Heavy salinized soil carbon sequestration and sink increasing and modifying agent as well as preparation method and application thereof
By preparing the straw of the scattered rice grass into biomass charcoal and applying it to heavy salinized soil, the problem of ecological function decline caused by salinization in coastal wetland soil is solved, and the soil organic carbon content is significantly improved and carbon fixation effect is achieved, and the cost is low, which is suitable for large-scale promotion.
Patent Information
- Application Number
- CN202510001550.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2025-05-06
AI Technical Summary
The soil in coastal wetlands has lost nutrients such as carbon, nitrogen, and phosphorus due to salinization, alkalinization and desertification, and the soil ecological function has declined. The existing technology has limitations in cost and application methods, making it difficult to effectively utilize the straw of the flower rice and grass for resource utilization and carbon sequestration.
By collecting the straw of the squid grass, crushing and high-temperature pyrolysis, the squid grass biomass charcoal was prepared and applied to the heavy salted soil according to 1: (3-5), the physicochemical properties, nutrient content and microbial community structure of the soil are improved, and the growth of salt marsh plants and carbon sequestration are promoted.
It significantly improves the organic carbon content and microbial activity of the soil, enhances the carbon fixation capacity of the soil, improves the ecological function of the wetlands, and is cheap, suitable for large-scale promotion.
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Figure CN119929773A_ABST
Abstract
Description
Technical Field
[0001] The invention discloses a carbon fixation and sink enhancement agent for heavily saline soil, a preparation method and application thereof, and belongs to the technical field of ecological environment improvement. Background Art
[0002] The soil carbon pool in coastal wetlands is one of the important carbon pools. The carbon storage in mangrove wetlands can reach 43.49-79.14 t / hm2. 2 , while the carbon storage of Spartina alterniflora wetland can reach 25.50t / hm 2 , which has considerable room for improvement. Salt marsh carbon sequestration and sink technology is a new hot topic. How to utilize the vast coastal wetlands and make them important carbon sinks is of great significance for reducing the negative ecological effects of carbon dioxide emissions.
[0003] As the main environmental matrix of wetland ecosystems, wetland soil is the basis for maintaining and ensuring the normal functions of wetlands. However, during the degradation of coastal wetlands, the originally fragile soils often undergo salinization, alkalization and desertification, and a large amount of nutrients such as carbon, nitrogen and phosphorus are lost from wetland soils, resulting in a decline in soil ecological functions. Among them, due to the long-term scouring and infiltration of seawater, the salinization problem of coastal wetland soils is the most prominent. At present, many physical, chemical and biological measures are used to repair and improve the soil of heavily saline soils in coastal wetlands. However, due to the cost and application methods, there are often certain limitations in practical applications. Therefore, the development of a low-cost, environmentally friendly soil conditioner is of great significance for the treatment of heavily saline soils in coastal wetlands.
[0004] Spartina alterniflora is a perennial herb with the characteristics of a wide distribution and large biomass. Since its introduction, Spartina alterniflora has continued to expand rapidly in my country as an invasive species. The latest remote sensing images show that the total occurrence area of Spartina alterniflora in the country has reached 68,000 hectares. In order to restore the wetland function and local ecology, my country has launched a special action to prevent and control Spartina alterniflora. Since 2019, large-scale Spartina alterniflora control projects have been carried out in various places. As a result, the resource utilization of the large amount of Spartina alterniflora straw produced by the control has become a major problem, and there is an urgent need to develop a method to achieve resource utilization of Spartina alterniflora that is environmentally friendly. Summary of the invention
[0005] Purpose of the invention: In view of the above technical problems, the present invention provides a carbon fixation and carbon sink enhancement agent for heavily saline soil, a preparation method and application, the purpose of which is to adjust the physical and chemical properties of the soil by preparing and adding soil improvers, and indirectly change the composition and structure of soil organic carbon through the action of salt marsh plants and salt marsh microorganisms, thereby increasing the carbon storage of the coastal carbon pool. This method solves the problem of the lack of existing Spartina alterniflora straw resource utilization technology and heavily saline soil carbon fixation and carbon sink enhancement technology. The method is efficient, fast, low-cost, and has obvious effects.
