Leaf area index measuring device and method

Abstract

The invention discloses a leaf area index measuring device and method, the measuring device comprises a plurality of measuring rings with different radiuses and a data processing system, the adjacent measuring rings are connected through a connecting section, and each measuring ring is provided with a strike sensor for measuring rainfall intensity, rainwater strike frequency and rainwater strike time; and the data processing system is used for receiving and processing data measured by the strike sensor to obtain the leaf area index of the plant. The leaf area index of the plant can be conveniently calculated in most scenes, labor is saved, and efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural equipment, and particularly to a leaf area index measurement device and method. Background Art

[0002] The leaf area index (LAI) is an important indicator reflecting the growth status of plant populations, and its size is directly closely related to the final yield. However, the existing methods for calculating the leaf area index use a ruler to measure the leaf length (Lij) and the maximum leaf width (Bij) of each leaf and substitute them into an empirical formula for calculation. The calculation process is complex, and the existing fertilization amount calculation technology is relatively backward, without making full use of modern technologies such as sensors, the Internet of Things, and artificial intelligence for real-time monitoring and data analysis. Secondly, the accuracy of calculating the leaf area index depends to a large extent on the quality and accuracy of the data used, and the existing data sources often have problems of inaccuracy, incompleteness, or inconsistency. Summary of the Invention

[0003] Object of the Invention: Aiming at the disadvantages of low accuracy and efficiency in the existing calculation of the leaf area index, the present invention provides a leaf area index measurement device and method.

[0004] Technical Solution: To solve the above problems, the present invention adopts a leaf area index measurement device, including a plurality of measurement rings with different radii and a data processing system. Adjacent measurement rings are connected by a connecting section, and each measurement ring is provided with a strike sensor for measuring rainfall intensity, rain strike frequency, and rain strike time; the data processing system is used to receive and process the data measured by the strike sensor to obtain the leaf area index of the plant.

[0005] Further, the surfaces of the measurement ring and the connecting section are covered with an inflatable film. One side of the inflatable film is connected to an air pump, and a rain sensor is also provided on the inflatable film. The rain sensor is connected to the air pump through a signal line. When the rain sensor detects moisture, the air pump inflates the inflatable film and then deflates it after inflation is completed.

[0006] Further, the measurement ring is a splicing structure, and the measurement ring includes two semi-circular rings. One end of the semi-circular ring is provided with a connecting member, and the other end is provided with an installation groove for inserting the connecting member.

[0007] Further, the connecting section is a telescopic structure, including a sleeve rod and a telescopic rod, and a manual adjustment knob is also provided on the connecting section for adjusting the length of the telescopic rod extending out of the sleeve rod.

[0008] Further, the data processing system includes a display and an information processor, and the information processor is connected to the strike sensor and the display through a data transmission line.

[0009] Further, a plurality of impact sensors are provided on each measurement ring, and the impact sensors are equidistantly distributed in a circle.

[0010] Further, the measurement ring is made of polyethylene or polypropylene material.

[0011] Further, the inflatable film is made of PVDF film material.

[0012] Further, the connecting section is made of rubber or plastic material.

[0013] The present invention also provides a measurement method for the above leaf area index measurement device, including the following steps:

[0014] Step 1: Select a standard plant with a leaf area index of 1, place the main trunk of the standard plant inside the innermost measurement ring, and ensure that there is no canopy obstruction above the outermost measurement ring; measure the rain impact time of the outermost measurement ring and one of the inner measurement rings under different rainfall intensities P1’, P2’, P3’…P x ’, and the data processing system calculates the rain impact time difference T1’, T2’, T3’…T x ’ between the inner measurement ring and the outermost measurement ring;

[0015] Step 2: Install the measurement device on the plant to be measured, place the main trunk of the plant to be measured inside the innermost measurement ring, and ensure that there is no canopy obstruction above the outermost measurement ring; divide each area of the plant corresponding to each measurement ring into a sparse area and a dense area based on whether the measurement ring is visible from a top view;

[0016] Step 3: Measure and calculate the leaf area index; for the sparse area, the leaf area index S is calculated as follows:

