Collection system and collection method for greenhouse gas discharged by soil-crops

Abstract

The invention discloses a soil-crop emission greenhouse gas collection system and a collection method, and relates to the technical field of gas collection. The soil-crop emission greenhouse gas collection system comprises a first gas collection box, a second gas collection box and a gas collection assembly, a hollow cabin is nested in a first base of the first gas collection box, the hollow cabin is provided with a lower cavity penetrating in the vertical direction, a first box cover is provided with an upper cavity penetrating in the vertical direction, and the upper cavity and the lower cavity are correspondingly communicated to form a channel for crop plant growth; gas collection assemblies are arranged on the outer sides of the first gas collection box and the second gas collection box respectively and are used for collecting gas in the corresponding first gas cavity and the second gas cavity. According to the invention, the data of the greenhouse gases emitted by the soil-crop system can be obtained, the greenhouse gases emitted by the soil and crops can be distinguished, and the pertinence and accuracy of the data are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas collection, and particularly to a greenhouse gas collection system and method for soil-crop emissions. Background Art

[0002] The soil-crop system is the most important carbon pool in the terrestrial ecosystem and the main source of carbon dioxide emissions into the atmosphere. Even a slight change in soil organic carbon may significantly affect the atmospheric carbon dioxide concentration and climate dynamics. Distinguishing between heterotrophic respiration from soil microbial activities and autotrophic respiration from plant roots and rhizosphere microbial activities is the premise and key to exploring the response of carbon dioxide emissions to changes in environmental conditions, and is of great significance for understanding the relationship between the carbon cycle and climate change. Therefore, the collection and measurement of carbon dioxide from soil sources and crop sources within a region are important links in studying the soil carbon-nitrogen cycle and carbon emission accounting within the region.

[0003] The closed static chamber method is a commonly used method for collecting and measuring greenhouse gases such as carbon dioxide emission fluxes, and is widely used because of its simple operation. However, traditional closed static chambers generally have a closed lid that is directly buckled on the base fixed in the sample plot. For tall crops in dryland ridge cropping environments, due to the influence of crop plants, it is only possible to collect samples at the edge by avoiding the crop plants, and it is impossible to obtain accurate data on greenhouse gas emissions such as carbon dioxide from the soil-crop system, nor can the greenhouse gases such as carbon dioxide emitted by the soil and crops be distinguished, which seriously affects the pertinence and accuracy of the data and hinders the scientific understanding of the carbon cycle process and the accurate accounting of carbon emissions.

[0004] In view of the problems existing in the above-mentioned prior art, those skilled in the art urgently need a greenhouse gas collection system and method for soil-crop emissions. Summary of the Invention

[0005] The purpose of the present invention is to provide a greenhouse gas collection system and method for soil-crop emissions to solve the problems existing in the above-mentioned prior art, which can obtain data on greenhouse gas emissions from the soil-crop system, and can distinguish the greenhouse gases emitted by the soil and crops, improving the pertinence and accuracy of the data.

[0006] To achieve the above purpose, the present invention provides the following solutions:

[0007] In a first aspect, the present invention provides a soil-crop greenhouse gas collection system, comprising a first gas collection box, a second gas collection box and a gas collecting assembly; the first gas collection box comprises a first base, a first box cover and a hollow cabin, the first base is opened at both ends in the vertical direction, the lower part of the first base is used to be pre-buried in the soil, the hollow cabin is nested inside the first base, the hollow cabin has a lower cavity that passes through in the vertical direction, the first box cover has an upper cavity that passes through in the vertical direction, the upper cavity is connected to the lower cavity correspondingly to form a channel for crop plant growth; the bottom end of the first box cover is used to be sealed and connected to the top of the first base and the top of the hollow cabin, the first box cover, the first base and the hollow cabin together form a first gas cavity; the second gas collection box has a second gas cavity; the gas collecting assemblies are respectively provided on the outer sides of the first gas collection box and the second gas collection box, and the gas collecting assemblies are used to collect the gases in the corresponding first gas cavity and the second gas cavity.

[0008] In some embodiments, the first box cover includes two split box covers, and the upper cavity is surrounded by the opposite ends of the two split box covers; the top of the first base and the top of the hollow cabin body are provided with a first annular groove, and the first annular groove extends and closes along the top edge of the first base and the top edge of the hollow cabin body; the bottom end of the split box cover is inserted into the first annular groove, and the first annular groove can water-seal the joint between the split box cover and the first base and the hollow cabin body; and / or the second gas collection box includes a second base and a second box cover, the second base is opened at both ends in the vertical direction, the lower part of the second base is used to be pre-buried in the soil, and the second box cover and the second base are combined to form the second gas cavity; the top of the second base is provided with a second annular groove, and the bottom end of the second box cover is inserted into the second annular groove, the second annular groove extends and closes along the top edge of the second base, and the second annular groove can water-seal the joint between the second base and the split box cover.

[0009] In some embodiments, the gas collecting assembly includes a gas extraction device, a gas collecting device and a three-way valve; one end of the three-way valve is connected to the corresponding first gas collection box or the second gas collection box, and the other two ends are respectively connected to the gas extraction device and the gas collecting device; when the three-way valve is in a first working state, the gas extraction device is connected to the corresponding first gas collection box or the second gas collection box, and is used to extract gas from the first gas cavity or the second gas cavity; when the three-way valve is in a second working state, the gas extraction device is connected to the gas collecting device, and is used to transport the extracted gas to the gas collecting device.

