A soil carbon-increasing and fertilizing method based on carbon-nitrogen ratio phased regulation of microbial community and application thereof in rice planting
Patent Information
- Application Number
- CN202610788220.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-03
- Publication Date
- 2026-08-18
AI Technical Summary
[0008]解决的技术问题：为解决现有稻田秸秆与猪粪联合施用技术中采用固定碳氮比进行一次性堆肥和施用，无法满足土壤固碳菌群与硝化菌群在水稻不同生育期对碳氮比的差异化需求，难以实现两类功能菌群的定向协同富集，且缺乏基于菌群监测的动态反馈调控手段导致培肥效果不稳定的问题，本发明提供一种基于碳氮比分阶段调控菌群的土壤增碳培肥方法及其在水稻种植中的应用，能够通过在水稻移栽前分阶段调控预腐熟物料的碳氮比和在水稻生育期内基于菌群丰度监测进行追肥调控，实现对稻田土壤固碳菌群和硝化菌群的阶段性定向富集与协同增效，在显著提高土壤有机碳含量的同时有效减少温室气体排放，并建立基于实时监测与反馈调节的精准培肥机制，确保培肥效果持续稳定
有益效果：与现有固定碳氮比联合施用秸秆与猪粪的技术相比，本发明通过分阶段调控碳氮比并结合菌群监测反馈调节，实现了稻田土壤功能菌群定向富集与土壤增碳减排的协同增效。在功能菌群调控方面，分阶段调控策略先以较低碳氮比促进固碳菌群增殖，再以较高碳氮比促进硝化菌群活化，克服了单一碳氮比条件下两类菌群难以兼顾的技术瓶颈，同步实现了两类功能菌群的高水平富集。固碳菌群产生的胞外多糖为硝化菌群提供了附着基质，硝化作用引起的微域环境变化又促进了碳素周转与固存，二者表现出明显的协同增效。在土壤增碳与温室气体减排方面，功能菌群代谢活动驱动了碳素的高效转化与稳定固存，土壤有机碳含量显著提升，同时氮素转化过程更为有序，有效降低了氧化亚氮和甲烷的排放，综合温室效应大幅下降，实现了增碳与减排的高度统一。在产量和养分利用方面，功能菌群的协同富集改善了稻田养分供应能力，水稻产量和氮肥利用率均显著提高。在培肥稳定性方面，菌群监测与反馈调控机制使培肥方案能够根据稻田实际菌群状态进行动态调整，避免了固定方案在不同条件下效果波动的问题，保证了培肥效果的持续稳定。当与生物炭联合使用时，二者产生互补协同效应，增产减排效果进一步增强。
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of agricultural soil improvement and rice cultivation technology, specifically relating to the field of soil carbon enrichment and fertilization technology based on the stage-regulated functional microbial community of carbon-nitrogen ratio, and particularly to a method for soil carbon enrichment and fertilization based on the stage-regulated microbial community of carbon-nitrogen ratio and its application in rice cultivation to achieve soil carbon enrichment, greenhouse gas emission reduction and yield increase. Background Technology
[0002] Improving soil organic matter content and reducing greenhouse gas emissions are key to achieving green and low-carbon rice production. Returning rice straw to the field and applying livestock manure are common measures to replenish soil organic matter. Rice straw is rich in carbon but relatively deficient in nitrogen, with a carbon-to-nitrogen ratio typically between 60 and 100; pig manure, on the other hand, has a higher nitrogen content but relatively lower carbon content, with a carbon-to-nitrogen ratio of approximately 10 to 20. Applying straw and pig manure together can adjust the carbon-to-nitrogen ratio of organic matter, promoting its decomposition and nutrient release in the soil.
