Preparation method of clay mineral and charcoal composite base fertilizer

Abstract

The invention provides a preparation method of a clay mineral and charcoal composite base fertilizer. The preparation method comprises the following steps: mixing clay minerals with water to prepare a clay suspension; mixing a biomass raw material with the clay suspension, and drying to obtain a clay mineral biomass mixture; pyrolyzing the clay mineral biomass mixture to obtain a clay mineral biochar composite material; mixing the clay mineral biochar composite material with a compost raw material, and fermenting and decomposing to obtain the clay mineral and biochar composite base fertilizer. The preparation method of the clay mineral and biochar composite base fertilizer is simple and convenient, does not need to add other chemical preparations in the preparation process, can obviously improve the organic matter content and the fertilizer efficiency, and is pollution-free and pollution-free.

Description

Technical Field

[0001] The present application relates to the field of composting technology, and in particular to a method for preparing a composite base fertilizer of clay minerals and biochar. Background Art

[0002] According to statistics, the total amount of agricultural solid waste generated in my country is about 5 billion tons per year, but the treatment rate is less than 25%. Among them, livestock and poultry manure accounts for the largest proportion, with an annual output of 2.69 billion tons, followed by crop straw, about 1.09 billion tons. Excessive application of chemical fertilizers and random stacking of livestock and poultry manure are the main sources of agricultural non-point source pollution. Therefore, the partial replacement of chemical fertilizers with organic fertilizers is an important way to control agricultural non-point source pollution.

[0003] Aerobic composting technology is an important means to make rural organic waste harmless and recycle it. Using humus-rich compost as organic fertilizer or soil conditioner can not only improve soil aggregate structure and passivate soil heavy metals, but also promote plant growth, with good environmental, ecological and economic benefits. However, there are defects such as uneven quality, poor fertilizer efficiency and low humus content in current aerobic compost products, which limit the application and promotion of organic fertilizer products. Therefore, there is an urgent need for a preparation method of compost products to overcome the problems of poor fertilizer efficiency and low organic matter content of current traditional compost products. Summary of the invention

[0004] In view of this, the purpose of the present application is to propose a method for preparing a composite base fertilizer of clay minerals and biochar to solve the related problems mentioned in the background technology.

[0005] Based on the above purpose, the present application provides a method for preparing a clay mineral and biochar composite base fertilizer, comprising: mixing a clay mineral with water to prepare a clay suspension; mixing a biomass raw material with the clay suspension, and drying the mixture to obtain a clay mineral biomass mixture; pyrolyzing the clay mineral biomass mixture to obtain a clay mineral biochar composite material; mixing the clay mineral biochar composite material with a compost raw material, and fermenting and decomposing the mixture to obtain a clay mineral and biochar composite base fertilizer.

[0006] Furthermore, the clay mineral includes montmorillonite and / or nontronite, and the mass ratio of the clay mineral to the water is 1:40.

[0007] Furthermore, the step of mixing the clay mineral with water to prepare the clay suspension includes: mixing the clay mineral with the water at room temperature, and performing ultrasonic treatment for 30 minutes to obtain the clay suspension.

[0008] Furthermore, the biomass raw material is selected from one or more of wheat straw, corn straw, pine wood and grape cuttings, and is obtained by passing through an 80-mesh sieve after being washed and air-dried; the mass ratio of the biomass raw material to the clay mineral is 1:5.

[0009] Furthermore, the mixing of the biomass raw material with the clay suspension and drying to obtain the clay mineral biomass mixture includes: adding the biomass raw material to the clay suspension, stirring and mixing for 1 hour, and drying in an oven at 80° C. to obtain the clay mineral biomass mixture.

[0010] Furthermore, the pyrolysis temperature is 500° C. to 700° C., and the pyrolysis time is 1 h to 2 h.

[0011] Furthermore, the pyrolysis of the clay mineral biomass mixture to obtain the clay mineral biochar composite material includes: placing the clay mineral biomass mixture into a crucible, wrapping the crucible with tin foil, placing it in a muffle furnace for pyrolysis, and then cooling it to room temperature to obtain the clay mineral biochar composite material.

[0012] Furthermore, the compost raw materials include livestock and poultry manure and straw, the livestock and poultry manure includes one or more of pig manure, cow manure, chicken manure and sheep manure, the straw is selected from one or more of wheat straw, corn straw, pine wood and grape cuttings, and is obtained by washing and air-drying and passing through a 20-mesh sieve. The mass ratio of the livestock and poultry manure to the straw is (2-5):1; the mass percentage of the clay mineral biochar composite material to the compost raw material is 10%.

