Carbon sequestration and emission reduction method of rice field with straw returning

Abstract

The present application relates to the field of agricultural environmental protection technology, and particularly relates to a rice field straw returning method for carbon fixation and emission reduction, which comprises the following steps: pretreating the straw by multi-stage crushing, mixing the pretreated straw with red mud, and gradient pyrolysis to prepare magnetic biochar, returning the magnetic biochar with specific bacteria, and constructing a three-layer buried stubble structure to improve the soil, and monitoring by a sensor and regulating by a neural network to realize carbon fixation and emission reduction and intelligent management, and further tracking the carbon flow and generating carbon sink certificates. The present application can efficiently fix carbon and reduce emissions through straw pretreatment, biochar preparation and bacteria-carbon coupling returning, can improve the soil structure by the three-layer buried stubble structure and humic acid, and can improve the air permeability, water retention and fertilizer retention performance of the soil, which is beneficial to crop growth, can realize precise management by the aid of sensor monitoring and neural network regulation, can accurately and safely measure the carbon by isotope labeling combined with block chain, and can provide strong support for carbon trading and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural environmental protection technology, in particular to a rice field straw returning method for carbon sequestration and emission reduction. BACKGROUND

[0002] Under the current background of sustainable agricultural development and climate change response, the reasonable treatment of rice straw and carbon sequestration and emission reduction technology have become a research hotspot. The traditional rice straw returning method has many drawbacks, which seriously restricts the improvement of agricultural ecological environment and the realization of carbon emission reduction target.

[0003] From the perspective of carbon sequestration and emission reduction, the common direct straw returning or simple incineration treatment method not only cannot fully utilize the carbon resources in straw, but also produces a large amount of greenhouse gases due to insufficient straw decomposition. The ordinary returning method lacks scientific regulation of straw treatment and microbial utilization, resulting in large methane emissions, low carbon sequestration efficiency, and difficulty in meeting the growing global demand for carbon emission reduction.

[0004] In terms of soil improvement, the traditional method cannot effectively improve the soil structure. Simple straw burial cannot form ideal pore structure, and the soil's air permeability, water retention and fertilizer retention cannot be significantly improved. Even the slow decomposition of straw may affect soil nutrient balance, which is not conducive to the growth and development of crop roots, and thus affects crop yield and quality.

[0005] For farmland management and carbon measurement, the traditional method relies on manual experience and lacks real-time and accurate monitoring and control means. It is difficult to timely grasp the key indicators such as soil Eh value, CH4 concentration and microbial activity, and it is difficult to adjust irrigation and fertilization strategies according to the actual situation of the soil, resulting in resource waste and environmental pollution. At the same time, in the field of carbon measurement and carbon trading, there is a lack of scientific and accurate measurement methods and data management system, which cannot provide reliable basis for carbon asset trading, hindering the healthy development of agricultural carbon trading market.

[0006] In summary, the existing rice straw returning technology has obvious shortcomings in carbon sequestration and emission reduction, soil improvement, and precise management and carbon measurement, and an innovative method is urgently needed to solve these problems to achieve green and sustainable development of agriculture. SUMMARY

[0007] Technical problems solved

[0008] In view of the above-mentioned defects of the prior art, the present application provides a rice field straw returning method for carbon sequestration and emission reduction, which can efficiently sequester carbon and reduce emissions through straw pretreatment, biochar preparation and fungus-carbon coupling returning; the three-layer buried stubble structure cooperates with humic acid to improve soil structure, improve its air permeability, water retention and fertilizer retention performance, and is beneficial to crop growth; with the help of sensor monitoring and neural network regulation, precise management is realized, and isotope labeling combined with blockchain is used for carbon measurement, so that the data is accurate and safe, and provides strong support for carbon trading and the like.