[0010] In some embodiments, the gas collecting assembly includes an airbag, a driving assembly, and a gas collecting pipeline. The driving assembly is used to control the inflation and inhalation or contraction and exhalation of the airbag; before gas collection, the airbag is in an inflated state, and the airbag is communicated with the corresponding first gas collection box or the second gas collection box; during gas collection, the airbag can also be communicated with the gas collecting pipeline to transport gas into the gas collecting pipeline.

[0011] In some embodiments, a temperature adjustment loop is further included. The temperature adjustment loops are respectively and communicatively arranged on the outer sides of the first gas collection box and the second gas collection box; a circulation fan and a temperature control device are arranged in the temperature adjustment loop. The circulation fan is used to circulate the gas in the first gas chamber or the second gas chamber, and the temperature control device is used to adjust the temperature of the circulated gas.

[0012] In some embodiments, the hollow cabin body includes a plurality of outer vertical plates, a plurality of inner vertical plates, a first elastic connection part, and a second elastic connection part. The side ends of the plurality of outer vertical plates are sequentially fixedly connected to form the outer layer shell of the hollow cabin body, and the side ends of the plurality of inner vertical plates are sequentially connected to form the inner layer shell of the hollow cabin body. The inside of the inner layer shell is the lower cavity; the outer layer shell and the inner layer shell are connected through the first elastic connection part, and the side ends of two adjacent inner vertical plates are connected through the second elastic connection part, so that the size of the lower cavity can be adaptively adjusted.

[0013] In some embodiments, the driving assembly includes a driving part, a support rod, an annular sleeve, and an umbrella-shaped support structure; the annular sleeve is sleeved outside the support rod, the driving part is used to drive the annular sleeve to slide along the length direction of the support rod, the umbrella-shaped support structure is respectively hinged to the annular sleeve and the support rod, and the umbrella-shaped support structure abuts against the inner wall of the airbag; the annular sleeve can drive the umbrella-shaped support structure to open or contract. When the umbrella-shaped support structure is in an open state, the airbag is in a corresponding inflated state; when the umbrella-shaped support structure is in a contracted state, the airbag is in a contracted state under its own elastic force.

[0014] In a second aspect, the present invention provides a method for collecting greenhouse gases emitted from soil-crops, comprising the following steps: Step S1: bury the lower part of the first base of the first gas collection box in the soil, and plant crops in the soil within the hollow cabin of the first base, and bury the lower part of the second base of the second gas collection box in the soil; Step S2: before gas collection, hermetically connect the bottom end of the first box cover to the top end of the first base and the top end of the hollow cabin, and hermetically connect the bottom end of the second box cover to the top end of the second base; Step S3: after reaching the set gas collection time, use the gas collection assembly to collect the gas in the first gas chamber of the first gas collection box to obtain the first flux of greenhouse gases emitted from soil-crops, use the gas collection assembly to collect the gas in the second gas chamber of the second gas collection box to obtain the second flux of greenhouse gases emitted from the soil, and obtain the flux of greenhouse gases emitted by the crops according to the first flux and the second flux.

[0015] In some embodiments, the gas collection assembly includes an airbag, a driving assembly, and a gas collection pipeline. Before gas collection, the airbag is in an inflated state, and the driving assembly is used to control the airbag to expand and inhale gas or contract and exhaust gas; in the step S3, the step of using the gas collection assembly to collect the gas in the first gas chamber or the second gas chamber includes: after reaching the set gas collection time, the driving assembly controls the airbag to perform the first contraction to discharge the gas in the airbag into the corresponding first gas chamber or the second gas chamber for mixing; the driving assembly controls the airbag to expand and inhale the mixed gas; connect the airbag to the gas collection pipeline, and the driving assembly controls the airbag to perform the second contraction to transport the mixed gas to the gas collection pipeline.

[0016] In some embodiments, temperature adjustment circuits are respectively arranged on the outer sides of the first gas collection box and the second gas collection box, and a circulation fan and a temperature control device are arranged in the temperature adjustment circuit; the method further includes: obtaining a first temperature value inside the first gas collection box or the second gas collection box, and obtaining a second temperature value outside to obtain the difference between the first temperature value and the second temperature value; controlling the wind speed of the circulation fan and the power of the temperature control device according to the magnitude of the difference.

[0017] The present invention has achieved the following technical effects compared with the prior art:

[0018] In the soil-crop greenhouse gas collection system and collection method of the present invention, the first gas collection box is a gas collection box for growing crops. A nested base is formed by arranging a hollow cabin inside the first base. The inside of the hollow cabin is used for growing crops. The greenhouse gas emitted by the soil-crop can be collected through the first gas collection box. The hollow cabin has a lower cavity extending vertically and penetratingly, and the upper cavity of the first box cover and the lower cavity form a channel for the growth of crop plants. Therefore, when collecting gas in the present invention, there is no need to collect gas at the edge of the crop plants. The crop plants can be directly nested in the hollow cabin or crop seeds can be sown in the hollow cabin, so as to obtain the data of the greenhouse gas emitted by the soil-crop system. The second gas collection box of the present invention is a gas collection box without growing crops, which is used to collect the gas emitted by the soil. By subtracting the greenhouse gas flux collected from the second gas collection box from the greenhouse gas flux collected from the first gas collection box, the greenhouse gas flux emitted by the crops can be obtained. Therefore, the present invention can distinguish the greenhouse gas emitted by the soil and the crops, improve the pertinence and accuracy of the data, and realize the accurate accounting of the greenhouse gas flux emitted by the soil, soil-crop and crops.