[0013] Furthermore, the moisture content of the clay mineral biochar composite material after mixing with the compost raw material is 50% to 65%.

[0014] Furthermore, the fermentation and composting to obtain the clay mineral and biochar composite base fertilizer includes: performing aerobic fermentation in a static forced ventilation manner, and obtaining the clay mineral and biochar composite base fertilizer after 2 to 4 months of fermentation and composting.

[0015] As can be seen from the above, the preparation method of the clay mineral and biochar composite base fertilizer provided by the present application includes: mixing clay mineral with water to prepare a clay suspension; mixing biomass raw materials with clay suspension, drying to obtain a clay mineral biomass mixture; pyrolyzing the clay mineral biomass mixture to obtain a clay mineral biochar composite material; mixing the clay mineral biochar composite material with compost raw materials, fermenting and decomposing to obtain a clay mineral and biochar composite base fertilizer. The composite material is prepared by combining clay minerals with biochar, and then mixed with compost raw materials to prepare a composite base fertilizer, which has stronger thermal stability and more stable carbon skeleton. Due to the developed pore structure of the composite material, it has a large specific surface area and more chemical functional groups, and can adsorb and stabilize the nutrients in the fertilizer, and has significant slow release ability. After application, the amount of fertilizer used can be reduced, the utilization rate of nutrients can be improved, soil properties can be improved, and the increase in yield and income of crops can be promoted. The raw materials of the base fertilizer are all readily available natural environment-friendly materials, which can not only turn waste into treasure, but also have a simple preparation process, which greatly reduces the actual operation requirements and costs. The test showed that the clay mineral and biochar composite base fertilizer prepared by the method can significantly increase the organic matter content in the fertilizer and improve the seed germination rate. Compared with the base fertilizer obtained by using clay minerals or biochar alone, the effect after superposition is better. The preparation method of the clay mineral and biochar composite base fertilizer is simple and convenient. No other chemical agents need to be added during the preparation process. It can significantly increase the organic matter content and fertilizer efficiency, and is harmless and pollution-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present application or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 This is a schematic diagram of a process for preparing a clay mineral and biochar composite base fertilizer in an embodiment of the present application;

[0018] Figure 2 This is a scanning schematic diagram of the clay mineral biochar composite material in the embodiment of the present application;

[0019] Figure 3 This is an X-ray diffraction diagram of the clay mineral biochar composite material in the embodiment of the present application;

[0020] Figure 4 This is a Fourier infrared spectrum of the clay mineral biochar composite material in the embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments.

[0022] It should be noted that, unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods, unless otherwise specified, are all conventional methods.

[0023] According to statistics, the total amount of agricultural solid waste generated in my country is about 5 billion tons per year, but the treatment rate is less than 25%. Among them, livestock and poultry manure accounts for the largest proportion, with an annual output of 2.69 billion tons, followed by crop straw, about 1.09 billion tons. Excessive application of chemical fertilizers and random stacking of livestock and poultry manure are the main sources of agricultural non-point source pollution. Therefore, the partial replacement of chemical fertilizers with organic fertilizers is an important way to control agricultural non-point source pollution.

[0024] Aerobic composting technology is an important means to make rural organic waste harmless and recycle it. Using humus-rich compost as organic fertilizer or soil conditioner can not only improve soil aggregate structure and passivate soil heavy metals, but also promote plant growth, with good environmental, ecological and economic benefits. However, there are defects such as uneven quality, poor fertilizer efficiency and low humus content in current aerobic compost products, which limit the application and promotion of organic fertilizer products. Therefore, there is an urgent need for a preparation method of compost products to overcome the problems of poor fertilizer efficiency and low organic matter content of current traditional compost products.

[0025] At present, the main aerobic composting processes include pile-type, trough-type and reactor-type composting. According to the ventilation method, pile-type composting is divided into strip-type and static ventilation pile-type. The strip-type system is to pile the mixture of straw and feces into a narrow and long pile, and maintain ventilation and oxygen supply through mechanical pile turning; the static ventilation pile type is to pile the fermented raw materials into piles, and then ventilate the pile through aeration equipment such as blowers and ventilation pipes.

