A method and device for measuring carbon sequestration and emission reduction in soil

Abstract

The application relates to a kind of soil carbon fixation and emission reduction field determination method and device, method includes to the organic carbon detection of sampling hole, microorganism activity detection, bulk density detection and temperature and humidity detection, and the concentration change of carbon dioxide and methane in sampling hole is monitored, to determine carbon dioxide and methane emission flux;Then the emission flux is corrected once using the microorganism activity detection result;According to the total amount of soil carbon storage of organic carbon detection result, bulk density detection and temperature and humidity detection, the emission flux of primary correction is corrected twice using the total amount of soil carbon storage, finally, based on the emission flux of secondary correction, determine carbon fixation amount, and determine emission reduction potential index in combination with emission amount.The present application can not only improve detection efficiency and precision, but also simple structure, easy to operate.

Description

Technical Field

[0001] This invention relates to the field of soil testing technology, and more specifically to a field measurement method and apparatus for soil carbon sequestration and emission reduction. Background Technology

[0002] With the increasing severity of global climate change, soil carbon sequestration and emission reduction are of great significance for mitigating the greenhouse effect. Accurately measuring the carbon sequestration and emission reduction of field soils is crucial for assessing soil ecosystem functions and developing agricultural strategies to address climate change.

[0003] However, existing soil carbon sequestration and emission reduction measurement devices have many shortcomings.

[0004] For example, some devices have complex structures and are difficult to operate, making them inconvenient for rapid field measurements; some devices have limited measurement accuracy and cannot accurately reflect the true situation of soil carbon sequestration and emission reduction; and some devices cannot simultaneously measure multiple factors affecting soil carbon sequestration and emission reduction, resulting in incomplete measurement results.

[0005] Therefore, there is an urgent need to develop a field measurement device for soil carbon sequestration and emission reduction that is easy to operate, has high measurement accuracy, and can comprehensively measure multiple related factors. Summary of the Invention

[0006] In view of this, in order to at least partially solve the above-mentioned technical problems, the present invention provides a method and apparatus for field measurement of soil carbon sequestration and emission reduction; to achieve the above objectives, the present invention adopts the following technical solution:

[0007] On the one hand, this application provides a field measurement method for soil carbon sequestration and emission reduction, including:

[0008] Organic carbon, microbial activity, bulk density, and temperature and humidity were measured at the sampling wells.

[0009] Collect gas from the sampling orifice and monitor changes in the concentrations of carbon dioxide and methane in the gas;

[0010] The emission fluxes of carbon dioxide and methane are determined based on concentration changes, and the emission fluxes are corrected once using the results of microbial activity detection.

[0011] The total soil carbon storage is determined based on organic carbon detection results, bulk density detection, and temperature and humidity detection. The total soil carbon storage is then used to make a secondary correction to the emission flux of the first correction.

[0012] Carbon sequestration is determined based on the second-corrected emission flux, and the emission reduction potential index is determined in conjunction with the emission volume.

[0013] As a preferred option, the emission flux is determined using the following formula:

[0014]

[0015] In the formula, C represents the concentration of carbon dioxide or methane in the gas, dC / dt represents the rate of change of concentration, V represents the volume of the collection box, A represents the contact area between the collection box and the soil, M represents the molar mass of the gas, R represents a constant, and T represents the temperature.

[0016] Preferably, the emission flux is corrected using the results of microbial activity detection, including:

[0017]

[0018] In the formula, F raw Indicates emission flux, ATP base Indicating reference microbial activity, ATP current This represents the current microbial activity detection value, and the index β represents the nonlinear effect of microbial activity on respiration, preferably 0.5.

[0019] Preferably, the total soil carbon storage is determined based on organic carbon testing results, bulk density testing, and temperature and humidity testing, including:

[0020]

[0021] In the formula, C stock SOC represents total carbon storage. i ρ represents the organic carbon content of the i-th soil layer. i d represents the bulk density of the i-th soil layer. i θ represents the depth of the i-th layer. i This represents the volumetric water content of the i-th layer.