[0019] Furthermore, in the present invention, a first annular groove is provided at the top of the first base and the hollow cabin, and water is injected into the first annular groove for sealing to improve the overall airtightness of the first gas collection box; a second annular groove is provided at the top of the second base, and water is injected into the second annular groove for sealing to improve the overall airtightness of the second gas collection box; thereby, the accuracy of the collected data can be improved.

[0020] Furthermore, when collecting gas in the present invention, the gas in the corresponding gas collection box can be extracted through an air extraction device, and the extracted gas can be transported to a gas collection device through the air extraction device, which has the effect of simple operation. The present invention can also be such that the airbag is in an inflated state before gas collection, and the airbag is contracted during gas collection to discharge the gas in the airbag into the corresponding gas chamber for mixing, and then the airbag is inflated to inhale the mixed gas, and then the airbag is contracted again to transport the mixed gas to the gas pipeline; in this way, the airbag is in an inflated state before gas collection and in a contracted state after gas collection. The air pressure in the gas chamber is balanced by the airbag. Before and after gas collection, the air pressure change in the gas chamber is small. Therefore, the present invention can avoid the influence of the gas collection process on the air pressure in the gas chamber and avoid the influence of the air pressure change on the accuracy of the collected data. Moreover, when collecting gas, the gas in the airbag is first mixed evenly with the gas in the gas chamber, which improves the accuracy of the collected data.

[0021] Furthermore, the present invention is provided with a temperature regulation circuit communicated with the gas chamber outside the gas collection box. The gas in the gas chamber is circulated by a circulation fan in the circuit, and the temperature of the circulated gas is regulated by a temperature control device. By setting the temperature regulation circuit outside the gas collection box, the present invention can quickly regulate the temperature inside the gas collection box by adjusting the wind speed of the circulation fan and the operating power of the temperature control device, so that the temperature inside and outside the gas collection box is kept consistent or the temperature inside the gas collection box is kept relatively stable, improving the accuracy of the collected data. Moreover, the separately provided temperature regulation circuit can avoid the influence of the temperature control device on the soil and crop roots inside the gas collection box.

[0022] Furthermore, the hollow cabin of the present invention includes a plurality of outer baffles, a plurality of inner baffles and elastic connection parts. The outer shell formed by the plurality of outer baffles and the inner shell formed by the plurality of inner baffles are connected by a first elastic connection part, and adjacent two inner baffles are connected by a second elastic connection part. Specifically, the elastic connection can be realized by a first elastic connection part made of rubber or a second elastic connection part made of rubber, so that the size of the lower cavity surrounded by the plurality of inner baffles can be adjusted adaptively. As the crop plants grow, the volume of the lower cavity increases accordingly, avoiding affecting the growth of the crop plants. Moreover, the hollow cabin of the present invention can also be applicable to nesting different crop plants, with strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 Structural schematic diagram of the first gas collection box in some embodiments of the present invention;

[0025] Figure 2 Structural schematic diagram of the second gas collection box in some embodiments of the present invention;

[0026] Figure 3 Structural schematic diagram of the first base in some embodiments of the present invention;

[0027] Figure 4 Schematic diagram of the soil-crop greenhouse gas emission collection system in some embodiments of the present invention;

[0028] Figure 5 Structural schematic diagram of the first box cover in some embodiments of the present invention;

[0029] Figure 6 Structural schematic diagram of a driving component in some embodiments of the present invention;

[0030] Figure 7 is Figure 6 Partial enlarged view at location A in;

[0031] Figure 8 Schematic diagram of the installation positions of a circulating fan and a temperature control device in some embodiments of the present invention;

[0032] Figure 9 Main step flowchart of a method for collecting greenhouse gas emissions from soil - crops in some embodiments of the present invention;

[0033] Figure 10 One of the curve graphs showing the change of the concentration of carbon dioxide emitted from ridge - cultivated black soil - corn with the gas collection time in the application of the present invention;

[0034] Figure 11 Two of the curve graphs showing the change of the concentration of carbon dioxide emitted from ridge - cultivated black soil - corn with the gas collection time in the application of the present invention;

[0035] Figure 12 Three of the curve graphs showing the change of the concentration of carbon dioxide emitted from ridge - cultivated black soil - corn with the gas collection time in the application of the present invention;

[0036] Figure 13 Four of the curve graphs showing the change of the concentration of carbon dioxide emitted from ridge - cultivated black soil - corn with the gas collection time in the application of the present invention.

[0037] In the figure: 1 - First gas collection box; 2 - Second gas collection box; 3 - Gas collection component; 4 - Temperature regulation loop; 5 - Temperature sensor; 6 - Analyzer; 7 - Control system; 11 - First box cover; 12 - First base; 13 - Hollow cabin; 14 - First annular groove; 21 - Second box cover; 22 - Second base; 23 - Second annular groove; 31 - Air extraction device; 32 - Gas collection device; 33 - Three - way valve; 34 - Airbag; 35 - Driving component; 36 - Gas collection pipeline; 41 - Circulating fan; 42 - Temperature control device; 121 - Communication hole; 131 - Outer vertical plate; 132 - Inner vertical plate; 133 - First elastic connection part; 351 - Support rod; 352 - Annular sleeve; 353 - Umbrella - shaped support structure. Specific embodiments

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0039] The object of the present invention is to provide a soil-crop greenhouse gas emission collection system and a collection method to solve the problems existing in the prior art, which can obtain accurate data on the greenhouse gas emissions of the soil-crop system, and can distinguish the greenhouse gas emissions from the soil and crops, and the pertinence and accuracy of the data are high.