[0003] Soil microorganisms are the core driving force behind the decomposition of organic matter, soil carbon sequestration, and nutrient form transformation. Different functional groups of microorganisms exhibit significant differences in their adaptability to the carbon-nitrogen ratio. For example, carbon-fixing bacteria, whose main metabolic characteristic is carbon assimilation, are more active under relatively low carbon-nitrogen ratios, converting carbon into their own cellular components and metabolites more efficiently. Conversely, nitrifying bacteria, which drive ammonia oxidation and nitrification, have a greater competitive advantage under relatively high carbon-nitrogen ratios, resulting in more vigorous nitrification. Studies have shown that when the carbon-nitrogen ratio is within an optimal range, overall microbial activity is vigorous, and the rates of organic matter decomposition and nutrient release are moderate.
[0004] Currently, most technical solutions for the combined application of straw and pig manure employ a fixed ratio. The two are mixed at a specific mass ratio and adjusted to an initial carbon-to-nitrogen ratio before being composted and applied to the paddy field in a single application. While this method improves upon the shortcomings of applying straw or pig manure alone to some extent, it still has significant technical limitations. The fixed ratio adjustment ignores the dynamic succession needs of soil functional microbiota in paddy fields during different growth stages of rice. During the seedling, tillering, jointing and booting stages, and even the grain-filling and ripening stages of rice growth, the dominant positions of carbon-fixing and nitrifying bacteria in the soil undergo regular shifts, and their preference for the carbon-to-nitrogen ratio also changes in stages. A suitable initial carbon-to-nitrogen ratio is insufficient to sustainably meet the needs of microbiota succession throughout the entire growth period.
[0005] Furthermore, a single carbon-to-nitrogen ratio cannot simultaneously achieve the targeted enrichment and synergistic effect of carbon-fixing and nitrifying bacteria. When the carbon-to-nitrogen ratio is relatively low, the activity of carbon-fixing bacteria increases, but the proliferation of nitrifying bacteria is inhibited; when the carbon-to-nitrogen ratio is relatively high, the activity of nitrifying bacteria increases, but the carbon assimilation efficiency of carbon-fixing bacteria decreases. This unbalanced regulatory approach makes it difficult to synergistically optimize the two processes of soil carbon increase and nitrogen transformation within the same technical solution.
[0006] Furthermore, existing technologies generally lack methods for dynamic feedback adjustment based on the actual abundance of functional microbial communities in paddy field soil. Differences in soil fertility, water management during the rice season, and climatic conditions all affect the microbial community response after material application. Fixed application patterns cannot be used to adjust fertilization strategies in a targeted manner, resulting in significant fluctuations in fertilization effects across different fields and rice seasons.
[0007] Based on the above problems, there is an urgent need to develop a method that can dynamically regulate the functional microbial community of paddy soil in stages, so as to achieve targeted enrichment of carbon-fixing bacteria and nitrifying bacteria during the main growth period of rice, thereby increasing the organic carbon content of the soil and reducing greenhouse gas emissions, and establishing a feedback regulation mechanism based on microbial community monitoring to achieve precision fertilization. Summary of the Invention
[0008] Technical Problem Solved: To address the shortcomings of existing rice straw and pig manure co-application technologies that use a fixed carbon-nitrogen ratio for one-time composting and application, which fails to meet the differentiated carbon-nitrogen ratio requirements of soil carbon-fixing and nitrifying bacteria at different rice growth stages, hindering the targeted synergistic enrichment of these two functional microbial communities, and lacking dynamic feedback control based on microbial community monitoring leading to unstable fertilization effects, this invention provides a soil carbon-enrichment and fertilization method based on phased regulation of microbial communities according to the carbon-nitrogen ratio and its application in rice cultivation. This method achieves phased targeted enrichment and synergistic enhancement of soil carbon-fixing and nitrifying bacteria by controlling the carbon-nitrogen ratio of pre-composted materials in stages before rice transplanting and by topdressing based on microbial abundance monitoring during the rice growth period. This significantly increases soil organic carbon content while effectively reducing greenhouse gas emissions, and establishes a precise fertilization mechanism based on real-time monitoring and feedback regulation to ensure continuous and stable fertilization effects.