[0022] As a preferred option, the total soil carbon storage is used to perform a secondary correction on the emission fluxes from the primary correction; including:

[0023]

[0024] In the formula, F adj This represents the first-order corrected emission flux, where 'a' is the empirical attenuation coefficient, preferably between 0.05 and 0.1, and C... inert This indicates the amount of inert carbon at the bottom layer, which can be obtained directly through organic carbon.

[0025] Preferably, carbon sequestration is determined based on the emission flux after secondary correction, including:

[0026]

[0027] In the formula, C loss This indicates the amount of carbon loss, and t1 and t2 represent the monitoring time intervals. This represents the secondary correction flux for carbon dioxide emissions. This represents the secondary corrected emission flux of methane;

[0028] In this embodiment, CH4 is converted to carbon equivalent according to GWP-100 (1 kg CH4 is approximately 25 kg CO2-eq).

[0029] C net =C input -C loss

[0030] In the formula, C net Indicates carbon sequestration, C input This indicates the amount of carbon input.

[0031] As a preferred approach, an emission reduction potential index is determined by combining emissions levels, including:

[0032]

[0033] In the formula, C net Indicates carbon sequestration, C net.max F represents the region's or history's maximum net carbon sequestration. baseline F represents the baseline flux. current This represents the flux value after the second correction; and

[0034]

[0035] As a preferred option, the baseline flux F baseline Determined based on historical data or regional default values, or derived as follows:

[0036]

[0037] In the formula, k is the regional carbon loss coefficient, D is the sampling hole depth, and C stock Let T be the total carbon storage, and f(T,θ) be the temperature and humidity control function.

[0038] Secondly, this application provides a field measurement device for soil carbon sequestration and emission reduction, employing any of the soil carbon sequestration and emission reduction field methods described above, including a sampling probe and a gas collection box connected thereto, as well as a gas analyzer and a detection host, wherein...

[0039] The sampling probe is used to sample the gas in the sampling hole and deliver the sampled gas to the gas collection box; it also performs stratified organic carbon detection, microbial activity detection, bulk density detection, and temperature and humidity detection on the sampling hole and transmits the detection results to the detection host.

[0040] Gas collection boxes are used to collect gases;

[0041] The gas analyzer, connected to the gas collection box, is used to monitor changes in the concentration of carbon dioxide and methane in the gas and transmits the monitoring results to the detection host.

[0042] The detection host is used to determine the emission flux of carbon dioxide and methane based on concentration changes, and to make a first correction to the emission flux using the results of microbial activity detection; to determine the total soil carbon storage based on the results of organic carbon detection, bulk density detection, and temperature and humidity detection, and to make a second correction to the emission flux based on the total soil carbon storage; and to determine the carbon sequestration based on the emission flux after the second correction, and to determine the emission reduction potential index in combination with the emission volume.

[0043] Preferably, the sampling probe features a telescopic sleeve structure on its outer side, with each sleeve's outer wall circumferentially embedded with an organic carbon detection sensor, a soil microbial activity detection sensor, a soil bulk density detection sensor, and a soil temperature and humidity detection sensor. This probe can complete in-situ layered detection of soil at different depths in a single operation. Compared to traditional layer-by-layer drilling sampling, this method improves operational efficiency by over 50%, avoids soil structure damage caused by multiple samplings, and provides stronger spatial consistency of the data.

[0044] A polyurethane telescopic tube is installed on the inner side. The telescopic tube extends and retracts with the sleeve and samples are taken through the sampling port at the bottom of the sleeve, thereby effectively isolating external gas interference and ensuring the representativeness of the gas sample.

[0045] This invention discloses a field measurement method and apparatus for soil carbon sequestration and emission reduction, which has the following advantages compared with the prior art:

[0046] 1. Multiple factors affecting soil carbon sequestration and emission reduction were considered, including organic carbon content, microbial activity, soil bulk density, and temperature and humidity, making the measurement results more comprehensive and objective; at the same time, stratified sampling effectively improved sampling efficiency.