[0040] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Embodiment 1

[0042] This embodiment discloses a soil-crop greenhouse gas emission collection system, as shown in Figure 1 and Figure 2 , which includes a first gas collection box 1, a second gas collection box 2, and a gas collection component 3. Among them, the first gas collection box 1 is in a cuboid structure for collecting greenhouse gases such as carbon dioxide emitted by the soil-crop, and the second gas collection box 2 is in a cuboid structure for collecting greenhouse gases such as carbon dioxide emitted by the soil. Here, the greenhouse gases emitted by the soil-crop should be understood as the greenhouse gases jointly emitted by soil microbial activities, crop roots, and root microbial activities, and the greenhouse gases emitted by the soil should be understood as the greenhouse gases emitted by soil microbial activities.

[0043] It should be noted that in this embodiment, the first gas collection box 1 and the second gas collection box 2 are set in a cuboid structure as an example for illustration. Those skilled in the art can also set the first gas collection box 1 and the second gas collection box 2 in other shapes, and the present invention does not make specific limitations.

[0044] Referring to Figure 1 , the first gas collection box 1 includes a first box cover 11, a first base 12, and a hollow cabin 13. Both the upper and lower ends of the first base 12 are open; a hollow cabin 13 is nested inside the first base 12, and the first base 12 and the hollow cabin 13 form a nested base. The hollow cabin 13 is square and both its upper and lower ends are open. The outer wall of the hollow cabin 13 is connected to the inner wall of the first base 12, and the hollow cabin 13 divides the first base 12 into two mutually connected left and right parts. Specifically, as shown in Figure 1As shown in the figure, a communication hole 121 is provided between the left and right parts inside the first base 12. The first box cover 11 includes two split box covers. An upper cavity is formed by enclosing the relative ends of the two split box covers. Specifically, grooves are formed at the relative ends of the two split box covers, and the grooves at the relative ends of the two split box covers are combined to enclose the upper cavity. The upper cavity is vertically penetrated. The hollow cabin 13 has a lower cavity vertically penetrated.

[0045] It should be noted that the hollow cabin 13 of this embodiment can be nested in the middle of the first base 12; and in this embodiment, the hollow cabin 13 is taken as an example of being set in a square shape. Those skilled in the art can also set the hollow cabin 13 in other shapes, and the present invention does not make specific limitations.

[0046] When gas collection is required, the first box cover 11 is buckled on the nested base. The bottom end of the first box cover 11 is hermetically connected to the top end of the first base 12 and the top end of the hollow cabin 13. The lower part of the nested base is buried in the soil of the crop to be planted. At this time, the first box cover 11, the first base 12 and the hollow cabin 13 enclose a closed first gas chamber, which is used to collect the greenhouse gases jointly emitted by the soil-crop system. And the upper cavity of the first box cover 11 and the lower cavity of the hollow cabin 13 have the same size and jointly form a channel for the growth of crop plants. The channel is vertically penetrated from top to bottom and is not connected to the first gas chamber.

[0047] The first base 12 is placed across the ridge platform, and the length is equal to the ridge width or an integer multiple of the ridge width, so that the two ends of the first base 12 in the length direction reach the center lines of the ridge ditches on both sides of the ridge platform, and the lower part of the first base 12 is buried in the bare land soil to be planted and fixed in the sample plot. Crop seeds or nested crop plants are sown in the hollow cabin 13 so that the crop plants can grow along the channel.

[0048] It should be noted that in this embodiment, the first box cover 11 is taken as an example of including two split box covers. The first box cover 11 can also be an integral box cover and an upper cavity is formed in the middle of the integral box cover.

[0049] Refer to Figure 2As shown in the figure, the second gas collection box 2 includes a second box cover 21 and a second base 22. The second box cover 21 is an integral box cover with an opening at its lower end, and the second base 22 is an open base with openings at both its upper and lower ends. Place the second base 22 across the ridge platform, with its length equal to or an integer multiple of the ridge width, such that the two ends in the length direction of the second base 22 reach the centerlines of the ridge ditches on both sides of the ridge platform, and bury the lower part of the second base 22 in the bare soil without crop planting and fix it in the sample plot; this can make the placement position of the second base 22 similar to that of the first base 12, avoiding the influence of different placement positions on the accuracy of the collected data. Before gas collection, buckle the second box cover 21 on the second base 22, and make a sealed connection between the bottom end of the second box cover 21 and the top end of the second base 22, so that the second box cover 21 and the second base 22 are combined to enclose an airtight second gas chamber for collecting greenhouse gases emitted from the soil.

[0050] Continue to refer to Figure 1 , at the top end of the first base 12 and the top end of the hollow cabin 13 of this embodiment, a first annular groove 14 is formed. The first annular groove 14 extends along the top edge of the first base 12 and the top edge of the hollow cabin 13 and is connected and closed. The bottom ends of the two split box covers of the first box cover 11 can be correspondingly inserted into the first annular groove 14. By injecting water into the first annular groove 14, a water seal can be formed at the connection between the first box cover 11, the first base 12, and the hollow cabin 13 to form an airtight first gas chamber, avoiding the communication between the gas in the first gas chamber and the outside world and ensuring the accuracy of the collected data. And a snap connection and fixation form can be adopted between the bottom end of the first box cover 11 and the inner wall of the first annular groove 14 to improve the connection and fixation effect.

[0051] Continue to refer to Figure 2 , at the top end of the second base 22 of this embodiment, a second annular groove 23 is formed. The second annular groove 23 extends along the top edge of the second base 22 and is connected and closed. The bottom end of the second box cover 21 can be correspondingly inserted into the second annular groove 23. By injecting water into the second annular groove 23, a water seal can be formed at the connection between the second box cover 21 and the second base 22 to form an airtight second gas chamber, avoiding the communication between the gas in the second gas chamber and the outside world and ensuring the accuracy of the collected data. And a snap connection and fixation form can be adopted between the bottom end of the second box cover 21 and the inner wall of the second annular groove 23 to improve the connection and fixation effect.