[0026] Biochar is a porous solid material produced by pyrolysis of organic solid waste such as agricultural waste and livestock and poultry manure under high temperature and anoxic conditions. It has the characteristics of large specific surface area, strong adsorption performance, high stability and easy post-processing. It is widely used in the fields of agricultural ecological restoration. Biochar comes from agricultural waste, is used in agricultural waste composting, and is applied to soil, which has become a hot topic of research in recent years. Adding a certain amount of biochar to aerobic composting can optimize the composting process, accelerate the composting process, and thus improve the quality of the compost.

[0027] Clay minerals are widely distributed in nature. Due to their layered structure, high surface area and high ion exchange capacity, they are often used as adsorbents because of their low mining cost and environmental friendliness. Clay minerals can be used to reduce greenhouse gas emissions and nitrogen losses during composting, promote humification, and thus improve the quality of compost products.

[0028] It is possible to consider mixing clay minerals with biochar and preparing organic fertilizer through aerobic composting. However, since biochar and clay minerals are both powdery and relatively loose, and the first requirement that needs to be met in the preparation of compound fertilizers is stability, the preparation method needs to be further improved.

[0029] Below, through specific embodiments and combined Figures 1 to 4 To describe the technical solution of this application in detail.

[0030] In some embodiments of the present application, a method for preparing a clay mineral and biochar composite fertilizer is provided, such as Figure 1 As shown, the following steps are included:

[0031] S1. Mixing clay minerals with water to prepare a clay suspension.

[0032] The clay minerals include montmorillonite and / or nontronite, and the mass ratio of the clay minerals to water is 1:40.

[0033] The clay mineral is mixed with water to prepare a clay suspension, including: mixing the clay mineral with water at room temperature, and performing ultrasonic treatment for 30 minutes to obtain a clay suspension.

[0034] S2. Mixing the biomass raw material with the clay suspension, and drying the mixture to obtain a clay mineral biomass mixture.

[0035] The biomass raw material is selected from one or more of wheat straw, corn straw, pine wood and grape cuttings, and is obtained by passing through an 80-mesh sieve after washing and air-drying, for example, a mixture of wheat straw and corn straw, etc., and is not specifically limited; the mass ratio of the biomass raw material to the clay mineral is 1:5.

[0036] The biomass raw material is mixed with the clay suspension and dried to obtain a clay mineral biomass mixture, including: adding the biomass raw material to the clay suspension, stirring and mixing for 1 hour, and drying in an oven at 80° C. to obtain the clay mineral biomass mixture.

[0037] S3. Pyrolyzing the clay mineral biomass mixture to obtain a clay mineral biochar composite material.

[0038] The pyrolysis temperature is 500°C to 700°C, for example, 500°C, 550°C, 600°C, 650°C or 700°C, etc., without specific limitation; the pyrolysis time is 1h to 2h, for example, 1h, 1.5h or 2h, etc., without specific limitation.

[0039] The clay mineral biomass mixture is pyrolyzed to obtain a clay mineral biochar composite material, including: placing the clay mineral biomass mixture in a crucible, wrapping the crucible with tin foil, placing it in a muffle furnace for pyrolysis, and then cooling it to room temperature to obtain a clay mineral biochar composite material. During the pyrolysis process, the biomass pyrolysis releases volatile organic compounds, thereby forming pores of varying sizes. The presence of a porous structure provides a channel for the migration of substances in the environment. At the same time, the surface of the material is also covered with fine mineral particles in the form of agglomerates, some of which have entered the pores.

[0040] S4, mixing the clay mineral biochar composite material with compost raw materials, and fermenting and decomposing them to obtain a clay mineral and biochar composite base fertilizer.

[0041] The compost raw materials include livestock and poultry manure and straw, the livestock and poultry manure includes one or more of pig manure, cow manure, chicken manure and sheep manure, for example, a mixture of pig manure and cow manure, etc., without specific limitation; the straw is selected from one or more of wheat straw, corn straw, pine wood and grape shear branches, and is obtained by washing and air-drying and passing through a 20-mesh sieve, for example, a mixture of wheat straw and corn straw, etc., without specific limitation; the mass ratio of livestock and poultry manure to the straw is (2-5):1, and the mass ratio is, for example, 2:1, 3:1, 4:1 or 5:1, etc., without specific limitation.