[0047] 2. For the first time, microbial activity was introduced as a dynamic correction factor into flux calculation, breaking through the limitation of traditional models that rely solely on environmental parameters; through secondary correction of total soil carbon storage, the accurate calculation of carbon sequestration and emission reduction was further ensured.

[0048] 3. The carbon sequestration amount was determined based on the emission flux after secondary correction, and the emission reduction potential index was calculated in combination with the emission amount, which improved the measurement accuracy and provided a scientific basis for assessing the emission reduction capacity of soil ecosystems and setting emission reduction targets.

[0049] 4. By integrating multiple types of sensors through a retractable quadruped sampling probe, combined with the dynamic sealing technology of the gas collection box and intelligent early warning algorithms, multi-dimensional real-time monitoring of soil carbon sequestration and emission reduction can be achieved. The device features high precision, scalability, and automated early warning functions, making it suitable for agricultural ecological research and carbon sink management. It requires no complex equipment assembly or debugging, allowing researchers and farmers to use it quickly and conveniently in actual field environments. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0051] Figure 1 Flowchart of the field measurement method for soil carbon sequestration and emission reduction provided by the present invention;

[0052] Figure 2 A schematic diagram of the field measurement device for soil carbon sequestration and emission reduction provided by the present invention;

[0053] Figure 3 This is a cross-sectional view of the sampling probe structure provided by the present invention;

[0054] Figure 4 This is a front view of the sampling probe structure provided by the present invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0056] Example 1

[0057] This invention discloses a field measurement method for soil carbon sequestration and emission reduction, referring to... Figure 1 The steps include:

[0058] S1. Perform stratified organic carbon detection, microbial activity detection, bulk density detection, and temperature and humidity detection on the sampling wells to assess the current carbon pool size and vertical distribution characteristics of the soil, while also taking into account multiple factors that affect soil carbon sequestration and emission reduction.

[0059] S2. Collect the gas from the sampling hole and monitor the changes in the concentrations of carbon dioxide and methane in the gas;

[0060] Because CO2 molecules have a strong absorption characteristic of infrared light in a specific infrared band (around 4.26 μm), the CO2 concentration can be calculated by emitting broad-spectrum infrared light through a gas sample using an NDIR sensor, detecting the attenuation of the transmitted light intensity, and then applying the Lambert-Beer Law.

[0061] For methane, tunable diode laser absorption light technology is used for detection.

[0062] S3. Determine the emission fluxes of carbon dioxide and methane based on concentration changes, and make a correction to the emission fluxes using the results of microbial activity detection;

[0063] In one embodiment, after the gas collection box is sealed, the change in gas concentration inside the box over time is continuously monitored (e.g., recorded every 10 seconds); then a concentration-time curve is fitted, typically showing linear or non-linear growth (e.g., CO2 emission flux); finally, the emission flux is determined using the following formula:

[0064]

[0065] In the formula, C represents the concentration of carbon dioxide or methane in the gas, dC / dt represents the rate of change of concentration, V represents the volume of the collection box, A represents the contact area between the collection box and the soil, M represents the molar mass of the gas, R represents a constant, and T represents the temperature.

[0066] Then, the emission flux is corrected using the results of microbial activity testing, including:

[0067]

[0068] In the formula, F raw Indicates emission flux, ATP base Indicating reference microbial activity, ATP current This represents the current microbial activity detection value, and the index β represents the nonlinear effect of microbial activity on respiration, preferably 0.5.

[0069] This application is the first to introduce microbial activity as a dynamic correction factor into flux calculation, breaking through the limitation of traditional models that rely solely on environmental parameters.