[0006] Technical solution: In order to achieve the above-mentioned invention object, the present invention adopts the following technical solution:
[0007] A method for preparing a carbon fixation and sink enhancement agent for heavily saline soil, comprising the following steps:
[0008] The Spartina alterniflora straw is collected, crushed, subjected to high temperature pyrolysis treatment at 350°C-550°C for 40-80 minutes, and cooled to obtain the Spartina alterniflora biomass charcoal, which is the heavy saline soil carbon fixation and sink and improver.
[0009] As a specific implementation scheme, the Spartina alterniflora straw is dried to constant weight before being crushed; the crushing is performed using a grinder and passed through a 100-mesh sieve (0.149 mm) for later use; during the high-temperature pyrolysis treatment, the Spartina alterniflora straw powder is tightly wrapped with tin foil and subjected to high-temperature pyrolysis in a crucible.
[0010] The present invention also provides a heavily saline soil carbon fixation and carbon sink enhancement agent and an improver, wherein the heavily saline soil carbon fixation and carbon sink enhancement agent and an improver is the Spartina alterniflora biomass charcoal prepared by the above-mentioned preparation method.
[0011] The present invention also provides the application of the heavily saline soil carbon fixation and sink enhancement agent in improving heavily saline soil.
[0012] As a specific embodiment, the improving heavily saline soil includes changing its physical and chemical properties, nutrient content and microbial community structure.
[0013] As a specific implementation scheme, the improvement of heavily saline soil includes improving the carbon fixation effect of salt marsh plants and heavily saline soil, and increasing the organic carbon content.
[0014] Furthermore, the salt marsh plants include one or more of Spartina alterniflora, Suaeda salsa, and Phragmites australis.
[0015] Finally, the present invention provides a method for carbon fixation and carbon sink enhancement and improvement of heavily saline soil, comprising improving the heavily saline soil using the heavily saline soil carbon fixation and carbon sink enhancement and improver.
[0016] As a specific implementation scheme, the method for carbon fixation and sink enhancement and improvement of heavily saline soil comprises the following steps:
[0017] Spread the Spartina alterniflora biochar at a charcoal-to-soil ratio (w:w) of 1:(3-5) on the heavily saline soil where carbon fixation and carbon sink enhancement are required, and mix it evenly with the surface soil.
[0018] As a further solution, the surface soil refers to the soil layer 0-30 cm below the soil surface.
[0019] The invention provides a carbon fixation and carbon sink enhancement agent for heavily saline soil and an improver, and its preparation and application. The technical principle is to prepare a soil carbon fixation and carbon sink enhancement agent and an improver using discarded Spartina alterniflora straw, and apply it to the heavily saline soil in the coastal wetland that needs to be improved. Improve the physicochemical properties, nutrient conditions, soil hydrolase activity and microbial community structure of heavily saline soil. After the salt marsh plants growing in the area absorb available nitrogen and phosphorus, their own nutrient conditions are changed, and they grow more vigorously, which can improve their carbon fixation efficiency and increase the content of soil organic carbon. At the same time, the addition of biochar can also directly increase the total organic carbon content in the soil. After biochar is added to the soil, it can also provide a carbon source for soil microorganisms to enhance their activities. On the other hand, the addition of biochar improvers will also increase the abundance of some functional flora in the soil, such as aerobic anoxygenic photosynthetic bacteria, which can increase microbial source carbon. The activity of the dominant flora related to carbon metabolism will decrease, which can reduce the soil carbon decomposition rate, which is beneficial to the self-fixation of the carbon pool, thereby achieving the effect of carbon fixation and carbon sink enhancement.