[0009] Technical scheme

[0010] In order to achieve the above-mentioned purposes, the present application is realized by the following technical scheme:

[0011] A rice field straw returning method for carbon sequestration and emission reduction, comprising the following steps:

[0012] S1. Multistage crushing and pretreatment of straw: a double-cutter roller differential type harvesting and crushing integrated machine is used to complete rice harvesting, the front cutter roller cuts longitudinally to form 5-8 cm straw segments, and the rear cutter roller transversely rubs the straw to make the fiber cleavage degree ≥85%, and the crushing uniformity variation coefficient ≤10%;

[0013] S2. Biochar gradient activation preparation: the straw obtained in step S1 is mixed with red mud catalyst at a mixing amount of 5-8%, and three-stage gradient pyrolysis is carried out under a mixed gas atmosphere with a CO2 and N2 volume ratio of 1:3, wherein the three-stage gradient pyrolysis is specifically: 200℃ / 30min→400℃ / 1h→550℃ / 2h, to generate magnetic biochar with a specific surface area ≥120m 2 / g, and a pore size distribution of a micropore and mesopore composite structure, wherein the micropore <2nm, the mesopore is 2-50nm, and the Fe3O4 loading in the magnetic biochar is 3-5%;

[0014] S3. Fungus-carbon coupling returning: halophilic methanotrophic bacteria and high-temperature-resistant cellulose-decomposing bacteria are fixed in the pores of the biochar at a ratio of 1:2, the survival rate of the bacteria agent is ≥90% / 30 days, and the biochar-bacteria agent composite is applied at 20-30% of the dry weight of the straw;

[0015] S4. Three-dimensional buried stubble and soil improvement: a hydraulic turnover plow and a rotary cultivator are combined to construct a three-layer buried stubble structure: a surface layer of 0-10cm biochar mixed layer, a middle layer of 10-25cm straw-bacteria agent composite layer, and a bottom layer of 25-40cm red mud solidification layer, and a humic acid binder is applied to form a honeycomb pore structure;

[0016] S5. Intelligent regulation and carbon measurement: a sensor array of LoRa communication is deployed to monitor the soil Eh value, CH4 concentration and microbial activity in real time, the irrigation strategy and bacteria agent activation frequency are dynamically adjusted through a convolutional neural network, and δ13C isotope labeling is used to track the flow direction of straw carbon and generate a blockchain carbon sink certificate.

[0017] Further, the red mud catalyst in step S2 needs to be modified by 0.5 mol / L hydrochloric acid, with a solid-liquid ratio of 1:5 to increase the specific surface area to 150 m 2 / g, and the magnetic loading is realized by coprecipitation method with Fe 2 + / Fe 3 molar ratio of 1:2 and an external magnetic field strength of 0.5T.

[0018] Further, the bacteria agent is immobilized by sodium alginate-biochar composite gel embedding technology, the pore size distribution matches the size of the bacteria body by ≥90%, and a micro-oxygen environment is constructed to maintain the activity of methanotrophic bacteria, and the dissolved oxygen in the micro-oxygen environment is 0.5-1.5mg / L.

[0019] Further, the intelligent control system comprises:

[0020] The multi-spectral unmanned aerial vehicle collects the rice field NDVI index and thermal infrared image every week to construct a three-dimensional emission model;

[0021] The edge computing gateway runs an LSTM neural network model, wherein the prediction accuracy R 2 ≥0.92;

[0022] The piezoelectric ceramic driven water valve and the electrically controlled bacteria agent atomizing nozzle, the response time of the piezoelectric ceramic driven water valve is ≤50ms, and the droplet diameter of the electrically controlled bacteria agent atomizing nozzle is 50-80μm.

[0023] Further, a regional adaptation model is established:

[0024] In the humid and hot climate zone, the red mud content is increased to 10% and the ventilation pipe is set, wherein the distance between the ventilation pipes is 1.5m;

[0025] In the saline-alkali area, the biochar is modified by 1mol / L NaOH to increase the porosity by 40%.

[0026] Further, the whole life cycle management includes:

[0027] The UHFRFID tag is used to track the moisture content and calorific value in the straw collection stage;

[0028] The microwave energy monitoring system is deployed in the biochar production stage, wherein the standing wave ratio is ≤1.5;

[0029] The carbon sink data generates tamper-proof credentials through the HyperledgerFabric architecture.

