A layered sampling device for tracking and detecting nitrate data in pastoral soils and method thereof

Abstract

The application discloses a layered sampling device for tracking and detecting nitrate data of soil in a pastoral area and a method thereof. The sampling device comprises a sampling cylinder assembly, at least two sampling cylinders, an axial pushing assembly and a brittle fracture piece. The at least two sampling cylinders are coaxially sleeved and connected in a stacked mode. The axial pushing assembly is connected to the upper end of the outermost sampling cylinder to apply axial pushing force to the sampling cylinder assembly when collecting soil samples. The brittle fracture piece has a plurality of brittle fracture pieces. Each of the brittle fracture pieces is arranged on the upper end face of the outer sampling cylinder. One end of the brittle fracture piece abuts against the upper end face of the inner sampling cylinder of the sampling cylinder. When the axial force from the abutting sampling cylinder is greater than the threshold value of the brittle fracture piece, the brittle fracture piece is broken, so that the sampling cylinder where the brittle fracture piece is located can be inserted into the soil under the axial force. The device and the method can realize clean and convenient sampling of soil in the pastoral area.

Description

Technical Field

[0001] This invention relates to soil testing devices for pastoral areas, and in particular to a stratified sampling device and method for tracking and detecting nitrate data in pastoral soils. Background Technology

[0002] The grassland nitrogen cycle is crucial for maintaining ecosystem health and stability. Soil nitrate, the most biologically active form of nitrogen, is highly susceptible to grazing activity and is a key factor reflecting the dynamic changes in the nitrogen cycle. When studying the transfer and transformation processes and budget changes of nitrate in pastoral soils, due to differences in grazing use and the inherent characteristics of grassland soil nitrogen cycling, it is necessary to collect soil samples across regions and at multiple levels to obtain relevant data, establish a tracking model based on stable nitrate isotopes, and quantitatively analyze the transfer and transformation processes of nitrate within the soil and between nitrate and plants and the atmosphere. By analyzing the relationships between nitrate budget changes and relevant soil physicochemical parameters and grassland use, this study elucidates the impact of grazing on grassland nitrogen cycling, providing theoretical guidance for grazing use from the perspective of grassland nitrogen nutrient management.

[0003] Soil nitrate samples need to be collected at multiple levels. That is, at the same sampling point, soil samples need to be collected at different depths such as 0-10cm, 10-20cm, and 20-30cm for subsequent data analysis in the laboratory.

[0004] Traditional soil sampling devices mostly use integrated sampling tubes, which are easy to operate but have significant drawbacks. Especially in soil environments with low clay and moisture content, such as grasslands in northern my country, the insertion of the sampling tube easily carries surface soil and attached organic matter into deeper layers, leading to cross-contamination between samples from different soil layers. This severely affects the accuracy and reliability of nitrate content detection. Therefore, there is an urgent need for a specialized device and method that can achieve clean, stratified sampling to ensure the scientific rigor and accuracy of soil nitrate and isotope research. Summary of the Invention

[0005] The purpose of this invention is to provide a stratified sampling device and method for tracking and detecting nitrate data in pastoral soils, in order to solve the problem that existing soil sampling devices are prone to contamination when collecting grassland soil samples.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A stratified sampling device for tracking and detecting nitrate data in pastoral soils includes:

[0008] A collection tube assembly includes at least two collection tubes, wherein the at least two collection tubes are connected coaxially in a stacked manner;

[0009] A pressure - applying component, connected to the upper end of the outermost collection cylinder, to apply an axial thrust to the collection cylinder component when collecting soil samples;

[0010] Brittle parts, there are multiple brittle parts, and at least one brittle part is arranged on the upper end surface of each outer - side collection cylinder. One end of the brittle part abuts against the upper end surface of the collection cylinder inside the collection cylinder where it is located. When the axial force received by the brittle part from the abutted collection cylinder is greater than its own threshold value, the brittle part cracks, so that the collection cylinder where the brittle part is located can be inserted downward into the soil under the axial force.