[0020] The heavy saline soil carbon fixation and sink enhancement and improver provided by the present invention and its preparation and application can be used in heavy saline soil, mainly in heavy saline areas covered with vegetation, but in heavy saline areas without vegetation coverage, the technology can also play a certain role. Therefore, the application range of the technology is relatively wide and can be promoted and applied on a large scale.
[0021] The heavy saline soil carbon fixation and sink enhancement and improver provided by the present invention and its preparation and application are simple to prepare, the raw materials are easily available, and the price is low. The invasive plant Spartina alterniflora straw is used as a carbon source supplement, which is environmentally friendly. After the soil carbon fixation and sink enhancement and improver are added, the growth of salt marsh plants can be promoted, and the soil microbial community structure can be changed at the same time, which can greatly improve the carbon fixation effect of plants and soil.
[0022] Through the preparation and application technology of carbon fixation and improvement agent for heavy saline soil provided by the present invention, the organic carbon fixation of salt marsh soil will be significantly improved. Experiments have shown that by adding Spartina alterniflora biochar to condition heavy saline soil, the increase in soil organic carbon content can reach 200% by the end of the experiment.
[0023] Technical effect: Compared with the prior art, the present invention provides a carbon fixation and sink and improver for heavily saline soil, a preparation method and application. The technology is environmentally friendly, the selected materials are easy to obtain and can realize waste utilization. By implementing this technology, the physical and chemical properties of heavily saline soil are improved, and the nutrient content, carbon content and hydrolase activity in the soil are significantly increased. The soil microbial community structure has also changed significantly.
[0024] 1. The present invention reasonably and fully utilizes the straw of Spartina alterniflora, saving the cost of additional carbon sources while reducing the incompatibility of salt marsh microorganisms to unfamiliar carbon sources. It solves the technical problem of carbon fixation and sink enhancement in an environmentally friendly way;
[0025] 2. The soil carbon sequestration and improvement agent application method provided by the present invention has a wide range of applications and can be widely used in carbon sequestration in heavily saline soils;
[0026] 3. The soil carbon fixation and enhancement and modifier addition method provided by the present invention can improve the utilization efficiency of the useful components in the modifier by salt marsh plants, and can also effectively and evenly apply the modifier to the salt marsh soil, thereby improving the treatment efficiency of the modifier. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 This is the preparation process of Spartina alterniflora biochar.
[0028] Figure 2 FTIR spectra of Spartina alterniflora biochar prepared at different firing temperatures.
[0029] Figure 3 Changes in soil hydrolytic enzyme activity after soil carbon sequestration and amendment addition.
[0030] Figure 4 The soil microbial community structure after soil carbon sequestration and amendment addition.
[0031] Figure 5 The number of OTUs of soil bacterial communities after soil carbon fixation and amendment addition. DETAILED DESCRIPTION
[0032] The present invention will be further described below in conjunction with the embodiments.
[0033] Embodiment 1:
[0034] (1) Preparation of experimental soil: Randomly select sampling points from the coastal beach, use a soil drill to collect 0-20 cm of soil, bag it and bring it back to the laboratory. Manually remove fine roots and other plant residues (>2 mm) in the sampled soil. Pass the soil through a 2 mm sieve, thoroughly homogenize it, and air dry it. The soil is activated at 25°C and 60% of the maximum water holding capacity. The soil is weighed every 1 day during the activation period and pre-incubated for 14 days.
[0035] (2) Preparation of soil carbon sequestration and amendments: Harvest the aboveground part of S. alterniflora at maturity, rinse it, and dry it at 60°C to constant weight. Then, cut it into small pieces with scissors and crush it with a grinder. Pass it through a 100-mesh sieve (0.149 mm) for later use. Place the plant powder in a crucible and compact it, wrap it tightly with tin foil, and place it in a muffle furnace for high-temperature pyrolysis treatment. The pyrolysis temperature is 350°C and the treatment time is 1 hour. After the biochar is burned, unload the burned biochar and cool it to below 60°C at room temperature.