[0070] S4. Based on organic carbon detection results, bulk density detection, and temperature and humidity detection, the total soil carbon storage is determined. This total soil carbon storage is then used to perform a secondary correction on the emission flux from the initial correction. This secondary correction integrates the spatial distribution, physical structure, and moisture status of carbon storage, combining short-term microbial respiration signals with long-term carbon stability. This achieves a leap from "instantaneous flux monitoring" to "net carbon sequestration potential assessment," providing core quantitative decision-making parameters for climate-smart agriculture. Specifically,

[0071] In this embodiment, the total soil carbon storage is determined based on organic carbon detection results, bulk density detection, and temperature and humidity detection, including:

[0072]

[0073] In the formula, C stock SOC represents total carbon storage. i ρ represents the organic carbon content of the i-th soil layer. id represents the bulk density of the i-th soil layer. i θ represents the depth of the i-th layer. i This represents the volumetric water content of the i-th layer.

[0074] Secondary corrections are made to the emission fluxes from the primary correction using total soil carbon storage; including:

[0075]

[0076] In the formula, F adj This represents the first-order corrected emission flux, where 'a' is the empirical attenuation coefficient, preferably between 0.05 and 0.1, and C... inert This indicates the amount of inert carbon at the bottom layer, which can be obtained directly through organic carbon.

[0077] S5. Determine the carbon sequestration amount based on the second-corrected emission flux, and combine it with the emission amount to determine the emission reduction potential index.

[0078] Carbon sequestration was determined based on the second-corrected emission flux, including:

[0079]

[0080] In the formula, C loss This indicates the amount of carbon loss, and t1 and t2 represent the monitoring time intervals. This represents the secondary correction flux for carbon dioxide emissions. This represents the secondary corrected emission flux of methane;

[0081] In this embodiment, CH4 is converted to carbon equivalent according to GWP-100 (1 kg CH4 is approximately 25 kg CO2-eq).

[0082] C net =C input -C loss

[0083] In the formula, C net Indicates carbon sequestration, reflecting the net change in the soil carbon pool, C input The amount of carbon input can be directly measured: by determining litter volume, root biomass, etc. through field trials, and then estimating it in combination with carbon content (usually 40-50%); or by estimating it through models: if measured data is lacking, it can be estimated using empirical models based on crop yield and management practices (such as the proportion of straw returned to the field).

[0084] The formula for calculating the emission reduction potential index is:

[0085]

[0086] In the formula, C net Indicates carbon sequestration, C net.maxThis represents the region's or history's maximum net carbon sequestration, which can be determined through model simulation or long-term observation. F current This represents the flux value after the second correction; and

[0087]

[0088] F baseline This indicates that the baseline flux is determined based on historical data or regional default values. When historical flux data is lacking, it can be derived as follows:

[0089]

[0090] In the formula, k is the regional carbon loss coefficient, D is the sampling hole depth, and C stock Let T be the total carbon storage, and f(T,θ) be the temperature and humidity control function.

[0091] This application employs a two-stage dynamic correction for emission fluxes, specifically including:

[0092] Nonlinear correction for microbial activity: For the first time, a microbial activity index (α = 0.5) is introduced to correct the nonlinearity of emission flux. Based on the Logistic growth characteristics of microbial respiration, the flux calculation error is reduced from ±15% in the traditional linear model to ±5%.

[0093] Carbon storage decay compensation mechanism: By comparing the total carbon storage with the inert carbon baseline value, the flux value is dynamically adjusted using an empirical decay coefficient (β = 0.05-0.1), which effectively distinguishes the contributions of the active carbon pool and the stable carbon pool, thus improving the accuracy of long-term carbon sequestration prediction by 20%.

[0094] Example 2

[0095] This application provides a field measurement device for soil carbon sequestration and emission reduction, such as... Figure 2 As shown, it includes a sampling probe and a gas collection box connected to it, as well as a gas analyzer and a detection host, wherein,

[0096] The sampling probe is used to sample the gas in the sampling hole and deliver the sampled gas to the gas collection box; it also performs stratified organic carbon detection, microbial activity detection, bulk density detection, and temperature and humidity detection on the sampling hole and transmits the detection results to the detection host.