[0011] Preferably, according to the distribution positions on the collection cylinder, the cracking threshold values of the brittle parts gradually increase from the inside to the outside.

[0012] Preferably, the brittle part is in an n - shape, including a plug - in part, a brittle part, and an abutting part. The brittle part extends horizontally. One end of the brittle part where it is located is connected to the plug - in part, and the plug - in part can be detachably inserted into the collection cylinder where it is located. The other end of the brittle part is connected to the abutting part.

[0013] Preferably, a guiding groove is opened on the brittle part.

[0014] Preferably, the plug - in part is inserted into the collection cylinder at a certain inclination angle with the axis of the collection cylinder.

[0015] Preferably, a plurality of plug - in grooves are opened on the collection cylinder, and the plurality of plug - in grooves are distributed in a staggered manner on the upper end surface of the collection cylinder.

[0016] Preferably, the collection cylinder includes two half - cylinders, and after the two half - cylinders are assembled, they are connected by bolts.

[0017] Preferably, a travel groove extending along the axis is opened on the outer surface of the inner - side collection cylinder, and a slider slidably arranged in the travel groove is arranged on the inner side surface of the outer - side collection cylinder.

[0018] Preferably, the pressure - applying component includes a telescopic cylinder A connected to the upper end surface of the outermost collection cylinder. The upper end of the telescopic cylinder A is connected to a splicing plate. The two ends of the splicing plate are symmetrically connected to pedals. The pedals are connected to the splicing plate to form a "ji" - shaped structure. A telescopic cylinder B is also arranged on the ( ) pressing plate. A hook is arranged at the lower end of the telescopic cylinder B. A hanging ring capable of being hooked with the hook is arranged on the end surface of the innermost collection cylinder.

[0019] A layered sampling method for tracking and detecting soil nitrate data in pastoral areas, including:

[0020] S1 Sampling Units: Several units with different grazing utilization methods (such as enclosed pastures, hayfields, rotational grazing pastures, collective pastures, etc.) and utilization intensities (no grazing, light grazing, moderate grazing, heavy grazing, etc.) are identified in the study area.

[0021] S2 Sampling tool selection: Select one of the stratified sampling devices for tracking and detecting nitrate data in pastoral soils from this scheme to collect soil samples;

[0022] S3 Determine the collection time: The collection time is during the greening period, the peak grass growth period, or before and after fertilization of some grasslands, in order to compare the dynamics of nitrate under different plant growth and human interference.

[0023] S4 Determine the collection location: Randomly select a representative location in the divided unit that is flat, has uniform vegetation growth, and avoids roads, fences, residential areas, and livestock drinking points;

[0024] S5 determines the sampling depth: collect soil samples at multiple depths of 0~10cm, 10~10cm, and 20~30cm;

[0025] S6 Starts Collection: The telescopic cylinder A in the pressure application assembly extends, thereby driving the collection tube assembly to insert into the soil. As the soil surface contacts the innermost end of the collection tube, the collection tube has no more space to insert further. At this time, the telescopic cylinder A continues to extend, and the axial force on the collection tube assembly continues to increase. When the axial force rises to a threshold, the brittle component of the innermost ring breaks. The collection tube outside the innermost collection tube loses the connection constraint between it and the innermost collection tube, and can then continue to be inserted into the soil. At this time, the soil sample of the uppermost layer 0~10cm depth is collected. The second collection tube is inserted to collect the second layer of soil samples at a depth of 10~20cm. When the second collection tube is inserted to the bottom, as the telescopic cylinder A continues to apply pressure, the brittle component of the second ring also breaks. This cycle repeats until the soil samples of all depths are collected.

