Method and system for estimating organic carbon reserve change of soil in vegetable field in short time

Abstract

The invention provides a method and a system for estimating organic carbon reserve change of soil in a vegetable field in a short time, and belongs to the technical field of soil measurement. The method comprises the following steps: acquiring net ecosystem carbon income and expenditure (NECB); and estimating the organic carbon reserve of the vegetable field soil by using net ecosystem carbon income and expenditure (NECB). According to the method, the organic carbon reserve of the soil in the vegetable field can be quickly estimated, the influence of different farming measures on the organic carbon reserve of the soil in the vegetable field in a short period can be known, and farmers and agricultural managers can optimize management measures such as fertilization, irrigation and planting modes; carbon emission and fixed conditions of a farmland ecosystem can be determined, so that the speed and the degree of climate change can be better predicted, and reasonable vegetable planting management measures can be taken in time.

Description

Technical Field

[0001] The present invention relates to the technical field of quantitative soil science, and in particular to a method and system for estimating changes in soil organic carbon reserves in a vegetable field in a short period of time. Background Art

[0002] Carbon sink refers to the process, activity or mechanism of absorbing and fixing atmospheric carbon dioxide in vegetation, soil, ocean or other storage media through natural or human activities. The formation of carbon sink reduces the concentration of carbon dioxide in the atmosphere, thus helping to mitigate the greenhouse effect and global warming. As one of the three major terrestrial systems, farmland ecosystem accounts for 38.5% of terrestrial ecosystems and is the most active carbon pool in the carbon cycle. Its carbon sink and carbon fixation capacity are often underestimated or even ignored in previous studies. Some scholars have pointed out that farmland, woodland and grassland can absorb more carbon dioxide after fertilization, irrigation and other management measures than farmland, woodland and grassland without management measures, and have great potential for increasing carbon sinks. However, since the stability and duration of soil carbon sinks fixing organic carbon in the soil are still controversial, and different research areas, farmland planting structures, farmland management measures, etc. will affect farmland soil carbon sinks, the uncertainty of farmland soil carbon sink estimation is relatively high.

[0003] Among all types of farmland, vegetable fields have unique ecological characteristics. Vegetable field soil organic carbon is affected by both human activities and short planting cycles. Its stability is poor and it is easily affected by changes in the external environment and fluctuates. Vegetable growth cycles are generally short, and planting crops are frequent, which makes the soil organic carbon turnover rate faster. In the frequent planting and harvesting process, the input and output activities of organic carbon are very frequent. At present, the estimation method for the change of vegetable field soil organic carbon storage is not perfect enough, and there is a lack of a fast and accurate method to estimate the change of vegetable field soil organic carbon storage. This has, to a certain extent, limited the in-depth research and rational utilization of the carbon sink function of vegetable field soil.

[0004] Therefore, developing a method that can quickly estimate changes in soil organic carbon stocks in vegetable fields is of great practical significance. Summary of the invention

[0005] In order to overcome the problems existing in the related art, one of the purposes of the present invention is to provide a method for estimating the changes in soil organic carbon reserves in vegetable fields in the short term. The method can quickly estimate the soil organic carbon reserves in vegetable fields, help understand the effects of different fertilizer amounts and types on soil organic carbon reserves, and help farmers and agricultural managers optimize management measures such as fertilization, irrigation and planting patterns; it can also help understand the ability of ecosystems to absorb or release carbon dioxide, thereby better predicting the speed and extent of climate change and taking reasonable land management measures in a timely manner.

[0006] A method for estimating soil organic carbon stock changes in vegetable fields over the short term;

[0007] Obtain the net ecosystem carbon budget NECB;

[0008] The net ecosystem carbon budget (NECB) was used to estimate the soil organic carbon storage in vegetable fields, where the calculation formula is as follows:

[0009] δSOC=0.07×NECB.