[0036] (3) Mix the biochar with the soil at a carbon-to-soil ratio of 1:(3-5) (w:w), place the mixed soil in a 200 ml plastic jar, and adjust the soil moisture content to 60% of the maximum water holding capacity. During the entire incubation process, ventilation and water loss should be reduced by assembling a plastic cover with holes (each hole is 3 mm, a total of 9 holes). At the same time, the soil moisture content is kept constant by weighing and adding deionized water. The culture was carried out at a constant temperature and humidity of 25°C for 30 weeks.
[0037] (4) Destructive sampling was carried out at 180 days and 360 days. The test indicators include soil physical indicators (mechanical composition, bulk density, moisture content), chemical indicators (pH, water-soluble salt content, total organic carbon content), and biological indicators (soil hydrolase activity (sucrase, urease, alkaline phosphatase, protease), soil microbial community structure), so as to calculate the effects of soil improvement and carbon sequestration.
[0038] Embodiment 2:
[0039] (1) Preparation of experimental soil: Randomly select sampling points from the coastal beach, use a soil drill to collect 0-20 cm of soil, bag it and bring it back to the laboratory. Manually remove fine roots and other plant residues (>2 mm) in the sampled soil. Pass the soil through a 2 mm sieve, thoroughly homogenize it, and air dry it. The soil is activated at 25°C and 60% of the maximum water holding capacity. The soil is weighed every 1 day during the activation period and pre-incubated for 14 days.
[0040] (2) Preparation of soil carbon sequestration and amendments: Harvest the aboveground part of S. alterniflora at maturity, rinse it, and dry it at 60°C to constant weight. Then, cut it into small pieces with scissors and crush it with a grinder. Pass it through a 100-mesh sieve (0.149 mm) for later use. Place the plant powder in a crucible and compact it, wrap it tightly with tin foil, and place it in a muffle furnace for high-temperature pyrolysis treatment at a pyrolysis temperature of 450°C for 1 hour. After the biochar is burned, unload the burned biochar and cool it to below 60°C at room temperature.
[0041] (3) Mix the biochar with the soil at a carbon-to-soil ratio of 1:(3-5) (w:w), place the mixed soil in a 200 ml plastic jar, and adjust the soil moisture content to 60% of the maximum water holding capacity. During the entire incubation process, ventilation and water loss must be reduced, which can be achieved by assembling a plastic cover with holes (each hole is 3 mm, a total of 9 holes). At the same time, the soil moisture content is kept constant by weighing and adding deionized water. The culture was carried out at a constant temperature and humidity of 25°C for 30 weeks.
[0042] (4) Destructive sampling was carried out at 180 days and 360 days. The test indicators include soil physical indicators (mechanical composition, bulk density, moisture content), chemical indicators (pH, water-soluble salt content, total organic carbon content), and biological indicators (soil hydrolase activity (sucrase, urease, alkaline phosphatase, protease), soil microbial community structure), so as to calculate the effects of soil improvement and carbon sequestration.
[0043] Embodiment 3:
[0044] (1) Preparation of experimental soil: Randomly select sampling points from the coastal beach, use a soil drill to collect 0-20 cm of soil, bag it and bring it back to the laboratory. Manually remove fine roots and other plant residues (>2 mm) in the sampled soil. Pass the soil through a 2 mm sieve, thoroughly homogenize it, and air dry it. The soil is activated at 25°C and 60% of the maximum water holding capacity. The soil is weighed every 1 day during the activation period and pre-incubated for 14 days.
[0045] (2) Preparation of soil carbon sequestration and amendments: Harvest the aboveground part of S. alterniflora at maturity, rinse it, and dry it at 60°C to constant weight. Then, cut it into small pieces with scissors and crush it with a grinder. Pass it through a 100-mesh sieve (0.149 mm) for later use. Place the plant powder in a crucible and compact it, wrap it tightly with tin foil, and place it in a muffle furnace for high-temperature pyrolysis treatment. The pyrolysis temperature is 550°C and the treatment time is 1 hour. After the biochar is burned, unload the burned biochar and cool it to below 60°C at room temperature.