[0052] In this embodiment, gas collection components 3 are respectively arranged on the outer sides of the first gas collection box 1 and the second gas collection box 2. The gas collection component includes an air extraction device 31, a gas collection device 32, and a three-way valve 33. Air outlet ports are respectively arranged on the first box cover 11 and the second box cover 21. An oil circuit connector is sleeved on the air outlet port, and the oil circuit connector is communicated with the gas cavity and the outside through a gas guide pipe. A stop valve is installed on the gas guide pipe. The stop valve is a three-way valve 33, and the other two ends of the three-way valve 33 are respectively connected with the air extraction device 31 and the gas collection device 32. When the three-way stop valve 33 is in the first working state, the air extraction device 31 is communicated with the corresponding gas cavity for extracting gas. When the three-way valve 33 is in the second working state, the air extraction device 31 is communicated with the gas collection device 32 for transporting the extracted gas into the gas collection device 32 for collection.

[0053] It should be noted that the air extraction device 31 in this embodiment can be a syringe or other devices with air extraction functions, and the gas collection device 32 can be a gas cylinder, a gas bag, or other devices with gas collection functions. And the gas guide pipe in this embodiment can adjust the inner diameter and material of the air pipe according to the amount of gas to be collected. The oil circuit connector can also be replaced by other components similar to pipes, as long as the effect of connecting the outside and the gas cavity is achieved.

[0054] After the sampling is completed, the gas collected in the gas collection device 32 is measured. The greenhouse gas flux emitted by the soil-crop can be obtained according to the gas collected from the first gas cavity. The greenhouse gas flux emitted by the soil can be obtained according to the gas collected from the second gas cavity. The difference between the greenhouse gas flux emitted by the soil-crop minus the greenhouse gas flux emitted by the soil is calculated as the greenhouse gas flux emitted by the crop. Here, the greenhouse gas emitted by the crop should be understood as the greenhouse gas emitted by the crop roots and the activities of the root microorganisms.

[0055] In this embodiment, temperature detection ports are respectively opened on the first box cover 11 and the second box cover 21. A rubber plug is sleeved on the temperature detection port, and the detection end of the temperature sensor 5 is inserted into the rubber plug for detecting the gas temperature in the corresponding gas cavity.

[0056] In this embodiment, the first box cover 11, the first base 12, the hollow cabin 13, the second box cover 21, and the second base 22 are all made of stainless steel or corrosion-resistant metal. And a reflective heat-insulating layer is pasted on the outer sides of the first box cover 11 and the second box cover 21. By pasting the reflective heat-insulating layer, the temperature in the gas cavity can be maintained relatively stable, avoiding rapid heating due to direct sunlight or rapid cooling due to large changes in the external temperature. The reflective heat-insulating layer can be a self-adhesive aluminum foil heat-insulating cotton, which is convenient to paste and has a good temperature-maintaining effect.

[0057] The gas collection system of this embodiment can be used for sampling carbon dioxide or other greenhouse gases emitted by dryland ridge crops, and is suitable for scientific research institutions and environmental monitoring departments to collect and sample greenhouse gases emitted by dryland soil-crops. It can also be used for sampling greenhouse gases emitted by farmland in the wild. The gas collection system of this embodiment includes a set of special soil-crop co-emission greenhouse gas collection devices, namely the first gas collection box 1, and a set of special soil-emission greenhouse gas collection devices, namely the second gas collection box 2. These two sets of devices are used in combination, and the sizes of the two sets of devices are ensured to be the same to reduce the error in calculating the greenhouse gas flux emitted by crops by the difference method. When in use, before planting crops, the first base 12 and the second base 22 are respectively buried in the soil across the ridge platform. Crop seeds are sown in the hollow cabin 13 in the middle of the first base 12 to ensure that at least one crop plant can be nested. Before gas collection, the two split box covers of the first box cover 11 are spliced and buckled into the first annular groove 14 provided at the top of the first base 12 and the top of the hollow cabin 13, and the second box cover 21 is buckled into the second annular groove 23 provided at the top of the second base 22. Water is injected into the first annular groove 14 and the second annular groove 23 to form a sealed first gas chamber and a second gas chamber. After standing for the corresponding sealed time according to the experimental requirements, the three-way valve 33 is adjusted to the first working state, and the gas in the gas chamber is extracted by the air extraction device 31 through the gas guide pipe. After extracting a sufficient amount of gas, the three-way valve 33 is adjusted to the second working state, and the air extraction device 31 can transport the extracted gas into the gas collection device 32. After the sampling is completed, the gas in the gas collection device 32 is measured to obtain the greenhouse gas flux emitted by the soil-crop and the greenhouse gas flux emitted by the soil. The difference obtained by subtracting the greenhouse gas flux emitted by the soil from the greenhouse gas flux emitted by the soil-crop is the greenhouse gas flux emitted by the crop.

[0058] Embodiment 2

[0059] This embodiment discloses a greenhouse gas collection system for soil-crop emissions. The difference between this embodiment and Embodiment 1 is that as Figures 4 to 8 shown, the gas collection assembly 3 of this embodiment includes an airbag 34, a driving assembly 35, and a gas collection pipeline 36; the driving assembly 35 can control the airbag 34 to expand for inhalation or contract for exhalation. The airbag 34 is connected to the corresponding gas collection box, and a cut-off valve is provided between them. The airbag 34 is also connected to the gas collection pipeline 36, and a cut-off valve is provided between them.