[0010] In a preferred technical solution of the present invention, the step of obtaining the net ecosystem carbon budget NECB comprises:

[0011] Calculate gross primary productivity GPP;

[0012] Determination of ecosystem CO 2 Cumulative emissions Re, where Re refers to the ecosystem CO measured by the static dark box method 2 Cumulative emissions;

[0013] Determine the amount of carbon H taken away by vegetable production;

[0014] Determination of cumulative methane emissions from vegetable fields 4 , where CH 4 Refers to the ecosystem CO measured by the static dark box method 2 Cumulative emissions;

[0015] Calculate the amount of carbon M brought into the field by applying organic fertilizer;

[0016] Calculate the net ecosystem carbon budget NECB;

[0017] GPP, Re, H, CH 4 Substitute M into the formula:

[0018] NECB=GPP-Re-H-CH 4 +M;

[0019] Calculate the value of NECB.

[0020] In a preferred technical solution of the present invention, the calculation of the gross primary productivity GPP comprises:

[0021] Obtain the net primary productivity NPP and calculate the gross primary productivity GPP using the formula GPP = NPP ÷ 0.6;

[0022] Where NPP = NPP harvest +NP Presidue +NPP exudate ;

[0023] NPP harvestRefers to the sum of the carbon content of the harvested parts of vegetable crops, determined by the potassium dichromate volumetric method;

[0024] NPP residue Refers to the carbon content of the aboveground part of vegetables after harvest; it is estimated by measuring the carbon content of the remaining part of the unharvested vegetables in a set area;

[0025] NPP exudate It refers to the sum of the carbon content of root exudates, which is estimated as 10% of the total biological carbon content.

[0026] In a preferred technical solution of the present invention, the determination of ecosystem CO 2 Cumulative emissions Re, including:

[0027] Collect gas samples using a collection device and record environmental factors when collecting the gas samples;

[0028] The collected gas samples are tested to obtain CO 2 Concentration data;

[0029] According to CO 2 Concentration data, combined with environmental factors when the gas samples were collected, can be used to determine the ecosystem CO 2 Cumulative emissions Re.

[0030] In a preferred technical solution of the present invention, the method for determining the cumulative methane emissions from vegetable fields CH 4 ,include:

[0031] Collect gas samples using a collection device and record environmental factors when collecting the gas samples;

[0032] The collected gas samples are tested to obtain CH 4 Concentration data;

[0033] According to CH 4 The concentration data, combined with the environmental factors when the gas samples were collected, were used to determine the cumulative methane emissions from the vegetable fields. 4 .

[0034] In a preferred technical solution of the present invention, the greenhouse gas emission flux F is calculated using the following formula:

[0035]

[0036] Where F is CO 2 or CH 4 Emission flux, unit is mg·(m 2 h) -1 ; ρ is CO under standard conditions 2 or CH 4Density, in kg·m -3 ; V is the volume of the collection device, in m 3 ; A is the soil surface area in the base of the collection device, in m 2 ; Δc / Δt is the rate of change of gas concentration in the box when collecting gas; T is the average temperature in the box when collecting gas, in ℃.

[0037] In a preferred technical solution of the present invention, the step of determining the amount of carbon H taken away by vegetable production includes:

[0038] Determine vegetable yields;

[0039] Convert vegetable yields to dry weight;

[0040] Match the carbon content of the corresponding vegetables according to their dry weight;

[0041] Based on the dry weight of vegetables and the carbon content of the corresponding vegetables, calculate the amount of carbon H taken away by vegetable production.

[0042] In a preferred technical solution of the present invention, the calculation of the amount of carbon M brought into the field by the application of organic fertilizer includes:

[0043] Get the weight m of organic fertilizer applied per unit area of ​​vegetable field, where the unit of m is kg·m -2

[0044] Determine the organic matter content ω of the applied organic fertilizer, the unit of ω is g·kg -1 ;

[0045] The formula M = m × ω × 0.58 is used to calculate the amount of carbon M brought into the field by the application of organic fertilizer. The unit of M is g·m -2 .