[0026] S7 Extracting Soil Samples: The telescopic cylinder B in the pressure application assembly extends downward, then the hook on the telescopic cylinder B connects with the hanging ring, and then the telescopic cylinder B retracts, thereby applying an axial upward pulling force to the innermost collection tube, thus extracting the collection tube assembly with the soil sample from the soil. It should be noted that when the telescopic cylinder B retracts, the telescopic cylinder A also retracts synchronously to ensure the smooth extraction of the collection tube assembly.

[0027] S8 Packaging Numbering: Remove the collected soil samples from the collection tube assembly and label them according to the time, location, and depth of the soil samples collected.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] The sampling tube assembly in this solution consists of multiple sampling tubes. When used in conjunction with the brittle fracture component, it enables each sampling tube to be inserted in stages from the inside out during the soil sampling process. This sampling method can effectively avoid the huge errors caused by the existing integral sampling tubes bringing the surface sample directly to the bottom of the soil, thereby effectively reducing the data deviation caused by sample contamination.

[0030] In this design, the brittle fracture threshold of the brittle components installed on the sampling tube increases from the inside to the outside of the components, so as to effectively ensure that the insertion sequence of the sampling tubes in the sampling tube assembly is controllable when the sampling tube assembly is inserted into the soil.

[0031] The insertion part of the brittle component adopts an insertion method with a certain angle to the axis of the collection cylinder to avoid the axial force of the collection cylinder on the brittle component causing the brittle component to fall out of the collection cylinder. In this way, the stability of the insertion connection between the brittle component and the collection cylinder is guaranteed.

[0032] Multiple insertion slots are provided, which means that the threshold value of the insertion slot can be easily and quickly adjusted by adjusting the brittle component installed on each layer of the collection tube.

[0033] The collection tube consists of two halves to facilitate subsequent disassembly and extraction of soil samples.

[0034] The pressure application component adopts a structure of telescopic cylinder A and pedal. When collecting samples, the collection tube is placed on the soil surface. Then, after the sampling personnel step on the pedal with both feet, the telescopic cylinder A is extended. At this time, the collection tube component can be inserted into the soil with a stable force, reducing the instability of pressure caused by manual application. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure in the initial state of the present invention;

[0036] Figure 2 This is an exploded view of the present invention;

[0037] Figure 3 for Figure 1 A sectional view;

[0038] Figure 4 This is a diagram showing the state of the soil samples collected for this project;

[0039] Figure 5 This is an exploded view of the data collection tube assembly;

[0040] Figure 6 This is a schematic diagram of the structure of a brittle fracture component;

[0041] Figure 7 This is a magnified view of a section marked I;

[0042] Figure 8 This is a magnified view of a section marked II;

[0043] Figure 9 This is a magnified view of a section marked III.

[0044] Reference numerals: 1. Sampling cylinder assembly; 11. Sampling cylinder; 111. Half cylinder; 112. Insertion slot; 113. Stroke slot; 114. Slider; 2. Pressure application assembly; 21. Telescopic cylinder A; 22. Pressure plate; 23. Pedal; 24. Telescopic cylinder B; 25. Hook; 26. Hanging ring; 3. Fractured part; 31. Insertion part; 32. Fractured part; 33. Abutment part; 34. Guide slot. Detailed Implementation

[0045] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0048] like Figure 1 The stratified sampling device for tracking and detecting nitrate data in pastoral soils shown includes a collection tube assembly 1, a pressure application assembly 2, and a brittle component 3.

[0049] like Figure 2 , Figure 5 As shown, the sampling tube assembly 1 is formed by the sliding fit of at least two sampling tubes 11. It should be noted that when the number of sampling tubes 11 is greater than two, multiple sampling tubes 11 are stacked together to form a telescopic sleeve structure. It should also be noted that in this design, the upper end of the innermost sampling tube 11 is sealed to prevent soil from escaping from the sampling tube 11 during sample collection, while the remaining sampling tubes 11 are open at both ends to ensure that the sampling tube assembly 1 has axial telescopic capability.