[0060] Before gas collection, the airbag 34 is in communication with the corresponding gas chamber and the airbag 34 is in an inflated state; during gas collection, the driving assembly 35 controls the airbag 34 to contract to discharge the gas therein into the gas chamber for mixing, and then the driving assembly 35 controls the airbag 34 to expand to inhale the mixed gas; the working state of the corresponding stop valve is adjusted so that the airbag 34 is disconnected from the gas chamber and is in communication with the gas collecting pipeline 36, and the driving assembly 36 controls the airbag to contract to transport the mixed gas into the gas collecting pipeline 36.

[0061] It should be noted that three gas collecting assemblies are respectively arranged on the outer sides of the first gas collecting tank 1 and the second gas collecting tank 2 in this embodiment. Those skilled in the art can specifically set the number of gas collecting assemblies, and the present invention does not make specific limitations.

[0062] The airbag 34 in this embodiment is in an inflated state before gas collection. Specifically, the airbag 34 is in an inflated state before the box cover is installed on the base. After gas collection, the airbag 34 is in a contracted state. The change in the state of the airbag 34 can keep the air pressure in the gas chamber stable and avoid the change in the air pressure in the gas chamber before and after gas collection; and when collecting gas, the gas in the airbag 34 is first mixed evenly with the gas in the gas chamber, which can improve the accuracy of the collected data.

[0063] In this embodiment, as Figure 4 shown, the gas collection system further includes an analyzer 6 and a control system 7. The gas collecting pipelines 36 of multiple gas collecting assemblies 3 are all connected to the analyzer 6 for measurement, and the control system 7 is connected to the analyzer 6 to receive the detection data of the analyzer 6. The control system 7 is also connected to the driving assemblies 35 of multiple gas collecting assemblies 3 to control the working state of the driving assemblies 35, and further control the airbag 34 to expand or contract.

[0064] In this embodiment, as Figure 7As shown, the driving assembly 35 includes a support rod 351, an annular sleeve 352, an umbrella-shaped support structure 353, and a driving part (not shown in the figure). Air collection ports are formed on both the first box cover 11 and the second box cover 21. One end of the support rod 351 is connected to the inner wall of the air collection port, and the other end is an extended end that extends to the outside; the open end of the airbag 34 is connected to the outer wall of the air collection port; the annular sleeve 352 is sleeved outside the support rod 351; the umbrella-shaped support structure 353 is respectively hinged to the extended end of the support rod 351 and the annular sleeve 352. Specifically, the umbrella-shaped support structure 353 includes a plurality of long hinge rods and short hinge rods. The two ends of the short hinge rod are respectively hinged to the annular sleeve 352 and one end of the long hinge rod, and the other end of the long hinge rod is hinged to the extended end of the support rod 351; the driving part can drive the annular sleeve 352 to slide along the length direction of the support rod 351, and then the annular sleeve 352 can drive the umbrella-shaped support structure 353 to open or contract; the umbrella-shaped support structure 353 abuts against the inner wall of the airbag 34. When the umbrella-shaped support structure 353 opens, the airbag 34 is in an inflated state correspondingly, and when the umbrella-shaped support structure 353 contracts, the airbag 34 is in a contracted state under its own elastic action.

[0065] Those skilled in the art can set the inflation volume of the airbag 34 and the number of airbags 34 according to the amount of gas to be collected, and the present invention does not make specific limitations.

[0066] In this embodiment, temperature adjustment circuits 4 are respectively arranged on the outer sides of the first gas collection box 1 and the second gas collection box 2. Both ends of the temperature adjustment circuit 4 communicate with the corresponding gas chambers. A circulation fan 41 and a temperature control device 42 are arranged in the temperature adjustment circuit 4. The circulation fan 41 can circulate the gas in the gas chamber, and the temperature control device 42 can adjust the temperature of the circulated gas. The temperature adjustment here includes two modes: heating adjustment and cooling adjustment.

[0067] And it should be noted that when mixing the gas in the airbag 34 with the gas in the gas chamber evenly, the effect of mixing evenly can be enhanced by starting the circulation fan 41.

[0068] The control system 7 is connected to the circulation fan 41 for adjusting the wind speed of the circulation fan 41, and the control system 7 is also connected to the temperature control device 42 for controlling the operating power of the temperature control device 42. In this embodiment, by controlling the wind speed of the circulation fan 42 and the operating power of the temperature control device 42, the effect of quickly adjusting the temperature of the gas in the gas chamber can be achieved, and the influence of the temperature control device 42 on the soil and crop roots in the gas collection box can be avoided.

[0069] Embodiment Three

[0070] This embodiment provides a soil-crop greenhouse gas emission collection system. The difference between this embodiment and Embodiment One or Embodiment Two is that: asFigure 3 As shown in the figure, the hollow cabin 13 of this embodiment includes a plurality of outer vertical plates 131, a plurality of inner vertical plates 132, a first elastic connection part 133, and a second elastic connection part (not shown in the figure). The side ends of the plurality of outer vertical plates 131 are fixedly connected in sequence to form the outer shell of the hollow cabin 13, and this outer shell is fixedly connected to the inner side wall of the first base 12; the side ends of the plurality of inner vertical plates 132 are connected in sequence to form the inner shell of the hollow cabin 13, and the interior of this inner shell is the lower cavity; the outer shell and the inner shell are connected through the first elastic connection part 133, and the side ends of two adjacent inner vertical plates 132 are connected through the second elastic connection part; the first elastic connection part 133 and the second elastic connection part can be rubber connectors with certain elasticity, so that the volume of the enclosed lower cavity can be adjusted adaptively. As the diameter of the crop plants planted in the hollow cabin 13 gradually increases, the volume of the lower cavity increases accordingly to avoid affecting the growth of the crop plants; and the hollow cabin of this embodiment can be adapted to plant crop plants with different diameters, and has strong applicability.