[0046] A second object of the present invention is to provide a system for estimating changes in soil organic carbon reserves in a vegetable field, which is used to implement the method for estimating changes in soil organic carbon reserves in a vegetable field in a short period of time as described above.

[0047] The beneficial effects of the present invention are:

[0048] The present invention provides a method for estimating the change of soil organic carbon storage in a vegetable field in a short term, the method comprising: obtaining the net ecosystem carbon balance NECB; estimating the soil organic carbon storage in the vegetable field using the net ecosystem carbon balance NECB. Based on the results obtained by this estimation method, farmers and agricultural managers can judge the rationality of current measures such as the amount of fertilizer applied and the selection of planting varieties (such as leafy vegetable planting has a positive impact in this case); the estimation method can timely and accurately reflect the carbon balance of the vegetable field ecosystem, which is helpful for scientific researchers and ecological managers to monitor changes in the carbon balance of the ecosystem. When abnormal carbon balance is found (such as continuous decrease or even negative δSOC), timely measures can be taken, such as adjusting agricultural activities, strengthening soil protection, etc., to maintain the stability of the ecosystem.

[0049] The present application also provides a system for the method of estimating changes in soil organic carbon reserves in vegetable fields in the short term in the embodiment described above. The system can effectively estimate changes in soil organic carbon reserves, thereby providing strong data support for farmers and agricultural managers to optimize management measures such as fertilization, irrigation and planting patterns, and helping to understand the ability of ecosystems to absorb or release carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a schematic diagram of a method for estimating changes in soil organic carbon storage in a vegetable field in a short period of time provided in an embodiment of the present invention;

[0051] Figure 2 It is a schematic diagram of obtaining the net ecosystem carbon budget NECB provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0052] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0053] Among all types of farmland, vegetable fields have unique ecological characteristics. Vegetable field soil organic carbon is affected by both human activities and short planting cycles. Its stability is poor and it is easily affected by changes in the external environment and fluctuates. Vegetable growth cycles are generally short, and planting crops are frequent, which makes the soil organic carbon turnover rate faster. In the frequent planting and harvesting process, the input and output activities of organic carbon are very frequent. At present, the estimation method for the change of vegetable field soil organic carbon storage is not perfect enough, and there is a lack of a fast and accurate method to estimate the change of vegetable field soil organic carbon storage. This has, to a certain extent, limited the in-depth research and rational utilization of the carbon sink function of vegetable field soil.

[0054] Based on this, the present application provides a method for estimating changes in soil organic carbon storage in vegetable fields in the short term.

[0055] Example 1

[0056] like Figure 1-Figure 2 As shown, this embodiment provides a method for estimating the change of soil organic carbon storage in a vegetable field in a short period of time;

[0057] S100, obtain the net ecosystem carbon budget NECB;

[0058] Specifically, obtaining the net ecosystem carbon budget NECB includes:

[0059] S101. Calculate gross primary productivity (GPP);

[0060] The calculation of gross primary productivity (GPP) includes:

[0061] Obtain the net primary productivity NPP and calculate the gross primary productivity GPP using the formula GPP = NPP ÷ 0.6;

[0062] Where NPP = NPP harvest +NP Presidue +NPP exudate ; Wherein 0.6 is the reference ratio, which can be obtained according to the prior art. It should also be noted that in the vegetable field ecosystem, the amount of carbon lost as volatile organic carbon and dissolved in groundwater is very small, so this part of carbon and the carbon lost due to erosion are not considered in the total carbon loss. NECB (Net Ecosystem Carbon Balance) refers to the net difference between the carbon input and carbon output of the ecosystem (including vegetation, soil and other biological components). When NECB>0, the ecosystem behaves as a carbon sink, that is, the ecosystem absorbs more carbon than it releases. When NECB<0, the ecosystem behaves as a carbon source, that is, the ecosystem releases more carbon than it absorbs. This application can obtain the changes in organic carbon in vegetable field soil in the short term by estimating NECB in the short term. Compared with other schemes that require two or three years to measure the organic carbon in the soil, this greatly improves the efficiency of estimating organic carbon in the soil, thereby being able to better provide a basis for optimizing land management measures (such as fertilization, irrigation, planting patterns, etc.).