[0030] Further, the composite bacteria agent in step S3 adopts sodium alginate-biochar composite gel embedding technology, which specifically includes:

[0031] The magnetic biochar is mixed with a sodium alginate solution at a mass ratio of 1:3 to form a gel precursor;

[0032] The gel microspheres with a particle size of 50-200 mu m are prepared by microfluidic technology, and the matching degree of the pore diameter and the size of the bacteria is greater than or equal to 90%.

[0033] A gradient oxygen environment is constructed in the gel microspheres, specifically: the surface layer dissolved oxygen is 1.5-2.0 mg / L, the core zone dissolved oxygen is 0.3-0.8 mg / L, and 0.5-1.0% humic acid is simultaneously loaded as a slow-release nutrient source.

[0034] Further, the step S2 biochar preparation process is dynamically regulated by a machine learning model, specifically including:

[0035] An LSTM neural network model is constructed, and the input parameters include straw moisture content: 8-12%, red mud catalyst mixing amount: 5-8%, and heating rate: 10-20 DEG C / min;

[0036] The CO2 and N2 mixed gas flow rate in the carbonization process is 0.8-1.2 m / s, and the specific surface area data of the product is collected in real time, the model parameters are optimized through transfer learning, and the prediction accuracy R 2 ≥0.93;

[0037] According to the model output, the microwave power density and the injection rate of the activator NH3 are dynamically adjusted, the microwave power density is 1.5-2.0 W / cm 3 , and the specific surface area of the biochar is stabilized at 120-150 m 2 / g interval.

[0038] Further, the blockchain carbon sink certificate generation method includes:

[0039] The value of δ13C is measured by laser ablation-isotope mass spectrometry: -28 ‰ to -26 ‰, and a straw carbon fingerprint database is established;

[0040] A private chain node based on HyperledgerFabric is deployed, each block contains a timestamp, GPS coordinates and a carbon sequestration amount hash value, wherein the error of each block timestamp is less than or equal to 1s;

[0041] A zero-knowledge proof algorithm is introduced to verify the authenticity of the data, and to ensure that the privacy data is not leaked during carbon asset transaction.

[0042] Beneficial effects

[0043] Compared with the known prior art, the technical scheme provided by the present application has the following advantages

[0044] Beneficial effects:

[0045] I. The three-layer buried stub structure constructed by the combined operation of the hydraulic turnover plow and the rotary cultivator, the surface biochar mixed layer, the middle straw-bacterial agent composite layer, and the bottom red mud solidification layer, matched with humic acid binder to form a honeycomb pore structure, can enhance the soil permeability, water retention and fertilizer retention, and the red mud solidification layer can also prevent bottom leakage and optimize the soil physical and chemical properties to create an excellent environment for crop growth.

[0046] II. The straw multi-stage crushing pretreatment makes the straw fiber cleavage degree ≥85% and the uniformity coefficient of crushing ≤10%, and the subsequent gradient activation preparation of biochar generates magnetic biochar with a specific surface area ≥120m 2 / g. Coupling the biochar with specific proportions of salt-tolerant methanotrophic bacteria and high-temperature-resistant cellulolytic bacteria into the field can fully utilize the characteristics of microorganisms and biochar, accelerate the fixation and conversion of straw carbon in the soil, inhibit methane generation, effectively reduce the carbon emission of paddy fields, and improve the carbon sequestration capacity.

[0047] III. The LoRa communication sensor array is used to monitor the key indicators of the soil in real time, and the convolutional neural network is used to dynamically adjust the irrigation strategy and the frequency of bacterial agent activation to realize precision agricultural management and improve resource utilization efficiency. At the same time, the δ13C isotope label is used to track the flow direction of straw carbon, and the blockchain technology is used to generate tamper-proof carbon sink certificates to ensure the scientific accuracy of carbon measurement and provide solid data support and security for carbon trading and carbon asset management. DETAILED DESCRIPTION

[0048] To make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in combination with the embodiments in the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0049] The present application will be further described below in combination with the embodiments.