[0042] The mass percentage of the clay mineral biochar composite material and the compost raw material is 10%, and the moisture content of the clay mineral biochar composite material after mixing with the compost raw material is 50% to 65%. The moisture content is, for example, 50%, 55%, 60% or 65%, etc., and is not specifically limited.

[0043] Fermentation and composting are performed to obtain a composite base fertilizer of clay minerals and biochar, comprising: performing aerobic fermentation in a static forced ventilation manner, and obtaining the composite base fertilizer of clay minerals and biochar after 2 to 4 months of fermentation and composting. The fermentation and composting time is, for example, 60 days, 70 days, 80 days, 90 days, 100 days, 110 days or 120 days, etc., and is not specifically limited.

[0044] The composite material is prepared by combining clay minerals and biochar, and then mixed with compost raw materials to prepare composite base fertilizer. The thermal stability is stronger and the carbon skeleton is more stable. Due to the developed pore structure of the composite material, it has a large specific surface area and more chemical functional groups, which can adsorb and stabilize the nutrients in the fertilizer. At the same time, it has a significant slow-release ability. After application, it can reduce the amount of fertilizer used, improve the utilization rate of nutrients, improve soil properties, and promote the increase of crop yields and incomes. The raw materials of the base fertilizer are all readily available natural and environmentally friendly materials, which can not only turn waste into treasure, but also have a simple preparation process, greatly reducing the actual operation requirements and costs. After testing, the clay mineral and biochar composite base fertilizer prepared by this method can significantly increase the organic matter content in the fertilizer and improve the seed germination rate. Compared with the base fertilizer obtained by using clay minerals or biochar alone, the effect of superposition is better.

[0045] The method for preparing the clay mineral and biochar composite base fertilizer is simple and convenient, and no other chemical agents need to be added during the preparation process. The method can significantly increase the organic matter content and fertilizer efficiency, and is non-toxic and pollution-free.

[0046] Example 1

[0047] 50 g of montmorillonite was weighed and added to 2 L of deionized water, mixed and ultrasonicated at room temperature for 30 min to obtain a clay suspension.

[0048] Add 250 g of wheat straw to the clay suspension, stir for 1 hour, and dry in an oven at 80°C. Put the obtained clay mineral biomass mixture into a ceramic crucible with a lid, wrap it with tin foil, place it in a muffle furnace at 600°C for pyrolysis for 1 hour, cool it to room temperature and take it out to obtain a clay mineral biochar composite material.

[0049] A clay mineral biochar composite material with a mass ratio of 10% of the compost raw material is added to the compost raw material with a mass ratio of sheep manure and wheat straw of 1:2, and the mixture is fully mixed. The moisture content is adjusted to 60%, and aerobic fermentation is carried out by static forced ventilation. After 66 days of full fermentation and decomposition (in winter), a clay mineral and biochar composite base fertilizer can be obtained.

[0050] Comparative Example 1

[0051] The compost material of sheep manure and wheat straw in a mass ratio of 1:2 is fully mixed evenly without adding other substances, the moisture content is adjusted to 60%, and aerobic fermentation is carried out by static forced ventilation. After 66 days of full fermentation and decomposition (in winter), organic base fertilizer can be obtained.

[0052] The organic matter content and pH test were performed on the basal fertilizers of Example 1 and Comparative Example 1, and the seed germination rate was tested using the basal fertilizers. The test results are shown in Table 1.

[0053] Table 1 Base fertilizer test table

[0054]

[0055]

[0056] It can be seen from Table 1 that the composite base fertilizer prepared in Example 1 has a higher seed germination index. Applying the base fertilizer to the soil can not only ensure the supply of crop nutrients, but also give full play to the ability of biochar to fix carbon, reduce emissions and improve soil properties.

[0057] Comparative Example 2

[0058] Add montmorillonite at a mass ratio of 10% of the mass ratio of the compost raw material to the compost raw material with a mass ratio of sheep manure to wheat straw of 1:2, mix well, adjust the moisture content to 60%, and perform aerobic fermentation by static forced ventilation. After 66 days of full fermentation and decomposition (in winter), clay mineral base fertilizer can be obtained.

[0059] Comparative Example 3

[0060] Weigh 250 g of wheat straw, put it into a ceramic crucible with a lid, wrap it with tin foil, place it in a muffle furnace at 600 °C for pyrolysis for 1 h, cool it to room temperature and take it out to obtain biochar.