[0063] NPP harvest It refers to the sum of the carbon content of the harvested part of vegetable crops, which is determined using the potassium dichromate volumetric method; for example, in actual operation, after harvesting leafy vegetables, a certain amount of samples are selected and processed according to the standard process of the potassium dichromate volumetric method to obtain their carbon content.

[0064] NPP residueRefers to the carbon content of the aboveground part of vegetables after harvest; it is estimated by measuring the carbon content of the remaining part of the unharvested vegetables in a set area;

[0065] Specifically, the NPP of different vegetables residue For vegetables such as pakchoi, amaranth, spinach and cilantro that are harvested in one go, NPP residue It is the carbon content of the aboveground part of vegetables after harvest. Water spinach can be harvested multiple times, and the carbon content of its roots and the aboveground parts remaining in the soil that have not been harvested is measured by selecting 10m 2 The vegetable soil samples are estimated from the selected area, for example, 10m 2 In this area, the carbon content of the remaining parts of the water spinach was carefully separated and determined.

[0066] NPP exudate Refers to the sum of the carbon content of root secretions, which is calculated as 10% of the total biological carbon content. In actual calculations, the carbon content of each part of the vegetable that has been measured is added together to obtain the total biological carbon content, and then multiplied by 10% to obtain NPP. exudate The numerical value of .

[0067] S102. Determination of ecosystem CO 2 Cumulative emissions Re, where Re refers to the ecosystem CO measured by the static dark box method 2 Cumulative emissions;

[0068] Specifically, the determination of ecosystem CO 2 Cumulative emissions Re, including:

[0069] Collect gas samples using a collection device and record environmental factors when collecting the gas samples;

[0070] The collected gas samples are tested to obtain CO 2 Concentration data;

[0071] According to CO 2 Concentration data, combined with environmental factors when the gas samples were collected, can be used to determine the ecosystem CO 2 Cumulative emissions Re.

[0072] Specifically, the static dark chamber method was used to measure ecosystem CO 2 The cumulative emissions Re, the specific steps are as follows:

[0073] Prepare the measuring device: Use a box made of PVC material (size 40cm×40cm×50cm) and a base with grooves as a gas collection device. Install a thermometer and a gas collection port with a three-way valve on the top of the box to facilitate measuring the temperature inside the box and collecting gas. Fix the base in a suitable position in the test area to prepare for subsequent gas collection.

[0074] Determine sampling time and frequency: Intensive gas sampling is carried out on the 1st, 3rd and 7th day after fertilization to more accurately monitor CO in the short term after fertilization. 2 At other times, the sampling frequency is set to once a week to ensure continuous tracking of ecosystem CO 2 The long-term trend of emissions. The gas sampling time is fixed at 09:00-12:00 each time, because the environmental conditions are relatively stable during this period, which can reduce the measurement error caused by different time.

[0075] Collecting gas samples: When collecting gas, first fill the groove with water so that the lower edge of the box is placed in the groove to form a relatively sealed environment to avoid interference from external air and ensure that the collected gas is truly emitted by the ecosystem in the experimental plot. After covering the gas collection box, use a 100mL syringe to fully mix the gas in the box at 0 minutes, 10 minutes, and 20 minutes to ensure that the collected gas is representative. Then, extract 30mL from the mixed gas and inject it into a 12mL headspace bottle that has been evacuated to complete the collection of gas samples.

[0076] Record environmental indicators: While collecting gas samples, record environmental indicators such as temperature, air pressure, soil temperature and humidity in the chamber. These indicators are important for subsequent analysis of CO 2 The relationship between emissions and environmental factors is crucial and helps to gain a deeper understanding of ecosystem CO 2 Emission rules.