[0009] Technical solution: A method for increasing soil carbon and enriching soil based on the staged regulation of microbial community by carbon-nitrogen ratio, comprising the following steps: (1) crushing air-dried rice straw and adjusting the moisture content to 50% to 60%; separating pig manure into solid and liquid components to obtain solid manure and liquid manure; (2) mixing the straw, solid manure and liquid manure from step (1) in proportion, adjusting the carbon-nitrogen ratio to 25:1 to 28:1, pre-composting at 50℃ to 55℃ for 7 to 10 days, turning the pile over every 3 days; (3) adding solid manure or liquid manure to the material obtained in step (2) and adjusting the carbon-nitrogen ratio to 30. The ratio of carbon to nitrogen is 1 to 32:1. The mixture is pre-fermented for 5 to 7 days at 55℃ to 60℃, and turned over every 3 days to obtain pre-fermented material. (4) The pre-fermented material from step (3) is applied as base fertilizer to the paddy field at a rate of 500-800 kg / mu. (5) During the rice growing season, paddy field soil samples are collected to monitor the abundance of carbon-fixing bacteria and nitrifying bacteria. When the relative abundance of carbon-fixing bacteria is less than 2.0%, a material with a carbon-nitrogen ratio of 25:1 to 28:1 is applied. When the relative abundance of nitrifying bacteria is less than 1.5%, a material with a carbon-nitrogen ratio of 30:1 to 32:1 is applied. In terms of fertilization stability, the microbial community monitoring and feedback regulation mechanism enables the fertilization program to be dynamically adjusted according to the actual microbial community status of the paddy field, avoiding the problem of fluctuation in the effect of a fixed program under different conditions, and ensuring the continuous stability of the fertilization effect. Extensive field trials have verified that when the relative abundance of carbon-fixing bacteria is below 2.0%, soil carbon assimilation efficiency decreases significantly, and the rate of organic carbon accumulation slows down markedly. When the relative abundance of nitrifying bacteria is below 1.5%, soil nitrification activity is insufficient, nitrogen conversion is hindered, and the absorption and utilization of available nitrogen by rice is affected. These thresholds were determined based on correlation analysis of soil carbon and nitrogen conversion rates under different bacterial abundance conditions, and serve as reliable criteria for topdressing regulation. When used in combination with biochar, the two produce a complementary and synergistic effect, further enhancing the yield-increasing and emission-reducing effects.
[0010] Preferably, in step (1), the rice straw is crushed to a particle size of 2 to 5 cm.
[0011] Preferably, the moisture content of the solid feces in step (1) is 70% to 80%.
[0012] Preferably, the mass ratio of air-dried straw, solid manure, and liquid manure in step (2) is (4-5):(2-2.5):(1-1.5).
[0013] Preferably, when applying base fertilizer in step (4), the pre-composted material is mixed with biochar and applied to the paddy field, and the amount of biochar added is 3% to 5% of the dry weight of the pre-composted material.
[0014] In step (5), soil samples were collected from paddy fields during the tillering, jointing and booting, and grain filling stages of rice for monitoring.
[0015] In step (5), the abundance of carbon-fixing bacteria and nitrifying bacteria is detected by 16S rRNA high-throughput sequencing or real-time fluorescence quantitative PCR.
[0016] The application of the above methods in rice cultivation.
[0017] The soil carbon-enriching and fertilization composition prepared by the above method.