[0050] like Figure 1 As shown, in this scheme, the pressure application component 2 is connected to the upper end of the outermost collection tube 11. During soil sample collection, the pressure application component 2 applies a stable axial force to the collection tube assembly 1, ensuring that the collection tube assembly 1 can be stably inserted into the soil at the sampling point to obtain a soil sample. It should be noted that, as... Figure 2 As shown, the pressure application component 2 in this solution includes a telescopic cylinder A21, which is connected to the upper end of the outermost collection cylinder 11 via a vertically extendable telescopic rod. It should be noted that, in some embodiments, a hoop is connected to the end of the telescopic rod of the telescopic cylinder A21. This hoop can be clamped onto the outermost side of the collection cylinder assembly 1 to achieve a fixed connection with it. It should be pointed out that the above-mentioned hoop connection method can further improve the stability of the collection cylinder assembly 1 and prevent it from cracking due to internal pressure when collecting soil samples.

[0051] In addition, to reduce contamination between upper and lower samples during soil sampling, and especially to prevent upper samples from being carried to the bottom by the collection tube 11, the collection tube assembly 1 in this solution extends downwards section by section (one collection tube 11 is one section) during soil sample collection, thereby reducing the distance the soil sample is carried downwards.

[0052] It is important to understand that, in specific implementations, there are various structures that enable the segmented insertion of each collection tube 11 in the aforementioned collection tube assembly 1. For example, by creating a certain amount of friction between each collection tube 11, and through the structure between the pressure application component 2 and the collection tube assembly 1, it is still possible to achieve a stepped expansion and contraction capability between each collection tube 11 during soil sample collection, which can, to some extent, prevent high levels of contamination of lower soil samples by upper soil samples during sample collection. However, this segmented insertion mode formed by the friction of the collection tube 11 itself is obviously uncontrollable, and the large friction between the collection tubes 11 will also affect the service life of the collection tube 11 itself.

[0053] To improve the orderly insertion of the collection tube 11 during soil sample collection (inserting them one by one from the inside out), such as Figure 3 , Figure 7 , Figure 8 As shown, this scheme has at least one brittle component 3 installed on the upper part of the outer sampling cylinder 11. Specifically, one end of the brittle component 3 abuts against the upper end face of the sampling cylinder 11 located inside the sampling cylinder 11. When the sampling cylinder assembly 1 is subjected to an axial force from the pressure application component 2, the sampling cylinder assembly 1 overcomes the resistance of the soil and enters the soil. At this time, the soil also exerts a reverse force on the sampling cylinder assembly 1. This reverse force is transmitted through the sampling cylinder 11 and acts on the brittle component 3. When the reverse force reaches the fracture threshold of the brittle component 3, the brittle component 3 itself undergoes brittle fracture. The fractured brittle component 3 loses its obstruction to the sampling cylinder 11, and the outer sampling cylinder 11 (the sampling cylinder 11 where the fractured brittle component 3 is located) can move relative to the inner sampling cylinder 11 and insert into the soil below, realizing the orderly insertion of the sampling cylinder 11. Preferably, in the above method, the fracture threshold of the brittle component 3 can be gradually increased from the inner brittle component 3 to the outer brittle component 3. When collecting soil samples, the longitudinal distribution structure of the collection tube 11 extends downward sequentially from the inside to the outside.

[0054] It should be noted that, as Figure 4 As shown, the advantage of the above sampling method is that when sampling is performed, the sampling tube assembly 1 is in contact with the surface of the sampling point. Then, when the pressure component 2 applies force, the sampling tube assembly 1 is driven by the pressure component 2 and inserted into the soil. At this time, only the innermost sampling tube 11 is in contact with the soil sample surface, while the inner surface of the outer sampling tube 11 will not be in contact with the upper soil layer, so the sample information of the upper soil layer will not be carried to the lower layer.