[0077] Laboratory determination of CO 2 Content: Bring the headspace bottle with the collected gas sample back to the laboratory and use an instrument equipped with FID (flame ionization detector) to measure CO 2 The detection temperature of the instrument was set to 300°C, the column temperature was set to 60°C, the carrier gas was 99.99% high-purity nitrogen, and the flow rate was controlled at 30 mL min -1 Under such conditions, the collected gas samples are tested to obtain accurate CO 2 Concentration data.

[0078] Then, according to the measured CO 2 The concentration data, combined with the sampling time, sampling frequency and related calculation formulas, can ultimately calculate the ecosystem CO 2 Cumulative emissions Re.

[0079] S103, determining the amount of carbon H taken away by vegetable production;

[0080] Specifically, the determination of the amount of carbon H taken away by vegetable production includes:

[0081] Determine the yield of vegetables; after the vegetables are mature, the yield of vegetables is measured by direct weighing, the unit is "g·m -2 ". This method can intuitively and accurately obtain the actual output quantity of vegetables per unit area in the vegetable field, providing basic data for subsequent calculations.

[0082] Convert vegetable yield to dry weight; convert the weighed fresh vegetable yield to dry weight. In actual operation, the vegetable samples can be dried to determine the ratio of fresh weight to dry weight, and then the overall yield can be converted to dry weight to eliminate the interference of moisture on carbon calculation and ensure data accuracy.

[0083] According to the dry weight of vegetables, the carbon content of corresponding vegetables is matched; according to the existing research results, the carbon content of different vegetables is determined. As shown in the document, the carbon content of celery, water spinach, Chinese cabbage, amaranth, Chinese cabbage, Chinese cabbage, Chinese chrysanthemum, and lettuce is 432, 418, 393, 328, 354, 427, 369, and 415 mg / kg respectively.

[0084] The amount of carbon H taken away by vegetable production is calculated based on the dry weight of vegetables and the carbon content of the corresponding vegetables. The amount of carbon H taken away by vegetable production is calculated based on the converted dry weight of vegetables and the carbon content of the corresponding vegetables. -2 ) multiplied by its carbon content (mg / kg), and then converted to "g·m -2 ” (1kg=1000g, 1mg=0.001g), we can get the value of the amount of carbon H taken away by vegetable production.

[0085] S104. Determination of the cumulative methane emissions from vegetable fields CH 4 , where CH 4 Refers to the ecosystem CO measured by the static dark box method 2 Cumulative emissions;

[0086] In a specific application, the method for determining the cumulative methane emissions from vegetable fields CH 4 ,include:

[0087] Collect gas samples using a collection device and record environmental factors when collecting the gas samples;

[0088] The collected gas samples are tested to obtain CH 4 Concentration data;

[0089] According to CH4 The concentration data, combined with the environmental factors when the gas samples were collected, were used to determine the cumulative methane emissions from the vegetable fields. 4 .

[0090] It should be noted that the measurement of the cumulative methane emissions from vegetable fields, CH 4 The steps and the static dark box method for measuring ecosystem CO 2 The steps for measuring the cumulative emission of methane Re can be the same, but the two are aimed at different objects. 4 The detailed process is described in detail.

[0091] S105, calculating the amount of carbon M brought into the field by the application of organic fertilizer;

[0092] Specifically, the calculation of the amount of carbon M brought into the field by applying organic fertilizer includes:

[0093] Get the weight m of organic fertilizer applied per unit area of ​​vegetable field, where the unit of m is kg·m -2 Specifically, the weight of organic fertilizer applied per unit area (per square meter) of vegetable field is obtained by actual measurement or by consulting fertilizer application records, and the value of m is determined in kg·m -2 For example, if in a certain vegetable field, it is measured that 2 kg of organic fertilizer is applied per square meter, then m = 2 kg·m -2 .

[0094] Determine the organic matter content ω of the applied organic fertilizer, the unit of ω is g·kg -1 ; This step can be done with the help of professional testing methods or by referring to the instructions of the organic fertilizer product to determine the organic matter content of the applied organic fertilizer in g·kg -1 Suppose a brand of organic fertilizer product description shows that its organic matter content is 300g·kg -1 , then ω=300g·kg -1 .