[0018] Application of the above-mentioned soil carbon-enhancing and fertilization composition in rice cultivation to increase soil organic carbon content and yield, and reduce greenhouse gas emissions. Beneficial Effects: Compared with existing technologies that combine straw and pig manure with a fixed carbon-nitrogen ratio, this invention achieves synergistic effects of targeted enrichment of functional microbial communities and soil carbon increase and emission reduction by controlling the carbon-nitrogen ratio in stages and combining it with microbial community monitoring and feedback regulation. Regarding the regulation of functional microbial communities, the staged regulation strategy first promotes the proliferation of carbon-fixing bacteria with a lower carbon-nitrogen ratio, and then promotes the activation of nitrifying bacteria with a higher carbon-nitrogen ratio. This overcomes the technical bottleneck of the difficulty in simultaneously managing both types of microbial communities under a single carbon-nitrogen ratio, achieving high-level enrichment of both types of functional microbial communities. The extracellular polysaccharides produced by the carbon-fixing bacteria provide an attachment substrate for the nitrifying bacteria, and the microenvironmental changes caused by nitrification promote carbon turnover and fixation, showing a significant synergistic effect. In terms of soil carbon increase and greenhouse gas emission reduction, the metabolic activities of functional microbial communities drive efficient carbon conversion and stable fixation, significantly increasing soil organic carbon content. Simultaneously, the nitrogen conversion process becomes more orderly, effectively reducing emissions of nitrous oxide and methane, resulting in a significant decrease in the overall greenhouse effect and achieving a high degree of unity between carbon increase and emission reduction. In terms of yield and nutrient utilization, the synergistic enrichment of functional microbial communities improved the nutrient supply capacity of paddy fields, significantly increasing both rice yield and nitrogen fertilizer utilization. Regarding fertilization stability, the microbial community monitoring and feedback regulation mechanism enabled dynamic adjustments to the fertilization program based on the actual microbial community status in the paddy field, avoiding the fluctuations in effectiveness of fixed programs under different conditions and ensuring the continuous and stable fertilization effect. When used in conjunction with biochar, the two produce a complementary and synergistic effect, further enhancing the yield-increasing and emission-reducing effects. Detailed Implementation
[0019] The technical solution and technical effects of the present invention are further illustrated below with reference to specific embodiments and comparative examples. The following embodiments and comparative examples were conducted under the same experimental conditions. The experimental site was an experimental field in a major rice-producing area in southern China. The soil type was paddy soil with a basic fertility of 14.2 g / kg organic matter, 0.92 g / kg total nitrogen, 16.5 mg / kg available phosphorus, and 108 mg / kg available potassium.
[0020] Example 1 Air-dried rice straw is crushed to a particle size of 3 to 4 cm and its moisture content is adjusted to 55%. Pig manure is then subjected to solid-liquid separation to obtain solid feces and liquid waste, with the solid feces having a moisture content of approximately 75%.
[0021] Phase 1: Mix dried straw, solid manure, and liquid manure in a mass ratio of 4.5:2.2:1.3. The carbon-nitrogen ratio of the mixture is measured to be 26:1. Pre-compost at 52℃ for 8 days, turning the pile every 3 days.
[0022] Second stage: Add an appropriate amount of solid manure to the material obtained in the first stage, adjust the carbon-nitrogen ratio to 31:1, and continue pre-composting at 58℃ for 6 days, turning the pile over every 3 days.
[0023] Before application, the abundance of functional microbial communities in the material was detected by 16S rRNA sequencing. The relative abundance of carbon-fixing bacteria was 3.08%, and the relative abundance of nitrifying bacteria was 2.41%.
[0024] Pre-composted material was applied as base fertilizer at a rate of 600 kg / mu, evenly incorporated during field preparation and tillage before rice transplanting. The rice variety was Nanjing 9108. Soil samples were collected from the paddy fields during the tillering, jointing and booting, and grain-filling stages to monitor changes in functional microbial abundance. When the abundance of carbon-fixing bacteria was below 2.0%, 300 kg / mu of homologous material with a carbon-nitrogen ratio of 26:1 was applied as topdressing. When the abundance of nitrifying bacteria was below 1.5%, 200 kg / mu of homologous material with a carbon-nitrogen ratio of 31:1 was applied as topdressing. Routine topdressing management was carried out according to local practices.
[0025] Example 2 Air-dried rice straw is crushed to a particle size of 2 to 3 cm and its moisture content is adjusted to 50%. Pig manure is then subjected to solid-liquid separation, with the solid manure having a moisture content of approximately 78%.