[0050] Embodiment 1: Basic technical solution

[0051] S1. Straw multi-stage crushing and pretreatment

[0052] The double knife roller differential type harvesting and crushing integrated machine (model: JQ-3000) is used for rice harvesting and straw crushing. The front knife roller cuts longitudinally to form straw segments with a length of 6 cm, and the rear knife roller processes the straw transversely to achieve a fiber splitting degree of 87% (≥85%) and a crushing uniformity variation coefficient of 8% (≤10%). The moisture content of the crushed straw is controlled at 10%, and is calibrated in real time by an infrared moisture meter (accuracy ±0.5%). The crushed straw needs to enter the next process within 48 hours to prevent fiber oxidation degradation.

[0053] S2. Preparation of activated biochar by gradient

[0054] Modification of red mud catalyst:

[0055] The red mud is mixed with 0.5 mol / L hydrochloric acid at a solid-liquid ratio of 1:5, stirred for 2 h, and then centrifuged at 3000 rpm for 10 min. After drying, the modified red mud catalyst is obtained, with a specific surface area increased to 150 m 2 / g (original red mud is 80 m 2 / g).

[0056] Magnetic loading is achieved by coprecipitation: Fe 2+ and Fe 3+ are mixed at a molar ratio of 1:2, and the uniform Fe3O4 nanoparticles are formed under the condition of an external magnetic field strength of 0.5 T.

[0057] Mixing and gradient pyrolysis:

[0058] The straw obtained in step S1 is mixed with modified red mud at a mixing amount of 6%, and is placed in a mixed gas atmosphere with a CO2 and N2 volume ratio of 1:3 for three-stage gradient pyrolysis:

[0059] First stage: 200℃ / 30min (removal of volatile organic compounds in the initial stage of pyrolysis, heating rate 10℃ / min);

[0060] Second stage: 400℃ / 1h (promote carbon skeleton formation, microwave power density 1.5 W / cm 3 );

[0061] Third stage: 550℃ / 2h (Fe3O4 loading amount reaches 4%, microwave power density increases to 2.0 W / cm 3 ).

[0062] The final magnetic biochar has a specific surface area of 135 m 2 / g (≥120 m 2 / g), a pore size distribution of a composite structure of micropores (<2 nm) and mesopores (2-50 nm), and a porosity of 45%.

[0063] S3. Fungus-carbon coupling and field application

[0064] Bacterial agent embedding:

[0065] The halophilic methanotroph (strain number: Methylococcus sp. HY-01) and the thermophilic cellulolytic bacteria (strain number: Thermobifida fusca TF-02) are mixed at a ratio of 1:2.

[0066] Fixed in the pores of biochar by sodium alginate-biochar composite gel embedding technology:

[0067] Gel microspheres particle size: 100 μm;

[0068] Pore matching degree: 92% (≥ 90%);

[0069] Dissolved oxygen gradient: 1.8 mg / L at the surface, 0.5 mg / L in the core area.

[0070] Bacterial agent survival rate within 30 days remains 93% (≥ 90%), humic acid slow-release agent addition amount 1.0%.

[0071] Proportioning: biochar-bacterial agent complex is applied to the field at a proportion of 25% of the dry weight of the straw, using a pneumatic spreader (spreading uniformity ≥ 95%).

[0072] S4. Three-dimensional buried stubble and soil improvement

[0073] A hydraulic turnover plow (model: HF-500) and a rotary cultivator (model: XG-2000) are used to construct a three-layer buried stubble structure:

[0074] Surface layer (0-10 cm): biochar mixed layer, with humic acid binder (addition amount 2 kg / acre) to form a honeycomb pore structure (porosity 45%), improving soil aeration;

[0075] Middle layer (10-25 cm): straw-bacterial agent composite layer, straw density 300 kg / acre, microbial activity ATP content ≥ 5 nmol / g;

[0076] Bottom layer (25-40 cm): red mud solidification layer, red mud content 8%, compaction degree 90%, preventing bottom layer leakage.

[0077] S5. Intelligent control and carbon measurement

[0078] Sensor deployment:

[0079] LoRa sensor array (model: LS-200) is deployed every 10m x 10m grid in the field to monitor in real time:

[0080] Soil Eh value (-150 to +200 mV);

[0081] CH4 concentration (accuracy ±0.1ppm);

[0082] Microbial activity (ATP detector accuracy ±0.2 nmol / g).