[0046] (3) Mix the biochar with the soil at a carbon-to-soil ratio of 1:(3-5) (w:w), place the mixed soil in a 200 ml plastic jar, and adjust the soil moisture content to 60% of the maximum water holding capacity. During the entire incubation process, ventilation and water loss must be reduced, which can be achieved by assembling a plastic cover with holes (each hole is 3 mm, a total of 9 holes). At the same time, the soil moisture content is kept constant by weighing and adding deionized water. The culture was carried out at a constant temperature and humidity of 25°C for 30 weeks.
[0047] (4) Destructive sampling was carried out at 180 days and 360 days. The test indicators include soil physical indicators (mechanical composition, bulk density, moisture content), chemical indicators (pH, water-soluble salt content, total organic carbon content), and biological indicators (soil hydrolase activity (sucrase, urease, alkaline phosphatase, protease), microbial community structure), so as to calculate the effects of soil improvement and carbon sequestration.
[0048] like Figure 2 As shown in the figure, the surface of biochar prepared from Spartina alterniflora contains a large number of oxygen-containing functional groups such as -OH free radicals, -C=O, -CO / -COC. These acidic or alkaline oxygen-containing functional groups help to improve the buffering capacity of the soil, and are also beneficial to enhance the adsorption of nutrient ions and organic matter, and increase the soil's fertilizer retention capacity. As the pyrolysis temperature rises, some characteristic peaks of oxygen-containing functional groups gradually disappear, indicating that the condensation degree of the carbon chain of the biochar increases during the pyrolysis process, and some oxygen-containing functional groups break, cross-link, and cyclize, becoming more aromatic, and the stability is enhanced, which means that the carbon fixation potential of the biochar increases.
[0049] After applying the soil conditioner, the nutrient content in the soil was significantly improved. The total nitrogen content increased by 0.07%, and the total phosphorus content increased by 0.26% (Table 1). The improvement of soil nutrients can promote plant growth and reduce carbon loss in coastal salt marsh wetlands.
[0050] After applying soil conditioners, the total carbon and microbial biomass carbon content in the soil were significantly increased. The total carbon content increased by 1.99%, and the microbial biomass carbon increased by 1.76% (Table 2). This shows that the addition of soil conditioners can directly increase the total organic carbon content in the soil and supplement the carbon source required for microbial activity.
[0051] Table 1 Nutrient enhancement effect obtained in the embodiment
[0052]
[0053] Table 2 Soil carbon enhancement effect achieved in the examples
[0054]
[0055]
[0056] At the end of the incubation experiment, the activity of hydrolytic protease in the experimental soil was measured. The results were as follows: Figure 3 As shown. Among them, A, B, and C correspond to the soil additive addition ratios of 1:3, 1:4, and 1:5, respectively, and H3, H4, H5, and H6 correspond to the pyrolysis temperatures of 300°C, 400°C, 500°C, and 600°C for preparing biochar in soil conditioners, respectively. The results of soil enzyme activity determination showed that ( Figure 3), compared with the non-addition treatment group, all soil amendment treatments increased the activities of protease, phosphatase, urease and sucrase in the soil. Compared with the non-addition treatment group, the protease activity in the soil with the addition of Spartina alterniflora soil amendment increased significantly by 41.46%-132.91% (P<0.05); the alkaline phosphatase activity increased significantly by 30.66%-172.76% (P<0.05); the urease activity increased significantly by 4.40%-332.10% (P<0.05); and the sucrase activity increased significantly by 6.04%-179.91% (P<0.05). Soil enzyme activity participates in a variety of soil functional processes and can be used as an indicator of soil ecological changes in arid and semi-arid ecosystems. Spartina alterniflora soil amendment can improve soil nutrients, water and ventilation conditions, and promote the occurrence of enzymatic reactions. At the same time, the pores of biochar in the Spartina alterniflora soil conditioner can dissolve oxygen in the pore water, increase the soil oxygen content, and thus increase enzyme activity. However, the effect of biochar on soil enzyme activity is affected by the biochar burning temperature, biochar material and addition amount. In this experiment, all treatment groups significantly increased soil enzyme activity. Among them, the biochar produced by pyrolysis at 400℃-600℃ had a more significant effect on improving soil enzyme activity.