[0026] The first stage: air-dried straw, solid manure and liquid manure are mixed in a mass ratio of 4:2.5:1.5, and the carbon-nitrogen ratio is measured to be 27:1. The mixture is pre-composted at 55℃ for 7 days, and turned over every 3 days.
[0027] Second stage: Add an appropriate amount of solid manure to the material, adjust the carbon-nitrogen ratio to 30:1, and continue pre-composting at 56℃ for 7 days, turning the pile over every 3 days.
[0028] Add biochar at 4% of the dry weight of the material. The biochar particle size should be less than 2mm. Mix it thoroughly with the pre-composted material.
[0029] The mixture was applied as base fertilizer to the paddy field at a rate of 550 kg / mu. The rice variety was the same as in Example 1. Topdressing was adjusted according to the results of microbial community monitoring.
[0030] Example 3 Air-dried rice straw is crushed to a particle size of 4 to 5 cm and its moisture content is adjusted to 60%. Pig manure is then subjected to solid-liquid separation, with the solid manure having a moisture content of approximately 72%.
[0031] The first stage involves mixing dried straw, solid manure, and liquid manure in a mass ratio of 5:2:1, with a carbon-to-nitrogen ratio of 25:1. The mixture is then pre-composted at 50°C for 10 days, with the pile turned over every 3 days.
[0032] Second stage: Adjust the carbon-nitrogen ratio of the material to 32:1, and continue pre-composting at 60℃ for 5 days, turning the pile over every 3 days.
[0033] The rice was applied as basal fertilizer at a rate of 700 kg / mu, using the same rice variety as in Example 1. During the rice's jointing and booting stage, based on the monitoring results of nitrifying bacteria abundance, 300 kg / mu of a material with a carbon-to-nitrogen ratio of 32:1 was applied as topdressing. The abundance of carbon-fixing bacteria remained normal, and topdressing was not triggered.
[0034] Comparative Example 1 Only air-dried rice straw was applied at a rate of 600 kg / mu, and other treatments were the same as in Example 1.
[0035] Comparative Example 2 Only solid manure was applied at a rate of 300 kg / mu, and other treatments were the same as in Example 1.
[0036] Comparative Example 3 Mix straw and pig manure at a mass ratio of 3:1, adjust the carbon-nitrogen ratio to about 30:1, and pre-compost at 55℃ for 15 days. Other treatments are the same as in Example 1.
[0037] Comparative Example 4 Apply compound fertilizer and urea according to the local conventional fertilization rate for rice, without applying organic materials, and other treatments are the same as in Example 1.
[0038] Comparative Example 5 The entire process of pre-fermentation and application was carried out using a carbon-to-nitrogen ratio of 26:1, and other treatments were the same as in Example 1.
[0039] Comparative Example 6 The entire process of pre-fermentation and application was carried out using a carbon-to-nitrogen ratio of 32:1, and other treatments were the same as in Example 1.
[0040] The results of the above treatment groups after rice harvest are shown in Table 1.
[0041] Table 1 Comparison of effects among treatment groups
[0042] Throughout the entire growth period of rice, the greenhouse gas emission flux in paddy fields was monitored using the static box method, and the results are shown in Table 2.
[0043] Table 2 Comparison of Cumulative Greenhouse Gas Emissions
[0044] Note: Methane emissions from paddy fields are the main source of greenhouse gases. Greenhouse gas emission data for each treatment were determined based on field static chamber monitoring results. The emissions of CO2, CH4, and N2O are the cumulative mass fluxes of the three gases, respectively. The overall GWP was calculated using the GWP100 coefficients from the IPCC Sixth Assessment Report (N2O = 298, CH4 = 25, CO2 = 1).
[0045] Results Analysis Compared with the conventional fixed carbon-nitrogen ratio treatment in Comparative Example 3, the soil organic carbon content in Examples 1 to 3 increased by 8% to 12%, and the rice yield increased by 10% to 13%, indicating that the phased carbon-nitrogen ratio regulation also has a significant synergistic effect under paddy field conditions.