[0095] The formula M = m × ω × 0.58 is used to calculate the amount of carbon M brought into the field by the application of organic fertilizer. The unit of M is g·m -2 .

[0096] Substitute the determined values ​​of m and ω into the formula M = m × ω × 0.58 for calculation. For example, in the above example, M = 2kg·m -2 ×300g·kg -1 × 0.58 = 348 g·m -2 , and finally the value of the amount of carbon M brought into the field by the application of organic fertilizer is obtained.

[0097] S106. Calculate the net ecosystem carbon budget NECB;

[0098] GPP, Re, H, CH 4 Substitute M into the formula:

[0099] NECB=GPP-Re-H-CH 4 +M;

[0100] The value of NECB is calculated.

[0101] S200, using the net ecosystem carbon budget NECB to estimate the soil organic carbon storage in vegetable fields, where the calculation formula is as follows:

[0102] δSOC=0.07×NECB.

[0103] Furthermore, the static dark box method was used to measure ecosystem CO 2 Cumulative emissions Re and cumulative methane emissions from vegetable fields CH 4 When , the greenhouse gas emission flux F can also be calculated, and the calculation formula is as follows:

[0104]

[0105] Where F is CO 2 or CH 4 Emission flux, unit is mg·(m 2 h) -1 ; ρ is CO under standard conditions 2 or CH 4 Density, in kg·m -3 ; V is the volume of the collection device, in m 3 ; A is the soil surface area in the base of the collection device, in m 2 ; Δc / Δt is the rate of change of gas concentration in the box when collecting gas; T is the average temperature in the box when collecting gas, in ℃.

[0106] Greenhouse gas emission flux can directly reflect the emission or absorption rate of greenhouse gases per unit time and per unit area. By monitoring and calculating the carbon dioxide (CO 2 ) and methane (CH 4) and other greenhouse gas emission fluxes, we can clearly understand whether the ecosystem is a carbon source (emissions are greater than absorption) or a carbon sink (absorption is greater than emissions), as well as the dynamic changes in carbon balance. This helps to accurately assess the role and contribution of ecosystems in the global carbon cycle, and provides key data support for studying the carbon sink potential of terrestrial ecosystems. Changes in emission flux are sensitive indicators of environmental change. For example, when factors such as the amount of fertilizer applied to vegetable fields, irrigation methods, and planting structures change, greenhouse gas emission fluxes will change accordingly. By long-term monitoring of emission fluxes, we can timely detect the impact of these environmental changes on greenhouse gas emissions, and then analyze environmental change trends, providing a basis for environmental protection and ecological restoration. In addition, in agricultural production, understanding greenhouse gas emission fluxes can help optimize agricultural management measures. For example, by comparing emission fluxes under different fertilization strategies, farmers and agricultural managers can choose fertilization plans that can both ensure crop yields and reduce greenhouse gas emissions, and achieve low-carbon and sustainable agricultural development. At the same time, emission flux data can also help evaluate the impact of different planting patterns and irrigation methods on greenhouse gas emissions, and provide support for the promotion of green agricultural technologies.

[0107] Specifically, this application provides detailed steps for calculating the greenhouse gas emission flux F:

[0108] Determine the values ​​of each parameter: ρ is CO under standard conditions 2 Density, in kg·m -3 , which can be obtained by referring to the relevant physical constant table; V is the volume of the sampling box in this application. For example, the box made of PVC material in this study has a size of 40cm×40cm×50cm, and the converted volume; is the soil surface area in the sampling base, in m 2 , which needs to be determined according to the actual base size; Δc / Δt is the rate of change of gas concentration in the box when collecting gas, which is determined by CO at different time points. 2 The concentration data is calculated; T is the average temperature in the box when the gas is collected, in °C, which is measured and recorded by the box top thermometer during gas collection. Substitute the above-determined parameter values ​​into the formula to calculate the CO 2 Emission flux F.