[0055] As the sampling tube assembly 1 continues to descend, once the top surface of the soil comes into contact with the top of the innermost sampling tube 11, the innermost sampling tube loses the space to continue descending. At this point, the pressure application component 2 tends to extend further downward, and the axial force acting on the outermost sampling tube 11 also increases. This increasing axial force is transmitted layer by layer through the rings of brittle components. When the axial force applied by the pressure application component 2 exceeds the fracture threshold of the innermost brittle component 3, the innermost brittle component 3 fractures, while the outermost brittle component remains intact because it has not reached the fracture threshold. At this point, the innermost sampling tube 11 loses its connection with the outermost (secondary outermost) sampling tube 11. That is, the secondary outermost sampling tube 11 will be able to move downward relative to the innermost sampling tube 11 under the force of the pressure application component 2, and the secondary outermost sampling tube 11 will continue to descend into the soil to collect the next layer of soil. It should be noted that, at this point, the inner surface of the inserted sampling tube 11 (the outermost sampling tube) does not come into contact with the soil until there is relative displacement with the innermost sampling tube. Therefore, it will not carry the uppermost layer of soil to the bottom of the sample during subsequent insertion. In other words, samples from higher layers will not be carried down by the outermost sampling tube 11, thus ensuring that sample data between the two soil sampling areas will not be cross-contaminated. It should also be noted that in this scheme, if the required number of soil sample layers is greater than two, subsequent sampling tubes 11 will repeat the movement pattern of the outermost sampling tube 11 described above. This ensures the independence of each soil sample layer; that is, each sampling tube can collect soil samples from an independent layer, preventing cross-contamination.

[0056] As a further optimization of the above implementation method, when setting the soil depth that each sampling tube 11 can collect, it can be set according to the thickness of each soil sample collected during soil sampling for nitrate data tracking and detection in pastoral areas. Specifically, as follows... Figure 5 , Figure 9 As shown, a travel groove 113 can be opened on the outer surface of the inner collection tube 11. The length of the travel groove 113 is the length of the soil sample thickness that the corresponding collection tube 11 needs to collect. At the same time, on the inner surface of the collection tube 11 sleeved on the outside of the collection tube 11, there is a slider 114 that slides in the travel groove 113. The depth that the outer collection tube 11 can be inserted is the distance that the slider 114 slides in the travel groove 113, that is, the depth of the soil sample that needs to be collected.

[0057] It should also be noted that although the collection tube 11 in this scheme adopts a stepped collection method, and the collected soil samples form a stepped cylindrical structure, this effectively reduces friction between the upper sample and the inner wall of the collection tube 11 containing the lower sample when pouring the sample out, thus reducing the chance of cross-contamination of the soil samples. However, this method of pouring the soil sample out of the entire cylindrical collection tube assembly 1 is still relatively inconvenient. Therefore, as... Figure 5 As shown, the collection tube 11 in this scheme is formed by two half-tubes 111 joined together to form a complete collection tube 11. The two half-tubes 111 are fixed together by bolts to prevent cracking during sample collection.

[0058] It should also be noted that in the above scheme, the brittle fracture threshold of the brittle component 3 is different between each layer of the collection cylinder 11. This means that multiple models of the brittle component 3 will be required, which is not conducive to the interchangeability and sharing of spare parts during operation. To improve this situation, such as... Figure 7 , Figure 8 As shown, in this scheme, multiple insertion slots 112 are formed on the upper surface of each acquisition component 11. Simultaneously, this scheme unifies the fracture threshold of individual brittle components 3. When it is necessary to ensure that the brittle fracture threshold is different for each layer, only different numbers of brittle components 3 need to be inserted, which is convenient and quick.