[0097] The gas collection box is used to collect gas; in this embodiment, the gas collection box 2 is in the shape of an inverted funnel, such as... Figure 3 and Figure 4 The bottom is equipped with a ring-shaped airbag 3, which can form a sealed space when inflated to improve the purity of the collected gas.

[0098] A gas analyzer is connected to a gas collection tank through Valve 1 and is used to monitor the changes in the concentrations of carbon dioxide and methane in the gas and transmit the monitoring results to a detection host computer.

[0099] The detection host computer is used to determine the carbon dioxide and methane emission fluxes based on the concentration changes, and perform a primary correction on the emission fluxes using the results of the microbial activity detection; determine the total soil carbon storage based on the results of the organic carbon detection, the bulk density detection, and the temperature and humidity detection, and perform a secondary correction on the emission fluxes that have been primarily corrected using the total soil carbon storage; and determine the carbon sequestration amount based on the emission fluxes after the secondary correction, and determine the emission reduction potential index in combination with the emissions.

[0100] As a preferred implementation, an intelligent warning unit is provided in the detection host computer, which is used to support the abnormal identification and hierarchical warning of soil carbon sequestration and emission reduction based on a threshold algorithm dynamically corrected by historical data, such as acoustic and optical alarms and mobile terminal push notifications.

[0101] In one embodiment, the classification rules are as follows:

[0102] ERI > 30%: High emission reduction potential (green), it is recommended to maintain management;

[0103] 10% < ERI < 30%: Medium potential (yellow), it is recommended to optimize fertilization;

[0104] ERI < 10%: Low potential (red), systematic improvement is required. [[ID=二十]]

[0105] [[ID=二十一]]During operation, first, according to the required sampling depth, the detection host computer controls the probe positioning, and the gas collection tank contacts the ground. At this time, the airbag is inflated to complete the sealing; then, the gas pump extracts the sample to the collection tank; when the required gas pressure is reached, Valve 1 is opened and then analyzed by the gas analyzer, and then uploaded to the detection host computer. [[ID=二十二]] [[ID=二十三]]

[0106] [[ID=二十四]]To further optimize the above technical solution, such as [[ID=二十五]] Figure 3 [[ID=二十六]], the outer side of the sampling probe is a telescopic sleeve structure 4, which can adopt a segmented thread locking structure and can independently adjust the insertion depth (10 - 100 cm). In a preferred solution, a spiral破土锥头 7 is provided at the end; [[ID=二十七]] [[ID=二十八]]

[0107] [[ID=二十九]]The outer wall surface of each stage of the sleeve of the rod body is coated with an anti-corrosion coating, and an organic carbon detection sensor, a soil microbial activity detection sensor, a soil bulk density detection sensor, and a soil temperature and humidity detection sensor are embedded circumferentially; a polyurethane expansion tube 5 is arranged inside, and the expansion tube expands and contracts with the sleeve, and sampling is performed through the sampling air port 6 at the bottom of the sleeve. [[ID=三十]] [[ID=三十一]]

[0108] [[ID=三十二]]Preferably, to solve the stability problem of the traditional single-rod structure, the probe of this application is designed as a four-foot probe. [[ID=三十三]] [[ID=三十四]]

[0109] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0110] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A field method for measuring soil carbon sequestration and emission reduction, characterized in that, include: Organic carbon, microbial activity, bulk density, and temperature and humidity were measured at the sampling wells. Collect gas from the sampling orifice and monitor changes in the concentrations of carbon dioxide and methane in the gas; The emission fluxes of carbon dioxide and methane are determined based on concentration changes, and the emission fluxes are corrected once using the results of microbial activity detection. include: In the formula, F raw Indicates emission flux, ATP base Indicating reference microbial activity, ATP current This represents the current detected value of microbial activity, and the index β represents the nonlinear effect of microbial activity on respiration. The total soil carbon storage is determined based on organic carbon detection results, bulk density detection, and temperature and humidity detection. This total soil carbon storage is then used to perform a secondary correction on the emission fluxes from the initial correction. This includes: In the formula, F adj This represents the first-order corrected emission flux, where 'a' is the empirical attenuation coefficient, and C... inert Indicates the amount of inert carbon stored at the bottom layer, C stock Indicates total carbon storage; Carbon sequestration is determined based on the second-corrected emission flux, and an emission reduction potential index is determined in conjunction with the emission volume; including: In the formula, C net Indicates carbon sequestration, C net.max F represents the region's or history's maximum net carbon sequestration. baseline F represents the baseline flux. current This represents the flux value after the second correction; and F represents the secondary correction flux of carbon dioxide emissions. CH4,final This represents the secondary correction flux of methane emissions.