[0046] Compared with the single low carbon-nitrogen ratio treatment in Comparative Example 5 and the single high carbon-nitrogen ratio treatment in Comparative Example 6, each example showed better performance in terms of the abundance of carbon-fixing bacteria and nitrifying bacteria, demonstrating that staged regulation can simultaneously promote the enrichment of two types of functional bacteria in the paddy field environment.
[0047] Example 2, due to the addition of biochar, showed the best performance in greenhouse gas emission reduction, with a 7.4% reduction in the overall global warming potential compared to Example 1, indicating that biochar and phased regulation have a synergistic emission reduction effect under rice cultivation conditions.
[0048] Comparative Example 2 showed the highest greenhouse gas emissions from the treatment using only pig manure (combined GWP of 15,500 kg CO2-e / hm²). 2 ), especially methane emissions (260 kg / hm 2 The results showed that the application of large amounts of pig manure to paddy fields would exacerbate the risk of greenhouse effect, while the method of this invention can effectively control this risk.
[0049] The present invention is not limited to the above embodiments; all embodiments described herein can be implemented and have the aforementioned good effects.
Claims
1. A method for soil carbon enrichment and fertilization based on phased regulation of microbial communities according to carbon-nitrogen ratio, characterized in that, Includes the following steps: (1) Crush the dried rice straw and adjust the moisture content to 50% to 60%; separate the pig manure into solid and liquid to obtain solid manure and liquid manure. (2) Mix the straw, solid manure and liquid manure from step (1) in proportion, adjust the carbon-nitrogen ratio to (25-28):1, pre-compost at 50℃ to 55℃ for 7 to 10 days, and turn the pile over every 3 days. (3) Add solid manure or liquid manure to the material obtained in step (2), adjust the carbon-nitrogen ratio to (30-32):1, and continue pre-composting at 55℃ to 60℃ for 5 to 7 days, turning the pile over every 3 days to obtain pre-composted material; (4) Apply the pre-composted material from step (3) as base fertilizer to the paddy field at a rate of 500-800 kg / mu; (5) Collect paddy field soil samples during the rice growing season and monitor the abundance of carbon-fixing bacteria and nitrifying bacteria. When the relative abundance of carbon-fixing bacteria is less than 2.0%, apply a material with a carbon-nitrogen ratio of (25-28):
1. When the relative abundance of nitrifying bacteria is less than 1.5%, apply a material with a carbon-nitrogen ratio of (30-32):
1.
2. The method according to claim 1, characterized in that, In step (1), the rice straw is crushed to a particle size of 2 to 5 cm.
3. The method according to claim 1, characterized in that, In step (1), the moisture content of the solid feces is 70% to 80%.
4. The method according to claim 1, characterized in that, In step (2), the mass ratio of air-dried straw, solid manure, and liquid manure is (4-5):(2-2.5):(1-1.5).
5. The method according to claim 1, characterized in that, When applying base fertilizer in step (4), the pre-composted material is mixed with biochar and applied to the paddy field. The amount of biochar added is 3% to 5% of the dry weight of the pre-composted material.
6. The method according to claim 1, characterized in that, In step (5), soil samples were collected from paddy fields during the tillering, jointing and booting, and grain filling stages of rice for monitoring.
7. The method according to claim 1, characterized in that, In step (5), the abundance of carbon-fixing bacteria and nitrifying bacteria is detected by 16S rRNA high-throughput sequencing or real-time fluorescence quantitative PCR.
8. The application of the method according to any one of claims 1 to 7 in rice cultivation.
9. The soil carbon-enriching and fertilization composition prepared by the method according to any one of claims 1 to 7.
10. The application of the soil carbon-enriching and fertilization composition according to claim 9 in rice cultivation to increase soil organic carbon content and yield, and reduce greenhouse gas emissions.