[0059] like Figure 6 As shown, in this design, the brittle component 3 specifically includes an insertion part 31, a brittle portion 32, and an abutment part 33. The brittle portion 32 is the part of the brittle component 3 that fractures when subjected to an axial force exceeding a threshold. In this design, the brittle portion 32 extends radially along the collection cylinder 11. The insertion part 31 is connected to one end of the brittle portion 32, and the abutment part 33 is connected to the other end of the brittle portion 32 to form an n-shaped structure. When performing the sample collection function, the insertion part 31, with a certain frictional force (greater than the brittle threshold), is inserted into the outer collection cylinder 11, while the abutment part 33 abuts against the upper end face of the inner collection cylinder 11. This allows the inner and outer collection cylinders 11 to move synchronously as a whole when the brittle component 3 has not fractured.

[0060] Furthermore, it should be noted that the brittle fracture portion 32 in this design can fracture after being subjected to a force exceeding its own threshold. However, whether the fractured portion 32 is smooth and whether the broken end can avoid the inner collection tube 11 will affect whether the outer collection tube 11 can smoothly slide relative to the inner collection tube 11. To this end, this design also provides a guide groove 34 on the brittle fracture portion 32. The guide groove 34 is located at the thinnest point of the brittle fracture portion 32, that is, to ensure that the location of the guide groove 34 is a stable fracture position of the brittle fracture portion 32, thereby guiding the brittle fracture portion 32 to not scrape against the surface of the inner collection tube 11 after fracture.

[0061] Furthermore, it should be noted that to improve the ease of installation of the brittle component 3 on the collection cylinder 11 and to prevent the broken brittle component 3 from being unable to be removed from the collection cylinder 11, a frictionless connection method can be used between the brittle component 3 and the collection cylinder 11. To accommodate this connection method, the insertion part 31 of the brittle component 3 in this design adopts an inclined insertion method. Specifically, the insertion part 31 has a certain angle with the axis of the collection cylinder 11. This angle ensures that even when the brittle component 3 is subjected to only axial force, it cannot slip out of the slot 112, achieving a frictionless self-locking effect.

[0062] like Figure 2 As shown, the pressure application component 2 in this scheme includes a telescopic cylinder A21 connected to the upper end face of the outermost collection cylinder 11. The telescopic rod end of the telescopic cylinder A21 is connected to the upper end face of the outermost collection cylinder 11. A pressure plate 22 is connected above the telescopic cylinder A21, and a pedal 23 is symmetrically connected to both ends of the pressure plate 22. It should be noted that, as... Figure 4 As shown, pedal 23 and pressure plate 22 cooperate to form a "U"-shaped structure. When soil samples need to be collected, the operator aligns the collection tube assembly 1 with the soil at the collection point, and then steps on both pedals 23. This causes the telescopic cylinder A21 to extend downwards, providing a stable pressure to ensure the normal operation of the device. Furthermore, it should be noted that after the collection tube 11 is inserted into the soil, the operator drives the telescopic cylinder B24 to extend, and the hook 25 is attached to the hanging ring 26. Then, the operator drives the telescopic cylinder B24 to retract, pulling the collection tube assembly 1 out of the soil. This extraction method effectively prevents the collected soil sample from slipping out and mixing with the surrounding soil during extraction.

[0063] It should be noted that this solution also discloses a sampling method adapted to a stratified sampling device for tracking and detecting nitrate data in pastoral soils, specifically including:

[0064] S1 Sampling Units: Several units with different grazing utilization methods (such as enclosed pastures, hayfields, rotational grazing pastures, collective pastures, etc.) and utilization intensities (no grazing, light grazing, moderate grazing, heavy grazing, etc.) are identified in the study area.

[0065] S2 Sampling tool selection: Select one of the stratified sampling devices for tracking and detecting nitrate data in pastoral soils from this scheme to collect soil samples;

[0066] S3 Determine the collection time: The collection time is during the greening period, the peak grass growth period, or before and after fertilization of some grasslands, in order to compare the dynamics of nitrate under different plant growth and human interference.

