include:

[0057] Step 1, the first half disk 1-5 and the second half disk 1-6 are matched to clamp the stem of the crop to be measured on the ground, so that the stem 4 of the crop on the ground passes through the through hole 1-3 on the measuring disk 1, and then the first half disk 1-5 and the second half disk 1-6 are horizontally placed on the ground;

[0058] Step 2, inserting a plurality of soil probes 1-1 into the soil probe holes 1-2 respectively, and penetrating into the soil through the soil probe holes 1-2;

[0059] Step 3, insert the plant probe 6 into the stem 4 of the crop to be tested, and when the receiver 2 is powered on, a positive voltage is applied to the plant probe 6;

[0060] Step 4, the receiver 2 is powered on, the control unit 2-4 of the receiver 2 controls the multi-way analog switch 2-1, and the impedance analyzer 2-2 is turned on in sequence and detects the electrical impedance between each soil probe 1-1 and the plant probe 6 on the measuring disk 1 from near to far in the horizontal direction from the crop stem 4;

[0061] Step 5, the PC 3 receives each impedance value measured by the impedance analyzer 2-2 through the A / D converter and the control unit 2-4, and displays the distribution of the impedance on the PC 3 according to the position distribution pattern of the soil probe 1-1 on the measuring disc 1, and analyzes the development of the plant root system based on the impedance spectrum analysis software according to the optimal expression empirical relationship between the crop root impedance parameter characteristics and the root system.

[0062] The embodiments described above are only preferred specific implementation methods of the present invention, and the protection scope of the present invention is not limited thereto. Any simple changes or equivalent replacements of the technical solutions that can be obviously obtained by any technician familiar with the field within the technical scope disclosed in the present invention belong to the protection scope of the present invention.

Claims

1. An in-situ measurement device for crop root system high-density electrical impedance method, It is characterized in that include: Measuring disc, receiver and PC; The measuring disc is connected to the receiver, and the receiver is connected to the PC to form an integrated measuring device; The measuring disc is used to fix the multi-channel soil probes, and transmit the soil electrical impedance detected by each soil probe to the multi-wire socket on the measuring disc, and then transmit it to the receiver through the multi-core cable; The receiver is used to control the connection and quickly collect the soil electrical impedance value detected by each soil probe on the measuring disc, and transmit it to the PC through the transmission line; The PC is used to receive, analyze and display the geometric distribution of the electrical impedance between the circuit loops measured, and further analyze the development of the plant root system; The measuring disc comprises a first semi-disc, a second semi-disc, a soil probe and a plant probe, each of the semi-discs is made of a PCB board, and the first semi-disc and the second semi-disc are matched to form the measuring disc; a notch is provided at the center of the first semi-disc and the second semi-disc, so that when the first semi-disc and the second semi-disc are matched, a penetration hole for the crop stem to pass through is formed in the middle, and a plurality of probe through-holes for the soil probe to pass through are respectively arranged on the two semi-discs, and soldering pads are arranged around each probe through-hole, and spring terminals are welded on the soldering pads, and a multi-wire socket is respectively welded on each semi-disc, and the multi-wire socket is connected to the spring terminals through connecting wires arranged on the semi-discs.

2. A crop root high-density electrical impedance method in-situ measurement device as claimed in claim 1, It is characterized in that There are multiple soil probes, which are the same number and correspond one to one with the probe holes set on the measuring disc. When the soil probe is inserted into the soil through the probe holes, the spring sheet on the spring terminal will squeeze the soil probe, so that the soil probe is firmly connected to the welding pad and the soil is connected to the multi-wire socket on the measuring disc.

3. The crop root high-density electrical impedance method in-situ measurement device according to claim 1, It is characterized in that The plant probe is set as one, and when detecting, the plant probe is inserted into the stem of the plant, so that the plant probe is connected with the crop stem, crop root system, soil and soil probe; then the plant probe, crop stem, crop root system, soil, soil probe, spring terminal, PCB board pad and connecting wire and multi-wire socket are connected to form a multi-channel complete circuit loop.

4. The crop root high-density electrical impedance method in-situ measurement device according to claim 1, It is characterized in that The receiver is composed of a multi-channel analog switch, an impedance analyzer, an A / D converter and a MUC control unit, wherein the control end of the control unit is connected to the control end of the multi-channel analog switch, the output end of the multi-channel analog switch is connected to the input end of the impedance analyzer, the output end of the impedance analyzer is connected to the input end of the A / D converter, the input end of the A / D converter is connected to the signal input end of the control unit, and the signal output end of the control unit is connected to a PC; When measuring, the in-situ measurement device of crop root high-density electrical impedance method connects the signal input end of the receiver to the plant probe and the multi-wire socket of the measuring disc respectively, the plant probe is connected to the positive voltage provided by the receiver, the control unit controls the multi-way analog switch, and connects each soil probe on the measuring disc through the multi-wire socket on the measuring disc respectively. When the control unit controls the multi-way analog switch, the impedance analyzer can connect and measure the electrical impedance value of the circuit loop between the plant probe and each soil probe in turn, and sends the measured electrical impedance value to the PC after conversion by the A / D converter.

5. The crop root high-density electrical impedance method in-situ measurement device as claimed in claim 4, It is characterized in that The signal input end of the PC is connected to the signal output end of the receiver. The PC includes a computer and electrical impedance spectrum analysis software in the computer. The PC is used to receive and analyze, and display the measured electrical impedance values ​​between the multiple circuit loops according to the geometric distribution form of the soil probes on the measuring disc. According to the optimal expression empirical relationship between the electrical impedance parameter characteristics of the crop root system and the root system, the development results of the crop root system are further analyzed and judged.

6. A method for in-situ measurement of crop root system using high density electrical impedance method. It is characterized in that The device of claim 5 is used for measurement, and the steps of the measurement method include: Step 1, the first half disk and the second half disk are aligned to clamp the stem of the crop, and then the first disk and the second disk are horizontally placed on the ground; Step 2, inserting a plurality of soil probes into the soil probe holes respectively, and piercing into the soil through the soil probe holes; Step 3: Insert the plant probe into the stem of the crop to be tested. When the receiver is powered on, a positive voltage is applied to the plant probe. Step 4, the receiver is powered on, the control unit of the receiver controls the multi-way analog switch, and the impedance analyzer is turned on in sequence and measures the electrical impedance between each soil probe and the plant probe on the measuring disk from near to far from the crop stem in the horizontal direction; Step 5. The PC receives each impedance value measured by the impedance analyzer through the A / D converter and the control unit, and displays the distribution of the impedance on the PC according to the position distribution pattern of the soil probes on the measuring disc. Based on the optimal expression empirical relationship between the impedance parameter characteristics of the crop root system and the root system, the impedance spectrum analysis software analyzes the development of the plant root system.

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