[0017]

[0018] N 外环 is the rain impact frequency on the outermost measurement ring, and N 内环 is the rain impact frequency on the measurement ring corresponding to this area;

[0019] For the dense area, according to the current rainfall intensity P x measured by the impact sensor, find the corresponding T x = P x ’ in Step 1, and the leaf area index S is calculated as follows: x

[0020]

[0021] ​Beneficial effects: Compared with the prior art, the present invention provides a novel device and method for calculating the leaf area index, which can conveniently calculate the leaf area index of plants in most scenarios, save labor, and improve efficiency. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the overall structure of the measuring device of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of the inflated film of the measuring device of the present invention in a bulged state;

[0024] Figure 3 It is a schematic diagram of the splicing structure of the measuring ring of the present invention;

[0025] Figure 4 It is a schematic diagram of the telescopic structure of the connecting section of the present invention;

[0026] Figure 5 It is a schematic diagram of the installation structure of the rain sensor of the present invention;

[0027] Figure 6 It is a schematic diagram of the air pump connection structure of the present invention;

[0028] Figure 7 It is a schematic diagram of the data processing system structure of the present invention. Detailed Embodiments

[0029] As Figures 1 to 7 shown, a leaf area index measuring device in this embodiment includes a plurality of measuring rings 3 with different radii and a data processing system. Adjacent measuring rings 3 are connected by a connecting section 4. The measuring device in this embodiment is provided with three measuring rings 3 with different radii. The measuring ring 3 is a splicing structure, including two semi-circular rings. One end of the semi-circular ring is provided with a connecting member 14, and the other end is provided with an installation groove for inserting the connecting member 14. The connecting member 14 of one semi-circular ring is inserted into the installation groove of the other semi-circular ring to realize the splicing of the measuring ring 3.

[0030] Each measuring ring 3 is provided with a percussion sensor 7 for measuring rainfall intensity, rain strike frequency, and rain strike time. In this embodiment, each measuring ring 3 is provided with four percussion sensors 7, and the percussion sensors 7 are evenly distributed in a circle. A bracket 2 is also provided at the bottom of the measuring ring 3, and bolt holes are reserved on the bracket 2 to facilitate fixing the bracket 2 to the measuring area through bolts 1.

[0031] The connecting section 4 is a telescopic structure, including a sleeve rod and a telescopic rod. A manual adjustment knob 5 is also provided on the connecting section 4 for adjusting the length of the telescopic rod extending out of the sleeve rod.

[0032] The surfaces of the measuring ring 3 and the connecting section 4 are covered with an inflatable film 12. One side of the inflatable film 12 is connected to an air pump 13, and a rain sensor 11 is also provided on the inflatable film 12. The rain sensor 11 is connected to the air pump 13 through a signal line 6. When the rain sensor 11 detects rainfall, the air pump 13 will be started to inflate the inflatable film 12, causing the inflatable film 12 to bulge quickly and bounce off debris such as fallen leaves on the inflatable film 12 to avoid the debris affecting subsequent measurement results. After inflation is completed, the air pump 13 quickly extracts the gas again to make the inflatable film 12 return to its original state to avoid affecting the measurement of the impact sensor 7.

[0033] The data processing system includes a display 9 and an information processor 10. The information processor 10 is connected to the impact sensor 7 and the display 9 through a data transmission line 8. After receiving the data from the impact sensor 7, the information processor 10 processes it and transmits the received and processed data to the display 9 for display.

[0034] To power the device, a solar panel can be installed on the top or side of the measuring ring 3 to ensure that the solar panel can receive the maximum amount of sunlight. Connect the output line of the solar panel to the circuit inside the device and connect the output end of the solar panel to the power interface inside the device through a wire.