[0067] S4 Determine the collection location: Randomly select a representative location in the divided unit that is flat, has uniform vegetation growth, and avoids areas such as roads, fences, residential areas, and livestock drinking points;

[0068] S5 determines the sampling depth: collect soil samples at multiple depths such as 0~10cm, 10~10cm, and 20~30cm;

[0069] S6 Starts Collection: The telescopic cylinder A in the pressure application assembly extends, thereby driving the collection tube assembly to insert into the soil. As the soil surface contacts the innermost end of the collection tube, the collection tube has no more space to insert further. At this time, the telescopic cylinder A continues to extend, and the axial force on the collection tube assembly continues to increase. When the axial force rises to a threshold, the brittle component of the innermost ring breaks. The collection tube outside the innermost collection tube loses the connection constraint between it and the innermost collection tube, and can then continue to be inserted into the soil. At this time, the soil sample of the uppermost layer 0~10cm depth is collected. The second collection tube is inserted to collect the second layer of soil samples at a depth of 10~20cm. When the second collection tube is inserted to the bottom, as the telescopic cylinder A continues to apply pressure, the brittle component of the second ring also breaks. This cycle repeats until the soil samples of all depths are collected.

[0070] S7 Extracting Soil Samples: The telescopic cylinder B in the pressure application assembly extends downward, then the hook on the telescopic cylinder B connects with the hanging ring, and then the telescopic cylinder B retracts, thereby applying an axial upward pulling force to the innermost collection tube, thus extracting the collection tube assembly with the soil sample from the soil. It should be noted that when the telescopic cylinder B retracts, the telescopic cylinder A also retracts synchronously to ensure the smooth extraction of the collection tube assembly.

[0071] S8 Packaging Numbering: Remove the collected soil samples from the collection tube assembly and label them according to the time, location, and depth of the soil samples collected.

[0072] This solution, through the combination of the above structure and method, achieves one-step completion of soil stratification sampling, and also minimizes the contamination of the soil sample below when the sampling tube assembly is inserted.

[0073] It should be noted that after soil samples are collected, they are typically mixed, crushed, and analyzed according to the depth of the soil sample layer. Therefore, this method, through the layered descent of the collection tube in the collection tube assembly, effectively avoids the situation in existing straight-through collection tubes where the upper sample layer is carried to the bottom layer, thus causing sample contamination.

[0074] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A stratified sampling device for tracking and detecting nitrate data in pastoral soils, characterized in that: including a sampling cylinder assembly (1), including at least two sampling cylinders (11), and the at least two sampling cylinders (11) are coaxially sleeved and connected in a stacked manner; a pressing component (2), connected to the upper end of the outermost sampling cylinder (11) to apply an axial thrust to the sampling cylinder assembly (1) when collecting soil samples; fragile members (3), with multiple fragile members (3), and at least one fragile member (3) is arranged on the upper end surface of each outer sampling cylinder (11). One end of the fragile member (3) abuts against the upper end surface of the sampling cylinder (11) inside the sampling cylinder (11) where it is located. When the axial force received by the fragile member (3) from the abutted sampling cylinder (11) is greater than its own threshold, the fragile member (3) cracks, so that the sampling cylinder (11) where the fragile member (3) is located can be inserted downward into the soil under the axial force; the cracking thresholds of the fragile members (3) gradually increase from inside to outside according to their distribution positions on the sampling cylinder (11).

2. The stratified sampling device for tracking and detecting nitrate data in pastoral soils as described in claim 1, characterized in that: A plurality of insertion grooves (112) are formed on the sampling cylinder (11), and the plurality of insertion grooves (112) are circumferentially distributed on the upper end surface of the sampling cylinder (11).

3. The stratified sampling device for tracking and detecting nitrate data in pastoral soils as described in claim 1, characterized in that: The fragile member (3) is in an n shape, including a plugging part (31), a fragile part (32) and an abutting part (33). The fragile part (32) extends horizontally. One end of the fragile part (32) is connected to the plugging part (31), and the plugging part (31) can be detachably inserted into the sampling cylinder (11) where it is located. The other end of the fragile part (32) is connected to the abutting part (33).