[0083] Dynamic regulation:

[0084] The system analyzes sensor data using a convolutional neural network (CNN) model to dynamically adjust irrigation water volume (error ≤ 5%) and microbial agent atomizing nozzle parameters (droplet diameter 60 μm, claims range 50-80 μm).

[0085] The edge computing gateway (model: ECG-5000) runs an LSTM model (R 2 =0.94 (claims ≥0.92), the predicted peak CH4 emission time error is ≤10min.

[0086] Carbon tracking and certificate generation:

[0087] The application of δ¹³C isotope labeling technology (δ¹³C value -27‰) to track the carbon flow in straw;

[0088] The blockchain carbon sequestration certificate is generated using the Hyperledger Fabric architecture. Each block contains a timestamp (error ≤ 1s), GPS coordinates, and a hash value of the carbon sequestration amount. A zero-knowledge proof algorithm (ZKP-200 protocol) is introduced to ensure data privacy.

[0089] Example 2: Adaptation scheme for hot and humid climate zones

[0090] Based on Example 1, the following parameters were adjusted:

[0091] The amount of red mud was increased to 10%, and ventilation pipes (spaced 1.5m apart) were installed at the bottom layer, made of PVC material (50mm in diameter) to enhance soil permeability.

[0092] The pyrolysis heating rate was adjusted to 15℃ / min, the pyrolysis cycle was shortened to 2.5h, and the microwave power density was stabilized at 1.8W / cm³. 3 ;

[0093] Intelligent control system upgrade:

[0094] The response time of the piezoelectric ceramic driven water valve has been optimized to 45ms;

[0095] A multispectral UAV (model: MSD-1000) collects NDVI data weekly (resolution 0.1m). 2 Combined with thermal infrared images, a three-dimensional emission model was constructed (error ≤ 8%).

[0096] Example 3: Saline-alkali land adaptation scheme

[0097] Biochar modification: reacting biochar with 1 mol / L NaOH solution for 24 h, porosity increased by 42%, specific surface area increased to 145 m 2 / g;

[0098] Formulation adjustment of microbial agent: increasing the proportion of halophilic bacteria to 1:1, and adjusting the dissolved oxygen gradient to 2.0 mg / L at the surface layer and 0.8 mg / L at the core area;

[0099] Carbon measurement optimization: measuring δ13C value (error ± 0.3 ‰) by laser ablation-isotope mass spectrometry (LA-ICP-MS), and deploying a microwave energy monitoring system (standing wave ratio ≤ 1.5).

[0100] Comparative example

[0101] Comparative example 1: single temperature pyrolysis

[0102] Step S2 is changed to single temperature pyrolysis at 550°C for 3h, and the rest is the same as example 1.

[0103] Results: the specific surface area of biochar is only 90 m 2 / g, Fe3O4 is unevenly loaded (3.2%), and the porosity is reduced to 30%.

[0104] Comparative example 2: without using microbial agent embedding technology

[0105] In step S3, the microbial agent is directly mixed with the biochar, and gel embedding is not used.

[0106] Results: the survival rate of the microbial agent is reduced to 70% after 30 days, the CH4 emission reduction amount is reduced by 35%, and the microbial activity retention rate is only 75%.

[0107] Comparative example 3: traditional irrigation management

[0108] The intelligent control system of step S5 is omitted, and manual irrigation and fertilization are used.

[0109] Results: the soil Eh value fluctuates ± 50 mV, the microbial activity retention rate is only 82%, and the CH4 emission reduction amount is reduced by 58%.

[0110] Comparison table:

[0111] Table 1: Comparison of biochar performance

[0112]

[0113] Examples 1-3 are modified by gradient pyrolysis and red mud, which significantly improves the specific surface area and porosity of biochar. Comparative example 1 has decreased performance due to single temperature pyrolysis. The saline-alkali land adaptation scheme (example 3) further optimizes the pore structure by NaOH modification, which is suitable for high salt environment.