[0061] Add biochar at a mass ratio of 10% of the mass ratio of the compost raw material to the compost raw material with a mass ratio of sheep manure and wheat straw of 1:2, mix them thoroughly, adjust the moisture content to 60%, and perform aerobic fermentation by static forced ventilation. After 66 days of full fermentation and decomposition (in winter), the biochar-based fertilizer can be obtained.

[0062] The seed germination rate was tested using the base fertilizers of Comparative Examples 2 and 3. The test results are shown in Table 2. Taking Comparative Example 1 as a benchmark, the data of Comparative Examples 2 and 3 were significantly worse than the data of Example 1, indicating that the combination of clay minerals and biochar can enhance the composting effect, and the effect of Example 1 is significantly better than the effect of the superposition of Comparative Examples 2 and 3, indicating that clay minerals and biochar have a synergistic effect on fertilizer efficiency.

[0063] Table 2 Fertilizer efficiency test table

[0064] project Comparative Example 1 Example 1 Comparative Example 2 Comparative Example 3 Seed germination index (%) 104 152 113 108

[0065] The clay mineral biochar composite material in Example 1 was tested by scanning electron microscopy, and the results are as follows: Figure 2As shown in the figure, during the pyrolysis process, biomass pyrolysis releases volatile organic compounds, thus forming pores of varying sizes. The presence of a porous structure provides a channel for the migration of substances in the environment. At the same time, the surface of the material is also covered with fine mineral particles in the form of agglomerates, some of which have entered the pores. Combined with the presence of inorganic mineral elements such as calcium, magnesium, aluminum and silicon in the energy spectrum analysis, it shows that montmorillonite has been loaded into the biochar structure, and the pores of the modified composite material are more regular and neat.

[0066] The clay mineral biochar composite material in Example 1 and the wheat straw biochar in Comparative Example 3 were subjected to XRD tests. The test results are as follows: Figure 3 As shown in the figure, both biochars of the two materials have a broad and stable diffraction peak at about 22°, which may be the (002) diffraction peak of the disordered carbon structure of the biochar. The high-intensity diffraction peak at 26.8° is mainly due to the presence of quartz (SiO2), which is a common inorganic component in straw biochar. In addition, by comparing with the standard card of montmorillonite (PDF#29-1496), it is found that the composite material of Example 1 has a strong diffraction peak at 19.9°. 35.0° and 62.0° Three characteristic diffraction peaks of montmorillonite appeared at , indicating that montmorillonite was successfully loaded on the surface of the biochar matrix.

[0067] The clay mineral biochar composite material in Example 1, the montmorillonite in Comparative Example 2, and the wheat straw and wheat straw biochar in Comparative Example 3 were tested by FT-IR. The test results are as follows: Figure 4 As shown, OH bond stretching (3200 cm -1 ~3500cm -1 ), aliphatic, asymmetric and symmetric CH bond stretching (2800 cm -1 ~2900cm -1 ), C=O bond stretching (1700cm -1 )、CH deformation (1600m -1 ), aromatic ring vibration (1200-1500cm -1 ) and CO stretching vibration (900cm -1 ~1100cm -1 ). In the spectrum of montmorillonite, 3626cm -1 and 3422cm -1 The stretching vibration of the OH bond at 1034-915 cm-1 may be due to the hydroxyl structure associated with Al and Si in clay minerals. In addition, the characteristic peaks of Si-O and Al-OH in the montmorillonite spectrum appear at approximately 1034-915 cm-1. -1In the spectrum of clay mineral biochar composites, 3422 cm -1 The band near 3626 cm-1 disappeared, and the intensity at 3626 cm-1 decreased. This phenomenon may be due to the elimination of -OH groups by high-temperature pyrolysis. In addition, after high-temperature pyrolysis, the peaks of -OH, -CH, C=O, and OC=O groups weakened or disappeared, which is due to the desorption and carbonization of all adsorbed water. Compared with the spectrum of montmorillonite, the 1034 cm-1 in the spectrum of clay mineral biochar composites -1 The band at (Si-O-Si stretching) shifts to a higher frequency (1062cm -1 ) moved, which may be due to the hindrance in the synthesis of composite materials. After pyrolysis, at 472cm -1 、517cm -1 and 797cm -1 The characteristic peaks observed at are attributed to Si-O-Si stretching, Si-O-Al stretching and Si-O stretching, respectively.