[0035] The material selection of the measuring ring 3 of the present invention is crucial. It needs to have corrosion resistance, stability and environmental adaptability. Therefore, high-density polyethylene (HDPE) or polypropylene (PP) is selected. These materials are widely used in agricultural applications due to their chemical resistance, mechanical stability and durability. They can withstand different climate conditions, from hot summer days to cold winter days, and also have good resistance to various chemicals in fertilizers and soil. The connecting section 4 is made of a soft and durable material, such as rubber or plastic, to ensure the flexibility and reliability of the connection. The inflatable film 12 needs to be a soft and elastic material so that it can smoothly bounce off debris after inflation. In this embodiment, the inflatable film 12 made of PVDF film material is selected.

[0036] This embodiment also provides a measuring method for the above leaf area index measuring device, including the following steps:

[0037] Step 1: Select a standard plant with a leaf area index of 1 (find the closest within the allowable error range of 2%), place the main trunk of the standard plant inside the innermost measuring ring 3, and there is no canopy obstruction above the outermost measuring ring 3; measure the rain strike times of the outermost measuring ring 3 and one of the inner measuring rings 3 under different rainfall intensities P1’, P2’, P3’…P x ’, and the data processing system calculates the rain strike time differences T1’, T2’, T3’…T x ’ between this inner measuring ring 3 and the outermost measuring ring 3.

[0038] Step 2: Install a measuring device on the plant to be measured, so that the main trunk of the plant to be measured is located inside the innermost measuring ring 3, and there is no canopy obstruction above the outermost measuring ring 3; taking whether the measuring ring is visible in a top-down view as the standard, divide each area of the plant corresponding to above each measuring ring 3 into a sparse area and a dense area.

[0039] Step 3: Measure and calculate the leaf area index; for the sparse area, the leaf area index S is calculated as follows:

[0040]

[0041] In the formula, A 叶片 is the total leaf area above the measuring ring, and the land area A 土 is equivalent to the area A of the measuring ring 环 , F 植 is the number of times the leaves are hit by raindrops, and F 外环 is the number of times the outermost measuring ring without leaf obstruction is hit by raindrops. Also, since both the plant and the outermost measuring ring come into contact with rainfall for the first time, the rainfall durations of the two are the same, that is:

[0042]

[0043] In the formula, N 植 is the rain strike frequency experienced by the plant leaves, and N 外环 is the rain strike frequency on the outermost measuring ring. N 植 is equivalent to the difference between the rain strike frequency of the outermost measuring ring and the rain strike frequency of the inner measuring ring, so the formula is transformed:

[0044]

[0045] N 内环 is the rain strike frequency on the measuring ring corresponding to this area.

[0046] For the dense area, the interception effect of the leaves needs to be considered, and there is a strike time difference between the inner measuring ring and the outer measuring ring. Due to the lush leaves, there are many leaf areas that are difficult to measure in the overlap of the leaves. So let A 叶片 = A 叶片’ + A 叶片” . A 叶片’ is the sum of the areas of the topmost leaves in each direction. Since it is assumed that the leaves are lush, so A 叶片’ = A 环 . A 叶片” is the sum of the areas of all the leaves below the leaves. Then:

[0047]

[0048] From the set (T’, P’) of the time difference T affected by plant interception and rainfall intensity P when the leaf area index is 1 (the leaf area above the ring is close to the area of the ring) found in the previous experiment, find the rainfall P for this rainfall x = P x ’ and the corresponding time difference T x ’. So A 叶片’ = A 环 ’s interception time is T’, then A 叶片” = T - T x ’. Since the rainfall intensity is inversely proportional to the time difference, so:

[0049]

[0050] The data processing and analysis idea of the present invention is as follows: Generally speaking, the greater the impact degree on the measuring ring 3 and the higher the impact frequency, the greater the amount of rain under the plant leaves. Therefore, the plant growth condition may be poor, or the number of leaves may be small, the leaf area index may be small, and the plant may require more water or fertilizer for growth and need additional fertilization; on the contrary, the smaller the impact degree and the fewer the impact times, the smaller the amount of rain under the plant leaves. Therefore, the plant growth condition may be better, the number of leaves may be large, the leaf area index may be large, and the water or fertilizer supply for plant growth is sufficient, and there is no need to apply too much additional fertilizer. Analysis of plant growth condition: According to the size of the impact time difference, the information processor 10 analyzes the growth state of the plant. If the impact time difference value is large, it indicates that the leaf growth and development condition at a certain place of the plant is good and the leaf area index is large; if the impact time difference value is small, it indicates that the leaves at a certain place of the plant are sparse or withered and the leaf area index is small. Finally, based on the leaf area index of different plant canopies measured by the device of the present invention, it can provide a basis for subsequent irrigation, fertilization and pest monitoring.