[0057] At the end of the cultivation experiment, Illumina HiSeq high-throughput sequencing technology was used to measure and analyze the changes in microbial population richness at the phylum level in the experimental soil. Among them, A, B, and C correspond to soil additive addition ratios of 1:3, 1:4, and 1:5, respectively, and H3, H4, H5, and H6 correspond to the pyrolysis temperatures of biochar prepared in soil conditioners of 300°C, 400°C, 500°C, and 600°C, respectively. The measurement results show that ( Figure 4 , Figure 5 ), the total OUT mainly belonged to 11 phyla and 713 genera. Among them, the relatively abundant phyla were Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Chloroflexi. All addition treatments shared 713 OTUs. Except for the H3A treatment, the number of unique OTUs in all other treatments was lower than that in the CK treatment group. The number of unique OTUs in the soil after adding biochar prepared from Spartina alterniflora was greater than that in the soil after adding reed biochar. In general, the addition of biochar reduced the richness of soil microorganisms. As the pyrolysis temperature of biochar increased, the degree of decrease in the richness of soil microorganisms after adding it gradually increased.
[0058] The specific embodiments listed above are only for explaining the present invention, but not limited to the present invention. All other embodiments obtained by ordinary technicians in this field without creative work are, in principle, within the scope of protection of the present invention.
Claims
1. A method for preparing a carbon fixation and sink enhancement agent for heavily saline soil, characterized in that: The following steps are involved: The Spartina alterniflora straw is collected, crushed, subjected to high temperature pyrolysis treatment at 350°C-550°C for 40-80 minutes, and cooled to obtain the Spartina alterniflora biomass charcoal, which is the heavy saline soil carbon fixation and sink and improver.
2. The method for preparing the carbon fixation and sink enhancement and improver of heavy saline soil according to claim 1, characterized in that: Before the Spartina alterniflora straw is crushed, it is first dried to constant weight; the crushing is performed by a crusher, and the powder is passed through a 100-mesh sieve (0.149 mm) for later use; during the high-temperature pyrolysis treatment, the Spartina alterniflora straw powder is tightly wrapped with tin foil and subjected to high-temperature pyrolysis in a crucible.
3. A carbon fixation and sink enhancement agent for heavily saline soil, characterized in that: The heavily saline soil carbon fixation and sink and improver is the Spartina alterniflora biomass charcoal prepared by the preparation method described in claim 1 or 2.
4. Use of the heavily saline soil carbon fixation and sink enhancement agent and improver as described in claim 3 in improving heavily saline soil.
5. The use according to claim 4, characterized in that: The improvement of heavily saline soil includes changing its physical and chemical properties, nutrient content and microbial community structure.
6. The use according to claim 4, characterized in that: The method of improving the heavily saline soil includes improving the carbon fixation effect of salt marsh plants and heavily saline soil, and increasing the organic carbon content.
7. The use according to claim 6, characterized in that: The salt marsh plants include one or more of Spartina alterniflora, Suaeda salsa, and Phragmites australis.
8. A method for carbon fixation and improvement of heavily saline soil, characterized in that: The method comprises improving the heavily saline soil by using the heavily saline soil carbon fixation and carbon sink enhancement and improver as described in claim 3.
9. The method for carbon sequestration and improvement of heavily saline soil according to claim 8, characterized in that: The following steps are involved: Spread the Spartina alterniflora biochar at a charcoal-to-soil ratio (w:w) of 1:(3-5) on the heavily saline soil where carbon fixation and carbon sink enhancement are required, and mix it evenly with the surface soil.
10. The method for carbon sequestration and improvement of heavily saline soil according to claim 9, characterized in that: The surface soil refers to the soil layer from 0 to 30 cm below the soil surface.