[0071] It should be noted that the first elastic connection part 133 and the second elastic connection part of this embodiment can be made of rubber material, and can also be made of other elastic materials. The present invention does not make specific limitations.

[0072] Embodiment 4

[0073] This embodiment discloses a method for collecting greenhouse gas emissions from soil-crops, using the soil-crop greenhouse gas collection system of the above-mentioned Embodiment 2. As Figure 9 shown, it includes the following steps:

[0074] Step S1: Bury the lower part of the first base 12 of the first gas collection box 1 in the soil, and plant the crops in the soil in the hollow cabin 13 inside the first base 12, and bury the lower part of the second base 22 of the second gas collection box 2 in the soil;

[0075] Step S2: Before gas collection, hermetically connect the bottom end of the first box cover 11 to the top end of the first base 12 and the top end of the hollow cabin 13, and hermetically connect the bottom end of the second box cover 21 to the top end of the second base 22;

[0076] Step S3: After reaching the set gas collection time, use the gas collection component 3 to collect the gas in the first gas chamber to obtain the first flux of greenhouse gas emissions from soil-crops, use the gas collection component 3 to collect the gas in the second gas chamber to obtain the second flux of greenhouse gas emissions from soil, and obtain the flux of greenhouse gas emissions from crops according to the first flux and the second flux.

[0077] In some embodiments, before gas collection, the airbag 34 is in an inflated state; in the above step S3, the step of using the gas collection assembly 3 to collect the gas in the first gas chamber or the second gas chamber includes:

[0078] After reaching the set gas collection time, the driving assembly 35 controls the airbag 34 to perform the first contraction, discharging the gas in the airbag 34 into the corresponding first gas chamber or the second gas chamber for mixing; the driving assembly 35 controls the airbag 34 to expand and inhale the mixed gas; the airbag 34 is communicated with the gas collection pipeline 36, and the driving assembly 35 controls the airbag 34 to perform the second contraction to transport the mixed gas into the gas collection pipeline 36.

[0079] In some embodiments, the gas collection method of this embodiment further includes:

[0080] Obtain the first temperature value inside the first gas collection box 1 or the second gas collection box 2, and obtain the second temperature value outside, obtaining the difference between the first temperature value and the second temperature value; control the wind speed of the circulation fan 41 and the power of the temperature control device 42 according to the magnitude of the difference.

[0081] The soil-crop emission greenhouse gas collection system and collection method of the present invention can be applied to the collection and measurement of carbon dioxide gas emitted from the ridge-cropped black soil-crop. Among them, the planted crop is corn, the collection time period is from June to September, when collecting gas, the total gas collection time is 30 min, and the time interval between adjacent two gas collection operations is 10 min; the specific gas collection time and measurement data are shown in Table 1 below. Figures 10 to 13 It is a curve graph of the change of carbon dioxide concentration with the gas collection time corresponding to the data in Table 1.

[0082] Table 1 Collection and measurement data of carbon dioxide emissions from ridge-cropped black soil-corn

[0083]

[0084] In Table 1, the treatment operations from the first planting to the fourth planting are to collect and measure the gas in the first gas chamber of the first gas collection box 1; the treatment operations from the first non-planting to the fourth non-planting are to collect and measure the gas in the second gas chamber of the second gas collection box 2. Figures 9 to 12 Among them, the curve graph of planting corresponds to the data of collecting and measuring the gas in the first gas chamber of the first gas collection box 1, and the curve graph of non-planting corresponds to the data of collecting and measuring the gas in the second gas chamber of the second gas collection box 2; R 2 is the correlation coefficient. When performing curve fitting according to the test data, the degree of coincidence between the test data and the fitting function is evaluated by a quantity R related to the correlation coefficient. 2 to evaluate, R 2The closer the value is to 1, the higher the degree of coincidence; the closer it is to 0, the lower the degree of coincidence. Figures 9 to 12 In 2 , R1 2 represents the correlation coefficient of the curve of planting, and R2

[0085] In the present invention, specific examples are used to illustrate the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A soil-crop greenhouse gas collection system, characterized in that: It includes a first gas collection box, a second gas collection box and a gas collection assembly; The first gas collection box includes a first base, a first box cover and a hollow cabin body, the first base is opened at both ends in the vertical direction, the lower part of the first base is used to be pre-buried in the soil, the hollow cabin body is nested inside the first base, the hollow cabin body has a lower cavity penetrating in the vertical direction, the first box cover has an upper cavity penetrating in the vertical direction, the upper cavity is correspondingly connected to the lower cavity to form a channel for the growth of crop plants; The bottom end of the first box cover is used to be sealed and connected to the top end of the first base and the top end of the hollow cabin body, and the first box cover, the first base and the hollow cabin body together form a first gas cavity; The second gas collection box has a second gas cavity; the gas collection components are respectively arranged on the outer sides of the first gas collection box and the second gas collection box, and the gas collection components are used to collect the gas in the corresponding first gas cavity and the second gas cavity.