[0109] In addition, this embodiment also provides a process for calculating the cumulative greenhouse gas emissions E. Specifically:

[0110]

[0111] Where E is the cumulative greenhouse gas emissions (kg·hm -2 ), n and i are the sampling times, and t is the sampling day (d).

[0112] More specifically:

[0113] E=∑(F×t×10-3 ×24) During the calculation process, the emission flux calculated for each sampling and the corresponding sampling days are substituted into the formula for cumulative calculation. Since the unit of emission flux is mg·(m 2 h) -1 ; To obtain the cumulative emissions in units, it is necessary to convert the units, that is, multiply by 10 -3 (convert mg to kg), then multiply by 24 (convert hourly emissions to daily emissions), and finally calculate the ecosystem CO 2 Cumulative emissions Re.

[0114] Example 2

[0115] This embodiment provides a system for estimating changes in soil organic carbon reserves in a vegetable field, which is used to implement the method for estimating changes in soil organic carbon reserves in a vegetable field in a short period of time as described above.

[0116] Specifically, the system includes a calculation module that performs calculations according to a preset calculation formula, according to NPP=NPP harvest +NPP residue +NPP exudate Calculate the net primary productivity NPP. Taking the lettuce planting area as an example, assuming that the NPP measured in a certain period is harvest 400g·m -2 , NPP residue 50g·m -2 , NPP exudate It is estimated to be 45 g·m -2 , then NPP = 400 + 50 + 45 = 495 g·m -2 The GPP is estimated by the ratio of NPP to 0.6, i.e., GPP = 495 ÷ 0.6 = 825 g·m -2 According to the formula NECB = GPP-Re-H-CH 4 +M calculates the net ecosystem carbon budget NECB. Assume that in this lettuce growing area, the Re measured at a certain stage is 25g·m -2 , CH 4 0.3 g·m -2 , H is calculated by conversion of output and carbon content to 120 g·m -2 The calculated M is 800 g·m -2 NECB = 825-25-120-0.3 + 800 = 1479.7 g·m -2 Finally, the change in soil organic carbon storage in the vegetable field, δSOC, was calculated according to the formula δSOC = 0.07 × NECB, i.e., δSOC = 0.07 × 1479.7 = 103.579 g·m -2 .

[0117] The system also includes a display module, which presents data in a visual interface, including a line graph showing the changing trend of δSOC and NECB in different planting areas over time, and a bar graph comparing the differences in data in each area. Based on the detailed data and intuitive visualization results provided by the system, agricultural managers can clearly understand the impact of different planting areas and different management measures (fertilization, irrigation, etc.) on soil organic carbon storage. As in the embodiment, by comparing the δSOC data of different vegetable planting areas, it is found that high organic fertilizer input has a significant effect on increasing soil carbon storage in water spinach planting areas. Managers can adjust fertilization strategies accordingly, promote reasonable fertilizer application in other areas, improve soil fertility, reduce unnecessary fertilizer input, and reduce production costs. Accurate soil organic carbon storage change data provides a reliable basis for studying the carbon cycle of agricultural ecosystems. Researchers can use the data accumulated by the system over a long period of time to deeply analyze the impact mechanism of different factors on the carbon cycle, and provide support for the development of more effective low-carbon agricultural technologies.

[0118] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings. In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0119] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0120] In addition, it should be noted that the use of words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this application. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for estimating the change of soil organic carbon storage in a vegetable field in a short period of time, characterized in that: Obtain the net ecosystem carbon budget NECB; The net ecosystem carbon budget (NECB) was used to estimate the soil organic carbon storage in vegetable fields, where the calculation formula is as follows: δSOC=0.07×NECB.