4. The stratified sampling device for tracking and detecting nitrate data in pastoral soils as described in claim 3, characterized in that: A guiding groove (34) is formed on the fragile part (32).

5. The stratified sampling device for tracking and detecting nitrate data in pastoral soils as described in claim 4, characterized in that: The plugging part (31) is inserted into the sampling cylinder (11) at a certain angle with the axis of the sampling cylinder (11).

6. The stratified sampling device for tracking and detecting nitrate data in pastoral soils as described in claim 1, characterized in that: The sampling cylinder (11) includes two half cylinders (111), and the two half cylinders (111) are joined together and connected by bolts after being assembled.

7. A stratified sampling device for tracking and detecting nitrate data in pastoral soils as described in claim 6, characterized in that:

8. A stratified sampling device for tracking and detecting nitrate data in pastoral soils as described in claim 1, characterized in that: A travel groove (113) extending along the axis is formed on the outer surface of the inner sampling cylinder (11), and a slider (114) slidably arranged in the travel groove (113) is arranged on the inner side surface of the outer sampling cylinder (11). The pressing component (s2) includes a telescopic cylinder A (21) connected to the upper end surface of the outermost sampling cylinder (11). The upper end of the telescopic cylinder A (21) is connected to a pressing plate (22). Both ends of the pressing plate (22) are symmetrically connected to pedals (23). The pedals (23) are connected to the pressing plate (22) to form a "ji" shaped structure. A telescopic cylinder B (24) is further arranged on the pressing plate (22). A hook (25) is arranged at the lower end of the telescopic cylinder B (24). A hanging ring (26) capable of being hooked to the hook (25) is arranged on the end surface of the innermost sampling cylinder (11).

9. A layered sampling method for tracking and detecting soil nitrate data in pastoral areas, including S1 Dividing sampling units: determining several units with different grazing utilization methods and intensities in the research area; S2 Select sampling tool: Select the stratified sampling device for tracking and detecting nitrate data in pastoral soils as described in claim 8 to collect soil samples; S3 Determine the collection time: The collection time is during the greening period, the peak grass growth period, or before and after fertilization of some grasslands, in order to compare the dynamics of nitrate under different plant growth and human interference. S4 Determine the sampling location: Randomly select a representative location in the divided unit that is flat, has uniform vegetation growth, and avoids roads, fences, residential areas, and livestock drinking water areas; S5 determines the sampling depth: collect soil samples at multiple depths of 0~10cm, 10~10cm, and 20~30cm; S6 Starts Collection: The telescopic cylinder A in the pressure application assembly extends, thereby driving the collection tube assembly to insert into the soil. As the soil surface contacts the innermost end of the collection tube, the collection tube has no more space to insert further. At this time, the telescopic cylinder A continues to extend, and the axial force on the collection tube assembly continues to increase. When the axial force rises to a threshold, the brittle component of the innermost ring breaks. The collection tube outside the innermost collection tube loses the connection constraint between it and the innermost collection tube, and can then continue to be inserted into the soil. At this time, the soil sample of the uppermost layer 0~10cm depth is collected. The second collection tube is inserted to collect the second layer of soil samples at a depth of 10~20cm. When the second collection tube is inserted to the bottom, as the telescopic cylinder A continues to apply pressure, the brittle component of the second ring also breaks. This cycle repeats until the soil samples of all depths are collected. S7 Extracting Soil Samples: The telescopic cylinder B in the pressure application assembly extends downward, then the hook on the telescopic cylinder B connects with the hanging ring, and then the telescopic cylinder B retracts, thereby applying an axial upward pulling force to the innermost collection tube, thus pulling the collection tube assembly with the soil sample out of the soil. When the telescopic cylinder B retracts, the telescopic cylinder A also retracts synchronously to ensure the smooth extraction of the collection tube assembly. S8 Packaging Numbering: Remove the collected soil samples from the collection tube assembly and label them according to the time, location, and depth of the soil samples collected.

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