2. The acquisition system according to claim 1, characterized in that: The first box cover comprises two split box covers, and the upper cavity is surrounded by the opposite ends of the two split box covers; A first annular groove is provided at the top of the first base and the top of the hollow cabin body, and the first annular groove extends and closes along the top edge of the first base and the top edge of the hollow cabin body; the bottom end of the split case cover is inserted into the first annular groove, and the first annular groove can water-seal the joint between the split case cover and the first base and the hollow cabin body; and / or The second gas collection box includes a second base and a second box cover, both ends of the second base in the vertical direction are opened, the lower part of the second base is used to be pre-buried in the soil, and the second box cover and the second base are surrounded to form the second gas cavity; A second annular groove is provided at the top end of the second base, and the bottom end of the second box cover is inserted into the second annular groove. The second annular groove extends and closes along the top edge of the second base, and the second annular groove can water-seal the joint between the second base and the split box cover.

3. The acquisition system according to claim 1, characterized in that: The gas collection assembly includes a gas extraction device, a gas collection device and a three-way valve; one end of the three-way valve is connected to the corresponding first gas collection box or the second gas collection box, and the other two ends are connected to the gas extraction device and the gas collection device respectively; When the three-way valve is in the first working state, the gas extraction device is connected to the corresponding first gas collection box or the second gas collection box, and is used to extract gas from the first gas cavity or the second gas cavity; when the three-way valve is in the second working state, the gas extraction device is connected to the gas collecting device, and is used to transport the extracted gas to the gas collecting device.

4. The acquisition system according to claim 1, characterized in that: The gas collection component includes an air bag, a driving component and an air collection pipeline, and the driving component is used to control the air bag to expand and inhale or contract and exhaust; Before gas collection, the airbag is in an expanded state, and the airbag is connected to the corresponding first gas collection box or the second gas collection box; When collecting gas, the air bag can also be connected to the gas collecting pipeline to transport the gas to the gas collecting pipeline.

5. The acquisition system according to claim 1, characterized in that: It also includes a temperature regulating circuit, and the outer sides of the first gas collection box and the second gas collection box are respectively connected and provided with the temperature regulating circuit; A circulation fan and a temperature control device are provided in the temperature regulating loop. The circulation fan is used to circulate the gas in the first gas cavity or the second gas cavity, and the temperature control device is used to regulate the temperature of the circulating gas.

6. The acquisition system according to claim 1, characterized in that: The hollow cabin body comprises a plurality of outer vertical plates, a plurality of inner vertical plates, a first elastic connection part and a second elastic connection part, the side ends of the plurality of outer vertical plates are sequentially fixedly connected to form an outer shell of the hollow cabin body, the side ends of the plurality of inner vertical plates are sequentially connected to form an inner shell of the hollow cabin body, and the interior of the inner shell is the lower cavity; The outer shell and the inner shell are connected via the first elastic connection portion, and the side ends of two adjacent inner vertical plates are connected via the second elastic connection portion, so that the size of the lower cavity can be adaptively adjusted.

7. The acquisition system according to claim 4, characterized in that: The driving assembly comprises a driving part, a supporting rod, an annular sleeve and an umbrella-shaped supporting structure; The annular sleeve is sleeved outside the support rod, the driving part is used to drive the annular sleeve to slide along the length direction of the support rod, the umbrella-shaped support structure is hinged to the annular sleeve and the support rod respectively, and the umbrella-shaped support structure abuts against the inner wall of the airbag; The annular sleeve can drive the umbrella-shaped support structure to open or contract. When the umbrella-shaped support structure is in an open state, the airbag is correspondingly in an expanded state; when the umbrella-shaped support structure is in a contracted state, the airbag is in a contracted state under the action of its own elasticity.

8. A method for collecting greenhouse gas emissions from soil and crops, characterized in that: The following steps are involved: Step S1: burying the lower part of the first base of the first gas collection box in the soil, planting crops in the soil in the hollow cabin in the first base, and burying the lower part of the second base of the second gas collection box in the soil; Step S2: before gas collection, the bottom end of the first box cover is sealed to the top end of the first base and the top end of the hollow cabin, and the bottom end of the second box cover is sealed to the top end of the second base; Step S3: After reaching the set gas collection time, the gas in the first gas chamber of the first gas collection box is collected by using the gas collection component to obtain a first flux of greenhouse gas emissions from soil and crops, and the gas in the second gas chamber of the second gas collection box is collected by using the gas collection component to obtain a second flux of greenhouse gas emissions from soil, and the flux of greenhouse gas emissions from crops is obtained based on the first flux and the second flux.

9. The collection method according to claim 8, characterized in that: The gas collection component includes an air bag, a driving component and a gas collection pipeline. Before gas collection, the air bag is in an expanded state, and the driving component is used to control the air bag to expand and inhale or contract and exhaust; In step S3, the step of collecting the gas in the first gas cavity or the second gas cavity by using the gas collecting component includes: After the set gas collection time is reached, the driving component controls the airbag to contract for the first time, so as to discharge the gas in the airbag into the corresponding first gas cavity or the second gas cavity for mixing; The driving component controls the airbag to expand and inhale the mixed gas; The airbag is connected to the gas collecting pipeline, and the driving component controls the airbag to contract for the second time to deliver the mixed gas to the gas collecting pipeline.

10. The collection method according to claim 8, characterized in that: The outer sides of the first gas collection box and the second gas collection box are respectively provided with a temperature regulating circuit, and the temperature regulating circuit is provided with a circulation fan and a temperature control device; The method further comprises: Acquire a first temperature value inside the first gas collection box or the second gas collection box, and acquire a second temperature value outside, to obtain a difference between the first temperature value and the second temperature value; The wind speed of the circulation fan and the power of the temperature control device are controlled according to the size of the difference.

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