Claims

1. A leaf area index measuring device, characterized in that, It includes a number of measurement rings (3) with different radii and a data processing system. Adjacent measurement rings (3) are connected by connecting sections (4). A strike sensor (7) for measuring rainfall intensity, raindrop strike frequency, and raindrop strike time is provided on each measurement ring (3); the data processing system is used to receive and process the data measured by the strike sensor (7) to obtain the leaf area index of the plant.

2. The leaf area index measuring device according to claim 1, characterized in that, The surfaces of the measurement ring (3) and the connecting section (4) are covered with an inflatable film (12). An air pump (13) is connected to one side of the inflatable film (12). A rain sensor (11) is also provided on the inflatable film (12). The rain sensor (11) is connected to the air pump (13) through a signal line (6). When the rain sensor (11) detects moisture, the air pump (13) inflates the inflatable film (12) and then deflates it after inflation is completed.

3. The leaf area index measuring device according to claim 1, wherein The measurement ring (3) is a splicing structure. The measurement ring (3) includes two semi-circular rings. A connecting member (14) is provided at one end of the semi-circular ring, and a mounting groove for inserting the connecting member (14) is provided at the other end.

4. The leaf area index measuring device according to claim 1, wherein The connecting section (4) is a telescopic structure, including a sleeve rod and a telescopic rod. A manual adjustment knob (5) is also provided on the connecting section (4) for adjusting the length of the telescopic rod extending out of the sleeve rod.

5. The leaf area index measuring device according to claim 1, characterized in that, The data processing system includes a display (9) and an information processor (10). The information processor (10) is connected to the strike sensor (7) and the display (9) through a data transmission line (8).

6. The leaf area index measuring device according to claim 1, characterized in that A plurality of strike sensors (7) are provided on each measurement ring (3), and the strike sensors (7) are evenly distributed at equal distances in a circumferential manner.

7. The leaf area index measuring device according to claim 1, characterized in that, The measurement ring (3) is made of polyethylene or polypropylene material.

8. The leaf area index measuring device according to claim 1, characterized in that, The inflatable film (12) is made of PVDF film material.

9. The leaf area index measuring device according to claim 1, wherein, The connecting section (4) is made of rubber or plastic material.

10. A measurement method of the leaf area index measurement device according to any one of claims 1-9, characterized in that, It includes the following steps: Step 1: Select a standard plant with a leaf area index of 1, place the main trunk of the standard plant inside the innermost measurement ring (3), and ensure that there is no canopy obstruction above the outermost measurement ring (3). Measure the rain hitting time of the outermost measurement ring (3) and one of the inner measurement rings (3) under different rainfall intensities P1’, P2’, P3’…P x ’. The data processing system calculates the rain hitting time differences T1’, T2’, T3’…T x ’ between the inner measurement ring (3) and the outermost measurement ring (3); Step 2: Install the measuring device on the plant to be measured, place the main trunk of the plant to be measured inside the innermost measurement ring (3), and ensure that there is no canopy obstruction above the outermost measurement ring (3); taking whether the measurement ring is visible in a top-down view as the standard, divide each area of the plant corresponding to the upper part of each measurement ring (3) into a sparse area and a dense area. Step 3: Measure and calculate the leaf area index; for the sparse area, the leaf area index S is calculated as follows: N 外环 is the rain hitting frequency on the outermost measurement ring (3), N 内环 is the rain hitting frequency on the measurement ring corresponding to this area; For the dense area, according to the current rainfall intensity P measured by the impact sensor (7) x , find the T x =P x ' corresponding to P x ' at this time, and the leaf area index S is calculated as follows:

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