2. The field measurement method for soil carbon sequestration and emission reduction according to claim 1, characterized in that, Emission flux is determined by the following formula: In the formula, C represents the concentration of carbon dioxide or methane in the gas, dC / dt represents the rate of change of concentration, V represents the volume of the collection box, A represents the contact area between the collection box and the soil, M represents the molar mass of the gas, R represents a constant, and T represents the temperature.

3. The field measurement method for soil carbon sequestration and emission reduction according to claim 1, characterized in that, The total soil carbon storage was determined based on organic carbon testing results, bulk density testing, and temperature and humidity testing, including: In the formula, C stock SOC represents total carbon storage. i ρ represents the organic carbon content of the i-th soil layer. i d represents the bulk density of the i-th soil layer. i θ represents the depth of the i-th layer. i This represents the volumetric water content of the i-th layer.

4. The field measurement method for soil carbon sequestration and emission reduction according to claim 1, characterized in that, Carbon sequestration was determined based on the second-corrected emission flux, including: In the formula, C loss t1 and t2 represent the carbon loss amount, and t1 and t2 represent the monitoring time intervals; C net =C input -C loss In the formula, C net Indicates carbon sequestration, C input This indicates the amount of carbon input.

5. The field measurement method for soil carbon sequestration and emission reduction according to claim 1, characterized in that, Reference flux F baseline Determined based on historical data or regional default values, or derived as follows: In the formula, k is the regional carbon loss coefficient, D is the sampling hole depth, and C stock Let T be the total carbon storage, and f(T,θ) be the temperature and humidity control function.

6. A field measurement device for soil carbon sequestration and emission reduction, characterized in that, The field method for soil carbon sequestration and emission reduction according to any one of claims 1-5 includes a sampling probe and a gas collection box connected thereto, as well as a gas analyzer and a detection host, wherein... The sampling probe is used to sample the gas in the sampling hole and deliver the sampled gas to the gas collection box; it also performs stratified organic carbon detection, microbial activity detection, bulk density detection, and temperature and humidity detection on the sampling hole and transmits the detection results to the detection host. Gas collection boxes are used to collect gases; The gas analyzer, connected to the gas collection box, is used to monitor changes in the concentration of carbon dioxide and methane in the gas and transmits the monitoring results to the detection host. The detection host is used to determine the emission flux of carbon dioxide and methane based on concentration changes, and to make a first correction to the emission flux using the results of microbial activity detection; to determine the total soil carbon storage based on the results of organic carbon detection, bulk density detection, and temperature and humidity detection, and to make a second correction to the emission flux based on the total soil carbon storage; and to determine the carbon sequestration based on the emission flux after the second correction, and to determine the emission reduction potential index in combination with the emission volume.

7. The field measurement device for soil carbon sequestration and emission reduction according to claim 6, characterized in that, The outer side of the sampling probe is a telescopic sleeve structure. Each sleeve has an organic carbon detection sensor, a soil microbial activity detection sensor, a soil bulk density detection sensor, and a soil temperature and humidity detection sensor embedded in its outer wall. A polyurethane telescopic tube is installed on the inner side. The telescopic tube extends and retracts with the sleeve and samples are taken through the sampling port at the bottom of the sleeve.

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