2. The method for estimating the change of soil organic carbon storage in a vegetable field in a short term according to claim 1, characterized in that: The net ecosystem carbon budget NECB is obtained as follows: Calculate gross primary productivity GPP; Determine the cumulative CO2 emissions Re of the ecosystem, where Re refers to the cumulative CO2 emissions of the ecosystem measured by the static dark box method; Determine the amount of carbon H taken away by vegetable production; Determine the cumulative methane emissions from vegetable fields (CH4), where CH4 refers to the cumulative CO2 emissions from the ecosystem measured by the static dark box method; Calculate the amount of carbon M brought into the field by applying organic fertilizer; Calculate the net ecosystem carbon budget NECB; Substitute GPP, Re, H, CH4 and M into the formula: NECB=GPP-Re-H-CH4+M; Calculate the value of NECB.

3. The method for estimating the change of soil organic carbon storage in a vegetable field in a short term according to claim 2, characterized in that: The calculation of gross primary productivity (GPP) includes: Obtain the net primary productivity NPP and calculate the gross primary productivity GPP using the formula GPP = NPP ÷ 0.6; Where NPP = NPP harvest +NP Presidue +NPP exudate ; NPP harvest Refers to the sum of the carbon content of the harvested parts of vegetable crops, determined by the potassium dichromate volumetric method; NPP residue Refers to the carbon content of the aboveground part of vegetables after harvest; it is estimated by measuring the carbon content of the remaining part of the unharvested vegetables in a set area; NPP exudate It refers to the sum of the carbon content of root exudates, which is estimated as 10% of the total biological carbon content.

4. The method for estimating the change of soil organic carbon storage in a vegetable field in a short term according to claim 2, characterized in that: The method of determining the cumulative CO2 emission Re of the ecosystem comprises: Collect gas samples using a collection device and record environmental factors when collecting the gas samples; Detect the collected gas samples to obtain CO2 concentration data; Based on the CO2 concentration data and the environmental factors when the gas samples were collected, the cumulative CO2 emissions Re of the ecosystem were determined.

5. The method for estimating the change of soil organic carbon storage in a vegetable field in a short term according to claim 4, characterized in that: The method of determining the cumulative CH4 emissions from vegetable fields includes: Collect gas samples using a collection device and record environmental factors when collecting the gas samples; Detect the collected gas samples to obtain CH4 concentration data; Based on the CH4 concentration data and the environmental factors when the gas samples were collected, the cumulative CH4 emissions from the vegetable fields were determined.

6. The method for estimating the change of soil organic carbon storage in a vegetable field in a short term according to claim 5, characterized in that: Calculate the greenhouse gas emission flux F, the calculation formula is as follows: Where F is the CO2 or CH4 emission flux, in mg·(m 2 h) -1 ; ρ is the density of CO2 or CH4 under standard conditions, in kg·m -3 ; V is the volume of the collection device, in m 3 ; A is the soil surface area in the base of the collection device, in m 2 ; Δc / Δt is the rate of change of gas concentration in the box when collecting gas; T is the average temperature in the box when collecting gas, in ℃.

7. The method for estimating the change of soil organic carbon storage in a vegetable field in a short term according to claim 2, characterized in that: The method of determining the amount of carbon H taken away by vegetable production includes: Determine vegetable yields; Convert vegetable yields to dry weight; Match the carbon content of the corresponding vegetables according to their dry weight; Based on the dry weight of vegetables and the carbon content of the corresponding vegetables, calculate the amount of carbon H taken away by vegetable production.

8. The method for estimating the change of soil organic carbon storage in a vegetable field in a short term according to claim 2, characterized in that: The calculation of the amount of carbon M brought into the field by applying organic fertilizer includes: Get the weight m of organic fertilizer applied per unit area of ​​vegetable field, where the unit of m is kg·m-2 Determine the organic matter content ω of the applied organic fertilizer, where the unit of ω is g·kg-1; The amount of carbon M brought into the field by the application of organic fertilizer is calculated using the formula M = m × ω × 0.58, where the unit of M is g·m-2.

9. A system for estimating changes in soil organic carbon reserves in vegetable fields, characterized in that: Used to implement the method for estimating changes in soil organic carbon stocks in vegetable fields in the short term as described in any one of claims 1 to 8.

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