[0114] Table 2: Activity of microbial agent and emission reduction effect

[0115]

[0116] The bacteria-carbon embedding technology of Example 1 ensures long-term activity of the microbial agent, and the CH4 emission reduction amount is increased by 55%. The non-embedded microbial agent of Comparative Example 2 is dead, and the emission reduction efficiency is greatly reduced.

[0117] Table 3: Performance of intelligent control system

[0118]

[0119]

[0120] The intelligent control system of Examples 1-2 has significantly better irrigation accuracy and response speed than traditional management (Comparative Example 3) through real-time data optimization, with carbon tracking error controlled within 0.5‰, meeting the carbon trading certification requirements.

[0121] In summary, Example 1 realizes carbon sequestration efficiency of 2.8 tCO2e / acre, CH4 emission reduction amount of 15.2 kg / acre, and microbial activity retention rate of 95% through gradient pyrolysis, bacteria-carbon coupling, and intelligent control technology; Example 2 realizes CH4 peak prediction accuracy of 94% and carbon sink certificate generation efficiency improvement of 20% through ventilation underdrain and LSTM model optimization in hot and humid climate areas; and Example 3 realizes NDVI index error of ≤8% and carbon asset transaction security guaranteed by zero-knowledge proof algorithm by optimizing porosity and microbial agent ratio for saline-alkali land.

[0122] The above examples are used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing examples, or make equivalent substitutions for part of the technical features; and these modifications or substitutions will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for carbon sequestration and emission reduction of rice field straw returning to field, characterized in that, The method comprises the following steps: S1. Multistage crushing and pretreatment of straw: A double-cutter roller differential type harvesting and crushing all-in-one machine is used to complete rice harvesting, the front cutter roller cuts longitudinally to form 5-8 cm straw segments, and the rear cutter roller processes transversely to make the fiber lysis degree ≥ 85%, and the crushing uniformity coefficient ≤ 10%; S2. Gradient activation preparation of biochar: the straw obtained in step S1 is mixed with the red mud catalyst according to the mixing amount of 5-8%, and three-stage gradient pyrolysis is carried out under a mixed gas atmosphere with a CO2 and N2 volume ratio of 1:3, wherein the three-stage gradient pyrolysis is specifically: 200 DEG C / 30 min→400 DEG C / 1 h→550 DEG C / 2 h, to generate magnetic biochar with a specific surface area ≥120 m 2 / g, a pore size distribution of a micropore and mesopore composite structure, wherein the micropore is <2 nm, the mesopore is 2-50 nm, and the Fe3O4 loading in the magnetic biochar is 3-5%. S3. Bacteria-carbon coupling return to field: The salt-tolerant methanotrophic bacteria and the high-temperature-resistant cellulose-decomposing bacteria are fixed in the pores of biochar at a ratio of 1:2, the survival rate of the bacteria agent is ≥ 90% / 30 days, and the biochar-bacteria agent composite is applied at 20-30% of the dry weight of the straw; S4. Three-dimensional buried mulching and soil improvement: A hydraulic turnover plow and a rotary cultivator are combined to construct a three-layer buried mulch structure: a surface 0-10 cm biochar mixing layer, a middle layer 10-25 cm straw-bacteria agent composite layer, and a bottom layer 25-40 cm red mud solidification layer, and a humic acid binder is applied to form a honeycomb pore structure; S5. Intelligent regulation and carbon measurement: Deploy sensor array with LoRa communication to monitor soil Eh value, CH4 concentration and microbial activity in real time, dynamically adjust irrigation strategy and microbial agent activation frequency through convolutional neural network, and apply δ 13 C isotope labeling to track straw carbon flow and generate blockchain carbon sink certificate.

2. The carbon sequestration and emission reduction method of rice field straw returning according to claim 1, characterized in that, The red mud catalyst in the step S2 needs to be modified by hydrochloric acid with a concentration of 0.5 mol / L, wherein the solid-liquid ratio is 1:5, so that the specific surface area is increased to 150 m 2 / g, and the magnetic loading is realized by a coprecipitation method of Fe 2 + / Fe 3 + with a molar ratio of 1:2 and an applied magnetic field strength of 0.5 T.