[0068] Figures 2 to 4 It shows that the carbon skeleton of the composite base fertilizer of Example 1 is more stable and has strong thermal stability. Since the composite material has a developed pore structure, a large specific surface area and more chemical functional groups, it can adsorb and stabilize nutrients in the fertilizer and has significant slow-release ability. After application, it can reduce the amount of fertilizer used, improve the utilization rate of nutrients, improve soil properties, and promote the increase of crop production and income.

[0069] The various embodiments in the present application are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0070] The description of the present application is given for the purpose of illustration and description, and is not intended to be exhaustive or to limit the present application to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present application, and to enable those of ordinary skill in the art to understand the present application and thus design various embodiments with various modifications suitable for specific purposes.

[0071] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application (including the claims) is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0072] Although the present application has been described in conjunction with specific embodiments thereof, many alternatives, modifications and variations of these embodiments will be apparent to those skilled in the art in light of the foregoing description.

[0073] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims

1. A method for preparing a clay mineral and biochar composite fertilizer, characterized in that: include: Mixing clay mineral with water to prepare a clay suspension; Mixing the biomass raw material with the clay suspension, and drying the mixture to obtain a clay mineral biomass mixture; pyrolyzing the clay mineral biomass mixture to obtain a clay mineral biochar composite material; The clay mineral biochar composite material is mixed with compost raw materials, and fermented and decomposed to obtain a clay mineral and biochar composite base fertilizer.

2. The method for preparing the clay mineral and biochar composite base fertilizer according to claim 1, characterized in that: The clay mineral includes montmorillonite and / or nontronite, and the mass ratio of the clay mineral to the water is 1:

40.

3. The method for preparing the clay mineral and biochar composite base fertilizer according to claim 1, characterized in that: The step of mixing clay minerals with water to prepare a clay suspension comprises: The clay mineral and the water are mixed at room temperature and subjected to ultrasonic treatment for 30 minutes to obtain a clay suspension.

4. The method for preparing the clay mineral and biochar composite base fertilizer according to claim 1, characterized in that: The biomass raw material is selected from one or more of wheat straw, corn straw, pine wood and grape cuttings, and is obtained by washing and air-drying and then passing through an 80-mesh sieve; the mass ratio of the biomass raw material to the clay mineral is 1:

5.

5. The method for preparing the clay mineral and biochar composite base fertilizer according to claim 1, characterized in that: The method of mixing the biomass raw material with the clay suspension and drying the mixture to obtain a clay mineral biomass mixture comprises: The biomass raw material was added to the clay suspension and stirred for 1 hour, and then dried in an oven at 80° C. to obtain the clay mineral biomass mixture.

6. The method for preparing the clay mineral and biochar composite base fertilizer according to claim 1, characterized in that: The pyrolysis temperature is 500° C. to 700° C., and the pyrolysis time is 1 h to 2 h.

7. The method for preparing the clay mineral and biochar composite base fertilizer according to claim 1, characterized in that: The step of pyrolyzing the clay mineral biomass mixture to obtain a clay mineral biochar composite material comprises: The clay mineral biomass mixture is placed in a crucible, and the crucible is wrapped with tin foil and placed in a muffle furnace for pyrolysis, and then cooled to room temperature to obtain the clay mineral biochar composite material.

8. The method for preparing the clay mineral and biochar composite base fertilizer according to claim 1, characterized in that: The compost raw materials include livestock and poultry manure and straw, the livestock and poultry manure includes one or more of pig manure, cow manure, chicken manure and sheep manure, the straw is selected from one or more of wheat straw, corn straw, pine wood and grape shear branches, and is obtained by washing and air-drying and passing through a 20-mesh sieve. The mass ratio of the livestock and poultry manure to the straw is (2-5):1; the mass percentage of the clay mineral biochar composite material to the compost raw material is 10%.

9. The method for preparing the clay mineral and biochar composite base fertilizer according to claim 1, characterized in that: The moisture content of the clay mineral biochar composite material after being mixed with the compost raw material is 50% to 65%.

10. The method for preparing the clay mineral and biochar composite base fertilizer according to claim 1, characterized in that: The method of obtaining a composite base fertilizer of clay minerals and biochar by fermentation and composting comprises: Aerobic fermentation is carried out in a static forced ventilation manner, and the clay mineral and biochar composite base fertilizer is obtained after 2 to 4 months of fermentation and decomposition.

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