3. The carbon sequestration and emission reduction method of rice field straw returning according to claim 1, characterized in that, The bacteria agent is fixed by using a sodium alginate-biochar composite gel embedding technology, the pore size distribution and the bacteria size matching degree are ≥ 90%, and a micro-oxygen environment is constructed to maintain the activity of the methanotrophic bacteria, and the dissolved oxygen in the micro-oxygen environment is 0.5-1.5 mg / L.

4. The carbon sequestration and emission reduction method of rice field straw returning according to claim 1, characterized in that, The intelligent control system comprises: A multispectral unmanned aerial vehicle collects rice field NDVI index and thermal infrared images every week to construct a three-dimensional emission model; The edge computing gateway runs an LSTM neural network model, wherein the prediction accuracy R 2 ≥ 0.92; A piezoelectric ceramic driven water valve and an electrically controlled bacteria agent atomizing nozzle, the response time of the piezoelectric ceramic driven water valve is ≤ 50 ms, and the droplet diameter of the electrically controlled bacteria agent atomizing nozzle is 50-80 μm.

5. The carbon sequestration and emission reduction method of rice field straw returning according to claim 1, characterized in that, A regional adaptation model is established: In a humid and hot climate zone, the red mud content is increased to 10% and a ventilation pipe is set, and the distance between the ventilation pipes is 1.5 m; In a saline-alkali area, the biochar is modified by 1 mol / L NaOH to increase the porosity by 40%.

6. The carbon sequestration and emission reduction method of rice field with straw returning according to claim 1, characterized in that, The whole life cycle management includes: UHFRFID tags are used to track the moisture content and calorific value in the straw collection stage; A microwave energy monitoring system is deployed in the biochar production stage, and the standing wave ratio is ≤ 1.5; Carbon sink data are used to generate tamper-proof certificates through the Hyperledger Fabric architecture.

7. The carbon-sequestering and emission-reducing method of claim 1, wherein the rice field is a paddy field. The composite bacteria agent in step S3 uses a sodium alginate-biochar composite gel embedding technology, which specifically includes: Mixing magnetic biochar and sodium alginate solution at a mass ratio of 1:3 to form a gel precursor; Preparing gel microspheres with a particle size of 50-200 μm through microfluidic technology, and the pore diameter and bacteria size matching degree are ≥ 90%; A gradient oxygen environment is constructed in the gel microspheres, specifically: the surface dissolved oxygen is 1.5-2.0 mg / L, the core zone dissolved oxygen is 0.3-0.8 mg / L, and 0.5-1.0% humic acid is simultaneously loaded as a slow-release nutrient source.

8. The carbon-sequestering and emission-reducing method of claim 2, wherein the rice field is a paddy field. The biochar preparation process in step S2 is dynamically regulated by a machine learning model, which specifically includes: An LSTM neural network model is constructed, and the input parameters include straw moisture content: 8-12%, red mud catalyst content: 5-8%, and heating rate: 10-20 ℃ / min; Real-time acquisition of CO2 and N2 mixed gas flow rate of 0.8-1.2 m / s during carbonization and product specific surface area data, through transfer learning to optimize model parameters, the prediction accuracy R 2 ≥0.93; The microwave power density and the injection rate of the activating agent NH3 were dynamically adjusted according to the model output, and the microwave power density was 1.5-2.0 W / cm 3 The specific surface area of the biochar was stabilized in the interval of 120-150 m 2 / g. 9.The carbon sequestration and emission reduction rice field straw return method according to claim 5, characterized in that, The blockchain carbon sink certificate generation method comprises: The δ values were determined by laser ablation-isotope mass spectrometry 13 C value: -28‰ to -26‰, establish straw carbon fingerprint database; Deploying private chain nodes based on Hyperledger Fabric, each block contains a timestamp, GPS coordinates and carbon sequestration amount hash value, and the error of each block timestamp is ≤1s; Introducing zero-knowledge proof algorithm to verify data authenticity and ensure that private data is not leaked during carbon asset transaction.

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